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201.
Bioventing—the injection of air into the vadose zone to increase microbial activity—is a commonly used, proven technology for remediating volatile organic compounds present in the vadose zone. Passive systems driven by wind or solar power are both more cost‐effective and sustainable than conventional systems. Such a passive system is being applied successfully to remediate a site impacted with total petroleum hydrocarbons (TPH) and benzene, toluene, ethylbenzene, and xylenes (BTEX) in soil. Bioventing technology was approved by the regulatory agency as an interim remedial action to remove chemicals of concern (COCs) in the vadose zone. A bioventing pilot study was conducted to evaluate the effectiveness of COC removal and collect parameters for full‐scale design and implementation. To evaluate the potential to use wind‐driven bioventing technology, two mobile weather stations were installed at the site and monitored for one month for a wind speed study. Based on the pilot‐test data and wind speed research, 12‐inch diameter funnel/vane 360‐degree wind collectors were designed as passive wind‐driven air‐injection devices and connected to existing monitoring wells. The measured air velocity ranged from 20 to 110 feet per minute during the start‐up and the first three months of operation and maintenance. Monitoring indicated a 20 percent oxygen delivery and greater than 90 percent reduction in COC concentrations, demonstrating a successful sustainable remediation with no power requirement and minimal operation and maintenance. © 2012 Wiley Periodicals, Inc.  相似文献   
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Southern Alberta, which has a cold climate dominated by strong chinook winds, has the highest density of feedlot cattle in Canada. However, the quantity and quality of runoff from beef cattle (Bos taurus) feedlots in this unique region has not been investigated. Our objectives were to compare runoff quantity (1998-2002) with catch-basin design criteria; determine concentrations of selected inorganic chemical parameters (1998-2000) in runoff in relation to water quality guidelines and the potential implications of irrigating adjacent crop-land; and determine if total heterotrophs, total coliforms, and Escherichia coli (1998-2000) persisted in the catch-basin water and soil. Runoff (< 0.1 to 42.5 mm) for a 24-h duration that included maximum peak discharge was less than the recommended design criteria of 90 mm based on runoff from 24 h of rainfall with a 30-yr return period. We found that curve numbers between 52 and 96 (mode of 90) were required to match the USDA Natural Resources Conservation Service predicted runoff and actual runoff volumes. Total P posed the greatest threat to water quality guidelines, and K posed the greatest threat for exceeding crop fertilizer requirements if catch-basin effluent was used as irrigation water. Water in the catch basin had continually high populations of E. coli throughout the study, with values ranging between log10 2 and log10 8 100 mL(-1). In contrast, soil in the catch basin generally had low populations of E. coli that were < log10 2 g(-1) wet wt., but at times higher populations between log10 2 and log10 6 g(-1) wet wt. were also found.  相似文献   
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Occupational Health and Safety in Spain has improved considerably over the last decade, most likely due to a new concept where an overall concept of safety culture is defined. Important changes in industrial safety, hygiene, and psychosocial factors present an optimistic panorama for the future of Spain. Despite this general improvement, according to the European Convergence Program, Spanish statistics still offer far from good safety results. In fact, according to 1997 official statistics, Spain had the highest incidence rate for nonfatal occupational accidents of all European Union (EU) countries, and occupied third place for fatal accidents. This paper summarizes the organizational structure of the Spanish National System of Health & Safety at Work, its effective health and safety laws, and statistics on the Spanish work environment obtained from III Spanish National Survey on Work Conditions (1997). The researchers hope that the findings of this work will have an impact on Spanish industry that will subsequently bring about improvements in work conditions and develop assessment and intervention models in occupational health and safety, from a theoretical position integrating environmental, human, and organizational factors.  相似文献   
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In recent decades, protected-area management in many developing countries has been molded to win the support and participation of local people. Increasingly, research initiatives are undertaken to enhance understanding of the perceptions and attitudes of rural stakeholders. The effectiveness of the expanding protected-area system in China is critically constrained by similar considerations of community mentality. This paper provides an empirical assessment of local responses towards conservation efforts based on a case study of the recently established Shimentai Nature Reserve (SNR) situated in Yingde, Guangdong Province, China. Questionnaire surveys, face-to-face interviews, and group discussions were employed to gauge local residents' knowledge, perceptions, and expectations towards the SNR. The study covered seven villages situated in and around the reserve, grouped into far-zone (floodplain) and near-zone (upland) categories, accommodating Hakka (Han) and minority Yao peoples. Many respondents had inadequate knowledge, understanding, and perceptions of the reserve. Although most respondents welcomed the expected park-related dividends, the most affected near-zone villagers anticipated losses due to restriction on traditional resource-extraction activities in the forest. The local expectations were influenced by place of residence, emigration of rural young, and household affluence. The lack of local participation in management and inadequate dissemination of information posed obstacles to effective conservation. The high expectation of accruing benefits from development projects, including tourism, might be misplaced and might not be realized. The present honeymoon period of positive attitudes could end soon if the hopes remain unfulfilled for too long. The need to win sustained local support and provide alternative means of livelihood is emphasized.  相似文献   
