Risk Assessment of Carbon Sequestration for Terrestrial Ecosystems in China

Climate change will alter the capacity of carbon sequestration,and the risk assessment of carbon sequestration for terrestrial ecosystems will be helpful to the decision-making for climate change countermeasures and international climate negotiations.Based on the net ecosystem productivity of terrestrial ecosystems simulated by Atmosphere Vegetation Integrated Model,each grid of the risk criterion was set by time series trend analysis.Then the risks of carbon sequestration of terrestrial ecosystems were investigated.The results show that,in the IPCCSRES-B2 climate scenario,climate change will bring risks of carbon sequestration,and the high-risk level will dominate terrestrial ecosystems.The risk would expand with the increase of warming degree.By the end of the long-term of this century,about 60% of the whole country will face the risk;Northwest China,mountainous areas in Northeast China,middle and lower reaches plain of Yangtze River areas,Southwest China and Southeast China tend to be extremely vulnerable.Risk levels in most regions are likely to grow with the increase of warming degree,and this increase will mainly occur during the near-term to mid-term.Northwest China will become an area of high risks,and deciduous coniferous forests,temperate mixed forests and desert grassland tend to be extremely vulnerable.     

Selective removal of diclofenac from contaminated water using molecularly imprinted polymer microspheres

A molecularly imprinted polymer (MIP) was synthesized by precipitation polymerization using diclofenac (DFC) as a template. Binding characteristics of the MIP were evaluated using equilibrium binding experiments. Compared to the non-imprinted polymer (NIP), the MIP showed an outstanding affinity towards DFC in an aqueous solution with a binding site capacity (Q_max) of 324.8 mg/g and a dissociation constant (K_d) of 3.99 mg/L. The feasibility of removing DFC from natural water by the MIP was demonstrated by using river water spiked with DFC. Effects of pH and humic acid on the selectivity and adsorption capacity of MIP were evaluated in detail. MIP had better selectivity and higher adsorption efficiency for DFC as compared to that of powdered activated carbon (PAC). In addition, MIP reusability was demonstrated for at least 12 repeated cycles without significant loss in performance, which is a definite advantage over single-use activated carbon.     

ZnO的制备及其光催化性能

分别采用草酸沉淀法和柠檬酸络合法制备了纤锌矿型ZnO,通过X射线粉末衍射仪、扫描电子显微镜和透射电子显微镜对ZnO的结构和形貌进行了表征,并研究了所制备的ZnO对溶液中甲基橙的光催化降解性能.实验结果表明:草酸沉淀法制备的ZnO为小颗粒堆积而成的空心类柱状体,柠檬酸络合法制备的ZnO为小球形颗粒;草酸沉淀法制备的ZnO...     

表面活性剂洗脱含油污泥中的机油

采用表面活性剂洗脱法去除含油污泥中的机油,考察了4种表面活性剂对含油污泥的洗脱效果.实验结果表明:当以质量浓度为100 mg/L吐温80为洗脱剂、洗脱时间为4h、洗脱温度为25℃、溶液pH为6时,溶液中油质量浓度最大,为1 293.68 mg/L,此时含油污泥中油的洗脱率为86.25％;无机离子的加入总体上减小了表面活...     

一种多DTC基团重金属螯合剂的合成及处理含铜废水性能

合成了一种新的二硫代氨基甲酸盐类重金属螯合剂CDTC,并对其处理游离铜离子、EDTA络合铜和柠檬酸络合铜废水的性能进行了研究.实验结果表明:CDTC能直接去除已络合的铜,对不同形态的Cu2+去除率均达99%以上,处理后的废水中Cu2+剩余浓度达到我国<污水综合排放标准>(GB 8978-1996)一级标准;在废水pH=...     

Research on the effects of command-and-control and market-oriented policy tools on China’s energy conservation and emissions reduction innovation

The impact of environmental regulation on technology innovation is a hot spot in current research where a large number of empirical studies are based on Porter Hypothesis (PH). However, there are still controversies in academia about the establishment of “weak” and “narrow” versions of PH. Based on the panel data of application for patent of energy conservation and emission reduction (ECER) technology of Chinese city scale during 2008–2014, comprehensive energy price, pollutant emission, etc., mixed regression model and systematic generalized method of moments method were adopted, respectively, to study the impact of market-oriented and command-and-control policy tool on China’s ECER technology innovation. The results show that the environmental regulation hindered the technological innovation in the immediate phase; however, it turned out to be positive in the first-lag phase. Hence, the establishment of “weak” PH is time-bounded. The command-and-control policy tool played a more positive role in promoting technological innovation in the first-lag phase than market-oriented policy tool. Therefore, “narrow” PH is not tenable. The reason is that the main participants of China’s ECER technology innovation are state-owned companies and public institutions. Regionally speaking, the impact which command-and-control policy tool has on technological innovation at sight was non-significant in the eastern, the central, and the western regions of China whilst market-oriented policy tool had a negative effect. And market-oriented policy tool in the central region had strongest negative effect, which would diminish in the eastern region and become weakest in the western region. This was related to regional energy consumption level and the market economic vitality.     

