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961.
Getahun T Mengistie E Haddis A Wasie F Alemayehu E Dadi D Van Gerven T Van der Bruggen B 《Environmental monitoring and assessment》2012,184(10):6337-6345
As one of cities in the developing countries, a rapid population growth and industrial activities pose many environmental challenges for Jimma city, Ethiopia. One aspect of urban growth posing a threat on sustainable development is poor solid waste management, which results in environmental pollution. The purpose of this study is to evaluate the quantity, composition, sources of waste generated, their current disposal practices, and to recommend appropriate management technologies. The total waste generated daily in Jimma city was ca. 88,000 kg, and the average per capita generation rate was 0.55?±?0.17 kg/capita/day. Eighty-seven percent of the waste was produced by households and 13% by institutions, and a negligible fraction (0.1%) was generated by street sweepings. During the rainy season, 40% more waste was generated than in the dry season because of the increased availability of agricultural food product. Further analysis showed that biodegradable organic waste constitutes 54% by weight with an average moisture content of 60% that falls within the required limits for composting. The nonbiodegradable components constitute 46% of which 30% of it was nonrecyclable material. Only 25% of the community uses municipal containers for disposal at the selected landfill site. Fifty-one percent of the households disposed their waste in individually chosen spots, whereas 22% burned their waste. Finally 2% of households use private waste collectors. The socioeconomic analysis showed that higher family income and educational status is associated more with private or municipal waste collection and less with the application of backyard or open dumping. These insights into generated waste and management practice in Jimma city allow making suggestions for improved collection, treatment, and disposal methods. A primary conclusion is that the biodegradable waste is a major fraction having suitable properties for recycling. As such an economic benefit can be obtained from this waste while avoiding the need for disposal. 相似文献
962.
Chrastný V Vaněk A Teper L Cabala J Procházka J Pechar L Drahota P Penížek V Komárek M Novák M 《Environmental monitoring and assessment》2012,184(4):2517-2536
The soils adjacent to an area of historical mining, ore processing and smelting activities reflects the historical background
and a mixing of recent contamination sources. The main anthropogenic sources of metals can be connected with historical and
recent mine wastes, direct atmospheric deposition from mining and smelting processes and dust particles originating from open
tailings ponds. Contaminated agriculture and forest soil samples with mining and smelting related pollutants were collected
at different distances from the source of emission in the Pb–Zn–Ag mining area near Olkusz, Upper Silesia to (a) compare the
chemical speciation of metals in agriculture and forest soils situated at the same distance from the point source of pollution
(paired sampling design), (b) to evaluate the relationship between the distance from the polluter and the retention of the
metals in the soil, (c) to describe mineralogy transformation of anthropogenic soil particles in the soils, and (d) to assess
the effect of deposited fly ash vs. dumped mining/smelting waste on the mobility and bioavailability of metals in the soil.
Forest soils are much more affected with smelting processes than agriculture soils. However, agriculture soils suffer from
the downward metal migration more than the forest soils. The maximum concentrations of Pb, Zn, and Cd were detected in a forest
soil profile near the smelter and reached about 25 g kg − 1, 20 g kg − 1 and 200 mg kg − 1 for Pb, Zn and Cd, respectively. The metal pollutants from smelting processes are less stable under slightly alkaline soil
pH then acidic due to the metal carbonates precipitation. Metal mobility ranges in the studied forest soils are as follows:
Pb > Zn ≈ Cd for relatively circum-neutral soil pH (near the smelter), Cd > Zn > Pb for acidic soils (further from the smelter).
Under relatively comparable pH conditions, the main soil properties influencing metal migration are total organic carbon and
cation exchange capacity. The mobilization of Pb, Zn and Cd in soils depends on the persistence of the metal-containing particles
in the atmosphere; the longer the time, the more abundant the stable forms. The dumped mining/smelting waste is less risk
of easily mobilizable metal forms, however, downward metal migration especially due to the periodical leaching of the waste
was observed. 相似文献
963.
