Harmful Contaminants Research Articles

Capillary-Assisted Fabrication of Thin-Film Nanocomposite Membranes for Improved Solute-Solute Separation.

Efficient separation of harmful contaminants (e.g., per- and polyfluoroalkyl substances, PFASs) from valuable components (water and nutrients) is essential to the resource recovery from domestic wastewater for agricultural purposes. Such selective recovery requires precise separation at the angstrom scale. Although nanofiltration (NF) has the potential to achieve solute-solute separation, the state-of-the-art polyamide (PA) membranes are typically constrained by limited precision of solute-solute selectivity and their well-documented permeability-selectivity trade-off. Herein, we present a novel capillary-assisted interfacial polymerization (CAIP) approach to generate metal-organic framework (MOF)-PA nanocomposite membranes with reduced surface charges and more uniform pore sizes that favor solute selectivity by enhanced size exclusion. By uniquely regulating the PA-MOF interactions using the capillary force, CAIP results in effective exposure of MOF nanochannels on the membrane surface and a PA matrix with a high cross-linking gradient in the vertical direction, both of which contribute to an exceptional water permeance of ∼18.7 LMH/bar and an unprecedentedly high selectivity between nutrient ions and PFASs. Our CAIP approach breaks new ground for utilizing nanoparticles with nanochannels in fabricating the next-generation, fit-for-purpose NF membranes for improved solute-solute separations.

Reviewing textile wastewater produced by industries: characteristics, environmental impacts, and treatment strategies

Abstract The textile industry is one of the most intensive industries in chemical products whose wastewater contains hazardous dyes, pigments, dissolved/suspended solids, and heavy metals. Hence, it is important to effectively treat the wastewater generated by this industry before releasing it into the environment. Although the field of textile wastewater treatment has made tremendous progress, the developed treatment methods should be improved further to make them economically viable and friendly. In this review, characteristics of textile wastewater are introduced. We have primarily focused on the environmental impact and toxicity of textile wastewater. Toxic and harmful contaminants must be removed from textile wastewater to reduce the extent of environmental pollution caused when textile wastewater is released into rivers or reused. Hence, various techniques that are used to treat textile wastewater are discussed. Finally, the challenges faced, and prospects of the methods have been discussed in detail.

The effects of microplastics in oceans and marine environment on public health – a mini-review

Plastic’s versatility is one reason why production or use has not decreased over the years. The production of plastic globally was 359 million metric tons as of 2018, and this number increased by 3.5% in 2019. Microplastics, which are tiny particles of various types and forms of plastic, can be found in cosmetics, fabrics, car parts, machinery, footwear,products packaging, polythene bags and so on. Over time, these particles, through the process of wear and tear of these various plastic products, indiscriminate disposal, runoffs, and erosion, find their way into water bodies from rivers and streams into larger water bodies like seas and oceans. These tiny non-biodegradable particles find their way into living organisms carrying along with them other harmful chemical contaminants. This study reviews the effects that microplastics found in marine environments have on public health in general. It covers the types and sources of microplastics and the various ways in which microplastics have affected human health and different aquatic species in the marine environment. The review showed all pointers of microplastics present in the environment to have negative impacts on the ecosystem. Certain research gaps are pointed out, like the integration of researchinto policies to help improve the environment and the standardization of dedicated procedures and methods of reporting microplastic pollution. Suggestions were made for possible solutions like the reduction of plastic use for product packaging, provision of biodegradable and eco-friendly materials as substitutes, and general public awareness on the harm of microplastic pollution in the immediate environement.

