摘要
拜耳法赤泥产量大且成分复杂,碱性强,难处理,易引起环境污染。而近年土壤重金属污染形势严峻,儿童血铅中毒事件时有发生。针对上述问题,以拜耳法赤泥为主要原料,加入少量水泥等添加剂改性制备赤泥基颗粒材料,并将其应用于土壤中铅的稳定化。结果表明,材料配方为2%水泥+5%石膏+5%粉煤灰+5%磷酸二氢钙+83%,水灰比为0.5,圆盘造粒参数为28°<α<40°、20r·min^(-1)<R<40r·min^(-1)时为颗粒最佳条件。按此配方制备的赤泥颗粒对铅污染浓度为100、250、500和800mg·kg^(-1)的模拟污染土壤进行修复,当投加5%的颗粒,稳定10d后,土壤中铅的生物可利用态分别降低了72.52%、65.38%、64.73%和40.03%,而残渣态增加了43.4%、35.13%、43.42%和43.97%,有随着污土浓度增加而增加的趋势,表明赤泥制备成颗粒材料后能有效稳定土壤中不同浓度的铅。
A large amount of Bayer process red mud is produced every years. It is difficult to handle due to its complicate composition and alkalinity, causing environment pollution. Soil heavy metal pollution is grim in recent years, leading to child blood lead poisoning. Regarding the issue above, we prepared red mud granules by using the Bayer process red mud as the main raw material, adding a little cement and other modified additives, followed by the applicationin stabilizing the soil lead. The results indicated that the optimized parameters for the modification are materials of 2% cement ＋ 5% gypsum ＋ 5% fly ash ＋ 5% calcium dihydrogen phosphate ＋ 83% red mud, water cement ratio of 0.5, the disc granulation parameter of 28°α 40°and 20 r·min^（-1）R 40 r·min^（-1）. The red mud particles prepared according to the optimized parameters are used to repair simulated soil with lead pollution at four different concentration which are 100, 250, 500 and 800 mg·kg^（-1）. When dosing 5% red mud particles followed by10 days＇ immobilization, the bioavailability of lead was reduced 72.52%、65.38%、64.73% and 40.03%, while the residual state increased by 43.4%, 35.13%, 43.42% and 43.97%, respectively. The residual state of soil lead has a tendency to increase as the pollution concentration of soil increase, indicating that red mud prepared into a granular material can effectively stabilize the different concentrations of lead in the soil.
作者
杨慧珠
程乾坤
王新璋
陈惠康
张红云
黄雄飞
杨晓芳
汤叶涛
石太宏
YANG Huizhu1,CHENG Qiankun1,WANG Xinzhang2,CHEN Huikang2,ZHANG Hongyun1,HUANG Xiongfei1,3,YANG Xiaofang2,TANG Yetao1,3,SHI Taihong1,3(1. School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou 510006, China2. Zhongdian Investment Shanxi Aluminum Co. Ltd., Yuanping 034100, China 3. Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, Guangzhou 510006, Chin)
出处
《环境工程学报》
CAS
CSCD
北大核心
2018年第4期1171-1181,共11页
Chinese Journal of Environmental Engineering
基金
广东省科技开发协作项目(71010623)
关键词
赤泥
颗粒
土壤铅
稳定化
red mud
granules
Pb in soil
stabilization
