Treatment Of Cotton Pulp Wastewater By Up-Flow Multi-Stage Anaerobic Reactor

The operating principle and the structure of up-flow multi-stage anaerobic reactor (UMAR) is detailed introduced in this paper. According to the properties of the wastewater of cotton pulp, the pilot-stage UMAR reactor is designed and is made up by ourselves.The analysis of the wastewater of cotton pulp indicates that the cotton pulp wastewater is feasible treating by anaerobic treatment, as the COD concentration of cotton wastewater is 10000 mg/L, the BOD/COD of the cotton wastewater is around 0.33. In order to gaining a higher COD removal rate, the optimum technological conditions was showed that the concentration of sludge in reactor is 28g/L, and the concentration of inlet wastewater is controlled as 8500mg/L, pH7.5.The pilot-stage study of cotton pulp wastewater is carried out in Hebei Jigao chemical fibre factor by UMAR. After the start-up time of the reactor, as 50 days, it accomplishes the start-up objective: the COD removal rate 54%, the volumetric loading 6KgCOD/(m~3·d), the rate of gases 0.31 m~3/KgCOD. When the system operation is steadily, the safety volumetric loading can be 16 to 20KgCOD/(m~3·d) by increasing the volumetric loading gradually, and the COD removal rate is above 55%, the rate of gases is about 0.29m~3/KgCOD. The cotton pulp wastewater with Fe-C pre-treating has a better effect of anaerobic treatment. Using pre-treating wastewater, the COD removal rate increases obviously, as 65～70%, and the rate of gases is 0.32m~3 /KgCOD.The degradation mechanics of the COD is tried to study by FTIR technology. By the determination and analysis of FTIR, the process of cotton pulp wastewater can be described that organics with large molecular is degraded to fat acid which with small molecular.