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991.
The increased use of grain-based feed for livestock during the last two decades has contributed, along with other factors, to a rise in grain prices that has reduced human food security. This circumstance argues for feeding more forages to livestock, particularly in the tropics where many livestock are reared on small farms. Efforts to accomplish this end, referred to as the ‘LivestockPlus’ approach, intensify in sustainable ways the management of grasses, shrubs, trees, and animals. By decoupling the human food and livestock feed systems, these efforts would increase the resilience of the global food system. Effective LivestockPlus approaches take one of two forms: (1) simple improvements such as new forage varieties and animal management practices that spread from farmer to farmer by word of mouth, or (2) complex sets of new practices that integrate forage production more closely into farms’ other agricultural activities and agro-ecologies.  相似文献   
992.
993.
In situ metal stabilisation by amendments has been demonstrated as an appealing low-cost remediation strategy for contaminated soil. This study investigated the short-term leaching behaviour and long-term stability of As and Cu in soil amended with coal fly ash and/or green waste compost. Locally abundant inorganic (limestone and bentonite) and carbonaceous (lignite) resources were also studied for comparison. Column leaching experiments revealed that coal fly ash outperformed limestone and bentonite amendments for As stabilisation. It also maintained the As stability under continuous leaching of acidic solution, which was potentially attributed to high-affinity adsorption, co-precipitation, and pozzolanic reaction of coal fly ash. However, Cu leaching in the column experiments could not be mitigated by any of these inorganic amendments, suggesting the need for co-addition of carbonaceous materials that provides strong chelation with oxygen-containing functional groups for Cu stabilisation. Green waste compost suppressed the Cu leaching more effectively than lignite due to the difference in chemical composition and dissolved organic matter. After 9-month soil incubation, coal fly ash was able to minimise the concentrations of As and Cu in the soil solution without the addition of carbonaceous materials. Nevertheless, leachability tests suggested that the provision of green waste compost and lignite augmented the simultaneous reduction of As and Cu leachability in a fairly aggressive leaching environment. These results highlight the importance of assessing stability and remobilisation of sequestered metals under varying environmental conditions for ensuring a plausible and enduring soil stabilisation.  相似文献   
994.
The disposal of hazardous crude oil tank bottom sludge (COTBS) represents a significant waste management burden for South Mediterranean countries. Currently, the application of biological systems (bioremediation) for the treatment of COTBS is not widely practiced in these countries. Therefore, this study aims to develop the potential for bioremediation in this region through assessment of the abilities of indigenous hydrocarbonoclastic microorganisms from Libyan Hamada COTBS for the biotreatment of Libyan COTBS-contaminated environments. Bacteria were isolated from COTBS, COTBS-contaminated soil, treated COTBS-contaminated soil, and uncontaminated soil using Bushnell Hass medium amended with Hamada crude oil (1 %) as the main carbon source. Overall, 49 bacterial phenotypes were detected, and their individual abilities to degrade Hamada crude and selected COBTS fractions (naphthalene, phenanthrene, eicosane, octadecane and hexane) were evaluated using MT2 Biolog plates. Analyses using average well colour development showed that ~90 % of bacterial isolates were capable of utilizing representative aromatic fractions compared to 51 % utilization of representative aliphatics. Interestingly, more hydrocarbonoclastic isolates were obtained from treated contaminated soils (42.9 %) than from COTBS (26.5 %) or COTBS-contaminated (30.6 %) and control (0 %) soils. Hierarchical cluster analysis (HCA) separated the isolates into two clusters with microorganisms in cluster 2 being 1.7- to 5-fold better at hydrocarbon degradation than those in cluster 1. Cluster 2 isolates belonged to the putative hydrocarbon-degrading genera; Pseudomonas, Bacillus, Arthrobacter and Brevundimonas with 57 % of these isolates being obtained from treated COTBS-contaminated soil. Overall, this study demonstrates that the potential for PAH degradation exists for the bioremediation of Hamada COTBS-contaminated environments in Libya. This represents the first report on the isolation of hydrocarbonoclastic bacteria from Libyan COTBS and COTBS-contaminated soil.  相似文献   
995.
