Environ Sci Pollut Res DOI 10.1007/s11356-014-2627-z
RESEARCH ARTICLE
Adsorption characteristics of Cu(II) from aqueous solution onto biochar derived from swine manure Jun Meng & Xiaoli Feng & Zhongmin Dai & Xingmei Liu & Jianjun Wu & Jianming Xu
Received: 27 October 2013 / Accepted: 5 February 2014 # Springer-Verlag Berlin Heidelberg 2014
Abstract The purpose of this study was to investigate adsorption characteristic of swine manure biochars pyrolyzed at 400 °C and 700 °C for the removal of Cu(II) ions from aqueous solutions. The biochars were characterized using BET surface area, Fourier transform infrared spectroscopy (FTIR), zeta potential, scanning electron microscopy/energy dispersive spectrometer (SEM–EDS), and X-ray diffraction (XRD). The adsorption of Cu(II) ions by batch method was carried out and the optimum conditions were investigated. The adsorption processes of these biochars are well described by a pseudo-second-order kinetic model, and the adsorption isotherm closely fitted the Sips model. Thermodynamic analysis suggested that the adsorption was endothermic. The maximum Cu(II) adsorption capacities of biochars derived from fresh and composted swine manure at 400 °C were 17.71 and 21.94 mg g−1, respectively, which were higher than those at 700 °C. XRD patterns indicated that the silicate and phosphate particles within the biochars served as adsorption sites for Cu(II). The removal of Cu(II) ions from industrial effluent indicated that the fresh swine manure biochar pyrolyzed at 400 °C can be considered as an effective adsorbent. Keywords Adsorption . Copper . Biochar . Swine manure . Pyrolysis . Plating wastewater
Responsible editor: Angeles Blanco J. Meng : X. Feng : Z. Dai : X. Liu (*) : J. Wu : J. Xu (*) Institute of Soil and Water Resources and Environmental Science, Zhejiang Provincial Key Laboratory of Subtropical Soil and Plant Nutrition, Zhejiang University, Hangzhou 310058, China e-mail: [email protected] e-mail: [email protected]
Introduction Copper (Cu) is one of the heavy metals widely used in industrial processes such as mining and smelting, electroplating, brass manufacture, petroleum refining and in the manufacture of some agrochemicals (Demirbas et al. 2009). Wastewater from these industries is the main anthropogenic source of Cu. Although Cu is an essential metal for all known living organisms at lower concentration, excessive intake of Cu(II) causes kidney damage, severe headaches, hair loss, hypoglycemia, increased heart rate, nausea, widespread capillary damage and central nervous problems (Pellera et al. 2012). The World Health Organization (WHO) recommends that the maximum acceptable concentration of Cu(II) in drinking water is 1.5 mg l−1 (WHO 2006). Therefore, wastewater containing high concentration of Cu(II) and other heavy metal ions must be treated before being discharged. Conventional methods such as chemical precipitation, reverse osmosis, neutralization, evaporation, chemical oxidation and reduction, ion exchange and adsorption have been proposed for the removal of Cu(II) and other heavy metals from wastewater (Rich and Cherry 1987; Basha et al. 2008). Among these methods, adsorption techniques are frequently applied because of their highly efficiency, low cost, ease of operation and insensitivity to toxic substances (Aydın et al. 2008). Currently, biomass-derived biochars have been used as effective adsorbents to remove heavy metals and/ or organic compounds from aqueous solutions (Cao et al. 2009; Xu et al. 2013; Zhang et al. 2013). However, the cost is high for large scale wastewater treatment and adsorption capacities are highly dependent on the properties of the biochars (Keiluweit et al. 2010). Therefore, there is a need to investigate relatively low-cost and high adsorption capacity adsorbents. Several research workers have studied the production of biochar from feedstocks such as sewage sludge, industrial wastes, plant residues, and animal manures (Cao et al. 2009; Chen et al. 2011; Wang et al. 2011; Meng et al. 2013; Shahtalebi et al. 2013).
Environ Sci Pollut Res
Among these feedstocks, animal manures may be potentially suitable for the production of biochar (Lima et al. 2007; Ro et al. 2010; Xu et al. 2013). The intensification of swine production has largely led to increased amounts of manure as a by-product. In 2003, global swine waste production was estimated at 460 million metric tons (Graham et al. 2008). Converting swine manure into biochar can reduce its adverse environmental problems, and also produce renewable energy and value-added biochar (Hooda et al. 2000; Ro et al. 2010). Several manure-derived biochars have been studied for their adsorptive capacity in the removal of heavy metals from aqueous solutions (Cao et al. 2009; Guo et al. 2010; Ippolito et al. 2012; Xu et al. 2013). However, systematic studies of Cu(II) adsorption characteristics on fresh and composted swine manures under different parameters and their associated adsorption mechanisms are limited. The main purpose of this study was to investigate the adsorption characteristics of Cu(II) ions from aqueous solutions using biochars produced from fresh and composted swine manures at two pyrolysis temperatures. Adsorption experiments were carried out to investigate the effects of solution pH, adsorbent concentration, contact time, initial concentration, and temperature on the adsorption process. To understand the adsorption process, the adsorption kinetics, isotherms and thermodynamics were further studied using data obtained from these experiments. The mechanisms responsible for the Cu(II) removal by these four biochars were characterized using BET surface area, Fourier transform infrared spectroscopy (FTIR), zeta potential, scanning electron microscopy (SEM) equipped with energy dispersive spectrometer (EDS), and X-ray diffraction (XRD).
