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861.
Soil contamination resulting from petroleum hydrocarbon contaminants poses a fairly substantial hazard to human health and the environment. Phytoremediation, land farming, and chemico–biological stabilization were used to treat total petroleum hydrocarbons (TPHs) and polycyclic aromatic hydrocarbons (PAHs) at a crude oil polluted soil site in Nigeria. A field pilot study was conducted by preparing nine cells with subcells attached to each serving as a control with an overall area of 1.53 m2. A complete block design method was used for the study. The prepared soil sample cells were divided into three groups with each group having approximately 300 kg of soil and delineated as low, medium, and high test plots. The low samples were spiked with 6.1 kg of crude oil, the medium samples were spiked with 12.2 kg of crudeoil, and the high samples were spiked with 18.3 kg of crude oil. Each row containing three cells with low, medium, and high concentrations were treated separately using the three treatment methods. The ratio of the soil sample to the organic amendment for the treatments was 2:1. The results showed over 90% degradation in the initial concentration of TPH and PAHs across different contaminant levels except in the control subcells where only 30% of degradation was recorded. Multivariate analysis of variance was employed to assess the significant difference in each treatment group while inferential statistics using a mean performance plot was used to ascertain the optimum treatment method. Land farming, chemico–biological stabilization, and phytoremediation ranked 1, 2, and 3, respectively. In conclusion, the three treatment methods employed all degraded the contaminants (TPH and PAHs) with land farming emerging as the best method.  相似文献   
862.
Environmental Science and Pollution Research - The study used scattered literature to summarize the effects of excess Cd, As, and Pb from contaminated soils on plant secondary metabolites/bioactive...  相似文献   
863.
Journal of Material Cycles and Waste Management - Chemical Looping Combustion (CLC) of MSW could serve as a potential treatment method for the disposal of MSW and the recovery of energy because it...  相似文献   
864.
Environmental Science and Pollution Research - The distribution of emerging organic contaminants in drinking water sources in Africa is a subject with very scanty data and information. In order to...  相似文献   
865.
This study estimates the consequences of climate change on cropland with and without implementation of adaptation measures, paying special attention to the maintenance of soil organic carbon (C) stocks. We examine the possibility for regional sustainable agricultural management practice that combines both maintenance and gain in soil carbon level with profit maximization. Future scenarios of Regional Agricultural Production Systems (RAPS) were constructed for 2000–2070 based on linking the effects of global climate change, predicted change in productivity parameters for the main agricultural crops, land-use and soil database parameters. The RAPS were used to examine profitability and feasibility of alternative agricultural scenarios, based on an economic model. A number of recommendations for decision making were proposed based on an assessment of the efficiency of adaptation in animal husbandry and in the crop production sector, after analysis of current percentage of perennial grass in rotation in comparison with future economic scenarios. Figures in color are available at  相似文献   
866.
The study established waste multipliers that could be used in conjunction with the population figure of a city to estimate the quantity of solid waste generation in the developing world. Oyo, a traditional city in Nigeria was the focus of the study. Two sets of data were collected. The first was the information on the socio-economic attributes of residents obtained from 648 households through questionnaires administered using a systematic random sampling technique. The second was the measurement of waste generated in 25% of the households for a week in each of the 12 months of the year. The study established that 23.3% of the residents surveyed have educational qualifications beyond secondary school, with 51.2% engaged in occupations requiring very little or no formal education and 50.9% were in the low-income group. The daily per capita solid waste generation was 0.129 kg. The highest (9.8%) and lowest (6.5%) of the annual quantities of waste were produced in October and February, respectively. Similarly, 20.2% of the weekly generation was produced on Saturday and the 10.2% produced on Thursday was the lowest. Animal dung, which accounted for 18.0%, constituted the highest component of the total solid waste generated. The study further established that the organic component of the waste generation was 75.4%. The results of the regression analysis R2 significant at 0.001 showed that income, household size, social status, occupation, education and season of the year explained 88.8% of waste generation in Oyo. It was established that 50.90 tonnes of solid waste was generated per day in the city in 2005, and the daily generation in the year 2008 is estimated to be 55.20 tonnes. The study concluded that with an average annual population growth of 13 000 people for the town, an additional 1.3 acres of land will need to be legally acquired annually, implying that 10.92-19.68 hectares ill be required as dump site(s) over the next 20-30 years.  相似文献   
867.
