A high-molecular composite water treatment coagulant, a preparation method, application and sewage treatment method

Abstract

The application belongs to the technical field of water treatment, and particularly relates to a high-molecular composite water treatment coagulant, a preparation method, application and a sewage treatment method. The coagulant is composed of hydroxyethyl cellulose and konjac gum, and the mass ratio of the hydroxyethyl cellulose and the konjac gum in the coagulant is (0.01-0.15):0.05. The coagulant of the application generates no toxic by-products after water treatment, has no toxic and harmful effects on the human body and an ecological system, has small environmental pollution, and the composed coagulant can better cooperate with a flocculant to treat carbon-containing sewage, can also treat sewage with large sludge specific resistance, and realizes the synergistic effect of sewage treatment and water quality safety.

Description

Technical Field

[0001] This application relates to the field of water treatment technology, and more specifically, to a polymeric composite water treatment coagulant, its preparation method, its application, and a wastewater treatment method. Background Technology

[0002] In recent years, with the increasing demands for drinking water quality, coagulation technology has become increasingly important in the field of drinking water treatment. There is a growing demand for efficient and environmentally friendly coagulants to meet future requirements for higher effluent quality and ensure drinking water safety. Traditional coagulants, such as polyacrylamide (PAM), polysilicic acid, bone glue, and sodium alginate, all have certain limitations. In particular, PAM, the most widely used, is expensive and may contain residual acrylamide monomers, a neurotoxin, in the treated water, posing a certain degree of toxicity to humans and impacting the ecological environment. The synthesis of polysilicic acid requires high temperatures and strong acids and alkalis, easily causing secondary pollution. While naturally extracted coagulants such as bone glue and sodium alginate are non-toxic, their extraction processes are complex, involving strong acids, strong alkalis, and substances like benzene, which can easily pollute the environment. Sludge thickening is a crucial step in water supply and wastewater treatment, and the added chemicals are key to improving thickening efficiency. Currently, polyacrylamide (PAM), polyaluminum chloride (PAC), and ferric chloride are mainly added. Using these coagulants may cause secondary pollution problems and is corrosive, which can easily damage water treatment equipment and pipelines, increasing maintenance and replacement costs. Summary of the Invention

[0003] This application addresses the aforementioned deficiencies in the prior art. There is a need for a polymeric composite coagulant aid for water treatment, its preparation method, its application, and a wastewater treatment method, which can replace the existing water treatment agent PAM, solve the problems of residual toxic substances in water after the use of PAM coagulant aid and the secondary pollution easily caused by its synthesis, and also have a better coagulant aid effect.

[0004] In a first aspect, this application provides a polymeric composite water treatment coagulant aid composed of hydroxyethyl cellulose and konjac gum, wherein the mass ratio of hydroxyethyl cellulose to konjac gum in the coagulant aid is (0.01-0.15):0.05.

[0005] A second aspect of this application provides a method for preparing the coagulant aid described in any embodiment of this application, the method comprising: mixing the hydroxyethyl cellulose and konjac gum with water to obtain the coagulant aid.

[0006] A third aspect of this application provides the application of the coagulant aid described in any embodiment of this application in wastewater treatment.

[0007] A fourth aspect of this application provides a method for treating wastewater containing organic carbon. The method includes: adding a flocculant to the wastewater while it is being stirred, then adding the coagulant aid described in any embodiment of this application, stirring, and allowing it to settle. The settled wastewater is then subjected to solid-liquid separation to obtain treated water. The wastewater has a sludge specific resistance of less than 0.5 × 10⁻⁶. 8 s 2 / g of wastewater, and the TOC in the wastewater is greater than 3 mg / L.

[0008] A fifth aspect of this application provides a method for treating wastewater from a sludge thickening tank. The method includes adding the coagulant aid described in any embodiment of this application to the wastewater, stirring, and then allowing it to stand. The wastewater includes sludge discharge water from a reaction tank, sludge discharge water from a sedimentation tank, and / or backwash wastewater from a filter.

[0009] The various embodiments of this application provide a polymeric composite water treatment coagulant, preparation method, application, and wastewater treatment method. The coagulant includes hydroxyethyl cellulose and konjac gum, with a mass ratio of hydroxyethyl cellulose to konjac gum of (0.01-0.15):0.05. Both hydroxyethyl cellulose and konjac gum are natural polymeric materials with low residual risk. They produce no toxic byproducts after water treatment, have no toxic effects on humans and ecosystems, and cause minimal environmental pollution. Furthermore, the coagulant composition can effectively synergistically treat carbon-containing wastewater with flocculants and can also treat wastewater with high sludge resistance, achieving a synergistic effect of wastewater treatment and water quality safety. Attached Figure Description

[0010] In drawings that are not necessarily drawn to scale, the same reference numerals may describe similar parts in different views. The same reference numerals with or without letter suffixes may indicate different instances of similar parts. The drawings generally illustrate various embodiments by way of example rather than limitation and are used, together with the description and claims, to illustrate the claimed embodiments. Where appropriate, the same reference numerals are used in all drawings to refer to the same or similar parts. Such embodiments are illustrative and not intended to be exhaustive or exclusive embodiments of the apparatus or method.

[0011] Figure 1 A comparison graph showing the bacterial growth inhibition rate according to Experimental Example 1 of this application is provided.

[0012] Figure 2 This paper shows a comparison chart of wastewater turbidity removal according to different embodiments of this application;

[0013] Figure 3 Comparative diagrams of UV254 according to different embodiments of this application are shown;

[0014] Figure 4The diagram shows a comparison of TOC removal according to different embodiments of this application. Detailed Implementation

[0015] To enable those skilled in the art to better understand the technical solutions of this application, the application will be described in detail below with reference to the accompanying drawings and specific embodiments. The embodiments of this application will be further described in detail below with reference to the accompanying drawings and specific examples, but these are not intended to limit the scope of this application.

[0016] The terms “first,” “second,” and similar terms used in this application do not indicate any order, quantity, or importance, but are merely used for distinction. Terms such as “including” or “comprising” mean that the element preceding the term covers the element listed after the term, and do not exclude the possibility of covering other elements as well.

[0017] According to an embodiment of this application, a polymeric composite water treatment coagulant is provided, the coagulant comprising hydroxyethyl cellulose and konjac gum, wherein the mass ratio of hydroxyethyl cellulose to konjac gum in the coagulant is (0.01-0.15):0.05.

