Molecular composition of recycled organic wastes,as determined by solid-state 13C NMR and elemental analyses

Using solid state ¹³C NMR data and elemental composition in a molecular mixing model, we estimated the molecular components of the organic matter in 16 recycled organic (RO) wastes representative of the major materials generated in the Sydney basin area. Close correspondence was found between the measured NMR signal intensities and those predicted by the model for all RO wastes except for poultry manure char. Molecular nature of the organic matter differed widely between the RO wastes. As a proportion of organic C, carbohydrate C ranged from 0.07 to 0.63, protein C from <0.01 to 0.66, lignin C from <0.01 to 0.31, aliphatic C from 0.09 to 0.73, carbonyl C from 0.02 to 0.23, and char C from 0 to 0.45. This method is considered preferable to techniques involving imprecise extraction methods for RO wastes. Molecular composition data has great potential as a predictor of RO waste soil carbon and nutrient outcomes.     

Environmental impact and human exposure to PCBs in Guiyu, an electronic waste recycling site in China

PCB levels in fish (collected from local rivers), atmosphere and human milk samples have been studied to determine the exposure levels of PCBs for local residents and e-waste workers in Guiyu, a major electronic waste scrapping center in China. The source appointment and correlation analyses showed that homologue composition of PCBs in 7 species of fish were consistent and similar to commercial PCBs Aroclor 1248. PCB levels in air surrounding the open burning site were significantly higher than those in residential area. Inhalation exposure contributed 27% and 93% to the total body loadings (the sum of dietary and inhalation exposure) of the local residents, and e-waste workers engaged in open burning respectively. Total PCB concentrations in human milk ranged from N.D. to 57.6 ng/g lipid, with an average of 9.50 ng/g lipid. The present results indicated that commercial PCBs derived from e-waste recycling are major sources of PCBs accumulating in different environmental media, leading to the accumulation of high chlorinated biphenyls in human beings.     

A study of ground-level ozone pollution, ozone precursors and subtropical meteorological conditions in central Taiwan

Hourly concentrations of ozone (O(3)), 55 volatile organic compounds (VOCs, ozone precursors) and nitrogen oxides (NOx) were measured at an upwind urban site, a downwind suburban site, and a rural site in central Taiwan, from January 2003 to December 2006. VOC and NOx mean concentrations showed a gradient from high to low across the urban (56 ppb and 34 ppb), suburban (38 ppb and 27 ppb) and rural sites (25 ppb and 21 ppb) but a reverse gradient in ozone across these sites (24, 27, and 29 ppb, respectively). Although there was about twice the difference in VOC concentrations between the urban and rural sites, nearly 65% ozone formation potential was contributed to by the same 9 VOCs. Seasonal patterns showed peak ozone levels in autumn and minima in summer at the urban site, but minima in winter at the downwind suburban and rural sites. Ozone precursor levels, on the other hand, were lowest in summer and highest in winter. The diurnal pattern showed that ozone levels peaked one hour later at the rural site than at the urban site. The ethylbenzene to m,p-xylene ratio, an indicator of the age of the air mass, increased from 0.4 at the urban site to 0.6 at the suburban site and 0.8 at the rural site during daily peak ozone times. This finding suggests the transport of ozone and precursors from upwind to downwind producing elevated ozone levels in the suburban and rural areas. Ozone episodes occurred mostly in days with a mean midday UV index of 6.5 (1 UV index=100 J m(-2)) and wind speed at 1.3 m s(-1) at all three sites.     

Effects of fly ash addition on physical properties of porous clay-fly ash composites via polymeric replica technique

The porous composites of clay and fly ash have the potential to be used in many fields, such as catalyst support and gas adsorbents. In this study, various ratios of fly ash (1–2) with different percentage of suspension (50–70 wt%) were applied to produce porous clay-fly ash composites via polymeric replica technique. Fabrication process starts by mixing clay and fly ash in distilled water to form slurry. The process is followed by fully immersing polymer sponge in slurry. The excess slurry is then removed through squeezing. Finally, the sponge coated with slurry is sintered at 500 and 1250 °C for 1 h. It is found that the compressive strength of porous composites improves significantly (0.178–1.28 MPa) when the amount of clay-fly ash suspension mixture (50–70 wt%) increases. The compressive strength of porous composites is mainly attributed to the mullite, quartz and amorphous phase formations. These results are supported by X-ray diffraction analysis. On the other hand, increase in the amount of suspension reduces the apparent density (from 2.44 to 2.32 g/cm³) and porosity (from 97 to 85 %). The reduction in apparent density is believed to be caused by the presence of high fly ash content in porous composites. The melted fly ash cenospheres have closed the internal pores and increased density of samples. Higher suspension level not only reduces porosity, but also increases close pores of the porous composites. The results are justified through the observation from the structures of porous clay-fly ash composites.     

