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1.
Woody biomass waste is generated throughout California from forest management, hazardous fuel reduction, and agricultural operations. Open pile burning in the vicinity of generation is frequently the only economic disposal option. A framework is developed to quantify air emissions reductions for projects that alternatively utilize biomass waste as fuel for energy production. A demonstration project was conducted involving the grinding and 97-km one-way transport of 6096 bone-dry metric tons (BDT) of mixed conifer forest slash in the Sierra Nevada foothills for use as fuel in a biomass power cogeneration facility. Compared with the traditional open pile burning method of disposal for the forest harvest slash, utilization of the slash for fuel reduced particulate matter (PM) emissions by 98% (6 kg PM/BDT biomass), nitrogen oxides (NOx) by 54% (1.6 kg NOx/BDT), nonmethane volatile organics (NMOCs) by 99% (4.7 kg NMOCs/BDT), carbon monoxide (CO) by 97% (58 kg CO/BDT), and carbon dioxide equivalents (CO2e) by 17% (0.38 t CO2e/BDT). Emission contributions from biomass processing and transport operations are negligible. CO2e benefits are dependent on the emission characteristics of the displaced marginal electricity supply. Monetization of emissions reductions will assist with fuel sourcing activities and the conduct of biomass energy projects.  相似文献   

2.
Synthetic fibers as an indicator of land application of sludge   总被引:6,自引:0,他引:6  
Synthetic fabric fibers have been proposed as indicators of past spreading of wastewater sludge. Synthetic fiber detectability was examined in sludges (dewatered, pelletized, composted, alkaline-stabilized) and in soils from experimental columns and field sites applied with those sludge products. Fibers (isolated by water extraction and examined using polarized light microscopy) were detectable in sludge products and in soil columns over 5 years after application, retaining characteristics observed in the applied sludge. Concentrations mirrored (within a factor of 2) predictions based on soil dilution. Fibers were detectable in field site soils up to 15 years after application, again retaining the characteristics seen in sludge products. Concentrations correlated with residual sludge metal concentration gradients in a well-characterized field site. Fibers found along preferential flow paths and/or in horizons largely below the mixed layer suggest some potential for translocation. Synthetic fibers were shown to be rapid and semi-quantitative indicators of past sludge application.  相似文献   

3.
Environmental Science and Pollution Research - Slowing and reversing climate change and keeping energy prices at affordable levels are the main important achievements of the use of renewable...  相似文献   

4.
Phytotoxicity of dredged sediment from Hangzhou section of the Grand Canal as land application was evaluated by pakchoi (Brassica chinensis L.) germination tests and pot experiments. Germination rates of pakchoi in the dredged sediment and in sediment-applied soils were both significantly higher than that in the soil controls, while the germination rate between the sediment-applied soils was no significant difference. In pot experiments, plant height and biomass were increased by the dredged sediment application rate in the rate of lower than 540 t ha(-1), but decreased when the application rate was over this rate. Concentrations of Zn and Cu in pakchoi were linearly increased with the increasing of the application rate of the dredged sediment. Both plant height and biomass of pakchoi in sediment-treated red soil were higher than that in sediment-treated paddy soil, regardless the application rate. The results suggest that plant biomass of pakchoi may be used as an indicator of the phytotoxicity of the dredged sediment. It also showed that red soil is more suitable to accept the dredged sediment than paddy soil, and 270 t ha(-1) is a safe application rate both in red soil and paddy soil.  相似文献   

5.
Population models can be used to place observed toxic effects into an assessment of the impacts on population-level endpoints, which are generally considered to provide greater ecological insight and relevance. We used an individual-based model of mink to evaluate the population-level effects of exposure to polychlorinated biphenyls (PCBs) and the impact that different remediation strategies had on mink population endpoints (population size and extinction risk). Our simulations indicated that the initial population size had a strong impact on mink population dynamics. In addition, mink populations were extremely responsive to clean-up scenarios that were initiated soon after the contamination event. In fact, the rate of PCB clean-up did not have as strong a positive effect on mink as did the initiation of clean-up (start time). We show that population-level approaches can be used to understand adverse effects of contamination and to also explore the potential benefits of various remediation strategies.  相似文献   

