Display omitted
Cancer is an abnormal condition leading to uncontrolled cell division which causes damage to the body tissues. Around 100 types of cancer are studied so far namely breast cancer, lung ...cancer, skin cancer, prostate cancer, colon cancer and lymphoma. Major cancer therapies include chemotherapy, surgery and radiations but their major drawbacks are non-specifically distributed antitumor agents, uneven delivery of drug concentration to the tumour and low monitoring. Nanoparticles (NPs) are the newly trending field of nanomedicine implied in cancer therapy. The structural characteristics of NPs makes them excellent mode for targeting and penetrating the abnormal cell growth caused by cancer. They can potentially enter the abnormal cells causing DNA damage and determine the defects in the genes. Apart from targeting cancer cells they also aid in drug delivery, imaging of abnormal cells, release and monitoring of therapeutic agents against cancer. The present review deals with the inorganic NPs mediated pharmacotherapy, potential strategies for developing drug delivery system, evaluate the merits and demerits of traditional chemotherapy and nanotherapy for significantly improving the treatment of cancers.
Till date no medication or vaccine is available to cope with the COVID-19 infection and infection rate is increasing drastically across the globe. Only preventive measures and healthy life style with ...efficient immune system have been suggested by WHO to fight and stay safe from COVID-19. WHO recommended alcohol based hand sanitizers for frequent hand hygiene, which are mainly made up from ethanol, isopropyl alcohols, hydrogen peroxides in different combinations. These preparations may become toxic to human health and environment when misused. These chemicals have known toxic and hazardous impact on environment when released by evaporation. In early five months of 2020, American Association of Poison Control Center reported 9504 alcoholic hand sanitizer exposure cases in children under the age of 12 years and recognized that even a small amount of alcohol can cause alcohol poisoning in children that is responsible for confusion, vomiting and drowsiness, and in severe cases, respiratory arrest and death. Furthermore, frequent usage of said hand sanitizers has reported increased chance of antimicrobial resistance and chance of other viral diseases. Current review is designed with main objective to highlight the toxic and serious health risks to human health and environment by frequent using hand hygiene products with alcohols based formulations.
Display omitted
•Alcohol based hand sanitizers are recommended by WHO as preventive measure of COVID-19.•Till April 2020, 7593 hand sanitizer exposure cases of children were reported.•Frequent usage of hand sanitizers results antimicrobial resistance.•Frequent usage of hand sanitizers enhance the chance of other viral diseases.
•Analyzing the recent developments in pyrolysis processes of microalgae.•Mechanism of the various types of pyrolysis was summarized.•Biochemical composition was discussed in detail.•Microwave ...assisted pyrolysis has achieved more significance than other process.•Quality of the bio-oil in catalytic pyrolysis was higher than thermal pyrolysis.
Algae become reasonable feedstock in recent times for biofuel production as they are environmentally benign, sustainable and renewable biomass. Biofuels are produced from algal biomass by chemical, biochemical, and thermochemical methods. Among the thermochemical techniques, pyrolysis is a well-known method involving high temperature and high pressure to produce biochar and bio-oil from numerous algal biomasses. Therefore, this review was undertaken to collate and discuss different pyrolytic processes employed for the conversion of algal biomass into biochar and bio-oil production. At the outset, different pyrolysis methods slow pyrolysis, fast/flash pyrolysis, catalytic pyrolysis, microwave assisted pyrolysis and hydropyrolysis operated for the conversion of various microalgae and cyanobacteria into biochar and bio-oil were reviewed using copious literature. Further, challenges arisen out of using above-said pyrolysis methods were critically highlighted to pave the way to choose an appropriate pyrolysis method for obtaining desirable quantity and quality of bio-oil from algae.
