CN104458518B - Method for monitoring and qualitatively and quantitatively analyzing sediments in small-caliber sewer line - Google Patents

Abstract

The invention discloses a method for monitoring and qualitatively and quantitatively analyzing sediments in a small-caliber sewer line. The principle of the method is that the sediments mainly come from SS in water in the absence of microbes. Based on the principle, the method comprises the following steps: selecting a small-caliber pipeline with short distance, periodically sampling from an inspection well I connected with the pipeline, simultaneously sampling an inspection well II according to the time when water flow reaches the inspection well II, and calculating the SS sedimentation rate between the two inspection wells so as to judge the sedimentation condition of the sediments; measuring the conventional indexes of the sample, and finding obvious degradation according to the change contrast of different indexes, thereby determining the material compositions contained in the sediments; measuring the particle size distribution in a water sample, and judging the particle size composition of the sediments in the small-caliber sewer line according to the particle size distribution change condition; and finally, obtaining the accumulated amount of the sediments between the inspection well I and the inspection well II according to a formula. The method disclosed by the invention is applied to research on sediments in shunt/convergence-free pipe sections with the pipe diameter of 300mm below.

Description

A kind of to the monitoring of deposit in pipe with small pipe diameter sewage conduct and qualitative and quantitative analysis method

Technical field

The invention belongs to technical field of sewage, particularly to a kind of to the monitoring of deposit in pipe with small pipe diameter sewage conduct And qualitative and quantitative analysis method.

Background technology

Urban discharging pipeline is the important component part of sewerage system, during sewage transport due to sewage or Rainwater enters multiformity and the randomness of pipeline flow change of the particulate matter type of pipeline, and urban discharging pipeline is nearly all deposited In accumulation of pollutants phenomenon in various degree.But above-mentioned deposit not only results in pipeline water delivery ability and declines, and along with The uneven change of flow, deposit is washed release, causes pipeline pollutant burden to increase, the water of serious threat receiving water body Environment.Thus the character of research deposit and deposition tool are of great significance.

But the type of municipal sewage pipe network is many, the water project situation such as caliber, the gradient is different, and along with hydraulics Change deposit also can accordingly increase or reduce.Thus the study of the monitoring method for pipeline deposit is very few, only limits to Deposition characteristics analysis in Large Diameter Pipeline pipeline section is monitored with qualitative, quantitative.

Deposit monitoring for the sewage pipeline section of Large Diameter Pipeline at present is analyzed, and also simply uses pipe robot to go deep into pipeline It is sampled, and on connected watch-dog, generates pipe interior deposition by the Sonar Probe being installed in robot Thing and the real time imaging of pipeline.And small-caliber pipeline diameter is less, and the flow velocity depth of water is all little, and this not only directly results in robot Pipeline cannot be entered smoothly be sampled and Sonar Probe cannot be totally submerged below horizontal plane.Thus cannot take out Small-caliber pipeline deposit carries out character analysis, also cannot obtain the deposition conditions of deposit.

Therefore this patent is for monitoring the content of pipe with small pipe diameter deposit, probes into sewage network deposit character, all has ten Divide important meaning.

Summary of the invention

In order to overcome the shortcoming of above-mentioned prior art, the present invention provides a kind of to the prison of deposit in pipe with small pipe diameter sewage conduct Survey and qualitative and quantitative analysis method, the perfect monitoring to municipal sewage pipe network deposit and analysis and research, reach to improve city The purpose that the monitoring of sewage network deposit is analyzed.

