Environmental Engineering Group, Department of Civil, Structural and Environmental Engineering, University of Dublin, Trinity College, Dublin 2, Ireland.
J Contam Hydrol. 2012 Nov;142-143:126-39. doi: 10.1016/j.jconhyd.2011.12.003. Epub 2012 Jan 3.
An extensive field study on percolation areas receiving both septic tank and secondary treated on-site effluents from single houses in Ireland was carried out to investigate the attenuation capacity of highly permeable subsoils with respect to E. coli bacteria and spiked bacteriophages (MS2, ΦX174 and PR772). The development of biomats across the percolation areas receiving the secondary effluent was restricted compared to the percolation area receiving septic tank effluent, promoting a much higher areal hydraulic loading which created significant differences in the potential microbiological loading to groundwater. Greatest E. coli removal in the subsoil occurred within the first 0.35 m of unsaturated subsoil for all effluent types. Analysis showed, however, that more evidence of faecal contamination occurred at depth in the subsoils receiving secondary treated effluents than that receiving septic tank effluent, despite the lower bacterial influent load. All three bacteriophages were reduced to their minimum detection limit (<10 PFU/mL) at a depth of 0.95 m below the percolation trenches receiving septic tank effluent, although isolated incidences of ΦX174 and PR772 were measured below one trench. However again, slightly higher breakthroughs of MS2 and PR772 contamination were detected at the same depth under the trenches receiving secondary treated effluent.
在爱尔兰，对接收来自单个房屋的化粪池和二级处理现场废水的渗透区进行了广泛的实地研究，以调查高度渗透的底土对大肠杆菌和噬菌体（MS2、ΦX174 和 PR772）的衰减能力。与接收化粪池废水的渗透区相比，接收二级处理废水的渗透区中生物膜的发展受到限制，促进了更高的区域水力负荷，从而对地下水的潜在微生物负荷产生了重大影响。对于所有废水类型，大肠杆菌在不饱和底土的前 0.35 米范围内的去除率最高。然而，分析表明，尽管细菌进水负荷较低，但在接收二级处理废水的底土中，在更深的地方发现了更多的粪便污染证据，而不是接收化粪池废水的底土。所有三种噬菌体在接收化粪池废水的渗沟下方 0.95 米的深度处均减少到最低检测限(<10 PFU/mL)，尽管在一个渗沟下方仍测量到了单独的ΦX174 和 PR772。然而，在接收二级处理废水的渗沟下方相同深度处，又检测到了稍高的 MS2 和 PR772 污染的突破。
