Different Formula of Mixed Bacteria as a Bio-Treatment for Sewage Wastewater

Abstract

The ability and effectiveness of rice straw as a natural adsorbent, to remove Iron (Fe III), manganese (Mn II), zinc (Zn II) and lead (Pb II) ions from sewage water were investigated. Removal of heavy metals from sewage water is among the most important issues for many industrial countries. Removal of iron, manganese, zinc and lead from sewage water was carried out using rice straw (rs-raw), activated carbon prepared from rice straw (rs-AC1) and activated carbon prepared from chemically treated rice straw (rs-AC2 and rs-AC3). The effect of pH on adsorption of iron, manganese, zinc and lead ions and contact duration with the adsorbents were evaluated. The maximum adsorption values of Iron, manganese, zinc and lead ions were recorded at pH 7, 7.5, 5 and 5.5 respectively. The times required for maximum adsorption of iron, manganese, zinc and lead were found to be 30, 30, 30 and 60 mins. respectively, in case of using activated carbon prepared from chemically treated rice straw rs-AC2 and rs-AC3 for Iron, manganese, zinc and lead, respectively. The adsorption percentages were found to be 83%, 77%, 88% and 80% for iron, manganese, zinc and lead ions, respectively. The chemically treated adsorbents were found to be the most efficient adsorbents in heavy metal removal.