[0018] Konjac gum is extracted from the root tuber of the natural plant konjac, and its main component is glucosan. Hydroxyethyl cellulose (HEC) is a food additive, and its use in drinking water complies with the requirements of GB 2760 01.06 standard. Konjac gum (KGM) is also a food additive, and its use in drinking water complies with the requirements of Q / TXDS 0009 S-2022 standard. Both hydroxyethyl cellulose and konjac gum are natural polymer materials, with simple extraction processes, low consumption of chemical reagents, and minimal environmental pollution. When used in wastewater treatment, they offer advantages such as being green and safe, having low residue risk, and producing no toxic byproducts. They are also relatively inexpensive. Therefore, their application aligns with the concept of sustainable development.

[0019] The coagulant formed by hydroxyethyl cellulose and konjac gum mainly utilizes adsorption bridging and trapping effects. When combined with the flocculant polyaluminum chloride to treat water samples, the resulting flocs are large in volume and have a fast sedimentation rate, which can remove impurities and organic pollutants from wastewater.

[0020] The coagulant formed by hydroxyethyl cellulose and konjac gum mainly utilizes adsorption bridging to adsorb onto the surface of colloidal particles and form a bridging structure through intermolecular interactions, resulting in denser and stronger flocs. Furthermore, it utilizes netting to promote particle aggregation, improve sludge settling, enhance sludge dewatering performance, and reduce sludge volume in subsequent treatment processes.

[0021] The mass ratio of hydroxyethyl cellulose (HEC) to konjac gum is (0.01-0.15):0.05. Within this range, the coagulant formed by HEC and konjac gum can fully exert their respective treatment effects. Experiments have shown that the preferred mass ratio of HEC to konjac gum is (0.07-0.15):0.05 or (0.04-0.06):0.05. Exceeding this range is detrimental to improving the coagulant's effectiveness. HEC and konjac gum are chemical substances with different properties and play different roles in the coagulant. Their ratio affects the synergistic effect and, consequently, the wastewater treatment efficiency.

[0022] In some embodiments, the coagulant further includes water, and the coagulant composed of water, hydroxyethyl cellulose, and konjac gum is a transparent liquid, wherein the concentration of hydroxyethyl cellulose in the coagulant is 0.1-1.5 g / L. Preferably, the concentration of hydroxyethyl cellulose in the coagulant is 0.7-1.5 g / L.

[0023] The pure water includes ultrapure water, deionized water, distilled water, and water with a conductivity of less than 0.1.

[0024] According to an embodiment of this application, a method for preparing the coagulant aid described in any embodiment of this application is also provided. The preparation method includes: mixing the hydroxyethyl cellulose and konjac gum with water to obtain the coagulant aid.

[0025] According to embodiments of this application, the application of the coagulant aid described in any embodiment of this application in wastewater treatment is also provided.

[0026] According to embodiments of this application, a method for treating wastewater containing organic carbon is also provided. The method includes: adding a flocculant to the wastewater while it is being stirred, then adding the coagulant aid described in any embodiment of this application, stirring, and allowing it to settle. The settled wastewater is then subjected to solid-liquid separation to obtain treated water. The wastewater has a sludge specific resistance of less than 0.5 × 10⁻⁶. 8 s 2 / g of wastewater, and the TOC in the wastewater is greater than 3 mg / L.

[0027] Wastewater containing organic carbon is wastewater with a low sludge content but a high level of organic pollutants, such as lake water and river water. First, a flocculant is added to the wastewater containing organic carbon, followed by a coagulant aid. After the flocculant interacts with the pollutants in the wastewater, it is allowed to settle, and solid-liquid separation is achieved to obtain treated water.

[0028] In some embodiments, the dosage of hydroxyethyl cellulose in the coagulant is 0.1-1.5 mg / L relative to wastewater. This is equivalent to adding 0.1-1.5 mg of hydroxyethyl cellulose per 1 L of wastewater. Preferably, the dosage of hydroxyethyl cellulose is 0.7-1.5 mg / L.

[0029] In some embodiments, the flocculant is polyaluminum chloride. Both polyaluminum chloride and polyferric sulfate (PFS) are flocculants, and their flocculation effects are comparable. However, the synergistic effect of these two substances with the coagulant aid of this application differs. When treating wastewater, polyaluminum chloride and the coagulant aid of this application can form larger flocs, resulting in faster sedimentation and better treatment effects.

[0030] In wastewater treatment, flocculants are added before and after the wastewater is stirred; alternatively, flocculants are added after stirring is complete, followed by the addition of the coagulant aid; or flocculants are added first, then stirred, and finally added after stirring is complete. Experiments have shown that adding flocculants and coagulant aids simultaneously prevents the rapid formation and growth of alum flocs, thus hindering sedimentation and the removal of impurities from the water. However, if flocculants are added first, followed by the coagulant aid, larger alum flocs form rapidly and settle quickly.

[0031] In some embodiments, the stirring of the wastewater includes rapid stirring, medium-speed stirring, and slow stirring in sequence, with the stirring speed decreasing sequentially from rapid stirring to medium-speed stirring to slow stirring. Specifically, flocculants are added during rapid stirring, coagulant aids are added during medium-speed stirring, and the mixture is allowed to stand after slow stirring.

[0032] In some embodiments, the agitation of the wastewater sequentially includes rapid agitation for 30-60 seconds, medium-speed agitation for 1-2 minutes, and slow agitation for 10-15 minutes, wherein the speed of rapid agitation is 250-350 r, the speed of medium-speed agitation is 100-200 r, and the speed of slow agitation is 30-50 r. Rapid agitation is beneficial for sedimentation, while excessively fast water flow will break up existing flocs, hindering sedimentation. Rapid agitation helps the flocculant react fully with impurities in the water and coagulate, while slow agitation and stillness promote sedimentation.

[0033] According to an embodiment of this application, a method for treating wastewater from a sludge thickening tank is also provided. The method includes adding the coagulant aid described in any embodiment of this application to the wastewater, stirring, and then allowing it to stand. The wastewater includes sludge discharge water from a reaction tank, sludge discharge water from a sedimentation tank, and / or backwash wastewater from a filter.

[0034] The coagulant aid of this application can adsorb onto the surface of colloidal particles through its adsorption bridging effect and form a bridging structure through intermolecular interactions, which helps the flocculant form denser and stronger flocs. It also promotes particle aggregation through the net-trapping effect, improves sludge settling efficiency, helps improve sludge dewatering performance, and reduces sludge volume in subsequent treatment processes.

[0035] In some embodiments, the pH of the wastewater is 7.5-9.0; the temperature of the wastewater is 20-25 °C.

[0036] In some embodiments, the dosage of hydroxyethyl cellulose in the coagulant is 0.1-0.8 mg / L relative to wastewater. Preferably, the dosage of hydroxyethyl cellulose in the coagulant is 0.4-0.6 mg / L relative to wastewater. For example, 0.4 mg / L, 0.5 mg / L, and 0.6 mg / L.

