Efficient artificial mineralization route to decontaminate Arsenic(III) polluted water -the Tooeleite Way

TL;DR

This paper presents a novel, efficient artificial mineralization method inspired by natural Tooeleite formation to remove toxic As(III) from contaminated water at neutral pH, addressing a critical gap in arsenic remediation technology.

Contribution

It introduces a new nanoscale mineralization approach using ZnS nanorods as nucleation centers to immobilize arsenic in water, mimicking natural mineralization processes.

Findings

Successfully grew Tooeleite-like structures at neutral pH

Achieved effective arsenic removal from contaminated water

Demonstrated potential for scalable water treatment applications

Abstract

Increasing exposure to arsenic (As) contaminated ground water is a great threat to humanity. Suitable technology for As immobilization and removal from water, especially for As(III) than As(V), is not available yet. However, it is known that As(III) is more toxic than As(V) and most groundwater aquifers, particularly the Gangetic basin in India, is alarmingly contaminated with it. In search of a viable solution here, we took a cue from the natural mineralization of Tooeleite, a mineral containing Fe(III) and As(III)ions, grown under acidic condition, in presence of SO42- ions. Complying to this natural process, we could grow and separate Tooeleite-like templates from Fe(III) and As(III) containing water at overall circumneutral pH and in absence of SO42- ions by using highly polar Zn-only ends of wurtzite ZnS nanorods as insoluble nano-acidic-surfaces. The central idea here is to exploit these insoluble nano-acidic-surfaces (called as INAS in the manuscript) as nucleation centres for Tooeleite growth while keeping the overall pH of the aqueous media neutral. Therefore, we propose a novel method of artificial mineralization of As(III) by mimicking a natural process at nanoscale.