-
Waste Management & Research : the... May 2022There is a growing need to recover raw materials from waste due to increasing environmental concerns and the widely adopted transition to circular economy. For waste... (Review)
Review
There is a growing need to recover raw materials from waste due to increasing environmental concerns and the widely adopted transition to circular economy. For waste tyres, it is necessary to continuously develop methods and processes that can devulcanize rubber vulcanizates into rubber products with qualities and properties that can closely match those of the virgin rubber. Currently, the most common, due to its efficiency and perceived eco-friendliness in recovering raw rubber from waste rubbers, such as tyres, is devulcanization in supercritical carbon dioxide (scCO) using commercial and typical devulcanizing agents. The scCO has been generally accepted as an attractive alternative to the traditional liquid-based devulcanization media because of the resultant devulcanized rubber has relatively better quality than other processes. For instance, when scCO is employed to recover rubber from waste tyres (e.g. truck tyres) and the recovered rubber is blended with virgin natural rubber (NR) in various compositions, the curing and mechanical properties of the blends closely match those of virgin NR. The atmospheric toxicity and cost of the commonly used devulcanization materials like chemical agents, oils and solvents have enabled a shift towards utilization of greener (mainly organic) and readily available devulcanization chemical components. This literature review paper discusses the approaches, which have less negative impact on the environment, in chemical devulcanization of rubber vulcanizates. A special focus has been on thermo-chemical devulcanization of waste tyres in scCO using common organic devulcanizing agents.
Topics: Carbon Dioxide; Motor Vehicles; Organic Chemicals; Rubber
PubMed: 33829913
DOI: 10.1177/0734242X211008515 -
Critical Reviews in Analytical Chemistry 2020Aquatic passive samplers have been extensively tested and deployed in the field over the past two decades. Among these devices is relatively recently developed the Polar... (Review)
Review
Aquatic passive samplers have been extensively tested and deployed in the field over the past two decades. Among these devices is relatively recently developed the Polar Organic Chemical Integrative Sampler (POCIS) for isolation of hydrophilic organic micropollutants in aquatic environment. The use of POCIS allows the measurement of low and fluctuating trace concentrations of such micropollutants, which is often troublesome using classical sampling. In this review, POCIS applications based on numerous articles to assess the suitability of these devices for use in environmental analytics information were summarized. Additionally, the possibilities of using POCIS for the isolation of complex chemical mixtures in order to highlight the high potential of this devices were presented. The types of sorbents used in POCIS, exposure duration and sampling media are juxtapose in this review. Based on the existing literature, attention was paid to both promising opportunities but also to limitations of passive methods.
Topics: Biosensing Techniques; Environmental Monitoring; Fluorocarbons; Organic Chemicals; Water Pollutants, Chemical
PubMed: 31204504
DOI: 10.1080/10408347.2019.1565983 -
Brazilian Journal of Biology = Revista... 2023Nanosensors work on the "Nano" scale. "Nano" is a unit of measurement around 10- 9 m. A nanosensor is a device capable of carrying data and information about the...
Nanosensors work on the "Nano" scale. "Nano" is a unit of measurement around 10- 9 m. A nanosensor is a device capable of carrying data and information about the behavior and characteristics of particles at the nanoscale level to the macroscopic level. Nanosensors can be used to detect chemical or mechanical information such as the presence of chemical species and nanoparticles or monitor physical parameters such as temperature on the nanoscale. Nanosensors are emerging as promising tools for applications in agriculture. They offer an enormous upgrade in selectivity, speed, and sensitivity compared to traditional chemical and biological methods. Nanosensors can be used for the determination of microbe and contaminants. With the advancement of science in the world and the advent of electronic equipment and the great changes that have taken place in recent decades, the need to build more accurate, smaller and more capable sensors was felt. Today, high-sensitivity sensors are used that are sensitive to small amounts of gas, heat, or radiation. Increasing the sensitivity, efficiency and accuracy of these sensors requires the discovery of new materials and tools. Nano sensors are nanometer-sized sensors that, due to their small size and nanometer size, have such high accuracy and responsiveness that they react even to the presence of several atoms of a gas. Nano sensors are inherently smaller and more sensitive than other sensors.
Topics: Organic Chemicals; Nanoparticles; Agriculture
PubMed: 37194801
DOI: 10.1590/1519-6984.268893 -
Environmental Pollution (Barking, Essex... Nov 2021Despite the importance of bioavailability for organic chemical bioaccumulation by terrestrial and benthic invertebrates, the principles of bioavailability for organic...
