CN113946142B

CN113946142B - Automatic control treatment method for sludge water and sludge dewatering process of tap water plant

Info

Publication number: CN113946142B
Application number: CN202110688455.7A
Authority: CN
Inventors: 郭志刚; 贾建青; 陈玲; 邓雷; 郑莉; 翟作卫; 谢世钊; 郭可莹; 刘晖; 魏琳
Original assignee: Henan Zhongxia Water Co ltd
Current assignee: Henan Zhongxia Water Co ltd
Filing date: 2021-06-19
Publication date: 2024-07-05
Anticipated expiration: 2041-06-19

Abstract

The invention discloses a self-control treatment method of a mud water and sludge dewatering process of a tap water plant, which is used for treating mud water and sludge concentration of the tap water plant and is characterized by comprising the following operation steps of: s1: obtaining a precipitation condition through analysis of sludge properties and a static precipitation test; s2: determining the most suitable type and dosage of the medicament through experiments on the medicament; s3: the high-efficiency sedimentation and concentration tank is adopted, and the high-efficiency sedimentation and concentration tank is combined with inclined plate sedimentation, so that the solid content of sludge in the bottom concentration area is improved, and the sludge directly enters a dehydration process to improve the concentration efficiency; s4: the floating mud-water separation device is used for reducing the amount of the sludge water entering the subsequent equipment. By the mode, compared with the traditional sludge water treatment process, the optimized process and equipment have the advantages that the occupied area of a water works is reduced, the engineering investment is reduced, the energy consumption is saved, and the water resource recovery and the conservation and utilization are realized through the research on the treatment process and the technical equipment.

Description

Automatic control treatment method for sludge water and sludge dewatering process of tap water plant

Technical Field

The invention relates to a sludge water treatment process of a tap water plant, belongs to the field of environment-friendly water treatment, and particularly relates to a self-control treatment method of a sludge water treatment process of a tap water plant.

Background

Water resources are an important and irreplaceable resource for human beings, are indispensable in the survival and development processes of the human beings, and in the research of sludge water treatment and sludge disposal of urban waterworks, we find the following problems,

Urban water works sludge water treatment current situation

Most of urban water sources of water works are taken from surface water bodies such as rivers and lakes, sludge water generated by the water works mainly comes from sludge water of a sedimentation tank and backwash water of a filter tank, and sludge in the sludge water consists of suspended impurities such as muddy sand, humus and algae in raw water, coagulant and coagulant aid added into the water works, wherein the sludge water is mainly composed of the two parts. Most urban water works in China do not treat the mud water discharged from the water works, the mud water is directly discharged into nearby natural water bodies, certain pollution is caused to the environment, the harm caused by the mud water discharged from the water works is more serious along with the deterioration of the environment, in addition, the mud water discharged from the water works generally accounts for 4% -7% of the total water purifying amount of the water works, and the direct discharge also causes the waste of water resources and the increase of energy consumption.

The work of sludge water treatment and sludge disposal in urban waterworks in China was formally mentioned to the agenda in the 80 s of the 20 th century. In 1988, xie Zhiping, which was written in wastewater and sludge treatment in Water supply plants, was integrated with the data of countries such as the United states, japan, soviet Union, england, france, etc. The book systematically describes the types, the amounts and the components of sewage and sludge of a water purification plant, the treatment methods of the sewage and the sludge, the structures, the designs and the management of various structures, the recovery of flocculating agents in the sludge, the final treatment and the utilization of dehydrated mud cakes and the like, and has higher reference value for the treatment of wastewater produced by the water purification plant in China which is just started.

In 1996-1998, researchers carried out a series of experimental research works such as on-site sludge water concentration and dehydration treatment on sludge water in a workshop of Minhang water works in Shanghai city, and good results are obtained. However, with the increasing importance of economic development and national environmental protection, a part of domestic water plants begin to build sludge treatment projects, and after entering the 21 st century, the water plants of Shijia city, beijing city, shanghai city Minhang, shenzhen, guangzhou city, tianjin, daqing, shenzhen Zhu Aoshui, and the like are established as sludge treatment projects and put into operation, but the water plants of the established sludge water treatment device have very low occupation ratio in the national water plants. The outdoor water supply design specification (GB 50013-2006) adds the sludge water treatment content of the water treatment plant, clearly prescribes the process flow of sludge water treatment of the water treatment plant, sludge regulation, concentration, dehydration, sludge cake treatment and utilization and the like, and prescribes that the water quality of natural water bodies such as river channels, ditches and the like discharged after the sludge water treatment of the water treatment plant accords with the current national standard of comprehensive sewage discharge standard.

At present, no other definite standard and design standard exists in the urban water works sludge treatment engineering, and the urban water works are successively constructed with sludge treatment facilities in China, so that the key technology and equipment for efficiently treating the sludge and saving water resources of the urban water works are very necessary.

(II) problems in the sludge treatment technology

(1) Immature process

The existing established mud-water treatment facilities of the tap water plant have insufficient researches on the generation path and physical and chemical properties of mud-water of the tap water plant, so that the design and application of the sewage and sludge treatment method in municipal industry are carried out to a great extent, and the reasonable consideration of the process cannot be combined with the self characteristics of the tap water plant.

2) The occupied area is large, and the currently established sludge water treatment facilities of a tap water plant, such as a Taiyuan city call water plant, have the treated water quantity of 40 ten thousand m ³/d and the occupied area of 3400m ²; ling Zhuang Water works, treated water volume is 75 ten thousand m ³/d, and occupied area is 9600m ²; in Guangdong, the treated water amount is 50 ten thousand m ³/d, and the occupied area is 4000m ². The occupied area is 80-128m ²/ten thousand m ³ according to the unit water yield meter. For an established running water plant in towns, no sludge water treatment site is reserved in the original design, and if a new sludge water treatment facility is built, the site cannot meet the requirements.

(3) High running cost and incapability of realizing full-automatic control

As the conventional process does not fully consider the reduction and recovery of the sludge water, the system is huge in arrangement and configuration, and the corresponding operation energy consumption and the agent addition amount are large. When the sludge dewatering system is designed, automatic control cannot be realized, operators need to monitor the whole process during operation, and the labor intensity of the operators is high.

(III) purpose and meaning of project study

(1) Needs of saving water resources

China is a country with quite abundant total water resources, the total water resources of the nationwide in 2014 are 27266.9 hundred million m ³, and the 6 th place of the world is occupied. However, the average occupation of our country is about 2200m ³, which is only 1/4 of the average world level, which is one of 13 water-poor countries in the world.

According to the production process of the waterworks, the waterworks sludge mainly comes from production drainage and production sludge discharge. The production drainage comes from the back flushing drainage of the filter tank, and the production sludge is produced by the sludge discharge of the reaction sedimentation tank. The back flushing sludge discharge amount of the filter tank is large (about 3.5% -5% of the produced water), the water content of the sludge is high (about 99.9%), most of the sludge can flow back and the sludge is less if the sludge is concentrated in a drainage tank for standing; the sludge water discharged from the sedimentation tank accounts for 1.5% -2% of the water yield, and the water content is relatively low (about 99.7%). The total mud water generally accounts for 4% -7% of the total water purifying amount of the water plant, and the direct discharge mode causes the waste of water resources and the increase of energy consumption.

