Pilot-Scale Experiment Of Wastewater Of Viscose Fiber With Cass-phsical-chemical Technology

The viscose fiber which taken cotton and wood pulp as raw material plays animportant role in chemical cellulose. While during its production, wastewater with high concentration is produced due to consuming a lot of chemical raw material and it will cause environment hazards if it is not properly treated. Nowadays the wastewater can't accord with the discharging standard by the current treated process. A study was carried out to assess the efficiencies of Cyclic Activated Sludge System (CASS) to treat wastewater of viscose fiber and find out proper coagulant. The main object was to assess the effect on a pilot scale reactor, while studying the behavior of the system at different operation condition and search a suited coagulant that can effetely treat the wastewater. The results show, after 65 days, the CODcr and BOD5 removal efficiency can be respectively improved to 77.12% and 86.94% when the activated sludge loading is 0.05 kgCODcr/ kgMLSS·d. And this proves the activated sludge has been adapted to the wastewater of viscose fiber. From the 71th day, it enters the normal operation period and the operational cycle time is adjusted to eight hours from original twelve hours, then from the 91th day, the operational cycle time is adjusted to six hours from original eight hours. The pilot shows CODcr removal efficiency is stabilized within 75%~80% that proves the CASS system has sound capability to resist shock load. The laboratory experiment shows the CODcr of effluent water can accord with one level of discharging standard by adding PAC(470～900mg/L) and PAM (2mg/L). From the pilot experiment, we can get a conclusion that the CODcr and BOD5 removal efficiency can be respectively improved to 85% and 79%. And all the targets of effluent water meet the design requirement. Through this experiment research, the operational parameters and technology foundations can be offered for project design and running. In the real project, the factors should be modified according to the reality to get the best results.