A method to extract algae toxin of microcystin-LR

A simple and low-cost method to obtain cyanobacterial toxin microcystin-LR(MC-LR) was developed. A new strain of Microcystis aeruginosa,named DC-1, producing microcystin-LR but not microcystin-RR, was separated from the field blooming algae samples of Dianchi Lake.in southwest of China. Following three times‘freeze and thaw treatment, the cultivated DC-cells were extracted with 40% methanol in water.The extract was centrifuged and the supernatant applied to a Hydrophilic-Lipophilic Balance(HLB) SPE cartridge.Eluted impuries with a certain gradient from 30% to 50% methanol in water, MC-LR was finally eluted from the HLB cartridge with 60%.may be used in adsorption and biodegradation experiments instead of using expensive standard reagents.     

Hybrid zeolite-based ion-exchange and sulfur oxidizing denitrification for advanced slaughterhouse wastewater treatment

The discharge of slau ghterhouse wastewater（SWW） is incre asing and its wastewater has to be treated thoroughly to avoid the eutrophication.The hybrid zeolite-based ion-exchange and sulfur autotrophic denitrification（IX-AD） process was developed to advanced treat SWW after traditional secondary biological process.Compared with traditional sulfur oxidizing denitrification（SOD）,this study found that IX-AD column showed:（1） stronger ability to resist NO₃^-pollution load,（2） low...     

几种印染助剂对壳聚糖稳定纳米铁去除酸性品红的影响

以氯化铁为铁源,硼氢化钠为还原剂,壳聚糖为稳定剂,采用液相还原法制备壳聚糖稳定纳米铁（CS-nZⅥ）;研究了印染废水中常见助剂NaNO₃、Na₂SO₄、NaH₂PO₄、K₂Cr₂O₇、EDTA二钠盐存在下,超声波辅助CS-nZⅥ对酸性品红（AF）降解的影响。结果表明,反应15 min,0.01 g CS-nZⅥ对25 mL、100 mg/L AF的去除率高达99.9%;各种助剂的存在使得纳米铁表面不同程度失活,阻碍反应的进行,使得AF的去除率下降。NaNO₃、K₂Cr₂O₇、EDTA二钠盐与纳米铁发生反应,与AF存在明显的竞争作用。重复利用实验表明,CS-nZⅥ重复利用7次仍具有一定的反应活性。此外,CS-nZⅥ对加标（50 mg/L）实际废水中AF的去除率达到99%以上,表明CS-nZⅥ是一种潜在的环境修复材料。     

Bipolar charged aerosol agglomeration and collection by a two-zone agglomerator

ＩｎｔｒｏｄｕｃｔｉｏｎＢｅｃａｕｓｅｏｆｔｈｅｌｏｗｅｆｆｉｃｉｅｎｃｙｏｆｔｈｅｅｌｅｃｔｒｏｓｔａｔｉｃｐｒｅｃｉｐｉｔａｔｏｒ (ＥＳＰ)ｆｏｒｃｏｌｌｅｃｔｉｎｇｔｈｅｓｕｂｍｉｃｒｏｎｐａｒｔｉｃｌｅｓ ,ｔｈｅｅｌｅｃｔｒｉｃａｌａｇｇｌｏｍｅｒａｔｉｏｎｍｅｔｈｏｄｈａｓｌｅｄｔｏａｎｉｎｃｒｅａｓｉｎｇｉｎｔｅｒｅｓｔｉｎｒｅｄｕｃｉｎｇｔｈｅｅｍｉｓｓｉｏｎｏｆｔｈｅｆｉｎｅｐａｒｔｉｃｌｅｓ .Ｍａｎｙａｕｔｈｏｒｓｈａｖｅｓｔｕｄｉｅｄｅｌｅｃｔｒｉｃａｌａｇｇｌｏｍｅｒａｔｉ…     

