Recycling and reuse of waste such as building rubble, concrete lumps, etc. generated at construction and demolition sites form part of a wider, complex issue, primarily relating to improving supplies of construction material and solving problems of disposal of waste construction material. Within the framework of the sustainable development of the environment, the use of waste materials with minimum environmental impact has received much attention. The conversion of a large amount of demolished waste into an alternative resource will conserve the depleting natural resources of building materials. Demolished waste is mainly used as a non-stabilized base or sub-base in highway construction. The present paper discusses the recycling process and makes an effort to assess a safe and economic use of recycled concrete as a structural grade material for the construction industry. Extensive tests of structural properties such as compressive strength, flexural strength and split tensile strength of recycled concrete were carried out, in which cement and similarly fine aggregate were partially replaced by demolished waste to obtain recycled concrete and recycled aggregate concrete whose properties were compared with results for the conventional concrete. 相似文献
Environmental Science and Pollution Research - Methanol intoxication is a global problem with serious morbidities and mortalities. Apart from the lifelong disabilities experienced by methanol... 相似文献
Environmental Science and Pollution Research - Because of health concerns regarding the presence of enteric viruses in wastewater effluents, this study was designed to investigate the occurrence of... 相似文献
Pathways for achieving the 1.5–2 °C global temperature moderation target imply a massive scaling of carbon dioxide (CO2) removal technologies, in particular in the 2040s and onwards. CO2 direct air capture (DAC) is among the most promising negative emission technologies (NETs). The energy demands for low-temperature solid-sorbent DAC are mainly heat at around 100 °C and electricity, which lead to sustainably operated DAC systems based on low-cost renewable electricity and heat pumps for the heat supply. This analysis is carried out for the case of the Maghreb region, which enjoys abundantly available low-cost renewable energy resources. The energy transition results for the Maghreb region lead to a solar photovoltaic (PV)-dominated energy supply with some wind energy contribution. DAC systems will need the same energy supply structure. The research investigates the levelised cost of CO2 DAC (LCOD) in high spatial resolution and is based on full hourly modelling for the Maghreb region. The key results are LCOD of about 55 €/tCO2 in 2050 with a further cost reduction potential of up to 50%. The area demand is considered and concluded to be negligible. Major conclusions for CO2 removal as a new energy sector are drawn. Key options for a global climate change mitigation strategy are first an energy transition towards renewable energy and second NETs for achieving the targets of the Paris Agreement.
Biochar is produced from the pyrolysis of carbon-rich plant- and animal-residues under low oxygen and high temperature conditions and has been increasingly used for its positive role in soil compartmentalization through activities such as carbon sequestration and improving soil quality. Biochar is also considered a unique adsorbent due to its high specific surface area and highly carbonaceous nature. Therefore, soil amendments with small amounts of biochar could result in higher adsorption and, consequently, decrease the bioavailability of contaminants to microbial communities, plants, earthworms, and other organisms in the soil. However, the mechanisms affecting the environmental fate and behavior of organic contaminants, especially pesticides in biochar-amended soil, are not well understood. The purpose of this work is to review the role of biochar in primary processes, such as adsorption–desorption and leaching of pesticides. Biochar has demonstrable effects on the fate and effects of pesticides and has been shown to affect the degradation and bioavailability of pesticides for living organisms. Moreover, some key aspects of agricultural and environmental applications of biochar are highlighted. 相似文献
Journal of Material Cycles and Waste Management - The hydrolysis of organic waste in anaerobic digestion is slow and time-consuming. Pretreatment of the waste can potentially improve hydrolysis and... 相似文献
This paper analyzes livelihood change and livelihood sustainability of households in the upland part of the Lembang subwatershed,
West Sumatra, in response to changes in the natural resource management context during the last decade. Using the sustainable
livelihood framework (SLF), we measured livelihood changes at two separate points in time, 1996 and 2006, and assessed their
environmental, economic, social, and institutional sustainability. We found that people with a low income had less access
to capital assets than people from middle- and high-income groups. Our analysis revealed, however, that access to capital
assets increased over time, and that poor households experienced economic improvement, indicating an overall increase in economic
sustainability. Environmental sustainability, however, is threatened by intensive agricultural practices such as high agrochemical
input and intensive soil tillage on steep slopes, leading to pollution and soil erosion. Social sustainability is also a matter
of concern: while social exclusion has been reduced, income inequity has increased. Institutional sustainability is likely
to remain uncertain, as local institutions for natural resource management are still weak, despite the fact that decentralization
has been implemented during the last 8 years. External facilitation is needed to improve the livelihood of upland people while,
at the same time, enhancing the sustainability of watershed management. Strengthening local institutions, conserving natural
resources, and promoting environmentally sound agricultural practices are the three most important policies to be promoted
within the watershed. 相似文献