A survey of academic programs in air pollution control was made. Results from the 127 schools reporting are tabulated by state. Faculty involved in air pollution instruction are identified. Some conclusions and recommendations are presented.  相似文献   
996.
The U.S. Environmental Protection Agency (EPA), in cooperation with the Toronto Harbour Commissioners (THC), conducted a Superfund Innovative Technology Evaluation (SITE) demonstration of the THC Soil Recycle Treatment Train. The treatment train consists of three technologies operated in sequence: a soil wash process, a metals removal process, and a biological treatment process. The THC conducted an extensive demonstration of the treatment train at a 55 tons per day pilot plant in order to evaluate an approach for remediation of industrial/commercial sites that are situated in the Toronto Port Industrial District (PID). Three soils were processed during the THC demonstration. The EPA SITE demonstration project examined, in detail, soil processing from one of the sites being evaluated as part of the overall THC project. Contaminants included organic compounds and heavy metals. It has been estimated by THC that as much as 2,200,000 tons of soil from locations within the PID may require some form of treatment due to heavy metal and/or organic contamination that resulted from various industrial processing operations. The objective of the SITE demonstration was to evaluate the technical effectiveness of the process in relation to THC’s target criteria.

Gravel and sand that met the THC target criteria for medium to fine soil suitable for industrial/commercial sites was produced. The fine soil from the biological treatment process did not meet the target level of 2.4 ppm for benzo(a)pyrene. However, there was a significant reduction in polynuclear aromatic hydrocarbon (PAH) compounds. The metals removal process achieved reductions of greater than seventy percent for copper, lead, nickel, and zinc.  相似文献   
997.
998.
On June 18, 19, and 20, 1970, two aircraft, a rawinsonde, two pibal stations, and four ground stations provided simultaneous samples of total oxidant, temperature, and winds up to 8000 ft in an area extending from Santa Monica, Calif., east to Redlands and north across the San Bernardino Mountains. It was shown that photochemical oxidant formed in the marine layer is vented up the slopes and over the crest of the San Bernardino Mountains during the day. Layers of high oxidant concentrations were detected above the inversion base, suggesting that some pollution is vented up the slopes and subsequently advected back to the south. The diurnal changes in the temperature inversion also contribute to the high concentration found above the inversion base. These processes result in multi-layers of pollution. The study suggests that oxidant air pollution is transported up to 80 mi to forested mountains, where severe damage to conifer species has been documented.  相似文献   
999.
Regional Goals     
As a representative of EPA in the role of the Regional Administrator, I frequently feel like a middle man between the idealistic goals and timetables of the Congress and the practical problems of the states and local agencies in implementing air pollution control. As many of you know, EPA is one of the most decentralized of the federal agencies. Regional offices of EPA have much more authority to initiate action programs and allocate funds than do regional offices of HEW, HUD, or almost any other federal agency. This strong regional approach has sometimes been criticized as antithetical to a unified national approach to environmental policy. It has been said that you can’t run a national air program with ten idi-osyncracies. I disagree. I believe it is difficult or impossible to develop a program legislatively or administratively which is nationally uniform and yet recognizes the idiosyncracies of local situations and needs.  相似文献   
1000.
A stepwise multiple regression procedure was employed to develop the best .fit equation relating maximum afternoon ozone concentrations to meteorological and emission factors along a 24h upwind air parcel trajectory. The equation was developed using ozone data from receptor sites in Northern New Jersey and the resulting correlation coefficient was 0.96. The four most significant variables were the upwind ozone maximum on the previous day, today’s maximum temperature, the previous day’s upwind maximum temperature and the mean wind speed from the surface to 1000 m. The model was also successfully tested at 5 other sites in the Northeastern Quadrant of the United States. The results indicate that the model could be a potentially useful tool for air pollution forecasters in predicting maximum ozone concentrations in this quadrant of the country.  相似文献   
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