At present, the typical wastewater COD exceeds the standard mainly includes electroplating, circuit board, papermaking, pharmaceutical, textile, printing and dyeing, chemical and other wastewater, so what are the treatment methods for COD wastewater? Let’s go and see together.
Wastewater COD classification.
The sources of production wastewater are divided into: industrial wastewater, agricultural wastewater, and medical wastewater.
Domestic sewage refers to a complex mixture of various forms of organic matter composed of inorganic and organic matter, including:
① Floating or suspended large and small solid particles
②Colloidal and gel-like diffusers
③Pure solution.
The treatment methods of COD wastewater include:
Removal of COD by coagulation method: chemical coagulation method can effectively remove organic matter in wastewater and reduce COD to a large extent. Coagulation process is adopted, by adding flocculant, using the adsorption and bridging of flocculant, the electric double layer is compressed, so that the colloid and suspended matter in the water are destabilized, collided, and condensed into flocs, and then the sedimentation or air flotation process is used to remove the Particles are separated from the water, so as to achieve the purpose of purifying the water body.
Biological method to remove COD: Biological method is a wastewater treatment method that relies on microbial enzymes to oxidize or reduce organic matter to destroy unsaturated bonds and chromophores to achieve the purpose of treatment. In recent years, microorganisms have been widely used in the treatment of scouring wastewater due to their fast reproduction speed, strong adaptability and low cost.
Electrochemical COD removal: The essence of electrochemical wastewater treatment is to use electrolysis directly or indirectly to remove pollutants in water, or to convert toxic substances into non-toxic and low-toxic substances.
Removal of COD by micro-electrolysis: Micro-electrolysis technology is currently an ideal method for treating high-concentration organic wastewater, also known as internal electrolysis. The invention uses micro-electrolysis materials to fill waste water under the condition of no electricity, and generates 1.2V potential difference by itself to electrolyze waste water to achieve the purpose of degrading organic pollutants.
COD removal by absorption method: activated carbon, macroporous resin, bentonite and other active adsorption materials can be used to adsorb and treat particulate organic matter and chroma in sewage. It can be used as pre-treatment to reduce COD which is easier to handle.
Oxidation method to remove COD: In recent years, the application of photocatalytic oxidation technology in the field of wastewater treatment has good market prospects and economic benefits, but there are still many problems in the research in this field, such as finding high-efficiency catalysts, separation and recovery of catalysts wait.
Post time: Apr-17-2023
