城市再生水灌溉对农田环境的影响评价研究

The Research on Influence Evaluation of the City Epigenetic Water to Farmland

在天津市武清区设立利用城市再生水进行农田灌溉示范区。试验时间为2003—2006年,每年种植小麦、玉米两茬作物,主要进行再生水灌溉农田的土壤、农产品及地下水安全性监测试验。结果表明,再生水灌区的土壤有机质、总氮等营养成分和细菌总数、总孔隙度均有所升高,且细菌总数和总氮的变化显著,pH、盐分升高不明显;使用再生水对土壤中重金属含量及示范区浅层地下水水质未造成明显影响。试验期间小麦、玉米的样品中重金属含量均低于相应的食品卫生标准。不同水质对农产品及作物秸秆中重金属的影响不显著,使用再生水灌溉的单位面积产量和千粒重明显高于使用地下水。

The demonstration plot was established in Wuqing area in Tianjin city, where the renovated water from sewage treatment plant in economic development zone was used in irrigating farmland after aeration in store pool. The experiments were carried out to investigate the effects of irrigation with the renovated water on farmland soil and the safety of agricultural product and underground water under wheat-maize growing system in 2003-2006. The results indicated that the soil nutrients, such as soil organic matter and total nitrogen, total number of bacteria and total porosity increased somewhat, and total nitrogen and total number of bacteria changed significantly, but pH and salinity showed no significant increase. The content of soil heavy metals and shallow underground water quality were not greatly influenced by making use of the renovated water for irrigation. The content of heavy metal in grain and straw of wheat and maize was not significantly influenced by irrigation water quality, which was below the corresponding standard of food hygiene. The yield per acre and one-thousand grain weight of wheat and maize irrigated with renovated water were higher than those irrigated with underground water.