CN113504352A - Method for determining dredging depth and engineering quantity of ecological dredging engineering - Google Patents
Method for determining dredging depth and engineering quantity of ecological dredging engineering Download PDFInfo
- Publication number
- CN113504352A CN113504352A CN202110642548.6A CN202110642548A CN113504352A CN 113504352 A CN113504352 A CN 113504352A CN 202110642548 A CN202110642548 A CN 202110642548A CN 113504352 A CN113504352 A CN 113504352A
- Authority
- CN
- China
- Prior art keywords
- sediment
- dredging
- depth
- heavy metal
- total
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
- 238000000034 method Methods 0.000 title claims abstract description 44
- 239000013049 sediment Substances 0.000 claims abstract description 254
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 claims abstract description 222
- 238000005070 sampling Methods 0.000 claims abstract description 168
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims abstract description 134
- 229910001385 heavy metal Inorganic materials 0.000 claims abstract description 127
- 229910052757 nitrogen Inorganic materials 0.000 claims abstract description 111
- 229910052698 phosphorus Inorganic materials 0.000 claims abstract description 105
- 239000011574 phosphorus Substances 0.000 claims abstract description 105
- OAICVXFJPJFONN-UHFFFAOYSA-N Phosphorus Chemical compound [P] OAICVXFJPJFONN-UHFFFAOYSA-N 0.000 claims abstract description 102
- 239000003344 environmental pollutant Substances 0.000 claims abstract description 50
- 231100000719 pollutant Toxicity 0.000 claims abstract description 50
- 238000009826 distribution Methods 0.000 claims abstract description 28
- 238000011835 investigation Methods 0.000 claims abstract description 6
- 230000008859 change Effects 0.000 claims description 89
- 238000010586 diagram Methods 0.000 claims description 70
- XKMRRTOUMJRJIA-UHFFFAOYSA-N ammonia nh3 Chemical compound N.N XKMRRTOUMJRJIA-UHFFFAOYSA-N 0.000 claims description 15
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 claims description 14
- MMDJDBSEMBIJBB-UHFFFAOYSA-N [O-][N+]([O-])=O.[O-][N+]([O-])=O.[O-][N+]([O-])=O.[NH6+3] Chemical compound [O-][N+]([O-])=O.[O-][N+]([O-])=O.[O-][N+]([O-])=O.[NH6+3] MMDJDBSEMBIJBB-UHFFFAOYSA-N 0.000 claims description 14
- JVMRPSJZNHXORP-UHFFFAOYSA-N ON=O.ON=O.ON=O.N Chemical compound ON=O.ON=O.ON=O.N JVMRPSJZNHXORP-UHFFFAOYSA-N 0.000 claims description 13
- 229910019142 PO4 Inorganic materials 0.000 claims description 12
- 239000010452 phosphate Substances 0.000 claims description 12
- NBIIXXVUZAFLBC-UHFFFAOYSA-K phosphate Chemical compound [O-]P([O-])([O-])=O NBIIXXVUZAFLBC-UHFFFAOYSA-K 0.000 claims description 12
- 239000010802 sludge Substances 0.000 claims description 10
- 239000011701 zinc Substances 0.000 claims description 9
- 229910052785 arsenic Inorganic materials 0.000 claims description 8
- 229910052793 cadmium Inorganic materials 0.000 claims description 8
- 238000010276 construction Methods 0.000 claims description 8
- 239000011133 lead Substances 0.000 claims description 8
- 229910052753 mercury Inorganic materials 0.000 claims description 8
- 229910052759 nickel Inorganic materials 0.000 claims description 8
- 229910052725 zinc Inorganic materials 0.000 claims description 8
- RQNWIZPPADIBDY-UHFFFAOYSA-N arsenic atom Chemical compound [As] RQNWIZPPADIBDY-UHFFFAOYSA-N 0.000 claims description 7
- 229910052804 chromium Inorganic materials 0.000 claims description 7
- 239000011651 chromium Substances 0.000 claims description 7
- 238000001514 detection method Methods 0.000 claims description 7
- 239000003651 drinking water Substances 0.000 claims description 7
- 235000020188 drinking water Nutrition 0.000 claims description 7
- QSHDDOUJBYECFT-UHFFFAOYSA-N mercury Chemical compound [Hg] QSHDDOUJBYECFT-UHFFFAOYSA-N 0.000 claims description 7
- 230000008569 process Effects 0.000 claims description 7
- 229910052802 copper Inorganic materials 0.000 claims description 6
- 239000010949 copper Substances 0.000 claims description 6
- 230000001988 toxicity Effects 0.000 claims description 6
- 231100000419 toxicity Toxicity 0.000 claims description 6
- 238000003911 water pollution Methods 0.000 claims description 6
- VYZAMTAEIAYCRO-UHFFFAOYSA-N Chromium Chemical compound [Cr] VYZAMTAEIAYCRO-UHFFFAOYSA-N 0.000 claims description 5
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 claims description 5
- HCHKCACWOHOZIP-UHFFFAOYSA-N Zinc Chemical compound [Zn] HCHKCACWOHOZIP-UHFFFAOYSA-N 0.000 claims description 5
- BDOSMKKIYDKNTQ-UHFFFAOYSA-N cadmium atom Chemical compound [Cd] BDOSMKKIYDKNTQ-UHFFFAOYSA-N 0.000 claims description 5
- 238000012544 monitoring process Methods 0.000 claims description 5
- 230000004044 response Effects 0.000 claims description 4
- VHUUQVKOLVNVRT-UHFFFAOYSA-N Ammonium hydroxide Chemical compound [NH4+].[OH-] VHUUQVKOLVNVRT-UHFFFAOYSA-N 0.000 claims description 3
- 239000000126 substance Substances 0.000 claims description 3
- 230000000694 effects Effects 0.000 abstract description 7
- 230000009286 beneficial effect Effects 0.000 abstract 1
- 239000010410 layer Substances 0.000 description 22
- 239000002689 soil Substances 0.000 description 21
- 238000011156 evaluation Methods 0.000 description 12
- 238000011160 research Methods 0.000 description 7
- 238000011109 contamination Methods 0.000 description 5
- 238000003321 atomic absorption spectrophotometry Methods 0.000 description 4
- 235000015097 nutrients Nutrition 0.000 description 4
- 230000009467 reduction Effects 0.000 description 4
- 150000003839 salts Chemical class 0.000 description 4
- 238000004364 calculation method Methods 0.000 description 3
- 238000003795 desorption Methods 0.000 description 3
- 229910052751 metal Inorganic materials 0.000 description 3
- 239000002184 metal Substances 0.000 description 3
- 238000001179 sorption measurement Methods 0.000 description 3
- 230000009471 action Effects 0.000 description 2
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 2
- 238000004140 cleaning Methods 0.000 description 2
- 230000007613 environmental effect Effects 0.000 description 2
- 238000002795 fluorescence method Methods 0.000 description 2
- 150000002739 metals Chemical class 0.000 description 2
- 230000033116 oxidation-reduction process Effects 0.000 description 2
- 229910052760 oxygen Inorganic materials 0.000 description 2
- 239000001301 oxygen Substances 0.000 description 2
- 238000002336 sorption--desorption measurement Methods 0.000 description 2
- 239000002352 surface water Substances 0.000 description 2
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 1
- 241000195493 Cryptophyta Species 0.000 description 1
- 238000007696 Kjeldahl method Methods 0.000 description 1
- 238000010521 absorption reaction Methods 0.000 description 1
- 239000003513 alkali Substances 0.000 description 1
- 229910052787 antimony Inorganic materials 0.000 description 1
- 239000002585 base Substances 0.000 description 1
- 238000005520 cutting process Methods 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 230000004069 differentiation Effects 0.000 description 1
- 238000006073 displacement reaction Methods 0.000 description 1
- 238000004993 emission spectroscopy Methods 0.000 description 1
- 238000012851 eutrophication Methods 0.000 description 1
- 230000002349 favourable effect Effects 0.000 description 1
- 238000004401 flow injection analysis Methods 0.000 description 1
- 239000010439 graphite Substances 0.000 description 1
- 229910002804 graphite Inorganic materials 0.000 description 1
- 238000011065 in-situ storage Methods 0.000 description 1
- 238000009616 inductively coupled plasma Methods 0.000 description 1
- 230000009191 jumping Effects 0.000 description 1
- 229910052745 lead Inorganic materials 0.000 description 1
- 238000012417 linear regression Methods 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 238000005065 mining Methods 0.000 description 1
- 238000002156 mixing Methods 0.000 description 1
- 230000035945 sensitivity Effects 0.000 description 1
- 238000004088 simulation Methods 0.000 description 1
- 239000000243 solution Substances 0.000 description 1
- 238000002798 spectrophotometry method Methods 0.000 description 1
- 238000010561 standard procedure Methods 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
- 239000000758 substrate Substances 0.000 description 1
- 239000002344 surface layer Substances 0.000 description 1
- 230000009466 transformation Effects 0.000 description 1
- 238000000844 transformation Methods 0.000 description 1
- 239000003643 water by type Substances 0.000 description 1
Images
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N33/00—Investigating or analysing materials by specific methods not covered by groups G01N1/00 - G01N31/00
- G01N33/24—Earth materials
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N33/00—Investigating or analysing materials by specific methods not covered by groups G01N1/00 - G01N31/00
- G01N33/18—Water
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N33/00—Investigating or analysing materials by specific methods not covered by groups G01N1/00 - G01N31/00
- G01N33/18—Water
- G01N33/1813—Specific cations in water, e.g. heavy metals
Landscapes
- Life Sciences & Earth Sciences (AREA)
- Health & Medical Sciences (AREA)
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Biochemistry (AREA)
- Immunology (AREA)
- Physics & Mathematics (AREA)
- Analytical Chemistry (AREA)
- Food Science & Technology (AREA)
- General Health & Medical Sciences (AREA)
- General Physics & Mathematics (AREA)
- Medicinal Chemistry (AREA)
- Pathology (AREA)
- Environmental & Geological Engineering (AREA)
- General Life Sciences & Earth Sciences (AREA)
- Geology (AREA)
- Remote Sensing (AREA)
- Treatment Of Sludge (AREA)
Abstract
The invention relates to a method for determining dredging depth and engineering quantity of an ecological dredging project, which comprises the following steps: setting sampling points in a preset ecological dredging range of a target water area and carrying out sediment investigation; determining control values of all aspects under comprehensive consideration; determining the dredging depth of the area where each sampling point is located according to the layered overall distribution characteristics of the bottom sediment pollutants of all the sampling points and the vertical distribution characteristics of the total nitrogen content, the total phosphorus content and the heavy metal potential ecological risk index of the bottom sediment of each sampling point; and calculating the dredging engineering quantity by combining the dredging area according to the dredging depth. The invention comprehensively considers factors such as the bottom sediment pollution characteristic of the target water area, scientifically and accurately determines the dredging depth and the engineering quantity, avoids over-small or over-large dredging depth, and is beneficial to realizing good ecological dredging effect.
