An Empirical Study on the Development of Regional Circular Economy Based on Ecological Efficiency： A Case Study of Jiangsu Province

Based on the theory of ecological efficiency,an empirical study on ecological efficiency and its changing path in Jiangsu Province during2005-2014 was conducted,and then the relationship between economic development and environmental pressure in the province was discussed by decoupling analysis. Finally,the main influencing factors of changes in ecological efficiency were analyzed by grey relational analysis method. The results showed that from 2005 to 2014,the resource efficiency of each indicator in Jiangsu Province fluctuated,while the environmental efficiency of most indicators increased slightly. The comprehensive resource efficiency and environmental efficiency also fluctuated,and the fluctuation range of the comprehensive environmental efficiency was larger than that of the comprehensive resource efficiency. Seen from the temporal evolution of ecological efficiency and circulation economy development pattern in Jiangsu Province,the leaping development mode was adopted in the province.The decoupling state of economic development and environmental pressure in Jiangsu Province was unstable,and they were in a state of strong decoupling,weak decoupling and expensive recoupling in most years. According to the results of grey relational analysis,comprehensive utilization of solid waste,industrial electricity consumption,electricity consumption of the whole society,domestic energy consumption,discharge of urban domestic sewage,and production of common industrial solid waste were the main influencing factors of changes in ecological efficiency in Jiangsu Province.

Study on Water Conservation Capacity of Litter from Different Types of Forest in Caohai Basin

[Objective]The research aimed to understand water conservation capacity of litter from different forest types in Caohai basin. [Method] Current storage amount,water holding capacity and precipitation interception ability of litter from 4 types of forest were investigated and studied. [Result]The order of exist litter amount was grass slope ＆gt;shrub forest ＆gt;mixed broad leaf-conifer forest ＆gt;coniferous forest. The order of natural water holding capacity was mixed broad leafconifer forest ＆gt; coniferous forest ＆gt; grass slope ＆gt; shrub forest. The relevance between water holding capacity of litter and soaking time was in line with this formula： y = kln（ x） ＋ b. During 0-120 min of litter soaking,water holding capacity increased rapidly. After 120 min,the increasing trend remained flat until closing to the maximum water holding capacity. The relevance between water absorption rate of litter and soaking time was in line with this formula： y = a ＋ bx-1. In the beginning of soaking,water absorption rates of litter from different woodlands showed great difference. As soaking time went by,water absorption rates of litter from different woodlands all declined sharply. During 0-120 min,declining velocity of water absorption rate was quicker. After 120 min,the declining trend tended to be slow. The maximum water holding capacity of litter presented the order of shrub forest ＆gt; mixed broad leafconifer forest ＆gt; grass slope ＆gt; coniferous forest. The maximum precipitation interception amount of litter presented the order of shrub forest ＆gt; grass slope ＆gt; mixed broad leafconifer forest ＆gt; coniferous forest. Effective impounding capacity of litter presented the order of shrub forest ＆gt; mixed broad leafconifer forest ＆gt; grass slope ＆gt; coniferous forest. [Conclusion]The research could provide support for the construction of water conservation forest in Caohai basin.

SPATIAL AND TEMPORAL VARIABILITY OF NORTHWEST PACIFIC TROPICAL CYCLONE ACTIVITY IN A GLOBAL WARMING SCENARIO

Utilizing the Joint Typhoon Warning Center(JTWC) and Tokyo-Typhoon Center of the Japan Meteorological Agency(JMA RSMC TOKYO) best-track tropical cyclone(TC) data for the period 1951-2014,variations in spatial and temporal characteristics of Northwest Pacific TC activity for a global warming scenario are discussed.The results suggest that since the early 1960 s,there has been an overall decreasing trend in the frequency of occurrence,intensity,peak intensity,length of movement,and lifetime of TCs.However,global wanning has led to a linearly increasing trend in TC activity in eastern Asia,which indicates that Northwest Pacific TC activity decreases,but the frequency of landfalls and intensity are likely strengthened.Therefore,the threat of TCs towards eastern Asia is enhanced.The increase in TC activity in eastern Asia is likely the result of a strengthened Walker circulation due to an increasing temperature gradient between the northwest Pacific Ocean and the central and eastern Pacific Ocean.The strengthening Walker circulation could increase the magnitude of the vertical wind shear,relative vorticity,and meridional wind shear of low-level easterlies near the equator in the tropical Northwest Pacific,which affects the spatial and temporal variations of TC activity in the Northwest Pacific.

