GeoPro Talks – Arsenic in Groundwater: Impact on Agro-ecosystem and Low-cost Removal Option in the Perspective of Bangladesh

November 10th, 2022 by

Arsenic(As), ranked as the 20th most naturally abundant element within the earth’s crust, is highly toxic in its inorganic form. Contamination of groundwater with elevated levels of geogenic As has been reported worldwide, even in developed countries like USA and Canada. In fact, As contaminated groundwater is considered as one of the major environmental disaster and health hazard due to its excessive use as a drinking water source. Moreover, the agro–ecosystem is also threatened because of the prolonged use of As contaminated groundwater for irrigation purposes, especially in the South and South–East Asia regions. This practice results in increased As concentration in agricultural top–soils, uptake by crops and plants, accumulation in plants and/or translocation to edible parts, and increased human exposure risks through the food chain. Rice is one of the noteworthy food items in which As tends to accumulate in higher concentrations. Yet, many South Asian countriessolely depend on As contaminated groundwater for irrigation of rice fields. Even though numerous studies have been conducted on arsenic removal from groundwater, limited works have focused on As removal from flowing irrigation water across the soil system. The major challenges in this respect are–treating high volume of irrigation water required for rice production and associated technological costs. The objective of the present study is to assessa low–costremoval method of Arseniteand Arsenate by “iron–oxide–coated jutefabric” through laboratory batch experiments. Locally available jute fabric has been used in the context of Bangladesh,which is one of the most critically affected countries by high levels of As contamination in groundwater (< 0.5 to > 4600 μg/L). Two different types of jute fabrics have been coated with iron oxide following two different coating methods and two drying methods, and subsequently assessed for their effectiveness in removing arsenic from groundwater in batch experiment. Results suggest that iron-coated jute fabrics have significant capacity to remove both As (III) and As(V) from groundwater, and could be used in amending irrigation channels for more efficient removal of As within the channel, ultimately reducing As loading to rice fields. This presentation also covers follow-up work on implementation of this method in an experimental setup under flowing water condition.

BIO:

Samia Syeoti Ramimis a PHD student in the Geo-environmental research group of the Civil Engineering Department of The University of British Columbia (UBC). She has obtained her BSc. and MSc. degrees in Civil Engineering from Bangladesh University of Engineering and Technology (BUET), in her home country Bangladesh. She has a research background on addressing contaminants in the groundwater and sediment-water system. Her current research focuses on understanding and integrating the fundamental processes governing the fate and transport of emerging contaminants in the sub-surface environment.

November 2022