Brookman S K E, Retter A R
Institute of Grassland and Environmental Research, North Wyke Research Station, Okehampton, Devon EX20 2SB, UK.
Environ Technol. 2005 Nov;26(11):1189-204. doi: 10.1080/09593332608618593.
Lysimeter experiments were conducted to determine the ability of different soils to reduce levels of biochemical oxygen demand (BOD) and concentrations of molybdate reactive phosphorus (MRP) and ammonium-N (NH4(+)-N) in dirty water and the impact of applications on nitrate leaching. An additional experiment investigated the effect of dirty water components on leaching quality. This information is required to assess the potential risk of dirty water applications on polluting groundwater and to assess the use of such soils in the development of treatment systems for dirty water. Intact and disturbed soil lysimeters, 0.5 and 1m deep were constructed from four soils; a coarse free-draining sandy loam, a sandy loam over soft sandstone, a calcareous silty clay over chalk and a sandy loam over granite. For the coarse free-draining sandy loam, lysimeters were also constructed from disturbed soil with and without the addition of lime, to assess if this could increase phosphorus immobilisation. Levels of BOD and concentrations of MRP, NH4(+)-N and nitrate (NO3(-)-N) of leachates were measured following dirty water applications at 2 and 8 mm day(-1) under laboratory conditions. Under the daily 2mm application, all soils were effective at treating dirty water, reducing concentrations of BOD, MRP and NH4(+)- N by > or = 98% but NO3(-)-N concentrations increased up to 80 mg l(-1) from the 0.5 m deep lysimeters of the sandy loam over granite. Soils were less effective at reducing levels of BOD, MRP and NH4(+)- N at the 8 mm daily rate of application, with maximum NO3(-)-N concentrations of leachates of 200 mg l(-1) from disturbed soils.
进行了蒸渗仪实验，以确定不同土壤降低污水中生化需氧量（BOD）水平、钼酸盐反应性磷（MRP）浓度和铵态氮（NH4(+)-N）的能力，以及污水施用对硝酸盐淋失的影响。另一个实验研究了污水成分对淋失质量的影响。需要这些信息来评估污水施用对污染地下水的潜在风险，并评估此类土壤在污水处理系统开发中的用途。用四种土壤构建了深度为0.5米和1米的完整和扰动土壤蒸渗仪；一种粗质地、排水良好的砂壤土，一种覆盖在软砂岩上的砂壤土，一种覆盖在白垩土上的钙质粉质粘土，以及一种覆盖在花岗岩上的砂壤土。对于粗质地、排水良好的砂壤土，还从添加和未添加石灰的扰动土壤中构建了蒸渗仪，以评估这是否能增加磷的固定。在实验室条件下，以2毫米/天和8毫米/天的速率施用污水后，测量渗滤液中的BOD水平、MRP、NH4(+)-N和硝酸盐（NO3(-)-N）浓度。在每天2毫米的施用量下，所有土壤都能有效处理污水，将BOD、MRP和NH4(+)-N的浓度降低≥98%，但从覆盖在花岗岩上的砂壤土的0.5米深蒸渗仪中，NO3(-)-N浓度增加到了80毫克/升。在每天8毫米的施用速率下，土壤在降低BOD、MRP和NH4(+)-N水平方面效果较差，扰动土壤渗滤液中NO3(-)-N的最大浓度为200毫克/升。
