Technical Study On Biotreatment Of Cyclohexanone Processing Wastewater

Cyclohexanone processing wastewater is a new type effluent of chemical industry which appeared in recent years. This wastewater contains hard biodegradative compounds, so it results in huge environmental contamination, and there is few reports about the treatment technology of the sewage both home and abroad. A systematic study was conducted on the anaerobic biotreatment characteristics of Cyclohexanone processing wastewater. The thesis researched on the starting and running of homemade UBF reactor that adopted cyclohexanone processing wastewater (it included cyclohexanone, cyclohexanol, cyclohexane and so on while the CODCr was 10000~40000mg/L, pH was 1~4,besides these compounds, the wastewater still contained organic acids, Na2SO4, oil and a little of benzene.) which was pretreated by flocculation-Fe/C micro electrolysis-pH adjusting as influent. The thesis arrived some conclusions as follows combining the study and the pilot scale project.①Starting experiment: When VLR was 0.415~0.462kg·COD/(m~3·d), the COD removing efficiency of UBF was about 80%; When VLR was 0.887～0.911kg·COD/(m~3·d), the COD removing efficiency of UBF was about 70%; When VLR was 1.249～1.299kg·COD/(m~3·d), the COD removing efficiency of UBF was about 60%. The toxic organics'inhibition to anaerobe was aggravated and the removing efficiency was decreased gradually as increasing of VLR, but the trend led to flat.②Running experiment: 1) The VLR COD removing efficiency increased as increasing of VLR and its trend led to flat that indicated the resisting shock load ability of UBF was well. 2) The VFA of effluent was high, this phenomenon maybe result from the toxic organics'inhibition to anaerobe, furthermore, the wastewater lacked of inorganic nutritive elements such as Ni, Co, Zn and so forth. 3) The alkalinity of effluent changed hardly, its range maintained among 1200～1500mg/L( CaO ), the maximal alkalinity was 1573mg/L, the minimal alkalinity was 1123mg/L, and the average alkalinity was 1354mg/L. 4) VFA/TA was 0.653～1.233, a little higher. The COD removing efficiency was low, the VFA/TA was high. The COD removing efficiency was high, the VFA/TA was low. 5) When the HRT was 3.07～4.63d, the average COD removing efficiency was 58.82～63.00%, these data indicated that the reactor's removing effect would be poor if the HRT were short. 6) The variety of HRT had a little influence on VFA of effluent, however, when VFA/TA was among 0.66～1.15 and to increase hydraulic loading, the VFA/TA augmented evidently. 7) After acclimation, the settleability of anaerobic sludge and the sludge could form granule.③The optimal controls parameters were gained by study. The optimal parameters: When VLR was 2.36～3.26kgCOD/m~3·d, the COD removing efficiency was 61.74～65.86%.④The pilot scale project disposed the sewage successfully depending on the studying results and practice. After 4 months'debugging, the water quality accord with the technical norms.