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Algae biomass has been recognized as one of the most suitable, efficient, and reliable feedstocks for bio-oil production. Among the different processes, hydrothermal liquefaction (HTL) is emerging as an effective technology for the valorization of various types of wet or dry biomass. Several factors, including temperature, retention time, and catalyst, significantly influence the overall efficiency of HTL products. The temperature ∼280 ± 40 °C is reported to be the most suitable range to achieve maximum bio-oil. Both homogeneous and heterogeneous catalysts have been used to improve bio-oil yield. For several advantages, heterogeneous catalysts are the preferred choice due to improved bio-oil generation, easy recovery, and uses. The eco-friendly approach and the reduction of heteroatoms in bio-oils make heterogeneous catalysts an ideal choice to be fortified. Alkaline catalysts have been considered most suitable to improve HTL yield. Variations in temperature and catalysts not only influence the yield of the bio-oil but also influence the characteristics of the bio-oil (e.g. high heating value, oxidative stability, gaseous emission, etc.) simultaneously. This review reveals interesting features including HTL temperature vs. yield, catalysts vs. yield, and the effect of wet and dry biomass on bio-oil properties, and finally, observations, remarks/limitations are presented for future studies.

The fabrication of the inorganic metal oxide nanoparticles by using extract of the different part of the plant was gaining an overwhelming response from the last few years. Magnetic iron oxide nano...

The development of nontoxic bio-waste based catalyst for efficient recycling of textile dye wastewater to potable water is paramount to support a sustainable environment. This research work investi...

Utilization of harmful algal blooms (HABs) for the cultivation of oleaginous microorganisms can provide dual benefits of mitigating the toxicity from the aquatic reservoirs and generation of copious media for biodiesel production. In the present investigation, microwave-assisted dilute alkali-freeze pretreatment was optimized to develop a low-cost growth medium from HAB dried biomass. The electron micrographs along with the elemental analysis confirmed the efficient breakage of HABs after the microwave-assisted hydrolysis treatment as compared with the acid hydrolysis. Moreover, the sugar analysis revealed ~ 46% higher carbohydrate content in microwave-assisted hydrolysate as compared with acid hydrolysate. The microwave-assisted hydrolysate and conventional dilute acid hydrolysate were then used to cultivate microalga (Chlorella minutissima) and yeast (Trichosporon cutaneum) for biomass and lipid accumulation and compared to artificial media. Microalga showed ~ 1.3- and 2-fold higher dry cell weight (DCW) and lipid content, respectively, while the yeast growth increased by ~ 27% with lipid content of 30%. The fatty acid profiles and biodiesel properties were also amenable to the international biodiesel standards. Hence, the present study provides a proof-of-concept of utilizing HAB hydrolysate for culturing oleaginous microorganisms for potential biodiesel production.

The present paper reports the green synthesis of TiO2 NPs to evaluate its photocatalytic activity. In this synthesis we use Aegle marmelos leaf extract as reducing and stabilizing agent. The TiO2 nanoparticles were characterized by using various advance analytical tools. The FTIR analysis revels the presence of different functional group present on the surface of the fabricated nanoparticles. The result of SEM analysis indicated that the prepared nanoparticles were almost spherical in nature and particles are in agglomerated state with bunch size less than 150 nm. The X-ray analysis of our synthesized nanoparticles clearly indicated that the particles are exit in anatase phase. Photocatalytic degradation studies of our nanoparticles were also evaluated against the most common nitroimidazole derivative drug ornidazole (ODZ) and the result of this study provide a good alternative path to remove the ODZ contaminants from waste water. The photocatalytic degradation of selected drug follow pseudo-first order reaction.

The novelty of this present work is to investigate the anti-bacterial and anti-fungal activity of the green synthesized titanium dioxide (TiO2) nanoparticles using leaf extract of Mentha arvensis, ...

