含泥黄河水人工滤床技术参数的试验研究

Study on technical parameters of artificial filter bed for mud water from the Yellow River

以黄河中游柳林段滩地自然堆积砂砾石为研究对象,通过系统试验,分别对无砂混凝土板、大粒径卵石覆盖层与剔除过大过小粒径后的黄河滩地自然级配砂砾石组合的过滤体,以及细颗粒介质、土工布、砂砾石复合过滤体的技术参数进行了分析比较,提出了满足取水流量和饮用水浊度要求的人工滤床过滤体和支撑体的技术参数。研究结果表明:无砂混凝土板具有较好的拦泥作用,但淤泥会在无砂混凝土板的孔隙中大量淤积,反冲洗后渗流能力恢复率低;大粒径卵石覆盖层拦泥过滤层的拦泥效果不如无砂混凝土方案好,反冲洗后渗流能力恢复率也较低,不宜采用;0.25～1.0mm细颗粒介质与双层土工布复合过滤体,水质满足要求、渗透系数较大,又便于淤泥的机械和水清洗,是一种值得推荐的过滤体型式;等粒径介质分层填筑支撑层过渡条件好,滤层结构、渗流更为稳定,是一种值得推荐的滤床支撑层。

Taking the naturally accumulated sandy gravel from the benchland of Liulin reach in the midYellow River as the study subject, the technical parameters of nonfine concrete board, large particle size grait blanket combined with the natural graduation grit which eliminated the oversize and undersize group, as well as compound filter body combined with fine particulate medium geotextile, were analysed re spectively and compared through a systematic tests. The technical parameters of the filter body of artificial filter bed and support body which meet the standards for water intaking and drinking water turbidness were put forward. The results show that （a） nonfine concrete board has a good effect for mud blocking, but the sludge may be deposited in the holes of the nonfine concrete, and the recovery rate of its seepage ca pacity after back wash is lower; （b） the effect of mud blocking of grait blanket with large particle size is less than the nonfine concrete and the recovery rate of seepage capacity after back wash is also lower, so it is not suitably used; （c） the double geotextile compound filter body with 0.25~l.Omm fine particulate me dium and a bigger permeability coefficient, not only meets the demands of water quality, but also is conve nient for the sludge cleaning in mechanical way and by water, which is a recommendable filter body type; （d） the support layer filling delamination by the same particle size medium has a good transition condition with more stable filter layer structure and seepage, which is a recommendable filter bed support layer.