玉米深加工行业废水回用于循环冷却系统的可行性研究

Research on the Feasibility of Reclaimed Water Reused for Circulated Cooling System in Corn Deep Processing Enterprises

通过对某大型玉米深加工企业排放废水的调研和取样分析,探讨了玉米深加工企业废水回用的可行性。结果表明,该企业废水水质特点为有机物、悬浮物和Cl-浓度高。采用曝气生物滤池(BAF)及膜生物反应器(MBR)深度处理企业总排出水及内循环反应器(IC反应器)出水的效果较好,但Cl-去除率较低。用旋转挂片法与扫描电子显微镜相结合对深度处理小试装置出水的腐蚀试验得出,BAF出水及MBR出水不能直接用于循环冷却系统补充水,其中Cl-是引起腐蚀的最主要因子。利用反渗透工艺处理MBR出水可将Cl-浓度降到0.5μg/L以下,使出水完全满足循环冷却系统补充水水质要求。成本分析表明,反渗透工艺处理后中水回用于循环冷却系统,可降低企业运行成本,具有一定的经济效益。

The investigation and analysis on the wastewater discharged from one large corn deep processing company were performed.It showed that the wastewater had high concentrations of organic matter,SS and chloride.Biological aerated filter（BAF） and membrane bio-reactor（MBR） were adopted to perform deep treatment for the wastewater from the total discharge outlet as well as from the IC reactor outlet.Both processes showed favorable wastewater treatment efficiency except for chloride removal.The rotary coupon method combined with scanning electron microscopy was used to perform corrosion test for the effluent from the lab-scale deep treatment facilities,to investigate the feasibilities of the effluents as supplementary water for circulated cooling system directly.The results indicate that the effluent from BAF and MBR cannot be used as supplementary water directly according to the conspicuous acceleration of chloride on corrosion process.Reverse osmosis could not only reduce chloride concentration to less than 0.5 μg/L,but also could meet requirements to reuse for circulated cooling system.Compared with the operational cost of the company,the reuse of the effluent from reverse osmosis process as supplementary water for circulated cooling system can save the cost and gain certain economic benefit.