(2) Environmental protection requirements

Although sludge treatment has been a development history for hundreds of years, water works sludge treatment has only been a development history for decades. The reason for this is that the sludge from the waterworks is essentially different from the traditional sludge, the sludge from the waterworks mainly comes from the sludge discharge of the sedimentation tank and the back flushing wastewater of the filter tank, and the components of the sludge mainly depend on the water quality of the water source of the waterworks and the added medicament. In water plants using rivers and rivers as water sources, the sludge is mainly mud sand due to the large content of the mud sand in the source water; the water works taking lake water as a water source have better source water quality, low sediment content and main components in the sludge: plankton, flocculant substances, organics, metal hydroxides (such as small amounts of ferro-manganese compounds) and substances added during treatment. The direct discharge of a large amount of untreated sludge water can cause the following damage to the environment:

(1) After a large amount of sediment and suspended matters in the mud water discharged from the water works enter the water body, the sediment is deposited, and the original hydraulic conditions of the water body are changed.

(2) The sewage from water works contains a great deal of suspended matters, organic matters and other pollutants which can cause pollution of the discharged water. It is estimated that all water works in Shanghai city produce dry sludge amount of 13.3 ten thousand t or more and organic matter of 1.3 ten thousand t or more each year, and the impact on environment is obvious.

(3) At present, most of the factories adopt aluminum salt as a coagulant, and a large amount of aluminum sludge is discharged into water, so that the harm to aquatic organisms and benthos is formed, and the ecological balance of the water is destroyed.

With the increasing importance of economic development and national environmental protection, the way of directly discharging sludge from water works is increasingly emphasized by common people in government, industry and people, especially, some water works which directly discharge sludge water to urban landscape water bodies have serious pollution to water bodies, and some water works have received the improvement notification issued by environmental protection departments.

The outdoor water supply design Specification issued in 2006 (GB 50013-2006) increases the sludge water treatment content of a water treatment plant, and requires that a new tap water plant must be constructed with corresponding sludge water treatment facilities. The traditional sludge water treatment process of the running water plant adopts sludge collection, a horizontal sedimentation tank, a mechanical stirring clarification tank and dehydration treatment, so that the problems of large occupied area, high investment cost, high operation cost and the like exist, corresponding sludge water treatment measures are not constructed in part of newly built running water plants, and the built running water plants are limited by sites, so that the new sludge water treatment facilities cannot be built.

In conclusion, the aim of the project research is to research a key technology and equipment for efficiently treating sludge water and saving water resources of a town water works, which has small occupied area, low investment cost and low operation cost.

Disclosure of Invention

The invention mainly solves the technical problem of how to provide the automatic control treatment method for the sludge dewatering process of the tap water plant, which reduces the occupied area of the tap water plant, reduces the engineering investment, saves the energy consumption, and realizes the recovery and the saving of water resources.

In order to solve the technical problems, the invention adopts a technical scheme that: the automatic control treatment method of the mud water and sludge dewatering process of the tap water plant is used for treating mud water and sludge concentration of the tap water plant, and comprises the following operation steps:

S1: obtaining a precipitation condition through analysis of sludge properties and a static precipitation test;

S2: determining the most suitable type and dosage of the medicament through experiments on the medicament;

S3: the high-efficiency sedimentation and concentration tank is adopted, and the high-efficiency sedimentation and concentration tank is combined with inclined plate sedimentation, so that the solid content of sludge in the bottom concentration area is improved, and the sludge directly enters a dehydration process to improve the concentration efficiency;

s4: the floating mud-water separation device is used for reducing the amount of the sludge water entering the subsequent equipment.

In a preferred embodiment, in step S1, the following method for analyzing sludge properties and testing static precipitation is included, which comprises the following steps:

SS1: measuring the sedimentation performance and the solid content of the sludge;

SS2: a step of judging the properties of the sludge;

in the step SS1, a sedimentation curve is drawn in the step of measuring the sedimentation performance of the sludge, and compression points and limiting solid flux are obtained through the sedimentation curve.

In a preferred embodiment, the sedimentation curve in step SS1 is prepared by the following steps:

1. making a sedimentation curve according to a sludge static sedimentation test;

2. Two tangential lines of the constant-speed sedimentation area and the compression area are made, an angle bisector is made by the intersection angle of the two tangential lines, and the intersection point of the two tangential lines and the sedimentation curve is the compression point;

3. Making a tangent line of a sedimentation curve through the compression point;

4. intercepting the sludge interface height H _u when the sludge discharge concentration C _u is reached on the ordinate axis, and taking parallel lines of the abscissa axis as intersecting with a tangent line passing through the compression point, wherein the abscissa value of the intersection point is tu;

5. if the sedimentation curve does not have a constant velocity sedimentation zone, entering a compression zone at the beginning, intersecting the sedimentation curve by using Hu as a parallel line of an abscissa, wherein the abscissa corresponding to the intersection point is tu;

6. obtaining tu by using a graphic method, and then substituting the tu into a formula to obtain the limit solid flux G;

In a preferred embodiment, the step SS1 of determining the solid content specifically includes determining by using a calculation formula of the solid content of the sludge and a calculation formula of the solid content of the sludge, where the calculation formula of the solid content of the sludge is: wherein A: calculating the water content of the sludge, and B:

Calculating the solid content of the sludge;

The calculation formula of the solid content of the sludge is as follows:

Wherein: pw: the water content (%) of the sludge; ps: solid content of sludge; w: the weight (g) of water in the sludge; s: total solids weight in sludge (g).

In a preferred embodiment, the determining step of the nature of the sludge in step SS2 comprises:

① . Measuring the solid content of the sludge;

② . A step of measuring the dewatering property of the sludge;

③ . A step of measuring the property of the sludge alum blossom;

④ . Analyzing the influence of the particle size distribution on the sludge dewatering property;

⑤ . Analyzing the influence of the density of alum on the dewatering property of sludge;

⑥ . And determining and analyzing the influence of compressibility and compression coefficient on the dehydration rate and the shear strength.

In a preferred embodiment, in the step ① of measuring the solid content of the sludge, impurities in the water and the sludge are combined together for adsorption and electric neutralization treatment.

In a preferred embodiment, the dewatering performance of the sludge in step ② is generally expressed in terms of specific resistance, the smaller the specific resistance, the better the dewatering performance of the sludge. Specific resistance is defined as the resistance to which the dry solids weight of a unit filter cake is subjected per unit filtration area; the formula of specific resistance is:

r: sludge specific resistance, (m/kg);

b: slope of t/V versus V curve, (s/m ⁶);

A: filtration area, (m ²);

p: pressure (Pa):

C: the weight of the mud cake produced per unit volume of filtrate, (kg/m ³);

W _b: dry sludge weight, (kg);

V _f: filtrate volume, (m ³).

