Removal of heavy metal ions from water using powdered rice husks and groundnut shell as adsorbents at Luwero industry limited

Abstract

In this project, the adsorption technique was employed for the removal of heavy metals such as lead and chromium in wastewater. These heavy metals arise from the production line processes such as chromo plating, alkaline washing and pickling using agricultural wastes such rice husks and ground nut shells as the adsorbent. These are used because of their excellent absorbability and are locally available in Uganda they are highly efficient in removal of heavy metals from waste water with a percentage removal ranging from 86%−100% for varying contact time, 40% - 65% for varying PH and 58% -79% for varying dosage. The main objective of this research was to investigate the removal efficiency of rice husks and ground nut shells powder as an adsorbent for lead and chromium in wastewater. The wastewater was obtained from the water stream leaving the chromo plating section by taking approximately about 3ppm concentrations of metal solutions and then treated against two adsorbents at varying pH, duration and adsorbent dosage using constant initial concentration of metals. From the findings the optimum pH for removal of heavy metals using powdered rice husks was between 5-7 and when using groundnuts as an adsorbent it was found to be between 6-7 while using a combination of rice husks and groundnuts shell as a mixture of adsorbent was found to be between PH of 5-6. The higher the contacting time of the adsorbent dose and the heavy metals from the waste water the higher the adsorption capacity of the adsorbent.