• Energy Research

Climate-change-induced freshwater shortage and saline intrusion have been posing significant risks to agricultural sectors in arid and semi-arid regions, negatively impacting irrigation, crop yield, and food production. Climate-smart sustainable solutions are the requirement to combat these major concerns. To overcome freshwater scarcity, pressure-driven desalination techniques are used that require advanced operational systems and electricity, which creates an additional economic burden when applied in the agriculture sector. Therefore, more sustainable methods for soil and water desalination using plant-, microbial-, algal-, biomass-, and carbon-based systems are needed. This scoping review addresses the effects of climate change on freshwater shortage and global food production, the influence of salinity and sodicity on agriculture, and sustainable desalination technologies.

Climate-change-induced freshwater shortage and saline intrusion have been posing significant risks to agricultural sectors in arid and semi-arid regions, negatively impacting irrigation, crop yield, and food production. Climate-smart sustainable solutions are the requirement to combat these major concerns. To overcome freshwater scarcity, pressure-driven desalination techniques are used that require advanced operational systems and electricity, which creates an additional economic burden when applied in the agriculture sector. Therefore, more sustainable methods for soil and water desalination using plant-, microbial-, algal-, biomass-, and carbon-based systems are needed. This scoping review addresses the effects of climate change on freshwater shortage and global food production, the influence of salinity and sodicity on agriculture, and sustainable desalination technologies.

Worldwide demand for antibiotics and pharmaceutical products is continuously increasing for the control of disease and improvement of human health. Poor management and partial metabolism of these compounds result in the pollution of aquatic systems, leading to hazardous effects on flora, fauna, and ecosystems. In the past decade, the importance of microalgae in micropollutant removal has been widely reported. Microalgal systems are advantageous as their cultivation does not require additional nutrients: they can recover resources from wastewater and degrade antibiotics and pharmaceutical pollutants simultaneously. Bioadsorption, degradation, and accumulation are the main mechanisms involved in pollutant removal by microalgae. Integration of microalgae-mediated pollutant removal with other technologies, such as biodiesel, biochemical, and bioelectricity production, can make this technology more economical and efficient. This article summarizes the current scenario of antibiotic and pharmaceutical removal from wastewater using microalgae-mediated technologies.

Worldwide demand for antibiotics and pharmaceutical products is continuously increasing for the control of disease and improvement of human health. Poor management and partial metabolism of these compounds result in the pollution of aquatic systems, leading to hazardous effects on flora, fauna, and ecosystems. In the past decade, the importance of microalgae in micropollutant removal has been widely reported. Microalgal systems are advantageous as their cultivation does not require additional nutrients: they can recover resources from wastewater and degrade antibiotics and pharmaceutical pollutants simultaneously. Bioadsorption, degradation, and accumulation are the main mechanisms involved in pollutant removal by microalgae. Integration of microalgae-mediated pollutant removal with other technologies, such as biodiesel, biochemical, and bioelectricity production, can make this technology more economical and efficient. This article summarizes the current scenario of antibiotic and pharmaceutical removal from wastewater using microalgae-mediated technologies.

Rhodococcus sp. YHY01 was studied to utilize various lignin derived aromatic compounds. It was able to utilize p-coumaric acid, cresol, and 2,6 dimethoxyphenol and resulted in biomass production i.e. 0.38 g dcw/L, 0.25 g dcw/L and 0.1 g dcw/L, and lipid accumulation i.e. 49%, 40%, 30%, respectively. The half maximal inhibitory concentration (IC50) value for p-coumaric acid (13.4 mM), cresol (7.9 mM), and 2,6 dimethoxyphenol (3.4 mM) was analyzed. Dimethyl sulfoxide (DMSO) solubilized barley straw lignin fraction was used as a carbon source for Rhodococcus sp. YHY01 and resulted in 0.130 g dcw/L with 39% w/w lipid accumulation. Major fatty acids were palmitic acid (C16:0) 51.87%, palmitoleic acid (C16:l) 14.90%, and oleic acid (C18:1) 13.76%, respectively. Properties of biodiesel produced from barley straw lignin were as iodine value (IV) 27.25, cetane number (CN) 65.57, cold filter plugging point (CFPP) 14.36, viscosity (υ) 3.81, and density (ρ) 0.86.