Simplified and Detailed Analysis of Data Center Particulate Contamination at Server and Room Level Using Computational Fluid Dynamics

Abstract Continuous rise in cloud computing and other web-based services propelled the data center proliferation seen over the past decade. Traditional data centers use vapor-compression-based cooling units that not only reduce energy efficiency but also increase operational and initial investment costs due to involved redundancies. Free air cooling and airside economization can substantially reduce the information technology equipment (ITE) cooling power consumption, which accounts for approximately 40% of energy consumption for a typical air-cooled data center. However, this cooling approach entails an inherent risk of exposing the ITE to harmful ultrafine particulate contaminants, thus, potentially reducing the equipment and component reliability. The present investigation attempts to quantify the effects of particulate contamination inside the data center equipment and ITE room using computational fluid dynamics (CFD). An analysis of the boundary conditions to be used was done by detailed modeling of ITE and the data center white space. Both two-dimensional and three-dimensional simulations were done for detailed analysis of particle transport within the server enclosure. An analysis of the effect of the primary pressure loss obstructions like heat sinks and dual inline memory modules inside the server was done to visualize the localized particle concentrations within the server. A room-level simulation was then conducted to identify the most vulnerable locations of particle concentration within the data center space. The results show that parameters such as higher velocities, heat sink cutouts, and higher aspect ratio features within the server tend to increase the particle concentration inside the servers.

CTV Based Sensor for the Detection of Ni2+ Ions With Real Sample Analysis Based on Mechanism of Fluorescence Along with Computational Insights.

Identification and detection of harmful contaminants such as nickel and other materials from soil and water is critical necessity at the present moment. So with this motive to detect and identify harmful pollutants, a novel cyclotriveratrylene based derivative was prepared for the detection and binding of harmful pollutants which had the properties of fluorescence. The newly derivative of Cyclotriveratrylene was found to be highly sensitive and selective towards Ni2+ ions. The complexation behaviour of this newly synthesised molecule was studied in presence of transition elements. Also computational methods such as docking, molecular modelling and DFT were used to study the molecular orbitals and energies of CTG-NBEP. The detection of Ni2+ from water samples were also carried out successfully.

Effects of Thermal Barrier Coating Using Various Dosing Levels of Aluminium Oxide Nanoadditive Fuel on Diesel in Compressed Ignition Engine

Environmental effects of vehicle exhausts from internal combustions engines which accounts for about 90% of vehicles on the roads is posing a major threat to environmental safety, and it only continues to surge at an alarming rate now than ever. With diesel engines being the most cost‐effective prime mover readily available, their contribution to environmental pollution problems is humongous. The harmful contaminants from diesel exhausts are particulate matter (PM) and hydrocarbon and nitrogen oxides (NOx). So, efforts to curb environmental pollution are the need of the hour by making necessary improvements to reduce their local and global environmental impact. In this study, examine the effects of yttria‐ and alumina‐stabilised zirconia coating on the piston head and cylinder lining of a single‐cylinder diesel engine, as well as its performance and emissions. Various dosing amounts of nanoparticles of aluminium oxide were utilised as additives to diesel fuel in this study, on both coated and uncoated internal combustion engines. Many coated engine metrics improved significantly as a result of the research. The brake thermal efficiency has increased by 2.1 percent as compared to a conventional uncoated diesel engine, while brake‐specific consumption has dropped by 3%, resulting in a reduction in dangerous chemicals.

Экономические, экологические и технические особенности проектирования автомобильных дорог в условиях линзовых (островных) мерзлот

This paper addresses the characteristics of road design under permafrost conditions. Economic and mathematical calculations were used along with practical experience of “Svaybur” and “Gidrostroiengineering” companies, involved in road construction and maintenance for a long period. The prices for construction materials for economic and mathematical calculations were determined using the Integrated Construction Price Standards for Capital Construction Projects for Non-Production Uses. ICP 81-02-08-2017. Collection No. 08: Roads. The environmental requirements were based on the recommended practices developed by the Federal Agency “Rosavtodor”. The cost of maintaining and reconstructing a damaged section of road can exceed by several times the estimated construction cost of the whole section, as well as hinder the logistics and transport accessibility of the agricultural land. In some cases, the environment of the surrounding land may be adversely affected, since harmful contaminants that under normal conditions are bound by the top and bottom structures of the road are released into the soil due to its erosion. The paper examines the economic and environmental problems of designing roads connecting important logistics centres under insular permafrost and permafrost conditions. Here, the calculation of construction costs for road reinforced using screw piles if necessary to prevent the erosion of some road sections during spring floods or heavy precipitation is presented, along with a comparative analysis of construction costs for roads under insular permafrost and permafrost conditions.

