Citric Acid Wastewater As Drench Lotion On Soil Heavy Metal Cadmium Removal Research

Soil pollution by heavy metal has become one of the major growing soil problem in today’s world, how to remedy polluted soil reasonable has become a serious problem. Heavy metal polluted soil remediation has a very important significance to ecological environment and increase food production.In this thesis,for the study of heavy metal cadmium contaminated soil,using pretreated citric acid wastewater as eluent test soil samples for the desorption of heavy metal cadmium’s removal.Through a series of heavy metal adsorption/desorption batch experiments under different components and different reaction conditions wastewater removal efficiency of cadmium in the soil,which reveals synergistic citric acid wastewater removal mechanism of cadmium in soil.It can be observed from the results that the desorption of cadmium can reach 80% when the soil mixture pH is lower than 6. However,the proportion of desorbed cadmium decreases significantly with increase in soil mixture pH. The dominant cadmium desorption mechanism using CAIW is the complexion of cadmium with citric acid and acetic acid in CAIW,and mainly remove cadmium’s Exchangeable, Bound to Cnrbonates and Bound to Fe/Mn Oxides form.Among all forms rmoval of Exchangeable is the most significant. Based on the different concentration of citric acid wastewater and desorption experiment time,shows the relative concentration of citric acid wastewater,the desorption of the cadmium desorption efficiency is higher,and desorption of cadmium on soil particle surface by citric acid wastewater mainly happened in 10 hours. Through the analysis of the desorption experiments of citric acid and acetic acid, it can be obtained in acid soil, the desorption of the cadmium desorption efficiency is higher.