Gwenzi W, Munondo R
Soil Science & Plant Nutrition, School of Earth & Geographical Sciences, University of Western Australia, Crawley, Perth, WA, Australia.
Water Sci Technol. 2008;58(12):2443-52. doi: 10.2166/wst.2008.583.
The study investigated the effects of 26 years of effluent irrigation on chemical and bacteriological quality of shallow (<3.0 m) groundwater. Annual loading rates for N and P exceeded pasture requirements, while trace metals were either lower or higher than guideline limits. Effluent irrigation removed TN (44-71%), TP (80%), Cr (96%) and coliform bacteria (87-99.9%) while Zn, Cu and Cd removal was negligible probably due to their enhanced mobility. Analysis of groundwater samples from effluent-irrigated and non-irrigated control sites showed that effluent irrigation increased the levels of all measured parameters compared to the control. Average groundwater quality parameters from effluent-irrigated sites compared to the control were: pH (6.1 vs. 5.7), EC (0.71 vs. 0.53 dS m(-1)), concentrations (mg L(-1)) for TP (2.3 vs. 0.3), DP (1.0 vs. 0.1), TN (15.1 vs. 2.5), NH(4)-N (2.6 vs. 0.5), NO(3)-N (4.1 vs. 1.3), Zn (0.4 vs. 0.05), Cu (0.13 vs. 0.02), Cd (0.05 vs. 0.01) and Cr (0.06 vs. 0.03). Across effluent-irrigated sites, FC and TC were 25 and 288 cfu/100 ml, respectively, versus nil for the control. Overall, effluent irrigation led to groundwater contamination by N, P, trace metals and coliform bacteria, which could threaten the long-term sustainability of the practice.
该研究调查了26年污水灌溉对浅层（<3.0米）地下水化学和细菌学质量的影响。氮和磷的年负荷率超过了牧场需求，而微量金属含量要么低于要么高于指导限值。污水灌溉去除了总氮（44 - 71%）、总磷（80%）、铬（96%）和大肠菌（87 - 99.9%），而锌、铜和镉的去除量可忽略不计，这可能是由于它们的迁移性增强。对污水灌溉区和非灌溉对照区地下水样本的分析表明，与对照相比，污水灌溉提高了所有测量参数的水平。污水灌溉区与对照区的平均地下水质量参数如下：pH值（6.1对5.7）、电导率（0.71对0.53 dS m(-1)）、总磷浓度（mg L(-1)）（2.3对0.3）、溶解性总磷（1.0对0.1）、总氮（15.1对2.5）、铵态氮（2.6对0.5）、硝态氮（4.1对1.3）、锌（0.4对0.05）、铜（0.13对0.02）、镉（0.05对0.01）和铬（0.06对0.03）。在污水灌溉区，粪大肠菌群和总大肠菌群分别为25和288 cfu/100 ml，而对照区为零。总体而言，污水灌溉导致了氮、磷、微量金属和大肠菌对地下水的污染，这可能威胁到这种做法的长期可持续性。