[0037] Example 1

[0038] An enhanced coagulation method using hydroxyethyl cellulose (HEC) and konjac gum as coagulants. The hydroxyethyl cellulose (HEC) meets the requirements of GB2760 01.06 standard, and the konjac gum (KGM) meets the requirements of Q / TXDS 0009 S-2022 standard.

[0039] 0.01 g of hydroxyethyl cellulose and 0.05 g of konjac gum were combined and added to 100 mL of ultrapure water to prepare an aqueous solution with an HEC concentration of 0.10 g / L.

[0040] Water source conditions: Lake water in Jinan City, Shandong Province; raw water turbidity: 6.60 NTU; raw water absorbance at UV254 using a UV spectrophotometer: 0.078 cm⁻¹ -1 The TOC of the raw water is 3.58 mg / L.

[0041] Instructions for use: The coagulation process employs a three-stage stirring method: rapid stirring, medium-speed stirring, and slow stirring. The selected stirring times are: rapid stirring 250 rpm for 30 seconds, medium-speed stirring 200 rpm for 1 minute, and slow stirring 50 rpm for 15 minutes. During rapid stirring, the flocculant (polyaluminum chloride) is added at a dosage of 50 mg / L. The product is diluted with the water sample at a concentration ratio of 1:1000 (i.e., 1 mL of a 0.10 g / L HEC composite solution is added to 1 L of raw water sample). The diluted coagulant aid is added 1 minute after the flocculant addition (i.e., during medium-speed stirring), with a final HEC dosage of 0.10 mg / L. After slow stirring, the water sample is allowed to stand for 30 minutes before testing.

[0042] Results: In the water sample without HEC composite KGM (i.e., after adding the flocculant but before adding the coagulant aid), the turbidity decreased from 6.60 NTU to 4.83 NTU, and the absorbance at UV254 decreased from 0.078 cm⁻¹. -1 Decreased to 0.065 cm -1TOC decreased from 3.58 mg / L to 3.12 mg / L. The formed flocs were smaller, and the sedimentation rate was slower. The turbidity of the water sample after adding HEC compound KGM decreased from 6.60 NTU to 4.53 NTU, and the absorbance at UV254 decreased from 0.078 cm⁻¹. -1 It decreased to 0.057 cm. -1 TOC decreased from 3.58 mg / L to 2.87 mg / L. The formed flocs were larger, and the precipitation rate was faster.

[0043] Example 2

[0044] An enhanced coagulation method using hydroxyethyl cellulose (HEC) and konjac gum as coagulants. The hydroxyethyl cellulose (HEC) meets the requirements of GB2760 01.06 standard, and the konjac gum (KGM) meets the requirements of Q / TXDS 0009 S-2022 standard.

[0045] 0.03 g of hydroxyethyl cellulose and 0.05 g of konjac gum were combined and added to 100 mL of ultrapure water to prepare an aqueous solution with an HEC concentration of 0.30 g / L.

[0046] Water source conditions: Lake water in Jinan City, Shandong Province; raw water turbidity: 6.60 NTU; raw water absorbance at UV254 using a UV spectrophotometer: 0.078 cm⁻¹ -1 The TOC of the raw water is 3.58 mg / L.

[0047] Usage: The coagulation process employs a three-stage stirring method: rapid stirring, medium-speed stirring, and slow stirring. The selected stirring times are: rapid stirring 250 rpm for 30 seconds, medium-speed stirring 200 rpm for 1 minute, and slow stirring 50 rpm for 15 minutes. Flocculant (polyaluminum chloride) is added during rapid stirring. The raw water quality conditions and flocculant dosage are the same as in Example 1. The product is diluted with the water sample at a concentration ratio of 1:1000 (i.e., 1 mL of a 0.30 g / L HEC composite solution is added to 1 L of raw water sample). The diluted coagulant aid is added 1 minute after the flocculant addition (i.e., during medium-speed stirring), with a final HEC dosage of 0.30 mg / L. After slow stirring, the water sample is allowed to stand for 30 minutes before testing.

[0048] Results: In the water sample without HEC composite KGM (i.e., after adding the flocculant but before adding the coagulant aid), the turbidity decreased from 6.60 NTU to 4.83 NTU, and the absorbance at UV254 decreased from 0.078 cm⁻¹. -1 Decreased to 0.065 cm -1TOC decreased from 3.58 mg / L to 3.12 mg / L. The formed flocs were smaller, and the sedimentation rate was slower. The turbidity of the water sample after adding HEC compound KGM decreased from 6.60 NTU to 2.34 NTU, and the absorbance at UV254 decreased from 0.078 cm⁻¹. -1 Decreased to 0.051 cm -1 TOC decreased from 3.58 mg / L to 2.65 mg / L. The formed flocs were larger, and the precipitation rate was faster.

[0049] Example 3

[0050] An enhanced coagulation method using hydroxyethyl cellulose (HEC) and konjac gum as coagulants. The hydroxyethyl cellulose (HEC) meets the requirements of GB2760 01.06 standard, and the konjac gum (KGM) meets the requirements of Q / TXDS 0009 S-2022 standard.

[0051] 0.05 g of hydroxyethyl cellulose and 0.05 g of konjac gum were combined and added to 100 mL of ultrapure water to prepare an aqueous solution with an HEC concentration of 0.50 g / L.

[0052] Water source conditions: Lake water in Jinan City, Shandong Province; raw water turbidity: 6.60 NTU; raw water absorbance at UV254 using a UV spectrophotometer: 0.078 cm⁻¹ -1 The TOC of the raw water is 3.58 mg / L.

[0053] Usage: The coagulation process employs a three-stage stirring method: rapid stirring, medium-speed stirring, and slow stirring. The selected stirring times are: rapid stirring 250 rpm for 30 seconds, medium-speed stirring 200 rpm for 1 minute, and slow stirring 50 rpm for 15 minutes. Flocculant (polyaluminum chloride) is added during rapid stirring. The raw water quality conditions and flocculant dosage are the same as in Example 1. The product is diluted with the water sample at a concentration ratio of 1:1000 (i.e., 1 mL of a 0.50 g / L HEC composite solution is added to 1 L of raw water sample). The diluted coagulant aid is added 1 minute after the flocculant addition (i.e., during medium-speed stirring), with a final HEC dosage of 0.50 mg / L. After slow stirring, the water sample is allowed to stand for 30 minutes before testing.

