Characterization of Dust Storms to Hong Kong in April 1998

In April 1998, two intense dust storms were generated in CentralAsia and transported eastward across East Asia (15 and 19 April). This article presents the chemical characterization ofHong Kong (HK) aerosols during the dust storms. During the 15 Aprildust storm, hourly respiratory suspended particles (RSP)(particle diameter smaller than 10 m) concentrationsmonitored at 7 sites in Hong Kong reached the peak valuessynchronously between 9 and 11 a.m. on 17 April, in which thehighest concentration was 267 g m^-3. Analysis ofthe RSP samples showed that concentrations of crustalelements (Ba, Ca, Cd, Cr, Fe, Mg, K⁺) and anthropogenicspecies (As, Ni, Pb, Zn, NH₄ ⁺, NO₃ ^-,SO₄ ^2- and total carbon) were substantiallyenhanced. Enhancement of these species was more than afactor of 2 to 14 relative to the non dust period. The totalcarbon content was high, at 59 g m^-3 (notincluding carbonate), and the enrichment factors of Asand Pb on 17 April were 122 and 117, respectively. Thisimplied that anthropogenic materials together with mineraldust were transported to HK from Mainland China. Based onmaterial balance calculations, mineral dust contributed41% to the observed RSP mass on 17 April, which was 2 times thatof the nondust sample (22%). From the 5-day backwardtrajectory analysis, this storm was transported directlyfrom Northwest China to HK. However, there was nocorresponding observation for the 19 April dust stormaerosol. Consequently, 15 April storm had stronger impact onHK's atmosphere than 19 April storm. Compared to the HK AirQuality Objective, 15 April dust storm did not cause seriousair pollution in HK.     

吸烟气相物质引起的脂质过氧化的研究

本文用吸烟气相物质作用于卵磷脂形成的脂质体及人多形核白细胞,用TBA法和共轭二烯法检测吸烟气相物质作用下的脂质过氧化水平,结果发现,随着吸烟气相物质作用时间的延长,MDA和共轭二烯的含量也随之增大。表明吸烟气相物质能够引起脂质过氧化反应。     

南亚热带丘陵土壤水分循环及其有效性的研究──Ⅵ.丘陵赤红壤-果树-大气连续体中能量的变化及其分布规律

依据田间实测资料,分析了南亚热带丘陵赤红壤-果树-大气连续体中的能量变化及其分布规律、结果表明,土壤基质势的年度变化特征说明南亚热带丘陵赤红壤存在明显的湿季和旱季．果树叶水势随土壤基质势、大气水势、气温及大气相对湿度的变化而变化,荔枝、龙眼叶水势的变化比芒果叶水势的变化大.以荔枝、芒果和龙眼作为供试植物,水分从土壤到达植物根表皮、进入根系并通过植物茎到达叶片,其能量降低分别约为0．9063～1.7428、0．2818～0．6979和0．2904～1．8707MPa;水分从叶部汽化扩散到大气中,其能量降低分别达15．1491～57．3669、15．4491～58．4036和14．5824～56．9536MPa,说明水流在南亚热带丘陵赤红壤-果树-大气连续体中运移时,其能量主要消耗在由叶部到大气这一环节上。     

灰色关联分析中分辨系数的确定方法

通过实例计算表明，在进行灰色关联分析时，分辨系数的变化将导致关联度的变化而影响关联序。从最大信息量和最大信息分辨率出发，给出了确定分辨系数的计算公式。     

Influence of filtration velocity on DON variation in BAF for micropolluted surface water treatment

Biological aerated filters (BAFs) are widely used for the treatment of micropolluted surface water. However, the biological process produces dissolved organic nitrogen (DON), which, as precursors of nitrogenous disinfection by-products, pose potential threats to drinking water safety. Therefore, to control DON in BAF effluent, it is necessary to study the influence of BAF operation parameters on DON production. In this study, the influence of filtration velocity in a BAF on DON production was investigated. Under different filtration velocity (0.5, 2, and 4 m/h) conditions, profiles of DON concentrations along the media layer were measured. The profile at a filtration velocity of 0.5 m/h showed a decreasing trend, and the ones under filtration velocities of 2 and 4 m/h fluctuated in a small range (from 0.1 to 0.4 mg/L). Moreover, the relatively high filtration velocities of 2 and 4 m/h resulted in a lower level of DON concentration. Additionally, 3D excitation-emission matrix fluorescence spectroscopy was used to characterize DON. It is found that the patterns of DON at a relatively high filtration velocity condition (4 m/h) were obviously different from the ones under low filtration velocity conditions (0.5 and 2 m/h).     

