Performance of A Sludge Reduction System on Removal of Nitrogen and Phosphorous Controlled by Low Dissolved Oxygen

The influences of dissolved oxygen (DO) on the removal process of nitrogen and phosphorous in a sludge reduction system had been studied by controlling aeration amounts. It was found that under the conditions of low doses of 2,4,5trichlorophenol (TCP), endogenous sour values of activated sludge increased with the extension of low DO state duration in SBR system and the decrease of cyclic average DO, which led to a low DO environment favored the formation of simultaneous nitrification and denitrification(SND).TCP concentration was recommended as 2mg / L and cyclic average DO value in SBR system was kept at 2mg / L based on the impacts of TCP concentration on sludge reduction, removal of nitrogen and phosphorous and sludge performance. Compared with the control system, aeration amounts increased by 23% and the discharge of excess sludge decreased by 34.6%. The water quality in effluents was equivalent in the aeration sludge reduction system with 2mg/LTCP, which met the discharge standards. Therefore, it was indicated that the removal of nitrogen and phosphorous and sludge reduction can obtain excellent performance in TCP system under low DO state with removing Phosphrous rich sewage.     

Research on Peng Yigang’s Landscape Planning and Design Thoughts and Methods:A Case Study of Zhangpu XiHu Park in Fujian Province

Peng Yigang is both a famous architectural theorist and a practitioner of architectural theory.His exploration in landscape planning and design is of great significance to the transition from traditional garden to modern ones.Zhangpu Xihu Park in Fujian Province is an outstanding representative of early garden planning and architectural design by Peng Yigang,which highlights the characteristics of nationality and regionality.Through the interpretation and analysis of Zhangpu Xihu Park,Peng Yigang’s design ideas and methods of garden planning and garden architecture can be understood,especially the reference and breakthrough of traditional garden planning and architectural design will provide ideological,methodological,and empirical guidance for future landscape planning and design.