To achieve these goals, the technical solution used in the present invention is:

The pipeline 3 selecting short distance, nothing to conflux and shunt, periodically samples from the inspection shaft 1 connecting pipeline 3, makes simultaneously Record flow and the flow velocity of current at this with effusion meter, obtain current arrival according to spacing and flow velocity and be positioned at inspection shaft 1 downstream Time of inspection shaft 22, and sample at inspection shaft 22 in this time.Then according to formulaCalculate SS to exist The rate of settling therebetween, wherein D is the rate of settling, unit mg/L s；SS₁It is SS measured value, unit mg/L at inspection shaft 1； SS₂It is SS measured value, unit mg/L at inspection shaft 22；S is the spacing between inspection shaft 1 and inspection shaft 22, unit m；V is Current flow velocity between inspection shaft 1 and inspection shaft 22, unit m/s；Deposit situation is obtained according to the described rate of settling, The conventional index simultaneously measuring current is distributed with particle diameter, thus deposit in pipeline carries out qualitative analysis and judgement, and according to Formula M_Deposition=(SS₁-SS₂) Q Δ t obtains deposit cumulant M between inspection shaft 1 and inspection shaft 22_Deposition, wherein Q For the average discharge in pipeline, Δ t is the interval time sampled from inspection shaft 1 and inspection shaft 22.

Secondly, the water quality conventional index in inspection shaft 1 and inspection shaft 22 sample is measured.Conventional index includes total phosphorus (TP), total nitrogen (TN), ammonia nitrogen (NH₄ ⁺-N), nitrate nitrogen (NO₃-N), COD (COD), These parameters both can pass through Hash Reagent is measured, it is also possible to measured by national standard method.By the change contrast of different indexs is found that notable degraded is (average Degraded about 30%) specific targets, thus obtain the key component composition of deposit therebetween.

Then, use granularmetric analysis instrument or sieve method to measure change of size, go out not based on change of size status analysis With in the time period under different in flow rate flow sediment grain size composition.

In the present invention, based on to inspection shaft 1 and the SS of inspection shaft 22 periodic measurement, flow velocity v and flow Q, it is depicted as horizontal stroke Axle is the curve of time, and uses method of least square that inspection shaft 1 and the SS of inspection shaft 22, flow velocity v and flow Q are carried out public affairs Formula matching.The caliber of described pipeline 3 is at below 300mm and without shunting and the effect of confluxing.

Compared with prior art, the present invention is applicable to the caliber research at the pipeline section deposit of below 300mm, by institute The monitoring calculation of a series of indexs such as the conventional index of water sampling, SS difference and particle diameter distribution, obtains deposition in studied pipeline section The character of thing and the general status of deposition characteristics, pollutant conversion wherein is had deeper into understanding.This method avoids The adverse effect that pipe with small pipe diameter deposit is studied by original method, the perfect scope to deposit research, by indirect mode pair The character of pipe with small pipe diameter deposit carries out probing into of science.

Accompanying drawing explanation

Fig. 1 is to use the schematic diagram of water quality SS change in marine sediment Wen Dehua grade criteria for classification research pipeline.

Fig. 2 is sampling principle figure of the present invention.

Fig. 3 is the median particle diameter scattergram of the embodiment of the present invention 1.

Fig. 4 is five conventional index concentration map of the embodiment of the present invention, and Fig. 4 a is TN concentration, and Fig. 4 b is NH₄ ⁺-N concentration, figure 4c is NO₃-N concentration, Fig. 4 d is COD concentration, and Fig. 4 e is TP concentration.

Fig. 5 is the median particle diameter scattergram of the embodiment of the present invention 2.

Detailed description of the invention

Embodiments of the present invention are described in detail below in conjunction with the accompanying drawings with embodiment.

The principle of the invention is: under conditions of not considering microbial action, deposits during in pipe network, the variable quantity of SS is pipeline The variable quantity of thing, as shown in formula (1).

M_Deposition=(SS₁-SS₂)·Q·Δt (1)

Marine sediment Wen Dehua grade criteria for classification is used to have studied water quality SS in pipeline based on the above-mentioned principle present invention Change (as shown in Figure 1), show that the particulate matter of D<4 μm is easiest to wash away, and D>63 μm particulate matter starts deposition.And particle diameter is the most heavy Long-pending the best, particle diameter D > 125 μm particulate matter is easiest to deposition.And other researchs show, in pipeline, deposit is gravitational settling, flow velocity The biggest, the poorest scouring effect of effect of settling is the best.