Description
Technical Field
The invention relates to a method for determining dredging depth and engineering quantity of an ecological dredging project, belonging to the technical field of ecological environment protection.
Background
In the comprehensive treatment of lake water environment, the ecological dredging of lakes is an important component. Taking the Changdong lake in the lake basin as an example, the Changdong lake belongs to a lake river network with relatively serious siltation, needs to be subjected to moderate ecological dredging, and is further favorable for solving the problems of serious bottom mud pollution, less aquatic plant distribution, reduced aquatic organism diversity, multiple blue algae blooms and the like. For dredging of lake sediment, if the dredging depth is not enough, the treatment effect is difficult to achieve, and if the dredging depth is too deep, the ecology of the lake is easy to destroy, so that the reasonable dredging depth needs to be analyzed and determined in a targeted manner, so that the aim of appropriate ecological dredging is achieved. Therefore, a corresponding determination method is urgently needed to be developed, and the desilting depth and the engineering quantity of the ecological desilting engineering can be accurately determined.
Through search, the invention patent applications with application numbers CN202010111904.7 and CN111254870A disclose a method for determining the dredging depth of river and lake bottom mud by using a nitrogen and phosphorus adsorption and desorption method, and the method comprises the steps of collecting a bottom mud sample and an overlying surface water sample; carrying out adsorption and desorption, and determining the concentration of ammonia nitrogen; mixing the bottom sediment sample with simulated water and an overlying surface water sample, carrying out adsorption and desorption, and determining the total phosphorus concentration; calculating the adsorption/desorption amount; a linear regression equation is established for the initial concentration and the amount of adsorption/desorption. The present invention is different from the prior art represented by the technical proposal.
Disclosure of Invention
The main purposes of the invention are: the method can comprehensively consider factors such as bottom sediment pollution characteristics of a target water area and the like, scientifically and accurately determine the dredging depth and the engineering quantity, avoid over-small or over-large dredging depth and facilitate realization of a good ecological dredging effect.
The technical scheme for solving the technical problems of the invention is as follows:
a method for determining the dredging depth and the engineering quantity of an ecological dredging project is characterized by comprising the following steps:
firstly, setting sampling points in a preset ecological dredging range of a target water area and carrying out sediment investigation;
secondly, determining a total nitrogen content control value and a total phosphorus content control value of the sediment according to the total nitrogen content and the total phosphorus content of all sampling points of the columnar sediment samples and a water body monitoring report of a target water area by combining the existing data; determining a heavy metal potential ecological risk index control value of the sediment according to the heavy metal potential ecological risk indexes of all sampling point columnar sediment samples and by combining whether a target water area contains a resident drinking water source area or not; determining a thickness control value of the sediment according to the sediment thickness of all sampling points and by combining the vertical controllable precision of the dredging engineering construction;
thirdly, determining the dredging depth of the area where each sampling point is located according to the layered overall distribution characteristics of the bottom sediment pollutants of all the sampling points, and the vertical distribution characteristics of the total nitrogen content, the total phosphorus content and the heavy metal potential ecological risk index of the bottom sediment of each sampling point;
and step four, calculating the dredging engineering quantity according to the dredging depth of the region where each sampling point is located and the dredging area of the region where each sampling point is located.
The method is based on the sediment investigation result, and mainly adopts the classification standard of nitrogen, phosphorus and heavy metal to comprehensively evaluate the sediment pollutant layered distribution characteristic in the preset ecological dredging range of the target water area, and determines the dredging depth and the engineering quantity. The method can comprehensively consider factors such as bottom sediment pollution characteristics of a target water area, scientifically and accurately determine the dredging depth and the engineering quantity, avoid over-small or over-large dredging depth and facilitate realization of a good ecological dredging effect.
The technical scheme of the invention is further perfected as follows:
preferably, in the first step, the density of the sampling points is more than 15/10 km2(ii) a Respectively collecting a columnar sediment sample at each sampling point, wherein the bottom end of the columnar sediment sample is at least 5cm of hard river sediment; the sediment survey comprises: firstly, dividing each columnar sediment sample from top to bottom according to a fixed length, then measuring the pollutant content of each layer of sample after each columnar sediment sample is divided, and calculating the pollutant content of each columnar sediment sample, wherein the pollutant content comprises total nitrogen content, total phosphorus content and heavy metal content; and measuring the thickness of the bottom mud.
More preferably, the fixed length is 5-10 cm; after each column-shaped bottom mud is divided, the uppermost layer sample is closest to the water surface, and the lowermost layer sample is farthest from the water surface; the heavy metal comprises copper, zinc, lead, cadmium, nickel, total chromium, arsenic and mercury.
By adopting the preferred scheme, the specific technical details of the first step can be further optimized.
Preferably, in the second step, the existing data includes papers or reports of lake sediment ecological dredging projects at home and abroad, and an assessment report of total sediment pollution of a basin to which the target water area belongs; the total nitrogen content control value is selected from the lower limit value of the total nitrogen content of the bottom sludge corresponding to the water pollution degree in the existing data at the preset level, and the total phosphorus content control value is selected from the lower limit value of the total phosphorus content of the bottom sludge corresponding to the water pollution degree in the existing data at the preset level;
the potential ecological risk index of the heavy metal is calculated according to the following steps:
calculating the potential risk index of each heavy metal:
wherein the content of the first and second substances,
the pollution coefficient of the current heavy metal is obtained;
the content of the heavy metal in the bottom mud is measured in mg/kg;
mg/kg for calculating the required reference value;
is the potential risk index of the heavy metal;
is a toxicity response parameter of the heavy metal; i is the order of the heavy metal speciesNumbering;
and then calculating the potential ecological risk index of the heavy metal in the bottom mud:
wherein RI is the potential ecological risk index of heavy metal in the bottom sediment, n is the total amount of heavy metal species, i,
The same as before;
and taking the minimum value of the vertical controllable precision of the dredging engineering construction as the thickness control value of the bottom mud.
More preferably, the preset grade is the most serious pollution grade when determining the total nitrogen content control value and the total phosphorus content control value of the bottom mud; in determining the heavy metal potential ecological risk index control value of the sediment, the heavy metal potential ecological risk index control value is selected from 150, 300, 600, 1200, and when the target water area contains the residential drinking water source, the heavy metal potential ecological risk index control value is 150 or 300.
By adopting the preferred scheme, the specific technical details of the second step can be further optimized. Wherein, regarding the thickness control value, for example, if the lowest value of the vertical controllable accuracy of the current dredging project construction is 10cm, the thickness control value of the sediment is set to 10 cm.
Preferably, in the third step, the specific process of obtaining the layered overall distribution characteristics of the sediment pollutants at all sampling points comprises: calculating and drawing a total nitrogen content change diagram, a total phosphorus content change diagram and a heavy metal potential ecological risk index change diagram which change with depth in the sediment of the total region according to the pollutant content of each layer of samples after the columnar sediment of all sampling points is segmented;
the specific process for obtaining the vertical distribution characteristics of the total nitrogen content, the total phosphorus content and the potential ecological risk index of the heavy metal of the sediment at each sampling point comprises the following steps: and aiming at each sampling point, calculating and drawing a total nitrogen content change diagram, a total phosphorus content change diagram and a heavy metal potential ecological risk index change diagram of the sampling point along with the depth change according to the pollutant content of each layer of sample after the sampling point is divided by the columnar sediment.
