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中国南方土壤对酸沉降的敏感性   总被引:16,自引:0,他引:16  
在综合考虑我国南方土壤和土壤资料特点的基础上,基于Klopatek的敏感性分类体系,建立了适合我国南方土壤的敏感性分类体系,并用其对南方土壤的敏感性进行了评价。此外也根据土壤盐基含量分析了南方土壤的缓冲能力。  相似文献   

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The combined fouling during ultrafiltration(UF) of surface water pretreated to different extents was investigated to disclose the roles of polysaccharides, proteins, and inorganic particles in UF membrane fouling. Both reversible and irreversible fouling decreased with enhanced pretreatment(biologically active carbon(BAC) treatment and sand filtration). The sand filter effluent fouled the membrane very slowly. The UF membrane removed turbidity to less than 0.1 nephelometric turbidity unit(NTU), reduced polysaccharides by 25.4%–29.9%, but rejected few proteins. Both polysaccharides and inorganic particles were detected on the fouled membranes, but inorganic particles could be effectively removed by backwashing. The increase of turbidity in the sand filter effluent to 3.05 NTU did not significantly increase the fouling rate, but an increase in the turbidity in the BAC effluent to6.11 NTU increased the fouling rate by more than 100%. The results demonstrated that the polysaccharide, not the protein, constituents of biopolymers were responsible for membrane fouling. Membrane fouling was closely associated with a small fraction of polysaccharides in the feed water. Inorganic particles exacerbated membrane fouling only when the concentration of fouling–inducing polysaccharides in the feed water was relatively high. The combined fouling was largely reversible, and polysaccharides were the predominant substances responsible for irreversible fouling.  相似文献   

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The effects of adding a bulking agent and chemically pretreating municipal kitchen waste before aerobic composting were studied using a laboratory-scale system. The system used 20-L reactors and each test lasted 28 days. The objective was to decrease NH3 and H2S emissions during composting. The bulking agent, dry cornstalks, was mixed with the kitchen waste to give a mixture containing 15% (wet weight) bulking agent. A combined treatment was also conducted, in which kitchen waste mixed with the bulking agent was pretreated with ferric chloride (FeCl3). Less leachate was produced by the composted kitchen waste mixed with bulking agent than by the kitchen waste alone, when the materials had reached the required maturity. The presence of cornstalks also caused less H2S to be emitted, but had little impact on the amount of NH3 emitted. The FeCl3 was found to act as an effective chemical flocculant, and its presence significantly decreased the amounts of NH3 and H2S emitted. Kitchen waste mixed with cornstalks and treated with FeCl3 emitted 42% less NH3 and 76% less H2S during composting than did pure kitchen waste.  相似文献   

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运用不同鱼种的急性毒性试验对东北三省具有代表性的化工行业中五种企业污染源排放口水样进行监测,按照工业废水试验方法(鱼类的急性毒性测试)研究了化工废水对于敏感鱼毒性效应。研究结果表明:化工行业废水对不同鱼种均有一定的毒性,随着实际废水暴露浓度的增加,鱼死亡率呈明显的上升趋势,且呈现一定的梯度。同一浓度不同企业的水样,鱼的存活率不同,但有一定的抑制现象。在选取的化工行业中,以不同鱼种作为受试生物的生物毒性大小排序为:吉化1〉吉化2〉吉化3〉吉化4〉吉化5。  相似文献   

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IntroductionNitrousoxide (N2 O)isagreenhousegas.IncreasingatmosphericN2 Oconcentrationmayalsobedetrimentaltothestratosphericozonelayer(Crutzen ,1981) .AgriculturalsoilisamajorsourceofN2 O .MostN2 Ooriginateswithsoilprocesses,asanintermediateproductfrommic…  相似文献   

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Ozone sensitivity was investigated using CAMx simulations and photochemical indicator ratios at three sites (Pingtung City, Chao- Chou Town, and Kenting Town) in Pingtung County in southern Taiwan during 2003 and 2004. The CAMx simulations compared fairly well with the hourly concentrations of ozone. Simulation results also showed that Pingtung City was mainly a volatile organic compounds (VOC)-sensitive regime, while Chao-Chou Town was either a VOC-sensitive or a NOx-sensitive regime, depending on the seasons. Measurements of three photochemical indicators (H2O2, HNO3, and NOy) were conducted, and simulated three transition ranges of H2O2/HNO3 (0.5–0.8), O3/HNO3 (10.3–16.2) and O3/NOy (5.7–10.8) were adopted to assess the ozone sensitive regime at the three sites. The results indicated that the three transition ranges yield consistent results with CAMx simulations at most times at Pingtung City. However, both VOC-sensitive and NOx-sensitive regimes were important at the rural site Chao-Chou Town. Kenting Town, a touring site at the southern end of Taiwan, was predominated by a NOx-sensitive regime in four seasons.  相似文献   