According to above-mentioned principle and Sediment property, the present invention is applicable to:

1) do not conflux and shunt conduit；

2) pipeline that flowing time is short and pipeline section is less.

Thus, as in figure 2 it is shown, first this method selects to be suitable for the pipeline of above-mentioned condition in implementation process.And selector The inspection shaft 1 of conjunction condition and inspection shaft 22.Periodically inspection shaft 1 and inspection shaft 22 are sampled and flowed on this basis Amount flow monitoring, its sampling rule is: inspection shaft 22 sampling must carry out and be spaced current arriving after inspection shaft 1 is sampled The time of inspection shaft 22.After sampling, according to inspection shaft 1 and the SS of inspection shaft 22, calculate deposition in each time period Thing sedimentation rate, the sedimentation state of this result reflection deposit.Its formula is:

$D=\frac{{\mathrm{SS}}_1-{\mathrm{SS}}_2}{l/v}---\left(2\right)$

In formula: the D rate of settling (mg/L s)

SS₁SS measured value (mg/L) at inspection shaft 1

SS₂SS measured value (mg/L) at inspection shaft 22

L inspection shaft spacing (m)

The instant flow velocity of v (m/s)

Then, based on above-mentioned gathered sample, inspection shaft 1 in pipeline 3 and inspection shaft 22 are carried out conventional water quality index Monitoring.Conventional index includes total phosphorus (TP), total nitrogen (TN), ammonia nitrogen (NH₄ ⁺-N), nitrate nitrogen (NO₃-N), COD (COD), These parameters both can be measured by Hash reagent, it is also possible to is measured by national standard method.By the change to different indexs Change contrast and find the specific targets of notable degraded (average degraded about 30%), thus the key component obtaining deposit therebetween becomes Point.

It follows that use granularmetric analysis instrument or sieve method to measure change of size, go out based on change of size status analysis In different time sections, under different in flow rate flow, sediment grain size forms.

Finally, the content of deposit in small-caliber pipeline is measured.In this method, the deposits amount drawn based on principle Formula is:

$M\left(t\right)={\&Integral;}_{t_0}^{t}Q\left(t\right){\mathrm{SS}}_1\left(t\right)dt-{\&Integral;}_{t_0}^{t}Q\left(t\right){\mathrm{SS}}_{2}t+\frac{l}{V\left(t\right)}dt---\left(3\right)$

t₀Being the termination time for time of preliminary examination, t, Q (t) is flow fitting function, SS₁T () is that the SS of one 1, inspection shaft intends Close function, SS₂(t) be the SS fitting function of 22, inspection shaft, V (t) be flow velocity fitting function.

Its concrete method for solving is as follows:

1) inspection shaft 1, the SS of inspection shaft 22, flow velocity v and flow Q being carried out periodic measurement, being depicted as transverse axis is the time Curve.

2) use method of least square that inspection shaft 1, the SS of inspection shaft 22, flow velocity v and flow Q curve are carried out formula plan Close, and the R after guarantee period matching²Meet relevant regulatory requirements.

3) fit equation is brought in corresponding equation solves.Complicated formulas can use computer integration (to seek at random Point method, rectangle solving method, definition method etc.), integral result is pipeline deposits amount.

It is pointed out that formula (3) has following 2 special cases, can directly simplify calculating process under this special case:

1. the sedimentation rate of deposit under flow velocity, stability of flow state

In this condition, flow velocity keeps stable, and now the deposition of deposit can be expressed as:

$M\left(t\right)=Q{\&Integral;}_{t_0}^t\&lsqb;{\mathrm{SS}}_1\left(t\right)-{\mathrm{SS}}_2(t+\frac{l}{v})\&rsqb;dt---\left(4\right)$

When apart from the most in short-term, in certain range of errorBeing negligible, now formula (4) can be further It is reduced to:

$M\left(t\right)=Q{\&Integral;}_{t_0}^t\&lsqb;{\mathrm{SS}}_1\left(t\right)-{\mathrm{SS}}_2\left(t\right)\&rsqb;dt---\left(5\right)$

Formula (5) shows at constant flow, and the pipeline that distance is shorter, deposition is curve SS₁With curve SS₂The face surrounded The long-pending product with flow Q.

