Experimental study on bathing wastewater pretreatment by coagulation sedimentation process

Using coagulation sedimentation process to pretreat bathing wastewater,the effects of coagulation stirring intensity,coagulant dosage,pH value of the wastewater,sedimentation time and some other factors on CODCr and turbidity removal were investigated;meanwhile,the optimal operation condition of the coagulation sedimentation process was also studied.The results of the test showed that,the optimal operation condition of the said process was: medium speed mixing(100 r/min) 2 min,slow mixing(30 r/min) 5 min,the sedimentation time was 15 min,the dosage of PAC and PAM were 40,2.5-3.5 mg/L respectively,the pH value was 6-9.Under the above condition,the removal rates of CODCr and turbidity of the wastewater reached 76% and 81% respectively.It could be seen that,using coagulation sedimentation process to pretreat bathing wastewater could greatly reduce the load of the following processing unit and provided a guarantee for bathing wastewater reuse.