REMOVAL OF HEAVY METALS BY USING LOW COST ADSORBENTS

Abstract

The metals content in wastewater was affected by human activities and natural sources. The study is designed to study the removal of heavy metals by low cost adsorbents. The adsorbents select are from agriculture waste which were curcurbita skin and perkia speciosa pod. The wastes were collected from residential areas. Both curcurbita skin and perkia speciosa pod waste transformed into powder form with the particles range from 300µm to 400µm size particles. The samples were tested by several manipulated variables such as difference amount of dosages, concentration solutions and different speed at. The synthetic wastewater solutions were prepared which were zinc, copper and lead solutions and the pH were adjusted to optimum pH at 5.5. These samples were analyzed by using Atomic Absorption Spectrophotometer (AAS). According to the results, both adsorbents had ability to remove the heavy metals. The higher dosage which at 0.5g gave higher tendency to remove the metals. For examples, at speed 300rpm, the 0.5g of curcurbita skin can remove 97.04%, while for perkia speciosa pod about 86.85%. While at high speed at 1000 rpm, curcurbita skin, remove 99.63%, while perkia speciosa pod removed 99.83%. The higher speed of agitation at 1000 rpm also give a high percentage of metals removal. For examples, at 0.05g of curcurbita skin, about 99.71% removed, while perkia speciosa pod 99.6% removed. While for 0.5g dosages, curcurbita skin remove 99.63%, while perkia speciosa pod removed 99.83%. Meanwhile the concentration solutions at 1 ppm give higher removal from the range of 98.92% to 99.22% for perkia speciosa pod and curcurbita skin because the amount of metals inside that concentration had small amount. Therefore, perkia speciosa pod was showing it potential to remove the metals, whether in small or big amount of dosage, high and low concentration and also at high and slow speed better than curcurbita skin. But for the curcurbita skin, it can remove better in high speed and high dosage of adsorbents. So by comparing these adsorbents, perkia speciosa pod was chosen as the best adsorbent in this project.