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121.
Environmental Science and Pollution Research - With the development of industry, sustainable use of natural resources has become a worldwide hot topic. Heavy metal–containing sludge (HMS) is...  相似文献   
122.
Environmental Science and Pollution Research - Groundwater resource is significantly important for sustainable development of the world, especially for arid endorheic watersheds. A total of 28...  相似文献   
123.
Environmental Science and Pollution Research - The failure of the centralized water supply system forced XY community to become more dependent on uncertain and unstable water sources. The results...  相似文献   
124.

Surface sediments were collected from 122 sites in the upstream of the Yellow River, China. The concentration of Fe, Mn, Cu, Ni, Zn, Cr, Pb, and Cd in sediments was investigated to explore the spatial distribution based on statistics and interpolation method. The results suggested that the concentrations of heavy metals were lower than potential effect levels (PEL). The samples above threshold effect level (TEL) for Pb and Zn were less than 10%, while almost 50% of samples for Ni exceeded PEL. Pb and Zn in sediments performed little or no adverse effects on the aquatic ecosystems. Higher concentrations of all heavy metals occurred in Qinghai and Gansu sections; the concentrations of Cu, Ni, and Zn were significantly higher than the Inner Mongolia section. Lower concentration of Fe, Mn, Cu, Ni, and Zn appeared in Qinghai section; the concentrations of Fe, Mn, Cr, and Pb manifested relatively steady and similar distributions and approximately decreasing tendency along the upstream of Yellow River.

  相似文献   
125.
Environmental Science and Pollution Research - Light absorption enhancement of black carbon due to the aerosol mixing states is an important parameterization for climate modeling, while emission...  相似文献   
126.
中国西南酸雨区降水化学特征研究进展   总被引:10,自引:3,他引:7  
周晓得  徐志方  刘文景  武瑶  赵童  蒋浩 《环境科学》2017,38(10):4438-4446
西南酸雨区为我国主要酸雨沉降区,且是全球三大喀斯特集中分布区之一.本文将该区9个地点的降雨资料进行了总结、整理和分析,数据包括pH值和主离子成分(Cl~-、SO_4~(2-)、NO_3~-、Ca~(2+)、NH_4~+、Mg~(2+)、K~+、Na~+).该地区降雨中的主要阴离子为SO_4~(2-)和NO_3~-,主要阳离子为Ca~(2+)和NH_4~+.与我国其它地区相比,其酸性离子、碱性离子和总离子浓度均普遍高于东南地区、而低于我国北方地区.西南酸雨区主要以pH值为4.5~5.6的弱酸性降雨为主,占总降雨频次的58%左右.根据酸、碱性离子的相关性、中和因子等分析结果,该区雨水中的酸性物质可能受到了碱性离子的中和作用,其中起主要中和作用的离子为Ca~(2+)和NH_4~+.将该区雨水pH值和酸、碱性离子浓度与我国其它地区进行对比研究发现,西南酸雨区降雨受到的中和作用要强于东南地区,但弱于北方地区的降雨.通过对西南酸雨区降雨中主要离子来源的分析和估算,降雨中的酸性离子SO_4~(2-)和NO_3~-主要来自于人为污染;99.7%的Ca~(2+)和84.0%的Mg~(2+)为陆源贡献,这可能与西南地区碳酸盐岩广泛分布有关.  相似文献   
127.
为了解新乡市地表水中HCHs和DDTs的分布特征及生态风险,采集新乡市18个地表水样并测定其中HCHs和DDTs的含量,采用概率密度函数重叠面积法和安全阈值法评价了HCHs和DDTs的生态风险.结果表明,新乡市地表水中HCHs和DDTs的质量浓度范围分别为1.28~49.2 ng·L-1和0.42~12.3 ng·L-1,与世界各地的地表水中HCHs和DDTs残留质量浓度相比属于中等污染水平.异构体比值表明HCHs污染的主要来源是林丹的使用,而DDTs的残留来源于工业品DDTs的使用.生态风险评价基于DDD、γ-HCHs和p,p'-DDT的暴露浓度以及相应的毒性数据,概率密度函数重叠面积法和安全阈值法均表明了这3种有机氯农药中DDD的风险最大,其次是γ-HCHs,p,p'-DDT的生态风险最小;安全阈值法进一步表明DDD、γ-HCHs和p,p'-DDT超过影响10%水生生物的概率分别为10.2%、5.94%和0.01%.  相似文献   
128.
Sulfamethoxypyridazine(SMP) is one of the commonly used sulfonamide antibiotics(SAs).SAs are mainly studied to undergo triplet-sensitized photodegradation in water under natural sunlight with other coexisting aquatic environmental organic pollutants.In this work,SMP was selected as a representative of SAs.We studied the mechanisms of triplet-sensitized photodegradation of SMP and the influence of selected dissolved inorganic matter,i.e.,anions(Br~-,Cl~-,and NO~-_3) and cations ions(Ca~(2+),Mg~(2+),and Zn~(2+)) on SMP photodegradation mechanism by quantum chemical methods.In addition,the degradation mechanisms of SMP by hydroxyl radical(OH·) were also investigated.The creation of SO_2 extrusion product was accessed with two different energy pathways(pathway-1 and pathway-2) by following two steps(step-I and step-II) in the tripletsensitized photodegradation of SMP.Due to low activation energy,the pathway-1 was considered as the main pathway to obtain SO_2 extrusion product.Step-II of pathway-1 was measured to be the rate-limiting step(RLS) of SMP photodegradation mechanism and the effect of the selected anions and cations was estimated for this step.All selected anions and cations promoted photodegradation of SMP by dropping the activation energy of pathway-1.The estimated low activation energies of different degradation pathways of SMP with OH·radical indicate that OH·radical is a very powerful oxidizing agent for SMP degradation via attack through benzene derivative and pyridazine derivative ring.  相似文献   
129.
The relationship between the fine particles emitted after desulfurization and gypsum crystals in the desulfurization slurry was investigated, and the crystallization characteristics varying with the operation parameters and compositions of the desulfurization slurry were discussed. The results showed that the fine particles generated during the desulfurization process were closely related to the crystal characteristics in the desulfurization slurry by comparison of their morphology and elements. With the higher proportion of fine crystals in the desulfurization slurry, the number concentration of fine particles after desulfurization was increased and their particle sizes were smaller, indicating that the optimization of gypsum crystallization was beneficial for the reduction of the fine particle emission. The lower pH value and an optimal temperature of the desulfurization slurry were beneficial to restrain the generation of fine crystals in the desulfurization slurry. In addition, the higher concentrations of the Fe3 + ions and the F ions in the desulfurization slurry both promoted the generation of fine crystals with corresponding change of the morphology and the effect of the Fe3 + ions was more obvious. With the application of the desulfurization synergist additive, it was beneficial for the inhibition of fine crystals while the thinner crystals were generated.  相似文献   
130.
针对煤制烯烃项目废水的来源及水质特点,从生化处理技术与回用处理技术方面阐述了煤制烯烃废水处理现状及存在问题,展望了煤制烯烃废水处理与回用技术未来发展方向,指出了新型脱氮工艺、膜集成工艺及分质结晶技术在煤制烯烃废水处理中的可行性,为煤化工废水处理与资源化利用提供理论参考。  相似文献   
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