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CN-117800513-B - Method for treating bamboo retting pulp waste liquid

CN117800513BCN 117800513 BCN117800513 BCN 117800513BCN-117800513-B

Abstract

The invention discloses a method for treating bamboo retting pulp waste liquid. The method comprises the steps of enabling bamboo chip retting waste liquid to enter a homogenizing adjusting tank through a collecting tank, carrying out nano aeration to carry out homogenizing mixing and oxidization, carrying out flocculation precipitation on the waste liquid subjected to nano aeration twice, enabling supernatant fluid after flocculation precipitation to enter a self-electrolysis treatment tank for self-electrolysis for 1-2 hours, enabling waste liquid after self-electrolysis treatment to enter a salt-resistant biochemical treatment system, enabling effluent of the salt-resistant biochemical treatment system to enter an A/O biochemical system for treatment, enabling effluent of the A/O biochemical system to enter a final sedimentation tank, enabling the waste liquid to be subjected to solid-liquid separation through inclined tube precipitation, enabling the effluent to flow into a discharge tank after the effluent, and enabling a nano tube to enter a comprehensive sewage treatment system. The process is suitable for treating high-concentration industrial wastewater, particularly industrial wastewater with the wastewater concentration COD of more than or equal to 40000mg/L, provides a practical and feasible process for treating the high-concentration retting pulp waste liquid of the small scattered bamboo chips, and provides a scheme for solving the environmental pollution.

Inventors

  • LI GUANGSHENG

Assignees

  • 华南理工大学

Dates

Publication Date
20260508
Application Date
20231121

Claims (6)

  1. 1. The method for treating the bamboo retting pulp waste liquid is characterized by comprising the following steps of: (1) The bamboo chip retting pulp waste liquid enters a homogenizing regulating tank through a collecting tank, and is subjected to homogenizing mixing and oxidization by adding nano aeration in the homogenizing regulating tank, wherein the COD (chemical oxygen demand) of the bamboo chip retting pulp waste liquid is more than or equal to 40000 mg/L, the TDS is more than or equal to 10000 mg/L, and the pH value is 10-13; (2) The waste liquid after nano aeration enters a primary flocculation sedimentation tank and is added with a flocculating agent for sedimentation, filter-pressed effluent after the primary flocculation sedimentation enters a secondary flocculation sedimentation tank and is added with a flocculating agent, wherein the particle size of bubbles of nano aeration is 70-100 nm, and the density is 3-4 millions/mL, the flocculating agent consists of aluminum oxide and mineral adsorbents, the content of the aluminum oxide is above 26 percent, and the mineral adsorbents comprise zeolite and kaolin; (3) The supernatant fluid after flocculation and precipitation in the secondary sedimentation tank automatically flows into a self-electrolysis treatment tank, the pH value of the wastewater is regulated to 8-9, pure iron is taken as an anode, iron carbide is taken as a cathode, and the self-electrolysis time is 1-2 h; (4) The waste liquid after the self-electrolysis treatment tank enters a salt-tolerant biochemical treatment system, wherein the salt-tolerant biochemical treatment system contains compound photosynthetic bacteria and EM bacteria, the mass ratio of the compound photosynthetic bacteria to the EM bacteria is 7:3-8:2, and the compound photosynthetic bacteria is BioPower 600 salt-tolerant bacteria; the composite photosynthetic bacteria and EM bacteria are firstly domesticated and cultured before waste liquid is treated, and the method comprises the steps of taking water discharged from an electrolytic treatment tank as a water source, performing 7 days of domestication by sequencing batch step water inflow of 10%, 20%, 30%, 40%, 50%, 70% and 100%, or performing continuous 10 days of domestication by 10% water inflow under an anoxic environment; (5) The effluent of the salt-resistant biochemical treatment system automatically flows into an A/O biochemical system for treatment, wherein in the treatment of the A/O biochemical system, the content of dissolved oxygen is 4 mg/L-6 mg/L, the hydraulic retention time is that the section A is less than or equal to 24h, the section O is less than or equal to 16h, the temperature is 10 ℃ to 40 ℃, and the COD of the effluent treated by the A/O biochemical system is less than or equal to 1000mg/L; (6) The effluent of the A/O biochemical system enters a final sedimentation tank, solid-liquid separation is carried out on waste liquid through inclined tube sedimentation, then the effluent flows into a discharge tank, and the nano tube enters a comprehensive sewage treatment system.
  2. 2. The method of claim 1, wherein the hydraulic retention time of the waste liquid in the homogenization adjustment tank is 0.5-2 hours.
  3. 3. The method of claim 1, wherein the primary flocculation sedimentation tank and the secondary flocculation sedimentation tank are vertical sedimentation tanks, flocculation sedimentation time is 2-10 hours, and the addition amount of flocculant in the primary flocculation sedimentation tank and the secondary flocculation sedimentation tank is 0.1-0.2 mg/L.
  4. 4. The method of claim 1, wherein the salt tolerant biochemical system is selected from one of a biofilm reactor, an SBR reactor, a batch aerated biological filter reactor, and a UASB anaerobic reactor.
  5. 5. The method of claim 1, wherein the composite photosynthetic bacteria are BioPower 600,600 salt tolerant bacteria, and the hydraulic retention time of the waste liquid in the salt tolerant biochemical treatment system is 144-192 hours.
  6. 6. The method according to claim 1, wherein the composite photosynthetic bacteria and EM bacteria are added in an amount of 0.005-0.01% by mass of the waste liquid after passing through the self-electrolysis treatment tank.

