摘要
针对城市污泥组成成分的特点,以科尔沁沙地土壤为研究对象,分析其应用于沙地土壤改良的可行性及对地下水的潜在风险。室内土柱淋溶模拟试验研究结果表明,不同的污泥施入量可明显增加沙化土壤表层中氮磷养分含量,提高沙化土壤质量,同时污泥施用量对淋出液中氮磷养分含量存在显著影响,且氮素的淋溶风险大于磷素。当污泥施用量为30t/hm2时,淋出液中总氮(TN)、总磷(TP)含量与不施用污泥的对照处理间未存在显著差异,且随淋洗次数的增加,TN含量呈现先下降后趋于稳定的变化趋势,TP含量呈现逐渐下降,而硝态氮(NO3--N)含量较不施用污泥的对照处理增加11%～33%,但与其差异不显著(P>0.05)。当污泥施用量为60,90t/hm2时,淋洗液中TN和TP含量显著增加(P<0.01),随淋洗次数的增加,TN和NO3--N含量呈现先上升后趋于稳定的变化趋势,而NO3--N含量在第3次淋洗后均超出地表水环境质量标准中Ⅲ类水质标准限值(20mg/L),对地下水体污染风险增加。合理控制污泥施用量不仅可以实现城市污泥的资源化利用,同时也可控制其对地下水的影响。
The feasibility of sewage sludge applied to Kerqin sandy soil amendment and the potential risks to groundwater in areas were investigated. A soil column leaching experiment was carried out. The results showed that the different addition of the sewage sludge to soil significantly increased the content of nitrogen and phosphorus in topsoil and improved the sandy soil quality. The sewage sludge application rates had a significant effect on nitrogen and phosphorus concentrations in leacheate, but the leaching risk of nitrogen to groundwater was higher than that of phosphorus. The concentrations of total nitrogen （TN） and total phosphorus（TP） in leacheate after applied sewage sludge with 30 t/hm2 had no significant difference compared with the control treatment. The total nitrogen concentration initially decreased and then stabilized with leaching times, while total phosphorus concentration little increased at the fourth leaching after decreased in the beginning and then decreased slowly with leaching times. The nitrate concentrations were enhanced by 11 0//00~33~ compared to the control treatment and there was not significant difference between them（P^0.05）. The concentrations of nitrogen and phosphorus in leacheate after applied 60 t/hme and 90 t/hm2 were significantly increased（P^0.01）. The concentrations of nitrate and total nitrogen applied sewage sludge 60 t/hmz and 90 t/hme increased in the beginning and then decreased with leaching times. The nitrateconcentrations were greater than the threshold values for Environmental Quality Standards for surface water in China after the third leaching, increasing a potential contamination risk to groundwater. The results indicated that application of sewage sludge to a sandy soil might not cause a risk in terms of groundwater contamination, with the application rate of 30 t/hm2.
出处
《水土保持学报》
CSCD
北大核心
2013年第4期93-97,102,共6页
Journal of Soil and Water Conservation
基金
国家水体污染控制与治理科技重大专项(2012ZX7505-001)
国家自然科学基金项目(41071317)
沈阳市科技局计划项目(F10-205-1-64)
辽宁省科学技术基金项目(20092013)
辽宁省百千万人才工程资助项目(2008921082)
哈尔滨工业大学城市水资源与水环境国家重点实验室开放基金项目(HC200902)
格平绿色助学行动辽宁环境科研‘123工程’基金项目(CEPF2009-123-1-4)
国家科技支撑计划项目(2010BAC69B02-01-04)
关键词
城市污泥
沙地土壤
淋溶
硝态氮
磷
环境风险
sewage sludge
sandy soil
leaching
nitrate
phosphorus~ environmental risk
