摘要
研究脱硫石膏(flue-gas desulfurization gypsum,FGDG)对土壤磷流失的阻控效果,既有利于开拓FGDG资源化利用新途径,又有助于丰富农业面源磷流失控制工程技术。借助土柱淋溶试验和人工边坡降雨侵蚀模拟试验,针对上海某火电厂的FGDG,系统研究不同质量配比(0、1%、2.5%和5%)的FGDG对农田土壤的固磷效果及机理。结果表明:1)FGDG的Ca2+将溶解态P转化成难溶态P,并将土壤无机磷中的Ca2-P、Al-P转化成Ca8-P和Ca10-P,有效控制溶解态磷(total dissolved phosphorus,TDP)直接流失,与对照组相比,施加FGDG对淋洗土柱TDP流失的阻控率达到92.8%~94.8%,而添加FGDG的各处理间无显著差异(P>0.05);2)添加FGDG后,土壤的渗透性能和抗侵蚀能力极显著提高(P<0.05),1%~5%的FGDG可使土柱渗透性能提升近10倍,添加FGDG的各处理组间无显著差异(P>0.05),1%FGDG对坡面径流量的最大削减率为37.5%,对土壤侵蚀(泥沙流失)的最大削减率为59.5%,有利于控制泥沙结合态磷的流失;3)各FGDG处理对土柱中总磷(total phosphorus,TP)流失的阻控率为23.6%~79.5%,且随着配比增加而上升,与对照组相比,1%FGDG对人工边坡土壤TP流失的阻控率为61.5%。土壤流失的TDP量占流失TP的比例只有0.6%~6.1%,反映出改善土壤渗透性能、削减地表径流冲刷是FGDG控制P流失的主要机制,而Ca与P之间的沉淀反应属于从属机制。
Increased phosphorus （P） losses from land to waterbody via runoff and drainage are one of the important factorscausing eutrophication of surface waterbody. Flue gas desulfurization gypsum （FGDG） is a synthetic by-product generatedfrom the flue gas desulfurization process in coal power plants. Due to the high Ca2＋ content of FGDG it can potentially be usedto immobilize P in soils. To study the effects of FGDG on soil P losses, not only to open up a new way of FGDG resourceutilization, but also to enrich engineering technologies for controlling agricultural non-point source P load. In this study, soilcolumn leaching experiment and artificial soil slope ＆ rainfall simulation experiment were conducted to examine the impact ofFGDG which came from one of Shanghai coal-fired power plant, on the leaching and nmoff P losses from coastal plains soil ofChongming East Headland, Shanghai. Four mass rates of FGDG （0, 1%, 2.5% and 5%） were applied to soil column and twomass rates of FGDG （0 and I%） applied to artificial soil slope. The results indicated that： 1） Ca2＋ dissolved from FGDGtransformed water-soluble P to insoluble P in soil, and turned Ca2-P, A1-P into Cas-P and Ca2＋-P which were more inclined tofix in soil. Compared with the control group, the reduction rate of total dissolved phosphorus （TDP） loss of the soil columnsapplied with FGDG reached 92.8%-94.8% and there was no significant difference among three FGDG treatments （P〉0.05）. 2）FGDG significantly improved soil permeability and anti-erosion ability （P〈0.05）, 1%-5% FGDG made the saturatedpermeability of soil columns increase nearly 10 times, there was no significant difference among three FGDG treatments（/9〉0.05）. Compared with the non-FGDG slopes, 1% FGDG addition achieved the maximum runoff reduction rate of 37.5%,the maximum reduction rate of sediment loss of 59.5%. It was indicated that much adsorbed P on suspended sediment wasprevented from migrating along with surface runoff. 3） The reduction rate of TP
出处
《农业工程学报》
EI
CAS
CSCD
北大核心
2017年第3期148-154,共7页
Transactions of the Chinese Society of Agricultural Engineering
基金
环保公益性行业科研专项项目(NO.201109023-2)
关键词
土壤
磷
径流
脱硫石膏
土壤渗透性能
磷流失
阻控
soils
phosphorus
rtmoff
flue-gas desulfiarization gypsum
soil permeability
phosphorus loss
inhibiting