Preserving snapper spinach (Amaranthus hybridus) using ozone technology and cold temperature

Indonesia has abundant natural resources, one of which is agricultural products. One of the abundant agricultural products in Indonesia is snapper spinach (Amaranthus hybridus) which contains various kinds of nutrients. Snapper spinach can contain harmful contaminants, one of which is E. coli bacteria. These bacteria can cause snapper spinach to rot easily, so it needs to be removed or reduced. This study aims to determine the effect of ozone and/or cold temperatures on the shelf-life quality of snapper spinach (Amaranthus hybridus). The research methods include the preparation process, the washing process, the storage process (using ozone, cold temperatures, and cold ozone). The results of the study were tested using the TPC test. The best research result is that the process of adding cold temperatures after the ozone method treatment is very influential both in terms of physical and in terms of microbial contamination, seen in samples treated with ozone washed using water and stored at cold temperatures looks better than those stored at room temperature.

UV Light Photo-Degradation of Rhodamine B and Methylene Blue Dyes using Gd2O3 Nanoparticles

The detoxification of numerous harmful and toxic contaminants as well as water treatment is done successfully by photocatalytic oxidation. The potential uses of metal oxide, which are defined as charge carriers in electronic structure, enhance its light-absorbing qualities when exposed to a particular type of radiation and enable its use as a photocatalyst. Metal oxide nanoparticles, as photocatalyst, are used in waste-water treatment in removing pollutants and the degradation of dyes, thus can render water reusable. In the current investigation, XRD and SEM studies were utilized to analyze the rare earth Gd2O3 nanoparticles that were synthesized using the chemical precipitation approach. Additionally, degradation of Rhodamine B and methylene blue in aqueous solution under UV light was used to assess the photocatalytic activity. The results indicated that the synthesized Gd2O3 material exhibits good photocatalytic activity.

Оценка качества базовых масел, полученных по технологии регенерации из отработанных смазочных материалов

The API 1509 standard contains a list of technological processes that can be used to obtain base oils. Base oils can also be obtained using the technology of multistage regeneration of wasted oils. The main requirement according to the classification of API standard 1509 is that the re-refined base oil must be free from harmful substances and contaminants that were formed during its previous use. There is no other information in the standard regarding the requirements for re-refined base oils. The article discusses various methods of assessing the quality of industrial batches of base oils of group I, obtained according to the licensed technology of the German company Fluid Solutions. The quality assessment was carried out both directly for base oils obtained using the regeneration technology, and for laboratory samples of market grade oils, the compositions of which included regenerated base oils.

Metal ion sensing with graphene quantum dots: detection of harmful contaminants and biorelevant species.

Graphene quantum dots (GQDs) are attractive materials for use as highly selective and sensitive chemical sensors, owing to their simple preparation and affordability. GQDs have been successfully deployed as sensors for toxic metal ions, which is a significant issue due to the ever-increasing environmental contamination from agricultural and industrial activities. Despite the success of GQDs in this area, the mechanisms which underpin GQD-metal ion specificity are rarely explored. This lack of information can result in difficulties when attempting to replicate published procedures and can limit the judicious design of new highly selective GQD sensors. Furthermore, there is a dearth of GQD examples which selectively detect biologically relevant alkali and alkaline earth metals. This review will present the current state of GQDs as metal ion sensors for harmful contaminants, highlighting and discussing the discrepancies that exist in the proposed mechanisms regarding metal ion selectivity. The emerging field of GQD sensors for biorelevant metal ion species will also be reviewed, with a perspective to the future of this highly versatile material.