We report a facile method for rapid synthesis of highly crystalline superparamagnetic Fe3O4 nanoparticles with crystallite size in the range of 25–33 nm via microwave synthesizer. The Fe3O4 stabilized with PVP was used to synthesize strong magnetized spherical polymeric magnetic composites (PMCs) in the range 0.3–1.5 µm via microwave irradiated emulsion polymerization using vinyl monomers. The influence of reaction time and the amount of reactive reagents on the structure, morphology, thermal stability and magnetic property of synthesized PMCs were examined. HR-TEM revealed the incorporation of superparamagnetic Fe3O4 nanoparticles in the cross-linked polymeric matrix of poly(styrene-divinylbenzene-acrylic acid). The synthesized Fe3O4 nanoparticles exhibit superparamagnetic behavior at 300 K with a high saturation magnetization 67.5 emu/g for MNP-3. Interestingly, the as-synthesized magnetically responsive PMCs [Fe3O4/P(St-DVB-AA)] exhibit ferromagnetic properties with enhanced saturation magnetization in the measured temperature interval of 10–350 K, which is in contrast with the superparamagnetic behavior of synthesized Fe3O4 nanoparticles. An excellent saturation magnetization 22.5 emu/g was noted for the composite PMC-10 loaded with ∼24% magnetic nanoparticles. Further, the as-synthesized Fe3O4 nanoparticles and polymer magnetic composites exhibit the charge ordering (Verwey transition) at low temperature in the range 30–41 K and 23–25 K, respectively.

Green oleaginous microalgae are good candidates for the integration of heavy metal bioremediation with the generation of biofuels. To be effective, this requires a comprehensive understanding and optimization of the metal concentration that generates maximum growth along with a high yield of lipids from microalgae cells. This work follows the aforementioned strategy and involves the use of oleaginous microalgae Chlorella sorokiniana for lead mitigation and biodiesel production. The short-term effects (IC50 value at 96 h of culture) and the long-term effects (pigments and biomass) of the exposure of lead (Pb) to the growth and biochemical compositions (pigments, proteins, carbohydrates, and lipids) of microalgae have been also determined. Chlorella sorokiniana has a high half-maximal inhibitory concentration (IC50 value and higher metal bio-concentration factor (BCF) for Pb (II), which represents that this strain can be considered as a lead (Pb) hyperbioaccumulator. FTIR analysis revealed a reduction in proteins and carbohydrates under the influence of Pb while an increase in lipids has been recorded. The lipid profile based on 1H NMR and GC–MS has been followed for the quality analysis of the biodiesel produced that indicated altered lipid profiles under stress by Pb and elevated levels of SFA and MUFA.

In this study, hydropyrolysis was carried out using sodium carbonate to convert the green algal bloom into bio-oil, biochar, aqueous solution, and gases. The effect of supercritical conditions (400, 450, 500 °C) on the product yield, bio-oil composition, and structure, and functionalities of the biochar was determined. The high yield of biochar and bio-oil was reported at 400 °C. A significant reduction in bio-oil and increment in hydrocarbon content was reported on the elevation of temperature from 450 °C to 500 °C. After that, kinetic and isotherm analysis was investigated simultaneously to remove four heavy metals viz. Cu(II), Ni(II), Co(II), and Cd(II) from the mixture solution. Results show that kinetics data follow a pseudo-second-order kinetics model and adsorption isotherm is in better agreement with the Langmuir model, not with the Freundlich model. The maximum adsorption capacity was found 10.90, 5.74, 5.80, and 16.28 mg/g with the biochar prepared at 500 °C for Cu(II), Ni(II), Co(II), and Cd(II) metals, respectively. The current investigation provided a promising way for the utilization of freshwater algal bloom biomass for renewable products and simultaneously heavy metal removal from the water.