[0054] Results: In the water sample without HEC composite KGM (i.e., after adding the flocculant but before adding the coagulant aid), the turbidity decreased from 6.60 NTU to 4.83 NTU, and the absorbance at UV254 decreased from 0.078 cm⁻¹. -1 Decreased to 0.065 cm -1TOC decreased from 3.58 mg / L to 3.12 mg / L. The formed flocs were smaller, and the sedimentation rate was slower. The turbidity of the water sample after adding HEC compound KGM decreased from 6.60 NTU to 2.01 NTU, and the absorbance at UV254 decreased from 0.078 cm⁻¹. -1 Decreased to 0.043 cm -1 TOC decreased from 3.58 mg / L to 2.48 mg / L. The formed flocs were larger, and the precipitation rate was faster.

[0055] Example 4

[0056] An enhanced coagulation method using hydroxyethyl cellulose (HEC) and konjac gum as coagulants. The hydroxyethyl cellulose (HEC) meets the requirements of GB2760 01.06 standard, and the konjac gum (KGM) meets the requirements of Q / TXDS 0009 S-2022 standard.

[0057] 0.07 g of hydroxyethyl cellulose and 0.05 g of konjac gum were combined and added to 100 mL of ultrapure water to prepare an aqueous solution with an HEC concentration of 0.70 g / L.

[0058] Water source conditions: Lake water in Jinan City, Shandong Province; raw water turbidity: 6.60 NTU; raw water absorbance at UV254 using a UV spectrophotometer: 0.078 cm⁻¹ -1 The TOC of the raw water is 3.58 mg / L.

[0059] Usage: The coagulation process employs a three-stage stirring method: rapid stirring, medium-speed stirring, and slow stirring. The selected stirring times are: rapid stirring 250 rpm for 30 seconds, medium-speed stirring 200 rpm for 1 minute, and slow stirring 50 rpm for 15 minutes. Flocculant (polyaluminum chloride) is added during rapid stirring. The raw water quality conditions and flocculant dosage are the same as in Example 1. The product is diluted with the water sample at a concentration ratio of 1:1000 (i.e., 1 mL of a 0.70 g / L HEC composite solution is added to 1 L of raw water sample). The diluted coagulant aid is added 1 minute after the flocculant addition (i.e., during medium-speed stirring), with a final HEC dosage of 0.70 mg / L. After slow stirring, the water sample is allowed to stand for 30 minutes before testing.

[0060] Results: In the water sample without HEC composite KGM (i.e., after adding the flocculant but before adding the coagulant aid), the turbidity decreased from 6.60 NTU to 4.83 NTU, and the absorbance at UV254 decreased from 0.078 cm⁻¹. -1 Decreased to 0.065 cm -1TOC decreased from 3.58 mg / L to 3.12 mg / L. The formed flocs were smaller, and the sedimentation rate was slower. The turbidity of the water sample after adding HEC compound KGM decreased from 6.60 NTU to 1.91 NTU, and the absorbance at UV254 decreased from 0.078 cm⁻¹. -1 Decreased to 0.045 cm -1 TOC decreased from 3.58 mg / L to 2.21 mg / L. The formed flocs were larger, and the precipitation rate was faster.

[0061] Example 5

[0062] An enhanced coagulation method using hydroxyethyl cellulose (HEC) and konjac gum as coagulants. The hydroxyethyl cellulose (HEC) meets the requirements of GB2760 01.06 standard, and the konjac gum (KGM) meets the requirements of Q / TXDS 0009 S-2022 standard.

[0063] 0.09 g of hydroxyethyl cellulose and 0.05 g of konjac gum were combined and added to 100 mL of ultrapure water to prepare an aqueous solution with an HEC concentration of 0.90 g / L.

[0064] Water source conditions: Lake water in Jinan City, Shandong Province; raw water turbidity: 6.60 NTU; raw water absorbance at UV254 using a UV spectrophotometer: 0.078 cm⁻¹ -1 The TOC of the raw water is 3.58 mg / L.

[0065] Usage: The coagulation process employs a three-stage stirring method: rapid stirring, medium-speed stirring, and slow stirring. The selected stirring times are: rapid stirring 250 rpm for 30 seconds, medium-speed stirring 200 rpm for 1 minute, and slow stirring 50 rpm for 15 minutes. Flocculant (polyaluminum chloride) is added during rapid stirring. The raw water quality conditions and flocculant dosage are the same as in Example 1. The product is diluted with the water sample at a concentration ratio of 1:1000 (i.e., 1 mL of a 0.90 g / L HEC composite solution is added to 1 L of raw water sample). The diluted coagulant aid is added 1 minute after the flocculant addition (i.e., during medium-speed stirring), with a final HEC dosage of 0.90 mg / L. After slow stirring, the water sample is allowed to stand for 30 minutes before testing.

[0066] Results: In the water sample without HEC composite KGM (i.e., after adding the flocculant but before adding the coagulant aid), the turbidity decreased from 6.60 NTU to 4.83 NTU, and the absorbance at UV254 decreased from 0.078 cm⁻¹. -1 Decreased to 0.065 cm -1TOC decreased from 3.58 mg / L to 3.12 mg / L. The formed flocs were smaller, and the sedimentation rate was slower. The turbidity of the water sample after adding HEC compound KGM decreased from 6.60 NTU to 1.63 NTU, and the absorbance at UV254 decreased from 0.078 cm⁻¹. -1 It decreased to 0.042 cm. -1 TOC decreased from 3.58 mg / L to 2.02 mg / L. The formed flocs were larger, and the precipitation rate was faster.

[0067] Example 6

[0068] An enhanced coagulation method using hydroxyethyl cellulose (HEC) and konjac gum as coagulants. The hydroxyethyl cellulose (HEC) meets the requirements of GB2760 01.06 standard, and the konjac gum (KGM) meets the requirements of Q / TXDS 0009 S-2022 standard.

[0069] 0.10 g of hydroxyethyl cellulose and 0.05 g of konjac gum were combined and added to 100 mL of ultrapure water to prepare an aqueous solution with an HEC concentration of 1.00 g / L.

[0070] Water source conditions: Lake water in Jinan City, Shandong Province; raw water turbidity: 6.60 NTU; raw water absorbance at UV254 using a UV spectrophotometer: 0.078 cm⁻¹ -1 The TOC of the raw water is 3.58 mg / L.

[0071] Usage: The coagulation process employs a three-stage stirring method: rapid stirring, medium-speed stirring, and slow stirring. The selected stirring times are: rapid stirring 250 rpm for 30 seconds, medium-speed stirring 200 rpm for 1 minute, and slow stirring 50 rpm for 15 minutes. Flocculant (polyaluminum chloride) is added during rapid stirring. The raw water quality conditions and flocculant dosage are the same as in Example 1. The product is diluted with the water sample at a concentration ratio of 1:1000 (i.e., 1 mL of a 1.00 g / L HEC composite solution is added to 1 L of raw water sample). The diluted coagulant aid is added 1 minute after the flocculant addition (i.e., during medium-speed stirring), with a final HEC dosage of 1.00 mg / L. After slow stirring, the water sample is allowed to stand for 30 minutes before testing.