Quality of Soil in Gossaigaon Sub-Division and Its Impact on Environmental Degradation

People on Earth are under tremendous threat due to undesired changes in the physical, chemical and biological characteristics of water and soil. Due to increased human population, industrialization, use of unwanted amounts of fertilizers and man-made activities, water and soil is highly polluted with different harmful contaminants. Natural water and soil contaminates due to weathering of rocks and leaching of soils, mining processing etc. It is necessary that the quality of drinking water and soil should be checked at regular time interval, because due to use of contaminated drinking water, human population suffers from variety of water borne diseases. The study area, Gossaigaon sub-division of Kokrajhar district, Assam lies on the north bank of the Brahmaputra river and is slowly sloping towards south from the foothills of Bhutan upto an average height of 42 MSL. The tributaries of the Brahmaputra- Sankosh, Ripu, Dambra, Bura chara, Gadadhar, Gurufella, Madati, Hel, Gongea are flowing southward which have their sources in the Himalayas. In this paper an attempt has been made to assess the quality of soil of 10 different stations by considering the parameters like Colour, Temperature, pH value, Conductance, Alkalinity, Dissolved Oxygen, Hardness, TS, TDS, Chlorine, Fluorine, Sulphur, Nitrogen, Phosphorous, Iron, Calcium and Magnesium, Sodium, Potassium, Zinc, Nickel, Lead and Copper which have direct correlation with human health.

Evaluation of Toxicity Effect of Palm Oil Mill Effluent Final Discharge by using Daphnia magna

Palm Oil Mill Effluent (POME) final discharge has a risk to the ecosystem due to various harmful contaminants including organic and inorganic materials. In this study, biological monitoring method was used to evaluate the toxicity effects of POME final discharge using Daphnia magna. The physical and chemical nature of toxicants present in the effluent were characterized through acute Whole Effluent Toxicity (WET), and Toxicity Identification Evaluation (TIE) tests. The Toxicity Unit (TU) and median lethal concentration (LC50) of the POME sample were 11.09 and 9.02% (v/v) respectively. From TIE test, the toxicants present in the effluent can be characterized as filterable and oxidisable through filtration and aeration treatment. The presence of cationic metals, chlorine and disinfection by-products were also determined by the toxicity reduction of the effluent after treatment using ethylenediaminetetraacetic acid (EDTA) and sodium thiosulphate. From TIE test, the filtration treatment at pH 10 of the POME final discharge was the most effective method in reducing the toxicity of the effluent with a value of TU, 1.16 and LC50, 86.34% (v/v). It is recommended that biological tests using Daphnia magna can be made as potential methods to indicate the effects of POME final discharge to the aquatic ecosystem.

Effect of atom transfer radical polymerization reaction time on PCB binding capacities of Styrene-CMA/QMA Core-Shell iron oxide nanoparticles

Water pollution continues to be one of the greatest challenges humankind faces worldwide. Increasing population growth, fast industrialization and modernization risk the worsening of water accessibility and quality in the coming years. Nanoadsorbents have steadily gained attention as remediation technologies that can meet stringent water quality demands. In this work, core–shell magnetic nanoparticles (MNPs) comprised of an iron oxide magnetic core and a styrene based polymer shell were synthesized via surface initiated atom transfer radical polymerization (SI-ATRP) and characterized for their binding of polychlorinated biphenyls (PCBs), as model organic contaminants. Acrylated plant derived polyphenols, curcumin multiacrylate (CMA) and quercetin multiacrylate (QMA), and divinylbenzene (DVB) were incorporated into the polymeric shell to create high affinity binding sites for PCBs. The affinity of these novel materials for PCB 126 was evaluated and fitted to the nonlinear Langmuir model to determine binding affinities (KD). The KD values obtained for all the MNP systems showed higher binding affinities for PCB 126 that carbonaceous materials, like activated carbon and graphene oxide, the most widely used adsorption materials for water remediation today. The effect of increasing ATRP reaction time on the binding affinity of MNPs demonstrated the ability to tune polymer shell thickness by modifying the reaction extent and initial crosslinker concentrations in order to maximize pollutant binding. The enhancement in binding affinity and capacity for PCB 126 was demonstrated by the use of hydrophobic, aromatic rich molecules like styrene, CMA, QMA and DVB, within the polymeric shell provides more sites for π-π interactions to occur between the MNP surface and the PCB molecules. Overall, the high affinities for PCBs, as model organic pollutants, and magnetic capabilities of the core–shell MNPs synthesized provide a strong rationale for their application as nanoadsorbents in the environmental remediation of specific harmful contaminants.