Despite the importance of bioavailability for organic chemical bioaccumulation by terrestrial and benthic invertebrates, the principles of bioavailability for organic chemical bioaccumulation remain poorly understood. Here we use large-scale databases with contrasting geographic, compound and organism coverage (from 925 sites, 446 compounds and 184 invertebrate species), and report that bioavailability for organic chemical bioaccumulation follows the power law. It represents that the internal concentration of organic chemicals is the composite power function of the lipid fraction of invertebrates, bulk site concentration of compounds, and organic carbon content of soils/sediments. This law directly links environmental exposures and body burdens of organic chemicals in contaminated sites, and provides a method for enabling case-specific risk assessments of a vast number of organic chemicals and contaminated sites. Our findings may pave the way for translating bioavailability knowledge into risk-oriented regulation of organic chemicals and contaminated sites.
Topics: Animals; Bioaccumulation; Biological Availability; Geologic Sediments; Invertebrates; Organic Chemicals; Water Pollutants, Chemical
PubMed: 34247003
DOI: 10.1016/j.envpol.2021.117716 -
Journal of Contaminant Hydrology Jun 2022The provision of clean water is still a major challenge in developing parts of the world, as emphasized by the United Nation Sustainable Development Goals (SDG 6), and... (Review)
Review
The provision of clean water is still a major challenge in developing parts of the world, as emphasized by the United Nation Sustainable Development Goals (SDG 6), and has remained a subject of extensive research globally. Advancements in science and industry have resulted in a massive surge in the amount of industrial chemicals produced within the last few decades. Persistent and emerging organic pollutants are detected in aquatic environments, and conventional wastewater treatment plants have ineffectively handled these trace, bioaccumulative and toxic compounds. Therefore, we have conducted an extensive bibliometric analysis of different materials utilized to combat organic pollutants via adsorption and photocatalysis. The classes of pollutants, material synthesis, mechanisms of interaction, merits, and challenges were comprehensively discussed. The paper highlights the advantages of various materials used in the removal of hazardous pollutants from wastewater with activated carbon having the highest adsorption capacity. Dyes, pharmaceuticals, endocrine-disrupting chemicals, pesticides and other recalcitrant organic pollutants have been successfully removed at high degradation efficiencies through the photocatalytic process. The photocatalytic degradation and adsorption processes were compared by considering factors such as cost, efficiency, ease of application and reusability. This review will be good resource material for water treatment professionals/scientists, who may be interested in adsorptive and photocatalytic remediation of organic chemicals pollutants.
Topics: Adsorption; Environmental Pollutants; Hazardous Substances; Organic Chemicals; Wastewater; Water Pollutants, Chemical; Water Purification
PubMed: 35533435
DOI: 10.1016/j.jconhyd.2022.104019 -
Molecules (Basel, Switzerland) Nov 2022Solid Phase Adsorption Toxin Tracking (SPATT) and Polar Organic Chemical Integrative Sampler (POCIS) are in situ methods that have been applied to pre-concentrate a... (Review)
Review
A Review of In Situ Methods-Solid Phase Adsorption Toxin Tracking (SPATT) and Polar Organic Chemical Integrative Sampler (POCIS) for the Collection and Concentration of Marine Biotoxins and Pharmaceuticals in Environmental Waters.
Solid Phase Adsorption Toxin Tracking (SPATT) and Polar Organic Chemical Integrative Sampler (POCIS) are in situ methods that have been applied to pre-concentrate a range of marine toxins, pesticides and pharmaceutical compounds that occur at low levels in marine and environmental waters. Recent research has identified the widespread distribution of biotoxins and pharmaceuticals in environmental waters (marine, brackish and freshwater) highlighting the need for the development of effective techniques to generate accurate quantitative water system profiles. In this manuscript, we reviewed in situ methods known as Solid Phase Adsorption Toxin Tracking (SPATT) and Polar Organic Chemical Integrative Sampler (POCIS) for the collection and concentration of marine biotoxins, freshwater cyanotoxins and pharmaceuticals in environmental waters since the 1980s to present. Twelve different adsorption substrates in SPATT and 18 different sorbents in POCIS were reviewed for their ability to absorb a range of lipophilic and hydrophilic marine biotoxins, pharmaceuticals, pesticides, antibiotics and microcystins in marine water, freshwater and wastewater. This review suggests the gaps in reported studies, outlines future research possibilities and guides researchers who wish to work on water contaminates using Solid Phase Adsorption Toxin Tracking (SPATT) and Polar Organic Chemical Integrative Sampler (POCIS) technologies.