湛江特呈岛红树林植物群落的结构和动态特征

对特呈岛红树林植被进行多次和全面的调查,通过采用格子样的方法,选取面积为100～800 m^2的样地,每片样地再分成若干10 m×10 m的样方,对红树林样地内的植物进行每木测量,记录各植物的种名、胸径、高度、冠幅等,并进行重要性以及多样性等常规的群落分析,判定该地区植被的生长特征以及研究其演替动态变化。结果表明：①面积较大的群落主要有3个类型,即白骨壤群落（Avicennia marina）、白骨壤＋红海榄群落（Avicennia marina＋Rhizophora stylosa）、白骨壤-桐花树群落（Avicennia marina-Aegiceras corniculatum）;其它面积较小的群落有：白骨壤＋红海榄-木榄＋桐花树群落（vicennia marina＋Rhizophora stylosa-Bruguiera gymnorrhiza＋Aegiceras corniculatum）、红海榄＋木榄群落（Rhizophora stylosa＋Bru-guiera gymnorrhiza）;②在3个主要群落中,优势种的苗木和小树相对较少,优势种群的年龄结构均为衰退型;③各群落的Simpson指数关系为：白骨壤＋红海榄群落﹥红海榄＋木榄群落﹥白骨壤＋红海榄—木榄＋桐花树群落﹥白骨壤—桐花树群落﹥白骨壤群落;白骨壤群落的重要值为300,为典型的单优群落;④特呈岛的白骨壤群落是中国该类群落中面积最大的,目前长势良好,无病虫害,并且红树林外缘的白骨壤枝干在波浪冲刷或人为原因下,受到较严重的侵蚀,其幼树在林外缘基本无法存活,需要加强保护,对其生理生态学特征也值得进一步深入研究。     

The fate of recombinant plasmids during composting of organic wastes

Composting was investigated as a means for safe disposal of organic waste containing bacteria that carry transgenes in recombinant plasmids. To generate model recombinant plasmids, a mobile IncQ plasmid, RSF1010, and a non-mobile plasmid, pGFP, were genetically modified to carry a DNA segment encoding both green fluorescent protein and kanamycin resistance and were designated as RSF1010-GFPK and pGFPK. Escherichia coli (E. coli) C600 harboring these plasmids were inoculated into chicken manure specimens that were placed in compost at 20 and 60 cm from the bottom of a 1.0-m high compost bin. Control specimens were held at ambient temperature. By day 10, compost temperatures at the lower and upper levels of the bin had reached 45.3 and 61.5°C, respectively, and at both levels the target E. coli had been inactivated and the plasmids had lost their capacity to be transformed or mobilized. Furthermore, based on real time Polymerase chain reaction (PCR), the transgene fragments along with the host chromosomal DNA fragment from specimens at the upper level had been degraded beyond the detection limit. However, at the lower level where temperatures remained below 48°C these fragment persisted to day 21. At ambient temperatures (0–8°C), the E. coli, plasmids and the transgene fragments persisted in manure specimens throughout the 21 day test period. The study showed the potential for composting as a safe procedure for disposal of bacteria carrying transgenes in recombinant plasmids.     

新疆CDM项目的开发状况与前景分析

随着世界经济的进一步发展,能源的需求量持续增加,CO2的排放量还将持续增长.温室气体排放带来的气候变暖问题会进一步加剧。清洁发展机制(CDM)是在《京都议定书》框架下,发达国家与发展中国家就碳减排进行合作的重要机制.发展中国家通过CDM可以获得实现节能减排的资金援助和先进技术,促进国家的经济发展和环境的可持续发展。就新疆CDM项目的发展状况、国际碳市场的前景,以及新疆CDM项目开发存在的问题和解决方法方面进行了探讨。     

Detection and Molecular Characterization of Human Noroviruses in Korean Groundwater Between 2008 and 2010

RT-PCR, nucleotide sequencing, and phylogenetic analysis were performed for genotyping and molecular characterization of noroviruses isolated from Korean groundwater. Among 160 samples collected from 80 sites between 2008 and 2010, 14 samples (8.7?%) from 12 sites were positive for noroviruses (NoVs). The percentages of NoV-positive samples in 2008, 2009, and 2010 were 22.2, 3.2, and 0?%, respectively, representing a yearly decrease. GII-positive samples (n?=?9, 5.6?%) outnumbered GI-positive samples (n?=?5, 3.1?%). The genotypes of the GI NoVs were GI.2, GI.5, and GI.6, and the genotypes of the GII NoVs were all GII.4. One sample, HM623465, was very similar to CUK-3 and CBNU2 and two GII.4 sequences isolated from the stool of Korean gastroenteritis patients. A BLASTN search revealed several nucleotide sequences highly similar to those of NoVs isolated in this study. The original isolation sources for these similar NoVs were mostly stool (n?=?731, 80.0?%) and groundwater (n?=?135, 14.8?%), and all the countries from which they were isolated were almost in Asia (96.0?%); specifically, China (n?=?192, 21.0?%), Japan (n?=?383, 41.9?%), Korea (n?=?296, 32.4?%), and other Asian countries (n?=?6, 0.7?%). These results suggest that Korean groundwater might be contaminated with NoVs from the stool of infected patients and that these NoVs in turn cause new cases of gastroenteritis through a typical fecal-oral route with region-specific circulation. Therefore, it is important to properly treat sewage, which may include waterborne viruses and manage point sources in groundwater for national health and sanitation. In addition, continuous molecular surveillance remains important for understanding circulating NoVs.