To achieve urban sustainability, it is critical to enhance the environment, economy, and society simultaneously. This study adopted the revised genuine progress indicator (GPI) and ecological footprint (EF) to evaluate the ecological efficiency and economic sustainability of the Yangtze River Delta from 2000 to 2018. Spatial analysis was utilized to identify spatial autocorrelation. A total of 27 cities were then partitioned through k-means cluster analysis. The results showed that GPI and ecological efficiency improved rapidly, but economic sustainability showed a downward trend. GPI and GDP had a high degree of spatial correlation, especially in Suzhou-Wuxi-Changzhou Metropolitan Area. However, no spatial correlation existed between GPI and EF. The city with high GEE can reach 3000 $/gha, indicating the city consumed 1 global hectare to create $3000 of genuine economic growth. Shanghai, Hangzhou, and Taizhou were cities with the highest level of economic sustainability and ecological efficiency. The spatiotemporal characteristics of economic sustainability and ecological efficiency revealed in this study will provide theoretical guidance for alleviating ecological pressure and promoting economic sustainable development.
A review of the physical characteristics of sulfur-containing aerosols, with respect to size distribution of the physical distributions, sulfur distributions, distribution modal characteristics, nuclei formation rates, aerosol growth characteristics, and in situ measurement, has been made.Physical size distributions can be characterized well by a trimodal model consisting of three additive lognormal distributions.When atmospheric physical aerosol size distributions are characterized by the trimodal model, the following typical modal parameters are observed:1. Nuclei mode – geometric mean size by volume, DGVn, from 0.015 to 0.04 μm. σgn=1.6, nucler mode volumes from 0.0005 over the remote oceans to 9 μm3 cm−3 on an urban freeway.2. Accumulation mode – geometric mean size by volume, DGVa, from 0.15 to 0.5 μm, σga=1.6–2.2 and mode volume concentrations from 1 for very clean marine or continental backgrounds to as high as 300 μm3 cm−3 under very polluted conditions in urban areas.3. Coarse particle mode – geometric mean size by volume, DGVc, from 5 to 30 μm, σgn=2–3, and mode volume concentrations from 2 to 1000 μm3 cm−3.It has also been concluded that the fine particles (Dp<2 μm) are essentially independent in formation, transformation and removal from the coarse particles (Dp>2 μm).Modal characterization of impactor-measured sulfate size distributions from the literature shows that the sulfate is nearly all in the accumulation mode and has the same size distribution as the physical accumulation mode distribution.Average sulfate aerodynamic geometric mean dia. was found to be 0.48±0.1 μm (0.37±0.1 μm vol. dia.) and σg=2.00±0.29. Concentrations range from a low of about 0.04 μg m−3 over the remote oceans to over 8 μg m−3 under polluted conditions over the continents.Review of the data on nucleation in smog chambers and in the atmosphere suggests that when SO2, is present, SO2-to-aerosol conversion dominates the Aitken nuclei count and, indirectly, through coagulation and condensation, the accumulation mode size and concentration. There are indications that nucleation is ubiquitous in the atmosphere, ranging from values as low as 2 cm−3 h−1 over the clean remote oceans to a high of 6×106 cm−3 h−1 in a power plant plume under sunny conditions.There is considerable theoretical and experimental evidence that even if most of the mass for the condensational growth of the accumulation mode comes from hydrocarbon conversion, sulfur conversion provides most of the nuclei. 相似文献
The catalytic ozonation treatment of secondary biochemical effluent for papermaking wastewater by Ag-doped nickel ferrite was investigated. Ag-doped catalysts prepared by sol-gel method were characterized, illustrating that Ag entirely entered the crystalline of NiFe2O4 and changed the surface properties. The addition of catalyst enhanced the removal efficiency of chemical oxygen demand and total organic carbon. The results of gas chromatography-mass spectrometer, ultraviolet light absorbance at 254 nm and three-dimensional fluorescence excitation-emission matrix suggested that aromatic compounds were efficiently degraded and toxic substances, such as dibutyl phthalate. In addition, the radical scavenging experiments confirmed the hydroxyl radicals acted as the main reactive oxygen species and the surface properties of catalysts played an important role in the reaction. Overall, this work validated potential applications of Ag-doped NiFe2O4 catalyzed ozonation process of biologically recalcitrant wastewater. 相似文献
Chlorpyrifos is one of the most extensively used insecticides in China. The distribution and residues of chlorpyrifos in a paddy environment were characterized under field and laboratory conditions. The half-lives of chlorpyrifos in the two conditions were 0.9–3.8 days (field) and 2.8–10.3 days (laboratory), respectively. The initial distribution of chlorpyrifos followed the increasing order of water < straw < soil, and soil was characterized as the major absorber. The ultimate residues in rice grain were below the maximum residue limit (MRL) with a harvest interval of 14 days. The chronic exposure for chlorpyrifos was rather low compared to the acceptable daily intake (ADI = 0.01 mg/kg bw) due to rice consumption. The chronic exposure risk from chlorpyrifos in rice grain was 5.90% and 1.30% ADI from field and laboratory results respectively. Concerning the acute dietary exposure, intake estimated for the highest chlorpyrifos level did not exceed the acute reference dose (ARfD = 0.1 mg/kg bw). The estimated short-term intakes (ESTIs) were 0.78% and 0.25% of the ARfD for chlorpyrifos. The results showed that the use of chlorpyrifos in rice paddies was fairly safe for consumption of rice grain by consumers. 相似文献