de Jonge H, de Jonge L W, Blicher B W, Moldrup P
Danish Institute of Agricultural Sciences, Dep. of Crop Physiology and Soil Science, Research Centre Foulum, P.O. Box 50, DK-8830 Tjele, Denmark.
J Environ Qual. 2002 Nov-Dec;31(6):1963-71. doi: 10.2134/jeq2002.1963.
Municipal sewage sludge is often used on arable soils as a source of nitrogen and phosphorus, but it also contains organic contaminants that may be leached to the ground water. Di(2-ethylhexyl)phthalate (DEHP) is a priority pollutant that is present in sewage sludge in ubiquitous amounts. Column experiments were performed on undisturbed soil cores (20-cm depth x 20-cm diameter) with three different soil types: a sand, a loamy sand, and a sandy loam soil. Dewatered sewage sludge was spiked with 14C-labeled DEHP (60 mg kg(-1)) and bromide (5 g kg(-1)). Sludge was applied to the soil columns either as five aggregates, or homogeneously mixed with the surface layer. Also, two leaching experiments were performed with repacked soil columns (loamy sand and sandy loam soil). The DEHP concentrations in the effluent did not exceed 1.0 microg L(-1), and after 200 mm of outflow less than 0.5% of the applied amount was recovered in the leachate in all soils but the sandy loam soil with homogeneous sludge application (up to 3.4% of the applied amount recovered). In the absence of macropore flow, DEHP in the leachate was primarily sorbed to mobilized dissolved organic macromolecules (DOM, 30.3 to 81.3%), while 2.4 to 23.6% was sorbed to mobilized mineral particles. When macropore flow occurred, this changed to 16.5 to 37.4% (DOM) and 36.9 to 40.6% (mineral particles), respectively. The critical combination for leaching of considerable amounts of DEHP was homogeneous sludge application and a continuous macropore structure.
城市污水污泥常被用作耕地土壤的氮磷来源，但它也含有可能会渗入地下水的有机污染物。邻苯二甲酸二（2-乙基己基）酯（DEHP）是一种优先污染物，在污水污泥中普遍存在。对三种不同土壤类型（砂土、壤质砂土和砂壤土）的原状土柱（深度20厘米×直径20厘米）进行了柱实验。将脱水污水污泥与14C标记的DEHP（60毫克/千克）和溴化物（5克/千克）混合。污泥以五种团聚体的形式施用于土柱，或与表层土壤均匀混合。此外，还对重新装填的土柱（壤质砂土和砂壤土）进行了两次淋溶实验。流出液中的DEHP浓度不超过1.0微克/升，在流出200毫米后，除了均匀施用污泥的砂壤土（回收量高达施用量的3.4%）外，所有土壤中淋滤液中回收的施用量均不到0.5%。在没有大孔隙流的情况下，淋滤液中的DEHP主要吸附在可移动的溶解有机大分子（DOM，占30.3%至81.3%）上，而2.4%至23.6%吸附在可移动的矿物颗粒上。当出现大孔隙流时，这一比例分别变为16.5%至37.4%（DOM）和36.9%至40.6%（矿物颗粒）。大量DEHP淋溶的关键组合是均匀施用污泥和连续的大孔隙结构。
