Using Ionic Liquid Modified Zeolite as a Permeable Reactive Wall to Limit Arsenic Contamination of a Freshwater Lake—Pilot Tests

Abstract

Arsenic (As) contamination of surface water has long been a threat to human health. Extensive studies were made at the bench-scale for the removal of As from water. Commonly-used materials for the removal of As include Al and Fe hydroxides that will form complexes with As. Recently, modification of Earth materials to reverse their surface charge to positive to reduce the mobility of arsenite and arsenate also attracted great attention. In 2008, a severe As contamination was reported in the lake of Yangzonghai, Yunnan, China. Although the As concentration was maintained below 0.05 mg/L for the lake, after 28 months of restoration, the discharge of mine tailings from a nearby fertilizer plants was still one of the contributors to the As in the lake. In this study, zeolite was modified by ionic liquids and the modified materials were installed as a permeable reactive wall (PRW) to contain the As movement. Preliminary results showed more than an 80% reduction in As after surface water moved through the PWR over the six-month sampling period confirming the effectiveness of ionic liquid-modified Earth materials for environmental application.

Selective removal of arsenic in water: A critical review

“…The concept of permeable reactive walls or barriers exists mainly for the removal of dissolved contaminants in the water while ensuring regular water flow in either groundwater or surface water (Liao et al, 2018). A pilot study has been conducted in China to avoid/lower the As contamination of lake Yangzoghai (average 177 µg/L), Yunnan by surface runoff input sources (average 140 µg/L).…”

“…In May the As concentration at the upper stream of permeable reactive barrier was 0.14 mg/L and after passing through the permeable reactive barrier the As concentration was 0.004 mg/L with 96% removal. In August 2016 the As concentrations were 0.51 and 0.02 mg/L respectively with 96% removal (Liao et al, 2018). However, there is no data regarding selectivity behavior of the ionic liquid modified zeolite permeable reactive barrier.…”

Contaminación Del Agua Y Suelo Por Los Relaves Mineros

“…Se ha puesto en riesgo la biodiversidad, potencialmente por el U (Hudson et al, 2018). "Esgair Mwyn", una mina abandonada en la ciudad de Ceredigion, Reino Unido ha causado preocupación por la determinación de posibles infiltraciones de los relaves mineros en las aguas subterráneas y su impacto en la calidad del agua en la ciudad (Liao et al, 2018).…”