UASB-生物接触氧化处理小麦淀粉废水的研究

Research on the Oxidation Treatment of the Wheat Starch Wastewater by UASB-biological Contactor

[目的]研究厌氧-好氧组合工艺处理小麦淀粉废水的工艺参数,为小麦类食品加工行业的废水处理工艺提供参考。[方法]以目前最具代表性的UASB-生物接触氧化组合工艺处理小麦淀粉废水,研究其最佳工艺参数。[结果]单因素最佳条件为:UASB反应器流量50.0L/h,水力停留时间4.0h;生物接触氧化池曝气量1.2m3/h,水力停留时间1.0h。其UASB反应器的CODCr去除率可达75%～80%,生物接触氧化池可达70%～80%。在单因素试验基础上进行了正交试验,结果表明,当UASB反应器的水力停留时间为3.0h时,其出水CODCr值可降至600mg/L,去除率达到70%～80%;然后使出水通过生物接触氧化池处理后,其出水CODCr值可降至200mg/L左右,去除率达到65%～75%。UASB-生物接触氧化组合工艺处理小麦淀粉废水的最佳工艺参数为:UASB反应器水力停留时间2.0h,UASB反应器流量45.0L/h,生物接触氧化池水力停留时间1.0h,生物接触氧化池曝气量1.2m3/h。该组合工艺的CODCr去除率为92.5%。[结论]食品加工行业的废水处理工艺采用以上工艺参数可以达到行业排放标准。

[Objective] The reference for the wastewater-treating in the industry of wheat food processing was provided through the study on the technical parameter in the treatment process of wheat starch wastewater with the combined technology of anaerobic-aerobic process. [Method] The oxidation process of UASB-biological contactor,a most representative combined technique,was applied for the treatment of the wastewater from wheat starch-processing to study the optimum processing parameter. [Results] The optimum condition from single-factor experiment was the flow rate of UASB reactor was 50.0 L/h with the time of hydraulic retention of 4.0 hours; the amount of the aeration in bio-contact oxidation pond was 1.2 m3/h with the time of hydraulic retention of 1.0 hour and the removal rate of CODCr in the UASB reactor was up to 75%-80% and in the bio-contact oxidation pond,70%-80%. The results from the orthogonal experiment based on single-factor test showed that the removal efficiency was 70%-80% when the time of hydraulic retention in the UASB reactor was 3.0 hours and its value of the water-exiting for CODCr might be reduced to 600 mg/L; then the value of the water-exiting for CODCr might be reduced to 200 mg/L or so after the effluent water treated by biological contact oxidation pond,and the removal rate was 65%-75%. The optimum parameters in the treatment of wheat starch wastewater with the UASB-biological contact oxidation process was：the time of hydraulic retention in UASB reactor,2.0 hours; the flow rate in UASB reactor,45.0 L/h; the time of hydraulic retention in bio-contact oxidation pond,1.0 hour and the aeration of bio-contact oxidation pond,1.2 m3/h. The removal rate of COD in the combined processing technique was 92.5%. [Conclusion] The processing parameters mentioned-above could be used for the waste water-treating in the food processing industry,which could promote the standard of the drainage wastewater being reached to that of the industry.