填料在净化污水过程中渗透性能变化趋势的研究

Study on the trend of variation of filter media permeability in purifying wastewater

选取腐殖垃圾和砂以及两者质量比分别为4∶1、3∶2、2∶3的混合物共5种填料,在1.0m/d的水力负荷下,进行人工快速渗滤系统净化生活污水的试验,研究填料在进水过程中渗透性能的变化趋势。结果表明,腐殖垃圾的初始饱和水力渗透系数(K)最大,为3.32×10-2cm/s,而砂的初始K只有5.14×10-3cm/s,腐殖垃圾含量越大的混合物其初始K也越大。在净化污水的过程中,5种填料的K逐渐减小,腐殖垃圾含量越大的混合物其K降幅也越大。随着进水时间的延长,各个填料柱填料层50～250mm处的水头损失占总水头损失(填料层50～450mm处)的比例均逐渐增加,最终各个填料柱均发生堵塞,堵塞均发生在填料层50mm以上范围内。

Five kinds of filter media were utilized to study the permeability change of fiher media in the simula ted rapid infiltration system to treat sewage at hydraulic loading rate of 1.0 m/d. The media include aged refuse, river sand and their mixtures with the mass ratio of 4 ： 1, 3 ： 2, 2 ： 3. The results showed that aged refuse has the biggest initial rate K of 3.32×10 ^-2 cm/s, but river sand has only 5.14×10^-3 cm/s. The greater the proportion of aged refuse is in the filter media, the higher the initial K value. In the process of sewage purification, each K value of five filter media decreased. The higher the content of aged refuse in the filter media, the greater the K value drops. With the extension of treatment time, the upper head loss（50 250 mm）of the total head loss（50 450 mm）in each system gradually increased. Every system plugged uhimately, The plugging all happened above depth of 50 mm.