Removal of Heavy Metals from an Actual Small Scale Gold Mining Wastewater by Sorption onto Cocopeat

Abstract

Cocopeat, a by-product of coconut husk, was used as adsorbent material to remove mercury (Hg) and other heavy metals (As, Ba, Cd, Pb) from the wastewater gathered from the tailings collection tank of a ball mill facility at the small scale gold mining (SSGM) area in Camarines Norte province, Philippines. Batch sorption tests were carried out using actual wastewater samples with reduced suspended solids collected after 60 min of settling and without modifying the pH and other parameters to simulate the actual condition in the field. Batch tests of water samples with an initial pH of 7.30 and adsorbent dose of 1.0 g cocopeat/L were tested for Lagergren first-order, pseudo-second-order, intraparticle diffusion, and Freundlich models to evaluate kinetic parameters and adsorption isotherms. The removal efficiencies obtained for the heavy metals after the equilibrium time of 240 min were 97.14%, 94.74%, 10.00%, 66.67%, and 27.01% for Hg, As, Ba, Cd, and Pb, respectively. The pseudo-second order kinetics model represented well the adsorption process as demonstrated with its higher correlation coefficients among the models.

Mining wastewater treatment technologies and resource recovery techniques: A review

“…Samaniego and Tanchuling [ 72 ] reported the treatment of heavy metal-laden wastewater collected from a small-scale gold mining site in Paracale, Camarines Norte, Philippines, using a sedimentation tank (primary treatment) and a Cocopeat (coconut husk by-product) filter bed as an adsorbent ( Fig. 9 ).…”

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Fig. 9 Schematic of filter bed system installed in a small-scale gold mining processing plant [ 72 ].

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A Sustainable Approach for Removing Organic Pollutants from Food Processing Effluents Using Unmodified Cocopeat as an Adsorbent

“…According to a morphological study by Lee et al (2018), the surface structure of the cocopeat surface revealed that the number of large pores reduced with increasing contact time and increased the fraction of smaller pores, indicating the attachment of substances within the cocopeat macropores (Verasoundarapandian et al, 2021). Furthermore, the efficiency of cocopeat as an adsorbent material has been demonstrated in treating various contaminants from various types of water, including multiple types of heavy metals (Atikah et al, 2017;Samaniego & Tanchuling, 2019;Shakeri et al, 2012).…”