2. without the deposition conditions in the pipe with small pipe diameter pole pipeline short time that confluxes

Pole pipe with small pipe diameter is predominantly located at the initiating terminal of drainage pipeline, and the situation of change of water quality, the water yield and flow velocity mainly depends on In factors such as Land in Regional Land purposes, production technology, living habit and rainfalls.Therefore in error allowed band, can be by SS, stream Amount Q and flow velocity v is considered as piecewise function, thus formula (3) can be reduced to:

$M\left(t\right)=\underset{i=1}{\overset{n}{\&Sigma;}}{Q}_i\&lsqb;{\mathrm{SS}}_{1,i}\left(t_i\right)-{\mathrm{SS}}_{2,i}(t_i+\frac{l}{V_i})\&rsqb;*t_i---\left(6\right)$

In formula, n is monitoring time hop count, Q_iIt is average discharge in i-th section of interior conduit, SS_{1, i}(t_i) it is inspection shaft in i-th section The SS fitting function of one 1, SS_{2, i}(t_i) be i-th section in the SS fitting function of 22, inspection shaft, l is inspection shaft 1 and checks The spacing of well 22, V_iIt is mean flow rate in the i-th time period, t_iIt it was the i-th duration time period.

The monitoring method that the present invention relates to the most easily realizes with experimental apparatus, such as below embodiment.

Embodiment 1:

Choosing section, eastern suburb, the Xi'an one long pipeline section of qualified 110m the most on the spot, caliber is 300mm, therebetween without converging Stream.Search time section is the deposits situation of 8:00-16:00；

2. pair institute's water sampling carries out total phosphorus (TP), total nitrogen (TN), ammonia nitrogen (NH₄ ⁺-N), nitrate nitrogen (NO₃-N), COD (COD) monitoring calculation of conventional index such as.Conventional index utilizes Hash reagent to be measured；The mensuration of SS difference utilizes to dry and claims Weight method be measured, utilize below equation calculate the SS rate of settling betwixt:

$D=\frac{{\mathrm{SS}}_1-{\mathrm{SS}}_2}{l/v}$

The D rate of settling (mg/L s)

SS₁SS measured value (mg/L) at inspection shaft 1

SS₂SS measured value (mg/L) at inspection shaft 22

L inspection shaft spacing (m)

The instant flow velocity of v (m/s)

3. the Particle Size Analyzer of the available specialty of particle diameter distribution is measured, and uses median particle diameter D₅₀Relation between expression, As shown in Figure 3, it is found that the float particle diameter of different time two sample point has declined, and median particle diameter generally reduces, just The D during beginning₅₀Reduction amount reaches 23.1%, but along with the increase effect of flow velocity gradually weakens.

4. changing due to this pipeline water sample water quality, the water yield and flow velocity saltatory the most in time, hopping time is about 2h, Change not notable in a certain amount of time, belong to special case 2.Therefore carried out the sampling of a group every 2 hours from 8:00 to 16:00；

5. by Δ SS function, Q function and V function according to time slice, as shown in table 1, and by this function according to respective area Section is put in formula (6), and result is listed in table 1:

$M\left(t\right)=\underset{i=1}{\overset{n}{\&Sigma;}}{Q}_i\&lsqb;{\mathrm{SS}}_{1,i}\left(t_i\right)-{\mathrm{SS}}_{2,i}(t_i+\frac{l}{V_i})\&rsqb;*t_i$