More preferably, the third step comprises:
s1, respectively judging whether the total nitrogen content, the total phosphorus content and the heavy metal potential ecological risk index of the sediment have a general trend changing along with different depths of the sediment according to a total nitrogen content change diagram, a total phosphorus content change diagram and a heavy metal potential ecological risk index change diagram in the sediment pollutant layered overall distribution characteristics of all sampling points, and respectively judging a sediment depth range of which the total nitrogen content is greater than or equal to a total nitrogen content control value, a sediment depth range of which the total phosphorus content is greater than or equal to a total phosphorus content control value and a sediment depth range of which the heavy metal potential ecological risk index is greater than or equal to a heavy metal potential ecological risk index control value; taking the judgment result as a reference;
s2, aiming at each sampling point, judging whether the sediment thickness of the sampling point is smaller than a thickness control value, if so, removing the area represented by the sampling point from a preset ecological dredging range;
s3, evaluating each layer of sample after the columnar sediment at each sampling point is divided, namely: in the vertical distribution characteristics of the total nitrogen content, the total phosphorus content and the heavy metal potential ecological risk index of the sediment at the sampling point, determining a sediment depth horizon with the total nitrogen content greater than or equal to a total nitrogen content control value according to a total nitrogen content change diagram, determining a sediment depth horizon with the total phosphorus content greater than or equal to a total phosphorus content control value according to a total phosphorus content change diagram, and determining a sediment depth horizon with the heavy metal potential ecological risk index greater than or equal to a heavy metal potential ecological risk index control value according to a heavy metal potential ecological risk index change diagram; the bottom sediment depth layer refers to the depth range of the bottom sediment of each layer of samples after the columnar bottom sediment is divided; selecting the deepest sediment depth from all the sediment depth horizons as the desilting depth of the area represented by the sampling point;
s4, judging whether the sediment thickness of each sampling point is less than or equal to the dredging depth, if so, taking the thickness control value as the dredging depth of the area represented by the sampling point;
the area represented by the sampling points refers to an area obtained by expanding the sampling points by adopting a GIS space interpolation method under the preset interpolation parameters.
After the preferable scheme is adopted, the determination of the dredging depth can be more scientific and accurate through a more comprehensive judgment process, and the omission can be avoided as much as possible.
More preferably, in S3, if the pollutant indexes of the shallow sediment at the sampling point are all smaller than the corresponding pollutant index control values, and the pollutant indexes of the deep sediment at the sampling point are all greater than or equal to the corresponding pollutant index control values, the area represented by the sampling point is removed from the preset ecological dredging range; the pollutant indexes comprise total nitrogen content, total phosphorus content and heavy metal potential ecological risk index;
taking the maximum sediment depth of the resuspension of the surface sediment of the target water area caused by hydrodynamic conditions as a depth limit value; the shallow sediment refers to a columnar sediment segmented sample with the depth less than or equal to a depth threshold value; the deep bed mud refers to a sample obtained after the column-shaped bed mud with the depth larger than the depth threshold value is segmented.
After the preferred scheme is adopted, the area of the type can be further accurately identified, and the situation that the deep heavy polluted bottom sediment in the area directly contacts with the overlying water body to release pollutants after dredging is avoided.
Preferably, the first step further comprises: placing a balanced type gap water sampling device as a water sampling point at a preset site in a preset ecological dredging range of a target water area, and detecting the nitrate nitrogen content, the ammonium nitrogen content, the nitrite nitrogen content and the phosphate content of each sample after sampling;
the third step further comprises: aiming at each water sampling point, calculating and drawing a nitrate nitrogen content change diagram, a nitrite nitrogen content change diagram, an ammonium nitrogen content change diagram, a phosphate content change diagram and an inorganic nitrogen content change diagram of the water sampling point along with the change of the depth near the interface according to the detection result of each sample of the water sampling point;
s1 of the third step further includes: and judging whether the sediment near the interface is a pollution source of the overlying water nitrogen phosphorus pollution or not according to the content change graphs of the water sampling points, and listing the judgment result as a reference.
More preferably, the balanced type gap water sampling device is vertically arranged and longitudinally spans a bottom sediment gap water-overlying water interface after being arranged; the sampling precision of the balanced type gap water sampling device is 1.25 +/-0.05 cm; and the balanced interstitial water sampling device is balanced for 10-15 days after being placed, and a sample is taken out and detected.
After the preferable scheme is adopted, the sediment clearance water-overlying water can be further analyzed to better ensure scientific and accurate determination of the dredging depth, and further avoid leakage.
Compared with the prior art, the method is based on the investigation result of the sediment, and mainly adopts the classification standard of nitrogen, phosphorus and heavy metal to comprehensively evaluate the layering distribution characteristics of the sediment pollutants in the preset ecological dredging range of the target water area and determine the dredging depth and the engineering quantity. The method can comprehensively consider factors such as bottom sediment pollution characteristics of a target water area, scientifically and accurately determine the dredging depth and the engineering quantity, avoid over-small or over-large dredging depth and facilitate realization of a good ecological dredging effect.
Drawings
FIG. 1 is a diagram showing the spatial distribution of the thickness of bottom mud in example 2 of the present invention.
Fig. 2 to 4 are a total nitrogen content variation graph, a total phosphorus content variation graph and a heavy metal potential ecological risk index variation graph of the total regional sediment according to the depth variation in the embodiment 3 of the present invention.
FIG. 5 is a graph showing the change of the potential ecological risk index of heavy metals in sediment of 0-5cm, 5-10cm and 10-15cm in example 3 of the present invention.
FIGS. 6 to 8 are the evaluation graphs of the potential ecological risk index areas of the heavy metals in the bottom sediment of 0 to 5cm, 5 to 10cm and 10 to 15cm in the example 3 of the invention.
Fig. 9 to 14 are respectively a nitrate nitrogen content change diagram, a nitrite nitrogen content change diagram, an ammonium nitrogen content change diagram, a phosphate content change diagram, and an inorganic nitrogen content change diagram of water sampling points P1 to P6 in example 3 of the present invention.
Fig. 15 is a schematic view of the dredging depth of the ecological dredging project implementation area in embodiment 3 of the present invention.
Detailed Description
In specific implementation, the method for determining the dredging depth and the engineering quantity of the ecological dredging engineering comprises the following steps:
firstly, setting sampling points in a preset ecological dredging range of a target water area and carrying out sediment investigation.
Wherein the density of the sampling points is more than 15/10 km2(ii) a Respectively collecting a columnar sediment sample at each sampling point, wherein the bottom end of the columnar sediment sample is at least 5cm of hard river sediment; the sediment survey comprises the following steps: firstly, dividing each columnar sediment sample from top to bottom according to a fixed length, then measuring the pollutant content of each layer of sample after each columnar sediment sample is divided, and calculating the pollutant content of each columnar sediment sample, wherein the pollutant content comprises the total nitrogen content, the total phosphorus content and the heavy metal content; and measuring the thickness of the bottom mud. Specifically, the fixed length is 5-10 cm; after each column-shaped bottom mud is divided, the uppermost layer sample is closest to the water surface, and the lowermost layer sample is farthest from the water surface; the heavy metals include copper, zinc, lead, cadmium, nickel, total chromium, arsenic, and mercury.
Secondly, determining a total nitrogen content control value and a total phosphorus content control value of the sediment according to the total nitrogen content and the total phosphorus content of all sampling points of the columnar sediment samples and a water body monitoring report of a target water area by combining the existing data; determining a heavy metal potential ecological risk index control value of the sediment according to the heavy metal potential ecological risk indexes of all sampling point columnar sediment samples and by combining whether a target water area contains a resident drinking water source area or not; and determining the thickness control value of the sediment according to the sediment thickness of all sampling points and by combining the vertical controllable precision of the dredging engineering construction.
Wherein the existing data comprises papers or reports of lake sediment ecological dredging projects at home and abroad and an assessment report of total sediment pollution of a basin to which a target water area belongs; the total nitrogen content control value is selected from the lower limit value of the total nitrogen content of the bottom sludge corresponding to the water pollution degree in the existing data at the preset level, and the total phosphorus content control value is selected from the lower limit value of the total phosphorus content of the bottom sludge corresponding to the water pollution degree in the existing data at the preset level;
the potential ecological risk index of the heavy metal is calculated according to the following steps:
calculating the potential risk index of each heavy metal:
wherein the content of the first and second substances,
the pollution coefficient of the current heavy metal is obtained;
the content of the heavy metal in the bottom mud is measured in mg/kg;
mg/kg for calculating the required reference value;
is the potential risk index of the heavy metal;
is a toxicity response parameter of the heavy metal; i is the serial number of the heavy metal species;
and then calculating the potential ecological risk index of the heavy metal in the bottom mud:
wherein RI is the potential ecological risk index of heavy metal in the bottom sediment, n is the total amount of heavy metal species, i,
The same as before;
and taking the minimum value of the vertical controllable precision of the dredging engineering construction as the thickness control value of the bottom mud.
