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, intra-particle 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.
Abad M, Noguera P, Puchades R, Maquieira A, Noguera V. 2002. Physico-chemical and chemical properties of some coconut coir dusts for use as a peat substitute for containerised ornamental plants. Bioresour Technol. 82(3):241–245. doi:10.1016/S0960-8524(01)00189-4.
Abdel Salam OE, Reiad NA, ElShafei MM. 2011. A study of the removal characteristics of heavy metals from wastewater by low-cost adsorbents. J Adv Res. 2(4):297–303. doi:10.1016/j.jare.2011.01.00.
Ahalya N, Ramachandra T, Kanamadi R. 2003. Biosorption of heavy metals. Res J Chem Environ. 7(4):71–79. http://wgbis.ces.iisc.ernet.in/energy/water/paper/biosorption/biosorption.htm.
Amarasinghe B. 2011. Lead and cadmium removal from aqueous medium using coir pith as adsorbent: batch and fixed bed column studies. J Trop For Environ. 1(1):36–47. doi:10.31357/jtfe.v1i1.82.
Aquino D, Tanchuling M, Fontanilla L. 2009. Effect of flow rates in the removal of lead ions from solution in a coco peat column. Proceedings of the 3rd Engineering Research and Development for Technology (ERDT) Conference; Mandaluyong City, Philippines. p. 82–85. http://koha.nlp.gov.ph/cgi-bin/koha/opac-ISBDdetail.pl?bib=766997.
Benavente M, Moreno L, Martinez J. 2011. Sorption of heavy metals from gold mining wastewater using chitosan. J Taiwan Inst Chem Eng. 42:976–988. doi:10.1016/j.jtice.2011.05.003.
Clescerl LS, Greenberg AE, Eaton AD, editors. 1998. Standard methods for the examination of water and wastewater. 20th edition. Maryland: American Public Health Association.
Conrad K, Bruun Hansen H. 2007. Sorption of zinc and lead on coir. Bioresour Technol. 98(1):89–97. doi:10.1016/j.biortech.2005.11.018.
Diola M, Orozco C. 2014. Improved removal of copper ions from aqueous solution using NaOH-pretreated cocopeat. ASEAN Eng J Part C. 4(1):93–103. http://seed-net.org/wp-content/uploads/2015/12/IMPROVED-REMOVAL-OF-COPPER-IONS-FROM-AQUEOUS-SOLUTION-USING-NaOH-PRETREATED-COCO-PEAT.pdf.
Einollahipeer F, Pakzadtoochaei S. 2013. Removing nickel and zinc from aqueous environments using modified cocopeat. Int Res J Appl Basic Sci. 4(11):3434–3443. http://www.irjabs.com/files_site/paperlist/r_1320_130916130016.pdf.
Hazeri N, Shakeri A, Vlizadeh J, Hashemi E, Motavalizadeh Kakhki A. 2012. Removal of lead (ii) from aqueous solution using cocopeat: an investigation on the isotherm and kinetic. Iran J Chem Chem Eng. 31(3):45–50. http://www.ijcce.ac.ir/article_5950_008bd3ee80396123299e9f929ecbc067.pdf.
Ho Y, Mckay G. 2000. The kinetics of sorption of divalent metal ions onto sphagnum moss peat. Wat Res. 34:735–742. doi:10.1016/S0043-1354(99)00232-8.
Israel DC, Asirot JP. 2002. Mercury pollution due to small-scale gold mining in the Philippines: an economic analysis. Research Paper Series No. 2002.02. Makati City: Philippine Institute for Development Studies. https://dirp4.pids.gov.ph/ris/rps/pidsrp0202.pdf.
Kaczala F, Marques M, Hogland W. 2009. Lead and vanadium removal from a real industrial wastewater by gravitational settling/sedimentation and sorption onto Pinus sylvestris sawdust. Bioresour Technol. 100:235–243. doi:10.1016/j.biortech.2008.05.055.
Kazemipour M, Ansari M, Tajrobehkar S, Majdzadeh M, HRK. 2008. Removal of lead, cadmium, zinc, and copper from industrial wastewater by carbon developed from walnut, hazelnut, almond, pistachio shell, and apricot stone. J Hazard Mater. 150(2):322–327. doi:10.1016/j.jhazmat.2007.04.118.
Lee B, Rowell R. 2004. Removal of heavy metal ions from aqueous solutions using lignocellulosic fibers. J Nat Fibers. 1(1):97–108. doi:10.1300/J395v01n01_07.
Oboh I, Aluyor E, Audu T. 2009. Biosorption of heavy metal ions from aqueous solutions using a biomaterial. Leonardo J Sci. 14:58–65. http://ljs.academicdirect.org/A14/058_065.pdf.
Ong D. 2010. Removal of heavy metals from single species and composite species aqueous solutions using coco peat as sorbent material [master’s thesis]. [Quezon City]: University of the Philippines Diliman. http://koha.nlp.gov.ph/cgi-bin/koha/opac-ISBDdetail.pl?bib=622583.
Parcon M. 2010. Equilibrium and kinetic studies on the adsorption of lead and copper in aqueous solution on coco peat [master’s thesis]. [Quezon City]: University of the Philippines Diliman. http://koha.nlp.gov.ph/cgi-bin/koha/opac-ISBDdetail.pl?bib=622583.
Perez E, Appel P, Koester-Rasmussen R. 2007. Training of small scale miners and their families in safe handling of mercury during extraction of gold in the Philippines. Improving access to social services: health services and income opportunities for small scale miners and their families. Copenhagen: Geological Survey of Denmark and Greenland, Ministry of the Environment. Danmarks Og Grønlands Geologiske Undersøgelse Rapport 2007/35. http://artisanalmining.org/Repository/01/The_CASM_Files/CASM_Meetings_International/2007_Ulaanbaatar_AGM/Presentations/5.3_Breakout_Environment_technology_%28incl._PreConf_session%29/Appel_Philippines_training_report.pdf.
Pingul S. 2010. Efficiency of coco peat in adsorbing Cd (II): evaluation using batch tests [master’s thesis]. [Quezon City]: University of the Philippines Diliman. http://koha.nlp.gov.ph/cgi-bin/koha/opac-ISBDdetail.pl?bib=622594.
Samaniego J, Tanchuling M. 2018. Sedimentation tests of small scale gold mining wastewater. Int J Sci Technol Res. 7(6):73–80. http://www.ijstr.org/final-print/june2018/Sedimentation-Tests-Of-Small-Scale-Gold-Mining-Wastewater-.pdf.
Velasquez-Lopez P, Veiga M, Hall K. 2010. Mercury balance in amalgamation in artisanal and small-scale gold mining: identifying strategies for reducing environmental pollution in portovelo-zaruma, ecuador. J Clean Prod. 18:226–232. doi:10.1016/j.jclepro.2009.10.010.
Vijayaraghavan K, Rangabhashiyam S, Ashokkumar T, Arockiaraj J. 2016. Mono- and multi-component biosorption of lead(ii), cadmium(ii), copper(ii) and nickel(ii) ions onto coco-peat biomass. Sep Sci Technol. 51(17):2725–2733. doi:10.1080/01496395.2016.1212889.
Waskita K, Resurreccion A, Budianta W. 2012. Kinetic and equilibrium studies on the adsorption of pb2+ and zn2+ from aqueous solution using coco-peat by batch experiment. J Appl Geol. 4(1):29–35. doi:10.22146/jag.7194.