RESUMO
Volatile fatty acids (VFAs) are the building blocks of the chemical industry, and they are the primary contributors to the planet's organic carbon cycle. VFA production from fossil fuels (mostly petroleum) is unsustainable, pollutes the environment, and generates greenhouse gases. As a result of these issues, there is a pressing need to develop alternate sources for the long-term generation of VFAs via anaerobic digestion. The accessible feedstocks for its sustainable production, as well as the influencing parameters, are discussed in this review. The use of VFAs as a raw material to make a variety of consumer products is reviewed in order to find a solution. It also bridges the gap between traditional and advanced VFA production and utilization methods from a variety of solid and liquid waste sources for economical stability.
Assuntos
Ácidos Graxos Voláteis , Gases de Efeito Estufa , Anaerobiose , Reatores Biológicos , Fermentação , Concentração de Íons de HidrogênioRESUMO
Batch leaching experiments were conducted to estimate the leaching of As(III) and As(V) from exhausted CalSiCo. The leaching of As(III) and As(V) was found to be function of time and concentrations of anions such as Cl-, NO3-, SO4(2-) in extraction fluid. Extraction tests were carried out to determine the maximum leachable concentration under the chosen conditions of leaching medium and leaching time. It has been observed that the leaching of As(III) is more than As(v) in all the cases. Leaching of As(III) and As(v) from exhausted CalSiCo is also carried out in rainwater and in tap water. It is observed that leaching of As is more in rainwater than tap water. Further higher leaching is observed in case of fluids containing chloride compared to those containing nitrate and sulphate.