Ramie Degumming Wastewater Treatment

The current situation and new progresses of treatment methods for wastewater were reviewed from home and abroad. The applications of new methods and techniques were summarized, such as photocatalytic oxidation, fraction alanaerobic, hydrolytic acidification, sequencing batch reactor, and biochemical- photocatalytic oxidation. With the development of new methods and techniques, wastewater will be treated more efficiently. It is well known that ramie-degumming wastewater has high COD_Cr concentration,high color and some toxicants to microorganics. Based on the distinctive characteristic of ramie degumming wastewater we put great emphasis on the treatment of ramie-degumming wastewater from experimental angle.After comparing and analysing from treatment effect and technology availability as well as cost, we decided to adopt the process of acidification-internal electrolysis coagulation -anaerobic aerobic treatment and studied the treatment effect and affecting factor of this process when it was employed to treat the ramie-degumming wastewater.Meanwhile we made success in acclimating the biological membrane that can degrade ramie-degumming wastewater effectively through the proper method. After finishing experiments,we draw several conclusions as follows:â‘ The result of acidification is:in 55℃, 10% vitriol was used to decrease pH to 3,the exenterate of COD_Cr is about 35%,SS is 75%,chromaticity is 96%.â‘¡In the process of internal electrolysis coagulation we can improve the degradability and reduce CODcr and chromaticity.The result of internal electrolysis coagulation is:in normal temperature,the pH is 3,the retention time is 180min,mass ratio of Fe&C to wastewater=0.2, Fe:C=5, the exenterate of COD_Cr is about 20%,chromaticity is 25%. BOD₅/COD_Cr is improved from 0.18 to 0.34,it is favorable for the next biological treanment.â‘¢Mixed the other ramie degumming wastewater with the wastewater of pretreatment,it would enter anaerobic treatment reactor.In 35℃,the entrance COD_Cr is less than 4800mg/L, the retention time is three days,Nv is 7.5kgCOD/m³Â·d,the exenterate of COD_Cr is 55%, chromaticity is 30%.The step could not only reduce pollutants but also produce nature gas.â‘£After anaerobic treatment, the outfall wastewater enter into aerobic reactor.Aerobic treatment ran well, Nv is 1.5kgCOD/m³Â·d (the retention time is about 24h), the exenterate of COD_Cr is between 25% and 30%,chromaticity is less than 20%.⑤The process of acidification-internal electrolysis coagulation-anaerobic aerobic treatment ran well in the ramie degumming wastewater experiment,the exenterate of COD_Cr is more than 97%,chromaticity is more than 98%.It proved the process is available.