Few studies are reported on immunomodulatory potential of non-mulberry (Antheraea mylitta) silk fibroin (SF) combined with polyurethane (PU) in diabetic wound healing. In this study, PU/SF (Antheraea mylitta) scaffolds were fabricated by blending and immobilization techniques. Effective SF dosage was determined and incorporated according to minimum inhibitory concentrations against wound associated bacterial strains while fabricating scaffold. Dermal fibroblast NIH3T3 cells were seeded on epidermal growth factor (EGF) treated and untreated PU/SF scaffolds, fabricated by blending and immobilization techniques. Fibroblast seeded PU/SF scaffolds were investigated for anti-inflammatory response in wound recovering potential comparing with Acticoat™ in third degree burn of streptozotocin induced diabetic rats. At 16th, 24th days, promising healing was achieved with faster granulation, enhanced collagenization, patterned re-epithelialization by EGF treated cellular immobilized PU/SF in normal, hyperglycemic burn. Biomarkers of different healing stages, CD31 (haemostasis), Ki67 (proliferative), alpha-sma, COL III (maturation) were examined. Since hyperglycemic burn is characterized by inflated pro-inflammatory cytokines, serum, tissue IL-6,8,10 were recorded, which revealed timely restoration of inflated IL-6,8 and protection against IL-10 elevation by cellular immobilized PU/SF compared to Acticoat™ (p ≤ 0.05), control (p ≤ 0.01). E-cadherin (gap junction protein), MMP 9 response suggested anti-inflammatory role of PU/SF on accelerated healing of thermal injury as potent dermal substitute.

Sericulture is a technique of rearing silkworms on mulberry or non-mulberry plants for the production of silk fibers. It is mainly used for textile industries, but a large amount of sericulture by-products (from silkworm cultivation to post-cocoon technology), can also add the value to the seri-economy. This review presents the diverse promising applications of sericulture natural products and by-products that have an important role in human welfare. It explores multidimensional applications in the fields of regenerative drugs, tissue engineering, medical textiles, drug delivery systems, cosmeceuticals, food additives, and manufacturing of valuable biomaterials. The silkworm pupa conferred the potential applicability in the field of therapeutics, nutritionals, cosmetics, animal feed, fertilizer, etc. Another emerging area have enticed in sustainable applications for biofuels generation by using sericulture wastes. Thus, the traditional sericulture activities have shown its potential for the diverse and novel emerging field of commercial importance including the concept of biorefinery.

Electricity generation from wastewater using a microalgae-based microbial fuel cell (MFC) has captured a lot of attention from researchers these days. Microalgae-microbial fuel cell (m-MFC) is a device that can overcome the problem of fossil-fuel depletion and environmental pollution by generating electrical energy from wastewater and sunlight. Sustainable applications of the microalgae-based microbial fuel cells are not only reliable for wastewater treatment and bio-electricity generation but also versatile in the field of bio-hydrogen energy production, eco-friendly solution of desalination, and carbon sequestration. In this review article, we have summarized the mechanism and operational configuration of the microbial fuel cell using an anode chamber, a cathode chamber, and a separation membrane. The technological advancement of photosynthetic microalgae in the microbial fuel cell for energy production and wastewater treatment has been explored. The use of microalgae species such as the anode and cathode is also conferred with the resulting power densities. The challenges and possible solutions of the microalgae-microbial fuel cells in integrated energy production systems with wastewater treatment have been discussed for potential industrialization.

The influence of glyphosate herbicide stress was investigated in the freshwater green microalgae Chlorella sorokiniana for metabolic growth and lipid induction. Glyphosate herbicide concentration at 30.10 ppm (IC50) elicited half-maximal inhibition during 96 h of incubation. After 24 days of harvest, C. sorokiniana produced 442.18 ± 9.1 mg/L and 427.73 ± 5.0 mg/L dcw of biomass in the control media and glyphosate IC50, respectively. A nominal reduction in biomass production was observed (~ 3.26%) due to stress in metabolic biosynthesis in glyphosate IC50 media. However, in contrast to biomass production, glyphosate IC50 stress aided in the induction of lipid biosynthesis in microalgae cells. The improvement in lipid synthesis was found to be ~17% higher in glyphosate IC50 compared to control. The chemical construction of the biomass, metabolites, and lipids of C. sorokiniana was analyzed via FTIR spectroscopy. The lipids extracted from C. sorokiniana were used for methanolic-H2SO4 catalyzed transesterification for the production of biodiesel. The synthesized biodiesel was analyzed by FTIR and 1H NMR. The conversion efficiency of microalgae lipids into biodiesel was estimated at ~77%. This study insights the use of glyphosate in lipid induction in microalgae to produce renewable and sustainable biofuels for the clean environment.