Distribution of Phosphorus in Sediments of Onshore Reed Areas of Lake Taihu

To reveal additional effects of aquatic macrophytes on biogeochemical properties of onshore lake phosphorus and to investigate the ecological response of reed communities to this phosphorus,sediments from the Meiliangwan onshore reed area of Lake Taihu were sampled by using a columnar sampler (D=8 cm) on September 18,October 17 and December 3,2003. The samples were compared with those from macrophyte-free areas. The collected samples were dried naturally at room temperature,ground and screened with a 100 mesh sieve. The HClO4-H2SO4 digesting and H2SO4-H2O2 heating digesting methods were used to analyze the total amount of phosphorus (TP) contained in sedi-ments of the reed area and in tissues of reed roots and stems. The result shows: 1) the level of TP,from both the reed area sediment and the reference samples,is highest during the vigorous growing stage and lowest during the slow growing stage. The difference between the two levels is statistically significant (p<0.01); 2) the top layer (0-2 cm) of the sediment from the area without higher aquatic macrophytes and the sediment (4-7 cm) in the central reed area show peak values of phosphorus enrichment; 3) the phosphorus enrichment of different parts of reed tissues is in decreasing order: firous root > rhizome > stem. All are smaller in the level of phosphorous than that in rhizosphere sediments (0-2 cm).

Stable partial nitritation of mature landfill leachate in a continuous flow bioreactor:Long-term performance,microbial community evolution,and mechanisms

A continuous flow bioreactor was operated for 300 days to investigate partial nitritation(PN)of mature landfill leachate,establishing the long-term performance of the system in terms of the microbial community composition,evolution,and interactions.The stable operation phase(31-300 d)began after a 30 days of start-up period,reaching an average nitrite accumulation ratio(NAR)of 94.43%and a ratio of nitrite nitrogen to ammonia nitrogen(NO_(2)^(−)-N/NH_(4)^(+)-N)of 1.16.Some fulvic-like and humic-like compounds and proteins were effectively degraded in anaerobic and anoxic tanks,which was consistent with the corresponding abundance of methanogens and syntrophic bacteria in the anaerobic tank,and organic matter degrading bacteria in the anoxic tank.The ammonia-oxidizing bacteria(AOB)Nitrosomonas was found to be the key functional bacteria,exhibiting an increase in abundance from 0.27%to 6.38%,due to its collaborative interactions with organic matter degrading bacteria.In-situ inhibition of nitrite-oxidizing bacteria(NOB)was achieved using a combination of free ammonia(FA)and free nitrous acid(FNA),low dissolved oxygen(DO)with fewer bioavailable organics conditions were employed to maintain stable PN and a specific ratio of NO_(2)^(−)-N/NH_(4)^(+)-N,without an adverse impact on AOB.The synergistic relationships between AOB and both denitrifying bacteria and organic matter degrading bacteria,were found to contribute to the enhanced PN performance and microbial community structure stability.These findings provide a theoretical guidance for the effective application of PN-Anammox for mature landfill leachate treatment.

Speciation characterization and coagulation of poly-silica-ferric-chloride:The role of hydrolyzed Fe(Ⅲ) and silica interaction

The highly efficient inorganic polymer flocculants （IPFs） of the ferric-silica system is a new and promising coagulant. Interactions between ferric species and silica play a large part in the coagulation of suspensions. These effects are quite distinct from those associated with polymeric or colloid silica. However, although these species are key to coagulation efficiency, they have not been comprehensively discussed. A new type of coagulant, poly-silica-ferric-chloride （PFSC）, was synthesized by co-polymerization and characterized by time complexation spectroscopy and photon correlation spectroscopy. Compared with traditional ferric salt, the results indicated that PFSC had a higher molecular weight, lesser positive charge, lower Feb and higher Fec. The higher the Si/Fe ratio, the higher the silica and lower the silicac found. The PFSC with appropriate polysilica acid not only obtained better coagulation/flocculation efficiency in turbidity removal, enhanced the flocculation index （FI） and provided less residual ferric, it also lowered water treatment costs compared to traditional ferric salt. Results showed that PFSC could remove colloid particles in water by charge neutralization and sweeping, adsorption bridging mechanism.