China’s Import of Wastes and Its Implications

Abstract

The trade of wastes in the world has been increasing and China has become the largest importer of wastes. This paper examines the import trend of different wastes and finds out that the total import volume to China approved by the Chinese government keeps increasing and the illegal trade can not be banned despite repeated prohibitions; therefore, China is not only “a world factory”, but actually “a global garbage dump”. In order to well understand the implications of wastes import, this paper further analyzes the resource and environmental effects and risks of different wastes imports as well as the strong driving force of wastes imports. Based on these detailed analysis and solid data, policy recommendations are put forward to reduce the demand for raw materials, to further strengthen the inspection of and supervision over the international trade of the wastes that can be used as raw materials by using the life cycle analysis and risk analysis, to improve the environmental standards and strengthen the disposal capacity, to re-export the raw materials produced from the imported wastes, to develop the long-term planning for the import of wastes and to promote international cooperation.     

Effect of multiple washing operations on the removal of potentially toxic metals from an alkaline farmland soil and the strategy for agricultural reuse

Few studies have carried out soil washing experiments using pot experiments to simulate in situ soil washing operations, particularly for alkaline soils. This study explored the effects of multiple washing operations using pot experiments on the removal efficiencies of potentially toxic metals (PTM) from alkaline farmland soil and the reuse strategy of washed soil for safe agricultural production. The results showed that the removal efficiencies of Cd, Pb, Cu, and Zn after seven washings with a mixed chelator (EDTA, GLDA, and citric acid) were 41.1%, 47.1%, 14.7%, and 26.5%, respectively, which was close to the results of the EDTA treatment. For the alkaline soil studied, the second washing with the mixed chelators most effectively removed PTM owing to the activation of them after the first washing operation. The mixed chelator more effectively increased the proportion of stable fraction of PTM and maintained soil nutrients (e.g., nitrogen content) than EDTA, indicating little disturbance of alkaline soil quality after washing with the mixed chelator. After the amendment of the washed soil, there was no visible difference in the biomass weight of crops from the soils washed with different agents, indicating that the inhibitory effect of both washing agents on plant growth was effectively alleviated. The Cd and Pb contents in Z. mays were below the threshold of Hygienical Standard for Feeds of China (GB 13078–2017) (1 and 30 mg·kg^?1). Moreover, after three cropping operations, the available concentrations of PTM in the soil washed with the mixed chelator were lower than those in the soil washed with EDTA, indicating the value and potential of agricultural reuse of alkaline farmland soil washed with the mixed chelator.

Graphical abstract

     

硫酸铜和马度米星铵联合暴露对鲫鱼的毒性和效应标记物研究

为探究硫酸铜和马度米星铵对水产动物的生态毒性,本研究以鲫鱼为模型,从急性毒性、亚急性毒性和遗传毒性3个方面研究硫酸铜和马度米星铵单一与联合暴露对鲫鱼的毒性效应.结果 表明,硫酸铜对鲫鱼96 h的半数致死浓度(50％ lethal concentration,LC50)为3.6 mg·L-1,硫酸铜和马度米星铵联合暴露时...     

成都市城市环境与经济协调发展分析

从城市环境与经济发展的协调度方面分析了成都市１９９０－１９９７年间协调度的变化趋势,评估了成都市城市环境与经济协调发展的类型,得出了成都市属于总体协调发展类环境滞后型的结论。     

Environmental knowledge,behaviors, and attitudes regarding caffeine consumption among Chinese university students from the perspective of ecopharmacovigilance

Environmental Science and Pollution Research - Caffeine is considered the most representative pharmaceutical emerging contaminant (PEC) because of its ubiquity, high environmental abundance,...