江西省耕地土壤氮素空间变异特征及其影响因素

为定量探讨省域尺度下土壤氮素空间变异特征及其影响因素。以江西省2012年测土配方施肥项目采集的16 582个耕地表层(0~20 cm)土壤样点数据,运用普通克里格、单因素方差分析与回归分析方法,对土壤氮素空间变异特征及其影响因素进行分析。结果表明：（1）江西省土壤全氮(TN)含量在026~375 g/kg之间,平均值为158 g/kg,变异系数为3101%;碱解氮(AN)含量值域范围为1160~39970 mg/kg,平均值为16431 mg/kg,变异系数为3460%;二者均呈中等程度的变异性。（2）经半方差分析,TN与AN的变程分别为31489和3030 km,TN的空间自相关范围大而AN较小。（3）在空间分布上,高值区主要分布在新余市、抚州市与景德镇市。（4）回归分析与单因素方差分析结果表明,地形因子、耕地利用方式、成土母质、土壤类型和秸秆还田方式对土壤氮素空间变异影响极显著(P<001)。秸秆还田方式对土壤TN与AN空间变异的独立解释能力最高,分别为271%与42%,是影响江西土壤氮素空间变异的主要因素。     

Forecasting China’s primary energy demand based on an improved AI model

An improved energy demand forecasting model is built based on the autoregressive distributed lag (ARDL) bounds testing approach and an adaptive genetic algorithm (AGA) to obtain credible energy demand forecasting results. The ARDL bounds analysis is first employed to select the appropriate input variables of the energy demand model. After the existence of a cointegration relationship in the model is confirmed, the AGA is then employed to optimize the coefficients of both linear and quadratic forms with gross domestic product, economic structure, urbanization, and technological progress as the input variables. On the basis of historical annual data from 1985 to 2015, the simulation results indicate that the proposed model has greater accuracy and reliability than conventional optimization methods. The predicted results of the proposed model also demonstrate that China will demand approximately 4.9, 5.6, and 6.1 billion standard tons of coal equivalent in 2020, 2025, and 2030, respectively.     

Effects of Topographical Heterogeneity and Dispersal Limitation on Species Turnover in a Temperate Mountane Ecosystem: a Case Study in the Henan Province,China

Species turnover patterns can be inconsistent due to differences in the dispersal ability of different growth forms. Here, species of trees, shrubs, herbs, and bryophytes in the Xiaoqinling National Nature Reserve in China were analyzed to determine patterns of species turnover along an elevation and spatial gradient. Variance partitioning was used to assess the relative contribution of topographic heterogeneity and dispersal limitation to species turnover. Our results suggest that the effect of dispersal limitation is more important than topographic heterogeneity on species turnover in temperate mountane ecosystems in the study area. Dispersal limitation has a greater effect on trees species turnover than on shrubs, herbs or bryophytes species turnover.     

Effects of Na+ on Cu/SAPO-34 for ammonia selective catalytic reduction

Copper-exchanged chabazite (Cu/CHA) catalysts have been found to be affected by alkali metal and alkaline earth ions. However, the effects of Na⁺ ions on Cu/SAPO-34 for ammonia selective catalytic reduction (NH₃-SCR) are still unclear. In order to investigate the mechanism, five samples with various Na contents were synthesized and characterized. It was observed that the introduced Na⁺ ion-exchanges with H⁺ and Cu^2 + of Cu/SAPO-34. The exchange of H⁺ is easier than that of isolated Cu^2 +. The exchanged Cu^2 + ions aggregate and form “CuAl₂O₄-like” species. The NH₃-SCR activity of Cu/SAPO-34 decreases with increasing Na content, and the loss of isolated Cu^2 + and acid sites is responsible for the activity loss.     

混凝-Fenton-BAF深度处理垃圾渗滤液中试研究

针对经过SBR处理后,难以再进一步生化降解的垃圾渗滤液,提出混凝-Fenton-曝气生物滤池(BAF)工艺进行深度处理.首先利用混凝去除SBR出水的悬浮性有机物,降低Fenton试剂的处理成本;然后采用Fenton试剂进行氧化处理,既降低垃圾渗滤液的COD值,又提高其可生化性,最后通过BAF工艺去除有机物,实验结果表明,在SBR出水COD为600～800 mg/L的情况下,最终出水的COD低于80 mg/L,处理成本仅为2.6元/t.     

中亚与我国西北地区环境蠕变问题的分析

讨论了中亚和我国西北地区环境蠕变问题,分析了环境蠕变与人类活动,环境蠕变与气候变化的关系.结果表明,在近年全球增暖的背景下,由于人类过度开采和利用水资源,引起了环境进一步恶化;气候变暖加速了环境恶化的进程.干旱、半干旱地区,生态脆弱,当人类活动超过自然承载力时,小的气候波动也可能引起大的环境变化.