Rhodococcus sp. YHY01 was studied to utilize various lignin derived aromatic compounds. It was able to utilize p-coumaric acid, cresol, and 2,6 dimethoxyphenol and resulted in biomass production i.e. 0.38 g dcw/L, 0.25 g dcw/L and 0.1 g dcw/L, and lipid accumulation i.e. 49%, 40%, 30%, respectively. The half maximal inhibitory concentration (IC50) value for p-coumaric acid (13.4 mM), cresol (7.9 mM), and 2,6 dimethoxyphenol (3.4 mM) was analyzed. Dimethyl sulfoxide (DMSO) solubilized barley straw lignin fraction was used as a carbon source for Rhodococcus sp. YHY01 and resulted in 0.130 g dcw/L with 39% w/w lipid accumulation. Major fatty acids were palmitic acid (C16:0) 51.87%, palmitoleic acid (C16:l) 14.90%, and oleic acid (C18:1) 13.76%, respectively. Properties of biodiesel produced from barley straw lignin were as iodine value (IV) 27.25, cetane number (CN) 65.57, cold filter plugging point (CFPP) 14.36, viscosity (υ) 3.81, and density (ρ) 0.86.

Abstract Food waste-derived volatile fatty acids (VFAs) can act as a renewable feedstock for biodiesel production. In synthetic media, Rhodococcus sp. YHY01 was able to utilize various organic acids (acetate, butyrate, lactate, and propionate) as a carbon source. Butyrate was the optimal carbon source, having a minimum inhibitory effect on growth, and a maximum growth yield coefficient (Yx/s 0.288 g dcw/g butyrate) and fatty acid yield coefficient (Yf/s 0.206 g/g butyrate), compared to other organic acids (lactate, propionate, and acetate). Acetate, butyrate, and lactate mostly supported the production of fatty acids with an even number of carbons, whereas propionate enhanced the content of odd-numbered fatty acids. Response surface methodology (RSM) design study resulted in maximum biomass (2.8 g/L) and fatty acid yield (1.9 g/g) with acetate:butyrate:lactate (0.333:0.333:0.333) as a carbon source. Culture of Rhodococcus sp. YHY01 in media containing food waste-derived VFAs as the carbon source had a biomass (3.2 g dcw/L), fatty acid yield (2.2 g/L), and fatty acid accumulation (69% w/w) under nitrogen-limited condition. Biodiesel produced from food waste had an iodine value (IV, 37), cetane number (CN, 63), high heating value (HHV, 39), density (υ, 3.9), and viscosity (ρ, 0.868) that meet international standards.

Abstract Food waste-derived volatile fatty acids (VFAs) can act as a renewable feedstock for biodiesel production. In synthetic media, Rhodococcus sp. YHY01 was able to utilize various organic acids (acetate, butyrate, lactate, and propionate) as a carbon source. Butyrate was the optimal carbon source, having a minimum inhibitory effect on growth, and a maximum growth yield coefficient (Yx/s 0.288 g dcw/g butyrate) and fatty acid yield coefficient (Yf/s 0.206 g/g butyrate), compared to other organic acids (lactate, propionate, and acetate). Acetate, butyrate, and lactate mostly supported the production of fatty acids with an even number of carbons, whereas propionate enhanced the content of odd-numbered fatty acids. Response surface methodology (RSM) design study resulted in maximum biomass (2.8 g/L) and fatty acid yield (1.9 g/g) with acetate:butyrate:lactate (0.333:0.333:0.333) as a carbon source. Culture of Rhodococcus sp. YHY01 in media containing food waste-derived VFAs as the carbon source had a biomass (3.2 g dcw/L), fatty acid yield (2.2 g/L), and fatty acid accumulation (69% w/w) under nitrogen-limited condition. Biodiesel produced from food waste had an iodine value (IV, 37), cetane number (CN, 63), high heating value (HHV, 39), density (υ, 3.9), and viscosity (ρ, 0.868) that meet international standards.