Study On The Effect Of Biochar And Organic Amendment For Immobilization Of Heavy Metals

Heavy metal pollution of soil or water has become a severe problem around the globe.Among all toxic pollutants,cadmium?Cd?have the eccentric deleterious effects on plant growth and human health that results in 7%of pollution in soil.Soil amendment has been proposed as a promising way to ameliorate soil properties to cope with toxic metals.Biochar as the immobilizing agent has got much attention due to its multifaceted and physiochemical properties obtained by high temperature or limited supply of oxygen that may provide large surface area and functional groups for remediation of contaminated soil.This study provides an overview on,the new perspective and contrast impact of biochar?wheat and rice straw biochar?and attapulgite clay in terms of adsorption and removal of cadmium(Cd²⁺)ions in aqueous solution using batch adsorption experiments.The paramount parameters influencing the adsorption capacity solely depends on the pH,initial metal concentration,adsorbent dose and contact time were identified.The Cd²⁺loaded adsorbent samples were tested on SEM,FTIR,XRD,and others.The wheat straw biochar?WSB?immobilization effect on Cd²⁺and Pb was additionally reviewed in the soil.The following results were obtained:1.The results shown that;WSB is exhibiting porous structure,high surface area?4.58 m²/g?,pore volume?0.0071 cm²/g?,contain high carbon content and moderate oxygen functional groups,respectively.The linear Langmuir adsorption isotherm and Pseudo-second-order kinetics models could be the best fit with the current study;and indicators showed the maximum removal at pH 6 with 0.1 g dose of adsorbents,the initial metal concentration of 40 mg/l,and at the range of 100 to 160 min at 30°C.Furthermore,the maximum removal efficiency was achieved to 95%by WSB.The reasons for the high adsorption rate and removal of Cd²⁺content onto the surface of adsorbent was mainly attributed due to the presence of surface carboxyl functional groups and surface complexation with cation exchange reactions.2.Based on the pre-experiment,the wheat pot experiment was conducted under eight different combinations of biochar and compost to evaluate their effect on soil properties,wheat physiological growth,and heavy metals remediation in the soil.At the same time,compost of sheep manure and crops straw with microbial inoculation was prepared for soil amendment.The impact of amendments had increased the pH?8%?,soil porosity?22%?,urease and alkaline phosphatase,28%and 10%respectively,NH₄OH₃ and nitrate.The compost?COM?catalase activity were decreased without biochar addition,while urease and alkaline phosphatase activity were significantly improved with biochar and compost amendments.3.The soil and wheat acid digested samples were analyzed by atomic absorption spectroscopy.The BC5 has shown high Cd²⁺immobilization effects in all treatments.These results indicated that BC5 have significantly reduced the Cd²⁺and Pb accumulation in wheat roots and shoots by 60%and 40%,respectively.However,the compost has a neutral role on remediation of Cd²⁺and Pb in the soil.Compared with the control,the biomass of wheat root and bud increased by 37%and 77%respectively,and the plant height increased by 42%under the treatment of biochar and compost?BC1?.In conclusion,these results explored the scientific and efficient techniques for adsorption and remediation of heavy metals.Interaction of biochar and compost have influences on each other properties.WSB and compost represent a promising candidate to remediate Cd²⁺and Pb in water or soil and provide a combination as soil ameliorant.Hence,our results provide a basic beneficial combination is recommending for the remediation of toxic metals in water,soil,and other cereals crops.