This paper investigates the treatment of chromium （Cr） contaminated industrial sludge from a tanning process with ultrasound to enhance the sludge settling ability and dewatering ability. Ultrasound at various frequ...This paper investigates the treatment of chromium （Cr） contaminated industrial sludge from a tanning process with ultrasound to enhance the sludge settling ability and dewatering ability. Ultrasound at various frequencies, intensities, and time was tested to optimize the operation. The results show that treatment with 30 kHz, 12 W/L ultrasound for 120 s shortened the sludge settling time from 3 h to 1 h and reduced the supernatant Cr concentration. The ultrasonic treatment also reduced the sludge volume from 4.02 mL/g to 2.58 mL/g and increased the sludge Cr concentration by 2/3. The treated sludge could then be reused in the tanning operation. Proper ultrasonic treatment can significantly reduce the sludge volume and enhance the Cr reuse.展开更多
This study systematically evaluates the recovery of rare earth elements（REEs） from aqueous solution and industrial wastewater using magnetic nanoparticles CuFe2O4. The industrially manufactured CuFe2O4 displays a no...This study systematically evaluates the recovery of rare earth elements（REEs） from aqueous solution and industrial wastewater using magnetic nanoparticles CuFe2O4. The industrially manufactured CuFe2O4 displays a nonlinear isotherm for REEs adsorption, suggesting limiting binding sites on the CuFe2O4 surface. The recovery of REEs increases significantly from 0.1% to 99.99% with increasing pH（2.29-8.15）. At room temperature, the maxima recovery rates of Nd, La, and Ce are observed to be in a high capacity of 51.02, 42.02, and 40.16 mg/g, respectively. No significant attenuation of REE adsorption is observed with increasing NaCl concentration from 0.001 to 1.0 mol/L, showing high selectivity of REEs even in such high NaCl concentration matrix. In addition, desorption efficiency increases with the increasing concentration of HNO3 in the range of 0.005-0.05 mol/L. When HNO3 concentration is over 0.05 mol/L, the desorption efficiency can reach almost 100% in each batch experiment. Importantly, our results show that REEs can be sorbed and recycled from liquid crystal display（LCD） polishing wastewater, suggesting that CuFe2O4 may be a good candidate in the efficient and rapid recovery of REEs from industrial wastewater.展开更多
文摘This paper investigates the treatment of chromium （Cr） contaminated industrial sludge from a tanning process with ultrasound to enhance the sludge settling ability and dewatering ability. Ultrasound at various frequencies, intensities, and time was tested to optimize the operation. The results show that treatment with 30 kHz, 12 W/L ultrasound for 120 s shortened the sludge settling time from 3 h to 1 h and reduced the supernatant Cr concentration. The ultrasonic treatment also reduced the sludge volume from 4.02 mL/g to 2.58 mL/g and increased the sludge Cr concentration by 2/3. The treated sludge could then be reused in the tanning operation. Proper ultrasonic treatment can significantly reduce the sludge volume and enhance the Cr reuse.
基金Project supported by Shanghai Natural Science Foundation(17ZR1420700)State Key Laboratory of Pollution Control and Resource Reuse Foundation(PCRRF16013)Shanghai Gaofeng & Gaoyuan Project for University Academic Program Development
文摘This study systematically evaluates the recovery of rare earth elements（REEs） from aqueous solution and industrial wastewater using magnetic nanoparticles CuFe2O4. The industrially manufactured CuFe2O4 displays a nonlinear isotherm for REEs adsorption, suggesting limiting binding sites on the CuFe2O4 surface. The recovery of REEs increases significantly from 0.1% to 99.99% with increasing pH（2.29-8.15）. At room temperature, the maxima recovery rates of Nd, La, and Ce are observed to be in a high capacity of 51.02, 42.02, and 40.16 mg/g, respectively. No significant attenuation of REE adsorption is observed with increasing NaCl concentration from 0.001 to 1.0 mol/L, showing high selectivity of REEs even in such high NaCl concentration matrix. In addition, desorption efficiency increases with the increasing concentration of HNO3 in the range of 0.005-0.05 mol/L. When HNO3 concentration is over 0.05 mol/L, the desorption efficiency can reach almost 100% in each batch experiment. Importantly, our results show that REEs can be sorbed and recycled from liquid crystal display（LCD） polishing wastewater, suggesting that CuFe2O4 may be a good candidate in the efficient and rapid recovery of REEs from industrial wastewater.
