Sort:
Show:
Page Size:
Topic review
Updated time: 11 Oct 2021
Submitted by: Haibo Yuan
Definition: HMF, an indispensable member of the furan-based platform compound, known as the “sleeping giant”, is a bridge between renewable biomass and industrial bulk chemicals. In recent years, the catalytic transformation of biomass to HMF has been widely studied and envisaged to be hopeful in achieving sustainable biorefineries. The synthesis of HMF from biomass requires the acid hydrolysis of biomass to hexose, and then dehydration of hexose, to obtain HMF. In the second step of dehydration, starting from ketohexose (fructose) is more efficient than starting from aldohexose (glucose).
Unfold
Topic review
Updated time: 19 Oct 2021
Definition: Toward improved printed circuit board recycling, recent development and research favours a strategy based on first dismantling WPCBs followed by efficiently sorting electronic components (ECs). This allows obtaining various fractions: (i) bare boards; (ii) solder; (iii) ECs sorted in elementally enriched subfractions. The goal is for each fraction, or subfraction, to have the simplest elemental composition possible, making them easier to reuse directly or recycle, and making it now possible to recover valuable metalssuch as Ti, GaBa, Ta, Nb, W, Lanthanides.
Topic review
Updated time: 08 Oct 2021
Definition: Throughout this review, we have highlighted the current potential of agave by-products as low-cost and natural materials with several applications as biofuels, materials for nanocomposites, and functional ingredients. Among the methods used for by-products processing, US and microwaves are promising and eco-friendly methods for the efficient saccharification and increased digestibility of agave, that can eventually replace chemical processing, reducing waste generation.In this regard, future studies are required concerning accessible, low-cost, and more efficient technologies as a more attractive way for the industry to make a sustainable utilization of this by-product.
Unfold
Topic review
Updated time: 16 Dec 2020
Definition: Alkylimidazoles have good complexing properties, also they are cheap so can be successfully used in the separation of metal ions from aqueous solutions.
Entry Collection : Wastewater Treatment
Unfold
Topic review
Updated time: 26 Oct 2020
Submitted by: Letlhogonolo Selaledi
Definition: The utilization of antibiotics in feed has been reevaluated since bacterial pathogens have established and shared a variety of antibiotic resistance mechanisms that can easily be spread within microbial communities. Multiple countries have introduced bans or severe restrictions on the non-therapeutic use of antibiotics. Since the use of antibiotics may have a positive influence on poultry performance, excessive use as growth promoters harms human health. This has therefore warranted the urgent need for alternatives.
Entry Collection : Wastewater Treatment
Unfold
Topic review
Updated time: 19 Oct 2020
Submitted by: Yongmei Jia
Definition: Aflatoxin B1 (AFB1) is one of the most frequently-found mycotoxins in contaminated food. As the content of mycotoxins is particularly low in food, the development of probes to detect AFB1 in foods with high sensitivity and selectivity is an urgent social need for the evaluation of food quality. Numerous techniques have been developed to monitor AFB1. Nevertheless, most of them require cumbersome, labor-consuming, and sophisticated instruments, which have limited their application. An aptamer is a single, short nucleic acid sequence that is capable of recognizing different targets. Owing to their unique properties, aptamers have been considered as alternatives to antibodies. Aptasensors are considered to be an emerging strategy for the quantification of aflatoxin B1 with high selectivity and sensitivity.