When determining a total nitrogen content control value and a total phosphorus content control value of the bottom mud, presetting the grade as the most serious pollution grade; in determining the heavy metal potential ecological risk index control value of the sediment, the heavy metal potential ecological risk index control value is selected from 150, 300, 600, 1200, and when the target water area contains the residential drinking water source, the heavy metal potential ecological risk index control value is 150 or 300.
And thirdly, determining the dredging depth of the area where each sampling point is located according to the layered overall distribution characteristics of the bottom sediment pollutants of all the sampling points, and the vertical distribution characteristics of the total nitrogen content, the total phosphorus content and the heavy metal potential ecological risk index of the bottom sediment of each sampling point.
Wherein, the concrete process of the sediment pollutant layering overall distribution characteristic of all sampling points of acquisition is: calculating and drawing a total nitrogen content change diagram, a total phosphorus content change diagram and a heavy metal potential ecological risk index change diagram which change with depth in the sediment of the total region according to the pollutant content of each layer of samples after the columnar sediment of all sampling points is segmented;
the specific process for obtaining the vertical distribution characteristics of the total nitrogen content, the total phosphorus content and the potential ecological risk index of the heavy metal of the sediment at each sampling point comprises the following steps: and aiming at each sampling point, calculating and drawing a total nitrogen content change diagram, a total phosphorus content change diagram and a heavy metal potential ecological risk index change diagram of the sampling point along with the depth change according to the pollutant content of each layer of sample after the sampling point is divided by the columnar sediment.
Specifically, the third step includes:
s1, respectively judging whether the total nitrogen content, the total phosphorus content and the heavy metal potential ecological risk index of the sediment have a general trend changing along with different depths of the sediment according to a total nitrogen content change diagram, a total phosphorus content change diagram and a heavy metal potential ecological risk index change diagram in the sediment pollutant layered overall distribution characteristics of all sampling points, and respectively judging a sediment depth range of which the total nitrogen content is greater than or equal to a total nitrogen content control value, a sediment depth range of which the total phosphorus content is greater than or equal to a total phosphorus content control value and a sediment depth range of which the heavy metal potential ecological risk index is greater than or equal to a heavy metal potential ecological risk index control value; taking the judgment result as a reference;
s2, aiming at each sampling point, judging whether the sediment thickness of the sampling point is smaller than a thickness control value, if so, removing the area represented by the sampling point from a preset ecological dredging range;
s3, evaluating each layer of sample after the columnar sediment at each sampling point is divided, namely: in the vertical distribution characteristics of the total nitrogen content, the total phosphorus content and the heavy metal potential ecological risk index of the sediment at the sampling point, determining a sediment depth horizon with the total nitrogen content greater than or equal to a total nitrogen content control value according to a total nitrogen content change diagram, determining a sediment depth horizon with the total phosphorus content greater than or equal to a total phosphorus content control value according to a total phosphorus content change diagram, and determining a sediment depth horizon with the heavy metal potential ecological risk index greater than or equal to a heavy metal potential ecological risk index control value according to a heavy metal potential ecological risk index change diagram; the sediment depth layer refers to the sediment depth range of each layer of samples after the columnar sediment is segmented; selecting the deepest sediment depth from all the sediment depth horizons as the desilting depth of the area represented by the sampling point;
s4, judging whether the sediment thickness of each sampling point is less than or equal to the dredging depth, if so, taking the thickness control value as the dredging depth of the area represented by the sampling point;
the area represented by the sampling point is an area obtained by expanding the sampling point by adopting a GIS space interpolation method under a preset interpolation parameter.
In S3, if the pollutant indexes of the shallow sediment at the sampling point are all smaller than the corresponding pollutant index control values, and the pollutant indexes of the deep sediment at the sampling point are all greater than or equal to the corresponding pollutant index control values, removing the area represented by the sampling point from the preset ecological dredging range; the pollutant indexes comprise total nitrogen content, total phosphorus content and heavy metal potential ecological risk index;
taking the maximum sediment depth of the resuspension of the surface sediment of the target water area caused by hydrodynamic conditions as a depth limit value; the shallow sediment refers to a sample obtained after the column-shaped sediment with the depth less than or equal to the depth threshold value is segmented; the deep bed mud refers to a sample obtained after the column-shaped bed mud with the depth larger than the depth threshold value is segmented.
And step four, calculating the dredging engineering quantity according to the dredging depth of the region where each sampling point is located and the dredging area of the region where each sampling point is located.
In addition, the first step further comprises: placing a balanced type gap water sampling device as a water sampling point at a preset site in a preset ecological dredging range of a target water area, and detecting the nitrate nitrogen content, the ammonium nitrogen content, the nitrite nitrogen content and the phosphate content of each sample after sampling;
the third step further comprises: aiming at each water sampling point, calculating and drawing a nitrate nitrogen content change diagram, a nitrite nitrogen content change diagram, an ammonium nitrogen content change diagram, a phosphate content change diagram and an inorganic nitrogen content change diagram of the water sampling point along with the change of the depth near the interface according to the detection result of each sample of the water sampling point;
s1 of the third step further includes: and judging whether the sediment near the interface is a pollution source of the overlying water nitrogen phosphorus pollution or not according to the content change graphs of the water sampling points, and listing the judgment result as a reference.
The balanced type gap water sampling device is vertically arranged and longitudinally spans a bottom sediment gap water-overlying water interface after being arranged; the sampling precision of the balanced gap water sampling device is 1.25 +/-0.05 cm; and (5) balancing for 10-15 days after the balance type gap water sampling device is placed, taking out and detecting a sample.
The invention is described in further detail below with reference to embodiments and with reference to the drawings. The invention is not limited to the examples given.
Example 1
This embodiment is the first step in the practice of the present invention, and the basic contents are as described above.
The following is a detailed example of the present embodiment.
In the preset ecological dredging range of a certain target water area, a total of 85 mining plants are arrangedSampling points with a density of 19.9/10 km2. The longest length of the columnar sediment sample collected at each sampling point is about 80cm, the shortest length is about 15cm, and hard river sediment with the length of at least 5cm is collected.
All cutting apart according to the fixed length from top to bottom to each column bed mud sample, specifically do: 0-5cm, 5-10cm, 10-15cm, 15-20cm, 20-25cm, 25-30cm, 30-35cm, 35-40cm, 40-45cm, 45-50cm, 50-60cm, 60-70cm, 70-80cm, and the like. Then, detection is performed.
In addition, a balanced gap water sampling device (Peer) is placed at 6 preset points to serve as a water sampling point, bottom sediment gap water/overlying water samples are collected, and the sampling precision is 1.25 cm. When the device is placed, the sampling device is vertically inserted into the sediment, and the length of the sampling device is ensured to be at least 5cm above the water-overlying water interface of the sediment gap and at least 30cm below the interface, namely the sampling device longitudinally spans the water-overlying water interface of the sediment gap. After standing, the sample is taken out and tested by balancing for 10-15 days.
And for each layer of sample after the columnar sediment is divided, determining the content of pollutants by adopting the following detection method:
(1) total phosphorus: alkali fusion-molybdenum-antimony anti-spectrophotometry for measuring total phosphorus in soil (HJ 632-;
(2) total nitrogen: kjeldahl method for determination of total nitrogen in soil quality (HJ 717-2014);
(3) copper and zinc: flame atomic absorption spectrophotometry for measuring soil quality copper and zinc (GB/T17138-1997);
(4) lead and cadmium: determination of lead and cadmium in soil quality graphite furnace atomic absorption spectrophotometry (GB/T17141-1997);
(5) nickel: flame atomic absorption spectrophotometry for measuring soil mass nickel (GB/T17139-);
(6) total chromium: determination of Total chromium in soil flame atomic absorption Spectrophotometry (HJ 491-;
(7) arsenic: determination of total mercury, total arsenic, and total lead in soil mass by atomic fluorescence method part 2: determination of total arsenic in soil (GB/T22105.2-2008);
(8) mercury: determination of total mercury, total arsenic, and total lead by soil mass atomic fluorescence method part 1: determination of total mercury in soil (GB/T22105.1-2008).
For the sediment interstitial water/overlying water sample, the following detection method is adopted to determine the pollutant content:
the contents of nitrate nitrogen, ammonium nitrogen, nitrite nitrogen and phosphate are measured by a flow injection method, and the content of heavy metal is measured by an atomic absorption spectrophotometer method or inductively coupled plasma emission spectrometry (HJ 776-2015).
Example 2
This embodiment is the second step of the present invention, and the basic contents are as described above.
This example is based on example 1.
The following is a detailed example of the present embodiment.
Firstly, because the relation between the nitrogen and phosphorus content in the sediment and the nitrogen and phosphorus concentration of the overlying water body is relatively complex, the influence factors are more, the method has strong regional characteristics, and at present, no unified evaluation standard for the nitrogen and phosphorus nutrient salt content of the lake sediment exists.