In a preferred embodiment, in step ②:

When the specific resistance is less than or equal to 10X10 ¹⁰ m/kg, judging that the performance is good;

When the specific resistance is more than 100X10 ¹¹ m/kg, the sludge dewatering performance is poor.

In a preferred embodiment, the alum blossom density is measured in step ④ using a low osmotic pressure gradient medium in an analysis step of the effect of particle size distribution on the dewatering properties of the sludge.

In a preferred embodiment, in the compressive operation of step ⑥, the dewatering rate is reduced as the pressure increases in the dewatering process, and the compression of the sludge is expressed by the formula:

r₂＝r₁×ΔP^S

r ₁: specific resistance at pressure P ₁

R ₂: specific resistance at pressure P ₂

ΔP＝P₂-P₁

S: compression coefficient

The compression coefficient S is typically derived in steps of specific resistance r and pressure P,

Wherein: the S value is about 0.8 to about 1.5.

In a preferred embodiment, in step S2, cationic PAM is screened according to step S1, and three helical blade pipe mixing devices are used simultaneously, and the water flows through the pipe mixer to generate split flow, cross mixing and reverse rotational flow, so that the added agent is rapidly and uniformly diffused into the whole water body, and instantaneous mixing is achieved.

In a preferred embodiment, in step S3, a high-efficiency precipitation and concentration tank is used, and the high-efficiency precipitation and concentration tank is composed of a reaction zone, a concentration zone and a precipitation and separation zone.

In a preferred embodiment, the method further comprises the following steps:

(1) Setting a circulation mode as a reaction zone circulation mode, wherein the reaction mode is an internal circulation mode, so that the medicament, water and sludge in the step S2 are fully reacted;

(2) The sludge is provided with internal reflux, and the reflux sludge is used as a condensation nucleus for flocculation reaction, so that the flocculation is more compact;

(3) Umbrella-shaped inclined plate packing based on shallow pool principle greatly increases the surface area of the precipitation separation area, thereby improving the separation effect;

(4) And an organic polymer flocculant is adopted to accelerate the formation of flocs and reduce the flocculation reaction time.

In a preferred embodiment, in step (4), the sedimentation rate of the sludge is increased and the volume required for sludge concentration is reduced by the synergistic effect of flocculation cores, polymer bridging and particle collisions.

The beneficial effects of the invention are as follows: by researching the treatment process and technical equipment, compared with the traditional mud water treatment process, the optimized process and equipment have the advantages of reducing the occupied area of a tap water plant, reducing engineering investment, saving energy consumption and realizing water resource recovery and saving utilization.

Drawings

For a clearer description of the technical solutions of the embodiments of the present invention, the drawings that are needed in the description of the embodiments will be briefly introduced below, it being obvious that the drawings in the description below are only some embodiments of the present invention, and that other drawings can be obtained according to these drawings without inventive effort for a person skilled in the art, wherein:

FIG. 1 is a sedimentation graph of the self-control treatment method of the sludge water and sludge dewatering process of the water works.

Detailed Description

The following description of the technical solutions in the embodiments of the present invention will be clear and complete, and it is obvious that the described embodiments are only some embodiments of the present invention, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.

The invention provides a tap water plant sludge water and sludge dewatering process automatic control treatment method, which comprises the following specific embodiments.

Example 1

The automatic control treatment method of the mud water and sludge dewatering process of the tap water plant is used for treating mud water and sludge concentration of the tap water plant, and comprises the following operation steps:

SS2: a step of judging the properties of the sludge;

In a preferred embodiment, the step SS1 of determining the solid content specifically includes determining by using a calculation formula of the solid content of the sludge and a calculation formula of the solid content of the sludge, where the calculation formula of the solid content of the sludge is: Wherein A: calculating the water content of the sludge, and B: calculating the solid content of the sludge;

The calculation formula of the solid content of the sludge is as follows:

① . Measuring the solid content of the sludge;

② . A step of measuring the dewatering property of the sludge;

③ . A step of measuring the property of the sludge alum blossom;

r: sludge specific resistance, (m/kg);

b: slope of t/V versus V curve, (s/m ⁶);

A: filtration area, (m ²);

p: pressure (Pa):

C: the weight of the mud cake produced per unit volume of filtrate, (kg/m ³);

W _b: dry sludge weight, (kg);

V _f: filtrate volume, (m ³).

In a preferred embodiment, in step ②:

r₂＝r₁×ΔP^S

r ₁: specific resistance at pressure P ₁

R ₂: specific resistance at pressure P ₂

ΔP＝P₂-P₁

S: compression coefficient

The compression coefficient S is typically derived in the step of having a specific resistance r and a pressure P, wherein: the S value is about 0.8 to about 1.5.

In a preferred embodiment, the method further comprises the following steps:

Example 2

The automatic control treatment method of the sludge water and sludge dewatering process of the tap water plant is used for treating the sludge water and sludge concentration of the tap water plant and comprises the following operation steps:

(1) Through the analysis and research to the concentrator, confirm to adopt high-efficient sedimentation concentration pond to replace traditional mud concentration pond to reduce water purification plant occupation of land, improve concentration efficiency.

In order to solve the problem that the traditional process has large occupied area, is suitable for the construction of the existing water plant, especially the reconstruction requirement of the built water plant, and has very strict occupied area requirement on the selected process. The concentration tank is a key structure for treating sludge, and because the sludge generated by a running water plant taking surface water as a water source is not easy to concentrate, if the traditional gravity type sludge concentration tank is adopted, the surface load of the concentration tank must be reduced very low, so that the occupied area of the concentration tank is larger, and the concentration effect is poor. Therefore, the project adopts the high-efficiency sedimentation and concentration tank as the sludge concentration tank, and combines the inclined plate sedimentation principle to replace the traditional gravity concentration tank.

(2) Through experiments on the medicaments, the most suitable medicament type and the dosage are determined, and the best treatment effect is achieved.

Since a large amount of inorganic flocculating agents such as polyaluminium chloride and the like are added in the treatment of raw water in a tap water plant, the inorganic flocculating agents in sludge water are in a saturated state, and the addition of inorganic flocculating agents such as polyaluminium chloride or polymeric ferric sulfate and the like cannot promote the sedimentation of sludge in the sludge water. At present, the common organic polymeric flocculant in sludge water treatment is polyacrylamide, and the organic polymeric flocculant can be divided into cationic, anionic and nonionic 3 major categories according to the charge of the organic polymeric flocculant, and the most suitable type and dosage of the medicament are determined through research.

(3) The best conditions for precipitation were studied by analysis of sludge properties and laboratory stationary precipitation tests.

The waterworks sludge contains various kinds of moisture, the existence states of the moisture are different, the surface activity is extremely complex, and the moisture in the sludge is classified into 4 types by the fisher: the free water, the alum water, the capillary water and the combined water are different in existence form, property and sedimentation performance of the water in each state, and the optimal conditions of sedimentation are researched through experiments.

