Patterns of subsidence in the lower Yangtze Delta of China: the case of the Suzhou-Wuxi-Changzhou Region

Investigation indicates that the subsidence pattern in the lower Yangtze Delta area is related to groundwater extraction. Suzhou-Wuxi-Changzhou region ("Su-Xi-Chang") belongs to the hinterland of the lower Yangtze Delta that has a total area of 12,000 km2. From 1979 to 2000, long-term pumping of groundwater at Su-Xi-Chang has caused a rapid decline in groundwater table, resulting in large-scale land subsidence. In this paper, establishment of a GPS-based monitoring system for land subsidence using 30 years of data, is presented. The data were obtained through monitoring of 184 wells. Also analyzed herein is the relationship between the observed lowering of the groundwater table and subsidence. Monitoring data indicate that the depression cone of groundwater table and the occurrence of subsidence are basically identical in time and space. The generation of both features is attributed to excessive extraction of ground water in the region. Finally, countermeasures against subsidence are proposed.     

Effects of hydraulic retention time on net present value and performance in a membrane bioreactor treating antibiotic production wastewater

• The membrane bioreactor cost decreased by 38.2% by decreasing HRT from 72 h to 36 h. • Capital and operation costs contributed 62.1% and 37.9% to decreased costs. • The membrane bioreactor is 32.6% cheaper than the oxidation ditch for treatment. • The effluent COD also improved from 709.93±62.75 mg/L to 280±17.32 mg/L. • Further treatment also benefited from lower pretreatment investment. A cost sensitivity analysis was performed for an industrial membrane bioreactor to quantify the effects of hydraulic retention times and related operational parameters on cost. Different hydraulic retention times (72–24 h) were subjected to a flat-sheet membrane bioreactor updated from an existing 72 h oxidation ditch treating antibiotic production wastewater. Field experimental data from the membrane bioreactor, both full-scale (500 m³/d) and pilot (1.0 m³/d), were used to calculate the net present value (NPV), incorporating both capital expenditure (CAPEX) and operating expenditure. The results showed that the tank cost was estimated above membrane cost in the membrane bioreactor. The decreased hydraulic retention time from 72 to 36 h reduced the NPV by 38.2%, where capital expenditure contributed 24.2% more than operational expenditure. Tank construction cost was decisive in determining the net present value contributed 62.1% to the capital expenditure. The membrane bioreactor has the advantage of a longer lifespan flat-sheet membrane, while flux decline was tolerable. The antibiotics decreased to 1.87±0.33 mg/L in the MBR effluent. The upgrade to the membrane bioreactor also benefited further treatments by 10.1%–44.7% lower direct investment.     

Empirical analysis of carbon tariff’s effect on the export structure of China’s manufacturing industry and social welfare based on the GTAP model

In recent years, carbon emissions have gradually evolved from an environment issue into a political and economic one. Carbon tariff has brought about new trade barriers of developed countries, and in order to enhance the industrial competitiveness of developed countries, it will produce unfavorable impact on developing countries. Concentrated on the manufacturing industry, which is the most intensive high-carbon industry in China’s export structure, this article studies the relationship between carbon tariff policy and industry structure of export trade and builds up a relation between climate change and international trade. First, by means of establishing a partial equilibrium model, it applies geometric analysis and mathematical analysis to compute the impact on China’s manufacturing export trade and the consequences of the introduction of the US carbon tariff to China’s manufacturing industry that has already imposed a domestic shipping carbon tax. Furthermore, with the application of the GTAP model, it estimates the overall economic and welfare effects on China’s manufacturing industry if the US and Europe introduce carbon tariff by means of four ways, and then analyzes the influence on China’s manufacturing industry export structure and social welfare as well. The result shows that the introduction of the US carbon import tariff lowers China’s export price and export volume, and the implementation of a domestic carbon tax justifies a higher export price and a lower export volume for China. However, the degree of export reduction is smaller than that under the effect of the US carbon tariff. In the case of developed countries imposing carbon tariff on China’s energy-intensive industries, such as chemical rubber products, oil and coal-processing industry and paper industry, whose export would be reduced, the negative impact on the paper industry is the severest, which will decrease the paper industry’s export ranging from 1.79% to 6.05%, whereas the other industries’ export will increase. Anyhow, it will promote China’s manufacturing industry to adjust the export structure to a certain extent. In addition, it will lead to a decrease in China’s welfare, with a decrease between $2.134 billion and $8.347 billion. Finally, this paper provides information on international coordination, export structure adjustment and green manufacturing adjustment as a reference for the development of China’s manufacturing industry.     