Materials and methods Biochar preparation Fresh and composted swine manures were collected from an intensive swine production unit, located in Hangzhou, China. The samples were air-dried and then sieved
RESEARCH ARTICLE
Adsorption characteristics of Cu(II) from aqueous solution onto biochar derived from swine manure Jun Meng & Xiaoli Feng & Zhongmin Dai & Xingmei Liu & Jianjun Wu & Jianming Xu
Received: 27 October 2013 / Accepted: 5 February 2014 # Springer-Verlag Berlin Heidelberg 2014
Abstract The purpose of this study was to investigate adsorption characteristic of swine manure biochars pyrolyzed at 400 °C and 700 °C for the removal of Cu(II) ions from aqueous solutions. The biochars were characterized using BET surface area, Fourier transform infrared spectroscopy (FTIR), zeta potential, scanning electron microscopy/energy dispersive spectrometer (SEM–EDS), and X-ray diffraction (XRD). The adsorption of Cu(II) ions by batch method was carried out and the optimum conditions were investigated. The adsorption processes of these biochars are well described by a pseudo-second-order kinetic model, and the adsorption isotherm closely fitted the Sips model. Thermodynamic analysis suggested that the adsorption was endothermic. The maximum Cu(II) adsorption capacities of biochars derived from fresh and composted swine manure at 400 °C were 17.71 and 21.94 mg g−1, respectively, which were higher than those at 700 °C. XRD patterns indicated that the silicate and phosphate particles within the biochars served as adsorption sites for Cu(II). The removal of Cu(II) ions from industrial effluent indicated that the fresh swine manure biochar pyrolyzed at 400 °C can be considered as an effective adsorbent. Keywords Adsorption . Copper . Biochar . Swine manure . Pyrolysis . Plating wastewater
Responsible editor: Angeles Blanco J. Meng : X. Feng : Z. Dai : X. Liu (*) : J. Wu : J. Xu (*) Institute of Soil and Water Resources and Environmental Science, Zhejiang Provincial Key Laboratory of Subtropical Soil and Plant Nutrition, Zhejiang University, Hangzhou 310058, China e-mail: [email protected] e-mail: [email protected]
Introduction Copper (Cu) is one of the heavy metals widely used in industrial processes such as mining and smelting, electroplating, brass manufacture, petroleum refining and in the manufacture of some agrochemicals (Demirbas et al. 2009). Wastewater from these industries is the main anthropogenic source of Cu. Although Cu is an essential metal for all known living organisms at lower concentration, excessive intake of Cu(II) causes kidney damage, severe headaches, hair loss, hypoglycemia, increased heart rate, nausea, widespread capillary damage and central nervous problems (Pellera et al. 2012). The World Health Organization (WHO) recommends that the maximum acceptable concentration of Cu(II) in drinking water is 1.5 mg l−1 (WHO 2006). Therefore, wastewater containing high concentration of Cu(II) and other heavy metal ions must be treated before being discharged. Conventional methods such as chemical precipitation, reverse osmosis, neutralization, evaporation, chemical oxidation and reduction, ion exchange and adsorption have been proposed for the removal of Cu(II) and other heavy metals from wastewater (Rich and Cherry 1987; Basha et al. 2008). Among these methods, adsorption techniques are frequently applied because of their highly efficiency, low cost, ease of operation and insensitivity to toxic substances (Aydın et al. 2008). Currently, biomass-derived biochars have been used as effective adsorbents to remove heavy metals and/ or organic compounds from aqueous solutions (Cao et al. 2009; Xu et al. 2013; Zhang et al. 2013). However, the cost is high for large scale wastewater treatment and adsorption capacities are highly dependent on the properties of the biochars (Keiluweit et al. 2010). Therefore, there is a need to investigate relatively low-cost and high adsorption capacity adsorbents. Several research workers have studied the production of biochar from feedstocks such as sewage sludge, industrial wastes, plant residues, and animal manures (Cao et al. 2009; Chen et al. 2011; Wang et al. 2011; Meng et al. 2013; Shahtalebi et al. 2013).
Environ Sci Pollut Res
Among these feedstocks, animal manures may be potentially suitable for the production of biochar (Lima et al. 2007; Ro et al. 2010; Xu et al. 2013). The intensification of swine production has largely led to increased amounts of manure as a by-product. In 2003, global swine waste production was estimated at 460 million metric tons (Graham et al. 2008). Converting swine manure into biochar can reduce its adverse environmental problems, and also produce renewable energy and value-added biochar (Hooda et al. 2000; Ro et al. 2010). Several manure-derived biochars have been studied for their adsorptive capacity in the removal of heavy metals from aqueous solutions (Cao et al. 2009; Guo et al. 2010; Ippolito et al. 2012; Xu et al. 2013). However, systematic studies of Cu(II) adsorption characteristics on fresh and composted swine manures under different parameters and their associated adsorption mechanisms are limited. The main purpose of this study was to investigate the adsorption characteristics of Cu(II) ions from aqueous solutions using biochars produced from fresh and composted swine manures at two pyrolysis temperatures. Adsorption experiments were carried out to investigate the effects of solution pH, adsorbent concentration, contact time, initial concentration, and temperature on the adsorption process. To understand the adsorption process, the adsorption kinetics, isotherms and thermodynamics were further studied using data obtained from these experiments. The mechanisms responsible for the Cu(II) removal by these four biochars were characterized using BET surface area, Fourier transform infrared spectroscopy (FTIR), zeta potential, scanning electron microscopy (SEM) equipped with energy dispersive spectrometer (EDS), and X-ray diffraction (XRD).
Materials and methods Biochar preparation Fresh and composted swine manures were collected from an intensive swine production unit, located in Hangzhou, China. The samples were air-dried and then sieved
