地埋式污水处理装置初探

简述了地埋式污水处理装置在工程设计和工程应用中实际情况,比较分析了有动力和无动力地埋式污水处理装置各自的优缺点,提出了应根据工程实际情况选择相应类型污水处理装置的建议.     

Research on carbon emissions in China's export trade based on input-output model

Becoming the world’s largest emitter of carbon makes China the object of criticism;however,people may ignore the fact that when China exports low-carbon products,the carbon emissions have been left in the meanwhile,forming the so-called"embodied carbon".Using the input-output model,this paper analyzes the carbon emission intensity and amount of embodied carbon of various sectors in China’s export trade in 2002 and 2007,and filters out high carbon emission sectors.In addition,this paper also points out the problem of carbon emissions’international transfer from developed countries to China through the analysis of national and regional flow of export carbon emissions and changing of the proportion of emissions for exports relative to total emissions,and explains the reason that caused carbon transfer to China by using the treadmill of production theory.Based on that,this paper proposes some measures for carbon reduction in China from the foreign trade perspective.     

Impact of Covid-19 partial lockdown on PM2.5, SO2, NO2, O3, and trace elements in PM2.5 in Hanoi,Vietnam

Covid-19 lockdowns have improved the ambient air quality across the world via reduced air pollutant levels. This article aims to investigate the effect of the partial lockdown on the main ambient air pollutants and their elemental concentrations bound to PM_2.5 in Hanoi. In addition to the PM_2.5 samples collected at three urban sites in Hanoi, the daily PM_2.5, NO₂, O₃, and SO₂ levels were collected from the automatic ambient air quality monitoring station at Nguyen Van Cu street to analyze the pollution level before (March 10th–March 31st) and during the partial lockdown (April 1st–April 22nd) with “current” data obtained in 2020 and “historical” data obtained in 2014, 2016, and 2017. The results showed that NO₂, PM_2.5, O₃, and SO₂ concentrations obtained from the automatic ambient air quality monitoring station were reduced by 75.8, 55.9, 21.4, and 60.7%, respectively, compared with historical data. Besides, the concentration of PM_2.5 at sampling sites declined by 41.8% during the partial lockdown. Furthermore, there was a drastic negative relationship between the boundary layer height (BLH) and the daily mean PM_2.5 in Hanoi. The concentrations of Cd, Se, As, Sr, Ba, Cu, Mn, Pb, K, Zn, Ca, Al, and Mg during the partial lockdown were lower than those before the partial lockdown. The results of enrichment factor (EF) values and principal component analysis (PCA) concluded that trace elements in PM_2.5 before the partial lockdown were more affected by industrial activities than those during the partial lockdown.

     

Characteristics and Bioactivities of Carrageenan/Chitosan Microparticles Loading α-Mangostin

Journal of Polymers and the Environment - This study attempted to develop carrageenan/chitosan based microparticles loading α-mangostin which was extracted from Vietnamese mangosteen skin. The...     

邻苯二甲酸酯类对水生食物链的影响研究进展

邻苯二甲酸酯类(PAEs)增塑剂被普遍用于塑料制品中,在大气、水等环境中广泛存在,其潜在危害受到关注。水环境中的PAEs,从藻类等初级生产者吸收,到浮游动物、游泳动物等通过鳃和皮肤直接接触或捕食摄取,在水生生物之间转化和传递。笔者总结了PAEs在水生食物链中不同营养级生物体的含量,分析了PAEs在食物链中富集和转化的影响因素(辛醇-水分配系数Kow、代谢转化、生长阶段等)。目前的研究表明PAEs可能在食物链中传递,最终在较高营养级生物体中富集。同时总结了5种PAEs(邻苯二甲酸二丁酯、邻苯二甲酸二乙酯、邻苯二甲酯丁苄酯、邻苯二甲酸二(2-乙基)己酯和邻苯二甲酸二甲酯)对水生生物的毒性效应的研究进展,已有研究表明PAEs对藻类的细胞器和抗氧化体系,对鱼类的生殖系统、内分泌系统和抗氧化体系都有一定程度损伤。PAEs在食物链中传递和富集现象的存在会对高营养级水生生物产生潜在危害。针对目前PAEs在食物链中传递的研究数量较少、结构简单等问题,对未来研究方向做了简要分析和展望。     

