Samaniego, J. and M.A.N. Tanchuling.
Global Journal of Environmental Science and Management 5(4):461-470(2019)

A field-scale filter bed system was constructed and run for 50 days to treat heavy metal-laden wastewater from a small-scale gold mining site in the Philippines. The system consists of a sedimentation tank and filter bed with Cocopeat, a byproduct of coconut husk, as the adsorbent. Physicochemical parameters and heavy metal concentrations were monitored during the experiment, which was run at a flow rate of 40 L/hr for 3 hours daily wastewater application. A significant reduction was achieved on As (97.11%), Ba (39.75%), Cd (74.24%), Hg (97.02%), Pb (98.82%) in the sedimentation phase. Further reductions on As (1.39%), Ba (28.00%), Cd (4.95%), Hg (2.91%), Pb (0.97%) were achieved by adsorption in the Cocopeat filter bed. The physicochemical parameters and heavy metal concentrations of the effluent were within the respective regulatory limits. Effluent parameters with a strong correlation to total suspended solids, such as turbidity and color, were reduced significantly. All adsorbed heavy metals accumulated in the upper 25 cm of the Cocopeat column in the filter bed. Heavy metal concentrations in Cocopeat suggest that the adsorbent was not saturated, and further application of small-scale gold mining wastewater is recommended to determine its useful life. https://www.gjesm.net/article_36261_54175f505dfa7e82f9f8cf43a30f282f.pdf