6.
The importance of the use of potassium in agriculture is increasing in South Asia for making most productive use of the nutrient in terms of economic returns. Nutrient supply traditionally by cattle manure is constrained by its insufficient availability. Municipal waste compost may be an alternative source of nutrient supplements. Field experiments were conducted at the Experimental Farm of Calcutta University, West Bengal, India during the wet seasons of 1997, 1998 and 1999 on flooded lowland rice. Potassium fractions in municipal waste compost and cattle manure were determined by sequential extraction and also the potassium uptake by rice to compare the effectiveness of municipal waste compost with traditional manure. Potassium was significantly bound to the organic matter in municipal waste compost. Potassium uptake by rice grain and straw increased significantly with the combined application of organics and fertilizers and it was higher in grain than in straw. Water-soluble and non-exchangeable potassium contents of municipal waste compost and cattle manure were highly correlated with the uptake of potassium by straw and grain. Exchangeable and residual potassium were also significantly correlated with the uptake of potassium by straw and grain of rice. Much higher uptake of K in rice straw and rain resulted from applying the manures in conjunction with fertilizers than when applied singly.  相似文献   

7.
The objective of this study was to determine whether ultraviolet-light-emitting diodes (UV-LEDs) could serve as an efficient photon source for heterogeneous photocatalytic oxidation (PCO). An LED module consisting of 12 high-power UV-A (lambda max = 365 nm) LEDs was designed to be interchangeable with a UV-A fluorescent black light blue (BLB) lamp for a bench scale annular reactor packed with silica-titania composite (STC) pellets. Lighting and thermal properties of the module were characterized to assess its uniformity and total irradiance. A forward current (I(F)) of 100 mA delivered an average irradiance of 4.0 mW cm(-2) at a distance of 8 mm, which is equivalent to the maximum output of the BLB, but the irradiance of the LED module was less uniform than that of the BLB. The LED and BLB reactors were tested for the oxidization of ethanol (50 ppm(v)) in a continuous-flow-through mode with 0.94 sec residence time. At the same average irradiance, the UV-A LED reactor resulted in a lower CO2 production rate (19.8 vs. 28.6 nmol L(-1) s(-1)), lower ethanol removal (80% vs. 91%), and lower mineralization efficiency (28% vs. 44%) than the UV-A BLB reactor. Ethanol mineralization was enhanced with the increase of the irradiance at the catalyst surface. This result suggests that reduced ethanol mineralization in the LED reactor relative to the BLB reactor at the same average irradiance could be attributed to the nonuniform irradiance over the photocatalyst, that is, a portion of the catalyst was exposed to less than the average irradiance. The potential of UV-A LEDs may be fully realized by optimizing the light distribution over the catalyst and utilizing their instantaneous "on" and "off" feature for periodic irradiation. Nevertheless, our results also showed that the current UV-A LED module had the same wall plug efficiency (WPE) of 13% as that of the UV-A BLB, demonstrating that UV-A LEDs are a viable photon source both in terms of WPE and PCO efficiency.  相似文献   

8.
Prior to the application of biochar as an agricultural improver, attention should be paid to the potential introduction of toxicants and resulting unintended impacts on the environment. In the present study, the concentrations of polycyclic aromatic hydrocarbons (PAHs), heavy metals, and mineral elements were determined in maize and sludge biochars produced at 100 °C increments between 200 and 700 °C. The concentration ranges of total PAHs were 358–5,136 μg kg?1 in maize biochars and 179–70,385 μg kg?1 in sludge biochars. The total heavy metals were detected at the following concentrations (mg kg?1): Cu, 20.4–56.7; Zn, 59.7–133; Pb, 1.44–3.50; Cd, <0.014; Cr, 8.08–21.4; Ni, 4.38–9.82 in maize biochars and Cu, 149–202; Zn, 735–986; Pb, 54.7–74.2; Cd, 1.06–1.38; Cr, 180–247; Ni, 41.1–56.1 in sludge biochars. The total concentrations of PAHs and heavy metals in all maize biochars and most sludge biochars were below the control standards of sludge for agricultural use in China, the USA, and Europe. The leachable Mn concentrations in sludge biochars produced at below 500 °C exceeded the groundwater or drinking water standards of these countries. Overall, all the maize biochars were acceptable for land application, but sludge biochars generated at temperatures between 200 and 500 °C were unsuitable for application as soil amendments due to their potential adverse effects on soil and groundwater quality.  相似文献   

