| dc.description.abstract | Rapid population growth and expansion of industries have led to an increase in the presence of heavy metals in wastewater. Irregular discharge of such wastewater with little or no treatment has been rampant in developing countries. Exposure to heavy metals has been associated with stunted growth and development, acute and chronic respiratory effects, cancerous effects, autoimmunity and even death. Technological solutions for heavy metal removal that are affordable, environmentally benign, and simple to use are needed to address these challenges. This study experimented the effectiveness of using two differently modified bamboo biochar in removal of selected heavy metals from wastewater stabilization ponds (WSPs) effluents in Embu town, Kenya. One modification involved pyrolysis hourly at 250°C, then at 350°C, and lastly at 500°C and labelled AC whereas the other involved chemical activation using potassium hydroxide followed by pyrolysis and referred as AC+KOH. Characterization of AC resulted to 3%, 82%, 62mg/g, 13.5% and 11.9% in moisture, volatile matter, iodine number, ash content and carbon yield whereas AC+KOH had 7%, 91.5%, 259mg/g, 11% and 13.4% respectively. Sampling of wastewater effluents along the treatment processes, seven designated points was conducted during the wet and dry season, totalling to forty-two samples. Atomic absorption spectrophotometer was used to analyse the amounts of Cu2+, Cd2+ and Pb2+ ions. Levels of Cu2+, Cd2+ and Pb2+ ions ranged from 0 to 0.097 ppm, 0.004 ppm and 0.355 ppm respectively. SPSS version 26 was used for statistical analysis. Upon treatment of polluted effluents using AC, there was significant removal of Pb2+ ions ranging from 86% to 100%, whereas treatments using AC+KOH ranged between 72% to 90%. Findings from the study indicates effectiveness of bamboo biochar in treating wastewater contaminated with Pb2+ with AC performing better than AC+KOH. Adoption of these green strategies would provide a cheap and eco-friendly alternative to conventional approaches. | en_US |