(4) And (3) researching how to reduce the engineering floor area and the equipment energy consumption through the floating mud-water separation device.

The continuous inflow water adjusting tank is adopted, so that larger tank capacity is needed to buffer water quantity, and the operation effect is poor; the intermittent water inflow adjusting tank is adopted, the turbidity above the water outlet can be guaranteed to meet the recycling requirement only by long static sedimentation time, and the water is often discharged to a water pump with larger specification in order to shorten the water discharge time, so that the operation cost is high, the automation degree is poor, and the quality fluctuation of the recycled water is large. The floating mud-water separation device is adopted in the project, so that the drainage time and the sludge precipitation time can be completely separated, the cost is saved without adding a medicament, the increase of the sludge quantity is reduced, and importantly, the sludge quantity entering the subsequent equipment is reduced, the design load and the operation load of the subsequent equipment are greatly reduced, and the reduction of the occupied area and the great reduction of the operation energy consumption are realized.

In the study of the properties of sludge, the following operational aspects are included:

and (I) measuring the sedimentation performance and the solid content of the sludge.

The sludge sedimentation performance mainly has the natural sedimentation characteristics of sludge water with different solid contents, the compacted solid flux of the sludge water and the concentration time required by the subsequent dehydration treatment.

(1) Sedimentation curve:

A static sedimentation characteristic curve of the sludge water discharged from the sedimentation tank, which is made by a 1000mL measuring cylinder. It can be seen that the sedimentation rate of the muddy liquid surface is continuously reduced along with the time increase in the static sedimentation process of the sludge, and the sedimentation characteristics of the sludge with different solid contents are obviously different. When the solid content is low, the sludge in the initial stage can quickly form a sedimentation surface, the sedimentation is quick, the sludge quickly reaches a compacting point, and a sedimentation curve is obviously turned around the compacting point. Along with the increase of the solid content of the sludge discharge water, the time for forming a sedimentation surface by the sludge is correspondingly prolonged, the constant-speed sedimentation process in the initial stage is not obvious, the sedimentation rate of a sludge interface is slower and slower, the time-lapse curve gradually becomes gentle, and the compaction point is not obvious. This is mainly because: and at low solid content, particles in the muddy water interfere with group settlement. The sedimentation rule is that the flocculation particles are increased to accelerate the sedimentation due to the self-flocculation effect of the particles. But simultaneously, the resistance of sinking particles is correspondingly increased due to the increase of the flow velocity of relative ascending water flow, so that a stress balance condition is quickly achieved. At this time, the muddy liquid level enters a constant-speed sedimentation stage. Along with the sedimentation, the concentration of particles in the muddy water is larger and larger along the sedimentation direction of the particles, and the particles are subjected to integral compression sedimentation. At this time, mud water floc particles are further close to and mutually contacted, and the molecular force among the particles is more obvious and strengthened. The network of flocks appears very quickly and will form a network of integers in a short time. Meanwhile, due to the rapid increase of the limit shear stress in the water body, the relative motion of the floccule particles is gradually weakened or even eliminated, so that the particles with different sizes sink in an integral form, and no sorting and relative motion of the particles exist. Appearance is that the sinking speed of the muddy liquid level is further reduced.

The compression point and the limit solid flux can be calculated through a sedimentation curve, and the specific method is as follows:

4. The sludge interface height H _u,(H_u when the sludge concentration C _u is reached is intercepted on the ordinate axis, and can be calculated according to a Kynch formula C ₀H₀＝C_uH_u), a parallel line with an abscissa is made to intersect with a tangent line passing through a compression point, and the abscissa value of the intersection point is tu; 5. if the sedimentation curve does not have a constant velocity sedimentation zone, entering a compression zone at the beginning, intersecting the sedimentation curve by using Hu as a parallel line of an abscissa, wherein the abscissa corresponding to the intersection point is tu;

6. and (5) obtaining tu by using a graphic method, and then substituting the tu into a formula to obtain the limit solid flux G.

(2) Sludge moisture content and solid content

The amount of the water contained in the sludge is called the water content, and the water content of the sludge is expressed by the water content, namely the weight percentage of the water contained in the sludge per unit weight.

The water content of the sludge can be calculated by the following formula:

pw: sludge moisture content (%)

W: weight of moisture in sludge (g)

S: total solids weight in sludge (g)

The solid content of the sludge can be calculated by the following formula:

ps: the solid content of the sludge is%

S: total solids weight in sludge (g)

W: weight of moisture in sludge (g)

(II) Properties of sludge

1. Solid content of sludge

Moisture in sludge: the waterworks sludge contains various kinds of water, the existence states of the water are different, and the surface activity is extremely complex. There are many classifications for water in sludge, and fisher (Vesilind) classifies water in sludge into 4 classes: (1) Free water exists between particles, is little in surface tension or capillary action, and can be removed by simple gravity concentration; (2) The alum water is caught in the sludge alum flowers by a net and can be removed by mechanical dehydration; (3) Capillary water among sludge particles is larger in surface tension or capillary action, is not easy to lose under the action of gravity, and can be removed only through extrusion and sludge particle deformation; (4) water is bound, and water chemically bound by alum particles. Among the water in the sludge, the free water is easiest to remove, and can be removed only by simple gravity concentration or mechanical dehydration, but the combined water is most difficult to remove, and the sludge cake can be partially removed by heating, drying or incinerating. The form of partial alum water or capillary water can be changed into free water which is easy to lose by adding chemical agents (organic high molecular polymers, acid, alkali and the like) for pretreatment or freezing and thawing pretreatment. The content of various kinds of moisture in the sludge will directly affect the solid content of the sludge after concentration and dehydration of the sludge, so that the knowledge thereof is very important.

Factors affecting the change in solids content: the solid content of the sludge in the waterworks usually varies greatly, which is mainly determined by the raw water property, the type and the addition amount of the coagulant, whether lime is used or not, and the like. Generally, the higher the suspended solids and calcium carbonate content, the higher the solids content of the sludge. Therefore, when the turbidity of the raw water is low, the solid content of the sludge is low, and when the turbidity of the raw water is high, the solid content of the sludge is high. Knocke et al showed that: the turbidity of raw water, the adding amount of coagulant and the coagulation mechanism have great influence on the concentration and dehydration properties of sludge. When the pH of the coagulation is 8.1, the solid content of the mud cake after mud water concentration and dehydration is much lower than that of the mud cake after the pH is 6.2; the solid content of the sludge when the aluminum sulfate is added is obviously lower than that when the aluminum sulfate is added in a low amount; from the coagulation mechanism, the net capturing is lower than the solid content of the sludge generated by adsorption-electric neutralization. Therefore, the electric neutralization treatment of adsorption by combining impurities in water with sludge is most ideal, the dosage of aluminum salt is less, the proportion of suspended particles in the sludge is higher, the proportion of aluminum hydroxide is lower, and the sludge is easy to dehydrate. Thus, in considering the selection of coagulation conditions, the following should be noted: (1) lowering the pH at the time of coagulation; (2) Reducing the ratio of the coagulant dosage to the turbidity of the inlet water; (3) coagulation mechanism should be controlled to adsorption-electric neutralization.

