Walnut Shell: An Effective Treatment for Cassava Wastewater

Abstract

Cassava wastewater, a byproduct of cassava processing, poses significant environmental challenges due to its high levels of organic compounds, cyanogenic glycosides, and other pollutants. This study focuses on investigating the feasibility of using walnut shell-based activated carbon as an eco-friendly and cost-effective adsorbent for removing contaminants from cassava effluents.Walnut shells were processed into activated carbon through activation and carbonization using orthophosphoric acid as the activating agent. The prepared activated carbon was then used in a column setup where the cassava wastewater was passed through the column to allow for the adsorption of contaminants. Heavy metals, COD, sulphates, nitrates, and pH analysis were carried out before and after treatment to assess the adsorbent's effectiveness. The results showed that the concentration of Cyanide reduced from 3.91 ± 0.10 mg/L to 1.91 ± 0.15 mg/L. Chromium reduced from 0.07 ± 0.01 mg/L to 0.03 ± 0.01 mg/L, Lead reduced from 11.25 ± 0.31 mg/L to 0.97 ± 0.06 mg/L, while cadmium and manganese were completely removed from the effluent. A slight change was observed in the COD level. Sulphate levels decreased from 677.00 ± 4.00 mg/L to 178.48 ± 0.54 mg/L, while nitrate concentrations dropped from 54.40 ± 0.40 mg/L to 21.27 ± 0.78 mg/L. The findings in this study affirmed that walnut shell-based activated carbon is an effective adsorbent for the treatment of cassava wastewater.