K. Mwila M. H. Burton J. S. Van Dyk B. I. Pletschke 《Environmental monitoring and assessment》2013,185(3):2315-2327
Organophosphate (OP) and carbamate (CP) pesticides act by the inhibition of acetylcholinesterase (AChE). This enables the use of this enzyme for the detection of these pesticides in the environment. While many studies have looked at the effect of single pesticides on AChE, the effect of mixtures of pesticides still requires extensive investigation. This is important to evaluate the cumulative risk in the case of simultaneous exposure to multiple pesticides. Therefore we examined the effect of five different pesticides (carbaryl, carbofuran, parathion, demeton-S-methyl, and aldicarb) on AChE activity to determine whether combinations had an additive, synergistic, or antagonistic inhibitory effect. Results indicated that the mixtures had an additive inhibitory effect on AChE activity. The data from the assays of the mixtures were used to develop and train an artificial neural network (ANN) which was then utilised successfully for the identification of pesticides and their concentrations in mixtures. This study is significant because it evaluated mixtures of OPs and CPs where previous studies focused on either OPs or CPs. Previous studies have only examined up to three pesticides while this study evaluated mixtures of five pesticides simultaneously. This is also the first study where an ANN was able to utilise data from the inhibition of a single enzyme to differentiate five different pesticides and their concentrations from mixtures. 相似文献
964.
Karen Van de Vel Clemens Mensink Koen De Ridder Felix Deutsch Joachim Maes Jo Vliegen Artash Aloyan Alexander Yermakov Vardan Arutyunyan Tamara Khodzher Bas Mijling 《Environmental monitoring and assessment》2010,165(1-4):665-674
In this paper, we assess the status of the air quality in the Lake Baikal region which is strongly influenced by the presence of anthropogenic pollution sources. We combined the local data, with global databases, remote sensing imagery and modelling tools. This approach allows to inventorise the air-polluting sources and to quantify the air-quality concentration levels in the Lake Baikal region to a reasonable level, despite the fact that local data are scarcely available. In the simulations, we focus on the month of July 2003, as for this period, validation data are available for a number of ground-based measurement stations within the Lake Baikal region. 相似文献
965.
José Luis Iriarte Silvio Pantoja Humberto E. González Gabriela Silva Hector Paves Pamela Labbé Lorena Rebolledo Murat Van Ardelan V. Häussermann 《Environmental monitoring and assessment》2013,185(6):5055-5070
Anthropogenic (aquaculture) changes in environment nutrient concentrations may affect phytoplankton (biomass and taxa composition) in marine coastal waters off the Chilean Patagonia. The effects of adding nitrate (NO3 ?) to natural phytoplankton assemblages were evaluated considering biomass, cell abundance, and taxonomic composition. Microcosm experiments were performed in the spring, summer, and winter in the Comau Fjord located in Subantarctic Patagonia. At the end of the experiments, NO3 ? decreased rapidly and was undetectable in treatments, indicating a strong NO3 ? deficiency associated with an exponential increase in Chl-a concentrations, particulate organic nitrogen, and carbon in these treatments. Moreover, given the depleted nitrate concentrations of the spring and summer experiments, the micro-phytoplankton taxa structure shifted from mixed diatom and dinoflagellate assemblages (Ceratium spp., Dinophysis spp., Coscinodiscus sp., Rhizosolenia pungens) to assemblages dominated by blooms of the classic chain-forming diatoms found in temperate and cold waters such as Chaetoceros spp., Skeletonema spp., and Thalassiosira spp. Thus, nitrogen sources (i.e., nitrate, ammonia) may influence phytoplankton abundance and biomass accumulation dynamics in the northern section of Patagonia. It also emphasizes the importance of diatom taxa in regards to the short-term response of phytoplankton to changing environmental nutrient conditions due to natural (decreasing freshwater stream flow) and anthropogenic (aquaculture) events. This situation may be one of the future scenarios in the Patagonian fjords, thus stressing the needs for active environmental monitoring and impact assessment. 相似文献
966.
