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Zhang S.,University of Jinan | Yang J.,University of Jinan | Xin X.,Jinan Water and Waste Water Monitoring Center | Yan L.,University of Jinan | And 2 more authors.
Environmental Progress and Sustainable Energy | Year: 2015

Chromium(VI) removal is important for wastewater treatment, and adsorption is an efficient treatment process. In this paper, natural bentonite was exchanged to sodium bentonite (Na-Bent) by adding NaCl. Hydroxy-alumina pillared bentonite (OH-Al-Bent), octadecyltrimethylammonium chloride modified bentonite (OTMAC-Bent) and organicinorganic pillared bentonite (OTMAC-OH-Al-Bent) were prepared via exchange reaction and then characterized through FTIR and BET measuring. Batch experiments were conducted on adsorption of Cr(VI) by the prepared modified bentonites. The results showed that the adsorption of Cr(VI) by Na-Bent and natural bentonite was neglected due to their weak adsorption performance. The adsorption capacity of Cr(VI) on OH-Al-Bent was much lower than on OTMAC-Bent and OTMAC-OH-Al-Bent. The adsorption isotherms of Cr(VI) by OTMAC-OH-Al-Bent and OTMAC-Bent both fit well with Freundlich and Langmuir adsorption model and the adsorption kinetics data of Cr(VI) fit well with the pseudo-secondorder model. The adsorption efficiency was over 90%, suggesting that OTMAC-OH-Al-Bent and OTMAC-Bent were excellent adsorbents for effective Cr(VI) removal from aqueous solution. © 2014 American Institute of Chemical Engineers.

Liu Y.-M.,Shandong University | Wang M.-H.,Shandong University | Jia R.-B.,Jinan Water and Waste Water Monitoring Center | Li L.,Shandong University
Desalination and Water Treatment | Year: 2012

In the present study, the biocontrol of harmful algae by an algicidal bacterium Aeromonas sp. strain FM was examined. The threshold concentration of FM for its algicidal activity against the exponentially growing Microcystis aeruginosa was 2.1×108 cfumL-1. The influence of temperature on algae removal was tested, and the result indicated that the summer temperature 30°C favored the algicidal activity of the bacterium strain when compared to 20°C, the representative temperature of spring or autumn. A strong algicidal effect of strain FM was observed against M. aeruginosa, M. flos-aquae, Anabaena cylindrica, A. flos-aquae, and Nodularia spumigena. Based on these tests, the removal of M. aeruginosa treated by Aeromonas sp. strain FM harboring in Aquamats was carried out. After 7 d treatment, M. aeruginosa at 7.5×105 cellsmL-1 with a total volume of 10 L decreased 85% of its biomass, following with a decay of the inoculated algicidal strain FM. The electron microscope images demonstrated that the strain severely damaged the cell wall of M. aeruginosa. The results of the present study indicated the application potential of the biocontrol of harmful algae by algicidal bacteria. © 2012 Desalination Publications.

Yang H.-Y.,Shandong University | Jia R.-B.,Jinan Water and Waste Water Monitoring Center | Chen B.,Shandong University | Li L.,Shandong University
Environmental Science and Pollution Research | Year: 2014

This study investigates the ability of Rhodococcus sp. strain p52, a dioxin degrader, to biodegrade petroleum hydrocarbons. Strain p52 can use linear alkanes (tetradecane, tetracosane, and dotriacontane), branched alkane (pristane), and aromatic hydrocarbons (naphthalene and phenanthrene) as sole carbon and energy sources. Specifically, the strain removes 85.7 % of tetradecane within 48 h at a degradation rate of 3.8 mg h−1 g−1 dry cells, and 79.4 % of tetracosane, 66.4 % of dotriacontane, and 63.9 % of pristane within 9–11 days at degradation rates of 20.5, 14.7, and 20.3 mg day−1 g−1 dry cells, respectively. Moreover, strain p52 consumes 100 % naphthalene and 55.3 % phenanthrene within 9–11 days at respective degradation rates of 16 and 12.9 mg day−1 g−1 dry cells. Metabolites of the petroleum hydrocarbons by strain p52 were analyzed. Genes encoding alkane-hydroxylating enzymes, including cytochrome P450 (CYP450) enzyme (CYP185) and two alkane-1-monooxygenases, were amplified by polymerase chain reaction. The transcriptional activities of these genes in the presence of petroleum hydrocarbons were detected by reverse transcription-polymerase chain reaction. The results revealed potential of strain p52 to degrade petroleum hydrocarbons. © 2014, Springer-Verlag Berlin Heidelberg.

Liu S.Q.,University of Jinan | Chen Y.F.,University of Jinan | Wang L.G.,University of Jinan | Jia R.B.,Jinan Water and Waste Water Monitoring Center
Advanced Materials Research | Year: 2011

It is well known that microcystins (MCs) are the most abundant toxins produced by cyanobacteria in freshwater. The separation and characterization of MCs isomers are very important to the research of algal pollution in freshwater. In this paper MCs isomers were extracted by using methanol water solution and separated by reverse phase high performance liquid chromatography (HPLC). The different isomers were characterized by using HPLC-MS method. Different ratio of extract solvent and chromatographic conditions were discussed. Five MCs isomers were successfully extracted from cyanobacteria of Dianchi Lake. Three of which were characterized to be MC-RR, MC-YR and MC-LR, 1.5mg (92.3 purity) of MC-LR was prepared by using a semi-preparation HPLC system. © (2011) Trans Tech Publications.

Liu Y.,Shandong University | Li L.,Shandong University | Jia R.,Jinan Water and Waste Water Monitoring Center
Procedia Environmental Sciences | Year: 2011

Redfield ratio about 16N:1P indicates the atomic ratio of the average elemental composition of phytoplankton, and the initial ratio of resource availability in a system provides the capacity to support algae biomass. Field and laboratory studies, focusing on the natural aquatic environment without disturbance, obtain regular growth of Microcystis aeruginosa with varied Redfield ratios. However, whether there are similar rules of M. aeruginosa under severely disturbing conditions remains unclear. In this study, we reported the growth of M. aeruginosa under conditions with excessive input of nitrogen and phosphorus, which may serve as clues to the control of M. aeruginosa blooming. Growth of M. aeruginosa was monitored in semi-continuous cultures with abundant supply of nitrogen and phosphorus. Effect of nitrogen, phosphorus and their ratio on growth of M. aeruginosa was examined, and the uptake of nitrogen and phosphorus under different nutrient conditions was compared. The effect of N:P ratio depended on the concentration of nitrogen and phosphorus. When initial nitrogen concentration was at 10 mg l-1 and the N:P ratio of 16, the algae growth displayed the highest maximum cell yield and the longest exponential growth. The maximum uptake of nitrogen and phosphorus reached at the N:P ratio of 16, consistent to the maximum yield. On the other hand, when initial phosphorus concentration was around 1 mg l-1, the highest maximum cell yield and the longest exponential growth occurred at the N:P ratio of 40. The ratio of 40 also favored the uptake of phosphorus, while the uptake of nitrogen increased with the increase of nitrogen concentration. © 2011 Published by Elsevier Ltd.

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