Generally, the main method for judging whether the nitrogen and phosphorus nutrient salt content of the lake sediment can influence the overlying water body is to develop a simulation experiment of the lake in-situ or indoor sediment, and accordingly, the relation between the nitrogen and phosphorus nutrient salt content of each lake sediment and the release capacity of the overlying water body is established, so that the nitrogen and phosphorus pollution degree of the sediment is evaluated. However, this method requires the collection of a large number of column samples, is time-consuming and labor-consuming, and is less adopted in engineering practice.
The lake belonging to the target water area is one of the lakes which are most researched on the relation between overlying water bodies and eutrophication by developing the nitrogen and phosphorus nutrient salt content of bottom sludge in China, and has abundant research data, wherein the differentiation and evaluation standards of the total nitrogen and total phosphorus of the bottom sludge of the lake are shown in table 1.
TABLE 1 evaluation criteria for the degree of total nitrogen and total phosphorus contamination of the sludge (unit: mg/kg)
| Index (I) | Cleaning of | Slight pollution | Moderate pollution | Severe pollution |
| Total nitrogen | 1128 | 1377 | 1627 | >1627 |
| Total phosphorus | 434 | 497 | 625 | >625 |
| Class of water quality | Ⅲ | Ⅳ | Ⅴ | Inferior V |
In the table, the pollution degree of the lake sediment is divided into a plurality of grades of clean, light pollution, moderate pollution and severe pollution. Comparing the total nitrogen content and the total phosphorus content of the sediment measured in the example 1 with those in the table 1, the evaluation standard in the table 1 is also applicable to the sediment pollution condition of the target water area:
the statistical conditions of the total nitrogen and total phosphorus contents of the sediment in the target water area are as follows:
as shown in Table 2, the average values of the total nitrogen and phosphorus contents in the sediment were 1162.29mg/kg and 517.13mg/kg, respectively, and the maximum values of the respective indexes were 7.42 and 12.20 times the minimum values, respectively. The number proportion of samples with over medium pollution of total nitrogen and total phosphorus in the bottom sediment sample is 24.6 percent and 55.27 percent, and the maximum exceeding multiples are 1.25 and 1.45 respectively; the proportion of the number of samples exceeding the severe pollution is 9.27 percent and 25.08 percent, the maximum exceeding multiples are 0.91 and 0.95 respectively, and the exceeding proportion of the total phosphorus is obviously higher than that of the total nitrogen.
TABLE 2 Total nitrogen and phosphorus contents of the sludge
| Index (I) | Total nitrogen (mg/kg) | Total phosphorus (mg/kg) |
| Mean value of | 1162.29 | 517.13 |
| Maximum value | 3100 | 1220 |
| Minimum value | 418 | 100 |
| Median value | 1140 | 517.5 |
| Standard deviation of | 371.53 | 178.72 |
| Standard proportion (%) over moderate contamination (TN, TP) | 24.6 | 55.27 |
| Exceeding maximum standard exceeding multiple of moderate pollution (TN, TP) | 1.25 | 1.45 |
| Exceeding the Standard proportion of Severe contamination (TN, TP (%) | 9.27 | 25.08 |
| Exceeding the maximum exceeding multiple of severe pollution (TN, TP) standard | 0.91 | 0.95 |
The standard values in table 1 are used as evaluation bases, the total nitrogen content of the sediment in the target water area is 88% lower than the heavy pollution standard limit value, the total phosphorus content of the sediment in the target water area is 77% lower than the heavy pollution standard limit value, namely 12% of the total nitrogen of the sediment sample and 23% of the total phosphorus of the sediment sample are in a heavy pollution state. The details are shown in table 3.
TABLE 3 percentage displacement of nitrogen and phosphorus content of sediment in target water area according to standard value for nitrogen and phosphorus pollution assessment
According to a recent monitoring report of a target water area provided by an environment monitoring station, the annual maximum exceeding multiple of the total phosphorus concentration of the water body of the target water area exceeds 3 times, the maximum exceeding multiple of the total nitrogen concentration is 0.73 time, and the phosphorus pollution of the target water area is more serious than the nitrogen pollution on the whole, which is consistent with the evaluation result that the total phosphorus content of the sediment is in a serious pollution state in the evaluation result. In general, the evaluation criteria in Table 1 are also applicable to the sediment contamination of the target waters.
Therefore, the lower limit value of the heavy contamination level in table 1 is set as a control value, that is: the total nitrogen content control value was 1627mg/kg and the total phosphorus content control value was 625 mg/kg.
And (II) in order to evaluate the degree of interference of the heavy metal content of the sediment sample by human activities, the highest value of the heavy metal of the sediment before global industrialization or the background value of the sediment in a research area is usually selected as a reference value. The regional property of the sediment heavy metal background value is strong, and the interference degree of the sediment in the region by human activities can be relatively qualitatively reflected by taking the local heavy metal background value as a reference value. In the research, the soil heavy metal background value of the province where the target water area is located is used as a reference, and the relative background value of each sample is analyzed.
As national quality standards of bottom mud heavy metals are not established in China, the lake bottom mud is usually used for agriculture and forestry production or road greening after dredging, and the research is based on the soil environment quality standard (GB 15618 + 1995) and the greening planting soil standard (CJ/T340-2016) to evaluate the standard exceeding situation of the bottom mud pollutants in the target water area. The background values of heavy metals in the sediment and the second and third quality standards in soil environmental quality Standard (GB 15618-1995) and greening planting soil Standard (CJ/T340-2016) are shown in Table 4.
TABLE 4 background values for heavy metal reference in sediment, Standard for soil Environment quality (GB 15618-1995), Standard for soil for greening planting (CJ/T340-2016), Standard values for three-level quality
| Cr | Cu | Ni | Zn | As | Cd | Pb | Hg | |
| Reference background value (mg/kg) | 77.8 | 22.3 | 26.7 | 62.6 | 10 | 0.13 | 26.2 | 0.29 |
| GB15618-1995 class II standard (mg/kg) | 300 | 200 | 50 | 250 | 30 | 0.3 | 300 | 0.5 |
| GB15618-1995 class III Standard (mg/kg) | 400 | 400 | 200 | 500 | 30 | 1.0 | 500 | 1.5 |
| CJ/T340-2016 II grade standard (mg/kg) | 200 | 300 | 80 | 350 | 30 | 0.8 | 300 | 1.2 |
| CJ/T340-2016 III grade standard (mg/kg) | 250 | 400 | 150 | 500 | 35 | 1.2 | 450 | 1.5 |
The potential ecological risk index method is proposed by the swedish scholars Hakanson in 1980 and is a relatively quick, simple and standard method for dividing the pollution degree of bottom mud and the potential ecological risk of water areas. The potential ecological risk index value is calculated by measuring the content of pollutants in the sediment sample, and the content of sediment metals, the toxicity level of the metals and the sensitivity of water bodies to metal pollution can be reflected. The method is mainly used for evaluating heavy metals, and the pollution way is substrate sludge-water-organism-fish-human body. The specific calculation steps of the sediment heavy metal potential ecological risk index are as described above.
The sediment toxicity parameters and the pollution levels thereof required for the calculation of the potential ecological risk index are shown in tables 5 and 6.
TABLE 5 toxicity response parameters required for calculation of potential ecological risk index
TABLE 6 grading of pollution indicators and potential ecological risk indicators
The establishment of the identification and evaluation standard of the heavy metal polluted bottom sediment can refer to a potential ecological risk index method, and the bottom sediment with the potential ecological risk index being more than or equal to 300 is called the heavy metal polluted bottom sediment.
The following is the statistical condition of the heavy metal pollution of the sediment in the target water area:
the average contents of Cr, Cu, Ni, Zn, As, Cd, Pb and Hg in the sediment samples are 51.88mg/kg, 23.49mg/kg, 29.09mg/kg, 77.97mg/kg, 5.80mg/kg, 0.26mg/kg, 15.28mg/kg and 0.04mg/kg respectively. The variation range of each index content is large, wherein the amplitude of Cd content of the sediment is maximum, and the maximum value is 153 times of the minimum value; the second is the Hg content, the highest value is 116 times of the lowest value; the amplitude variation is relatively small and is Cr and Ni, and the highest value is 5 times of the lowest value.
By taking the background value of the heavy metal in the soil of the province of the target water area as a reference, the contents of other heavy metals except Hg in the sediment heavy metal elements in the research area exceed the background value, the element with the highest proportion exceeding the background value is Ni, the proportion of the overproof sample in the total is 77.80%, the proportion of the overproof sample in the total is Cd, and the maximum proportion of the overproof sample in the overproof sample is 58.85 times.
Comparing the 'II level' standard and the 'III level' standard in the 'soil environmental quality Standard' (GB 15618-1995), wherein the three indexes of Ni, Zn and Cd in the sediment of the research area exceed the II level standard, the proportion of the three heavy metal elements exceeding the II level standard is respectively 0.64%, 1.12% and 12.14%, and the maximum exceeding multiple is respectively 0.12, 0.44 and 24.93; wherein the samples of Cd exceed the III-grade standard, and the exceeding proportion and the multiple are respectively 4.95 percent and 6.78 times.
