Emerging remediation potentiality of struvite developed from municipal wastewater for the treatment of acid mine drainage

Vhahangwele Masindi; Elvis Fosso-Kankeu; Ednah Mamakoa; Thabo T I Nkambule; Bhekie B Mamba; Mu Naushad; Sadanand Pandey

doi:10.1016/j.envres.2022.112944

Emerging remediation potentiality of struvite developed from municipal wastewater for the treatment of acid mine drainage

Environ Res. 2022 Jul:210:112944. doi: 10.1016/j.envres.2022.112944. Epub 2022 Feb 17.

Authors

Vhahangwele Masindi¹, Elvis Fosso-Kankeu², Ednah Mamakoa³, Thabo T I Nkambule⁴, Bhekie B Mamba⁴, Mu Naushad⁵, Sadanand Pandey⁶

Affiliations

¹ Magalies Water, Scientific Services, Research & Development Division, Erf 3475, Stoffberg Street, Brits, 0250, South Africa; Department of Environmental Sciences, College of Agriculture and Environmental Sciences, University of South Africa (UNISA), P. O. Box 392, Florida, 1710, South Africa.
² Institute for Nanotechnology and Water Sustainability (iNanoWS), College of Science Engineering and Technology (CSET), University of South Africa, Florida Science Campus, South Africa; Department of Mining Engineering, College of Science Engineering and Technology, University of South Africa, Florida Science Campus, South Africa; Water Pollution Monitoring and Remediation Initiatives Research Group, School of Chemical and Minerals Engineering, North West University, South Africa. Electronic address: elvisfosso.ef@gmail.com.
³ Magalies Water, Scientific Services, Research & Development Division, Erf 3475, Stoffberg Street, Brits, 0250, South Africa; Water Pollution Monitoring and Remediation Initiatives Research Group, School of Chemical and Minerals Engineering, North West University, South Africa.
⁴ Institute for Nanotechnology and Water Sustainability (iNanoWS), College of Science Engineering and Technology (CSET), University of South Africa, Florida Science Campus, South Africa.
⁵ Department of Chemistry, College of Science, King Saud University, P.O. Box 2455, Riyadh, 11451, Saudi Arabia.
⁶ Department of Chemistry, College of Natural Science, Yeungnam University, Gyeongsan, 38541, Republic of Korea. Electronic address: sadanand.au@gmail.com.

PMID: 35183518
DOI: 10.1016/j.envres.2022.112944

Abstract

The valorisation of wastewaters for minerals recovery and their potential beneficiation has gained enormous attention recently. In this study the removal of phosphate and ammonia from municipal wastewater using activated magnesite resulted in the formation of struvite. The optimum conditions for the synthesis of struvite were 60 min of mixing, 300 rpm mixing speed, 1 g of activated magnesite and room temperature, whilst optimum conditions for the treatment of acid mine drainage (AMD) using the synthesized struvite were 45 min of mixing, 20 g of struvite dosage, 1000 mL, and 300 rpm mixing speed. The efficacy of struvite for neutralisation of AMD and attenuation of inorganic contaminants were ≥98.99% for metals (Al³⁺, Fe³⁺, and Mn²⁺) and ≥30% for SO₄^2-. Traces of other metals such as Zn, Cu, Ni, Pb, and Cr were significantly attenuated. Phosphate was fully attenuated from the aqua-sphere. PHREEQC predicted the removal of minerals as oxy-(hydro)-sulphates, oxy-(hydro)-phosphate, metals hydroxides, and other complexes. FE-SEM equipped with FIB and an EDX, XRD, XRF, and FTIR confirmed the synthesis of struvite and fate of chemical species after treatment. This study confirmed the feasibility of recovering phosphate and ammonia as struvite which can be employed for the treatment of AMD.

Keywords: Acid mine drainage; Acid mine drainage treatment; And PHREEQC geochemical Model; Characterisation; Minerals recovery; Minerals synthesis; Real municipal wastewater; Struvite synthesis.

MeSH terms

Ammonia
Minerals
Phosphates
Struvite
Wastewater* / chemistry
Water Pollutants, Chemical* / analysis

Substances

Minerals
Phosphates
Waste Water
Water Pollutants, Chemical
Ammonia
Struvite