9.
Brownfield redevelopment involves numerous uncertain financial risks associated with market demand and land value. To reduce the uncertainty of the specific impact of land value and social costs, this study develops small-scale risk maps to determine the relationship between population risk (PR) and damaged land value (DLV) to facilitate flexible land reutilisation plans. This study used the spatial variability of exposure parameters in each village to develop the contaminated site-specific risk maps. In view of the combination of risk and cost, risk level that most affected land use was mainly 1.00 × 10?6 to 1.00 × 10?5 in this study area. Village 2 showed the potential for cost-effective conversion with contaminated land development. If the risk of remediation target was set at 5.00 × 10?6, the DLV could be reduced by NT$15,005 million for the land developer. The land developer will consider the net benefit by quantifying the trade-off between the changes of land value and the cost of human health. In this study, small-scale risk maps can illuminate the economic incentive potential for contaminated site redevelopment through the adjustment of land value damage and human health risk.  相似文献   

10.
由于航空工业的特殊性,航空企业节能减排相对滞后,节能减排工作迫在眉睫.为使航空工业节能减排的方案全面、科学、客观,基于现代风险评价方法,根据中国航空企业系统的客观实际,采用模糊综合评价法建立了航空企业节能减排的评价指标体系和评价方法,并确定了该评价指标体系中各指标的权重,进而得到各指标隶属度、模糊矩阵.同时,进行了实例...  相似文献   

11.
Heterogeneous water phase catalysis as an environmental application: a review   总被引:15,自引:0,他引:15  
Catalytic water phase processes as an environmental application is a relatively novel subject with tremendous potential in the near future. This review of 120 references presents the wide scale of heterogeneous water phase applications studied mainly within past five years. Both oxidation and hydrogenation processes are included as well as TiO2 assisted photocatalysis. According to the references, heterogeneous catalysis is developing rapidly. New bimetallic catalysts and supports with higher surface area have improved catalytic efficiency in both oxidation and hydrogenation processes. It also seems that study on use of some waste materials such as red mud as catalyst is a very progressive field. On the whole, the chemical aspects are pretty well known, but the catalyst durability, and in many cases activity as well, has to be improved.  相似文献   

12.
This paper describes the statistical methodology applied to evaluate the performance of the long-range dispersion models that were used in the modelling activities of ETEX (European Tracer EXperiment). The availability of a large number of models makes this exercise rather unique. These models are used for the practical purpose to quantify the contamination effects over a vast area, following a hypothetical accidental release of harmful material. This makes the quality judgement that could be attributed to the results of each model particularly important.The statistical indicators considered to be the most effective for the evaluation of long-range dispersion models are introduced and commented, with specific examples in the frame of ETEX simulations. The importance of using several indices and critically interpreting the results is discussed.  相似文献   

13.
Thymol is a natural substance increasingly used as an alternative to pesticides in the fight against the Varroa destructor mite. Despite the effectiveness of this phenolic monoterpene against Varroa, few articles have covered the negative or side effects of thymol on bees. In a previous study, we have found an impairment of phototaxis in honeybees following application of sublethal doses of thymol—lower or equal to 100 ng/bee—under laboratory conditions. The present work shows the same behavioral effects on bees from hives treated with Apilife Var®, a veterinary drug containing 74 % thymol, with a decrease in phototactic behavior observed 1 day after treatment. Thus, thymol causes disruption of bee phototactic behavior both under laboratory conditions as well as in beehives. The bee exposure dose in treated hives was quantified using gas chromatography coupled to mass spectrometry (GC–MS), giving a median value of 4.3 μg per body 24 h after treatment, with 11 ng in the brain. The thymol level in 20 organic waxes from hives treated with Apilife Var® was also measured and showed that it persists in waxes (around 10 mg/kg) 1 year after treatment. Thus, in the light of (1) behavioral data obtained under laboratory conditions and in beehives, (2) the persistence of thymol in waxes, and (3) the high load on bees, it would appear important to study the long-term effects of thymol in beehives.  相似文献   

14.
T Öberg  JGT Bergström 《Chemosphere》1985,14(8):1081-1086
The production of polychlorinated dioxins and dibenzofurans shows a strong correlation with the production of hexachlorobenzene. Hexachlorobenzene can be used as an indicator for the production of chlorinated aromatics.  相似文献   