Taking greening planting soil standard (CJ/T340-2016) as an evaluation basis, only two indexes of Zn and Cd in sediment in a research area exceed the II-level standard, the proportion of two heavy metal element samples exceeding the II-level standard is 0.16% and 7.03%, and the maximum exceeding times are 0.03 and 8.73 respectively; wherein the samples of Cd exceed the III-grade standard, and the exceeding proportion and the multiple are respectively 4.47 percent and 5.48 times.
As shown in the table below, the average ecological risk index in the sediment was 87.22, with the maximum value of the index being 70.34 times the minimum value. The proportion of the ecological risk index of the heavy metal in the bottom sediment exceeding the higher risk standard and the high risk standard is 4.47 percent and 1.28 percent respectively, and the maximum exceeding multiple is 5.29 and 2.14 respectively.
| Index (I) | Ecological risk index |
| Mean value of | 87.22 |
| Maximum value | 1886.58 |
| Minimum value | 26.82 |
| Median value | 51.955 |
| Standard deviation of | 140.89 |
| Exceeding the higher Risk (RI) Standard proportion (%) | 4.47 |
| Exceeding a higher Risk (RI) standard maximum exceeding multiple | 5.29 |
| Over high Risk (RI) standard ratio (%) | 1.28 |
| Maximum exceeding multiple exceeding high Risk (RI) standard | 2.14 |
Considering that the target water area contains a resident drinking water source area, the heavy metal pollution of the sediment should be strictly controlled, and therefore, the heavy metal potential ecological risk index control value of the sediment is determined to be 300.
And (III) according to the sampling condition of the columnar sediment, obtaining the thickness spatial distribution condition of the sediment as shown in figure 1. In general, the sediment thickness of the target water area is distributed regionally, but thicker sediment exists in the area of a part of sampling points.
The area ratios of the sediment with different thicknesses in the target water area are shown in the following table, and the areas with the sediment thicknesses of 30-40cm and 10-20cm are the largest and the areas are respectively 11.62km2And 10.63km2(ii) a The thickness of the bottom mud is 50-60cm and>the area of 60cm is the minimum, and the area is 1.60km respectively2And 0.33km2。
| Depth of silt (cm) | <10 | 10-20 | 20-30 | 30-40 | 40-50 | 50-60 | >60 |
| Area (km)2) | 3.55 | 10.63 | 6.83 | 11.62 | 8.25 | 1.60 | 0.33 |
| Ratio (%) | 8.31％ | 24.82％ | 15.96％ | 27.15％ | 19.28％ | 3.73％ | 0.76％ |
Considering that the vertical controllable precision of the dredging engineering construction is 10cm at the lowest, the thickness control value of the bottom mud is set to be 10 cm.
Example 3
This embodiment is the third step of the present invention, and the basic contents are as described above.
This example is based on example 2.
The following is a detailed example of the present embodiment.
Firstly, obtaining the layered overall distribution characteristics of the bottom sediment pollutants at all sampling points.
And (3) calculating and drawing a total nitrogen content change diagram (figure 2), a total phosphorus content change diagram (figure 3) and a heavy metal potential ecological risk index change diagram (figure 4) of the sediment in the total region along with the depth change according to the pollutant content of each layer of sample after the columnar sediment of all sampling points is segmented.
And secondly, obtaining the vertical distribution characteristics of the total nitrogen content, the total phosphorus content and the potential ecological risk index of the heavy metal of the sediment at each sampling point.
And aiming at each sampling point, calculating and drawing a total nitrogen content change diagram, a total phosphorus content change diagram and a heavy metal potential ecological risk index change diagram of the sampling point along with the depth change according to the pollutant content of each layer of sample after the sampling point is divided by the columnar sediment. Taking the potential ecological risk index of the heavy metal of the sediment of 0-15cm as an example, the change diagram of the potential ecological risk index of the heavy metal of the sediment of 0-5cm, 5-10cm and 10-15cm is shown in figure 5, and the regional evaluation diagrams of the potential ecological risk index of the heavy metal of the sediment of 0-5cm, 5-10cm and 10-15cm are shown in figures 6-8.
Finally, for each water sampling point (P1 to P6), a nitrate nitrogen content change diagram, a nitrite nitrogen content change diagram, an ammonium nitrogen content change diagram, a phosphate content change diagram and an inorganic nitrogen content change diagram (as shown in fig. 9 to 14) of the water sampling point along with the change of the depth near the interface are calculated and drawn according to the detection result of each sample of the water sampling point.
(ii) S1, a judgment is made in accordance with fig. 2 to 14.
On one hand, the general trend that the average total nitrogen content and the average total phosphorus content of the bottom sediment change along with the different depths of the bottom sediment is not obvious, and the change ranges of the total nitrogen content and the total phosphorus content in the bottom sediment of different layers are wide. With the increase of the depth, the total nitrogen content of the bottom mud tends to be slightly reduced, and the total phosphorus content tends to be slightly increased. The heavy metal potential ecological risk index change trend of the bottom sediment is very obvious, and the surface layer bottom sediment is obviously higher than the deeper layer bottom sediment. And the judgment result is listed as a reference. Meanwhile, the depth range of the bottom sediment with the total nitrogen content being more than or equal to the total nitrogen content control value, the depth range of the bottom sediment with the total phosphorus content being more than or equal to the total phosphorus content control value and the depth range of the bottom sediment with the heavy metal potential ecological risk index being more than or equal to the heavy metal potential ecological risk index control value are all listed as reference basis.
On the other hand, the nitrogen concentration and the form in the sediment interstitial water and the overlying water are influenced by the microenvironment of the interface, the nitrate nitrogen concentration in the overlying water body above the interfaces of 6 sampling points is higher than that below the interface, and the ammonium nitrogen concentration below the interface is higher than that above the interface, because the water body above the interface is subjected to upper and lower water body exchange under the action of wind waves and the like to increase the oxygen content; the content of organic matters in the soil below the interface is high, and the microenvironment is in a reduction state. The polluted bottom mud has lower oxidation-reduction potential, nitrogen in the interstitial water mainly exists in the form of ammonium nitrogen, the nitrogen diffuses into the overlying water body under the action of concentration gradient, and the ammonium nitrogen is converted into nitrate nitrogen along with the increase of the dissolved oxygen content of the water body. Nitrite nitrogen in the water body is unstable and closely related to the microenvironment where the nitrite nitrogen is located, and mainly exists in a reduction state with lower oxidation-reduction potential.
Most of the monitored sampling points have a jumping trend of increasing or decreasing nitrate nitrogen and ammonium nitrogen at the interface of the gap water and the overlying water, the change range of the nitrite nitrogen is relatively small, the concentration of the nitrate nitrogen at the sampling point P5 gradually decreases in a straight line from the overlying water to the gap water, and the change at the interface is relatively small.
Inorganic nitrogen in the water mainly exists in the forms of nitrate nitrogen, nitrite nitrogen and ammonium nitrogen, the inorganic nitrogen concentration of interstitial water below interfaces of 6 sampling points exceeds the total nitrogen quality standard (2.0mg/L) of GB 3838-2002V water, the inorganic nitrogen concentration of overlying water bodies of the sampling points P1, P2 and P3 does not exceed 2.0mg/L, the overlying water body parts of the sampling points P4 and P5 exceed 2.0mg/L, the inorganic nitrogen concentration of overlying water bodies of the sampling points P6 exceeds 2.0mg/L, and the concentrations of different levels are almost not different.
The phosphate concentration of the overlying water body of 6 monitored sampling points exceeds the GB3838-2002 class III water body total phosphorus quality standard (0.05mg/L), the phosphate concentration of the overlying water body of the P1, P3, P5 and P6 sampling points does not exceed the GB3838-2002 class V water body total phosphorus quality standard (0.2mg/L), and the phosphate concentration of the overlying water body of the P2 sampling points and the P4 sampling points exceeds 0.2 mg/L.
In conclusion, the surface sediment near the interface is an important pollution source of nitrogen and phosphorus of the overlying water body, and the cleaning of the surface sediment from the lake has an important significance for reducing the pollution load of endogenous nitrogen and phosphorus. And the judgment result is listed as a reference.
And S2, because the thickness of the sediment at each sampling point is greater than or equal to the thickness control value, the sediment does not need to be removed.
And S3, evaluating each layer of sample after the columnar sediment of each sampling point is divided by combining a reference basis, and determining the dredging depth of the area represented by the sampling point, wherein the details are as described above. And attention is paid to eliminating the areas represented by the sampling points with shallow pollution smaller than the control value and deep pollution larger than the control value.
And S4, judging whether the sediment thickness of each sampling point is less than or equal to the dredging depth, and if so, taking the thickness control value as the dredging depth of the area represented by the sampling point.
Note: the area represented by the sampling point is an area obtained by expanding the sampling point by adopting a GIS space interpolation method under a preset interpolation parameter.
