Printing and dyeing wastewater treatment project of a knitting printing and dyeing factory in Changzhou

Project Overview:

This project serves a printing and dyeing factory in Changzhou that specializes in the production of knitted products, and efficiently treats the printing and dyeing wastewater discharged from its workshop. These wastewater have the characteristics of high COD (Chemical Oxygen Demand), high chromaticity, high suspended solids content, high salinity and hardness, which pose significant pressure on the environment. The project aims to achieve the dyeing reuse water quality standards specified in the “Technical Specifications for Textile Dyeing and Finishing Industry Wastewater Treatment Engineering (HJ471-2009)” through professional treatment of wastewater. To this end, a reclaimed water treatment plant with a processing capacity of 3500 cubic meters per day was invested and constructed in 2013.

Processing technology:

The project adopts an advanced treatment process of “hydrolysis acidification+biological contact oxidation+coagulation air flotation+filter+ultrafiltration membrane+reverse osmosis”. Among them, the coagulation air flotation process is one of the key steps. It uses high-quality polyaluminum chloride (PAC) and polyacrylamide (PAM) produced by YuXinHuan as coagulants and coagulants, effectively removing suspended solids, colloids, and some dissolved organic matter in wastewater, laying a good foundation for subsequent ultrafiltration and reverse osmosis treatment.

Application of Yuxinhuan products:

Polyaluminum chloride (PAC): Polyaluminum chloride, professionally produced by YuXinHuan, is an efficient inorganic coagulant. With its strong bridging, net capture, and electrical neutralization capabilities, it can quickly coagulate small particles and colloids in wastewater, forming easily separable flocs, significantly reducing the turbidity and suspended solids content of wastewater.

Polyacrylamide (PAM): As a coagulant aid provided by YuXinHuan, PAM enhances the coagulation effect of PAC through the adsorption bridging effect of its polymer chains, promotes the rapid formation and sedimentation of flocs, and improves the efficiency of wastewater treatment and effluent quality.

Engineering operation effect:

The design capacity of the pre-treatment and reuse system for printing and dyeing wastewater is 3500 cubic meters per day, with a total investment of 6.8 million yuan and a land area of 1300 square meters. The total electrical capacity of the system is 255 kilowatts, and the processing cost is approximately 3.73 yuan/cubic meter. After treatment, the wastewater quality has significantly improved:

The actual operation results show that the treated water quality fully meets the reuse water standards, realizing the resource utilization of wastewater, reducing production costs and environmental burden, reflecting the concept of green production and sustainable development.

Author: YuXinHuan®

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