Topics: Marine Toxins; Adsorption; Environmental Monitoring; Water Pollutants, Chemical; Organic Chemicals; Pesticides; Water; Pharmaceutical Preparations
PubMed: 36431996
DOI: 10.3390/molecules27227898 -
Accounts of Chemical Research Feb 2000The roles of organic synthesis in chemical ecology are discussed, with many examples. The structure, including the absolute configuration, of a semiochemical (signal... (Review)
Review
The roles of organic synthesis in chemical ecology are discussed, with many examples. The structure, including the absolute configuration, of a semiochemical (signal substance) can be established by enantioselective synthesis. Only through synthesis can a semiochemical be obtained in an amount sufficient for decisive biological evaluation. Rigorous enantioselective synthesis of semiochemicals to provide their pure enantiomers has shown that they are not always enantiomerically pure. Synthesis of the stereoisomers of semiochemicals has clarified their structure-bioactivity relationships to reveal the unprecedented diversity in the stereochemical aspects of pheromone communications.
Topics: Animals; Chemistry, Organic; Ecology; Humans; Organic Chemicals; Organic Chemistry Phenomena; Pheromones; Stereoisomerism
PubMed: 10673318
DOI: 10.1021/ar990006x -
Chemosphere May 2016Activated persulfate reactions have widespread application for groundwater and environmental remediation, as many of these reactions involve destruction of environmental... (Review)
Review
Activated persulfate reactions have widespread application for groundwater and environmental remediation, as many of these reactions involve destruction of environmental contaminants. Within the last five years, knowledge of activated persulfate degradation reactions has grown to include novel means of activating persulfate for enhanced removal of organic species. These current studies cover a long list of organic analytes, including pharmaceuticals, pesticides, halogenated compounds and dyes. An extensive review of recently published experimental parameters and results for the destruction of organic compounds via activated persulfate is presented. Focus is placed on emerging methodologies and manipulation of traditional activation techniques. Knowledge gaps are identified and discussed, as despite the number of publications on this subject, more broad-reaching guidelines are needed for optimizing applications of activated persulfate in water treatment.
Topics: Groundwater; Organic Chemicals; Sulfates; Water Pollutants, Chemical; Water Purification
PubMed: 26938680
DOI: 10.1016/j.chemosphere.2016.02.055 -
Water Research Jul 2022Semi-quantitative GC-MS and LC-MS measurements of organic chemicals in groundwater and surface waters were used to assess the overall magnitude and contribution of the...
Semi-quantitative GC-MS and LC-MS measurements of organic chemicals in groundwater and surface waters were used to assess the overall magnitude and contribution of the most important substances to calculated mixture hazard. Here we use GC-MS and LC-MS measurements taken from two separate national monitoring programs for groundwater and surface water in England, in combination with chronic species sensitivity distribution (SSD) HC50 values published by Posthuma et al. (2019, Environ. Toxicol. Chem, 38, 905-917) to calculate individual substance hazard quotients and mixture effects using a concentration addition approach. The mixture analysis indicated that, as anticipated, there was an increased hazard from the presence of a cocktail of substances at sites compared to the hazard for any single chemical. The magnitude of the difference between the hazard attributed to the most important chemical and the overall mixture effect, however, was not large. Thus, the most toxic chemical contributed ≥ 20% of the calculated mixture effect in >99% of all measured groundwater and surface water samples. On the basis of this analysis, a 5 fold assessment factor placed on the risk identified for any single chemical would offer a high degree of in cases where implementation of a full mixture analysis was not possible. This finding is consistent with previous work that has assessed chemical mixture effects within field monitoring programs and as such provides essential underpinning for future policy and management decisions on how to effectively and proportionately manage mixture risks.
Topics: Environmental Monitoring; Groundwater; Organic Chemicals; Water; Water Pollutants, Chemical
PubMed: 35635919
DOI: 10.1016/j.watres.2022.118641 -
Advanced Materials (Deerfield Beach,... Apr 2013
Topics: Electronics; Materials Testing; Organic Chemicals
PubMed: 23554127
DOI: 10.1002/adma.201205216