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Li Z.,Sun Yat Sen University | Li Z.,Pearl River Water Resources Institute | Lei H.,Sun Yat Sen University | Lou I.C.,University of Macau
Desalination and Water Treatment | Year: 2012

Abstract: The combined effects of flow rate and light intensity on the characteristics of biofilm grown on three-dimensional elastic carriers were investigated in this study, to assess as well as to provide guidance for in-situ remediation of polluted ground water using biofilm method. Four identical biological reactors were used to cultivate biofilm on the carriers made from polyethylene terephthalate (PET), at varying flow rates (0.2, 0.4 and 0.8 m3·m−2·s−1) and under artificial lighting (approximately 130 μ mol photons·m−2·s−1) or dark conditions. The results showed that the characteristics of biofilm, including total biomass, extracellular polymeric substances (EPS), active biomass and microbial activity, were all significantly enhanced with increasing flow rate and under light conditions, indicating that the synergistic effect the high flow rates and stronger light on the improvement of biofilm characteristics. © 2012, Desalination Publications.


Li Z.,Pearl River Water Resources Institute | Lou I.C.,University of Macau | Lei H.,Sun Yat Sen University | Liu Y.,Sun Yat Sen University
Desalination and Water Treatment | Year: 2013

Alumina trihydrate (ATH), one of typical complexes of aluminum (Al), was selected to study its effects on the formation of biofilms settled on inert carriers made of polyethylene terephthalate (PET) filaments. Four identical biological reactors were developed to cultivate biofilms under a series of ATH concentrations. Three-dimensional elastic inert PET carriers were used as the biofilm substrata. The biofilm characteristics including the amounts of total biofilm, extracellular polymeric substances (EPS) productions, active biomass, and microbial activity, were investigated. The impact of Al toxicity on the formation of biofilms was also discussed. The results showed that the colloidal ATH was easily adhered to the inert carriers, and the effects of ATH on the formation of biofilms colonized on the inert carriers were clearly observed. Compared to the biofilm characteristics when ATH was absent, the presence of ATH could increase the amounts of total biofilm production, EPS production, active biomass, and microbial activity: when the ATH concentrations reached 0.1, 0.2, and 0.5 mg/L (as Al3+), the total biofilm amount would increase to 1.44, 2.14, and 2.60 times, respectively, and the EPS production would enhance to 1.21, 1.60, and 1.85 times, respectively. Similar ratios for EPS production were also obtained for the corresponding active biomass and microbial activity. These results suggested that ATH is beneficial to the formation of biofilms settled on inert carriers, and the impact of Al toxicity seems to be insignificant in this study on the colonized microbes and the biofilm formation, probably due to the low ATH concentration (0.5 mg/L as Al3+ in maximum) in the reactors. © 2013 Copyright Balaban Desalination Publications.


Jiang R.,Pearl River Water Resources Institute | Chai X.-S.,South China University of Technology | Zhang C.,South China University of Technology | Tang H.-L.,Pearl River Water Resources Institute | Tang H.-L.,South China University of Technology
Guang Pu Xue Yu Guang Pu Fen Xi/Spectroscopy and Spectral Analysis | Year: 2011

The present paper reports a dual wavelength spectroscopic method for the determination of chemical oxygen demand (COD) of low content samples, based on the absorption measurement at 440 and 560 nm. Since the absorptivities of Cr 3+ at these two wavelengths are the same, a net absorption from dichromate ions can be determined by subtracting the absorption at 560 nm (only contributed by Cr 3+) from the absorption at 440 nm. The results showed that the detection limit of quantification is 8.6 mg·L -1 and the relative standard deviations are in the 2%~15% range for the low COD standard samples (≤100 mg·L -1) in this proposed method. Further more, the method does not require calibration based on the standard samples. The present method is simple, reliable, and accurate; it is suitable for the application in a mass testing for low COD samples.


Wu Z.,South China University of Technology | Huang S.,South China University of Technology | Huang S.,Eco Remediation of Guangdong Regular Higher Education Institutions | Yang Y.,South China University of Technology | And 5 more authors.
Aerosol and Air Quality Research | Year: 2013

A strain of bacteria CP1 with high nitrogen removal efficiency was newly isolated from the biofilm of a biofilter for removal of NOx from flue gas. The isolate was identified as Pseudomonas aeruginosa based on its physiological and biochemical characteristics and the results of 16S rRNA gene homology analysis. The new isolate had a high denitrifying ability, removing 98.49% of the nitrate in a 24-h period under aerobic conditions, with no nitrite accumulation. With regard to the nitrogen balance, the percentage of nitrogen lost in the flask culture was estimated to be 32.3%, which was presumed to be converted to nitrogen gas. An analysis of its denitrification activity showed that the optimal C/N and temperature were 12 and 30°C-40°C, respectively. By using glucose, sodium citrate and succinate, CP1 removed nitrate with high denitrification efficiency. The change in DO did not influence the effects of denitrification when it varied from 0 to 7.2 mg/L. The results show that CP1 could be a good candidate for the process of aerobic denitrification. © Taiwan Association for Aerosol Research.


Liao X.,China Water Resources Pearl River Planning Surveying and Derigning Co. | Chen J.,China Water Resources Pearl River Planning Surveying and Derigning Co. | Chen J.,Hohai University | Zhu Y.,Pearl River Water Resources Institute | Yin K.,China Water Resources Pearl River Planning Surveying and Derigning Co.
Shuili Fadian Xuebao/Journal of Hydroelectric Engineering | Year: 2014

Based on piecewise linearization of water level- storage and discharge capacity, this article presents a new numerical-analytical formula for flood routing using the flood routing numerical approximate method. The case studies demonstrate that this simple and practical method reachs the same calculation accuracy as the fourth order Runge-Kutta method proposed by Professor Chen Shouyu, therefore, it is promising to widely apply it to reservoir flood routing.


PubMed | Pearl River Water Resources Institute
Type: Journal Article | Journal: Guang pu xue yu guang pu fen xi = Guang pu | Year: 2011

The present paper reports a dual wavelength spectroscopic method for the determination of chemical oxygen demand (COD) of low content samples, based on the absorption measurement at 440 and 560 nm. Since the absorptivities of Cr3+ at these two wavelengths are the same, a net absorption from dichromate ions can be determined by subtracting the absorption at 560 nm (only contributed by Cr3+) from the absorption at 440 nm The results showed that the detection limit of quantification is 8.6 mg x L(-1) and the relative standard deviations are in the 2%-15% range for the low COD standard samples (< or = 100 mg x L(-1)) in this proposed method. Further more, the method does not require calibration based on the standard samples. The present method is simple, reliable, and accurate; it is suitable for the application in a mass testing for low COD samples.

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