苯并(α)芘与砷在蜈蚣草中的赋存转运规律及其交互作用

蜈蚣草能够超累积土壤中的砷,对土壤环境中的多环芳烃也具有较好的耐受能力,是修复砷和多环芳烃复合污染的理想修复手段之一.为探究在苯并（a）芘和砷（As）单独污染和复合污染条件下的蜈蚣草对两种污染物的吸收转运,通过水培模拟实验揭示蜈蚣草体内砷与苯并（a）芘的交互作用,同时采用双光子激光共聚焦扫描显微技术检测观察苯并（a）芘在蜈蚣草中的赋存和分布.结果表明,添加苯并（a）芘使得蜈蚣草各部分总砷含量均下降.其中,叶、茎、根分别下降149.4、78.59、47.05 mg·kg^-1（以DW计）（p<0.05）,叶部下降幅度最大,达到47.3%,根部及茎部含量分别下降了40.9%和38.2%（p<0.05）.同时苯并（a）芘的添加也改变了砷在蜈蚣草体内的赋存形态,根部与叶部三价砷的比例分别下降了3.87%、4.20%（p<0.05）,而茎部两种砷形态比例无显著变化.砷的添加促进了蜈蚣草各部分对苯并（a）芘的积累,每株根部、茎部和叶部的累积量分别增加了4680、109.26和226.61 ng（p<0.05）,说明苯并（a）芘和砷在蜈蚣草植株中交互作用显著,砷的添加不会改变苯并（a）芘的赋存位点,但会增强蜈蚣草对于苯并（a）芘吸收,而苯并（a）芘的添加则会抑制砷的吸收,苯并（a）芘首先由蜈蚣草根部表皮细胞吸收,通过茎部的U型维管束及茎部外缘细胞转运到叶部,赋存于叶部的表皮细胞、叶脉组织及气孔细胞当中.     

A CLOSED WATER REUSE SYSTEM FOR POWER PLANT COOLING AND DIGESTER HEATING1

ABSTRACT: A model consisting of closed water reuse and productive use of various types of wastes for energy generation is presented. The sewage after treatment would be used as the cooling water for power plants, and the condenser discharge therefrom be used as heating water for sludge digesters. The water is then purified for municipal water supply for continuous use. The advantages of this system are that water resources and energy are conserved while various types of wastes including waste heat are controlled. With a preliminary system analysis, it appears that the design for power plant based on the total heating value of wastes and digester capacity based on sewage sludge generation is feasible in terms of acquisition and full utilization of various types of wastes as generated in a single metropolitan area. The system as shown in this design is in balance among various factors such as the generation rate of municipal refuse, municipal sewage, waste heat in the condenser discharge, and raw sewage sludge.     

Male reproductive biology of the red frog crab,Ranina ranina,off Hachijojima,Izu Islands,Japan

Male red frog crabs, Ranina ranina, were collected year round in 1990 and 1991 off Hachijojima for histological study of the reproductive system and cycle. The testis containing the lobules and seminiferous ducts is surrounded by connective tissue. The seminiferous duct connects to the anterior end of the vas deferens, which can be histologically divided into three portions similar to one another in appearance. It was surrounded by fibrous connective tissue, muscle fibrils and columnar epithelium. Muscle fibrils were absent in the anterior portion. Multiple sperm masses were not formed in the vas deferens and ejaculatory duct, but the sperm mass was covered with a capsule composed of two layers. The outer layer of the capsule was periodic acid Schiff (PAS)-positive, but the inner layer was negative. Both layers were Alcian Blue negative, except the vacuoles in the outer layer that were stained blue. The small round androgenic gland was attached to the posterior end of the vas deferens of the coxa of the eighth thoracic appendage. The ejaculatory duct was distinguishable from the vas deferens by the absence of columnar epithelium and the presence of thick longitudinal muscle fibers. Spermatogenesis was histochemically examined. The acrosomal vesicle appeared to be derived from PAS-positive vesicles in the cytoplasm of the spermatid at the early stage of spermiogenesis. The arms were positive to the Feulgen reaction and the subacrosomal region was negative to PAS. Seasonal changes in reproductive cycle were inconspicuous histologically and microscopically. Sperm were always present in the testis and vas deferens throughout the year and occupied 5.1 to 19.6% of testis observed in cross sections. The minimum size of maturity is less than 39 mm carapace length, but the minimum size capable of successful mating was estimated to be ca. 55 mm.     

A model for pulse jet fabric filters

A new model for pulse jet fabric filtration is proposed. In contrast to the earlier model of Ravin and Humphries, which was formulated on the steady state assumption, the present study is aimed at developing a predictive capability for both transient and steady state operations, taking into account the compression effect of filter cakes. The model's relative simplicity allows frequent updating of the model parameter values, thus improving the accuracy of predictions. As a result, the model is particularly useful in developing control algorithms and designing controllers of pulse jet fabric filtration systems.     

