Iron turning waste: Low cost and sustainable permeable reactive barrier media for remediating dieldrin, endrin, DDT and lindane in groundwater. (15th November 2021)

• Record Type: Journal Article
• Authors: Abbas, Tauqeer; Wadhawan, Tanush; Khan, Asad; McEvoy, John; Khan, Eakalak
• Is Part Of: Environmental pollution. Volume 289(2021)
• Publication Date: 2021-11-15
• Subjects: Chlorinated pesticides -- Degradation by-products -- Degradation pathways -- Groundwater remediation -- Iron turning waste; Pollution -- Periodicals; Pollution -- Environmental aspects -- Periodicals; Environmental Pollution -- Periodicals; Pollution -- Périodiques; Pollution -- Aspect de l'environnement -- Périodiques; Pollution -- Effets physiologiques -- Périodiques; Pollution; Pollution -- Environmental aspects; Periodicals; Electronic journals; 363.73
• DOI: 10.1016/j.envpol.2021.117825
• Languages: English
• ISSNs: 0269-7491

Abstract

Abstract: The feasibility and effectiveness of iron turning waste as low cost and sustainable permeable reactive barrier (PRB) media for remediating dieldrin, endrin, dichlorodiphenyltrichloroethane (DDT), and lindane individually (batch system) and combined (continuous flow column) in water were investigated. After 10 min of reaction in a batch system, removal of endrin, dieldrin, and DDT was higher (86–91 %) than lindane (41 %) using 1 g of iron turning waste in 200 mL of pesticide solution (20 μg/L for each pesticide). Among the studied pesticides, only lindane removal decreased substantially in the presence of nitrate (37 %) and magnesium (18 %). Acidic water environment (pH = 4) favored the pesticide removal than neutral and basic environments. For the column experiments, sand alone as PRB media was ineffective for remediating the pesticides in water. When only iron turning was used, the removal efficiencies of lindane, endrin, and dieldrin were 83–88 % and remained stable during 60 min of the experiments. DDT removal was less than other pesticides (58 %). Sandwiching the iron turning waste media between two sand layers improved DDT removal (79 %) as well as limited the iron content below a permissible level in product water. In a long-term PRB column performance evaluation, iron turning waste (150 g) removed all pesticides in water (initial concentration of each pesticide = 2 μg/L) effectively (≥94 %) at a hydraulic retention time of 1.6 h. Iron turning waste, which was mainly in the form of zerovalent iron (Fe 0 ), was oxidized to ferrous (Fe 2+ ) and ferric (Fe 3+ ) iron during its reaction with pesticides, and electrons donated by Fe 0 and Fe 2+ were responsible for complete dechlorination of all the pesticides. Therefore, it can be used as inexpensive and sustainable PRB media for groundwater remediation especially in developing countries where groundwater contamination with pesticides is more prevalent. Graphical abstract: Image 1 Highlights: Iron turning waste efficiently treated chlorinated pesticides in water. Iron turning waste completely dechlorinated all studied chlorinated pesticides. Except for lindane, pesticide removal was not affected by minerals in groundwater. Low water pH favored the removal of pesticides compared to neutral conditions. This study provides sustainable media for remediation of pesticides in groundwater. Abstract : Main finding : Iron turning waste has shown its ability as potential permeable reactive barrier media for remediating and completely degrading the organochlorine pesticides in water at a laboratory scale to meet the U.S. drinking water standards and/or World Health Organization health significance values. Iron turning waste is much more affordable than nano-zerovalent iron (nZVI), a similar material typically used for groundwater remediation. Iron turning waste can be used in developing countries that cannot afford nZVI for remediation of contaminants, especially organochlorine pesticides.