[0072] Results: In the water sample without HEC composite KGM (i.e., after adding the flocculant but before adding the coagulant aid), the turbidity decreased from 6.60 NTU to 4.83 NTU, and the absorbance at UV254 decreased from 0.078 cm⁻¹. -1 Decreased to 0.065 cm -1TOC decreased from 3.58 mg / L to 3.12 mg / L. The formed flocs were smaller, and the sedimentation rate was slower. The turbidity of the water sample after adding HEC compound KGM decreased from 6.60 NTU to 1.51 NTU, and the absorbance at UV254 decreased from 0.078 cm⁻¹. -1 Decreased to 0.041 cm -1 TOC decreased from 3.58 mg / L to 1.89 mg / L. The formed flocs were relatively large, and the precipitation rate was relatively fast.

[0073] Example 7

[0074] An enhanced coagulation method using hydroxyethyl cellulose (HEC) and konjac gum as coagulants. The hydroxyethyl cellulose (HEC) meets the requirements of GB2760 01.06 standard, and the konjac gum (KGM) meets the requirements of Q / TXDS 0009 S-2022 standard.

[0075] 0.11 g of hydroxyethyl cellulose and 0.05 g of konjac gum were combined and added to 100 mL of ultrapure water to prepare an aqueous solution with an HEC concentration of 1.10 g / L.

[0076] Water source conditions: Lake water in Jinan City, Shandong Province; raw water turbidity: 6.60 NTU; raw water absorbance at UV254 using a UV spectrophotometer: 0.078 cm⁻¹ -1 The TOC of the raw water is 3.58 mg / L.

[0077] Usage: The coagulation process employs a three-stage stirring method: rapid stirring, medium-speed stirring, and slow stirring. The selected stirring times are: rapid stirring 250 rpm for 30 seconds, medium-speed stirring 200 rpm for 1 minute, and slow stirring 50 rpm for 15 minutes. Flocculant (polyaluminum chloride) is added during rapid stirring. The raw water quality conditions and flocculant dosage are the same as in Example 1. The product is diluted with the water sample at a concentration ratio of 1:1000 (i.e., 1 mL of a 1.10 g / L HEC composite solution is added to 1 L of raw water sample). The diluted coagulant aid is added 1 minute after the flocculant addition (i.e., during medium-speed stirring), with a final HEC dosage of 1.10 mg / L. After slow stirring, the water sample is allowed to stand for 30 minutes before testing.

[0078] Results: In the water sample without HEC composite KGM (i.e., after adding the flocculant but before adding the coagulant aid), the turbidity decreased from 6.60 NTU to 4.83 NTU, and the absorbance at UV254 decreased from 0.078 cm⁻¹. -1 Decreased to 0.065 cm -1TOC decreased from 3.58 mg / L to 3.12 mg / L. The formed flocs were smaller, and the sedimentation rate was slower. The turbidity of the water sample after adding HEC compound KGM decreased from 6.60 NTU to 1.47 NTU, and the absorbance at UV254 decreased from 0.078 cm⁻¹. -1 Decreased to 0.043 cm -1 TOC decreased from 3.58 mg / L to 1.93 mg / L. The formed flocs were larger, and the precipitation rate was faster.

[0079] Example 8

[0080] An enhanced coagulation method using hydroxyethyl cellulose (HEC) and konjac gum as coagulants. The hydroxyethyl cellulose (HEC) meets the requirements of GB2760 01.06 standard, and the konjac gum (KGM) meets the requirements of Q / TXDS 0009 S-2022 standard.

[0081] 0.13 g of hydroxyethyl cellulose and 0.05 g of konjac gum were combined and added to 100 mL of ultrapure water to prepare an aqueous solution with an HEC concentration of 1.30 g / L.

[0082] Water source conditions: Lake water in Jinan City, Shandong Province; raw water turbidity: 6.60 NTU; raw water absorbance at UV254 using a UV spectrophotometer: 0.078 cm⁻¹ -1 The TOC of the raw water is 3.58 mg / L.

[0083] Usage: The coagulation process employs a three-stage stirring method: rapid stirring, medium-speed stirring, and slow stirring. The selected stirring times are: rapid stirring 300 rpm for 30 seconds, medium-speed stirring 150 rpm for 1 minute, and slow stirring 30 rpm for 15 minutes. Flocculant (polyaluminum chloride) is added during rapid stirring. The raw water quality conditions and flocculant dosage are the same as in Example 1. The product is diluted with the water sample at a concentration ratio of 1:1000 (i.e., 1 mL of a 1.30 g / L HEC composite solution is added to 1 L of raw water sample). The diluted coagulant aid is added 1 minute after the flocculant addition (i.e., during medium-speed stirring), with a final HEC dosage of 1.30 mg / L. After slow stirring, the water sample is allowed to stand for 30 minutes before testing.

[0084] Results: In the water sample without HEC composite KGM (i.e., after adding the flocculant but before adding the coagulant aid), the turbidity decreased from 6.60 NTU to 4.83 NTU, and the absorbance at UV254 decreased from 0.078 cm⁻¹. -1 Decreased to 0.065 cm -1TOC decreased from 3.58 mg / L to 3.12 mg / L. The formed flocs were smaller, and the sedimentation rate was slower. The turbidity of the water sample after adding HEC compound KGM decreased from 6.60 NTU to 1.24 NTU, and the absorbance at UV254 decreased from 0.078 cm⁻¹. -1 It decreased to 0.048 cm. -1 TOC decreased from 3.58 mg / L to 2.01 mg / L. The formed flocs were relatively large, and the precipitation rate was relatively fast.

[0085] Example 9

[0086] An enhanced coagulation method using hydroxyethyl cellulose (HEC) and konjac gum as coagulants. The hydroxyethyl cellulose (HEC) meets the requirements of GB2760 01.06 standard, and the konjac gum (KGM) meets the requirements of Q / TXDS 0009 S-2022 standard.

[0087] 0.15 g of hydroxyethyl cellulose and 0.05 g of konjac gum were combined and added to 100 mL of ultrapure water to prepare an aqueous solution with an HEC concentration of 1.50 g / L.

[0088] Water source conditions: Lake water in Jinan City, Shandong Province; raw water turbidity: 6.60 NTU; raw water absorbance at UV254 using a UV spectrophotometer: 0.078 cm⁻¹ -1 The TOC of the raw water is 3.58 mg / L.

