Study On Gentamicin Production Wastewater Process Design And Operation Technology

Gentamicin wastewater with complicated composition and high concentration organic pollutant is difficult to be treated. In this study, the treatment process of gentamicin production wastewater was designed and the operation control of main treatment units were investigated1) The treatment process of “UASB + anoxic/aerobic(A/O)” was used to treat gentamycin wastewater. The desighed volumetric loading rate of UASB was 10.0kgCOD/ m3·d and its HRT was 24 h. The total volume of A/O tank was 7425 m3, and the volume ratio of aerobic tank to anoxic tank was 2. The backflow ratio of mixed liquor was 150% and the backflow ratio of sludge was 50%. The treated effluent quality would meet the requirements of both discharge limition of Table 2 in “discharge standards of water pollutants for pharmaceutical industry fermentation products category”(GB21903-2008) and influent quality of local wastewater treatment plant.2) The batch influent was applied for UASB start up. The influent COD concentration was controlled as 4500~5100 mg·L-1, and the loading rate for start up was 1.0 kgCOD·(m3·d)-1. The influent loading rate reached to 4.0kgCOD·(m3·d)-1 after 45 d running. Then influent loading rate increased from 4.3kg COD/(m3·d) to 9.84kgCOD·(m3·d)-1 after 50 d running. The stable operation performance of UASB were average loading rate of 9.95 kg COD/(m3·d), average effluent COD concentration of 778 mg/L and average COD removal rate of 92.3%, when the treatment capacity was 970~1040m3/d and influent COD concentration was 9780~10860mg/L. The granular sludge appared in the UASB when the sludge loading rate reached to 0.23 kgCOD·(kgVSS·d)-1. The rapid sludge granulation was promoted when the sludge loading rate reached to 0.41 kgCOD·(kgVSS·d)-1. In addition, the sludge granulation could also be enhanced when hydraulic loading rate increased to higher than 0.40 m3·(m2·h)-1.3) The operation performance of A/O indicated that the average effluent COD and ammonia concentrations were 73.1 mg·L-1 and 23.8mg·L-1, the corresponding removal rates were 90.3% and 91.5%, when the operation conditions were controlled as: influent COD concentration of 800~1020 mg·L-1, influent ammonia concentration of 241~249 mg·L-1, DO concentration of 3~4 mg·L-1 and backflow ratio of nitrated liquor of 2.4) When the treatment process of “UASB + anoxic/aerobic(A/O)” was used to treat gentamycin wastewater, the treated effluent could meet the designed requirements. The COD of 9810.9 t?a-1 and nitrogen of 178.2 t?a-1 could be reduced. Then the environmental benefit was significant.5) The total investment of wastewater treatment project was 13.345 million yuan. wastewater treatment cost was 4.17 yuan/m3 which belongs to medium level.