Environmental Management
S. Kasim; A. Daud; A.B. Birawida; A. Mallongi; A.I. Arundana; A. Rasul; M. Hatta
Abstract
BACKGROUND AND OBJECTIVES: Microplastic pollution has a far and wide presence in the surroundings. It can be encountered in the sea, wastewater, freshwater, food, air, and water sources. It is even present in refilled drinking water. This study aims to analyze environmental health dangers of the exposure ...
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BACKGROUND AND OBJECTIVES: Microplastic pollution has a far and wide presence in the surroundings. It can be encountered in the sea, wastewater, freshwater, food, air, and water sources. It is even present in refilled drinking water. This study aims to analyze environmental health dangers of the exposure to polyethylene terephthalate microplastics in refilled water sources in Tamangapa, Makassar City, Indonesia.METHODS: This research is an observational study with an environmental health risk analysis. Sampling was conducted in Tamangapa, Makassar City, Indonesia. A total of 100 respondents were involved. Additionally, 20 samples of refilled drinking water were examined in the laboratory using the Fourier Transform Infrared test. Data analysis was carried out by calculating the intake and risk quotient values. If risk quotient > 1, it is considered necessary to carry out risk management.FINDINGS: An average polyethylene terephthalate microplastic concentration of 0.0052 milligram per kilogram per day, an average intake rate of 210 milligrams per kilogram per day, an average exposure frequency of 350 days, an average exposure duration of 30 years, average intake exposure to polyethylene terephthalate microplastics above 0.0004, and an average risk quotient value above 1 were obtained. If they build up in the body, microplastics may have harmful consequences, including organ inflammation, internal or external damage, and chemical alteration of plastics that have already entered the body.CONCLUSION: Some measures of risk management that can be performed are to reduce the concentration of risk agents if the pattern and timing of consumption cannot be changed, reduce the consumption pattern (intake rate) if the concentration of risk agents and the time of consumption cannot be changed, and reduce the contact time if the risk agent concentration and consumption pattern cannot be changed.
Environmental Engineering
R.G. Sarmurzina; G.I. Boiko; B.K. Kenzhaliyev; U.S. Karabalin; N.P. Lyubchenko; P.V. Kenyaikin; Zh.B. Ilmaliyev
Abstract
BACKGROUND AND OBJECTIVES: The reduction of fresh water deficit and water-related morbidity is the most important problem of the state’s national security. The effective treatment of natural water in industrialized areas from natural and anthropogenic pollutants is the main ecological task. Coagulation ...
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BACKGROUND AND OBJECTIVES: The reduction of fresh water deficit and water-related morbidity is the most important problem of the state’s national security. The effective treatment of natural water in industrialized areas from natural and anthropogenic pollutants is the main ecological task. Coagulation is one of the effective methods used to treat water chemically to purify it. Aluminum polyoxychlorides have gained popularity because of their advantages over coagulants—aluminum and iron sulfates. No production of aluminum polyoxychloride occurs in Kazakhstan despite the need for coagulants (the minimum need is assessed at about 11 thousand tons). The work is aimed at theoretical justification and experimental proof of a principally new approach to the development of aluminum polyoxychloride production technology based on activated aluminum alloys containing metal activators, such as gallium, indium , and tin from 0.5 to 5 percent weight. In addition, the goal is solving environmental issues associated with improving the drinking water quality and related to environmental pollution with wastewater.METHODS: The microstructures, phase components, and elemental compositions of alloys and reaction products were studied by scanning electron microscopy/energy dispersive X-ray spectroscopy. The thermal effects of alloys were investigated usin thermogravimetry methods. Oil content in wastewater was determined by spectrophotometry. Oil particle dimensions and wastewater zero potentials were determined using electrophoretic light scattering method and residual turbidity by turbidimetry. Water quality assessment was included in the purified water analysis and comparison with the sanitary and epidemiological standards established for drinking water supply and wastewater intended for water discharge.FINDINGS: The structures and compositions of activated aluminum alloy containing metal activators - gallium, indium, and tin - from 0.5 to 5 weight percent and aluminum polyoxychlorides based on it were studied using modern instrumental methods. The efficiency of the treatment of natural and oil-contaminated wastewater with aluminum polyoxychloride was assessed. The treated water parameters were within the norms established for drinking water supply and wastewater disposal by Sanitary Rules and Norms 2.1.4.559-96. The efficiency of potable water treatment reached 90–99 percent.CONCLUSION: An effective and technologically simple method is developed for producing aluminum polyoxychloride. It involves dissolving an activated alloy in 1–5 percent hydrochloric acid, with an aluminum content of 98.5–85 percent. Alloy processing is carried out at temperatures ranging from 60 to 65 degree celsius. The temperature rises from 20 to 25 degree celsius to the specified optimum without heat supply from the outside due to the interaction among reagents. The process is completed in 2–3 hours. The results confirm that aluminum polyoxychloride is an effective coagulant for drinking and wastewater treatment. The treated water is within the established limits in terms of hydrogen potential, chemical oxygen demand, and turbidity. The water treatment method can be easily implemented.
