Sorption of p‐nitrophenol on two Chinese soils as affected by copper

Abstract

Abstract-Heavy metals and organic contaminants often coexist in soils. However, very little information is available regarding the effect of metals on the sorption of organic contaminants onto soils and/or of organic contaminants on metal sorption. In the present study, the effect of Cu on the sorption of p-nitrophenol on two Chinese soils was investigated using a batch-equilibration method for three conditions: Copper and p-nitrophenol were sorbed simultaneously, either Cu or p-nitrophenol was sorbed previously, or the soil colloidal phase was removed in part previously. The results suggested that Cu suppressed the sorption of p-nitrophenol on soils, whereas p-nitrophenol had little effect on Cu sorption because of the higher affinity of Cu for soils. Mechanisms of the Cu suppression effect were suggested by the results. First, large hydrated Cu occupy the siloxane surface of soils and prevent nonspecific interaction between p-nitrophenol and soils. Second, the soil colloidal phase is an effective adsorbent of p-nitrophenol; thus, more p-nitrophenol is retained in the aqueous phase. In addition, the aggregation of the colloidal particles may occur, which blocks soil pores, thereby decreasing the sorption of p-nitrophenol on the solid soil phase. Third, x-ray absorption spectroscopy revealed that Cu forms inner-sphere complexes with the carboxyl and hydroxyl functional moieties of the soil particles (clay minerals and organic matter). Fourier-transform infrared spectroscopy study indicated that these groups also react with p-nitrophenol through H-bond formation. These results suggested that Cu and p-nitrophenol have common sorption sites, at least in the soil organic matter domain, which is partially responsible for the observed overall Cu suppression effect.

Adsorption and desorption of carbendazim and cadmium in typical soils in northeastern China as affected by temperature

“…SOM is the most important component for the adsorption of carbendazim and Cd. Pei et al (2006) discovered that Cu formed inner-sphere complexes with carboxyl and hydroxyl functional groups of soil particles, which also react with p-nitrophenol through H-bond formation, using the X-ray adsorption spectroscopy coupled with the Fourier transform infrared spectroscopy. Similar inner-sphere complexes of Cd might be generated and the ΔH Θ values of carbendazim adsorption also suggested that H-bond was the main interaction.…”

Adsorption of 2,4,6-trichlorophenol by multi-walled carbon nanotubes as affected by Cu(II)

“…Electron beam energy was 2.2 GeV with a storage ring beam current of 80 mA. Sample preparation and data collection followed the methods described in our w a t e r r e s e a r c h 4 3 ( 2 0 0 9 ) 2 4 0 9 -2 4 1 8 previous research (Pei et al, 2006). Briefly, data analysis was performed with WinXAS2.1 following background correction and normalization, Cubic spline, Fourier transformation and reverse Fourier transformation, and EXAFS fitting.…”

“…However, contaminants often exist in mixtures in the environment, where they may affect each other's sorption. Heavy metals and organic contaminants coexist at many contaminated sites (Dai et al, 2007;Sprovieri et al, 2007), and coexisting heavy metal ions affect the adsorption of organic contaminants to soil, peat and charcoal (Pei et al, 2006(Pei et al, , 2007Chen et al, 2007). A few studies have been reported on competitive sorption between metals (Li et al, 2003b) or between organic contaminants on CNTs (Yang et al, 2006b).…”

Effect of lead on the sorption of phenol onto montmorillonites and organo-montmorillonites

“…There are few reports available in this field [29,30]. In the present study, Pb and phenol were chosen as representatives of heavy metals and toxic organic pollutants, respectively.…”