Coal cinder filtration as pretreatment with biological processes to treat pharmaceutical wastewater

This study aims at coupling coal cinder filter with biological process to improve pharmaceutical wastewater quality and reduce the disposal cost. In the coal cinder filter, the removal efficiencies of COD, BOD₅, SS and color were 90 ± 2%, 72 ± 2%, 95 ± 2% and 80 ± 2%, respectively. The results attribute to the big specific surface area and strong adsorption ability. Coal cinder filter removes a large portion of the pollutants in the influent wastewater, which would strongly stable the effluent waste water quality, and reduce the load of follow-up biological treatment process. The average removal efficiencies for COD, BOD₅, SS and color of the combined process were about 99.7 ± 3%, 98.2 ± 4%, 98.5 ± 3% and 96.3 ± 2%, respectively, with the average effluent quality of COD 16 ± 1 mg/L, BOD₅ 11 ± 1 mg/L, SS 10 ± 0.6 mg/L and color 22 ± 1 (multiple), which are consistent with the national requirements of the waste pollutants for pharmaceutical industry of chinese traditional medicine discharge standard (GB 21906-2008). The results indicated that the combined procedure could offer an attractive solution for pharmaceutical wastewater treatment with considerable low cost.