[0089] Usage: The coagulation process employs a three-stage stirring method: rapid stirring, medium-speed stirring, and slow stirring. The selected stirring times are: rapid stirring 300 rpm for 30 seconds, medium-speed stirring 150 rpm for 1 minute, and slow stirring 30 rpm for 15 minutes. Flocculant (polyaluminum chloride) is added during rapid stirring. The raw water quality conditions and flocculant dosage are the same as in Example 1. The product is diluted with the water sample at a concentration ratio of 1:1000 (i.e., 1 mL of a 1.50 g / L HEC composite solution is added to 1 L of raw water sample). The diluted coagulant aid is added 1 minute after the flocculant addition (i.e., during medium-speed stirring), with a final HEC dosage of 1.50 mg / L. After slow stirring, the water sample is allowed to stand for 30 minutes before testing.

[0090] Results: In the water sample without HEC composite KGM (i.e., after adding the flocculant but before adding the coagulant aid), the turbidity decreased from 6.60 NTU to 4.83 NTU, and the absorbance at UV254 decreased from 0.078 cm⁻¹. -1 Decreased to 0.065 cm -1TOC decreased from 3.58 mg / L to 3.12 mg / L. The formed flocs were smaller, and the sedimentation rate was slower. The turbidity of the water sample after adding HEC compound KGM decreased from 6.60 NTU to 1.04 NTU, and the absorbance at UV254 decreased from 0.078 cm⁻¹. -1 Decreased to 0.051 cm -1 TOC decreased from 3.58 mg / L to 2.23 mg / L. The formed flocs were larger, and the precipitation rate was faster.

[0091] Example 10

[0092] An enhanced coagulation method using hydroxyethyl cellulose (HEC) and konjac gum as coagulants. The hydroxyethyl cellulose (HEC) meets the requirements of GB2760 01.06 standard, and the konjac gum (KGM) meets the requirements of Q / TXDS 0009 S-2022 standard.

[0093] 0.17 g of hydroxyethyl cellulose and 0.05 g of konjac gum were combined and added to 100 mL of ultrapure water to prepare an aqueous solution with an HEC concentration of 1.70 g / L.

[0094] Water source conditions: Lake water in Jinan City, Shandong Province; raw water turbidity: 6.60 NTU; raw water absorbance at UV254 using a UV spectrophotometer: 0.078 cm⁻¹ -1 The TOC of the raw water is 3.58 mg / L.

[0095] Usage: The coagulation process employs a three-stage stirring method: rapid stirring, medium-speed stirring, and slow stirring. The selected stirring times are: rapid stirring 300 rpm for 30 seconds, medium-speed stirring 150 rpm for 1 minute, and slow stirring 30 rpm for 15 minutes. Flocculant (polyaluminum chloride) is added during rapid stirring. The raw water quality conditions and flocculant dosage are the same as in Example 1. The product is diluted with the water sample at a concentration ratio of 1:1000 (i.e., 1 mL of a 1.70 g / L HEC composite solution is added to 1 L of raw water sample). The diluted coagulant aid is added 1 minute after the flocculant addition (i.e., during medium-speed stirring), with a final HEC dosage of 1.70 mg / L. After slow stirring, the water sample is allowed to stand for 30 minutes before testing.

[0096] Results: In the water sample without HEC composite KGM (i.e., after adding the flocculant but before adding the coagulant aid), the turbidity decreased from 6.60 NTU to 4.83 NTU, and the absorbance at UV254 decreased from 0.078 cm⁻¹. -1 Decreased to 0.065 cm -1TOC decreased from 3.58 mg / L to 3.12 mg / L. The formed flocs were smaller, and the sedimentation rate was slower. The turbidity of the water sample after adding HEC compound KGM decreased from 6.60 NTU to 1.01 NTU, and the absorbance at UV254 decreased from 0.078 cm⁻¹. -1 It dropped to 0.055cm -1 TOC decreased from 3.58 mg / L to 2.47 mg / L. The formed flocs were larger, and the precipitation rate was faster.

[0097] In Examples 1-10, large flocs were formed during wastewater treatment, resulting in rapid sedimentation. Compared to treatment without coagulant, this significantly reduced turbidity and removed impurities and organic pollutants from the water samples. However, Examples 4-9 showed better TOC removal compared to Examples 1, 2, and 10. This indicates that only the ratio of hydroxyethyl cellulose (HEC) to konjac gum and the dosage of HEC can affect the degree of TOC removal from wastewater.

[0098] Example 11

[0099] A method for using hydroxyethyl cellulose (HEC) and konjac gum as a sludge thickening and coagulant aid. It is mainly applied in sludge thickening tanks in water supply and drainage treatment processes to treat sludge discharge from reaction tanks, sedimentation tanks, and filter backwash wastewater. Hydroxyethyl cellulose (HEC) meets the requirements of GB 2760 01.06 standard, and konjac gum (KGM) meets the requirements of Q / TXDS 0009 S-2022 standard.

[0100] 0.02 g of hydroxyethyl cellulose and 0.05 g of konjac gum were combined and added to 100 mL of ultrapure water to prepare an aqueous solution with an HEC concentration of 0.20 g / L.

[0101] Water source conditions: A water treatment plant in Jinan City, Shandong Province; water source: sludge discharge from the water plant, with a water content of 99.35%. The specific resistance of the sludge without flocculant was measured to be 1.09 × 10⁻⁶. 9 s 2 / g, belonging to the category of sludge that is difficult to mechanically concentrate. The invented product was diluted with the water sample at a concentration ratio of 1:1000 (that is, 1 mL of HEC composite solution with a concentration of 0.20 g / L was added to 1L of raw water sample), and the final HEC dosage was 0.20 mg / L.

[0102] Results: Compared to before adding the coagulant aid, the water sample with added HEC composite KGM showed a decrease in moisture content from 99.35% to 97.78%, and a decrease in sludge specific resistance from 1.09 × 10⁻⁶. 9 s 2 / g decreased to 5.62×10 8 s2 / g, mud-water separation interface height 270 mm (liquid level 500 mm). The supernatant is relatively clear, and the sludge flocs are aggregated into clumps.

[0103] Example 12

[0104] A method for using hydroxyethyl cellulose (HEC) and konjac gum as a sludge thickening and coagulant aid. It is mainly applied in sludge thickening tanks in water supply and drainage treatment processes to treat sludge discharge from reaction tanks, sedimentation tanks, and filter backwash wastewater. Hydroxyethyl cellulose (HEC) meets the requirements of GB 2760 01.06 standard, and konjac gum (KGM) meets the requirements of Q / TXDS 0009 S-2022 standard.

