Project Profile: Jinhua Textile Co., Ltd. is a private enterprise that integrates production, processing, distribution and wholesale of cotton gauze, canvas, polyester cotton, printed cloth, bronzing cloth, bleached polyester cotton, camouflage cloth and so on. The wastewater of the company is mainly the bleaching and dyeing wastewater generated in the production process. The pH value of the wastewater is high and contains a large amount of organic matter, SS and chromaticity. The leaders of the company attach importance to environmental protection. In order to implement the national environmental protection policy and the requirements of local environmental protection departments, the company has formulated environmental protection plans and built a new 2000 tons/day sewage treatment project. Entrusted by it, our company (Ningbo Jingyuan Membrane Technology Co., Ltd.) conducted on-site inspection and water quality analysis of the sewage treatment project, combined with our company's experience in the treatment of textile printing and dyeing wastewater, designed the project.

After the wastewater is treated, it achieves the first-class emission standard superior to the “Dyeing and Finishing Industry Water Pollutant Emission Standard” (GB4287-1992). The specific indicators of the standard are as follows:

Introduction to the project process:

Project process description:

The bleaching and dyeing wastewater from the workshop, the ground mopping wastewater and the domestic sewage in the living area are collected into the grid well through the plant collection system to remove some solid particles, fine woven ribbons and hairs with larger diameters. The wastewater passing through the grid well system enters the pre-exposure adjustment tank to carry out uniform water quality and water quantity, and then is lifted into the coagulation sedimentation tank by the lift pump. Due to the high alkalinity of the wastewater, the darker coagulation sedimentation tank is added by adding FeSO4 and PAM. After the coagulation reaction reduces the alkalinity and unreacted dye particles and some fine solid particles, it also acts as a pretreatment system to reduce the subsequent biochemical load and supplement some iron salts for subsequent biochemistry. The pretreated effluent flows into the hydrolysis acidification tank. The main function of the hydrolysis acidification tank is to degrade the macromolecular organic matter in the wastewater into small molecular substances, and the difficult biodegradable substances are converted into biodegradable substances. Meanwhile, the hydrolysis acidification tank has Good resistance to organic loads and toxic impacts; degradation of solid organics can reduce sludge volume. The water passing through the hydrolysis acidification tank flows into the aerobic pool, and is metabolized by aerobic bacteria perfushed on the filler in the aerobic pool, and is subjected to aerobic treatment to oxidize and decompose the pollutants in the water into CO2 and H2O, thereby completing a large amount of organic matter. After removal, a part of the biological contact oxidation tank effluent is returned to the water inlet of the hydrolysis acidification tank, and at the same time, another part is subjected to the dosing reaction to further remove SS and part of the organic matter, and the treated water flows into the secondary sedimentation tank to separate the mud water. The secondary sedimentation tank is also equipped with PAC, PAM and sodium hypochlorite dosing system to ensure that the sewage treatment station can still meet the standard discharge when it is impacted by water quality and water volume. The water separated by the muddy water of the secondary sedimentation tank flows into the sand filtration system to remove the SS which is not separated from the secondary sedimentation tank. Finally, the water enters the clear water pool, and the water in the clear water pool also serves as the backwash water of the sand filter. The backwashed water is returned to the conditioning tank for reprocessing.

The sludge discharged from the biochemical pool and the inclined tube sedimentation tank is collected into a sludge concentration tank and subjected to centralized dehydration treatment by a plate and frame filter press. The dewatered sludge and the solid waste in the plant area are transported to the landfill for landfill disposal through special solid waste transportation vehicles.

Project Engineering Picture: Factory sewage station