Developing a new controlled-release KMnO <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" id="d1e392" altimg="si4.svg"> <mml:msub> <mml:mrow/> <mml:mrow> <mml:mn>4</mml:mn> </mml:mrow> </mml:msub> </mml:math> for groundwater DNAPL remediation
Huali Chen, Jiqiang Lu, Li–guang Wu, Ting Wang, Zhengwen Liu, Cheng Wang, Kaixin Yan
Abstract
Controlled release material (CRM) is an emerging oxidant delivery technique for in-situ chemical oxidation (ISCO) to solve the problems of contaminants rebound, backflow and wake in groundwater remediation. In this paper, the potassium permanganate (KMnO4) was used as the main oxidant, paraffin as the carrier, and to enhance the permeability and adsorption quartz sand and activated carbon were added to make a new type CRM. By comparing the trichloroethylene (TCE) remediation efficiency, it was found that the optimal mass ratio of the CRM with KMnO4: paraffin: quartz sand: activated carbon is 2:10:10:2. Under the groundwater environment with lower temperature, lower pH, lower dissolved oxygen (DO), the new CRM provide longer release time. At the same time the higher the flow rate, the higher the permeability of the medium, the faster the release rate of the new CRM. The absorption of the medium may also influence the CRM release rhythm. The current work demonstrates the potential and better DNAPL remediation in groundwater of the new CRM.