| A Bio-engineering Co., Ltd. is establishing a technological upgrading project, which produces 500 tons Nisin and 100 tons Natamycin every year. Company’s existing wastewater treatment system has lost original design processing capacity because of having been neglected for years, which can’t satisfy the technological upgrading project needing more processing capacity. Thus, the company has bulit a new wastewater treatment system which is suitable for technological upgrading project. The new system uses combined physico-chemical pretreatment process of Fe-C micro-electrolysis and Fenton. The biochemical treatment process is combination of UASB, PACT and inverted AAO.This system completed the civil construction, equipment installation and begined to adjust in November 2014.This thesis topic is mainly about the pretreatment of antibiotic wastewater with Fe-C micro-electrolysis- Fenton process. Meanwhile, the biochemical combination treatment process of UASB, PACT and inverted AAO is studied. Through lab-scale test and full-scale test, the changes of water quality indicators and problems existing are researched and analysised, and the results provide a good reference for practical wastewater treatment engineering operation.Treatment of antibiotic wastewater by structured Fe-C micro-electrolysis packing was studied. The results show that the optimal COD removal rate(27.2%) is achieved when the influent p H, solid-liquid ratio and reaction time is 3.0, 480 g/L and 120 min respectively. Meanwhile, the results of kinetic analysis indicate that the Fe-C micro-electrolysis degradation process of COD could be described by third-order reaction kinetics. The kinetic equation is established.Treatment of antibiotic wastewater by the combination process of Fe-C micro-electrolysis and Fenton was studied. The results show that the optimum reaction conditions are initial dosage of H2O2, 500 mg/L; adjustment p H of Fenton oxidation pond water, the rage of 8.0 to 9.0 and dosage of PAM, 2.5 mg/L. When the p H of wastewater is in the range of 2.5~3.0, the effective dosage of H2O2 300 mg/L, adjustment p H to 9.0, the dosage of PAM about 2 mg/L. The removal rate of COD can reach up to 40.1% on the average, total phosphorus removal rate can reach more than 80%, and B/C is incresead from 0.15 to 0.35. The type of small molecule organic compounds of effluent is significantly more than influent. Thus biodegradability of wastewater is improved.UASB reactor experienced four stages of sludge acclimatization period, load increasing period, restart period and high load operation period, lasted 138 days. When the flow is design value, the volume load of 2.31 kg COD/(m3·d), the average removal rate of COD is 70%.The volume load of PACT pool is in the design value of 2.00 kg COD/(m3·d), COD removal rate can remain above 70%, ammonia nitrogen removal rate is more than 95%. The system was running in the condition of malnutrition, low temperature, and low load, activated sludge bulking appeared. However, this didn’t affect the effect of wastewater treatment. Activated sludge bulking phenomenon disappeared after about 49 days through discharge of sludge to improve sludge load.Under the design flow, COD removal rate can remain above 93%, ammonia nitrogen removal rate can reach up to 98%. The water quality indicators of biochemical system effluent can meet wasterwater discharge standard in addition to the effluent TP. Effluent COD can be under 500 mg/L, ammonia nitrogen concentration lower than 5 mg/L, p H around 9.0. |
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