Ineffectiveness and Poor Reliability of Arsenic Removal Plants in West Bengal, India

Abstract

In the recent past, arsenic contamination in groundwater has emerged as an epidemic in different Asian countries, such as Bangladesh, India, and China. Arsenic removal plants (ARP) are one possible option to provide arsenic-safe drinking water. This paper evaluates the efficiency of ARP projects in removing arsenic and iron from raw groundwater, on the basis of our 2-year-long study covering 18 ARPs from 11 manufacturers, both from home and abroad, installed in an arsenic affected area of West Bengal, India, known as the Technology Park Project (TP project). Immediately after installation of ARPs on August 29, 2001, the villagers began using filtered water for drinking and cooking, even though our first analysis on September 13, 2001 found that 10 of 13 ARPs failed to remove arsenic below the WHO provisional guideline value (10 microg/L), while six plants could not achieve the Indian Standard value (50 microg/L). The highest concentration of arsenic in filtered water was observed to be 364 microg/L. Our 2-year study showed that none of the ARPs could maintain arsenic in filtered water below the WHO provisional guideline value and only two could meet the Indian standard value (50 microg/L) throughout. Standard statistical techniques showed that ARPs from the same manufacturers were not equally efficient. Efficiency of the ARPs was evaluated on the basis of point and interval estimates of the proportion of failure. During the study period almost all the ARPs have undergone minor or major modifications to improve their performance, and after our study, 15 (78%) out of 18 ARPs were no longer in use. In this study, we also analyzed urine samples from villagers in the TP project area and found that 82% of the samples contained arsenic above the normal limit.

The effect of nanocrystalline magnetite size on arsenic removal

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“…Desorption studies were conducted only with the 20 and 300 nm Fe 3 O 4 at pH 6.1, by adding As-free electrolyte to the As-exposed Fe 3 …”

“…Several methods of As removal are already available including precipitation, adsorption, ion exchange, solvent extraction, nanofiltration, foam flotation, and biological sequestration [2]. However, as recently noted these technologies cannot perform well in actual field trials, and improved materials and systems are needed [3]. In particular, sorbents must be able to achieve a low As level in drinking water for geographical areas with high As concentrations.…”

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“…Arsenic in groundwater is a widespread contaminant in South East Asia affecting the quality of drinking water in Bangladesh, India [6] and Cambodia [7] and is also present to a lesser degree in the USA [8] and in parts of the UK. In Bangladesh, where the contamination is most acute, tube-wells were dug to access shallow aquifers with the aim of providing a microbial-free source of drinking water.…”

Are interventions to reduce the impact of arsenic contamination of groundwater on human health in developing countries effective?: a systematic review protocol

“…While correctly-maintained arsenic removal plants (ARPs) reduce levels of arsenic to safe values, an extensive programme to connect ARPs to tubewells in Bangladesh has resulted in many ARPs remaining unused or being actively rejected by communities [6,7].…”