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一直以来植物都是多领域的研究重点,随着非传统稳定同位素的不断发展,植物非传统稳定同位素研究日益增加。但因植物样品中有机物含量高,同位素分馏复杂,样品前处理及测定中存在诸多难题。本文对植物样品非传统稳定同位素工作中常用的前处理方法和测定技术进行了总结。综述了直接萃取法、湿法消解和高温灰化法的原理、操作和优缺点;以K、Ca、Mg、Fe、B等典型非传统稳定同位素为例介绍了非传统稳定同位素常用测定技术,旨在为植物样品的非传统稳定同位素测定进行梳理,最后对其应用方向和测试方法的发展方向进行了展望。  相似文献   

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借助湖泊系统模拟可定量地追踪滇池水质的变化过程,而模型输入水质参数和边界条件对机理模型的结果有显著的影响.然而,目前研究主要关注参数或边界条件对模拟结果的敏感性影响,缺乏兼顾模型内部方程参数与外部输入边界条件对结果的影响,并对比分析其相对大小.以滇池为例,通过对其构建的IWIND水质模型中的90个水体参数、83个底泥参数、6个气象边界条件、51个河流输入边界条件进行联合采样,计算叶绿素a、总氮、总磷、氨氮以及溶解氧5种指标的对数纳什系数(现状为基线),并进行Sobol全局敏感性分析,获得滇池的敏感性参数和边界条件.结果表明:通过比较两大类输入数据的全局敏感性,气象边界条件敏感性最大,其次是水体参数、底泥参数,河流输入边界条件敏感性最小.其中气象敏感边界条件是风速、气压、气温、相对湿度、辐射且风速敏感性最大,水体敏感水质参数主要是藻类代谢及生长过程、碳循环碳矿化过程、氧循环复氧过程与温度相关的参数(KTG2d、TRc;KTMNL;KTR),惰性颗粒态有机物沉降速率(WSrp).底泥敏感参数主要是第二层泥沙浓度(rM2)、底泥中有机碳降解过程中温度相关系数(ThKC1)、惰性颗粒态有机碳转...  相似文献   

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Biowaste valorization through anaerobic digestion is an attractive option to achieve both climate protection goals and renewable energy production.In this paper,a complete set of batch trials was carried out on kitchen waste to investigate the effects of mild thermal pretreatment,temperature regimen and substrate/inoculum ratio.Thermal pretreatment was effective in the solubilisation of macromolecular fractions,particularly carbohydrates.The ability of the theoretical methodologies in estimating...  相似文献   

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碳氮比对稻草和猪粪生物处理及厌氧消化的影响   总被引:2,自引:0,他引:2  
以农业废弃物稻草和猪粪为发酵原料,首次采用纤维素降解复合菌系对稻草和猪粪混合物进行生物处理,通过考察不同碳氮比(25∶1、30∶1、35∶1和40∶1)条件下稻草和猪粪混合物生物预处理的发酵特征及后续的产甲烷能力,探讨了碳氮比对稻草和猪粪的协同生物预处理及厌氧消化效果的影响.结果表明,控制碳氮比为30∶1、料水比为11%时,稻草和猪粪混合物经纤维素降解复合菌系于55℃预处理30 h后其厌氧消化效果最佳.在此条件下,稻草和猪粪降解液中滤纸酶活和羧甲基纤维素酶酶活分别达到了2.18和2.31 IU,其失重率高达41.69%;随后经厌氧发酵后其甲烷产率和产甲烷速率分别可达318.14 m L·g-1(以VS计)和10.61 m L·d-1·g-1(以VS计),且总量为9.9 g的稻草和猪粪混合物的总甲烷产量可达1948 m L,上述结果相对于未经生物预处理的对照组均提高了38%.本研究结果可进一步为其它种类的农作物秸秆和畜禽粪便的高效资源化利用提供理论支撑,展现出了巨大的应用潜力.  相似文献   

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结合某化工企业产生的工业废水在实际处理过程中的实验分析,浅谈一下内电解法(电化学还原)和电催化氧化法(电化学氧化)在污水预处理中的应用和发展.  相似文献   

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Previous studies have reported that triclosan (TCS) could possess an androgenic activity. We aimed to investigate the effects of TCS on gonadal differentiation and development in the frog Pelophylax nigromaculatus, a sensitive amphibian species to androgenic chemicals. P. nigromaculatus tadpoles at stage 24 were exposed to TCS (3, 30, and 300 nmol/L) to stage 46 in a semi-static exposure system. At the end of exposure, gonadal morphology and histology, sex ratio and gonadal expression of sex-biased genes were examined in P. nigromaculatus. In each TCS treatment group, we found several individuals whose gonads exhibited morphological and/or histological abnormalities. Gonadal histological abnormalities were characterized by few oocytes and many somatic cells. Although the percentage of the individuals with abnormal gonads was low (7.8%) among all animals treated with TCS, statistical test revealed the sex ratios in the 3 and 300 nmol/L TCS treatment groups were significantly different from the solvent control. In the 30 nmol/L TCS treatment group, abnormal gonads were also observed, although the sex ratio was not changed compared with the solvent control, which was possibly due to the smaller sample size in this group. In all the TCS treatment groups, the sex ratios were not obviously male-biased, but the expression levels of some sex-biased genes were significantly altered by TCS. Altogether, our results suggest that TCS, even at environmentally relevant concentrations, could disrupt gonadal differentiation and development in P. nigromaculatus, but we are not sure whether the disrupting effects were associated with masculinization or feminization.  相似文献   