2. Specific resistance

The dewatering performance of sludge is generally expressed by specific resistance, and the smaller the specific resistance is, the better the dewatering performance of sludge is. Specific resistance is defined as the resistance per unit of filter area, per unit of dry solids weight of filter cake. The formula of specific resistance is shown as follows:

r: sludge specific resistance, (m/kg);

b: slope of t/V versus V curve, (s/m ⁶);

A: filtration area, (m ²);

p: pressure (Pa):

C: the weight of the mud cake produced per unit volume of filtrate, (kg/m ³);

W _b: dry sludge weight, (kg);

V _f: filtrate volume, (m ³).

The range of specific resistance variation is large, and it is generally considered that sludge having a specific resistance of 10X10 ¹⁰ m/kg or less is easily dehydrated, whereas when the specific resistance is more than 100X10 ¹¹ m/kg, the sludge dehydrating performance is poor. The specific resistance of coagulant sludge increases with increasing pH and decreases with increasing turbidity of raw water. In the coagulation process, if the water content in the sludge alum blossom is high, the dehydration speed is low, the dehydration speed of aluminum hydroxide sludge generated by low-turbidity raw water is low, and the solid content of the dehydrated mud cake is low.

3. Properties of sludge alum

The properties of alum, such as particle size distribution and alum density, have great influence on sludge concentration, dewatering rate and dewatering degree.

4. Particle size distribution

The geometry of the sludge alum blossom generated in the water treatment process has extreme irregularities and disorder, and is difficult to describe. Some studies usually analyze sludge particles as spheres, but with larger errors. Knocke et al, when observing sludge alum by microscopy, consider that most sludge particles are more elliptical and measure the ratio of the major axis to the minor axis of the sludge particles to be about 0.5-0.75. In recent years, there have been studies to describe the structure of sludge flocs, the characteristics of sludge alum and the characteristics of filter cakes mathematically using an irregular fragment theory describing the indeterminate morphology or disorder, and to express the effective irregular fragment density (ρ _f-ρ₁) as a function of the ratio (c) of one irregular fragment of radius R consisting of n elementary particles of radius R ₀ and the density (ρ _p) of one elementary particle, see formula:

The size D of the irregular fragments can be obtained by the slope of a double logarithmic curve of the diameter and the effective alum blossom density, the theoretical value of the size of the irregular fragments is 1-3, and the research shows that the content of bound water in the sludge alum blossom is obviously reduced along with the increase of the size of the irregular fragments, and the two are obvious linear relations.

Regarding the influence of particle size distribution on sludge dewatering properties, there have been many studies on the fact that the particle size distribution of the graph has a great influence on sludge dewatering, and as the sludge size increases, the specific resistance of the sludge decreases and the sludge dewatering properties improve accordingly, but there have been studies on the fact that the results are suspected. Because of the influence of factors such as the height irregularity of the sludge particles, the measurement method and the like, the influence degree of the particle size distribution on the sludge dewatering property is not determined in the prior art, and more detailed research is needed.

5. Density of alum blossom

The density of alum blossom is another important factor affecting the dewatering properties of sludge. It is considered that the influence of the alum density on the dewatering effect is more important than the influence of the alum particle size distribution, and in the concentration and various mechanical dewatering researches, the density of alum and the solid content of the dehydrated mud cake are closely related. As the density of alum blossom increases, the solid content of the sludge after concentration and dehydration also increases.

As the suspended solids (kaolin) in the alum flocs increase, the alum flocs density increases, the solid content of the mud cake after sedimentation and dehydration increases, and as regards the influence of organic matters on the alum flocs density, it is considered that as the organic matter content in the alum flocs increases, the alum flocs density decreases, and the dehydration rate and the solid content of the mud cake after dehydration decrease. There are reports on the difference in alum density of aluminum sludge, which is related to the test method and the content of organic matters (TOC) in sludge, and the research results show that the alum density of aluminum sludge is in the range of 1.14-1.22.

There are many methods for measuring alum blossom density, but it is generally considered more reasonable to measure alum blossom density using low osmotic pressure gradient media than other commonly used methods, such as sucrose. The use of high osmotic pressure media may result in higher density values than practical, since high osmotic pressure causes water to flow out of the sludge flocs during the measurement process.

6. Compressibility of

Compressibility is considered to be a result of alum deformation during dewatering, and most coagulant-added water mill sludge is highly compressible. The main consequence of compressibility is that the dewatering rate decreases as the pressure increases in the dewatering process.

The compressibility of sludge is generally expressed by the formula:

r₂＝r₁×ΔP^S

r ₁: specific resistance at pressure P ₁

R ₂: specific resistance at pressure P ₂

ΔP＝P₂-P₁

S: compression coefficient

The compression coefficient S is typically determined from a log-log plot of the specific resistance r and the pressure P. For conventional sludge, the S value is about 0.8-1.5; the S value of the softened sludge can be reduced to 0.4, because the sludge is mainly composed of calcium carbonate. Many experiments have shown that sludge can deform under pressure, resulting in increased filtration resistance.

The compression coefficient of the aluminum sludge is approximately equal to 1.0, and the coefficient of the lime sludge is slightly lower, which indicates that the lime sludge is slightly lower in compressibility than the aluminum sludge. The change of the alum density does not have great influence on the compressibility, and the change of the particle size does not influence the compressibility of the sludge.

For low turbidity raw water, the content of hydroxide in the commonly produced sludge is high, and when pressure is applied, the dehydration performance of the sludge is poor; in contrast, for sludge containing a large amount of inert particles, the dewatering performance does not significantly deteriorate when pressure is applied. This is mainly due to the influence of the compressibility of sludge, so that the compressibility of sludge should be considered in designing a sludge dewatering system.

7. Shear strength

Shear strength is an important property affecting sludge disposability, especially when designing and analyzing landfill stability of the soil. Conventionally, sludge solid content after dehydration is taken as a method for measuring sludge treatment and final disposal properties, but researches show that sludge with solid content in a large range has similar disposal properties, and the disposability of the sludge cannot be directly judged only by the solid content of a sludge cake. It is proposed that the shearing strength of Chuangdang mud cake reaches 292-390kg/m ²(0.02-0.05tons/ft²), and the method can meet the sludge disposal requirement. According to the range of the shear strength requirement, for aluminum sludge, the treatment requirement is met when the solid content is 15-20%, and some lime softening sludge may need more than 50% of the solid content to meet the treatment requirement.

In one embodiment, the study of the floating mud-water separator is included.

