Binary and ternary metals adsorption from greywater using spent green tea as a novel adsorbent

Raphael B.H. Gameli; Elliot H. Alhassan; Abudu B. Duwiejuah; Emmanuel D. Abarike; Abdul-Aziz Bawa

doi:10.17159/sajs.2023/13352

Authors

Raphael B.H. Gameli Department of Environment and Sustainability Sciences, Faculty of Natural Resources and Environment, University for Development Studies, Nyankpala Campus, Tamale, Ghana https://orcid.org/0000-0002-0721-7996
Elliot H. Alhassan Department of Fisheries and Aquatic Resources Management, Faculty of Biosciences, University for Development Studies, Nyankpala Campus, Nyankpala, Ghana https://orcid.org/0000-0002-9029-9522
Abudu B. Duwiejuah Department of Biotechnology and Molecular Biology, Faculty of Biosciences, University for Development Studies, Nyankpala Campus, Tamale, Ghana https://orcid.org/0000-0002-9033-0526
Emmanuel D. Abarike Department of Fisheries and Aquatic Resources Management, Faculty of Biosciences, University for Development Studies, Nyankpala Campus, Tamale, Ghana https://orcid.org/0000-0003-4873-6546
Abdul-Aziz Bawa Spanish Laboratory Complex, University for Development Studies, Nyankpala Campus,Tamale, Ghana https://orcid.org/0000-0003-4455-450X

DOI:

https://doi.org/10.17159/sajs.2023/13352

Keywords:

adsorption, binary system, greywater, mercury, green tea

Abstract

Adsorption is one of the most easy-to-operate, less costly, efficient and, most importantly, environmentally friendly methods of removing toxic metals from aqueous environments. We used spent Impra Green Tea Ginseng Flavoured to recover mercury (Hg²⁺), lead (Pb²⁺) and cadmium (Cd²⁺) in binary and ternary systems from greywater. We undertook this study in binary and ternary systems at adsorbent dosages with a corresponding 100 mL varied initial metal concentrations of the greywater. The adsorption efficiency at varied concentrations and dosages in the binary systems by the spent tea waste ranged from 38.5% to 100% for lead, 11.50% to 100% for cadmium and was 100% for mercury. In the ternary system, the adsorption efficiency of toxic metals ranged from 28.91% to 72.85% for cadmium and was 100% for mercury and lead. The maximum adsorption capacity (Q_e) for toxic metals in the binary system ranged from 38.46 to 81.97 mg/g for Pb²⁺ and 12.64 to 56.82 mg/g for Cd²⁺. The Langmuir adsorption isotherm model was the best fit for the adsorption of toxic metals by Impra Green Tea Ginseng Flavoured. The pH under which the experiments were conducted showed very high removal efficiency for lead and mercury but lower removal efficiencies for cadmium. Spent Impra Green Tea Ginseng Flavoured can be used as an effective and low-cost adsorbent of toxic metals from greywater or wastewater. Based on our findings, further studies should be conducted to determine the effects of varying the contact time, temperature and elevated metal concentrations in the greywater or other wastewater.

Significance:

This study provides useful information on how spent Impra Green Tea Ginseng Flavoured can be used as an effective and low-cost adsorbent of toxic metals from greywater or wastewater.