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Nitrogen (N) loss during beef cattle (Bos taurus) feedlot manure composting may contribute to greenhouse gas emissions and increase ammonia (NH(3)) in the atmosphere while decreasing the fertilizer value of the final compost. Phosphogypsum (PG) is an acidic by-product of phosphorus (P) fertilizer manufacture and large stockpiles currently exist in Alberta. This experiment examined co-composting of PG (at rates of 0, 40, 70, and 140 kg PG Mg(-1) manure plus PG dry weight) with manure from feedlot pens bedded with straw or wood chips. During the 99-d composting period, PG addition reduced total nitrogen (TN) loss by 0.11% for each 1 kg Mg(-1) increment in PG rate. Available N at the end of composting was significantly higher for wood chip-bedded (2180 mg kg(-1)) than straw-bedded manure treatments (1820 mg kg(-1)). Total sulfur (TS) concentration in the final compost increased by 0.19 g kg(-1) for each 1 kg Mg(-1) increment in PG rate from 5.2 g TS kg(-1) without PG addition. Phosphogypsum (1.6 g kg(-1) P) addition had no significant effect on total phosphorus (TP) concentration of the final composts. Results from this study demonstrate the potential of PG addition to reduce overall N losses during composting. The accompanying increase in TS content has implications for use of the end-product on sulfur-deficient soils. Co-composting feedlot manure with PG may provide an inexpensive and technologically straightforward solution for managing and improving the nutrient composition of composted cattle manure.  相似文献   
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Bridges J 《Chemosphere》2003,52(9):1347-1351
Historically the procedures for human risk assessment and for risk assessment have developed separately with different terminologies and separate data bases. The identification that there are many common features and that sharing of certain types of data for risk assessment purposes would be beneficial is a driver towards a better integration of their procedures. Risk assessors are facing increasing challenges from governments, stimulated by public pressure for (i) human and environmental risk assessments of an ever growing number of products and processes, (ii) further restrictions of the use of animal tests and human studies on ethical grounds, (iii) the requirement to demonstrate that the assessments are independent, transparent and of high quality, (iv) reducing resources in particular a diminishing number of individuals with the scientific depth, breadth and independence act as risk assessors, (v) the need to incorporate new sciences continually and new discoveries into the risk assessment process. It is important for society that these challenges are met successfully. This requires changes in both risk assessment procedures and in the infrastructure needed to support them. Risk assessment is a science based process for establishing the likelihood of adverse effects to human health and to the environment from specific chemical, biological and physical agents. In the last few years there has been a renewed effort, by international bodies such as WHO, OECD and the EU, to achieve a more integrated and harmonised approach to risk assessment. Before examining the potential for a more integrated approach to risk assessment it is timely to consider the key factors which have led to the current position.  相似文献   
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ABSTRACT: In 1996, the Big Thompson Watershed Forum (BTWF) was formed “to assess and protect the quality of water” in the Big Thompson Watershed in northern Colorado. However, until 1999, water quality monitoring in the watershed was performed by many state, local, and federal agencies with no coordination among programs and with few efforts toward efficiency, data comparability, or information exchange. To better meet the needs of its stakeholders, the BTWF since 1999 has been actively pursuing the design and implementation of a cooperative water quality monitoring program. The program design involved consensus building among the funding participants, primarily drinking water providers. The final design included 38 parameters to be sampled 15 times per year at 24 stream and canal locations plus two reservoirs. Although the collaborative consensus based approach has been successful for the BTWF, this approach has its drawbacks; most notable among these are the time and labor this approach requires. Also, the BTWF struggled with achieving equal representation of all interests, since those agencies that provided funding had the greatest voice in the final product. While a collaborative approach may not always be best for monitoring program design, it should be appropriate for many watershed organizations that face the common problem of severe financial constraints.  相似文献   
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