A membrane-based green and low-cost system for ensuring safe drinking water in a selenium-affected region.
JOURNAL OF ENVIRONMENTAL MANAGEMENT 2022;
324:116361. [PMID:
36198222 DOI:
10.1016/j.jenvman.2022.116361]
[Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/16/2022] [Revised: 09/17/2022] [Accepted: 09/22/2022] [Indexed: 06/16/2023]
Abstract
Towards an efficient, low-cost solution to the problem of contamination of groundwater by selenium leached out from earth's mineral crust, a new system is developed using a novel graphene-based nanocomposite membrane. The system not only purified selenium-contaminated groundwater with high degree but also ensured safe disposal of the rejected selenium through algorithmic chemical stabilization in a mineral matrix. All experiments were conducted with live contaminated water from selenium affected area rather than using synthetic solution in a semi-pilot unit involving a largely fouling-free flat sheet cross-flow membrane module. Pure water flux of up to 190 Lm-2h-1(LMH) with 96-97% selenium rejection at an optimum operating pressure of only 14 bar could be achieved. Rejected selenium was stabilized in mineral matrix through chemical coagulation-precipitation using suitable coagulants following prior optimization of the critical operating parameters by Model-based calibration toolbox (MATLAB R2020a). A high degree of stabilization efficiency (99.8%) could be achieved as reflected in an error-index of only 1.13%. For selenium-affected region, the membrane-integrated hybrid treatment system proved to be a potential candidate technology offering safe drinking water at an approximate cost of only 1.77 $/m3 which was found to be affordable to the consumers in subsequent willingness to pay survey.
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