The denitrifying sulfide removal(DSR) process has recently been studied extensively from an engineering perspective. However, the importance of microbial communities of this process was generally underestimated. In th...The denitrifying sulfide removal(DSR) process has recently been studied extensively from an engineering perspective. However, the importance of microbial communities of this process was generally underestimated. In this study, the microbial community structure of a lab-scale DSR reactor was characterized in order to provide a comprehensive insight into the key microbial groups in DSR system. Results from high-throughput sequencing analysis revealed that the fraction of autotrophic denitrifiers increased from 2.34 % to 10.93% and 44.51% in the DSR system when the influent Na Cl increased from 0 g/L, to 4 g/L and 30 g/L, respectively. On the contrary, the fraction of heterotrophic denitrifiers decreased from 61.74% to 39.57%, and 24.12%, respectively. Azoarcus and Thiobacillus were the main autotrophic denitrifiers, and Thauera was the main hetetrophic denitrifier during the whole process. This study could be useful for better understanding the interaction between autotrophs and heterotrophs in DSR system.展开更多
Alkaline pretreatment is an effective technology to disintegrate sewage sludge, where alkali dosage and sludge concentration are two important factors. p H value or alkali concentration is usually adjusted in order to...Alkaline pretreatment is an effective technology to disintegrate sewage sludge, where alkali dosage and sludge concentration are two important factors. p H value or alkali concentration is usually adjusted in order to determine a proper dosage of alkali. Our work has found that this is not a good strategy. A new parameter, the ratio of alkali to sludge(Ra/s), is more sensitive in controlling the alkali dosage. The sludge concentration Csand retention time t are two other important factors to consider. The validity of these arguments is confirmed with modeling and experiments. The individual effect of Ra/s, Csand t was studied separately. Then the combined effect of these three factors was evaluated. The sludge disintegration degree of 44.7% was achieved with the optimized factors. Furthermore, an alkaline-microwave combined pretreatment process was carried out under these optimized conditions. A high disintegration degree of 62.3% was achieved while the energy consumption of microwave was much lower than previously reported.展开更多
This paper presents the data from two-year experiments concerning with doses of sewage sludge （0, 7, 14 and 21 ton.ha^-1） and inorganic nitrogen doses （0, 50, 100 and 150 kg.ha^-1） from the Municipality of Van, wh...This paper presents the data from two-year experiments concerning with doses of sewage sludge （0, 7, 14 and 21 ton.ha^-1） and inorganic nitrogen doses （0, 50, 100 and 150 kg.ha^-1） from the Municipality of Van, which is located at an altitude of 1,725 m of eastern Anatolia in Turkey. A study was conducted to assess two different N sources on sandy-silty-clay soils grown to crested wheatgrass Agropyron cristatum （L.） Gaertn, grass pasture which had been amended with sewage sludge for two years. Plant tissue and DTPA （diethylenetriamine pentaacetic acid） extractable soil nutrient were evaluated; twelve elements were analyzed in the plant tissue and six elements in the soil extract in different soil depths. The research demonstrated that the applications produced increase contents of N, P, Mg, Mn, Zn and Pb in the plant. There was a significant （P 〈 0.01） accumulation of DTPA extractable concentrations of Fe, Mn, Cu, Zn and Pb in the top soil horizon. Also, sewage sludge resulted in 51 folded increase in extractable P in 0-20 cm soil horizon. However, DTPA concentrations of in soil showed that Fe exhibited a significant positive correlation with the concentrations of exchangeable fractions of Mn, Cu, Zn and Pb with the correlation. Positive correlations were also observed between Cu-Mn, Mn-Zn, Mn-Pb, Cu-Zn, Cu-Pb and Zn-Pb concentrations. In the same way, plant uptake of the Mn, Zn and Pb was highly correlated with concentrations of Cu, Zn and Pb in the soil. It was concluded that sewage sludge is a valuable source of nutrient and also provides an opportunity to increase soil organic matter.展开更多
基金supported by the National Natural Science Foundation of China under Grant No.21307160the Natural Science Foundation of Shandong Province under Grant No.ZR2013EEQ030the Fundamental Research Funds for the Central Universities under Grant No.R1404005A
文摘The denitrifying sulfide removal(DSR) process has recently been studied extensively from an engineering perspective. However, the importance of microbial communities of this process was generally underestimated. In this study, the microbial community structure of a lab-scale DSR reactor was characterized in order to provide a comprehensive insight into the key microbial groups in DSR system. Results from high-throughput sequencing analysis revealed that the fraction of autotrophic denitrifiers increased from 2.34 % to 10.93% and 44.51% in the DSR system when the influent Na Cl increased from 0 g/L, to 4 g/L and 30 g/L, respectively. On the contrary, the fraction of heterotrophic denitrifiers decreased from 61.74% to 39.57%, and 24.12%, respectively. Azoarcus and Thiobacillus were the main autotrophic denitrifiers, and Thauera was the main hetetrophic denitrifier during the whole process. This study could be useful for better understanding the interaction between autotrophs and heterotrophs in DSR system.
基金the National Natural Science Foundation of China(51078234)Shenzhen R&D fund(JCYJ20140418193546101)Shenzhen University R&D fund(T201203)
文摘Alkaline pretreatment is an effective technology to disintegrate sewage sludge, where alkali dosage and sludge concentration are two important factors. p H value or alkali concentration is usually adjusted in order to determine a proper dosage of alkali. Our work has found that this is not a good strategy. A new parameter, the ratio of alkali to sludge(Ra/s), is more sensitive in controlling the alkali dosage. The sludge concentration Csand retention time t are two other important factors to consider. The validity of these arguments is confirmed with modeling and experiments. The individual effect of Ra/s, Csand t was studied separately. Then the combined effect of these three factors was evaluated. The sludge disintegration degree of 44.7% was achieved with the optimized factors. Furthermore, an alkaline-microwave combined pretreatment process was carried out under these optimized conditions. A high disintegration degree of 62.3% was achieved while the energy consumption of microwave was much lower than previously reported.
文摘This paper presents the data from two-year experiments concerning with doses of sewage sludge （0, 7, 14 and 21 ton.ha^-1） and inorganic nitrogen doses （0, 50, 100 and 150 kg.ha^-1） from the Municipality of Van, which is located at an altitude of 1,725 m of eastern Anatolia in Turkey. A study was conducted to assess two different N sources on sandy-silty-clay soils grown to crested wheatgrass Agropyron cristatum （L.） Gaertn, grass pasture which had been amended with sewage sludge for two years. Plant tissue and DTPA （diethylenetriamine pentaacetic acid） extractable soil nutrient were evaluated; twelve elements were analyzed in the plant tissue and six elements in the soil extract in different soil depths. The research demonstrated that the applications produced increase contents of N, P, Mg, Mn, Zn and Pb in the plant. There was a significant （P 〈 0.01） accumulation of DTPA extractable concentrations of Fe, Mn, Cu, Zn and Pb in the top soil horizon. Also, sewage sludge resulted in 51 folded increase in extractable P in 0-20 cm soil horizon. However, DTPA concentrations of in soil showed that Fe exhibited a significant positive correlation with the concentrations of exchangeable fractions of Mn, Cu, Zn and Pb with the correlation. Positive correlations were also observed between Cu-Mn, Mn-Zn, Mn-Pb, Cu-Zn, Cu-Pb and Zn-Pb concentrations. In the same way, plant uptake of the Mn, Zn and Pb was highly correlated with concentrations of Cu, Zn and Pb in the soil. It was concluded that sewage sludge is a valuable source of nutrient and also provides an opportunity to increase soil organic matter.
