Department of Environmental Sciences and Engineering, Government College University Faisalabad, Faisalabad 38000, Pakistan; École Polytechnique Fédérale de Lausanne (EPFL), School of Architecture, Civil and Environmental Engineering (ENAC), Laboratory of Ecological Systems (ECOS), Bâtiment GR, Station 2, CH-1015 Lausanne, Switzerland; WSL Swiss Federal Institute for Forest, Snow and Landscape Research, Site Lausanne, Station 2, Case Postale 96, CH-1015 Lausanne, Switzerland.
Department of Environmental Sciences and Engineering, Government College University Faisalabad, Faisalabad 38000, Pakistan.
Sci Total Environ. 2018 Apr 1;619-620:517-527. doi: 10.1016/j.scitotenv.2017.11.143. Epub 2017 Nov 29.
A field study was conducted to test the potential of 5-year consecutive application of fresh industrial sludge (FIS) and composted industrial sludge (CIS) to restore soil functions at surface (0-15cm) and subsurface (15-30cm) of the degraded agricultural land. Sludge amendments increased soil fertility parameters including total organic carbon (TOC), soil available nitrogen (SAN), soil available phosphorus (SAP) and soil available potassium (SAK) at 0-15cm depth. Soil enzyme activities i.e. dehydrogenase (DHA), β-glucosidase (BGA) and alkaline phosphatase (ALp) were significantly enhanced by FIS and CIS amendments in surface soil. However, urease activity (UA) and acid phosphatase (ACp) were significantly reduced compared to control soil. The results showed that sludge amendments significantly increased microbial biomass nitrogen (MBN) and microbial biomass phosphorus (MBP) at both soil depth, and soil microbial biomass carbon (MBC) only at 0-15cm depth. Significant changes were also observed in the population of soil culturable microflora (bacteria, fungi and actinomycetes) with CIS amendment in surface soil suggesting persistence of microbial activity owing to the addition of organic matter source. Sludge amendments significantly reduced soil heavy metal concentrations at 0-15cm depth, and the effect was more pronounced with CIS compared to unamended control soil. Sludge amendments generally had no significant impact on soil heavy metal concentrations in subsoil. Agronomic viability test involving maize was performed to evaluate phytotoxicity of soil solution extract at surface and sub-surface soil. Maize seeds grown in solution extract (0-15cm) from sludge treated soil showed a significant increase of relative seed germination (RSG), relative root growth (RRG) and germination index (GI). These results suggested that both sludge amendments significantly improved soil properties, however, the CIS amendment was relatively more effective in restoring soil functions and effectively immobilizing wastewater derived heavy metals compared to FIS treatment.
一项田间研究旨在测试连续 5 年施用新鲜工业污泥（FIS）和堆肥工业污泥（CIS）对退化农田表层（0-15cm）和亚表层（15-30cm）土壤功能恢复的潜力。污泥改良剂增加了土壤肥力参数，包括总有机碳（TOC）、土壤有效氮（SAN）、土壤有效磷（SAP）和土壤有效钾（SAK）在 0-15cm 深度。FIS 和 CIS 改良剂显著增强了表层土壤中土壤酶活性，如脱氢酶（DHA）、β-葡萄糖苷酶（BGA）和碱性磷酸酶（ALp）。然而，与对照土壤相比，脲酶活性（UA）和酸性磷酸酶（ACp）显著降低。结果表明，污泥改良剂显著增加了两个土壤深度的微生物生物量氮（MBN）和微生物生物量磷（MBP），而仅在 0-15cm 深度增加了土壤微生物生物量碳（MBC）。在表层土壤中添加 CIS 还观察到土壤可培养微生物群落（细菌、真菌和放线菌）的数量发生了显著变化，表明由于添加了有机质源，微生物活性持续存在。污泥改良剂显著降低了 0-15cm 深度的土壤重金属浓度，与未改良对照土壤相比，CIS 的效果更为明显。污泥改良剂一般对亚表层土壤重金属浓度没有显著影响。在表层和亚表层土壤中进行了涉及玉米的农艺可行性试验，以评估土壤溶液浸提液的植物毒性。在污泥处理土壤的浸提液（0-15cm）中生长的玉米种子的相对种子发芽率（RSG）、相对根生长率（RRG）和发芽指数（GI）均显著增加。这些结果表明，两种污泥改良剂均显著改善了土壤性质，但与 FIS 处理相比，CIS 改良剂在恢复土壤功能和有效固定废水衍生重金属方面更为有效。