This paper illustrates the method to predict the production of biohydrogen and biogas from the horizontal and vertical continuous mixed tank reactor using a numerical approach. Utilization of ...computational fluid dynamics on the estimation of bioreactor performance is very crucial owing to the uncertainty in the numerical results. Since there has been little work on CFD to determine the influence of hydraulic retention time, impeller speeds, vortex growth, and pH on biohydrogen yield rate the effort had been made. A series of simulations are done with optimal boundary conditions to ensure maximum hydrogen and biogas production rate. Two types of reactors HCSTR and VCSTR are operated at different impeller speed from 40 rpm to 120 rpm. Further, the rate of HRT and organic loading are varied. As the rpm of the impeller increase the rate of hydrogen and biomass production increases not later than 80 rpm. Meanwhile, the optimal range of HRT and pH are 4–8 h and 6.0–8.0. Running the impeller at optimized rate with derived conditions leads to high hydrogen and biogas production of 6 LH2/Ld and 30 L/d. The obtained results are validated with the experimental findings to compare the uncertainty formed due to the numerical simulations. The optimum boundary condition obtained from the study is expected to provide the essential knowledge in establishing the full-scaled reactors.
Display omitted
•Biohydrogen production using HCSTR and VCSTR were performed numerically.•CFD reactor model were developed successfully and validated.•VCSTR impellers effectively increased the bioH2 production.•Hydrodynamic forces enables higher H2 production.•H2 yield affected by impeller speed and HRT.
•Microalgae are considered as the reliable resources of biodiesel production.•Produce third generation biofuel with high productivity value.•Promising impacts of physical pretreatment on microalgal ...biomass.•Review towards physical abiotic factors and pretreatment of microalgae.
The most advantageous renewable energy source which is still being explored for the source of renewable energy is biodiesel. But the major hindrance factor in the part of commercialization is the raw material cost under large scale various. Microalgae derived biofuels have drawn compelling interest as a sustainable and potential fossil fuel. The cellular mechanism of microalgae has been found to alter by the effect of some biotic and abiotic factors. Above all, those environmental parameters and production conditions can also act as a critical factor in altering the component quantity and quality of the biodiesel produced by microalgae. The lipids are accumulated inside the oleaginous microbial cells in the form of lipid droplet, and hence the cell disruption is essential for lipid extraction to enhance the yield. Huge varieties of physicochemical and mechanical pretreatment methods are available to facilitate extraction by effective cell membrane degeneration of oleaginous microbes. The present review is to exploit the probable magnitude and advantages of abiotic factors towards microalgal growth and biodiesel production. Additionally, this study tried to evaluate the possible certainties of the microalgal pretreatment processes in lipid accumulation.
Display omitted
Thermochemical methods namely pyrolysis, gasification/hydrothermal gasification, combustion, hydrothermal liquefaction and hydrothermal carbonization are widely practiced to convert ...algal biomass into fuels. Among the methods, pyrolysis, and hydrothermal liquefaction are most commonly practised to convert numerous algal biomasses into bio-oil and/or biochar to substitute crude oil in petroleum refinery. In this regard, this review is focused on the conversion of various microalgal; and cyanobacterial biomasses into bio-oil, and solid char products through pyrolysis and hydrothermal liquefaction. Initially, pyrolysis and hydrothermal liquefaction of algal biomass on bio-oil and biochar yield have been reviewed. As the composition and yield of bio-oil from algae depends on the reaction temperature, detailed account of the impact of temperature on the quantity and quality of bio-oil and solid char obtained from pyrolysis and hydrothermal liquefaction were comprehensively presented in the review. Eventually, this article provides opportunities and scope in the pyrolysis and hydrothermal liquefaction of algae for further research.
The growing population and increased disposal of end-of-life (EoL) electrical and electronic products have caused serious concerns to the environment and human health. Electronic waste (e-waste) is a ...growing problem because the quantity and the rate at which it is generated has increased exponentially in the last 5 years. The rapid changes or upgradation in technologies, IT requirements for working or learning from home during COVID-19, manufacturers releasing new electronic gadgets and devices that serves the consumers comfort and a declension in services has contributed to an increase in the e-waste or waste of electrical and electronic equipment (WEEE) generation rates. The current status of e-waste generation, handling procedures and regulatory directives in USA, EU, China, India, Vietnam and Gulf Cooperation Council (GCC) countries are presented in this review. The recent developments in e-waste recycling methods/recovery of base and precious metals, the advantages and limitations of hydrometallurgy, pyrometallurgy, biohydrometallurgy and pyrolysis are discussed. Considering the impediments in the present technologies, the extraction of valuable resources, i.e. precious metals, from e-waste using suitable biocatalysts shows promising applications. This review also stresses on the research needs to assess the economic effects of involving different unit operations/process industries for resource recovery, reuse and recycling.
