Pilot-scale washing of metal contaminated garden soil using EDTA
- 作者：David Voglar ; Domen Lestan ; domen.lestan@bf.uni-lj.si
- 关键词：Contaminated soil ; Toxic metals ; EDTA ; Pilot scale remediation
- 刊名：Journal of Hazardous Materials
- 出版年：2012
- 期刊代码：50_03043894
- 类别：ce
- 出版时间：15 May, 2012
- 卷：215-216
- 期：Complete
- 页码：32-39
- 文件大小：570 K
摘要
Ten batches (75 kg each) of garden soil with >50%of silt and clay and average 1935 mg kg鈭? Pb, 800 mg kg鈭? Zn, 10 mg kg鈭? Cd and 120 mg kg鈭? As were remediated in a pilot-scale chemical extraction plant. Washing with 60 mmol ethylenediaminetetraacetic acid (EDTA) per kg of soil on average removed 79, 38, 70, and 80%of Pb, Zn, Cd and As, respectively, and significantly reduced the leachability, phyto-accessibility and oral-availability of residual toxic metals, as assessed using deionised water, toxicity characteristic leaching procedure (TCLP), diethylenetriamine pentaacetic acid extraction (DTPA) and physiologically based extraction test (PBET) tests. The used soil washing solution was treated before discharge using an electrochemical advanced oxidation process with graphite anode: EDTA was removed by degradation and toxic metals were electro-precipitated onto a stainless steel cathode. The novelty of the remediation technique is separation of the soil from the washing solution and soil rinsing (removal of mobilized contaminants) carried out in the same process step. Another novelty is the reuse of the soil rinsing solution from the previous batch for cleansing the soil sand, soil rinsing and for preparation of the washing solution in subsequent batches. The cost of energy and material expenses and disposal of waste products amounted to approximately 75鈧?#xA0;ton鈭? of soil.