Environmental Science
G. Manjarrez Paba; R. Baldiris Ávila; D. Baena Baldiris
Abstract
BACKGROUND AND OBJECTIVES:The objective of this study isto present a description of the main characteristics of azo dyes and the different treatment methods used to remove them from water. There is a special emphasis given to the benefits associated with biological treatment, predominantly those related ...
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BACKGROUND AND OBJECTIVES:The objective of this study isto present a description of the main characteristics of azo dyes and the different treatment methods used to remove them from water. There is a special emphasis given to the benefits associated with biological treatment, predominantly those related to the use of bacteria, which has to do with its competitive advantages over other microorganisms in the dye degradation processes.METHODS: The topic to be addressed was first defined through workshops with the research group. The literature review was carried out following several inclusion/exclusion criteria: the year of publication, as the selection was limited to studies published between 2010 and 2020, the focus of the investigation, which had to be related to the efficiency of different techniques for the remediation of ecosystems contaminated with azo dyes and, lastly, that the studies also discussed the use of environmental bacteria in dye degradation processes.FINDING: The efficiency of bacteria to degrade azo dyes ranges from 63-100%, the most efficient being: Marinobacter sp, Sphingobacterium sp, Enterococcus faecalis, Enterococcus casseliflavus. The bacteria that, reportedly, have greater efficiency for simultaneously removing the dye-metal complex are Bacillus circulans and Acinetobacter junii.CONCLUSION: Traditional strategies for the treatment of effluents contaminated with azo dyes are limited to physical and chemical processes that have a high energy and economic cost. For these reasons, current challenges are focused on the use of environmental bacteria capable of transforming dyes into less toxic compounds.
M. Keshvardoostchokami; L. Babaei; A.A. Zamani; A.H. Parizanganeh; F. Piri
Abstract
In this study, an easy synthesized method for preparation of chitosan/iron oxide nanocomposite as a bio-sorbent has been applied. Analytical techniques such as Fourier transform infrared spectroscopy, X-ray diffraction; Field emission scanning electron microscopy and transmission electron microscopy ...
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In this study, an easy synthesized method for preparation of chitosan/iron oxide nanocomposite as a bio-sorbent has been applied. Analytical techniques such as Fourier transform infrared spectroscopy, X-ray diffraction; Field emission scanning electron microscopy and transmission electron microscopy were utilized to survey of morphological structure and the functional groups characterization. The histogram of frequency of particle size confirmed that medium size of the synthesized nanoparticles was 50 nm. Beside the obtained nanocomposite, application of chitosan as the precursor and shrimp shell as natural chitin and a natural polymer were assessed as adsorbents for decontamination of Ni2+, Cd2+ and Pb2+ as examples of heavy metals from drinking water. Batch studies were performed for adsorption experiments by changing variables such as pH, contact time and adsorbent dose. Based on the experimental sorption capacities, 58, 202 and 12 mg of Ni, Cd and Pb per g of Chitosan-Fe2O3 nanocomposite as adsorbent respectively, confirm that combination of Fe2O3 nanoparticles with chitosan makes a more efficient adsorbent than chitosan and chitin. Adsorbents in uptake of the mentioned heavy metals are in the order of Chitosan-Fe2O3 nanocomposite > chitosan> chitin. In addition, the kinetics and isotherm investigations were surveyed. Moreover, it has been shown that the synthesized nanocomposite significantly reduces the amount of the mentioned ions from the real wastewater sample.