77 research outputs found
The importance of agroforestry hay and walnut production in the walnut-fruit forests of southern Kyrgyzstan
Walnut-fruit forests (WFF) in Kyrgyzstan are biodiversity hotspots, provide important ecosystem services, and are of economic value yet currently suffer from a lack of sustainable management. We analysed current agroforestry practices through a series of interviews with farmers and reviewed the input-output data for 5years of hay and walnut production for three case studies. The interviews showed that hay-making and walnut collection are the primary agroforestry practices in the WFF and have clear economic importance. Walnut in particular is a source of additional income for farmers and hay-making activities are strongly influenced by the need to winter cattle in these regions. The low reliability of interview data limited the planned analysis of profitability of case studies. Walnut production, however, is difficult to calculate because it is highly dependent on weather conditions and cropping practices between walnut trees (Juglans regia L.). This study highlights the need for improved agroforestry technologies in the WFF and identifies potential means for a sustainable, multi-purpose management of the WFF with a special focus on income generatio
Human Impacts on Forest Biodiversity in Protected Walnut-Fruit Forests in Kyrgyzstan
We used a spatially explicit model of forest dynamics, supported by empirical field data and socioeconomic data, to examine the impacts of human disturbances on a protected forest landscape in Kyrgyzstan. Local use of 27 fruit and nut species was recorded and modeled. Results indicated that in the presence of fuelwood cutting with or without grazing, species of high socioeconomic impor- tance such as Juglans regia, Malus spp., and Armeniaca vulgaris were largely eliminated from the landscape after 50–150 yr. In the absence of disturbance or in the presence of grazing only, decline of these species occurred at a much lower rate, owing to competi- tive interactions between tree species. This suggests that the current intensity of fuelwood harvesting is not sustainable. Conversely, cur- rent grazing intensities were found to have relatively little impact on forest structure and composition, and could potentially play a positive role in supporting regeneration of tree species. These results indicate that both positive and negative impacts on biodiversity can arise from human populations living within a protected area. Potentially, these could be reconciled through the development of participatory approaches to conservation management within this reserve, to ensure the maintenance of its high conservation value while meeting human needs
Different Behavior of Enteric Bacteria and Viruses in Clay and Sandy Soils after Biofertilization with Swine Digestate
Enteric pathogens from biofertilizer can accumulate in the soil, subsequently
contaminating water and crops. We evaluated the survival, percolation and leaching
of model enteric pathogens in clay and sandy soils after biofertilization with
swine digestate: PhiX-174, mengovirus (vMC0), Salmonella enterica Typhimurium and
Escherichia coli O157:H7 were used as biomarkers. The survival of vMC0 and PhiX-174
in clay soil was significantly lower than in sandy soil (ıPT90 values of 10.520 0.600
vs. 21.270 1.100 and 12.040 0.010 vs. 43.470 1.300, respectively) and PhiX-
174 showed faster percolation and leaching in sandy soil than clay soil (ıPT90 values of
0.46 and 2.43, respectively). S. enterica Typhimurium was percolated and inactivated
more slowly than E. coli O157:H7 (ıPT90 values of 9.340 0.200 vs. 6.620 0.500
and 11.900 0.900 vs. 10.750 0.900 in clay and sandy soils, respectively), such
that E. coli O157:H7 was transferred more quickly to the deeper layers of both soils
evaluated (percolation). Our findings suggest that E. coli O157:H7 may serve as a useful
microbial biomarker of depth contamination and leaching in clay and sandy soil and that
bacteriophage could be used as an indicator of enteric pathogen persistence. Our study
contributes to development of predictive models for enteric pathogen behavior in soils,
and for potential water and food contamination associated with biofertilization, useful for
risk management and mitigation in swine digestate recycling.RTA2014-00024-C04-01 from the Spanish Ministry of Economy and Innovation
and the Brazilian CNPq Project number 472804/2013-8, an dby CAPES/PNPD and CAPES/PDSE
Changes in microbiological composition of soils and soil contamination with drug-resistant bacteria caused by the use of sewage sludge in nature
This study evaluated the effect of the use of sewage sludge in nature on biological soil parameters. The study was conducted is field experiment environment (small beds). The sandy soil was fertilized with sewage sludge dried naturally (in heaps) and in solar drying facilities. The fertilization was based on the doses of sewage sludge and manure with the amounts of 10, 20, 30 and 40 Mg/ha. The experiment duration was 3 years. The sanitary status of the soils fertilized with the sludge and manure was evaluated (coliform index, Clostridium perfrinens). Furthermore, the content of pathogenic bacteria was evaluated, with determination of its resistance to first-line antibiotics
DOPUNJAVANJE KRUTE FRAKCIJE TEKUĆEG GNOJA SVINJA PRIRODNIM ZEOLITIMA I NJIHOV UTJECAJ NA POHRANJENE SUBSTRATE
Including Pathogen Risk in Life Cycle Assessment of Wastewater Management. 1. Estimating the Burden of Disease Associated with Pathogens
The environmental performance of wastewater and sewage sludge management is commonly assessed using life cycle assessment (LCA), whereas pathogen risk is evaluated with quantitative microbial risk assessment (QMRA). This study explored the application of QMRA methodology with intent to include pathogen risk in LCA and facilitate a comparison with other potential impacts on human health considered in LCA. Pathogen risk was estimated for a model wastewater treatment system (WWTS) located in an industrialized country and consisting of primary, secondary, and tertiary wastewater treatment, anaerobic sludge digestion, and land application of sewage sludge. The estimation was based on eight previous QMRA studies as well as parameter values taken from the literature. A total pathogen risk (expressed as burden of disease) on the order of 0.2–9 disability-adjusted life years (DALY) per year of operation was estimated for the model WWTS serving 28 600 persons and for the pathogens and exposure pathways included in this study. The comparison of pathogen risk with other potential impacts on human health considered in LCA is detailed in part 2 of this article series
Extended spectrum beta-lactamases in <i>Escherichia coli</i> from municipal wastewater
Introduction and objective
Over the past decades, awareness of the environmental load of resistant organisms has increased. The presented paper focuses on antibiotic resistance and detection of resistance genes in environmental E. coli and on the evaluation of biofilm formation in ESBLs (extended spectrum beta-lactamase) producing E. coli isolated from an urban wastewater treatment plant.