According to the treatment process of a tap water plant, sludge mainly comes from filter tank back flushing drainage and reaction sedimentation tank mud drainage, and main solids in the filter tank back flushing wastewater are fine alum flowers and flocculent objects broken in the flocculation sedimentation process, the content of the solids is about 0.04%, and the sedimentation performance is poor; the main solid discharged from the sedimentation tank is a flocculation sedimentation product, the sludge in the sedimentation tank is compressed, the solid content is higher, generally between 0.5 and 1 percent, the particle geometry is larger, and the sedimentation separation is easy. According to the quality of the backwash water of the filter tank and the sludge water discharged from the sedimentation tank, the conventional adjusting tank can be roughly divided into the following two forms:

And (3) building: the backwash wastewater regulating tank and the sludge discharging water regulating tank can be independently arranged, and the two types of wastewater are independently treated and conveyed to the concentration process, so that the concentration of sludge is higher, but the structure is more complex, the occupied area is larger, the equipment is more and the manufacturing cost is high.

And (3) combined construction: the two kinds of waste water are combined in the same pool to treat the sludge with slightly lower concentration, but the structure is simple, the occupied area is small, the equipment is less and the cost is low.

Combines the advantages and disadvantages of two forms of the traditional regulating tank, develops and develops a floating mud-water separation device, and leads the functions of the original regulating tank to be diversified through the floating mud-water separation device, thereby not only being capable of regulating the water quantity and the water quality, but also playing the role of concentrating the sludge and realizing the purpose of multi-stage concentration and decrement, and solving the problems of low sludge concentration, poor concentration effect of the follow-up sludge concentration tank and large volume of the original combined regulating tank.

Working principle of floating mud-water separation device

Setting the sludge discharge time of the reaction sedimentation tank and the back flushing time of the filter tank scientifically and reasonably, discharging back flushing drainage of the filter tank and sludge discharge water of the reaction sedimentation tank into a combined regulating tank in a period of time, and enabling the regulating tank to enter a static sedimentation process after the drainage is completed; the static sedimentation time is determined through early analysis and experiments of the field water quality, when the turbidity index of the surface clear water reaches the recycling requirement, the floating type mud-water separation device starts to work, the surface clear water is collected by the floating type mud-water separation device and then is conveyed into the water inlet regulating tank of the water works, the floating type mud-water separation device automatically descends along with the water level descending, and the surface clear water is discharged all the time by the floating type mud-water separation device in the process, so that the water quality entering the water inlet regulating tank of the water works is ensured; when a large amount of surface clear water is discharged and the water level is reduced to a certain extent, and the turbidity index of the surface clear water cannot meet the recycling requirement, the floating mud-water separation device stops working, and a mud scraper, a stirrer and a mud lifting pump in the regulating tank start working to convey the concentrated mud to a subsequent link.

Study on the static sedimentation treatment effect of the sludge water:

1. Test method

And (5) obtaining mixed sludge water in a comprehensive regulating tank of a certain water plant, and conveying the mixed sludge water to a sedimentation column by using a submersible pump for static sedimentation test. Four different groups of water samples are taken, and supernatant liquid is taken at 0, 0.5, 1, 2 and 4 hours respectively, turbidity of the supernatant liquid is detected, and influence of hydraulic retention time on the quality of the supernatant liquid is studied.

2. Test device

The sedimentation column adopts an acrylic organic glass column with the diameter of 250mm and the height of 1650mm, a 1000ml beaker and the like.

3. Test results and analysis

Four sets of mixed sludge water were subjected to a static precipitation treatment test, and specific experimental data are shown in the following table.

By analyzing the data of the analysis, the turbidity change is obvious in the time period from 0h to 0.5h, and after exceeding 0.5h, the turbidity change of the supernatant fluid is not obviously different from the ratio of 0.5h and is gradually stable as the time is prolonged. The turbidity of the sludge water with different turbidity shows a descending trend along with the change of the turbidity, the sedimentation performance of the sludge water with different turbidity is slightly different, the turbidity of the water sample with 4 groups tends to be stable after the water sample is statically settled for 0.5h, and the turbidity change of the water sample after continuous settlement is smaller.

Study on static sedimentation treatment effect of sludge water by adopting layered drainage mode:

1. Test method

And (5) obtaining mixed sludge water in a comprehensive regulating tank of a certain water plant, and conveying the mixed sludge water to a sedimentation column by using a submersible pump for static sedimentation test. Taking the same group of water samples at the sampling ports 1#, 2#, 3# and 4# respectively, taking supernatant liquid at different times of 0, 0.5, 1,2 and 4 hours, detecting the turbidity of the supernatant liquid, and researching the influence of hydraulic retention time on water quality at different liquid levels.

2. Test device

The sedimentation column adopts an acrylic organic glass column with the diameter of 250mm and the height of 1650mm, and is the same as a 1.2.2 middle test device, a1000 ml beaker and the like.

3. Test results and analysis

Static sedimentation treatment tests of different liquid level depths at different times are carried out on the same group of mixed sludge water, and specific experimental data are shown in the following table.

Through the analysis of the data of the analysis, the turbidity change is obvious in the time period from 0h to 0.5h along with the sedimentation time of the water quality at different liquid levels; after exceeding 0.5h, the water quality change at different liquid levels and the 0.5h ratio are not obvious, but turbidity is still in a descending trend, the water quality of the 2# sampling port is close to the water quality level of the 1# sampling port at the time of 1h, the water quality of the 3# sampling port is close to the water quality level of the 1# sampling port at the time of 2h, the water quality of the 3# sampling port is close to the water quality level of the 1# sampling port at the time of 0.5h, and the water quality of the 3# sampling port is close to the water quality level of the 1# sampling port at the time of 4h and is different.

In the analysis of the static sedimentation treatment effect of the floating mud-water separation device on the sludge water, a continuous-flow inflow regulating tank is adopted, and in the running process, because the fluctuation of the water inflow is large, in order to reduce the impact on the sludge deposited in the regulating tank, a large tank capacity is often needed to buffer the water inflow, and the running effect is poor; in the running process, the water is discharged in a fixed way, the static sedimentation time is long to ensure that the turbidity above the water outlet meets the recycling requirement, and the water is often discharged to a water pump with a larger specification in order to shorten the water discharge time, so that the running cost is high, the automation degree is poor, and the fluctuation of the water quality of the recycled water is large.

The floating mud-water separation device is adopted to completely separate the drainage time and the sludge sedimentation time, and the automatic monitoring system monitors the supernatant water quality of the regulating tank in real time, so that the floating mud-water separation device is automatically started when the requirement of reuse water is met; as the water level drops, the floating mud-water separation device also drops, which is beneficial to ensuring that the water discharged from the regulating tank is always supernatant, and avoiding the fluctuation of the water quality of the reuse water; when the sludge is discharged to the vicinity of the lower sludge enrichment zone, the floating sludge-water separation device stops working. The static precipitation mode does not need to add a medicament, so that the cost is saved, the medicament does not need to be added to the sludge water, further pollution of the sludge water is avoided, and the increase of the sludge amount is reduced. The floating mud-water separation device is adopted, so that the time required by static sedimentation and drainage of the regulating tank is greatly shortened, the tank capacity of the traditional regulating tank can be effectively reduced, the occupied area of the regulating tank is reduced, and the automation degree of the whole mud-water treatment is improved; especially for a running water plant without a mud-water treatment facility, the available area in the plant is limited, and the floating mud-water separation device and the combined regulating tank can better solve the problem of shortage of the mud-water treatment facility, thereby having higher economic value and social benefit.

