Department of Agronomy, Biotechnical Faculty, University of Ljubljana, Jamnikarjeva 101, SI-1001 Ljubljana, Slovenia.
Waste Manag. 2010 Nov;30(11):2130-6. doi: 10.1016/j.wasman.2010.05.004. Epub 2010 Jul 15.
The effects of wastewater application on electrical conductivity, water retention and water repellency of soils planted with Populus deltoides (eastern cottonwood) and irrigated with different concentrations of landfill leachate and compost wastewater, tap water and nutrient solution were evaluated. Substrate water content at field capacity (-0.033 MPa) and at permanent wilting point (-1.5 MPa) was determined with a pressure plate extractor to assess available water capacity of the substrate. A water drop penetration test was used to determine substrate water repellency. The biomass of nutrient and landfill leachate treatments was significantly (P<0.05) greater compared to the tap water and compost wastewater treatments. All treatments increased substrate water content at field capacity and at permanent wilting point. Landfill leachate significantly increased available water capacity (up to 52%); treatment with compost wastewater significantly decreased it (25-47%). All substrates showed increased water repellency after the experiment at field capacity and permanent wilting point comparing to the original substrate. The strongest influence on water repellency at both field capacity and permanent wilting point showed irrigation with compost wastewater and tap water. Pronounced influence on substrate's water repellency of compost wastewater could be contributed to a high content of dissolved organic carbon, whereas Mg and Ca cations caused flocculation and consequent water repellency of the substrate irrigated with tap water. The results indicate that soil physical characteristics must be closely monitored when landfill leachate and compost wastewater are used for irrigation to avoid long term detrimental effects on the soil, and consequently on the environment. Due to the complexity of the compost wastewater quality the latter should be applied on open fields only after prior pre-treatment to reduce dissolved organic carbons, or alternatively, compost wastewater should be added only intermittently and in diluted ratios.
评估了不同浓度的垃圾渗滤液和堆肥废水、自来水和营养液灌溉的种植了杂交杨（东部棉白杨）的土壤的电导率、持水能力和疏水性能的变化。采用压力板提取器测定田间持水量（-0.033 MPa）和永久萎蔫点（-1.5 MPa）下的基质含水量，以评估基质的有效含水量。采用水滴渗透试验测定基质的疏水性。与自来水和堆肥废水处理相比，营养和垃圾渗滤液处理的生物量显著（P<0.05）更高。所有处理均增加了田间持水量和永久萎蔫点下的基质含水量。垃圾渗滤液显著增加了有效含水量（高达 52%）；而堆肥废水处理则显著降低了有效含水量（25-47%）。与原始基质相比，所有基质在田间持水量和永久萎蔫点下的疏水性在实验后均有所增加。与自来水相比，用堆肥废水灌溉对田间持水量和永久萎蔫点的疏水性影响最大。堆肥废水中溶解有机碳含量高，可能是导致基质疏水性增强的主要原因，而用自来水灌溉的基质中 Mg 和 Ca 阳离子则会引起絮凝，从而导致其疏水性增强。结果表明，在使用垃圾渗滤液和堆肥废水进行灌溉时，必须密切监测土壤的物理特性，以避免对土壤产生长期的不利影响，进而对环境产生不利影响。由于堆肥废水的复杂性，在对其进行预处理以降低溶解有机碳后，应仅将其施用于开阔地；或者，应间歇性地、以稀释的比例添加堆肥废水。
