南京市不同功能区PM10中多环芳烃的污染特征

PM10是衡量大气环境质量好坏的重要指标之一;多环芳烃(PAHs)是具有强烈致癌性的有机污染物,大多吸附在粒径小于10 μm颗粒物上.利用长期定位实验采集了南京市两典型功能区--大厂地区和山西路的PM10样品,对其PAHs质量浓度进行了分析测定,研究了不同功能区PM10中PAHs的时空污染特性.研究结果表明:南京市PM10污染比较严重,其质量浓度变化范围在0.1157 mg·m-3～0.3913 mg·m-3之间;经分析PM10中16种优控多环芳烃(PAHs)发现,全年大厂地区的PAHs的质量浓度与山西路PAHs的质量浓度没有明显的高低之分;PAHs总质量浓度的空间变化不明显,时间变化也没有规律性;比较PM10与PAHs的月平均质量浓度变化趋势,两者之间的变化没有相关性,各自的质量浓度变化也没有规律性,分析其结果可能是由于PAHs的不稳定性造成的.     

生物炭基调理剂对水稻镉吸收的影响

以木质生物炭为基础,与沸石、石灰石、磷酸钙等混配制生物炭基调理剂,并用于镉污染稻田。通过田间水稻栽培实验,探讨该生物炭基调理剂的合适配比及应用效果。按照DTPA浸提法分析土壤中有效态镉含量,按HNO3-HCLO4消化法测定水稻植株中镉的含量。结果表明：随木炭用量增加,土壤中有效态镉减少,施用0.48 kg·m-2木炭时降幅高达23.87%。施用不同配比炭基调理剂实验中,木炭:石灰石:沸石:磷酸钙=4:1:1:1时对土壤中有效态镉的钝化效果最好,达到36.42%。水稻根、茎累积镉量高于叶、壳、糙米,并且稻米中镉含量与栽培后期50 d土壤中有效态镉含量高度相关,相关系数为0.921 6（P<0.05）。     

Flocculation performance of epichlorohydrin-dimethylamine polyamine in treating dyeing wastewater

Epichlorohydrin-dimethylamine polymers with different intrinsic viscosity (η) and cationicity (τ) were synthesized. The flocculation performance and mechanism of these polymers in the removal of the reactive and disperse dyes from synthetic wastewater was investigated in terms of flocculation dynamics and color removal efficiency. The polymer flocculation efficiency was compared with that of polyaluminum chloride (PAC) and a composite flocculant based on polyaluminum chloride-epichlorohydrin-dimethylamine polyamine. The results showed that epichlorohydrin-dimethylamine polymer was effective over a pH range of 2–10 for the reactive and disperse dye removal (Reactive Brilliant Red and Disperse Yellow dyes). Epichlorohydrin-dimethylamine polymer with the highest η and τ gave the best reactive dye removal efficiency, and its adsorption-bridging and electric neutralization ability played important roles in the flocculation process. The higher the η viscosity of the epichlorohydrin-dimethylamine polymer, the better the flocculation performance of epichlorohydrin-dimethylamine polyamine, and stronger adsorption-bridging ability was obtained for removing the disperse dye from dyeing wastewaters. Epichlorohydrin-dimethylamine polymer achieved better decolorization performance when used together with PAC.     

我国北方风沙灾害加剧的成因及其发展趋势

综合分析了我国风沙灾害加剧的原因,并从我国北方沙漠、沙地形成演变的地理格局,探讨了我国沙化过程的中、长期发展趋势。本文认为,我国近年风沙灾害的加剧是在气候趋于干燥化背景下,人类大面积发展沙区生产的结果,但是,目前的流沙分布范围仍不及末次冰期极盛时期。未来我国风沙灾害的发展主要取决于气候增温背景下降水的时空分布、沙区的风化变化与地表土地的利用格局。     

基于溶解度参数的计算检测沉积物中微塑料

目前,密度分离法广泛应用于各种环境介质中微塑料的提取.为了进一步准确测量沉积物中微塑料的质量浓度,本研究开发了一种基于溶解度参数(δ)计算的选择性检测方法,建立了加速溶剂萃取(ASE)-微塑料选择性析出-傅里叶变换红外光谱仪(FTIR)检测的技术路线.6种微塑料[聚丙烯(PP)、聚乙烯(PE)、聚苯乙烯(PS)、聚碳酸...     

Leaching and degradation of ethametsulfuron-methyl in soil

Leaching and degradation of the herbicide ethametsulfuron-methyl[methyl 2-[(4-ethoxy-6-methylamino-1,3,5-triazine-2-yl)carbamoylsulfamoyl]benzoate] in three soils were investigated under laboratory conditions. Ethametsulfuron-methyl was mobile on soils when tested using non-aged and aged soil columns; this mobility agreed reasonably well with Freundlich soil isotherm constants. It was found that ethametsulfuron-methyl was more mobile in alkaline sandy Vertisol soil and neutral loamy Alfisol soil than in acidic clayey Red soil. Degradation of ethametsulfuron-methyl in soils was pH-dependent; calculated half-life (t(1/2)) values ranged from 13 to 67 days. Ethametsulfuron-methyl was more persistent in neutral or weakly basic than in acidic soil. Five soil metabolites were isolated and identified by LC/MS/MS analysis. The degradation pathways included the cleavage of the sulfonylurea bridge, N- and O-dealkylation, and triazine ring opening.     