Material and Methods
Wastewater samples and artificially added polystyrene pellets were used as the source for E. coli isolation. Minimal inhibitory concentrations of 19 antibiotics were determined according to CLSI (2013). Biofilm formation was investigated by crystal violet or resazurin methods. CTX-M, carbapenemases, qnrS, mobile elements and virulence factors were determined by PCR. Clonal relatedness of strains was detected by principal component analysis by a Maldi biotyper.
Results
ESBL phenotype was detected in 26% of environmental strains. CTX-M, CMY-2 and qnrS genes of antibiotic resistance were detected. IMP gene together with integron 1 in one ertapenem resistant E. coli was also recorded. There was no evident correlation between antibiotic resistance, virulence and biofilm production.
Conclusions
Conclusions. The results showed that the wastewater is a source of ESBLs, carbapenemases and plasmid fluoroquinolone resistance. Strains with biofilm production, antibiotic resistance of CTX-M group, CMY-2, qnrS genes and virulence factors present a potential environmental health risk
Evaluation of physical, chemical and heavy metal concentration of food waste composting
In this study, food waste composting with rice husk and coconut fibre as compost medium were carried out. Two types of different fermentation liquids were prepared which were fermented liquid (banana peel) and fermented liquid from fermented soybeans. During the composting process, a compost samples for a twenty week duration at an interval time of two weeks. Among the physico-chemical parameters that were tested were temperature, moisture content, pH value, Total Nitrogen, Total Phosphorous, Potassium and Total Organic Carbon and Carbon Nitrogen ratio. Heavy metals such as copper, cadmium, lead, nickel and arsenic were observed and analysed. From this study, it was found that, the temperature increased during the thermophilic phase while there was gradually increase of Total Nitrogen, Total Phosphorous and Potassium from the beginning till the end of the composting process. It was also found that the total organic carbon (TOC) and the carbon nitrogen ratio decreased significantly during the decomposition process. Traces amounts of heavy metals were also detected and remains below the standard Malaysian Environmental regulations. It was concluded that, the composting process was faster with processed food waste followed by combination of processed food waste and raw. Raw food waste were demonstrated the lowest degradation rate
Co-composting: An Opportunity to Produce Compost with Designated Tailor-Made Properties
AbstractCo-composting is a technique that allows the aerobic degradation of organic waste mixtures, primarily aiming at obtaining compost that can be used as fertiliser or soil amendment. As compared to the typical composting activity, the main difference is not merely the use of more than one feedstock to start and sustain the biodegradation process, but also the possibility of combining various kinds of waste to obtain 'tailored' products with designed properties, or to reclaim and valorise natural resources, such as degraded soils or polluted soils and sediments. Set up of appropriate co-composting protocols can be a way to optimise the management of waste produced by different sectors of agriculture and industry and also from human settlements. Different formulations can not only optimise the biodegradation process through the adjustment of nutrient ratios, but also lead to the formation of products with innovative properties. Moreover, co-composting can be a technique of choice for the reclamation of soils degraded by intensive agriculture or contaminated soils and sediments. In fact, an appropriate mix of organic waste and soils can restore the soil structure and induce fertility in nutrient-depleted soils, and also remediate polluted soils and sediments through degradation of organic pollutants and stabilisation of heavy metals. While the selection of different mixes of organic waste may lead to the design of composts with specific properties and the potential valorisation of selected waste materials, there are still several factors that hamper the development of co-composting platforms, mainly insufficient knowledge of some chemical and microbiological processes, but also some legislative aspects. This chapter illustrates the progress achieved in co-composting technology worldwide, some key legislative aspects related to the co-composting process, the main scientific and technical aspects that deserve research attention to further develop co-composting technology, and successful applications of co-composting for the reclamation of soils and sediments, allowing their use for cultivation or as growing media in plant nurseries. A specific case study of the production of fertile plant-growing media from sediment co-composting with green waste is also illustrated
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