Membrane reactors for bioethanol production and processing

Dwindling supplies of fossil fuel along with detrimental release of greenhouse gases have led to the quest for renewable sources of fuel such as bioethanol from cellulosic materials. Conversion of biomass to bioethanol involves a set of “biotransformation” and “recovery/concentration” processes. With the help of membrane technology, several process steps that were conventionally separate can be integrated and the production of bioethanol simplified. In addition to efficient recovery of bioethanol, this can facilitate removal of inhibitory side products from the fermentation broth and recovery of the inhibitory but valuable side products. This chapter provides a critical review of the application of membrane technology in various steps of bioethanol production. The challenges to widespread deployment of full-scale bioethanol facilities equipped with membranes have also been outlined

Pesticide removal by a mixed culture of bacteria and white-rot fungi

Combining activated sludge cultures with microbes harboring specific degradation pathways could constitute a relevant process for the removal of toxic and recalcitrant organic substances from wastewater. Enhanced removal of three widely used recalcitrant pesticides from their liquid mixture was demonstrated by implementing a non-acclimated mixed culture of bacteria and white-rot fungus. During an incubation period of 14 days, the mixed fungus-bacteria culture achieved 47, 98, and 62% removal of aldicarb, atrazine and alachlor from the liquid phase, respectively. This compared favorably to batches containing only non-acclimated fungus or previously published removal rates with non-acclimated bacterial cultures. Biosorption along with biodegradation was responsible for the removal of the pesticides from the liquid phase. Potential application modes of the studied biodegradation process were also discussed

Pesticide removal by a mixed culture of bacteria and white-rot fungi

Combining activated sludge cultures with microbes harboring specific degradation pathways could constitute a relevant process for the removal of toxic and recalcitrant organic substances from wastewater. Enhanced removal of three widely used recalcitrant pesticides from their liquid mixture was demonstrated by implementing a non-acclimated mixed culture of bacteria and white-rot fungus. During an incubation period of 14 days, the mixed fungus-bacteria culture achieved 47, 98, and 62% removal of aldicarb, atrazine and alachlor from the liquid phase, respectively. This compared favorably to batches containing only non-acclimated fungus or previously published removal rates with non-acclimated bacterial cultures. Biosorption along with biodegradation was responsible for the removal of the pesticides from the liquid phase. Potential application modes of the studied biodegradation process were also discussed

Dimethoate residues in Pakistan and mitigation strategies through microbial degradation: a review

Organophosphate pesticides (OPs) are used extensively for crop protection worldwide due to their high water solubility and relatively low persistence in the environment compared to other pesticides, such as organochlorines. Dimethoate is a broad-spectrum insecticide that belongs to the thio-organophosphate group of OPs. It is applied to cash crops, animal farms, and houses. It has been used in Pakistan since the 1960s, either alone or in a mixture with other OPs or pyrethroids. However, the uncontrolled use of this pesticide has resulted in residual accumulation in water, soil, and tissues of plants via the food chain, causing toxic effects. This review article has compiled and analyzed data reported in the literature between 1998 and 2021 regarding dimethoate residues and their microbial bioremediation. Different microorganisms such as bacteria, fungi, and algae have shown potential for bioremediation. However, an extensive role of bacteria has been observed compared to other microorganisms. Twenty bacterial, three fungal, and one algal genus with potential for the remediation of dimethoate have been assessed. Active bacterial biodegraders belong to four classes (i) alpha-proteobacteria, (ii) gamma-proteobacteria, (iii) beta-proteobacteria, and (iv) actinobacteria and flavobacteria. Microorganisms, especially bacterial species, are a sustainable technology for dimethoate bioremediation from environmental samples. Yet, new microbial species or consortia should be explored