Structure simulation design of a cathode air filter for SO2 contamination on a 7 kW fuel cell sightseeing vehicle

Proton exchange membrane (PEM) fuel cell stacks can be severely poisoned by a trace amount of SO2 in the atmosphere, making it necessary to install an air filter to remove harmful contaminants from the cathode air. This study utilizes Computational Fluid Dynamics (CFD) to investigate the influence of the diverse filter structure design containing combinations of inlet diversion tube length and outlet deflector shape on the hydrodynamics and adsorption performance of a cathode air filter by Fluent. Simulation results show that the air filter performance is enhanced with decreases in diversion tube length. Compared with the horizontal porous plate, the conical one increases the pressure drop and the SO2 adsorption dead zone area. Besides, an air filter prototype made based on the simulation results was applied to a 7 kW fuel cell sightseeing vehicle for the field test. The maximum voltage value of the stack is 73.1 V, the minimum is 67.6 V, and the maximum difference is 5.5 V when the fuel cell sightseeing vehicle runs at a constant speed of 20 km/h 77% of the voltage value is stable between 69 and 71 V, which proves the stable operation of the stack.

Oxidative Degradation of Hazardous Benzene Derivatives by Ferrate(VI): Effect of Initial pH, Molar Ratio and Temperature.

Two of the most hazardous benzene derivatives (HBD) that have polluted the aquatic environment are bromobenzene and chlorobenzene. Ferrate can degrade various pollutants quickly and efficiently without producing harmful byproducts. This study aims to determine the ability of ferrate to degrade harmful contaminants such as bromobenzene and chlorobenzene. A series of batch experiments were carried out, including for the molar ratio, initial pH solution, and temperature. The study was conducted at an initial pH of 3.6 to 9.6, a molar ratio of 2 to 8 and a temperature of 15 to 55 °C. The study will also examine the differences in functional groups in these pollutants. As a result of the experiments, the optimum conditions to oxidize HBD in a batch reactor was found to have an initial pH of 7.0, a molar ratio of 8, and a temperature of 45 °C, with a 10 min reaction time. Ferrate has a degradation ability against chlorobenzene greater than bromobenzene. The functional cluster in pollutants also significantly affects the degradation ability of ferrate. The results of the degradation experiment showed that ferrate(VI) could effectively oxidize hazardous benzene derivatives in a solution.

Heavy metal contamination and antibiotic residues in poultry feed and meat in Bangladesh

Presence of harmful contaminants and residues in poultry feed and meat have serious public health consequence. This study was carried out to identify and quantify antibiotic residues, heavy metals and toxins in poultry feed and meat in the two selected poultry production belts of Bangladesh. A total of 94 broiler feed samples and 60 broiler meat samples were collected and tested by Thin Layer Chromatography (TLC), High Performance Liquid Chromatography (HPLC) and Enzyme-linked Immunosorbent Assay (ELISA) for identification and quantification of the parameters. Antibiotic residues were detected in 18.89% of the feed samples, whereas, there were no toxin (Aflatoxin) positive samples. Among the antibiotic positive samples, Oxytetracycline (OTC) was found predominant and detected in 12.22% cases. The mean concentrations of Cadmium (Cd), Lead (Pb), Chromium (Cr) were found as 0.04 mg/kg, 1.28 mg/kg and 2.55 mg/kg respectively in feed samples. In the case of meat samples, the mean concentration of OTC, Ciprofloxacin (CIP), and Tetracycline (TCL) residues were found 8.67 ppb, 7.18 ppb and 0.81 ppb accordingly. The highest mean concentration of Oxytetracycline (OTC) (10.15 ppb) was found in samples collected from local poultry sellers, whereas, the highest mean concentration of Tetracycline (TCL) (1.35 ppb) and Ciprofloxacin (CIP) (10.62 ppb) were observed in the samples obtained from local farm. The highest percentage of TCL and CIP (64% and 48% respectively) were found in samples collected from local farm. Chlortetracycline (CTC) was found predominant (70%) in samples collected from Contract farms. On the other hand, out of 60 meat samples, Cd and Cr were detected in only one meat sample with concentration of 56.41 mg/kg and 14.44 mg/kg respectively. Lead was not detected in any of the meat samples. Asian Australas. J. Food Saf. Secur. 2021, 5 (2), 71-78

