针对高浊山溪水的除浊工艺构建与效能研究

Construction and Performance of Turbidity Removal Process for High Turbidity Mountain Streams

针对西藏偏远农村地区山溪水雨季高浊问题,利用微电解自絮凝和直接过滤等方法,构建了无烟煤预过滤-微电解微絮凝-石英砂接触过滤组合工艺。考察了无烟煤预过滤单元在低滤速下的截污效果、微电解絮凝单元铁碳质量比对接触过滤单元浊度去除效果的影响,以及滤速对工艺运行效能的影响。结果表明,无烟煤预过滤单元截留了大部分3μm以上的杂质颗粒,预过滤后96.4%的杂质颗粒粒径集中在2~3μm;当铁碳质量比为5∶5和6∶4时该工艺除浊效果较好,浊度去除率分别为95.57%和96.75%。在铁碳质量比为6∶4、水力停留时间为3 min、滤速为3 m/h的条件下,该工艺的有效过滤周期能达到32 h,是滤速为6和9 m/h的2倍以上。试验采用单独水洗的反冲方式,反冲洗强度为20 L/(s·m^2),反冲洗时间为8 min。

In the remote rural areas of Tibet, to address the high turbidity in mountain streams during rainy season, an integrated filtration system using anthracite pretreatment -micro-electrolysis and flocculation -quartz sand contact filtration was constructed, based on the concepts of micro-electrolysis self-floceulation and direct filtration. The interception efficiency of the anthracite pre-filtration unit under low filtration rates, the effect of iron-carbon mass ratio of the micro-electrolysis flocculation unit on the turbidity removal in the contact filtration unit, and the influence of the filtration rate on the process effi- ciency were all investigated. The results showed that the anthracite pre-filtration unit retained most of the particles larger than 3 μm, and the particles with a particle size of 2 - 3 μm accounted for 96.4% of the total residual particles. When the mass ratio of iron to carbon was 5 ： 5 and 6 ： 4, the turbidity removal efficiencies were as high as 95.57% and 96.75% , respectively. With an iron-carbon mass ratio of 6 ： 4, a hydraulic retention time of 3 min, and a filtration rate of 3 m/h, the effective filtration cycle of the process reached 32 h, which was more than twice of that when using filtration rates of 6 or 9 m/h. The system was backwashed with 20 L/（ s ·m2 ） of water for 8 min.