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951.
About 3600 tonnes food waste are discarded in the landfills in Hong Kong daily. It is expected that the three strategic landfills in Hong Kong will be exhausted by 2020. In consideration of the food waste management environment and community needs in Hong Kong, as well as with reference to the food waste management systems in cities such as Linköping in Sweden and Oslo in Norway, a framework of food waste separation, collection, and recycling for food waste valorization is proposed in this paper. Food waste can be packed in an optic bag (i.e., a bag in green color), while the residual municipal solid waste (MSW) can be packed in a common plastic bag. All the wastes are then sent to the refuse transfer stations, in which food waste is separated from the residual MSW using an optic sensor. On the one hand, the sorted food waste can be converted into valuable materials (e.g., compost, swine feed, fish feed). On the other hand, the sorted food waste can be sent to the proposed Organic Waste Treatment Facilities and sewage treatment works for producing biogas. The biogas can be recovered to produce electricity and city gas (i.e., heating fuel for cooking purpose). Due to the challenges faced by the value-added products in Hong Kong, the biogas is recommended to be upgraded as a biogas fuel for vehicle use. Hopefully, the proposed framework will provide a simple and effective approach to food waste separation at source and promote sustainable use of waste to resource in Hong Kong.  相似文献   
952.
953.
Fischer G  Müller T  Ostrowski R  Dott W 《Chemosphere》1999,38(8):1745-1755
Exposure to secondary metabolites of airborne fungi in waste handling facilities is discussed in regard to potential toxic impacts on human health. The relevance of mycotoxins has been intensely studied in connection with contamination of food and feed. Toxic secondary metabolites are expected to be present in airborne spores, but exposure to mycotoxins in bioaerosols has not been studied sufficiently. Aspergillus fumigatus is one of the most frequent species in the air of compost plants. A wide range of secondary metabolites was found in pure cultures of freshly isolated strains of A. fumigatus. Tryptoquivaline, a compound with tremorgenic properties, and trypacidin, for which no toxic properties are described, were found in native bioaerosols in a compost facility. The highly toxic metabolites gliotoxin and verruculogen were not found in the bioaerosols.  相似文献   
954.
Environmental Chemistry Letters - Climate change and the unsustainability of fossil fuels are calling for cleaner energies such as methanol as a fuel. Methanol is one of the simplest molecules for...  相似文献   
955.
本世纪期间,技术进展已经使农作物生产率发生了革命,但农作物产率的提高已经开始放慢,而世界人口却继续增长.土地退化和水资源的压力是对非常需要的土地生产率提高的严重障碍.满足21世纪全球食品需要将要求一致的人口控制政策,推进可持续消费,和大大提高我们对土地、水及其它自然资源的使用效率.本文提供了对这些问题的前瞻性分析和解决这些问题的建议.  相似文献   
956.
Over a period of two years (2000-2001), sediment samples were extracted from 40 silt traps (STs) spread through the combined sewer system of Paris. All sediment samples were analysed for physico-chemical parameters (pH, organic matter content, grain size distribution), with total hydrocarbons (THs) and 16 polycyclic aromatic hydrocarbons (PAHs) selected from the priority list of the US-EPA. The two main objectives of the study were (1) to determine the hydrocarbon contamination levels in the sediments of the Paris combined sewer system and (2) to investigate the PAH fingerprints in order to assess their spatial variability and to elucidate the PAH origins. The results show that there is some important inter-site and intra-site variations in hydrocarbon contents. Despite this variability, TH and PAH contamination levels (50th percentile) in the Parisian sewer sediment are estimated at 530 and 18 microg g(-1), respectively. The investigation of the aromatic compound distributions in all of the 40 STs has underlined that there is, at the Paris sewer system scale, a homogeneous PAH background pollution. Moreover, the study of the PAH fingerprints, using specific ratios, suggests the predominance of a pyrolytic origin for those PAHs fixed to the sewer sediment.  相似文献   
957.
