pH敏感性β-环糊精微球的制备及其吸附性能

采用反相微悬浮乳液聚合技术制备了β-环糊精(β-CD)微球,用丁二酸酐对β-CD微球进行化学改性,制备了pH敏感性β-CD(pH-β-CD)微球.通过傅里叶红外光谱仪和扫描电子显微镜对微球的结构、粒径和形貌进行了表征.探讨了亚甲基蓝模拟染料废水pH、吸附时间和微球加入量对亚甲基蓝吸附性能的影响.实验结果表明,在亚甲基蓝模拟染料废水pH为10.0、吸附时间为90 min的条件下,当pH-β-CD微球加入量为50 mg时,pH-β-CD微球吸附量为16.1 mg/g;当pH-β-CD微球加入量为250 mg时,pH-β-CD微球对亚甲基蓝的脱色率达96.2%.     

5—(4—磺酸基苯偶氮)8—(2,4—二硝基苯氨基)喹啉测定食品中铜的研究应用

在弱碱性介质中 ,5— (4—磺酸基苯偶氮 ) 8— (2 ,4—二硝基苯氨基 )喹啉 (SPDNPAQ)与铜反应生成 2∶ 1紫红色络合物 ,体系 λmax=56 0 nm,ε=1.2 3× 10 5L· mol-1· cm-1。铜含量在 0～ 0 .4 mg/ L内符合比耳定律 ,方法用于一些生物样品和水样中铜的测定。     

Performance evaluation of a full-scale natural treatment system for nonpoint source and point source pollution removal

This study presents a full-scale performance of a natural treatment system (NTS) facility in Taiwan with nearly 2 years of observations. The study site, composed of several treatment ponds in series, was designed primarily to reduce polluted stormwater runoff from tea gardens and partially to untreated domestic wastewater from nearby villages. Thus, both nonpoint source and point source pollution are treated in this system. From 28 field samplings in 2006-2007, the NTS site shows satisfactory treatment performance and the effluent water quality is significantly improved. Seven of the 28 sampling events are storm events (nonpoint source pollution) and the remainder are from regular monitoring (point source pollution). The average volume of influent and effluent is 533 CMD and 196 CMD, respectively. In order to determine the removal efficiency, several assessment measures are employed in an attempt to obtain unbiased conclusions. They are removal rate (RR), efficiency rate (ER), summation of loads (SOL), flux rate (FR), and effluent probability method (EPM). The average percent removal efficiency of NH(3)-N is 53.5-75.2% and of TP is 59.0-84.7%, in which the highest result is calculated by SOL method and the lowest rate is obtained from RR. In FR evaluation, larger treatment capacity for NH(3)-N than for TP is provided in the site and the average FR is respectively 0.230 g/m(2) day and 0.017 g/m(2) day. Of the methods examined, EPM is the only method capable of illustrating data distribution. Finally, recommendations on the usefulness of these measures are summarized to facilitate the understandings of NTS performance evaluations.     

Disinfection by-product formation and mutagenic assay caused by preozonation of groundwater containing bromide

Brominated organic and inorganic by-products are generated during ozonation of groundwater containing high bromide concentrations. This study measured concentrations of bromate, bromoform, bromoacetic acids, bromoacetonitriles, bromoacetone, 2,4-dibromophenol and aldehyde generated by ozonation. The potential mutagenicity of ozonated waters was assessed using the Ames and Microtox tests. Test results for the 18 ozonated groundwater samples demonstrate that bromate formation is associated with high pH, bromide and alkalinity content, low levels of dissolved organic carbon (DOC) and ammonia, and low alkalinity. Brominated organic by-products were correlated with high bromide ion and natural organic matter content, and low ammonia concentrations. The Ames test results demonstrate that all extracts from ozonated water have mutagenic activity; however, the 18 raw groundwater samples had no mutagenicity. The Microtox test results also show that the ozonated water samples were highly toxic. Generally, both bromide and DOC content promoted the formation of ozonation by-products and mutagenicity. Controlling of bromide and DOC concentrations is an effective method of reducing potential by-product formation and eliminating mutagenicity problems associated with groundwater ozonation.     

IFTCIP: An Integrated Optimization Model for Environmental Management under Uncertainty

In this study, an interval-fuzzy two-stage chance-constrained integer programming (IFTCIP) method is developed for supporting environmental management under uncertainty. The IFTCIP improves upon the existing interval, fuzzy, and two-stage programming approaches by allowing uncertainties expressed as probability distributions, fuzzy sets, and discrete intervals to be directly incorporated within a general mixed integer linear programming framework. It has advantages in uncertainty reflection, policy investigation, risk assessment, and capacity-expansion analysis in comparison to the other optimization methods. Moreover, it can help examine the risk of violating system constraints and the associated consequences. The developed method is applied to the planning for facility expansion and waste-flow allocation within a municipal solid waste management system. Violations of capacity constraints are allowed under a range of significance levels, which reflects tradeoffs between the system cost and the constraint-violation risk. The results indicate that reasonable solutions for both binary and continuous variables have been generated under different risk levels. They are useful for generating desired decision alternatives with minimized system cost and constraint-violation risk under various environmental, economic, and system-reliability conditions. Generally, willingness to take a higher risk of constraint violation will guarantee a lower system cost; a strong desire to acquire a lower risk will run into a higher system cost.     