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利用合成的NIPAAm-AAc温敏性线型共聚研究了其对无机金属离子的吸附性能,以期应用于水污染的治理,结果表明其有明显的浓度效果,在PH=4时,对Y^3+,Er^3+和UO^2+2的浓集率分别达到84%、65%和56%,相应的浓集量分别为11.2mg.g^-1,4.45mg.g^-1和11.3mg.g^-1,并讨论了影响浓集的条件和吸附机理。  相似文献   

16.
In this study, we conducted an observation experiment from May 1 to June 30, 2018 in Zhengzhou, a major city in central China, where ground ozone (O3) pollution has become serious in recent years. The concentrations of O3 and its precursors, as well as H2O2 and meteorological data were obtained from the urban site (Yanchang, YC), suburban (Zhengzhou University, ZZU) and background sites (Ganglishuiku, GLSK). Result showed that the rates of O3 concentration exceeded Chinese National Air Quality Standard Grade II (93.3 ppbv) were 59.0%, 52.5%, and 55.7% at the above three sites with good consistency, respectively, indicating that O3 pollution is a regional problem in Zhengzhou. The daily peak O3 appeared at 15:00–16:00, which was opposite to VOCs, NOx, and CO and consistent with H2O2. The exhaustive statistical analysis of meteorological factors and chemical effects on O3 formation at YC was advanced. The high concentration of precursors, high temperature, low relative humidity, and moderately high wind speed together with the wind direction dominated by south and southeast wind contribute to urban O3 episodes in Zhengzhou. O3 formation analysis showed that reactive alkenes such as isoprene and cis-2-butene contributed most to O3 formation. The VOCs/NOx ratio and smog production model were used to determine O3-VOC-NOx sensitivity. The O3 formation in Zhengzhou during early summer was mainly under VOC-limited and transition regions alternately, which implies that the simultaneous emission reduction of alkenes and NOx is effective in reducing O3 pollution in Zhengzhou.  相似文献   

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应用物种敏感性分布评估DDT和林丹对淡水生物的生态风险   总被引:22,自引:6,他引:16  
介绍了利用物种敏感性分布(SSD)进行生态风险评价的原理与步骤,构建了淡水生物对DDT和林丹的物种敏感性分布.在此基础上,计算了DDT和林丹对不同类别生物的HC5(Hazardous Concentration for 5% the species)阈值,预测了不同浓度DDT和林丹对生物可能造成的危害,并比较了不同类别生物对DDT和林丹的敏感性,以及DDT和林丹对淡水生物的生态风险.结果表明,DDT和林丹对淡水生物的HC5值分别为1.70μg·L-1和5.96μg·L-1 ,DDT对生态系统的危害大于林丹.当DDT或林丹的浓度为5μg·L-1时,对生态系统仅有轻微影响,而当DDT或林丹的浓度为500μg·L-1时,将有81.5%的物种受到DDT的危害,或有68.1%的物种受到林丹的危害.不同类别生物对DDT的敏感性从甲壳类、昆虫和蜘蛛类到鱼类依次降低,对林丹的敏感性大小依次为昆虫和蜘蛛类、甲壳类、鱼类.与林丹相比,DDT对淡水脊椎动物与无脊椎动物以及甲壳类和鱼类的生态风险较大,而对昆虫和蜘蛛类,林丹与DDT的生态风险差别不大.  相似文献   

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利用发光菌毒性测试技术,研究了5种重金属化合物HgCl2、Pb(NO3)2、Cd(NO3)2、K2Cr2O7、NaAsO2对3种常见发光菌种——青海弧菌Q67、明亮发光杆菌502、费氏弧菌的毒性效应差异.同时,对发光抑制率和金属化合物浓度进行线性回归分析后计算了EC50值(半数效应浓度值),并对比了不同菌种对各金属化合物的敏感度差异及特点.结果表明,5种重金属对青海弧菌Q67的毒性大小顺序为HgCl2Cd(NO3)2NaAsO2Pb(NO3)2K2 Cr2 O7;对明亮发光杆菌502的毒性大小顺序为:HgCl2NaAsO2Pb(NO3)2Cd(NO3)2K2 Cr2 O7;对费氏弧菌的毒性大小顺序为:HgCl2Pb(NO3)2Cd(NO3)2NaAsO2K2Cr2O7.研究结果对利用发光菌毒性测试技术测定不同废水污染时菌种的选择具有指导作用,在未知污染物的情况下应选用几种菌种同时检测,这样可以保证检测结果的可靠性.  相似文献   

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The responses of Sorghum bicolor seedlings, ranging from 3 to 24 days old, to SO2 and NO2, singly and in mixtures, were measured. When applied singly at 100 p.p.b., the pollutants significantly decreased all aspects of growth of the youngest group; the older seedlings were more tolerant. In contrast, the oldest seedlings were the most sensitive to mixtures of SO2 and NO2. When assessing the effects of different concentrations of SO2, it was found that growth was decreased by 45 p.p.b.  相似文献   

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