In the research process of the high-efficiency concentration device:

in the whole sludge water discharging process of a water works, the sludge water concentrating process plays an important role, the concentration of the bottom flow of the concentrating tank directly influences the sludge dewatering effect, the cost of the whole process is determined, and the economic benefit of enterprises is related. The sludge concentration process can adopt gravity concentration, air floatation concentration, centrifugal concentration, hydrocyclone concentration and the like. Gravity concentration is suitable for the sludge property of a water works because of simple structure, convenient management, excellent concentration effect and low cost, and is more applied to the sludge concentration of the water works and is preferentially adopted under the condition of permission of land.

The traditional continuous flow gravity concentration tank is mainly divided into a vertical flow type gravity concentration tank and a radial flow type gravity concentration tank. The vertical flow type concentrating tank is mainly an inclined tube (plate) concentrating tank, has high concentrating efficiency and small occupied area, but has poor regulating capability, and the regulating volume is insufficient when the high turbidity of raw water is handled. The radial flow type concentration tank has three areas, namely an upper clarification area, a middle stagnation area and a compression area at the lower part, and has stronger regulating capability but large occupied area. The high-efficiency concentration device is based on the principle of a high-density sedimentation tank, combines the enhanced flocculation process, preferably enhances the flocculation effect of an organic polymer flocculant, improves the solid content of sludge in a bottom concentration zone, adopts the traditional gravity concentration tank, ensures the solid content of sludge at the bottom of the high-efficiency concentration device to be about 3%, ensures the solid content of sludge at the bottom of the high-efficiency concentration device to be more than 5%, and can directly enter a dehydration process without sludge modulation.

The high-efficiency concentration device is a high-efficiency integrated sedimentation concentration tank, and consists of a reaction zone, a concentration zone and a sedimentation separation zone. The process has the following five main characteristics:

(1) The special internal circulation reaction zone is designed, and the medicament, water and sludge fully react;

(2) The sludge is subjected to internal reflux design, and the reflux sludge is used as a condensation nucleus for flocculation reaction, so that the flocculation is more compact;

(3) Umbrella-shaped inclined plate packing based on shallow pool principle greatly increases the surface area of a precipitation separation area and improves separation effect;

(4) The optimized organic polymer flocculant is adopted to accelerate the formation of the floccule, so that the flocculation reaction time is reduced;

(5) Can bear the change of the water quality and the flow of the inflow water in a large range, and has high degree of automation.

In the research of the enhanced flocculation effect of the high polymer organic flocculant: since a large amount of inorganic flocculating agents such as polyaluminium chloride and the like are added in the treatment of raw water in a tap water plant, the inorganic flocculating agents in sludge water are in a saturated state, and the addition of inorganic flocculating agents such as polyaluminium chloride or polymeric ferric sulfate and the like cannot promote the sedimentation of sludge in the sludge water. The organic polymeric flocculant is added, and the particles form a polymer bridge and sink together, so that the common organic polymeric flocculant in the sludge water treatment at present is polyacrylamide, and the organic polymeric flocculant can be classified into cationic, anionic and nonionic 3 types according to the charge of the organic polymeric flocculant.

1. The test method comprises the following steps:

obtaining mixed sludge water in a comprehensive regulating tank of a certain water plant, performing a static sedimentation test in a sedimentation column, taking bottom concentrated sludge subjected to static sedimentation for 2 hours as a research object for strengthening flocculation effect, taking 1000mL of the concentrated sludge, shaking uniformly, placing the mixture in a beaker, respectively adding polyacrylamide of different types and different concentrations, mixing and reacting under certain stirring intensity and time on a synchronous six-link stirrer, then pouring a sample into a 1000mL measuring cylinder for sedimentation for 30 minutes, and observing the numerical value of the sedimentation ratio of the sludge to judge the type and the adding amount of the optimal polyacrylamide.

2. Test device:

the sedimentation column adopts a test device in 1.2.2, a 1000ml glass measuring cylinder, a 1000ml beaker, a synchronous six-link stirrer and the like.

3. Test results and analysis:

the experiment selects four organic polymeric flocculants of PAM1#, PAM2#, CPAM1# and CPAM2#, and the reinforced flocculation experiment is carried out on the concentrated sludge, and specific experimental data are shown in the following table.

Through the analysis of the data of the analysis, the type and the addition amount of PAM are important factors influencing the sedimentation property of the sludge discharge water, and the larger the addition amount is, the smaller the sludge discharge water SV30 is, the lower the turbidity of flocculated water is, and the better the sedimentation property of the concentrated sludge is. When the addition amount is 30mg/L, the mud water SV30 after tempering of PAM1#, PAM2#, CPAM1# and CPAM2# is respectively 50%, 38%, 37% and 32%, and the mud water SV30 is not changed greatly along with the increase of the addition amount, and the excessive addition amount of PAM can cause the exceeding of PAM monomers when flocculating effluent is recycled. After CPAM2# is added, the sludge water SV30 is the smallest, which shows that CPAM2# has the best effect of improving the sedimentation performance of the sludge water, the SV30 is 35% when the CPAM2# is added at 20mg/L, the addition is obviously superior to other flocculating agents, the addition is continuously increased, and the SV30 change range is smaller.

4. Feasibility of PAM applied to mud water flocculation treatment process:

The sludge obtained in the test comes from a tap water plant taking yellow river water as a water source, the yellow river water is poor in quality, the organic matter content in the water is high, and the sediment content, in the test, the concentration and sedimentation performance of the discharged mud water can be obviously improved by adopting Cationic Polyacrylamide (CPAM), and the turbidity and chromaticity in the water are removed. The sludge mainly contains colloid particles, suspended particles and organic substances with higher concentration, so that the potential of the sludge water is very low, the sedimentation performance is basically not improved by changing the charge amount in the sludge water, and the high-content and high-charge-density Cationic Polyacrylamide (CPAM) has stronger adsorption bridging and net capturing effects, so that the sludge can be further concentrated better. For a tap water plant which takes a water body with better water quality and lower organic matter content as a water source, when the organic polymeric flocculant is selected, aluminum salt is added in the raw water treatment process flow of the tap water plant, the electronegativity of Zeta potential is obviously reduced through double-layer compression, and the solid content of sludge can be greatly improved by adopting anionic Polyacrylamide (PAM).

In the research process of the sludge reflux on the reinforced flocculation effect:

The efficient concentration device adopts a special sludge reflux process, the flocculation effect can be enhanced by adopting the sludge reflux process, mainly the sedimentation velocity of sludge can be effectively improved by adopting the reflux process through the synergistic effect of flocculation cores, polymer bridging, particle collision and the like, and the volume required by sludge concentration is greatly reduced.

