Increasing production and disposal of coal fly ash （CFA） is a matter of serious environment concern. However, CFA contains various beneficial metals and mineral matters whose demand is increasing in the industrializ...Increasing production and disposal of coal fly ash （CFA） is a matter of serious environment concern. However, CFA contains various beneficial metals and mineral matters whose demand is increasing in the industrialized world, while natural supplies are diminishing. Therefore, recovery of these potential resources from CFA can be an alternative way to save mineral resources, as well as to reduce the environmental burden of CFA disposal. There are numerous methods developed for the recovery of beneficial products from CFA. Based on the US patents and journal literatures, the present review describes the recovery status and technologies of major elements such as Al, Si, Fe and Ti, and trace elements such as V, Ga, Ge, Se, Li, Mo, U, Au, Ag, Pt groups and rare earth elements （REEs） and other beneficial products such as magnetic materials, cenospheres, and unburned carbon from CFA. It also highlights the recovery efficiency and drawbacks for their extraction, and suggests future research to develop satisfactory results in terms of selective recovery and purification.展开更多
Rupa Lake is small advancing eutrophic lake covering about 115 ha of the Lekhnath Municipality in Kaski district of western Nepal. The environment around the lake has been improved over a period of 10 years. Conservat...Rupa Lake is small advancing eutrophic lake covering about 115 ha of the Lekhnath Municipality in Kaski district of western Nepal. The environment around the lake has been improved over a period of 10 years. Conservation practices were initiated by communities including the Rupa Lake Restoration and Fishery Cooperative （RLRFC）. As a result, an abundance of non-timber Forest Products （NTFP） has increased considerably. At present, 49 NTFP are available in the lake basin. Some households （HH） i.e 10% has additional income from NTFP. It is an indirect source of food security for local people. They sell NTFP products to generate income. A few households have already started farming of NTFPs. Availability of fodder and fuel wood from community forest has significantly contributed to the livelihoods of people where as wild edible fruits and vegetables have become supplementary for food security. There is yearly food security for 57% of HH with 22% having surplus food. 5% of HH has food security for less than three months where as 19% HHs have food security for more than six months. However, livelihood and nutritional security have improved by fish farming in lake. This lake is most important for the local environment and also helps eco-tourism. The study found that 92% observed the climate change in the form of a rise in temperature （〉 70% HHs）; unpredictable rainfall （〉 75% HHs）; shifting rainfall （〉 60% HHs）; phonological changes （〉 50%）. It showed that the lake supports the restoration of natural water capacity, maintain local climate and sound environment by better natural resource management for an environment friendly ecosystem.展开更多
文摘Increasing production and disposal of coal fly ash （CFA） is a matter of serious environment concern. However, CFA contains various beneficial metals and mineral matters whose demand is increasing in the industrialized world, while natural supplies are diminishing. Therefore, recovery of these potential resources from CFA can be an alternative way to save mineral resources, as well as to reduce the environmental burden of CFA disposal. There are numerous methods developed for the recovery of beneficial products from CFA. Based on the US patents and journal literatures, the present review describes the recovery status and technologies of major elements such as Al, Si, Fe and Ti, and trace elements such as V, Ga, Ge, Se, Li, Mo, U, Au, Ag, Pt groups and rare earth elements （REEs） and other beneficial products such as magnetic materials, cenospheres, and unburned carbon from CFA. It also highlights the recovery efficiency and drawbacks for their extraction, and suggests future research to develop satisfactory results in terms of selective recovery and purification.
文摘Rupa Lake is small advancing eutrophic lake covering about 115 ha of the Lekhnath Municipality in Kaski district of western Nepal. The environment around the lake has been improved over a period of 10 years. Conservation practices were initiated by communities including the Rupa Lake Restoration and Fishery Cooperative （RLRFC）. As a result, an abundance of non-timber Forest Products （NTFP） has increased considerably. At present, 49 NTFP are available in the lake basin. Some households （HH） i.e 10% has additional income from NTFP. It is an indirect source of food security for local people. They sell NTFP products to generate income. A few households have already started farming of NTFPs. Availability of fodder and fuel wood from community forest has significantly contributed to the livelihoods of people where as wild edible fruits and vegetables have become supplementary for food security. There is yearly food security for 57% of HH with 22% having surplus food. 5% of HH has food security for less than three months where as 19% HHs have food security for more than six months. However, livelihood and nutritional security have improved by fish farming in lake. This lake is most important for the local environment and also helps eco-tourism. The study found that 92% observed the climate change in the form of a rise in temperature （〉 70% HHs）; unpredictable rainfall （〉 75% HHs）; shifting rainfall （〉 60% HHs）; phonological changes （〉 50%）. It showed that the lake supports the restoration of natural water capacity, maintain local climate and sound environment by better natural resource management for an environment friendly ecosystem.