Unfold
Topic review
Updated time: 24 May 2021
Submitted by: Osama Al-Madanat
Definition: In recent years, the intensification of human activities including rapid urbanization, industrialization, population, and economic growth, led to an increase in waste production and energy demand. Most importantly such activities pose concerns for health, energy security and climate changes. Hazardous volatile organic compounds, VOC, and aromatic organic compounds, AOC, are being generated from the activities of many vital industries like mining and petrochemicals. They are instrumental in the economic growth of many countries and their products are regarded as privileges to modern communities. Nevertheless, they are toxic and carcinogenic thus, these wastes have been classified as “hazardous”. The simultaneous treatment of organic pollutants and energy recovery is an attractive solution to reduce pollution in water, air, and soil as well as provide alternative clean energy sources. Hydrogen could be generated from organic pollutants in water through photocatalysis. Photocatalysis refers to the oxidation and reduction, redox, reactions on semiconductor surfaces, mediated by the valence band holes and conduction band electrons, which are generated by the absorption of ultraviolet or visible light radiation. Compared to traditional oxidation processes, photocatalytic redox reaction operates at ambient conditions without a high temperature or high pressure, and many recalcitrant organic contaminants can be degraded without the addition of chemical oxidants, hence it is fully green process. Among the various photocatalysts, TiO2, as the most widely employed “golden” photocatalyst, has been largely used in photocatalysis, due to its chemical stability, nontoxicity, and low cost. In the last two decades, TiO2 photocatalysis has expanded very quickly, having undergone various development‐related energy issues and environmental issues, such as direct solar H2O splitting into H2 and the decomposition of pollutants in air and H2O at low concentrations. Although great progress has been made in TiO2 photocatalysis, much remains unknown, which raises an interesting challenge not only for engineers but also for basic scientists. a typical photocatalytic reaction in TiO2 photocatalysis contains many fundamental processes, including charge carrier formation, separation, relaxation, trapping, transfer, recombination, and transportation.
Unfold
Topic review
Updated time: 19 Jul 2021
Submitted by: Katja Vasić
Definition: Lignocellulosic sources are the world’s largest renewable sources for bioethanol production and can be divided into three main types: (1) marine algae, (2) agricultural residues and municipal solid wastes, (3) and forest woody feedstocks.
Entry Collection : Environmental Sciences
Unfold
Topic review
Updated time: 21 Aug 2021
Submitted by: Abdelrahman Zaky
Definition: Bioethanol has many environmental and practical benefits as a transportation fuel. It is one of the best alternatives to replace fossil fuels due to its liquid nature, which is similar to the gasoline and diesel fuels traditionally used in transportation. In addition, bioethanol production technology has the capacity for negative carbon emissions, which is vital for solving the current global warming dilemma. However, conventional bioethanol production takes place based on an inland site and relies on freshwater and edible crops (or land suitable for edible crop production) for production, which has led to the food vs. fuel debate. Establishing a coastal marine biorefinery (CMB) system for bioethanol production that is based on coastal sites and relies on marine resources (seawater, marine biomass and marine yeast) could be the ultimate solution. In this paper, we aim to evaluate the environmental impact of using seawater for bioethanol production at coastal locations as a step toward the evaluation of a CMB system. Hence, a life cycle assessment for bioethanol production was conducted using the proposed scenario, named Coastal Seawater, and compared to the conventional scenario, named Inland Freshwater (IF). The impact of each scenario in relation to climate change, water depletion, land use and fossil depletion was studied for comparison. The Coastal Seawater scenario demonstrated an improvement upon the conventional scenario in all the selected impact categories. In particular, the use of seawater in the process had a significant effect on water depletion, showing an impact reduction of 31.2%. Furthermore, reductions were demonstrated in natural land transformation, climate change and fossil depletion of 5.5%, 3.5% and 4.2%, respectively. This indicates the positive impact of using seawater and coastal locations for bioethanol production and encourages research to investigate the CMB system.
Entry Collection : Environmental Sciences
Unfold
Topic review
Updated time: 28 Oct 2020
Submitted by: Lon Brouse
Definition: Industrial comfort cooling and process cooling typically employ water evaporative cooling towers (CTs) to dissipate reject heat. This warm water, enriched with nutrient materials scrubbed from the air or in source water, provides a nurturing environment for a wide variety of neutrophilic microorganisms, some of which are human pathogens. For example, cases of Legionella pneumophila infection have been traced to CT Systems that have become pubic hazards in recent years. Typically, one or more toxic microbicides are applied to control the problem. This article highlights two case studies that utilize ultra-softened (<0.3 mg/L total hardness), highly-concentrated chemical components, naturally present in almost all makeup water sources used by CT Systems, that can generate high-pH, high-TDS cooling water. At sufficient concentrations, these two natural parameters are hostile to microorganisms, including protozoa and slime-forming (biofilm) bacteria that harbor pathogens. Field testing for Adenosine Tri-Phosphate (ATP), reported in Relative Light Units (RLU), provides a quick, sensitive method to detect all water-borne microbiological activity present in CT Systems and verifies the effectiveness of the anti-microbial program by quantifiable data, reported as ATP-RLU.
Unfold
  • Page
  • of
  • 10