1. Test method

Obtaining mixed sludge water in a comprehensive regulating tank of a certain water plant, performing a static sedimentation test in a sedimentation column, taking the bottom concentrated sludge after static sedimentation for 2 hours, taking 1000mL of the bottom concentrated sludge, shaking uniformly, placing the bottom concentrated sludge in a beaker, and adding 20mg/l of CPAM2# under certain stirring intensity and time for reinforced flocculation; separating out bottom sludge after standing and precipitating the sludge subjected to reinforced flocculation for 0.5h, discharging the bottom sludge into a beaker, uniformly stirring, mixing the bottom sludge with the bottom concentrated sludge subjected to standing and precipitating for 2h according to a certain proportion, adding CPAM2# with different concentrations under a certain stirring intensity and time for reinforced flocculation, and observing the numerical value of the sludge sedimentation ratio to judge the optimal sludge reflux ratio.

2. Test device

The sedimentation column adopts the test device in the above experiment: a 1000ml glass measuring cylinder, a 1000ml beaker, a 1000ml separating funnel, a synchronous six-link stirrer and the like.

3. Test results and analysis

CPAM2# organic polymer flocculant is selected in the experiment, and the experiment is carried out by adding sludge subjected to reinforced flocculation in different proportions into unreinforced flocculation, wherein the specific experimental data are shown in the following table.

Through the analysis of the data of the analysis, as the sludge reflux ratio of the concentrated sludge added with CPAM#2 flocculating agents with different concentrations is increased, SV30 is reduced and then increased, which shows that the reflux sludge can play a role in adsorbing and bridging, and plays a role in strengthening flocculation. With the increase of the reflux ratio, the residual turbidity is increased, probably because the concentration of inorganic particles is increased when the reflux ratio is too high, the flocculation of raw water is counteracted by excessive reflux sludge, and meanwhile, more positive charges are adsorbed on the periphery of the sludge due to excessive CPAM, so that Zeta is increased and stabilized again.

Therefore, the invention has the following advantages: by researching the treatment process and technical equipment, compared with the traditional mud water treatment process, the optimized process and equipment have the advantages of reducing the occupied area of a tap water plant, reducing engineering investment, saving energy consumption and realizing water resource recovery and saving utilization.

The foregoing description is only illustrative of the present invention and is not intended to limit the scope of the invention, and all equivalent structures or equivalent processes or direct or indirect application in other related arts are included in the scope of the present invention.

Claims

1. The automatic control treatment method of the sludge water and sludge dewatering process of the tap water plant is used for treating the sludge water and sludge concentration of the tap water plant and is characterized by comprising the following operation steps of:

S4: the floating mud-water separation device is used for reducing the amount of the sludge water entering the subsequent equipment;

in step S1, the following method for analyzing the sludge property and testing static precipitation is included, which comprises the following steps: SS1: measuring the sedimentation performance and the solid content of the sludge;

SS2: a step of judging the properties of the sludge;

in the step SS1, a sedimentation curve is drawn in the step of measuring the sedimentation performance of the sludge, and compression points and limiting solid flux are obtained through the sedimentation curve;

the specific operation steps of the sedimentation curve in the step SS1 are as follows:

4. Intercepting the sludge interface height H _u reaching the sludge discharge concentration C _u on the ordinate axis, and taking parallel lines of the abscissa axis as intersecting with a tangent line passing through the compression point, wherein the abscissa value of the intersection point is tu;

the concrete operation steps of the solid content measurement in the step SS1 are that the calculation formula of the water content of the sludge and the calculation formula of the solid content of the sludge are utilized for judging,

The calculation formula of the water content of the sludge is as follows: Wherein A: calculating the water content of the sludge, and B: calculating the solid content of the sludge;

The calculation formula of the solid content of the sludge is as follows: Wherein: pw: the water content (%) of the sludge; ps: solid content (%) of sludge; w: the weight (g) of water in the sludge; s: total solids weight in sludge (g);

the step of determining the nature of sludge in step SS2 includes:

① . Measuring the solid content of the sludge;

② . A step of measuring the dewatering property of the sludge;

③ . A step of measuring the property of the sludge alum blossom;

2. The method for automatically controlling the dehydration process of sludge water and sludge in a water works according to claim 1, wherein in the step ① for measuring the solid content of the sludge, impurities in the water and the sludge are combined together for adsorption and electric neutralization treatment.

3. The method for automatically controlling the dehydration process of sludge water and sludge in a water works according to claim 1, wherein in step ②, the dehydration performance of the sludge is represented by specific resistance, the smaller the specific resistance is, the better the dehydration performance of the sludge is,

Specific resistance is defined as the resistance to which the dry solids weight of a unit filter cake is subjected per unit filtration area;

The formula of specific resistance is:

r: sludge specific resistance, (m/kg);

b: slope of t/V versus V curve, (s/m ⁶);

A: filtration area, (m ²);

p: pressure, (Pa):

C: the weight of the mud cake produced per unit volume of filtrate, (kg/m ³);

W _b: dry sludge weight, (kg);

V _f: filtrate volume, (m ³).

4. The method for automatically controlling the dehydration process of sludge water and sludge in a tap water plant according to claim 3, wherein in step ②:

5. The method for automatically controlling the dehydration process of sludge water and sludge in a water works according to claim 1, wherein the alum blossom density is measured by using a low osmotic pressure gradient medium in the analysis step of the influence of the particle size distribution on the dehydration property of sludge in step ④.

6. The method according to claim 1, wherein in the step ⑥, in the operation of compressibility, the dehydration rate is decreased when the pressure is increased in the dehydration process, and the compressibility of sludge is expressed by a formula:

r₂＝r₁×ΔP^S

r ₁: specific resistance at pressure P ₁

R ₂: specific resistance at pressure P ₂

ΔP＝P₂-P₁

S: compression coefficient

The compression coefficient S is obtained from the steps of the specific resistance r and the pressure P, in particular the compression coefficient S is obtained from the log-log of the specific resistance r and the pressure P,

Wherein: the S value is about 0.8 to about 1.5.

7. The automatic control treatment method for the sludge water and sludge dewatering process of the water works according to claim 1, wherein in the step S2, cationic PAM is screened according to the step S1, meanwhile, three spiral blade pipeline mixing devices are adopted, and water flows are split, cross-mixed and reverse rotational flow are generated through a pipeline mixer, so that the added medicament is rapidly and uniformly diffused into the whole water body, and instantaneous mixing is achieved.

8. The automatic control treatment method for the sludge water and sludge dewatering process of the water works according to claim 1, wherein in the step S3, a high-efficiency sedimentation concentration tank is adopted, and the high-efficiency sedimentation concentration tank consists of a reaction zone, a concentration zone and a sedimentation separation zone.

9. The self-control treatment method for the sludge water and sludge dewatering process of the water works according to claim 8, further comprising the following operation steps:

10. The method according to claim 9, wherein in the step (4), the sedimentation rate of the sludge is increased and the volume required for concentrating the sludge is reduced by the synergistic effect of flocculation cores, polymer bridging and particle collision.