[0105] 0.04 g of hydroxyethyl cellulose and 0.05 g of konjac gum were combined and added to 100 mL of ultrapure water to prepare an aqueous solution with an HEC concentration of 0.40 g / L.

[0106] Water source conditions: A water treatment plant in Jinan City, Shandong Province; water source: sludge discharge from the water plant, with a water content of 99.35%. The specific resistance of the sludge without flocculant was measured to be 1.09 × 10⁻⁶. 9 s 2 / g, belonging to the category of sludge that is difficult to mechanically thicken. The invented product was diluted with the water sample at a concentration ratio of 1:1000 (that is, 1 mL of HEC composite solution with a concentration of 0.40 g / L was added to 1L of raw water sample), and the final HEC dosage was 0.40 mg / L.

[0107] Results: Compared to before adding the coagulant, the water sample with added HEC composite KGM showed a decrease in moisture content from 99.35% to 96.13%, and a decrease in sludge specific resistance from 1.09 × 10⁻⁶. 9 s 2 / g decreased to 2.62×10 8 s 2 / g, mud-water separation interface height 240 mm (liquid level 500 mm). The supernatant is relatively clear, and the sludge flocs are aggregated into clumps.

[0108] Example 13

[0109] A method for using hydroxyethyl cellulose (HEC) and konjac gum as a sludge thickening and coagulant aid. It is mainly applied in sludge thickening tanks in water supply and drainage treatment processes to treat sludge discharge from reaction tanks, sedimentation tanks, and filter backwash wastewater. Hydroxyethyl cellulose (HEC) meets the requirements of GB 2760 01.06 standard, and konjac gum (KGM) meets the requirements of Q / TXDS 0009 S-2022 standard.

[0110] 0.06 g of hydroxyethyl cellulose and 0.05 g of konjac gum were combined and added to 100 mL of ultrapure water to prepare an aqueous solution with an HEC concentration of 0.60 g / L.

[0111] Water source conditions: A water treatment plant in Jinan City, Shandong Province; water source: sludge discharge from the water plant, with a water content of 99.35%. The specific resistance of the sludge without flocculant was measured to be 1.09 × 10⁻⁶. 9 s 2 / g, belonging to the category of sludge that is difficult to mechanically concentrate. The invented product was diluted with the water sample at a concentration ratio of 1:1000 (that is, 1 mL of HEC composite solution with a concentration of 0.60 g / L was added to 1L of raw water sample), and the final HEC dosage was 0.60 mg / L.

[0112] Results: Compared to before adding the coagulant aid, the water sample with added HEC composite KGM showed a decrease in moisture content from 99.35% to 95.46%, and a decrease in sludge specific resistance from 1.09 × 10⁻⁶. 9 s 2 / g decreased to 1.73×10 8 s 2 / g, mud-water separation interface height 200 mm (liquid level 500 mm). The supernatant is relatively clear, and the sludge flocs are aggregated into clumps.

[0113] Comparative Example 1

[0114] Compared with Example 6, the only difference is that the flocculant added is not polyaluminum chloride (PAC), but polyaluminum ferric chloride (PAFC).

[0115] Results: The turbidity of the water sample without HEC compound KGM decreased from 6.60 NTU to 4.78 NTU, and the absorbance at UV254 decreased from 0.078 cm⁻¹. -1 It decreased to 0.067 cm. -1 TOC decreased from 3.58 mg / L to 3.21 mg / L. Smaller flocs formed, and a slower sedimentation rate were observed. The color of the treated water sample changed. The turbidity of the water sample treated with HEC-KGM decreased from 6.60 NTU to 2.05 NTU, and the absorbance at UV254 decreased from 0.078 cm⁻¹. -1 Decreased to 0.041 cm -1 TOC decreased from 3.58 mg / L to 1.89 mg / L. The flocs formed were smaller than those with added PAC, the sedimentation rate was slower, and the color of the treated water sample changed slightly.

[0116] Comparative Example 2

[0117] Compared to Example 6, the only difference is that the flocculant added is not polyaluminum chloride (PAC), but polyferric sulfate (PFS).

[0118] Results: The turbidity of the water sample without HEC compound KGM decreased from 6.60 NTU to 4.80 NTU, and the absorbance at UV254 decreased from 0.078 cm⁻¹. -1 Rising to 0.154 cm -1 TOC decreased from 3.58 mg / L to 3.25 mg / L. Smaller flocs formed, and a slower sedimentation rate were observed. The color of the treated water sample changed. The turbidity of the water sample treated with HEC-KGM decreased from 6.60 NTU to 2.84 NTU, and the absorbance at UV254 decreased from 0.078 cm⁻¹. -1 Rising to 0.121 cm -1 TOC decreased from 3.58 mg / L to 2.59 mg / L. The flocs formed were smaller than those with added PAC, the sedimentation rate was slower, and the color of the treated water sample changed.

[0119] By comparing Example 6 with Comparative Examples 1 and 2, it can be seen that for other types of flocculants, although they can reduce turbidity and remove a certain amount of TOC before adding coagulant aid, the turbidity value and TOC do not decrease significantly after adding coagulant aid. Therefore, in this application, the combination of coagulant aid and flocculant polyaluminum chloride has a better effect and is more conducive to improving the sewage treatment effect.

[0120] Experimental Example 1

[0121] The toxicity of coagulant and polyacrylamide (PAM) was tested using *Bacillus luminifera* and a matching kit that meet national standards. The matching kit included: resuscitation diluent, osmotic pressure adjusting solution, and positive control solution. The tests were performed using a water quality biotoxicity analyzer. The operating procedure followed the instructions for the water quality biotoxicity analyzer. The operating procedure included:

[0122] Reagent preparation: Equilibrate the lyophilized Bacillus luminifera at room temperature for 10 min; hydrate the lyophilized Bacillus luminifera powder reagent with resuscitation diluent; pipette the reagent; let the hydrated reagent stand at room temperature for 15 min.

[0123] Blank preparation: Mix pure water and osmotic pressure regulating solution in a ratio of 9:1; use a pipette to blow the reagent to obtain a blank control sample, i.e., a non-toxic water sample.

[0124] Sample preparation: Mix the sample to be tested with the osmotic pressure regulating solution at a ratio of 9:1; use a pipette to blow the reagent to mix it evenly; place test tubes A1 and A2 in positions A1 and A2 of the test tube rack.

[0125] Reagent and sample reaction: Add 1 mL of osmotically adjusted blank control sample to tube A1 and 1 mL of osmotically adjusted sample to tube A2; add 50 μL of hydrated reagent to tubes A1 and A2 respectively, with an interval of 20 s between additions, and mix by pipetting with a 1 mL pipette; allow the reagent to react for 15 min, starting the timer from the moment the reagent is added to tube A1.