Biodegradation of phthalate esters by two bacteria strains   总被引:22,自引:0,他引:22  
Chang BV  Yang CM  Cheng CH  Yuan SY 《Chemosphere》2004,55(4):533-538
In this study two aerobic phthalic acid ester (PAE) degrading bacteria strains, DK4 and O18, were isolated from river sediment and petrochemical sludge, respectively. The two strains were found to rapidly degrade PAE with shorter alkyl-chains such diethyl phthalate (DEP), dipropyl phthalate (DPrP), di-n-butyl phthalate (DBP), benzylbutyl phthalate (BBP) and diphenyl phthalate (DPP) are very easily biodegraded, while PAE with longer alkyl-chains such as dicyclohexyl phthalate (DCP) and dihexyl phthalate (DHP) and di-(2-ethylhexyl) phthalate (DEHP) are poorly degraded. The degradation rates of the eight PAEs were higher for strain DK4 than for strain O18. In the simultaneous presence of strains DK4 and O18, the degradation rates of the eight PAEs examined were enhanced. When the eight PAEs were present simultaneously, degradation rates were also enhanced. We also found that PAE degradation was delayed by the addition of nonylphenol or selected polycyclic aromatic hydrocarbons (PAHs) at a concentration of 1 microg/g in the sediment. The bacteria strains isolated, DK4 and O18, were identified as Sphigomonas sp. and Corynebacterium sp., respectively.  相似文献   
958.
Soil samples from the vicinity of a non-ferrous metal smelter near Plovdiv, Bulgaria contained very high concentrations of cadmium, lead and zinc (up to 140, 4900 and 5900 mg kg(-1), respectively). A roadside soil in a relatively uncontaminated area also contained high concentrations of the same metals (24, 1550 and 1870 mg kg(-1), respectively) indicating that the transport of ores could be a source of contamination. Even though the lead isotope ratios in all the samples fell within a very narrow range (for example, 1.186-1.195 for (206)Pb/(207)Pb), the samples could be differentiated into three distinct groups: ores ((206)Pb/(207)Pb and (208)Pb/(207)Pb ratios of 1.1874-1.1884 and 2.4755-2.4807, respectively), current deposition (1.1864 and 2.4704-2.4711, respectively) and local background (1.1927-1.1951 and 2.4772-2.4809, respectively). Although most of the current deposition has its origin in the ores used at the smelter, up to 12% could be from other sources such as petrol lead.  相似文献   
959.
Photocatalytic oxidation of triclosan   总被引:1,自引:0,他引:1  
Yu JC  Kwong TY  Luo Q  Cai Z 《Chemosphere》2006,65(3):390-399
In the spring of 2003, there was an outbreak of the severe respiratory syndrome (SARS) in Hong Kong. Health concerns have thus triggered an increased and predominant use of various types of household cleansing agents such as triclosan (5-chloro-2-(2,4-dichlorophenoxy)phenol). However, it has been reported recently that triclosan could be photochemically converted to toxic 2,8-dichlorodibenzo-p-dioxin (2,8-Cl(2)DD) in the environment. It is therefore necessary to develop environmentally friendly methods for the treatment of triclosan. To this end, photocatalytic degradation of triclosan in aqueous solution was conducted using TiO(2) (Degussa P25) under irradiation of UV light (lambda < 365 nm). It was found that triclosan could be degraded by this approach. Hydrogen peroxide was added to enhance the degradation process, and the optimal initial hydrogen peroxide concentration for triclosan degradation was 0.005% (w/v). Product identification indicated that triclosan oxidation occurred at its phenol moiety and yielded quinone and hydroquinone intermediates. The formation of a dichlorophenol intermediate in triclosan degradation suggested bond-breaking of the ether linkage occurred during the process. Moreover, no chlorinated dibenzo-p-dioxin congener was detected. These findings confirm that the photocatalytic degradation of triclosan is an environmentally friendly process.  相似文献   
960.
The toxicity of leachate water from acid-sulphate soil to the early life stages of Australian bass, Macquaria novemaculeata, incubated in seawater was evaluated. Acid-sulphate soil leachate water (pH> or =6.8) delayed the hatching of fertilised eggs, but after 48 h the per cent hatching was normal. In comparison, acidic saline water (25 per thousand salinity) at pH 4.0 or less prevented embryos from hatching. The survival of yolk-sac larvae exposed to acid-sulphate soil leachate water at a concentration of 32% in seawater and an initial pH of 7.2, was significantly different to controls after 96 hours. In corresponding tests with only acidified saline water (20 per thousand salinity), pH levels equal to or below 5.0 killed yolk-sac larvae after 96 h exposure. Aluminum showed a pH dependent toxicity to yolk-sac larvae, with added aluminium as low as 200 microg litre(-1) having a significant effect on larval survival at pH 5.5, and concentrations of 600-800 microg litre(-1) having a significant effect on larval survival at an initial pH range of 6.0 < pH < 6.8. It was concluded that significant mortality of the early life stages of Australian bass would occur if they are exposed to acid-sulphate soil leachate that results in a pH in the receiving estuarine water below 5.5, or when the pH is below 6.8 and aluminium is present at a total concentration of 800 microg litre(-1) or greater.  相似文献   
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