title: Enhanced adsorption of chromium onto activated carbon by microwave-assisted H(3)PO(4) mixed with Fe/Al/Mn activation.
abstract: FeCl3, AlCl3 and MnCl2 were used as the assisted activation agent in activated carbon preparation by H3PO4 activation using microwave heating method. The physico-chemical properties of activated carbons were investigated by scanning electron microscope (SEM), N2 adsorption/desorption, Boehm's titration, X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS). To investigate the adsorption performances of chromium onto these newly developed activated carbons, a batch of experiments were performed under different adsorption conditions: solution pH, initial Cr(VI) ion concentration, contact time and co-existing ions. The results suggested that carbon with MnCl2 as assisted activation agent displayed the highest BET surface area (1332m(2)/g) and the highest pore volume (1.060cm(3)/g). FeCl3, AlCl3 and MnCl2 had successfully improved Cr(VI) adsorption and activated carbon with FeCl3 as assisted activation agent exhibited the best uptake capacity. To study the transformation of Cr(VI) in adsorption process, total chromium in the aqueous solution was also recorded. The ratio of the amount of Cr(VI) to Cr(III) on each adsorbent was explained by XPS analysis results. Both the co-existing salts (Na2SO4 and NaNO3) demonstrated promoted effects on Cr(VI) removal by four carbons. The pseudo-second-order model and Freundlich equation displayed a good correlation with adsorption data.
authors.affiliation: Shandong Provincial Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, Jinan 250100, PR China.
authors.forename: Yuanyuan
authors.initials: Y
authors.lastname: Sun
authors.affiliation: Shandong Provincial Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, Jinan 250100, PR China. Electronic address: qyyue58@aliyun.com.
authors.forename: Qinyan
authors.initials: Q
authors.lastname: Yue
authors.affiliation: School of Energy and Power Engineering, Shandong University, Jinan 250100, PR China.
authors.forename: Yanpeng
authors.initials: Y
authors.lastname: Mao
authors.affiliation: Shandong Provincial Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, Jinan 250100, PR China.
authors.forename: Baoyu
authors.initials: B
authors.lastname: Gao
authors.affiliation: Shandong Provincial Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, Jinan 250100, PR China.
authors.forename: Yuan
authors.initials: Y
authors.lastname: Gao
authors.affiliation: Shandong Provincial Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, Jinan 250100, PR China.
authors.forename: Lihui
authors.initials: L
authors.lastname: Huang
mesh_terms: D000327:Adsorption; D000535:Aluminum / Q000737:chemistry*; D002244:Carbon / Q000737:chemistry*; D002857:Chromium / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D007501:Iron / Q000737:chemistry*; D008345:Manganese / Q000737:chemistry*; D008872:Microwaves; D010756:Phosphoric Acids / Q000737:chemistry; D016062:Porosity; D013499:Surface Properties; D014865:Waste Disposal, Fluid / Q000379:methods; D014874:Water Pollutants, Chemical / Q000737:chemistry*
chemical_list: D010756:Phosphoric Acids; D014874:Water Pollutants, Chemical; D002857:Chromium; C074702:chromium hexavalent ion; D008345:Manganese; D002244:Carbon; D000535:Aluminum; D007501:Iron; C030242:phosphoric acid
keywords: Activated carbon; Assisted activation; Chromium, XPS analysis; Microwave