As the annual use of pesticides in the United States has escalated, public health agencies have become increasingly concerned about chronic pesticide exposure. However, without reliable, accurate analytical methods for biological monitoring, low-level chronic exposures are often difficult to assess. A method for measuring simultaneously the urinary residues of as many as 20 pesticides has been significantly improved. The method uses a sample preparation which includes enzyme digestion, extraction, and chemical derivatization of the analytes. The derivatized analytes are measured by using gas chromatography coupled with isotope-dilution tandem mass spectrometry. The limits of detection of the modified method are in the high pg/L - low μg/L range, and the average coefficient of variation (CV) of the method was below 20% for most analytes, with approximately 100% accuracy in quantification. This method was used to measure the internal doses of pesticides among selected farmer applicators and their families. Definite exposure and elimination patterns (i.e., an increase in urinary analyte levels following application and then a gradual decrease to background levels) were observed among the farmer applicators and many of the family members whose crops were treated with carbaryl, dicamba, and 2,4-D esters and amines. Although the spouses of farm workers sometimes exhibited the same elimination pattern, the levels of the targeted pesticides or metabolites found in their urine were not outside the ranges found in the general U.S. population (reference range). The farmer applicators who applied the pesticides and some of their children appeared to have higher pesticide or metabolite levels in their urine than those found in the general U.S. population, but their levels were generally comparable to or lower than reported levels in other occupationally exposed individuals. These results, however, were obtained from a nonrandom sampling of farm residents specifically targeted to particular exposures who may have altered their practices because they were being observed; therefore, further study is required to determine if these results are representative of pesticide levels among residents on all farms where these pesticides are applied using the same application techniques. Using this method to measure exposure in a small nonrandom farm population allowed differentiation between overt and background exposure. In addition, the important role of reference-range information in distinguishing between various levels of environmental exposure was reaffirmed.  相似文献   
868.
An investigation was made of the sources and degree of pollution of Ogunpa lake, situated in Ibadan, Nigeria. It was shown that the lake receives a variety of waste effluents from domestic and industrial sources which discharge into the Ogunpa stream. These waste effluents have caused an odour nuisance in the lake, and little or no dissolved oxygen is present. The discharge of nutrients (N and P) to the lake has resulted in excessive growth of aquatic weeds. All these impacts on the lake have resulted in a reduced fish production. Some suggestions for the prevention of pollution and the recovery of the lake are presented.  相似文献   
869.
The effects of local-scale anthropogenic disturbance from active drilling platforms on epibenthic megafaunal abundance, diversity and assemblage pattern were examined in two west of Shetland hydrocarbon fields at 420 and 508 m water depth. These areas were selected to include a range of disturbance regimes and contrasting faunal assemblages associated with different temperature regimes. Remotely operated vehicle (ROV) video provided high-resolution megafaunal abundance and diversity data, which were related to the extent of visible disturbance from drilling spoil. These data, in conjunction with a study deeper in the Faroe-Shetland Channel, have allowed comparison of the effects of disturbance on megabenthos across a range of sites. Disturbance to megafaunal assemblages was found to be high within 50 m of the source of drill spoil and in areas where spoil was clearly visible on the seabed, with depressed abundances (Foinaven 1,900 individuals ha−1; Schiehallion 2,178 individuals ha−1) and diversity (H′ = 1.75 Foinaven; 1.12 Schiehallion) as a result of smothering effects. These effects extended to around 100 m from the source of disturbance, although this was variable, particularly with current regime and nature of drilling activity. Further from the source of disturbance, megafaunal assemblages became more typical of the background area with increased diversity (H′ = 2.02 Foinaven; 1.77 Schiehallion) and abundance (Foinaven 16,484 individuals ha−1; Schiehallion 5,477 individuals ha−1). Visible effects on megafaunal assemblages as a result of seabed drilling were limited in extent although assemblage responses were complex, being controlled by differing effects to individual species often based on their motility.  相似文献   
870.
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