Dissipation of polycyclic aromatic hydrocarbons and microbial activity in a field soil planted with perennial ryegrass

Dissipation and plant uptake of polycyclic aromatic hydrocarbons (PAHs) in contaminated agricultural soil planted with perennial ryegrass were investigated in a field experiment. After two seasons of grass cultivation the mean concentration of 12 PAHs in soil decreased by 23.4% compared with the initial soil. The 3-, 4-, 5-, and 6-ring PAHs were dissipated by 30.9%, 25.5%, 21.2%, and 16.3% from the soil, respectively. Ryegrass shoots accumulated about 280 μg·kg^-1, shoot dry matter biomass reached 2.48 × 10⁴ kg·ha^-1, and plant uptake accounted for about 0.99% of the decrease in PAHs in the soil. Significantly higher soil enzyme activities and microbial community functional diversity were observed in planted soil than that in the unplanted control. The results suggest that planting ryegrass may promote the dissipation of PAHs in long-term contaminated agricultural soil, and plant-promoted microbial degradation may be a main mechanism of phytoremediation.     

诺氟沙星对土壤微生物碳代谢功能多样性的影响

为了解诺氟沙星在环境中的残留对土壤微生物的影响,借助BIOLOG法对诺氟沙星作用下土壤微生物的碳源利用及代谢功能多样性进行了研究.研究发现,用药后d 7、d 21、d 35,用药组(诺氟沙星含量1μg g-1、10μg g-1、100μgg-1)BIOLOG微平板上平均每孔颜色变化率(Average well color development,AWCD)均低于对照组;用药d 7,1μg g-1、10μg g-1、100μg g-1组土壤微生物丰富度指数与多样性指数显著低于(P<0.05)对照组,d 21,10μg g-1、100μg g-1组与对照组差异显著,d 35仅100μg g-1组与对照组差异显著.结果表明,诺氟沙星影响了土壤微生物群落的碳代谢功能,包括代谢强度和代谢多样性,但不同浓度的诺氟沙星对土壤微生物群落代谢功能的影响也不相同.100μg g-1的诺氟沙星在用药的前期和后期均显著影响土壤微生物群落的碳代谢功能,土壤中诺氟沙星积累到该浓度可能对土壤微生物群落碳代谢功能产生难以逆转的长期影响.     

影响短程硝化反硝化的因素

短程硝化反硝化是指将硝化过程控制在亚硝化阶段,随后在缺氧条件下进行反硝化的生物脱氮过程,其关键是如何控制硝化过程中影响HNO2积累的因素,分析影响HNO2积累因素,包括温度、游离氨、pH值、溶解氧、有害物质和泥龄,探讨实现短程硝化反硝化的途径。     

长期定位施肥下紫色土土壤微形态特征

通过对紫色土长期定位施肥下不同施肥处理0～20 cm耕层土壤微形态特征的研究,试图说明施肥对紫色土微形态的影响.用单偏光显微镜对不同处理的土壤微形态进行了观察与分析.结果表明:长期不施肥料的CK处理,土壤耕层结构致密,很少有孔隙发育,土壤微结构为结构较差的碎屑聚积状-沙粒聚积状;长期单施化学肥料,土壤颗粒未形成结构体,少孔隙,土壤微结构主要为斑晶胶凝状-细沙粒聚积状结构,土壤结构比CK处理优;长期施用有机肥或有机无机肥料配施的处理,土壤粗颗粒数量显著增加,结构疏松,孔隙量大,动、植物残体丰富,有铁锰结核和腐殖质的形成和微团聚体的发育,土壤微结构类型以MNPK处理最好,为胶凝紧实状-多孔状结构.有机无机肥料配施能显著改良紫色土的结构,培肥土壤,实现土壤可持续发展.