Table 1 piecewise function and result of calculation

6. from table 1 and the data analysis of Fig. 2, Fig. 4, suspended substance sedimentation speed and flow velocity in pipeline in pipe with small pipe diameter In inverse correlation, the biggest particle diameter float has precedence over small particle float and settles in pipeline, and deposition effect can be along with flow The increase of flow velocity weakens.In addition to TN, it is the least that other index concentration reduces degree, but the NH when 12:00 concentration is bigger₄ ⁺、NO₃ There is obvious degradation, respectively 33.4% and 58.6%, cause mainly due to suspended substance sedimentation；Other times are likely to be due to it Degraded depends on other processes of biological decomposition or physical chemistry etc., so effect inconspicuous；The concentration of TN has bright Aobvious reduction, average degradation rate is 0.034mg/L s, reaches 34.6%, it was demonstrated that deposit N content is higher.Thus it can also be seen that dense When spending higher, suspended substance sedimentation effect becomes apparent from.And it was from the amount of the being deposited as 34814.42mg of 6 o'clock to 16 o'clock.

Embodiment 2:

1. the qualified 80m in section, Xi'an one long pipeline, caliber 300mm, period do not confluxes, periodically investigates water quality The water yield and deposit.Search time is 0:00～10:00, and result is listed in table 2；

2. pair institute's water sampling carries out total phosphorus (TP), total nitrogen (TN), ammonia nitrogen (NH₄ ⁺-N), nitrate nitrogen (NO₃-N), COD Etc. (COD) monitoring calculation of conventional index, is listed in table 3.Conventional index utilizes Hash reagent to be measured；The mensuration of SS difference Utilize and dry the method weighed and be measured, utilize below equation to calculate the SS rate of settling betwixt:

$D=\frac{{\mathrm{SS}}_1-{\mathrm{SS}}_2}{l/v}$

The D rate of settling (mg/L s)

SS₁SS measured value (mg/L) at inspection shaft 1

SS₂SS measured value (mg/L) at inspection shaft 22

L inspection shaft spacing (m)

The instant flow velocity of v (m/s)

3. the Particle Size Analyzer of the available specialty of particle diameter distribution is measured, and uses median particle diameter D₅₀Relation between expression, As shown in Figure 5, it is found that the float particle diameter of different time two sample point has declined, and median particle diameter generally reduces, insult Morning 12 middle D₅₀Reduction amount reaches minimum 23%, but along with the increase effect of flow velocity gradually weakens.

4. taking a sample to research discovery, in this pipeline, to belong to flowing change continuously more notable for flow, flow velocity and SS, therefore needs to intend Close out matching song simulation curve.Within every 2 hours, taking one group of sample, its index is as shown in table 2, and the fit equation of each curve is:

SS₁(t)=0.1706t⁵-4.3542t⁴+37.901t³-124.21t²+101.92t+130

R²=1.000

SS₂(t)=0.1549t⁵-3.8177t⁴+31.922t³-99.229t²+68.333t+120

R²=1.000

Q (t)=0.1707t⁴+2.9172t³-12.258t²+3.9303t+48.622

R²=1.000

V (t)=-0.006t⁴+0.011t³-0.0502t²+0.0325t+0.248

R²=0.998

5. above-mentioned fitting formula is brought into formula (3), and uses and seek an algorithm at random formula (3) is carried out 0:00～10: The integral operation of 00.In conjunction with table 2, table 3 and Fig. 5 analysis, in pipe with small pipe diameter, suspended substance sedimentation speed and flow velocity in pipeline are in instead Relevant, the biggest particle diameter float has precedence over small particle float and settles in pipeline, and deposition effect can be along with flow velocity Increase weaken.In addition to COD, it is the least that other index concentration reduces degree, it was demonstrated that deposit COD content is higher.The most also can Find out that when concentration is higher, suspended substance sedimentation effect becomes apparent from.And SS analyzes and show that it from the deposition of 6 o'clock to 16 o'clock is 33769.35mg。