15.
发达国家污染土地置换开发管理实践及其对我国的启示   总被引:14,自引:0,他引:14  
污染土地置换开发是一个复杂的过程,涉及技术、法律、经济和社会等诸多问题.选择管理技术相对比较成熟和先进的美国、欧盟国家、加拿大以及日本作为案例,深刻剖析国际上污染土地置换开发管理的经验与教训,提出有效的城市土地利用规划、公平合理的经济责任界定、合适的资金筹措机制、灵活选择土壤污染修复目标、污染土地风险评估等级划分、多利益方的共同参与等6点启示,以期对我国日益受到重视的污染土地置换开发管理工作提供借鉴.  相似文献   

16.

An increasing number and amount of pharmaceuticals for human and veterinary use currently reach the aquatic environment, and the determination of their effects on aquatic organisms becomes of major importance. The 96-h fish lethal test is one of the conventional assays required for environmental hazardous assessment, but it is extremely time-consuming and costly, and it raises ethical concerns. In a broad study, we compared the ability of cell-based assays to detect, in absolute terms, lethal toxicity in fish due to pharmaceuticals in order to select sensitive cell lines to be posteriorly used as an alternative to fish testing. This study also explored the sensitivity of the rat cardiomyoblast H9c2(2-1) cell line and the suitability of the sulforhodamine B colorimetric assay regarding 15 pharmaceuticals belonging to 9 different therapeutic classes. The relation between in vivo and in vitro data was expressed as LC50,96h/EC50 ratios, and 66% of concordant data were attained. Accordingly, it was possible to conclude that cell-based assays could be considered a suitable alternative to fish lethal testing for pharmaceuticals, which, after validation, may dramatically reduce the number of fish required for environmental hazardous assessment. Several cell lines were selected as promising alternatives, but H9c2(2-1), HepG2, PLHC-1, and RTG-2 could be considered suitable starting cell types for further studies, as relevant results were obtained with low exposure times.

  相似文献   

17.
Deterioration of overlying water quality during toxicity tests with benthic invertebrates is a serious problem with some sediments. One solution is periodic renewal of overlying water. However, this is either labour intensive or requires construction and maintenance of special equipment. Furthermore, water renewal has the potential for flushing toxic chemicals out of the test chamber and establishes nonequilibrium conditions between the water and sediment. An alternative is testing under static conditions using atypical test vessels (e.g. Imhoff settling cones) with a large water volume (1 l) overlaying a much smaller sediment volume (e.g. 15 ml). This results in dramatic improvement of overlying water quality compared to standard static toxicity tests. Compared to water renewal, the test method is much simpler, all toxic substances leached from the sediment are retained in the test vessel, and contaminant concentrations in water and sediment have more time to equilibrate. Chronic sediment toxicity tests (10-28 days) have been conducted successfully under these conditions with Chironomus riparius, Hexagenia sp., Hyalella azteca and Tubifex tubifex.  相似文献   

18.
Environmental Science and Pollution Research - There has been growing interest in studying the relationship between energy strategies (energy efficiency and energy diversity) and economic growth to...  相似文献   

19.
Environmental Science and Pollution Research - Activated carbon prepared from grape branches was used as a remarkable adsorbent to uptake naproxen and treat a synthetic mixture from aqueous...  相似文献   

20.
A new and innovative process for the biotechnological production of L-lysine is presented, exemplified here by the fermentative production of the feed additive Biolys60. The novel feature of this product is that the entire manufacturing concept, i.e. the production strain, the raw materials, all process stages and the product specifications have been systematically tailored for optimal environmental compatibility and for minimum resource depletion and waste. The process completely dispenses with the need to discharge residual and waste material and reduces the handling of hazardous materials to a minimum. Since only a few process stages are involved, the method is economical to use and investment outlay is reduced. The process, which also leads to a higher grade product, is thus highly attractive in both ecological and economical terms. By boosting the nutrient value of the plant-based feedstuffs, the product itself makes an cost-effective contribution towards a more sustainable form of animal feeding and by reducing nitrogen emission levels promotes a more environmentally compatible form of animal husbandry.  相似文献   

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