Reusing sludge from surface water treatment plant for hexavalent chromium adsorption in aqueous solution

Contaminants in plating wastewater are hard to remove, especially hexavalent chromium ions. This waste stream contains a large amount of Cr6+, highly toxic metal, potential cause cancer. To reduce this pollution, sludge from supply water treatment plant (DWTS) has been used make adsorbent. was denaturized by thermal method. After that, synthetic contained Cr6+ treated batch adsorption model with adsorbent made DWTS. pH, adsorbent, and time were investigated determine the suitable conditions. The study also evaluated suitability two models Langmuir Freundlich. Results showed under conditions pH = 6.0, content 25.0 g/l, after 90.0 minutes, remained 0.14 mg/l, close QCVN 40:2011/BTNMT, column B. parameters Freundlich equations are: qmax 12.578 mg/g; Kads 0.747 l/mg; n 0.338; kf 5.138. isothermal is better fitted process than model.