In situ arsenic immobilisation for coastal aquifers using stimulated iron cycling: Lab-based viability assessment

Arsenic (As) is one of the most harmful and widespread groundwater contaminants globally. Besides the occurrence of geogenic As pollution, there is also a large number of sites that have been polluted by anthropogenic activities, with many of those requiring active remediation to reduce their environmental impact. Cost-effective remedial strategies are however still sorely needed. At the laboratory-scale in situ formation of magnetite through the joint addition of nitrate and Fe(II) has shown to be a promising new technique. However, its applicability under a wider range of environmental conditions still needs to be assessed. Here we use sediment and groundwater from a severely polluted coastal aquifer and explore the efficiency of nitrate-Fe(II) treatments in mitigating dissolved As concentrations. In selected experiments >99% of dissolved As was removed, compared to unamended controls, and maintained upon addition of lactate, a labile organic carbon source. Pre- and post-experimental characterisation of iron (Fe) mineral phases suggested a >90% loss of amorphous Fe oxides in favour of increased crystalline, recalcitrant oxide and sulfide phases. Magnetite formation did not occur via the nitrate-dependent oxidation of the amended Fe(II) as originally expected. Instead, magnetite is thought to have formed by the Fe(II)-catalysed transformation of pre-existing amorphous and crystalline Fe oxides. The extent of amorphous and crystalline Fe oxide transformation was then limited by the exhaustion of dissolved Fe(II). Elevated phosphate concentrations lowered the treatment efficacy, indicating joint removal of phosphate is necessary for maximum impact. The remedial efficiency was not impacted by varying salinities, thus rendering the tested approach a viable remediation method for coastal aquifers.

Seasonal Considerations for Year-Round Operation of On-Farm Wetlands in Temperate Climates: A Review

On-farm constructed wetlands (CW) have been increasing in application over the past several decades to treat a variety of agricultural wastewaters. These systems have been found to be relatively low cost, require minimal maintenance, and provide a very efficient and sustainable means of treating harmful contaminants during the warm seasons before reaching nearby waterways. With farm size increasing in many regions and more waste being generated, it becomes increasingly important to have a viable means of treating wastewaters on a year-round basis. However, temperate climates can present challenges in the treatment of these wastewaters. This paper aims to bring together and review previous research on the use of CWs for treating agricultural wastewater in temperate climates where below freezing temperatures can exist. Focus is placed on the use of various wetland designs, wastewater types, management practices, maintenance, operational challenges and overall treatment capacities. This study highlights the need to carefully consider several factors (i.e. waste type, design, climate, vegetation, management) before using these systems for year-round treatment. Continued research in wetland management will be key in getting wide scale adoption from the agricultural community in temperate climates.

Investigation of Filtration Phenomena of Air Pollutants on Cathode Air Filters for PEM Fuel Cells

Filtration of cathode air is one of the challenges in operating proton-exchange membrane (PEM) fuel cells. The poisoning with air contaminants can lead to rapid performance degradation and initiate an aging process of the fuel cell. Various commercially available cathode filters are being tested in a laboratory gas test bench within the research project X-EMU (03B10502B and 03B10502B2). A literature review of harmful gas contaminants in the air used for the oxygen reduction reaction (ORR) on the cathode side was conducted. Experimental investigations took place at 40 °C with synthetic humid air containing low concentration contaminants such as ammonia, nitrogen dioxide, carbon monoxide, sulfur dioxide, hydrogen sulfide, and toluene. Test durations varied from 3 to 24 h depending on the filtration efficiency. Each gas contaminant showed different reactions with the investigated filters. The filters did not let sulfur-containing components pass. However, carbon monoxide could not be filtrated by any of the tested filters. The filtration of nitrogen oxides was not efficient for all tested filters, while additional filter materials were essential for a successful filtration of ammonia. Comparative results lead to a discussion of possible effects on a fuel cell with an outlook on optimization of the filtration behavior.