SORPTIVE REMOVAL OF CADMIUM BY SULFURIC ACID/ULTRASONIC-MODIFIED STRAW BIOCHAR FROM SIMULATED EUTROPHIC WATER.

Aiming at a dual purposes of resource conservation and environmental remediation, this study prepared com straw- and wheat straw-derived biochar and modified them by sulfuric acid and ultrasonic wave for the cadmium removal from artificially different eutrophic water. Results showed that the removal rates of cadmium on biochar were in the ranges of 73.5%-100% and 64.6%-100% from 0.3 and 10 mg/L of cadmium solution, respectively, which were both increased with the pH increasing. Under different conditions of TN and TP concentrations, the removal rates of the two concentrations of cadmium were 57.4%-100% and 40.1%-100%, respectively. With the increasing TN and TP concentrations, the variations of Cd on biochar altered differently in the low and high cadmium solutions. With the increasing eutrophication level, the removal rates of two concentrations of cadmium solution has a downward trend. The Cd removal rate highly depended on biochar types, environmental pH, TN and TP concentrations. Generally, the modified biochar had higher Cd removal rates than unmodified biochar. The modified wheat straw biochar performed the best in the cadmium removal from different eutrophic water with a maximal removal rate of 100%. The study provides an effective and environmental tool for heavy metals-contaminated eutrophic water body. [ABSTRACT FROM AUTHOR]