双三角解析法快速配制环境监测分析中的标准溶液

介绍了在环境监测分析中精确配制一定浓度标准溶液的快速方法。利用双三角解析法称量标准物质和配制标准溶液,实验过程快速、准确。在环境监测分析应用中取得较好效果,不确定度无显著差异。     

Behaviour of selected endocrine-disrupting chemicals in three sewage treatment plants of Beijing, China

Occurrence and fate of eight kinds of selected endocrine-disrupting compounds (EDCs) in three sewage treatment plants (STPs) of Beijing, China was investigated. These EDCs, composed of 4-octylphenol (4-OP), 4-n-nonylphenol (4-n-NP), bisphenol A (BPA), estrone (E1), 17α-estradiol (17α-E2), 17β-estradiol (E2), estriol (E3) and 17α-ethinylestradiol (EE2), in every step of STPs, were simultaneously analysed by gas chromatography/mass spectrometry after derivatisation. All the EDCs were detected in the influents of three STPs, and BPA was the most abundant compound. The concentrations of EDCs ranged from 36.6 ng/l of 17α-E2 (STP C) to 1342.3 ng/l of BPA (STP B) in the influent sewages and from below limits of detection of E2 and E3 (STP C) to 142.5 ng/l of E1 (STP B) in the effluent sewages. The STPs could not remove alkylphenols effectively from the aqueous phase with less than 40% reduction. BPA decreased over 90%, and steroid estrogens achieved considerable reductions from 64.8% of E2 to 94.9% of E3. Generally, biological treatment was more effective in removing alkylphenols, BPA and natural estrogens from the aqueous phase than primary treatment. However, the synthetic estrogen, EE2, was mostly removed by the primary treatment with about 63.5% reduction. It is the first time that the concentration of 17α-E2 in the sewage of China was reported in this paper. The compound might have a bearing with the waste effluents of dairy farms around urban area of Beijing.     

Survey of heavy metal pollution and assessment of agricultural soil in Yangzhong district, Jiangsu Province, China

We investigated concentrations of Hg, Cd, Pb, Zn, Cu, As, Ni, and Cr in samples of soil, cereal, and vegetables from Yangzhong district, China. Compared to subsoils, the sampled topsoils are enriched in Hg, Cd, Cu, Pb, Zn, and As. High levels of Cd and Hg are observed in most agricultural soils. Concentrations of Cr and Ni show little spatial variation, and high Cu, Pb, and Zn contents correspond well to areas of urban development. High As contents are primarily recorded at the two ends of the sampled alluvion. The contents of Cd, Hg, and total organic carbon (TOC) increase gradually to maximum values in the upper parts of soil profiles, while Cr and Ni occur in low concentrations within sampled profiles. As, Pb, Cu, and Zn show patterns of slight enrichment within the surface layer. Compared to data obtained in 1990, Cd and Hg show increased concentrations in 2005; this is attributed to the long-term use of agrochemicals. Cr and Ni contents remained steady over this interval because they are derived from the weathering of parent material and subsequent pedogenesis. The measured As, Cu, Pb, and Zn contents show slight increases over time due to atmospheric deposition of material sourced from urban anthropogenic activity. Low concentrations of heavy metals are recorded in vegetables and cereals because the subalkaline environment of the soil limits their mobility. Although the heavy metal concentrations measured in this study do not pose a serious health risk, they do affect the quality of agricultural products.     

Investigation of a new approach to decompose two potent greenhouse gases: photoreduction of SF(6) and SF(5)CF(3) in the presence of acetone

In this paper, we addressed the utilization of photochemical method as an innovative technology for the destruction and removal of two potent greenhouse gases, SF(6) and SF(5)CF(3). The destruction and removal efficiency (DRE) of the process was determined as a function of excitation wavelength, irradiation time, initial ratio of acetone to SF(5)X (X represented F or CF(3)), initial SF(5)X concentration, additive oxygen and water vapor concentration. A complete removal was achieved by a radiation period of 55min and 120min for SF(6)-CH(3)COCH(3) system and SF(5)CF(3)-CH(3)COCH(3) system respectively under 184.9nm irradiation. Extra addition of water vapor can enhance DRE by approximately 6% points in both systems. Further studies with GC/MS and FT-IR proved that no hazardous products such as S(2)F(10), SO(2)F(2), SOF(2), SOF(4) were generated in this process.     

Influence of metal ion on sorption of p-nitrophenol onto sediment in the presence of cetylpyridinium chloride

Heavy metals and surfactants have a significant effect on the sorption of organic contaminants. In this study, batch equilibrium experiments were carried out to investigate the influence of Pb(NO(3))(2) on the sorption of p-nitrophenol (PNP) onto sediments in the presence of cationic surfactant cetylpyridinium chloride (CPC). Results indicated that in the complex system containing PNP, Pb(NO(3))(2) and CPC, the sorption of PNP decreased with increasing concentration of Pb(NO(3))(2) due primarily to competing for adsorption sites. Likewise, partitioning of PNP in adsorbed surfactant layers and micelles decreased with increasing level of Pb(NO(3))(2). Moreover, the influence of different metal ions (Pb(2+), Cd(2+), Zn(2+)) was examined and results indicated that the presence of heavy metals inhibited the sorption of PNP in the order: Pb(2+)>Cd(2+)>Zn(2+). The competitive effect of the heavy metals was in agreement with the hydration energy and hydrated radius. The results are believed to provide a useful insight into describing the transport and fate of PNP in natural environments.