Table 2 Monitoring Data

Table 3 water quality parameter (mg/L)

Claims (6)

1. one kind to the monitoring of deposit in pipe with small pipe diameter sewage conduct and qualitative and quantitative analysis method, it is characterised in that select short The pipeline (3) that distance, nothing are confluxed and shunted, periodically samples from the inspection shaft one (1) connecting pipeline (3), uses effusion meter simultaneously Record flow and the flow velocity of current at this, obtain current arrival according to spacing and flow velocity and be positioned at the inspection in inspection shaft one (1) downstream The time of well two (2), and sample at inspection shaft two (2) in this time；Then according to formulaCalculate SS at it Between the rate of settling, wherein D is the rate of settling, unit mg/L s；SS₁It is inspection shaft one (1) place SS measured value, unit mg/L； SS₂It is inspection shaft two (2) place SS measured value, unit mg/L；L is the spacing between inspection shaft one (1) and inspection shaft two (2), single Position m；V is current flow velocitys between inspection shaft one (1) and inspection shaft two (2), unit m/s；Obtain according to the described rate of settling Deposit situation, measures the conventional index of current simultaneously and is distributed with particle diameter, thus deposit in pipeline is carried out qualitative analysis with Judge, and according to formula M_Deposition=(SS₁-SS₂) Q Δ t obtains the deposit between inspection shaft one (1) and inspection shaft two (2) Cumulant M_Deposition, average discharge during wherein Q is pipeline, Δ t is when the interval that inspection shaft one (1) and inspection shaft two (2) sample Between.

The most according to claim 1 to the monitoring of deposit in pipe with small pipe diameter sewage conduct and qualitative and quantitative analysis method, its Being characterised by, described conventional index includes total phosphorus TP, total nitrogen TN, ammonia nitrogen NH₄ ⁺-N, nitrate nitrogen NO₃-N, COD COD, pass through Hash reagent or national standard method are measured.

The most according to claim 1 to the monitoring of deposit in pipe with small pipe diameter sewage conduct and qualitative and quantitative analysis method, its Being characterised by, the method that described SS is weighed by drying measures, and the distribution of described particle diameter utilizes Particle Size Analyzer or sieve method It is measured.

The most according to claim 1 monitoring and the qualitative, quantitative of deposit in pipe with small pipe diameter sewage conduct are divided Analysis method, it is characterised in that described M_DepositionAccounting equation after calculating formula utilizes calculus to solve is:Wherein, t₀Being the termination time for time of preliminary examination, t, Q (t) is flow matching letter Number, SS₁(t) be inspection shaft one (1) put SS fitting function, SS₂T () is that the SS fitting function put of inspection shaft two (2), V (t) are Flow velocity fitting function, l are the distance that inspection shaft one is put to inspection shaft two (2) at (1) o'clock, when in pipeline, water quality and quantity change is constant Time,I.e. deposition is changed to curve SS₁With curve SS₂The area surrounded is taken advantage of with Q's Long-pending.

The most according to claim 1 to the monitoring of deposit in pipe with small pipe diameter sewage conduct and qualitative, quantitative Analysis method, it is characterised in that pipe with small pipe diameter pole draining pipeline section deposit content computing formula is without confluxingWherein n is monitoring time hop count, Q_iIt it is mean flow in i-th section of interior conduit Amount, SS_{1, i}(t_i) be i-th section in the SS fitting function put of inspection shaft one (1), SS_{2, i}(t_i) be i-th section in inspection shaft two (2) put SS fitting function, l is inspection shaft one (1) and the spacing of inspection shaft two (2), V_iIt is mean flow rate in the i-th time period, t_iIt is i-th Duration time period.

The most according to claim 1 to the monitoring of deposit in pipe with small pipe diameter sewage conduct and qualitative and quantitative analysis method, its Being characterised by, the caliber of described pipeline (3) is at below 300mm and without shunting and the effect of confluxing.