Display omitted
•E-waste generation in developing and developed countries were analyzed.•E-waste treatment options for resource recovery (i.e. precious metals) were reviewed.•Biohydrometallurgy: eco-friendly, less energy requirement and cost effective.•Preventative, recycling and e-waste reduction routes were recommended.
Display omitted
Considering the present energy demand and industrial growth, finding a potential sustainable energy source is crucial. Among renewable fuels, hydrogen is considered to be the primary ...choice as it offers substantial benefits over other conventional fuels. Hydrogen can be generated from waste substrates, is cleaner, and has the highest energy density when compared to conventional fuels. Hydrogen production, particularly biological hydrogen production, is believed to be cost-efficient as it can be successfully performed in ambient conditions with easy operational techniques in an environmental-friendly manner. This review summarizes the different routes of biological hydrogen production including biophotolysis, indirect photolysis, dark fermentation, photofermentation, and microbial electrolysis. Further, leading microorganisms involved in biohydrogen production, such as Clostridium spp., Enterobacter spp., Bacillus spp., Escherichia coli, thermophilic lactic acid bacteria, and Klebsiella spp., along with the molecular approaches employed for the enhancement of biohydrogen production are discussed. In addition, a thorough techno-economic analysis of factors involved in the scale-up of hydrogen production is carried out.
Display omitted
•Challenges faced in I generation biofuels and transition to II generation biofuels.•Microalgae as a feedstock for biofuel production has been discussed in this review.•Two stage ...cultivation strategies and extraction techniques were discussed.•HTL, fermentation, transesterification and pyrolysis of III generation biomass in briefly analyzed.
This critical review summarizes the utilization of algae as the resilient source for biofuel. The paper validates the different stages in generation of biofuels and provides a clarity on III generation biofuels. The microalgae is focused as an incredible source and a detailed discussion has been carried out from the cultivation, extraction and conversion to the final product. An elaborate view on conversion methodologies and troubles involved in the respective techniques are presented. The efficiency of the algal fuel performing in I/C engines derived from major techniques is considered. There exist new challenging barriers in the implementation of microalgae as prospective source in the energy market. In addition, types of pyrolysis for the production of main product from microalgae had been discussed in detail. Besides, some microalgae grow easily from fresh to waste water, make it more feasible source. Although the microalgae are a best alternative, cost of production and the yield of biofuel are still challenging. Further, cultivation of microalgae is very effective by applying two stage cultivation strategies. This comprehensive review provides the useful tool to identify, innovate and operate microalgae as the potential based biofuel.
Display omitted
•First report about biomining potential of A. thiooxidans isolated from bauxite soil.•Biomining conditions (cell 5 × 105, pH 4, 30 °C, and 80 h) for A. thiooxidans optimized.•A. ...thiooxidans yielded 8.7 of sulfur and 4.2 mg mL−1 of iron from pyrite ore.•26 kDa of sulfur dioxygenase (SDO) extracted from A. thiooxidans.•SDO effectively leached the sulfur into sulfite (4. 9 mg in 30 min of biomining).
Minerals are the most important content for many organisms, including humans. Secondary pollution is produced as a result of chemical-based element extraction. Thus, an eco-friendly approach to extracting elements from various ores is an urgent requirement. Hence, the purpose of this study is to evaluate the biomining potential of Acidithiobacillus thiooxidans (pre isolated) and their enzyme involved in the elements solubilization process using the biomining concept. According to the findings, the previously identified A. thiooxidans from bauxite mine tailings have reasonable biomining competence and produced sulfur as a core element and iron as a byproduct from powder for pyrite ore. Under optimal biomining reaction conditions (culture density 5 × 105, pH 4, 30 °C, and 80 h) the A. thiooxidans produced the 8.7 and 4.2 mg mL−1 of sulfur and iron from pyrite ore, respectively. Furthermore, the enzyme responsible for this biomining potential in A. thiooxidans was extracted and identified as sulfur dioxygenase (SDO) with a molecular weight of about 26 kDa using SDS PAGE analysis. Through the oxidation process, the extracted SDO leached the sulfur and produced 4. 9 mg of sulfite after 30 min of biomining. These findings suggested that A. thiooxidans and their intracellular enzyme SDO enzyme could be useful for using in the biomining process on pyrite ore as an environmentally friendly approach.
PDF