Efficient model calibration method based on phase experiments for anaerobic–anoxic/nitrifying (A2N) two-sludge process

A systematic calibration and validation procedure for the complex mechanistic modeling of anaerobic–anoxic/nitrifying (A2N) two-sludge system is needed. An efficient method based on phase experiments, sensitivity analysis, and genetic algorithm is proposed here for model calibration. Phase experiments (anaerobic phosphorus release, aerobic nitrification, and anoxic denitrifying phosphate accumulation) in an A2N sequencing batch reactor (SBR) were performed to reflect the process conditions accurately and improve the model calibration efficiency. The calibrated model was further validated using 30 batch experiments and 3-month dynamic continuous flow (CF) experiments for A2N-SBR and CF-A2N process, respectively. Several statistical criteria were conducted to evaluate the accuracy of model predications, including the average relative deviation (ARD), mean absolute error (MAE), root mean square error (RMSE), and Janus coefficient. Visual comparisons and statistical analyses indicated that the calibrated model could provide accurate predictions for the effluent chemical oxygen demand (COD), ammonia nitrogen (NH₄ ⁺-N), total nitrogen (TN), and total phosphorus (TP), with only one iteration.

     

Nickel stressed responses of rice in Ni subcellular distribution,antioxidant production,and osmolyte accumulation

Environmental Science and Pollution Research - Nickel has been found a key pollutant in farmlands of central and south China, and understanding of Ni toxicity in rice is of great significance in...     

五氯酚(PCP)对鸡肝癌细胞(LMH)毒性效应的机制研究

五氯酚(pentachlorophenol,PCP)是一种持久性有机污染物,广泛用于灭钉螺、木材防腐、除草剂等方面,由于PCP在环境中的持久性和生物累积性,其对生态环境和人类健康造成潜在危害。本文以鸡肝癌细胞系(chicken hepatoma cells,LMH)为受试对象,探讨了PCP对细胞色素P450(CYP450)和抗氧化系统的影响。MTT结果显示LMH细胞经不同浓度PCP暴露后,呈现出先促进细胞增殖后抑制的J-型曲线,PCP对LMH细胞24 h的半数效应浓度(24 h-EC50)为427.52μmol·L~(-1)。LMH细胞在1.56、6.25、25、100μmol·L~(-1)PCP染毒条件下可增加细胞EROD、MROD、PROD和BFC活性,并可使CYP1A、1B、1C、2H及3A家族基因mRNA表达水平升高。LMH细胞在0.4~100μmol·L~(-1)PCP染毒下可显著降低硫酸基转移酶(SULT1B1和SULT 1C1)基因mRNA水平。此外,LMH细胞在6.25、25、100μmol·L~(-1)PCP染毒下可引起细胞内ROS升高,同时PCP(1.56~100μmol·L~(-1))可显著增加细胞内MDA含量和降低GSH/GSSH比值。这些结果表明细胞色素P450(CYP450)基因及酶活性的变化、细胞内ROS和MDA含量及GSH/GSSH可作为评价LMH细胞PCP毒性效应的敏感性生物标志物。此研究在细胞水平上利用多个评价指标研究PCP对细胞的毒性效应,为PCP环境风险评价提供依据。     

Response of sediment calcium and magnesium species to the regional acid deposition in eutrophic Taihu Lake,China

Acid deposition causes carbonate dissolution in watersheds and leads to profound impacts on water chemistry of lakes. Here, we presented a detailed study on the seasonal, spatial, and vertical variations of calcium and magnesium species in the overlying water, interstitial water, and sediment profiles in eutrophic Taihu Lake under the circumstance of regional acid deposition. The result showed that both the acid deposition and biomineralization in Taihu Lake had effects on Ca and Mg species. In the lake water, calcium carbonate was saturated or over-saturated based on long-term statistical calculation of the saturation index (SI). On the sediment profiles, significant difference in Ca and Mg species existed between the surface sediment (0–10 cm) and deeper sediments (>10 cm). The interstitial water Ca²⁺ and Mg²⁺, ion-exchangeable Ca and Mg in the surface sediment were higher than those in the deeper sediment. In the spring, when the acid deposition is more intensive, the acid-extracted Ca and Mg in the surface sediment were lower than that in the deeper sediment in the northwest lake, due to carbonate dissolution caused by the regional acid deposition. Spatially, the higher concentration of acid-extracted Ca and Mg in the northwest surface sediment than that in the east lake was observed, indicating the pronounced carbonate biomineralization by algae bloom in the northwest lake. Statistical analysis showed that acid deposition exerted a stronger impact on the variation of acid-extracted Ca and Mg in the surface sediment than the biomineralization in Taihu Lake. For the total Ca and Mg concentration in the spring, however, no significant change between the surface and deeper sediment in the northwest lake was observed, indicating that the carbonate precipitation via biomineralization and the carbonate dissolution due to acidic deposition were in a dynamic balance. These features are of major importance for the understanding of combined effects of acid deposition and eutrophication on freshwater lakes.