Description

Method for treating bamboo retting pulp waste liquid Technical Field The invention belongs to the technical field of environmental pollution treatment, and particularly relates to a method for treating bamboo retting pulp waste liquid. Background The bamboo pulp can be used for replacing part of pulp, and can be added into packaging paper and the like to replace part of waste pulp. The main steps of bamboo pulping include cutting bamboo into bamboo chips in certain length, soaking in alkali solution, cutting into fine bamboo filaments, and mechanical grinding. The waste liquid of the bamboo retting pulp is black and has stimulated taste, the content of soluble solids is high, TDS is more than or equal to 10000mg/L, the content of organic pollutants is high, impurities such as lignin and pectin are contained, the waste liquid contains high-concentration COD Cr (40000 mg/L-80000 mg/L), the waste liquid is slightly alkaline (pH is 10-13), and the suspended particles are more, so the waste liquid belongs to a high-concentration industrial waste liquid which is difficult to treat. If the bamboo retting waste liquid is not properly treated, the environment can be polluted, and the surrounding ecology can be damaged. Chinese patent application CN 110713320A discloses a system and method for advanced treatment of papermaking wastewater, in which the COD of the papermaking wastewater inlet water treated by the method is less than 200mg/L, the method is an advanced treatment process for effluent of a secondary sedimentation tank for papermaking wastewater treatment, and the process is only suitable for low-concentration papermaking wastewater treatment. The waste liquid of retting bamboo chips contains high concentration COD Cr (40000 mg/L-80000 mg/L), so that it is necessary to provide a treatment process suitable for high concentration COD wastewater. Disclosure of Invention In order to solve the defects and shortcomings of the prior art, the invention aims to provide a method for treating bamboo retting pulp waste liquid, which realizes effective treatment of high-salinity and high-concentration bamboo chip retting pulp waste liquid. The invention aims at realizing the following technical scheme: A method for treating bamboo retting pulp waste liquid comprises the following steps: (1) The bamboo chip retting waste liquid enters a homogenizing adjusting tank through a collecting tank, and the homogenizing adjusting tank is added with nano aeration to perform homogenizing mixing and oxidation; (2) The waste liquid after nano aeration enters a first-stage flocculation sedimentation tank and is added with flocculating agent for sedimentation, and filter-pressed effluent enters a second-stage flocculation sedimentation tank and is added with flocculating agent after the first-stage flocculation sedimentation; (3) The supernatant fluid after flocculation and precipitation in the secondary sedimentation tank automatically flows into a self-electrolysis treatment tank, the pH value of the wastewater is regulated to 8-9, and the self-electrolysis time is 1-2 h; (4) The waste liquid after passing through the self-electrolysis treatment tank enters a salt-tolerant biochemical treatment system, wherein the salt-tolerant biochemical treatment system contains composite photosynthetic bacteria and EM bacteria; (5) The effluent of the salt-tolerant biochemical treatment system automatically flows into an A/O biochemical system for treatment; (6) The effluent of the A/O biochemical system enters a final sedimentation tank, solid-liquid separation is carried out on the waste liquid through inclined tube sedimentation, then the effluent flows into a discharge tank, and the nano tube enters a comprehensive sewage treatment system. Preferably, the COD of the bamboo chip retting pulp waste liquid is more than or equal to 40000mg/L. Preferably, the particle size of the nano-aeration bubbles is 70 nm-100 nm, the density is 3-4 millions/mL, and the hydraulic retention time of the waste liquid in the homogenizing regulating tank is 0.5-2 hours. Preferably, the primary flocculation sedimentation tank and the secondary flocculation sedimentation tank both adopt vertical flow sedimentation tanks, and the flocculation sedimentation time is 2-10 hours. Preferably, the addition amount of the flocculating agent in the primary flocculation sedimentation tank and the secondary flocculation sedimentation tank is 0.1-0.2 mg/L. Preferably, the flocculant is PAC. More preferably, the flocculant consists of alumina and a mineral adsorbent, the alumina content being above 26%, the mineral adsorbent comprising zeolite and kaolin. Preferably, the self-electrolysis treatment cell takes pure iron as an anode and iron carbide as a cathode. Preferably, the salt-tolerant biochemical system can be one of a biomembrane reactor, an SBR reactor, an intermittent aeration biological filter reactor and a UASB anaerobic reactor, and is most preferably an intermittent a