Li T.,Tongji University |
Tan Q.,Wallingford Software China |
Zhu S.,Shanghai Water Authority
Water and Environment Journal | Year: 2010
The overflow frequencies of combined sewer systems (CSSs) along Suzhou Creek in Shanghai are definitely lower compared with low interception ratio and design expectation. This noteworthy phenomenon was analysed and the results indicate that large sewer storage capacity due to a dense interconnection between sewer systems, flat pipe slope and pump drainage pattern, as well as the spatial-temporal difference of rainfall on a large catchment that is integrated by the connected network, lead to the overflow frequencies of combined sewer overflows (CSOs) along Suzhou Creek that are much less than those of designed and of Japanese counterparts. The drainage hydraulic model was used to simulate the performance of typical CSSs in Shanghai centre area to further explain the phenomenon. Meanwhile, as separate systems have serious illicit connections and are subject to heavy wet weather pollution in Shanghai, separate systems did not show the expected advantage in nonpoint pollution control. Thus, keeping old CSSs in the Shanghai downtown area seems to be of great value with respect to the control of urban non-point pollution. © 2009 The Authors. Journal compilation © 2009 CIWEM.
Zhou Z.,Shanghai University of Electric Power |
Xing C.,Shanghai University of Electric Power |
Wu Z.,Tongji University |
Tang J.,Shanghai Water Authority |
And 2 more authors.
Desalination and Water Treatment | Year: 2015
An evaluation method based on the supply and demand of carbon source in the biological nutrient removal (BNR) process, combined with an index of difficulty of nutrient removal (DNR), was put forward to achieve comprehensive assessment and analysis of the BNR potential of wastewater treatment plants (WWTPs). Twenty-five full-scale municipal WWTPs with different BNR processes were evaluated over a period of 12 months in Shanghai (China). Statistical analysis results showed that the DNR index had significant positive correlation (r > 0.790, p < 0.01) with total nitrogen, total phosphorus concentrations in the effluent, and yielded higher correlation coefficient with BNR efficiency than the C/N and C/P ratios that were conventionally used to estimate carbon source supply conditions. According to the WWTPs ranking by DNR evaluation, the number of WWTPs with low, medium, high, and extremely high DNR level was 8, 10, 6, and 1 among the 25 WWTPs, respectively. The developed method can evaluate and analyze the BNR potential scientifically and objectively, and the ranking results can be used to guide level-to-level management, upgrading, and optimization of WWTPs under different discharge standards. © 2013, © 2013 Balaban Desalination Publications. All rights reserved.
Hu Z.,Shanghai Ocean University |
Wang S.,Shanghai Ocean University |
Wu H.,Shanghai Ocean University |
Chen Q.,Shanghai Water Authority |
And 3 more authors.
Chinese Journal of Oceanology and Limnology | Year: 2014
Using multi-mesh gillnets and trawls, the fish communities in Dianshan Lake at 6 stations from Oct. 2009 to Jul. 2010 were investigated seasonally to reveal the biodiversity and its spatial and temporal distribution patterns. The long-term changes in their structural characteristics were then analyzed to identify the main influencing factors and several measures for lake restoration were put forward. Thirty six species, belonging to 9 family and 30 genera, were collected, amongst which, the order Cypriniformes accounted for 61.1% of the total species number. In terms of importance value, Cypriniformes was the predominant group, Coilia nasus the dominant species, while Cyprinus carpio and Rhinogobius giurinus were the subdominant taxa. The community types did not differ among stations, but between seasons. There were no significant differences between seasons and among stations in species diversity, but richness differed both spatially and seasonally. Along with the process of eutrophication and the drastic reduction of the area colonized by macrophytes from 1959 to 2009-2010, the fish diversity declined markedly, and species numbers of herbivores and piscivores declined proportionately more than those of invertivores, omnivores, and planktivores. The decline of potamophilus and river-lake migratory fish was more marked than those of sedentary, river-sea migratory, and estuarine fishes. Eutrophication concomitant with sharp reduction of macrophyte area and overfishing may be the main reasons for the decline in fish diversity in Dianshan Lake. © 2014 Chinese Society for Oceanology and Limnology, Science Press and Springer-Verlag Berlin Heidelberg.