Adsorption characteristics of atrazine (AT) onto the surfacial sediments (natural surface coating samples) were investigated via thermal adsorption in the presence of pollutants malathion (Ma) and heavy metals (cadmium and copper). The results indicate that cadmium and Ma both have synergetic effect during the adsorption of AT; at the same time, copper caused antagonistic effect on the adsorption of AT. Ma could facilitate the adsorption of AT, no matter that Ma was added after the adsorption of AT or simultaneous adsorption of AT with Ma present. However, Ma inhibited the adsorption of AT when it was added before the adsorption of AT. The adsorption of AT was also enhanced when both cadmium and Ma were present; however, it was inhibited strongly when both copper and Ma were present. The infrared spectra of the surfacial sediments (natural surface coating samples), after the adsorption of AT in the presence of co-existing pollutants, indicated that organic functional groups, such as O-H or N-H and C=O, play important roles on sorption of AT to river sediments.

A method for determination of decabrominated diphenyl ether (decaBDE), in sediment samples, at trace level has been developed using dispersive liquid-liquid microextraction based on the solidification of floating organic drop (DLLME-SFO) and high performance liquid chromatography-ultraviolet detector (HPLC-UV). The data obtained from an orthogonal array experiment were used as the training samples to establish a BP artificial neural network model for optimization of the experimental conditions with results as follows: 1.00 mL of methanol as dispersive solvent, 35.0 μL of dodecanol as extractive solvent, the mass concentration of NaCl was 10.00% at pH 5, and extraction time was 10 min. The extraction recovery (ER) of the present method was 62.22%, and the proposed method exhibited a wide linear range (3.5–1400 ng g−1) with R2 = 0.9921. The limit of detection (LOD) and the limit of quantification (LOQ) for this method were 2.3 pg g−1 (S/N = 2) and 5.6 pg g−1 (S/N = 5), respectively. The recoveries of real samples at different spiked levels of decaBDE ranged from 97.7% to 104.2%. Meanwhile, the pretreatment of DLLME-SFO for decaBDE from solid samples was simplified in this study as extraction, concentration, and separation procedures for decaBDE from the sediment sample could be carried out in a single step.

Selective extraction techniques followed by batch adsorption experiments and statistical analyses were employed to investigate the adsorption behavior of bisphenol A (BPA) onto the natural surface coatings samples (NSCSs) and surficial sediments (SSs) and estimate the relative contribution of components (i.e. Fe oxides, Mn oxides, organic materials and residues) to the total BPA adsorption. The results indicate that nonlinear Langmuir model can describe the adsorption behavior of BPA on the NSCSs and SSs before and after extraction treatments. The removal of Mn oxides from the NSCSs and SSs caused a significant increase in BPA adsorption, which implied that Mn oxides inhibited BPA adsorption onto solid matrix, and Fe oxides played a positive role in BPA adsorption onto the NSCSs and SSs. However, the removal of organic materials (OMs) led to a dramatic decrease in BPA adsorption, suggesting considerable amounts of BPA adsorbed onto OMs in the NSCSs and SSs. This study may provide important insights into the understanding of the transport and ultimate fate of BPA in the aquatic environments.