采用预沉淀与砂滤结合的方法处理蔬菜腌制厂清洗废水．通过小试实验和中试实验研究探讨滤料粒径、滤层厚度与滤料有效粒径比值(L/d10)及滤速对处理效果的影响，比较研究不同因素在放大过程中的规律，确定适宜的中试操作条件．实验结果表明：滤料粒径越小，对浊度的去除效果越好，粒径为0.7～1.2,mm 的滤料对废水的浊度平均去除率可达85.09%；L/d10越大，过滤周期越长，周期产水量越高．小试中L/d10由60.4增大为120.1，对应的过滤周期、周期产水量分别由17,h、17.68,m3/m2增长到35,h、36.4,m3/m2．滤速越小，过滤周期越长．滤速由2.08,m/h 减小为0.52,m/h，对应的过滤周期由11,h 增长到82,h．中试实验设计条件为：L/d10＝1,100，滤速 v＝7.5,m/h．废水处理后，浊度、悬浮物(SS)的去除率分别为82.56%、83.72%，出水水质满足再生水用作工业回用水水源的水质要求．同时此方法流程简单、容易操作，为探索低成本高含盐废水处理技术提供了实验依据．%Pretreatment of washing wastewater in vegetable curing factories was done through a combined process of pre-cipitation and sand filtration. The effect of particle size of the filter material,the ratio of bed thickness to effective size of the filter material(L/d10)and filtering velocity to the filter function were studied by laboratory and pilot tests. The best pilot oper-ating conditions were chosen through the comparison between laboratory tests and enlarged experiments. The results showed that:the removal of turbidity increased with the decrease of particle size of the filter material;the removal of turbidity was up to 85.09%when the particle size of the filter material was 0.7~1.2,mm. The filter cycle and the periodic quantity of water produced increased with the increasing of L/d10. The increase was from 17,h ,17.68,m3/m2,at 60.4(L/d10)to 35,h , 36.40,m3/m2,at 120.1(L/d10),respectively. The filter cycle increased from 11,h at 2.08,m/h(filtering velocity)to 82,h at 0.52,m/h(filtering velocity) with the decrease of filtering velocity. When the pilot operating conditions were 1,100(L/d10)and 7.5,m/h(filtering velocity),the removal efficiency of turbidity,suspended substance(SS)was 82.56% and 83.72%,respectively. The production quality of the effluent could meet the standards of the reclaimed water to be reused in industry. At the same time,this method was simple and easy to operate. The research can thus lay a foundation for the explo-ration of low-cost treatment technology for the high-salt wastewater.
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