Quantification and modelling of 2,4-dinitrotoluene reduction with high-purity and cast iron

Cast iron has been used as a reactive material in permeable reactive barriers (PRBs) for site remediation. While reactions are generally believed to occur on the iron (oxide) surface, a recent study by [Oh, S.Y., Cha, D.K., Chiu, P.C., 2002a. Graphite-mediated reduction of 2,4-dinitrotoluene with elemental iron. Environ. Sci. Technol. 36 (10), 2178-2184] showed that graphite inclusions in cast iron can also serve as reaction sites for 2,4-dinitrotoluene (DNT). These authors also found that graphite-mediated reduction of DNT has a regioselectivity that is different from that for iron surface. In this study, we quantified the observations reported by Oh et al. and examined the role of graphite in cast iron through numerical modelling. Models containing one and two reaction sites were developed to evaluate the mass transfer, sorption and reaction rates for DNT reduction in batch systems containing high-purity and cast iron. Our simulations showed that the regioselectivity, defined as the ratio of the ortho- and para-nitro reduction rate constants, was 0.37+/-0.04 S.E. (S.E.=one estimated standard error) for iron surface and 3.59+/-0.76 S.E. for graphite surface. In the cast iron-water system, we estimated that at least 66+/-2% S.E. of the DNT was reduced on graphite surface, despite the low graphite content and the lower DNT reduction rate with graphite than with iron. Graphite played such an important role because of the rapid adsorption of DNT to graphite. In the batch experiments conducted by Oh et al., external mass transfer was not rate limiting. Surface reaction was the rate-limiting step for DNT reduction on the graphite surface in cast iron, whereas internal mass transfer and/or adsorption and surface reaction were important for high-purity iron.     

成都市典型有机溶剂使用行业VOCs组成成分谱及臭氧生成潜势研究

选取成都市5大典型有机溶剂使用行业——包装印刷业、人造板制造业、家具制造业、制鞋业和化学品制造业具有代表性的15家企业测定挥发性有机物(VOCs)排放组分,并对其不同组分的臭氧生成潜势(OFP)进行分析.研究结果表明:不同行业排放的VOCs之间存在较大差异,包装印刷业和人造板制造业主要排放含氧VOCs(OVOCs),家具制造业主要排放芳香烃和OVOCs,制鞋业和化学品制造业主要排放OVOCs、芳香烃和烷烃;芳香烃是化学反应活性最强的组分,对臭氧的生成贡献普遍较大,其中贡献最大的邻二甲苯及间二甲苯的OFP值分别为92.13 mg·m~(-3)和89.65 mg·m~(-3),二者占总OFP的40%;五大典型有机溶剂使用行业中,家具制造业对O_3生成的贡献最大,OFP贡献率为34.59%.     

Prevalence of malformed frogs in Kaoping and Tungkang river basins of southern Taiwan

In this study we found many amphibians with bizarre appearances, known as malformations in Pingtung County southern Taiwan. For this investigation we collected frogs inhabiting the Kaoping and Tungkang river watersheds between February 2006 and June 2007. Among the total number of 10,909 normal frogs (i.e., anurans) collected during the investigation period, the Indian rice frogs (Rana limnocharis) account for the greatest number next is the Chinese bullfrog (Rana rugulosa). Of all the 244 captured malformed frogs, the Indian rice frog account for the greatest proportion. These malformed frogs have their main distribution in upstream areas of these two rivers. Our result indicates that the appearance rate of malformed frogs is 1.8% in the upstream reaches of the Kaoping River and 2.6%, and 0.8%, respectively in the upstream and midstream reaches of the Tungkang river. The most-commonly-found malformation is the lack of palms, followed by the lack of appendages, exostosis, and a malformed appendicular. It is, therefore, reasonable to speculate that the causes for the malformation may be related to the increased organic pollutants and agricultural chemicals used in the upstream reaches of these two rivers.     

A pilot study of citizens' opinions on the Incident Command System in Taiwan

Local residents may have different views on disaster‐response modes depending on their cultural and socioeconomic background. The purpose of this study was to examine Taiwan residents' opinions on the Incident Command System (ICS). We performed a structured survey through face‐to‐face interviews in mudslide‐affected communities. Quantitative analysis showed that the residents exhibited a clear preference for the ICS core‐principle attributes of ‘integrated communications’, ‘transfer of command’ and ‘modular organisation’. By contrast, the residents tended towards a non‐ICS approach for ‘incident action plan’ and ‘manageable span of control’. Qualitative analysis revealed an uncertain attitude towards ‘transfer of command’ and ‘incident action plan’. Community acceptance is important in the promotion of the ICS. A better understanding of residents' preferences should be acquired through a broader community survey, allowing us to understand perspectives on the ICS among different societies and facilitate implementation of the ICS at the basic community level.     

Measuring seasonal variations of moisture in a landfill with the partitioning gas tracer test

Seven pilot-scale partitioning gas tracer tests (PGTTs) were conducted to assess the accuracy and reproducibility of this method for measuring water in municipal solid waste landfills. Tests were conducted in the same location over a 12-month period, and measured moisture conditions ranged from possible dry waste to refuse with a moisture content of 24.7%. The final moisture content of 24.7% was in reasonable agreement with gravimetric measurements of excavated refuse, where the moisture content was 26.5+/-6.0 CI%. Laboratory tests were used to assess the utility of the PGTT for measuring water in small pores, water sorbed to solid surfaces, and the influence of dry waste on PGTTs. These experiments indicated that when refuse surfaces are not completely solvated with water, PGTTs may produce misleading results (negative estimates) of water saturation and moisture content.     

铈(Ⅳ)-吐温40-邻苯二酚化学发光体系测定废水中的邻苯二酚

基于在吐温40存在下邻苯二酚与铈(Ⅳ)在酸性介质中发生化学发光反应,建立了测定邻苯二酚化学发光分析法。该法测定邻苯二酚的线性范围为3.0×10-7～5.0×10-5mol/L,检测限为1.0×10-7mol/L,相对标准偏差为3.0%(邻苯二酚浓度为5.0×10-6mol/L,平行测定11次)。用该法测定实验室废水中的邻苯二酚,结果令人满意。