Delivering Arsenic-free Drinking Water-Made Practically Possible: Continuous Scale Electrochemical Arsenic Remediation Process Furnished, based on Experimental Studies and ANN Simulation

Abstract

Arsenic (As) in groundwater has become a worldwide concern due to its high toxicity as it is classified as a potent carcinogen, when exposed to drinking water. None of the reported As remediation technologies has so far been reasonably successful in overcoming the constraints encountered during on-field application. This paper evaluated the potential of modifying the well-acclaimed ElectroChemical Arsenic Remediation (ECAR) technique from ‘Batch Scale’ to a ‘Continuous Flow’ operation. The development of this innovative process modification involved a thorough investigation to understand the effects of different process parameters like, iron concentration, pH, dissolved oxygen (DO) and presence of co-occurring solute (PO43−). An indigenously fabricated 50 L continuous ECAR unit exhibited a successful remediation from 604 ppb of As(III) concentration to a value (% removal efficiency greater than 99%) less than the maximum contamination level prescribed by World Health Organization. Powder X-ray diffraction (PXRD) and scanning electron microscope (SEM) studies were conducted for iron-arsenic dry sludge to show a highly crystalline nature of the sludge, produced in the process. The experimental results were explored for the formulation of a feed-forward back-propagation artificial neural network (ANN) model to predict the removal efficiency of As from the contaminated water. The experimental outcome of the study justifies the feasibility and significance of the ‘continuous mode’ ECAR system in providing a tangible and sustainable solution towards global As contamination problem.