Daniellys Alejo Mayra C. Morales Jorge B. de la Torre Ricardo Grau László Bencs René Van Grieken Piet Van Espen Dismey Sosa Vladimir Nuñez 《Environmental monitoring and assessment》2013,185(7):6023-6033
Atmospheric nitrogen dioxide (NO2) and sulfur dioxide (SO2) levels were monitored simultaneously by means of Radiello passive samplers at six sites of Santa Clara city, Cuba, in the cold and the warm seasons in 2010. The dissolved ionic forms of NO2 and SO2 as nitrate and sulfite plus sulfate, respectively, were determined by means of ion chromatography. Analysis of NO2 as nitrite was also performed by UV–Vis spectrophotometry. For NO2, significant t tests show good agreement between the results of IC and UV–Vis methods. The NO2 and SO2 concentrations peaked in the cold season, while their minimum levels were experienced in the warm season. The pollutant levels do not exceed the maximum allowable limit of the Cuban Standard 39:1999, i.e., 40 μg/m3 and 50 μg/m3 for NO2 and SO2, respectively. The lowest pollutant concentrations obtained in the warm season can be attributed to an increase in their removal via precipitation (scavenging) while to the decreased traffic density and industrial emission during the summer holidays (e.g., July and August). 相似文献
967.
Rouzbeh Tehrani Monica M. Lyv Benoit Van Aken 《Environmental science and pollution research international》2014,21(10):6346-6353
The polychlorinated biphenyl (PCB)-degrading bacterium, Burkholderia xenovorans LB400, was capable of transforming three hydroxylated derivatives of 2,5-dichlorobiphenyl (2,5-DCB) (2′-hydroxy- (2′-OH-), 3′-OH-, and 4′-OH-2,5-DCB) when biphenyl was used as the carbon source (i.e., biphenyl pathway-inducing condition), although only 2′-OH-2,5-DCB was transformed when the bacterium was growing on succinate (i.e., condition non-inductive of the biphenyl pathway). On the contrary, hydroyxlated derivatives of 2,4,6-trichlorobiphenyl (2,4,6-TCB) (2′-OH-, 3′-OH-, and 4′-OH-2,4,6-TCB) were not significantly transformed by B. xenovorans LB400, regardless of the carbon source used. Gene expression analyses showed a clear correlation between the transformation of OH-2,5-DCBs and expression of genes of the biphenyl pathway. The PCB metabolite, 2,5-dichlorobenzoic acid (2,5-DCBA), was produced following the transformation of OH-2,5-DCBs. 2,5-DCBA was not further transformed by B. xenovorans LB400. The present study is significant because it provides evidence that PCB-degrading bacteria are capable of transforming hydroxylated derivatives of PCBs, which are increasingly considered as a new class of environmental contaminants. 相似文献
968.
969.
Stanley Karanja Ng’ang’a Mark T. Van Wijk Mariana C. Rufino Ken E. Giller 《Regional Environmental Change》2016,16(8):2317-2330
Livestock production is very risky due to climate variability in semi-arid Sub-Saharan Africa. Using data collected from 400 households in the Borena zone of the Oromia Region, we explored what drives adoption of agricultural practices that can decrease the vulnerability of agro-pastoralists to climate change. Households with more adaptive capacity adopted a larger number of practices. The households’ adaptive capacity was stronger when the quality of local institutions was high. However, adaptive capacity had less explanatory power in explaining adoption of adaptation options than household socio-economic characteristics, suggesting that aggregating information into one indicator of adaptive capacity for site-specific studies may not help to explain the adoption behaviour of households. Strong local institutions lead to changes in key household-level characteristics (like membership to community groups, years lived in a village, access to credit, financial savings and crop income) which positively affect adoption of agricultural practices. In addition, better local institutions were also positively related to adoption of livestock-related adaptation practices. Poor access to a tarmac road was positively related to intensification and diversification of crop production, whereas it was negatively related to the intensification of livestock production, an important activity for generating cash in the region. Our findings suggest that better local institutions lead to changes in household characteristics, which positively affect adoption of adaptation practices, suggesting that policies should aim to strengthen local institutions. 相似文献
970.