Zero Emission for Dyeing/Printing Plant     

A wastewater treatment project by Weifang Jinsida Printing and Dyeing Co., Ltd. has drawn attention from the dyeing industry in China as well as the environmental protection sector recently.
   In the company's treatment project wastewater is used to produce biogas which will be used to generate power for the reuse of wastewater treatment. This process realizes the recycling use of reclaimed water. The wastewater in dyeing production, with anaerobic treatment, is used to produce biogas, which will produce power to feed the project in return. The precipitated sludge, after being dehydrated and dried, is mixed with coal for boiler combustion, so as to achieve zero emission.
   Weifang Jinsida's chairman Liu Guotian said the waste treatment in dyeing and printing production project, which encompasses improved anaerobic treatment technology, wastewater decolorization technology, and boiler ash-based wastewater filtration technology, could help the company save 4.86 million cubic meters of water per year, 3.24 million kilowatt hours of power per year, or RMB8.48 million worth of fuel power costs. This brings better environmental, economic and social benefits.
   The combination of these technologies, with broad applicability could be also used in a range of industries including textile, paper and food processing as long as the sewage contains organic substances, which can be used to produce methane while other hazardous substances could be removed by upgrading equipment, according to Liu.
   The company is based in Changyi, Shandong province. Dubbed China's renowned dyeing and printing city, Changyi is home to 41 dyeing and printing companies. The city could save an estimated RMB300 million from wastewater treatment by using the technologies in wastewater treatment.