[0126] The A1 and A2 tubes were tested using a water quality biotoxicity analyzer to obtain the blank luminescence value of the A1 tube and the reading of the A2 tube. The instrument automatically provides the relative luminescence and RLU value of the sample.

[0127] The samples in tube A2 above included the coagulant aqueous solution and PAM aqueous solution of this application. The HEC concentration in the coagulant aqueous solution and the PAM concentration in the PAM aqueous solution were the same, and multiple concentration groups were set up. The HEC concentrations in the coagulant aqueous solution were 2 g / L, 3 g / L, 4 g / L, 5 g / L, 6 g / L, 7 g / L, and 8 g / L, respectively, including a mass ratio of hydroxyethyl cellulose to konjac gum of 0.1:0.05. The experiment was conducted under the condition that the reagent reaction time was 30 min, and the results are as follows. Figure 1 As shown, through Figure 1 As can be seen, under different bacterial growth time conditions, PAM has a significantly higher growth inhibition rate than the coagulant in this application.

[0128] Comparative Example 3

[0129] Water source conditions: Lake water in Jinan City, Shandong Province; raw water turbidity: 6.60 NTU; raw water absorbance at UV254 using a UV spectrophotometer: 0.078 cm⁻¹ -1 The TOC of the raw water is 3.58 mg / L.

[0130] Treatment method: Add only PAC, and the amount of PAC added is the same as in Example 6.

[0131] Comparative Example 4

[0132] Water source conditions: Lake water in Jinan City, Shandong Province; raw water turbidity: 6.60 NTU; raw water absorbance at UV254 using a UV spectrophotometer: 0.078 cm⁻¹ -1 The TOC of the raw water is 3.58 mg / L.

[0133] Treatment method: PAC was added after PAM was added. The amount of PAC added was the same as in Example 6, and the amount of PAM added was the same as in Example 6. PAM was added 1 min after the flocculant was added.

[0134] Comparison of turbidity after wastewater treatment in Example 6, Comparative Example 3, and Comparative Example 4 Figure 2 As shown. Examples 6, 3, and 4 show the UV254 comparison after wastewater treatment. Figure 3 As shown, Figure 3 The vertical axis, UV254 value, represents the absorbance value under ultraviolet light at a wavelength of 254 nm. Examples 6, 3, and 4 show the TOC values ​​after wastewater treatment. Figure 4 As shown. Figure 2 , Figure 3 and Figure 4 The PAC+ novel coagulant in this application corresponds to Example 6. Through... Figure 2 , Figure 3 and Figure 4 It can be seen that the coagulant aid of this application, when used in combination with PAC, can improve the wastewater treatment effect compared to PAM.

[0135] Furthermore, although exemplary embodiments have been described herein, their scope includes any and all embodiments based on this application that have equivalent elements, modifications, omissions, combinations (e.g., schemes involving intersections of various embodiments), adaptations, or alterations. Elements in the claims will be interpreted broadly based on the language used in the claims and are not limited to the examples described in this specification or during the implementation of this application, which will be interpreted as non-exclusive. Therefore, this specification and examples are intended to be considered illustrative only, and the true scope and spirit are indicated by the following claims and the full scope of their equivalents.

[0136] The above description is intended to be illustrative and not restrictive. For example, the above examples (or one or more of them) can be used in combination with each other. Other embodiments may be used by those skilled in the art upon reading the above description. Furthermore, in the above detailed description, various features may be grouped together to simplify the application. This should not be construed as an intention that a feature of an unclaimed application is necessary for any claim. Rather, the subject matter of this application may be less than all the features of an embodiment of a particular application. Thus, the following claims are incorporated herein by reference as examples or embodiments, wherein each claim is independently considered as a separate embodiment, and these embodiments are contemplated as being possible in various combinations or arrangements. The scope of the invention should be determined by reference to the appended claims and the full scope of their equivalents.

[0137] The above embodiments are merely exemplary embodiments of this application and are not intended to limit the present invention. The scope of protection of the present invention is defined by the claims. Those skilled in the art can make various modifications or equivalent substitutions to the present invention within the spirit and scope of this application, and such modifications or equivalent substitutions should also be considered to fall within the scope of protection of the present invention.

Claims

1. A method for treating wastewater containing organic carbon, characterized in that, The treatment method includes: adding flocculant to the wastewater while it is being stirred, followed by adding coagulant aid, stirring, and then allowing it to settle. The settled wastewater is then subjected to solid-liquid separation to obtain treated water. The wastewater has a sludge specific resistance of less than 0.5 × 10⁻⁶. 8 s 2 The wastewater contains a concentration of / g, and the TOC in the wastewater is greater than 3 mg / L; the pH of the wastewater is 7.5-9.0; and the temperature of the wastewater is 20-25 ℃. The flocculant is polyaluminum chloride; The coagulant is composed of hydroxyethyl cellulose, konjac gum and water. The coagulant is a transparent liquid. The mass ratio of hydroxyethyl cellulose to konjac gum in the coagulant is (0.01-0.15):0.

05. The concentration of hydroxyethyl cellulose in the coagulant is 0.1-1.5 g / L. The dosage of the coagulant is 0.1-1.5 mg / L relative to the wastewater.

2. The processing method according to claim 1, characterized in that, The wastewater mixing process includes rapid mixing, medium-speed mixing, and slow mixing, with the mixing speed decreasing sequentially. Flocculants are added during rapid mixing, coagulant aids are added during medium-speed mixing, and the mixture is allowed to stand after slow mixing. The mixing process involves 30-60 seconds of rapid mixing, 1-2 minutes of medium-speed mixing, and 10-15 minutes of slow mixing, with the rapid mixing speed being 250-350 r, the medium-speed mixing speed being 100-200 r, and the slow mixing speed being 30-50 r.

3. A method for treating wastewater from a sludge thickening tank, characterized in that, The treatment method includes adding a coagulant aid to the wastewater, stirring, and then allowing it to stand. The wastewater includes sludge discharge water from the reaction tank, sludge discharge water from the sedimentation tank, and / or backwash wastewater from the filter. The coagulant is composed of hydroxyethyl cellulose, konjac gum, and water. The coagulant is a transparent liquid, and the mass ratio of hydroxyethyl cellulose to konjac gum in the coagulant is (0.01-0.15). 0.05, wherein the concentration of hydroxyethyl cellulose in the coagulant is 0.1-1.5 g / L.

4. The processing method according to claim 3, characterized in that, The wastewater has a pH of 7.5-10.0 and a temperature of 20-25 °C.

5. The processing method according to claim 4, characterized in that, The dosage of the coagulant is 0.1-0.8 mg / L relative to the wastewater.

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