海藻酸钠微胶囊负载纳米铁吸附水中的As(Ⅴ)

利用本实验所制备的海藻酸钠微胶囊负载纳米零价铁材料(M-NZVI)对水中不同浓度的As(V)进行了吸附去除研究,并比较了不同材料的吸附等温曲线。实验结果表明,2 g/L M-NZVI在pH=6.5±0.1,常温常压条件下对5 mg/L的As(V)的吸附去除率为90.35%,吸附速率较快,在30 min即可达到吸附平衡。通过M-NZVI、Ca-ALG和NZVI的热力学对比实验可知,M-NZVI表现出优越的吸附性能。溶液吸附剂添加量、初始pH值、离子浓度等因素对M-NZVI吸附水中砷离子的效率有一定影响:在其他条件不变的情况下,As(V)的去除率随着添加量的增加而逐渐增大;M-NZVI对As(V)的最佳吸附效果在pH=6~7范围之间;溶液中高浓度NaCl能对M-NZVI的吸附性产生较强的干扰。同时,对于As(V) ≤ 5 mg/L的溶液,M-NZVI可以不做任何处理多次利用3~4次。这些结果显示,M-NZVI是一种用于原位修复重金属污染水体的潜在理想材料。     

Preparation of spherical iron nanoclusters in ethanol-water solution for nitrate removal

In this study, a higher surface area spherical nanoscale zero valent iron (HNZVI) cluster (80 nm, 54.25 m(2)g(-1)) was synthesized in ethanol-water mixed solvent in the presence of dispersion agent of polyglycol (PEG). At the same time, a lower surface area nanoscale zero valent iron (LNZVI) particle (80 nm, 8.08 m(2)g(-1)) was also prepared with only de-ioned water as reaction media. Their structures, compositions and physical properties were characterized by transmission electron microscope (TEM), X-ray diffractometer (XRD), inductively coupled plasma atomic emission spectrophotometer (ICP-AES), and Brunauer-Emmett-Teller (BET) surface area analyzer and the results obtained for these two kinds of nanoscale iron were compared with each other and also with those reported in the literatures. The HNZVI clusters seemed to be accumulated by smaller iron particles (<10 nm). At the same time, whiskers were formed in the final produce. Reactivity of the HNZVI was affirmed via denitrification of nitrate. The factors controlling the reduction of nitrate, such as pH, dissolved oxygen (DO), iron content as well as the initial nitrate concentration were also discussed. Finally, kinetic analysis revealed that chemical reduction of nitrate by HNZVI could not be described by the first- or pseudo-first-order kinetic model.     

Brominated flame retardants in the hair and serum samples from an e-waste recycling area in southeastern China: the possibility of using hair for biomonitoring

Hair samples and paired serum samples were collected from e-waste and urban areas in Wenling of Zhejiang Province, China. The PBDE and DBDPE concentrations in hair and serum samples from e-waste workers were significantly higher than those of non-occupational residents and urban residents. BDE209 was the dominating BFRs in hair and serum samples from the e-waste area, while DBDPE was the major BFRs from the urban area. Statistically significant correlations were observed between hair level and serum level for some substances (BDE209, DBDPE, BDE99, BDE47, BDE28, and BDE17), although the PBDE congener profiles in hair were different from those in the serum. A statistically significant positive correlation between the PBDE concentrations and the working age, as well as gender difference, was observed in e-waste workers. Different sources of PBDEs and DBDPE in three groups were identified by principal component analysis and spearman correlation coefficient. Hair is suggested to be a useful matrix for biomonitoring the PBDE exposure in humans.     

Metagenomic assessment of the microbial diversity in ground pork products from markets in the North Central Region of South Korea

The purpose of this study was to characterize the microbial community in ground pork using molecular approaches. Forty six ground pork products were purchased from local stores in the north central area of South Korea. Aerobic plate counts varied 4.23 ± 5.14 × 10⁵ CFU/g with the range between 5.00 × 10³ and 1.85 × 10⁶ CFU/g for ground pork samples. Four ground meat samples were further processed for metagenomic analysis. Pseudomonas species was the most relative abundant with a wide range occurring (1.72 to 77.7%) as part of the microbial genera in ground pork. Bacteria such as Carnobacterium, Yersinia, Photobacterium were also identified in ground pork. Despite the prominence of certain genera across all samples there was still extensive microbial diversity among ground pork products that originated from different slaughter houses and were processed in different markets. Such diversity indicates that designing interventions to extend shelf life may be hampered by the extensive variability in the microbial consortia associated with pork products. However, this diversity may be useful for developing microbial traceability signatures unique to a slaughter house or a particular market.