一种台风灾情综合评估模型及应用

对台风灾情评估提出了一种基于台风灾害案例历史案例分析、综合模糊数学和灰色关联分析的综合评估模型;利用模糊隶属函数将台风灾情原始数据无量纲化,再设定一极重灾为参考序列。根据台风各评估指标与参考序列的距离,计算出关联系数;将关联系数加权平均和定义为灾度,根据灾度值评定台风的灾级。并以广东省台风灾情为例,验证了此模型。     

污水湿地处理工程水力停留时间的测定

利用ＵＡＰ对一个湿地处理工程的实际水力停留时间进行了测定,进而对相关问题进行了探讨。     

Perchlorate removal using granular activated carbon supported iron compounds: Synthesis, characterization and reactivity

Synthesis and use of the iron compounds supported on granular activated carbon (ICs/GAC) have shown significant environmental implications for perchlorate (ClO 4 ) removal. ICs/GAC was synthesized via hydrolyzing FeSO 4 ·7H 2 O on GAC, reduced by NaBH 4 solution in polyethylene glycol 6000 and ethanol solution, dried in vacuum condition and exposed to air. Synthesized ICs/GAC was characterized using transmission electron micrograph (TEM), Brunauer-Emmett-Teller, X-ray photoelectron spectroscopy (XPS). ICs/GAC was determined to be containing a large amount of FeOHSO 4 , Fe 2 O 3 and a small amount of zero-valent iron (ZVI) nanoparticles according to TEM and XPS measurements. Batch static kinetic tests showed that 97% of ClO 4 was removed within 10 hr at 90°C and 86% of ClO 4 was removed within 12 hr at 25°C, at ICs/GAC dosage of 20 g/L. The experimental results also showed that FeOHSO 4 and Fe 2 O 3 nanoparticles have the function of perchlorate adsorption and play important roles in ClO 4 removal. The activation energy (E a ) was determined to be 9.56 kJ/mol.     

环境—经济系统能值（Emergy）评价：介绍Odum的能值理论

介绍了美国著名生态学家Ｈ．Ｔ．Ｏｄｕｍ创立的能值理论，通过具体实例来分析环境－ 能值特征，评价环境征税的经济价值，阐明自然环境与人类经济相互协调发 的重要性，为人们正确评价环境和从事科研提供新思路。     

基于ASM2D模拟的双流态UNITANK改进工艺的设计与实验分析

针对传统UNITANK污泥浓度不稳定、低负荷释磷不充分以及池体容积比例不合理等不足,提出了改进工艺:双流态UNITANK;利用ASM2D模型对改进工艺进行模拟分析,并通过实验对其进行了验证。结果表明,基于ASM2D的模拟是有效的,双流态UNITANK有效克服了传统UNITANK存在的不足。     

低氨氮废水亚硝化的快速启动

以低氨氮废水为研究对象,研究了亚硝化反应的快速启动,通过对比实验考察了羟胺(NH_2OH)和肼(N_2H_4)投加对氨氧化与亚硝酸盐氧化反应的影响。结果表明:NH_2OH的投加更有利低氨氮废水亚硝化反应的实现;在此基础上,通过序批式运行模式,在每周期开始时投加NH_2OH(2 mg·L~(-1)),研究了低氨氮废水亚硝化反应的快速启动;通过9 d的驯化,亚硝酸盐积累率可达到100%,AOB与NOB丰度比升高至25,有利于亚硝化启动的实现。研究结果可为低氨氮废水亚硝化反应快速启动提供技术支持。     

“路怒症”的内外生逻辑及影响因素研究

为探索“路怒症”的内外生逻辑，运用调查问卷数据，采用灰色关联分析法从即时和长期2方面对引发路怒的原因进行分析。结果表明:在引发路怒的即时原因中，前车或其他车随意变换车道或调头、其他车辆插队或加塞、夜间行驶开远光灯是最重要的3个原因；在引发路怒的长期原因中，工作或生活压力大最易引发路怒。运用Logistic回归分析各主要路怒原因的易发驾驶人群，据此提出针对性建议，以促进城市交通安全有效治理。