Environmental Science
M. Piri; E. Sepehr
Abstract
BACKGROUND AND OBJECTIVES: Phosphorus is an essential and limiting nutrient for all living organisms. Although phosphorus is a finite resource on earth, it is usually wasted today. Precipitation of struvite from waste residues is mainly carried out to recover phosphorus. This study aimed to investigate ...
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BACKGROUND AND OBJECTIVES: Phosphorus is an essential and limiting nutrient for all living organisms. Although phosphorus is a finite resource on earth, it is usually wasted today. Precipitation of struvite from waste residues is mainly carried out to recover phosphorus. This study aimed to investigate the percentage of phosphorous recovery from sewage sludge in the presence of grape-biochar via the formation of biochar/struvite precipitates. METHODS: Different amounts of grape-biochar were applied to recover nutrients (phosphorus, nitrogen, and magnesium) from sewage sludge via the formation of struvite by digestion of sewage sludge with H2SO4 and the molar ratio of magnesium/ ammonium/ phosphorus in 2:1:1 at pH=8.5. Solubility and release properties of the precipitates were determined and the equations, such as first-order, parabolic diffusion, power function, and simple Elovich models, were fitted to the kinetic data.FINDINGS: The phosphorus recovery from sewage sludge increased by application of grape biochar in the precipitation system, and the accumulation release of nutrients (phosphorus, nitrogen, and magnesium) from samples increased in the presence of grape biochar, especially in high amounts. Increasing the remove and recovery of phosphorus from sewage sludge by application of grape-biochar decreased the incidence of eutrophication, as an environmental dilemma, and provided the requirement for phosphorus-fertilizers by solid waste management. The solubility of the samples was 0.5 mole per liter hydrochloric acid > in 20 gram per liter citric acid > water. The results showed that the phosphorus - cumulative - release of composites in water good fitted the parabolic kinetic model (R2=0.97-0.99), whereas it followed the simple Elovich model (R2=0.86-0.92) in 0.5 mole per liter hydrochloric acid and first-order kinetics model (R2=0.76-0.92) in 20 gram per liter critic acid.CONCLUSION: The results indicated that the presence of grape-biochar for recovery of phosphorus from sludge as struvite had a good potential for increasing the release of nutrients for the formation of struvite, and these precipitates had a high potential to be used as a slow-release phosphorus-fertilizer.
Environmental Management
A.A. Shayesteh; O. Koohshekan; F. Khadivpour; M. Kian; R. Ghasemzadeh; M. Pazoki
Abstract
Due to the growth of population and industrialization, a great number of problems associated with producing industrial wastes have been created for both the environment and human beings. The industrial waste management in Brujen industrial park, located in the western part of Iran, has been investigated ...
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Due to the growth of population and industrialization, a great number of problems associated with producing industrial wastes have been created for both the environment and human beings. The industrial waste management in Brujen industrial park, located in the western part of Iran, has been investigated in this study using the environmental rapid impact assessment matrix technique. For this purpose, the effective activities and components were classified. The determination of the best scenarios with the least impact on the environment was performed by developing the scenarios for possible industrial waste disposal and making calculations by the rapid impact assessment matrix method. The components of the environment were first classified into physical/chemical, economic/operational, biological/ecological, and social/cultural items. Afterward, with respect to the criteria of the rapid impact assessment matrix method, the importance of environmental impacts was determined by standard scoring of the developed scenarios. Ultimately, the environmental score of each component for the scenarios was calculated using the rapid impact assessment matrix method, and the best scenario with the least environmental impacts was selected through a quantitative comparison. According to the results, scenario 3 (pyrolysis) and scenario 1 (recycling) were found to have the most negative impact and the most positive impact on the environment. Scenario 4 (incineration), with its severe air pollution, obtained a high negative score and was excluded from the options. As a result, two systems of recycling (scenario 1) and the sanitary landfill (scenario 2) were identified as complementary to each other and were selected as a solid waste management method.
B. Gwada; G. Ogendi; S.M. Makindi; S. Trott
Abstract
Among the emerging environmental issues within Sub-Saharan Africa is the haphazard disposal of plastic waste, some of which end up downstream in the marine environment leading to negative effects. Notably there have been cases of humpback whales getting entangled in ‘ghost’ fishing nets, ...
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Among the emerging environmental issues within Sub-Saharan Africa is the haphazard disposal of plastic waste, some of which end up downstream in the marine environment leading to negative effects. Notably there have been cases of humpback whales getting entangled in ‘ghost’ fishing nets, and endangered turtles ingesting plastic wastes in Watamu beach in Kenya. The aim of the current study was to assess the composition and management of plastic waste discarded by households in Watamu ward. Stratified random sampling was used to collect data from households in four sub-locations within Watamu ward. Data were analysed using descriptive and inferential statistics (the Freeman-Halton extension of the Fisher’s Exact test). The composition of plastics usually discarded as waste by households in order of dominance were low density polyethylene, polyethylene terephthalate, high density polyethylene and polypropylene (FH=37.959, p = 0.000). From the results, only 0.7% of respondents recycled their plastic waste. The most preferred disposal method of household plastic waste was open dumpsites (61.4%) followed by burning (12.9%) and discards (6.4%). Majority of respondents (93.6%), re-use some plastic containers for food, water, and oil storage. There was a significant difference in terms of how the respondents re-used their plastic waste in the four sub-locations (FH=36.437, p=0.005). In conclusion, the current plastic waste disposal methods at Watamu are not environmentally friendly and recycling is still at a smaller scale despite its potential to generate income and clean the environment, and promote ecosystem services and human wellbeing.
Environmental Management
V. Pelitli; Ö. Doğan; H.J. Köroğlu
Abstract
In accordance with waste strategy for Turkey, the study was carried out to analyses waste engine crankcase oils and waste gearbox oils generated from vehicle maintenance services in order to determine their suitability for recycling, recovery or final disposal based on regulation published by Turkish ...
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In accordance with waste strategy for Turkey, the study was carried out to analyses waste engine crankcase oils and waste gearbox oils generated from vehicle maintenance services in order to determine their suitability for recycling, recovery or final disposal based on regulation published by Turkish Ministry of Environment and Forestry on 21 January 2004. The regulation requires all waste oil neither abandoned nor released into the environment and all batches must be analyzed for arsenic, cadmium, chromium, lead, chlorine, total halogens, polychlorinated biphenyls, and flash points. The content analysis showed that the heavy metal concentrations in waste engine crankcase oils were varied considerably, between the metals analyzed, lead the highest is followed by chromium, arsenic and cadmium. In addition, higher amount of chlorine and total halogens, were detected in some samples, while polychlorinated biphenyls concentrations remained below regulatory limits for all samples. The analyses revealed that waste engine crankcase oils from fifteen to thirty five years old vehicles contained chromium, lead, chlorine and total halogens levels above legal limits set by Ministry of Environment and Forestry for recycling. Conversely, in comparison to the findings from the analyzed series of old vehicles, the waste engine crankcase oils samples from new vehicles and all waste gearbox oils are eligible for recycling.
