Preparation Of Low-Cost Biochar For Water Treatment Based On Water Quality In South Sudan

Water contamination is becoming a serious scenario today,which is due to industrial development,uses of fertilizers and population increase.This had influenced the provisions of clean water to many people around the world.In South Sudan,over 50%of the population lack clean water.Waterborne diseases are common among the communities and the effect of crude oil industrialization has led to increasing chemical contaminations of both surface and underground water in the northeastern part of the country which has caused more health issues and dead especially to children.Cattle rearing and small-scale agriculture are common activities among South Sudanese but their byproduct has not been put into use yet.In this study,biochar was prepared from two common different biomasses found in South Sudan,cow dung and corncob.The biochar preparation was done at different pyrolysis temperature.With higher pyrolysis temperature,the product yield reduced while the ash content and surface p H value increased.The product yield,ash content,p H value of cow dung derived biochar was higher than the one of corncob derived biochar.The characteristics of the biochar were determined by using a scanning electron microscope to analyze their surface morphology which revealed the honeycomb on the surface of the corncob and the smooth surface of the cow dung biochar.FT-IR spectroscopy was used for surface functional groups determination in which it reveals that as the temperature increases the surface functional groups decreases,BET was used to analyze the surface area and porosity,which showed that higher temperature leads to the higher surface area.Biochar prepared under higher temperature often showed higher capacity on the adsorption of CODs,NH₃-N and Pb（II）,the larger surface area,higher content of exchangeable cations provided by the ash and the higher p H value were considered the main reason.For methylene blue,cow dung biochar prepared under lower temperature performed better for its richer surficial functional groups,which confirmed that higher surface area was not the only requirement of adsorbents.The adoption capacity of CDB600 to Pb（II）was 217.4 mg/g and the adsorption fitted the Langmuir model and pseudo-second-order kinetic,which confirmed the leading role of chemisorption on the mechanism.However,all origin biochar showed poor adsorption capacity on Ba（II）.The biochar was modified by the impregnation method.For Pb（II）adsorption,Mg O modified cow dung biochar showed a remarkable adsorption capacity,which fitted the Langmuir model with maximum adsorption capacity up to 833.3 mg/g and the pseudo-second-order kinetic model.For barium adsorption,Na OH modified biochar showed the best performance among the adsorbent modified by series chemical contained Na OH,Na₂SO₄,Fe₂（SO₄）₃ and H₂SO₄,and the adsorption capacity was 97 mg/g.While ion exchange and precipitation were the main mechanism of Pb（II）adsorption by CD-Mg O,surficial functional groups played a major role in the Ba（II）adsorption by CD-Na OH.Desorption capacities and reusability for each biochar were remarkable and the column studies have shown an adoption capacity of 170 mg/L.The origin and the modified biochar prepared in this study can be used as a promising solution for water treatment in South Sudan...