The distribution of the final dredging depth of this embodiment is shown in fig. 15, and the zone numbers and the corresponding dredging depths are shown in the following table.
| Numbering | Depth of dredging (cm) |
| 2-1 | 20 |
| 2-2 | 10 |
| 2-3 | 10 |
| 3-1 | 20 |
| 3-2 | 30 |
| 3-3 | 15 |
| 4-1 | 20 |
| 4-2 | 10 |
| 4-3 | 20 |
| 4-4 | 35 |
| 5-1 | 35 |
| 5-2 | 10 |
| 5-3 | 15 |
| 5-4 | 20 |
Example 4
This embodiment is the fourth step of the present invention, and the basic contents are as described above.
This example is based on example 3.
The following is a detailed example of the present embodiment.
And calculating the earthwork of the ecological dredging project of each region according to the known dredging area and dredging depth of each region, as shown in the following table.
The total earth volume of the ecological dredging engineering is 408.24 ten thousand meters3。
Compared with the previous 'ecological dredging overall implementation scheme' of the target water area, the invention has the advantages that the dredging earthwork is 544.7 ten thousand meters3Nuclear reduction to 408.24 km3Reduced by about 136.46 km3(corresponding to a reduction of about 25%); and the invention further refines and determines the ecological dredging depth of different areas according to the characteristics of the sediment at different areas, and improves the implementation precision of the ecological dredging project.
In addition to the above embodiments, the present invention may have other embodiments. All technical solutions formed by adopting equivalent substitutions or equivalent transformations fall within the protection scope of the claims of the present invention.
Claims (10)
1. A method for determining the dredging depth and the engineering quantity of an ecological dredging project is characterized by comprising the following steps:
firstly, setting sampling points in a preset ecological dredging range of a target water area and carrying out sediment investigation;
secondly, determining a total nitrogen content control value and a total phosphorus content control value of the sediment according to the total nitrogen content and the total phosphorus content of all sampling points of the columnar sediment samples and a water body monitoring report of a target water area by combining the existing data; determining a heavy metal potential ecological risk index control value of the sediment according to the heavy metal potential ecological risk indexes of all sampling point columnar sediment samples and by combining whether a target water area contains a resident drinking water source area or not; determining a thickness control value of the sediment according to the sediment thickness of all sampling points and by combining the vertical controllable precision of the dredging engineering construction;
thirdly, determining the dredging depth of the area where each sampling point is located according to the layered overall distribution characteristics of the bottom sediment pollutants of all the sampling points, and the vertical distribution characteristics of the total nitrogen content, the total phosphorus content and the heavy metal potential ecological risk index of the bottom sediment of each sampling point;
and step four, calculating the dredging engineering quantity according to the dredging depth of the region where each sampling point is located and the dredging area of the region where each sampling point is located.
2. The method for determining the dredging depth and the engineering quantity of the ecological dredging engineering according to claim 1, wherein in the first step, the setting density of the sampling points is more than 15/10 km2(ii) a Respectively collecting a columnar sediment sample at each sampling point, wherein the bottom end of the columnar sediment sample is at least 5cm of hard river sediment; the sediment survey comprises: firstly, dividing each columnar sediment sample from top to bottom according to a fixed length, then measuring the pollutant content of each layer of sample after each columnar sediment sample is divided, and calculating the pollutant content of each columnar sediment sample, wherein the pollutant content comprises total nitrogen content, total phosphorus content and heavy metal content; and measuring the thickness of the bottom mud.
3. The method for determining the dredging depth and the engineering quantity of the ecological dredging engineering according to claim 2, wherein the fixed length is 5-10 cm; after each column-shaped bottom mud is divided, the uppermost layer sample is closest to the water surface, and the lowermost layer sample is farthest from the water surface; the heavy metal comprises copper, zinc, lead, cadmium, nickel, total chromium, arsenic and mercury.
4. The method for determining the dredging depth and the dredging amount of the ecological dredging project as claimed in claim 2, wherein in the second step, the existing data includes papers or reports of the ecological dredging project of the lake sediment at home and abroad, and an assessment report of the total sediment pollution of the basin to which the target water area belongs; the total nitrogen content control value is selected from the lower limit value of the total nitrogen content of the bottom sludge corresponding to the water pollution degree in the existing data at the preset level, and the total phosphorus content control value is selected from the lower limit value of the total phosphorus content of the bottom sludge corresponding to the water pollution degree in the existing data at the preset level;
the potential ecological risk index of the heavy metal is calculated according to the following steps:
calculating the potential risk index of each heavy metal:
wherein the content of the first and second substances,
the pollution coefficient of the current heavy metal is obtained;
the content of the heavy metal in the bottom mud is measured in mg/kg;
mg/kg for calculating the required reference value;
is the potential risk index of the heavy metal;
is a toxicity response parameter of the heavy metal; i is the serial number of the heavy metal species;
and then calculating the potential ecological risk index of the heavy metal in the bottom mud:
wherein RI is the potential ecological risk index of heavy metal in the bottom sediment, n is the total amount of heavy metal species, i,
The same as before;
and taking the minimum value of the vertical controllable precision of the dredging engineering construction as the thickness control value of the bottom mud.
5. The method for determining the dredging depth and the engineering quantity of the ecological dredging project according to claim 4, wherein the preset grade is the most serious pollution grade when determining the total nitrogen content control value and the total phosphorus content control value of the bottom mud; in determining the heavy metal potential ecological risk index control value of the sediment, the heavy metal potential ecological risk index control value is selected from 150, 300, 600, 1200, and when the target water area contains the residential drinking water source, the heavy metal potential ecological risk index control value is 150 or 300.
6. The method for determining the dredging depth and the engineering quantity of the ecological dredging engineering according to claim 4, wherein in the third step, the specific process for obtaining the layered overall distribution characteristics of the bottom sediment pollutants of all sampling points comprises the following steps: calculating and drawing a total nitrogen content change diagram, a total phosphorus content change diagram and a heavy metal potential ecological risk index change diagram which change with depth in the sediment of the total region according to the pollutant content of each layer of samples after the columnar sediment of all sampling points is segmented;
the specific process for obtaining the vertical distribution characteristics of the total nitrogen content, the total phosphorus content and the potential ecological risk index of the heavy metal of the sediment at each sampling point comprises the following steps: and aiming at each sampling point, calculating and drawing a total nitrogen content change diagram, a total phosphorus content change diagram and a heavy metal potential ecological risk index change diagram of the sampling point along with the depth change according to the pollutant content of each layer of sample after the sampling point is divided by the columnar sediment.
7. The method for determining the dredging depth and the engineering quantity of the ecological dredging engineering according to claim 6, wherein the third step comprises the following steps:
s1, respectively judging whether the total nitrogen content, the total phosphorus content and the heavy metal potential ecological risk index of the sediment have a general trend changing along with different depths of the sediment according to a total nitrogen content change diagram, a total phosphorus content change diagram and a heavy metal potential ecological risk index change diagram in the sediment pollutant layered overall distribution characteristics of all sampling points, and respectively judging a sediment depth range of which the total nitrogen content is greater than or equal to a total nitrogen content control value, a sediment depth range of which the total phosphorus content is greater than or equal to a total phosphorus content control value and a sediment depth range of which the heavy metal potential ecological risk index is greater than or equal to a heavy metal potential ecological risk index control value; taking the judgment result as a reference;
s2, aiming at each sampling point, judging whether the sediment thickness of the sampling point is smaller than a thickness control value, if so, removing the area represented by the sampling point from a preset ecological dredging range;
s3, evaluating each layer of sample after the columnar sediment at each sampling point is divided, namely: in the vertical distribution characteristics of the total nitrogen content, the total phosphorus content and the heavy metal potential ecological risk index of the sediment at the sampling point, determining a sediment depth horizon with the total nitrogen content greater than or equal to a total nitrogen content control value according to a total nitrogen content change diagram, determining a sediment depth horizon with the total phosphorus content greater than or equal to a total phosphorus content control value according to a total phosphorus content change diagram, and determining a sediment depth horizon with the heavy metal potential ecological risk index greater than or equal to a heavy metal potential ecological risk index control value according to a heavy metal potential ecological risk index change diagram; the bottom sediment depth layer refers to the depth range of the bottom sediment of each layer of samples after the columnar bottom sediment is divided; selecting the deepest sediment depth from all the sediment depth horizons as the desilting depth of the area represented by the sampling point;
s4, judging whether the sediment thickness of each sampling point is less than or equal to the dredging depth, if so, taking the thickness control value as the dredging depth of the area represented by the sampling point;
the area represented by the sampling points refers to an area obtained by expanding the sampling points by adopting a GIS space interpolation method under the preset interpolation parameters.
8. The method for determining the dredging depth and the engineering quantity of the ecological dredging project according to claim 7, wherein in S3, if the pollutant indexes of the shallow sediment of the sampling point are all smaller than the corresponding pollutant index control values, and the pollutant indexes of the deep sediment of the sampling point are all larger than or equal to the corresponding pollutant index control values, the area represented by the sampling point is removed from the preset ecological dredging range; the pollutant indexes comprise total nitrogen content, total phosphorus content and heavy metal potential ecological risk index;
taking the maximum sediment depth of the resuspension of the surface sediment of the target water area caused by hydrodynamic conditions as a depth limit value; the shallow sediment refers to a columnar sediment segmented sample with the depth less than or equal to a depth threshold value; the deep bed mud refers to a sample obtained after the column-shaped bed mud with the depth larger than the depth threshold value is segmented.
