高级氧化工艺与生物移动床耦合处理农药废水研究

Treatment of pesticide wastewater by moving-bed bioreactor combined with advanced oxidation technology

通过实验比较了UV/TiO2/H2O2、Fenton试剂和UV/TiO23种高级氧化工艺对农药废水的预处理效能,表明Fenton试剂最为经济高效.优化得出Fenton试剂的最佳工艺条件是H2O2投加量为97mmol/L,Fe2+浓度为40 mmol/L.该条件下可将农药废水的COD从33 700 mg/L降至12 000 mg/L以下,其可生化性由0.2升至0.45以上.预处理后的废水经好氧生物移动床处理COD去除率可以达到85%以上;当载体表观体积降至15%时,COD去除率仍能达到80%以上,载体体积为10%时去除率只有70%左右,15%的表观体积是该载体在生物移动床中的极限体积;此时载体上的生物量超过6 000 mg/L,也说明该载体适合微生物生长且移动床工艺具有很强的抗冲击负荷能力.

Three kinds of advanced oxidation processes used to pretreat pesticide wastewater. The experimental including UV/TiO2/H2O2, Fenton and UV/TiO2 were results showed that the Fenton process was the most effective and economical method to pretreat the pesticide wastewater by comparing COD removal efficiency and operation cost. The optimal experimental conditions of the Fenton process were an Fe^2＋ concentration of 40 mmol/L and an H2O2 dose of 97 mmol/L. COD could be sharply decreased from 33 700 mg/L to below 12000mg/L under the optimal condition, and the biodegradability of the wastewater was enhanced from 0.2 to above 0. 45. The pretreated wastewater then was further treated by an aerobic moving-bed bioreactor; the final stable COD removal efficiency achieved was up to 85%. The stable COD removal efficiencies can still reached beyond 80% even though the bio-carries apparent volume was decreased to 15%. While the bio-carries apparent volume was as low as 10%, the stable COD removal efficiency was only about 70%. The limited bio-carties apparent volume of 15% was obtained from the experiments. The biomass on the bio-carries being over 6000 mg/L indicated that the bio-carries was fit for posed good resistance to the loading impact.