9. The method for determining the dredging depth and the engineering quantity of the ecological dredging engineering according to claim 7, wherein the first step further comprises the following steps: placing a balanced type gap water sampling device as a water sampling point at a preset site in a preset ecological dredging range of a target water area, and detecting the nitrate nitrogen content, the ammonium nitrogen content, the nitrite nitrogen content and the phosphate content of each sample after sampling;
the third step further comprises: aiming at each water sampling point, calculating and drawing a nitrate nitrogen content change diagram, a nitrite nitrogen content change diagram, an ammonium nitrogen content change diagram, a phosphate content change diagram and an inorganic nitrogen content change diagram of the water sampling point along with the change of the depth near the interface according to the detection result of each sample of the water sampling point;
s1 of the third step further includes: and judging whether the sediment near the interface is a pollution source of the overlying water nitrogen phosphorus pollution or not according to the content change graphs of the water sampling points, and listing the judgment result as a reference.
10. The method for determining the dredging depth and the engineering quantity of the ecological dredging engineering according to claim 9, wherein the balanced type gap water sampling device is vertically arranged and longitudinally spans a bottom sediment gap water-overlying water interface after being arranged; the sampling precision of the balanced type gap water sampling device is 1.25 +/-0.05 cm; and the balanced interstitial water sampling device is balanced for 10-15 days after being placed, and a sample is taken out and detected.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110642548.6A CN113504352B (en) | 2021-06-09 | 2021-06-09 | Method for determining dredging depth and engineering quantity of ecological dredging engineering |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110642548.6A CN113504352B (en) | 2021-06-09 | 2021-06-09 | Method for determining dredging depth and engineering quantity of ecological dredging engineering |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN113504352A true CN113504352A (en) | 2021-10-15 |
| CN113504352B CN113504352B (en) | 2024-02-09 |
Family
ID=78009752
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202110642548.6A Active CN113504352B (en) | 2021-06-09 | 2021-06-09 | Method for determining dredging depth and engineering quantity of ecological dredging engineering |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN113504352B (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114877796A (en) * | 2021-12-09 | 2022-08-09 | 长沙理工大学 | Rapid determination method for sludge thickness based on oxidation-reduction potential |
| NL2032787B1 (en) * | 2022-08-18 | 2024-02-27 | Northwest Inst Plateau Bio Cas | Method for evaluating heavy metal contamination for different land use types |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102831328A (en) * | 2012-09-13 | 2012-12-19 | 中国环境科学研究院 | Method for determining environmental-protection dredging range based on water pollution bottom mud identification and evaluation |
| CN102854221A (en) * | 2012-10-15 | 2013-01-02 | 中国科学院南京地理与湖泊研究所 | In-situ measurement device and method for sediment breathing and nitrogen endogenous release |
| CN110258439A (en) * | 2019-05-31 | 2019-09-20 | 南京国兴环保产业研究院有限公司 | A kind of combined pollutant multiple target environmental dredging method based on 4R theory |
| CN110726684A (en) * | 2019-10-22 | 2020-01-24 | 中国计量大学 | Method for determining dredging depth of river sediment based on polycyclic aromatic hydrocarbon and heavy metal pollution |
-
2021
- 2021-06-09 CN CN202110642548.6A patent/CN113504352B/en active Active
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102831328A (en) * | 2012-09-13 | 2012-12-19 | 中国环境科学研究院 | Method for determining environmental-protection dredging range based on water pollution bottom mud identification and evaluation |
| CN102854221A (en) * | 2012-10-15 | 2013-01-02 | 中国科学院南京地理与湖泊研究所 | In-situ measurement device and method for sediment breathing and nitrogen endogenous release |
| CN110258439A (en) * | 2019-05-31 | 2019-09-20 | 南京国兴环保产业研究院有限公司 | A kind of combined pollutant multiple target environmental dredging method based on 4R theory |
| CN110726684A (en) * | 2019-10-22 | 2020-01-24 | 中国计量大学 | Method for determining dredging depth of river sediment based on polycyclic aromatic hydrocarbon and heavy metal pollution |
Non-Patent Citations (6)
| Title |
|---|
| 刘志刚: "南淝河内源污染氮、磷释放规律及生态清淤模式", 《资源节约与环保》 * |
| 张亚等: "遵义市中心城区河道底泥污染评价及底泥清淤方案", 《水电能源科学》 * |
| 文帅龙等: "于桥水库沉积物-水界面氮磷剖面特征及交换通量", 《环境科学》 * |
| 王东升等: "论浅水湖泊中的水固交错带与科学清淤规划――以雄安新区白洋淀为例", 《环境科学学报》 * |
| 范成新等: "湖泊底泥环保疏浚决策研究进展与展望", 《湖泊科学》 * |
| 陈国柱等: "浅析长诏水库生态清淤的范围和深度", 《浙江水利科技》 * |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114877796A (en) * | 2021-12-09 | 2022-08-09 | 长沙理工大学 | Rapid determination method for sludge thickness based on oxidation-reduction potential |
| CN114877796B (en) * | 2021-12-09 | 2024-01-12 | 长沙理工大学 | Sludge thickness rapid determination method based on oxidation-reduction potential |
| NL2032787B1 (en) * | 2022-08-18 | 2024-02-27 | Northwest Inst Plateau Bio Cas | Method for evaluating heavy metal contamination for different land use types |
Also Published As
| Publication number | Publication date |
|---|---|
| CN113504352B (en) | 2024-02-09 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Zhao et al. | Study of heavy metal pollution, ecological risk and source apportionment in the surface water and sediments of the Jiangsu coastal region, China: a case study of the Sheyang Estuary | |
| Romano et al. | The impact of the Bagnoli industrial site (Naples, Italy) on sea-bottom environment. Chemical and textural features of sediments and the related response of benthic foraminifera | |
| Mao et al. | Deciphering spatial pattern of groundwater chemistry and nitrogen pollution in Poyang Lake Basin (eastern China) using self-organizing map and multivariate statistics | |
| CN101266235A (en) | Polluted water body deposit environment-friendly dredging depth determination method | |
| CN113504352B (en) | Method for determining dredging depth and engineering quantity of ecological dredging engineering | |
| Ni et al. | Historical accumulation of N and P and sources of organic matter and N in sediment in an agricultural reservoir in Northern China | |
| Guo et al. | Physicochemical parameters and phytoplankton as indicators of the aquatic environment in karstic springs of South China | |
| Bian et al. | Hydro-geochemical characteristics and health risk evaluation of nitrate in groundwater | |
| Dizaji et al. | Assessing pollution risk in Ardabil aquifer groundwater of Iran with arsenic and nitrate using the SINTACS model | |
| CN113406025A (en) | Method for determining dredging range of ecological dredging project of water area | |
| Li et al. | Spatial-temporal variation, ecological risk, and source identification of nutrients and heavy metals in sediments in the peri-urban riverine system | |
| Habous Nazzal et al. | Multivariate statistical analysis of urban soil contamination by heavy metals at selected industrial locations in the Greater Toronto area, Canada | |
| Zamorano et al. | Spatiotemporal changes in soil phosphorus characteristics in a submerged aquatic vegetation-dominated treatment wetland | |
| Mitraki et al. | Lake Koronia, Greece: Shift from autotrophy to heterotrophy with cultural eutrophication and progressive water-level reduction | |
| Hu et al. | An assessment of spatial distribution and source identification of five toxic heavy metals in Nanjing, China | |
| Meng et al. | Accumulation, sources and pollution of heavy metals in the sediments of coastal tidal flats in the North Jiangsu Radial Sand Ridges, China | |
| White et al. | Groundwater-surface water interaction in the Waimakariri River, New Zealand, and groundwater outflow from the river bed | |
| Liu et al. | Spatial Distribution and Influence Analysis of Soil Heavy Metals in a Hilly Region of Sichuan Basin. | |
| Wang et al. | Integrated assessment of trace elements contamination in sediments of a typical aquaculture bay in China: Ecological toxicity, sources and spatiotemporal variation | |
| Deng et al. | Characteristics of Water Pollution and Evaluation of Water Quality in Subsidence Water Bodies in Huainan Coal Mining Areas, China | |
| Wu et al. | Pollution levels and toxicity risks of heavy metals in different reed wetland soils following channel diversion in the Yellow River Delta | |
| CN110658327B (en) | River basin surface source heavy metal silt enrichment ratio calculation method based on sediment analysis | |
| Yang et al. | Characterization and Risk Assessment of Nutrient and Heavy Metal Pollution in Surface Sediments of Representative Lakes in Yangxin County, China | |
| Perner | Influence of sediment characteristics and oxygen demand on winter hypoxia in backwater lakes of the Upper Mississippi River | |
| Li et al. | Speciation and spatial distribution of nitrogen in surface sediments of in Ming Lake |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |