Long-term Environmental Pollution Research Articles

Application of Polylactic Acid in Clinical Medicine

Polylactic acid (PLA), a bio-based and biodegradable material, shows significant potential in environmental protection and clinical medicine. Derived from renewable resources, PLA's biodegradability reduces long-term environmental pollution by allowing it to decompose rapidly under specific conditions. This review explores PLA's applications in clinical medicine, emphasizing its mechanical properties, biocompatibility, and controlled degradation rates. The study covers PLA's extensive use in drug delivery systems, absorbable sutures, and tissue engineering scaffolds, highlighting its compatibility with human tissues and low immunogenicity. Research methods and designs, including in vitro and in vivo experiments, are discussed to evaluate PLA's efficacy and safety. The challenges of high production costs and specific degradation conditions are also addressed. Future research directions include developing new catalysts to improve synthesis efficiency and exploring renewable raw materials to reduce costs and environmental impact. As global awareness of sustainable development grows, the demand for PLA and other degradable plastics is expected to increase, expanding their applications in various fields. In conclusion, PLA offers substantial advantages in reducing reliance on fossil fuels and mitigating environmental pollution, while providing innovative solutions in the medical field. Technological advancements and increased production are anticipated to lower costs, making PLA more economically competitive and accelerating its application in both environmental protection and clinical medicine.

Life cycle assessment of recycling waste crystalline silicon photovoltaic modules: A comparison between traditional and green solvent recycling processes

Crystalline silicon photovoltaic (PV) modules that have reached the end of their service life, if not effectively recycled, result in the loss of valuable resources such as silicon, silver, aluminum, and others. Moreover, improper disposal can lead to long-term environmental pollution. Therefore, the development of efficient and green recycling technologies for waste PV modules has become a key focus of current research. In this study, a life cycle assessment (LCA) of green solvent recycling (GSR) and traditional recycling technologies was conducted using the ReCiPe 2016 Mid-point evaluation method. The energy and resources consumed, along with the environmental impacts generated, were comparatively analysed, and their resource recovery benefits were calculated. Results show that GSR performs well in terms of environmental impact and even better in terms of resource recovery benefits. Leaching with 1,3-dimethyl-2-imidazolidinone (DMI) solvents reduces global warming potential by 487 kg CO2 eq compared to nitric acid used in chemical recycling. Deep eutectic solvents (DES) achieve higher leaching rates of up to 99 %, compared to metals recovered via mechanical separation, and reduce terrestrial ecotoxicity by 742 kg of 1,4-DCB. Of all energy and resource inputs, electricity consumption contributes the most to environmental impacts. In summary, this study offers a more environmentally friendly and effective recycling solution for the PV industry, supporting its green transformation and sustainable development.

Isolation of High Density Polyethelene Degradating Bacteria from Soil

Plastics are the most commonly used polymers for routine applications. These plastics are less biodegradable in the environment. So the plastics accumulated drastically in the environment and had bad effects on it. High-density polyethylene (HDPE) is a major cause of persistent and long-term environmental pollution. The main objective of the present study is the isolation and screening of bacterial species with the capability to degrade high-density polyethylene (HDPE). The two bacterial isolates were identified from soil collected from the dumping yard of village Atake (Tal-Karad, Dist-Satara). These two bacterial isolates were obtained on minimal agar medium incorporated with HDPE. These isolates are further tested for degradation of the plastic. The isolate 1 (Bacillus cereus) could degrade the plastic to the extent of 16% in terms of % weight loss, while the isolate 2 (Pseudomonas halobacterium) could degrade the plastic to the extent of 10% in terms of % weight loss, thus the isolate 1, which was identified as Bacillus cereus was found to be the best among the two isolates.

Investigating the impact of GDP, energy mix, energy intensity, and the service sector on environmental pollution in MENA countries: An application of Driscoll-Kraay standard error approach

The goal of this study is to explore the stochastic impacts of population, GDP, renewable energy, fossil fuels, energy intensity, and the service sector on environmental pollution through regression analysis. To achieve this goal, this study employed the Driscoll-Kraay standard error approach for the “Middle East and North African (MENA)” countries. The study assured a balanced panel of data from 1997 to 2021 and applied the STIRPAT model to test which variables are responsible for environmental pollution in the MENA region. The study's findings show that factors such as population size, gross domestic product, the use of fossil fuels, and energy intensity all contribute to environmental pollution. On the other hand, using renewable energy and strengthening the service sector can reduce long-term environmental pollution. The study's findings have proposed various policy implications for MENA countries to reduce environmental pollution, including carbon and greenhouse gas (GHG) emission mitigation, considering sustainable development goals 7 and 13.

ENCAPSULATION OF GROUND BOTTOM ASH AS SUPPLEMENTARY CEMENTITIOUS MATERIALS FOR CEMENT MORTAR

Excessive carbon dioxide (CO2) emissions due to the Portland cement manufacturing process have encouraged the industry to look for more sustainable alternatives to cement. Supplementary cementitious material (SCM) has been widely used to improve concrete performance through considerable research. By-product waste, such as fly ash, has been utilized in many construction projects. It is an effective solution to solve long-term environmental pollution. As one of the coal industry by-products, bottom ash has similar chemical properties compared to fly ash, but it is rarely used as SCM because of its size. Therefore, this research aims to modify the regular bottom ash and observe the strength development of cement mortar incorporating bottom ash as SCM. The pre-treatment process of bottom ash was performed by 4 hours of milling to produce micro-size particles. The chemical and physical properties of modified bottom ash were evaluated before being cast into cement mortar specimens. Various percentages of cement replacement using modified bottom ash were used in this research. The evaluations include X-ray fluorescence (XRF) analysis, specific gravity, particle size analysis, scanning electron microscope-energy dispersive X-ray (SEM-EDX), normal consistency, and setting time. The compressive strength and strength activity index were evaluated to obtain the strength development and optimum composition of cement mortar incorporating bottom ash, caused by pozzolanic activity. The results indicate that bottom ash positively affects the strength development of cement mortar, and it can be used as SCM to produce more sustainable cement-based construction materials.

Can environmental regulations change the environmental behaviour of local leaders and enterprises? Evidence using the accountability audit of natural resources in China

ABSTRACT Securing long-term environmental pollution control in a system where local leaders in China hold tenure for only a short term is a challenge. The innovative Chinese accountability audit of natural resources (AANR) pilot project attempts to address this problem by mandating lifelong accountability for local leaders. Using this pilot as a quasi-natural experiment, we explored macro-effectiveness and micro-mechanisms of AANR. The results show that AANR has a positive impact on the environmental investment behaviour of enterprises. This paper finds that AANR stimulates enterprises’ investments in the environment by improving the environmental behaviour of local leaders. During mobilisation meetings, local leaders convey signals on environmental matters. Political connections are bridges which convey the signals of mobilisation to enterprises. Those enterprises receive the signals and increase environmental investment. AANR thus promotes collaborative governance by ensuring that the interests of key stakeholders are aligned to prevent pollution.

Quality Assessment of Composts from different Organic sources

Currently, environmental pollution is a global issue that is directly or indirectly related to human activities. Uses of chemical fertilizer also cause long-term environmental pollution. Concerning this, the composting technique for the management of organic waste is a good deal. This method or technique is better than chemical fertilizers as it is eco-friendly and environmentally friendly. The use of compost depends on its different quality parameters. The presented study shows the comparative analysis of three types of compost which were prepared by windrow type of composting. Composts were differentiated based on their organic matter source. Analysis of compost quality was done based on their macronutrient – Nitrogen, Phosphorus, and Potassium and the physical composition of compost. The result shows that all three types of composts match the quality standard of the Indian Fertilizer Control Order-1985. Compost from vegetable waste contains more nutrients as compared to others. All three were very less different in their nutrient composition. By comparing the composting time duration fruit waste is converted into compost earlier than others. This shows that vegetable waste gives high-quality compost that can be used as organic fertilizer. Fruits and farm waste are also useful but vegetable wastes give better quality compost concerning macronutrients.

Effect of an Acinetobacter pittobacter on low-density polyethylene.

Low-density polyethylene (LDPE) is a major cause of persistent and long-term environmental pollution. In this study, we report the successful isolation of an efficient LDPE degrading bacterial strain from the wastewater sediment of an agricultural land film recycling plant and identified and designated it as Acinetobacter sp. LW-1, respectively. The surface analyses including scanning electron microscopy (SEM) and atomic force microscopy (AFM) of LW-1-treated samples revealed the existence of appreciable pits and cavities on the facet of PE film, while the formation of carbonyl group was also verified by XPS and FTIR. Moreover, water contact angle assay substantiated the chemical transformation of the LDPE film from hydrophobic to hydrophilic transition after treatment with LW-1. In addition, co-incubation of LDPE film and Acinetobacter sp. LW-1 at 35°C for 90days significantly decreased the weight of LDPE film with an optimal weight loss of 15 ± 0.85%. This work enriches the LDPE degradation bacterial library and shows the tremendous potential of Acinetobacter sp. LW-1 to be used in the degradation of LDPE waste.

Bacterial diversity and competitors for degradation of hazardous oil refining waste under selective pressures of temperature and oxygen

Oil refining waste (ORW) contains complex, hazardous, and refractory components, causing more severe long-term environmental pollution than petroleum. Here, ORW was used to simulate the accelerated domestication of bacteria from oily sludges and polymer-flooding wastewater, and the effects of key factors, oxygen and temperature, on the ORW degradation were evaluated. Bacterial communities acclimated respectively in 30/60 °C, aerobic/anaerobic conditions showed differentiated degradation rates of ORW, ranging from 5% to 34%. High-throughput amplicon sequencing and ORW component analysis revealed significant correlation between bacterial diversity/biomass and degradation efficiency/substrate preference. Under mesophilic and oxygen-rich condition, the high biomass and abundant biodiversity with diverse genes and pathways for petroleum hydrocarbons degradation, effectively promoted the rapid and multi-component degradation of ORW. While under harsh conditions, a few dominant genera still contributed to ORW degradation, although the biodiversity was severely restricted. The typical dominant facultative anaerobes Bacillus (up to 99.8% abundance anaerobically) and Geobacillus (up to 99.9% abundance aerobically and anaerobically) showed oxygen-independent sustainable degradation ability and broad-spectrum of temperature adaptability, making them promising and competitive bioremediation candidates for future application. Our findings provide important strategies for practical bioremediation of varied environments polluted by hazardous ORW.

Nanocellulose in the food industry and medicine: structure, production and application

Cellulose is the most abundant polymer in the biosphere and has many technical applications, including food production. The development of cellulose technology in the 21st century has led to the emergence of nanocellulose (NC), which has widely varying chemical and physical properties and, therefore, has fundamentally new areas of application in biomedicine and the food industry. The aim of this work is to review the literature on the structure, sources, methods for obtaining nanocelluloses, including methods for their chemical modification, current and prospective applications in the food industry, packaging materials, biomedicine, etc. Material and methods. For the analysis, sources were selected mainly for the period from 2014 to 2022, contained in the international databases PubMed, WoS and Scopus and meeting the requirements of scientific reliability and completeness. Results. Among the main types of NC there can be identified nanofibrous cellulose (NFC), consisting of fibers longer than 500 nm and about 10-20 nm thick, and nanocrystalline cellulose (NCC) with particles 100-500 nm long and less than 100 nm in diameter. A special group of materials includes bacterial NC (BNC) produced by microorganisms and representing entangled coils or layers of cellulose fibers with a thickness of less than 100 nm. Significant changes in the physical, chemical and functional properties of NC can be achieved by its physical and chemical modification, which leads to a change in swelling, an increase in the mechanical strength and stability of hydrogels, and compatibility with synthetic polymers. NFC, NCC and BNC are offered as food ingredients for inclusion both in mass consumption products and in specialized foods for dietary and therapeutic uses, as well as in the so-called «functional products», for which manufacturers declare the ability to influence actively on the state of intestinal microflora and digestive function. In biomedical applications, of great interest is the biocompatibility of BNC with various cell types in combination with biodegradability, which makes it possible to create new types of materials for reconstructive surgery, effective and safe dressings. When used as packaging materials, NC products successfully compete with synthetic polymers without causing long-term environmental pollution. Factors hindering the introduction of NC products into practice are the gaps of knowledge of NC biological action, combined with the risks caused by possible residual amounts of chemicals and biochemical reagents, bacterial toxins, enzyme preparations and microorganisms-producers in the composition of NC. Conclusion. There is an important task to develop a system for regulating NCs and products with its content, in accordance with the technical regulations of the Customs Union of the EAEU.

A study on microbial deterioration of low-density polyethylene

Plastics have been widely used as a packing material in the form of low-density polyethylene (LDPE) they are very versatile in nature, cost efficient and facile. However, they are not decomposable and resistant to microbial attack which is a major cause of persistent and long-term environmental pollution. In this study, the isolation of polythene degrading microorganisms was done from plastic wastes dumped site. The effect of the pre-treatment on the biodegradation of polythene was analyzed during one month of incubation period in liquid (shaker) culture method. To check the efficiency of biodegradation, weight method was performed. The bacterial species found associated with the degrading materials were found to be as Gram-positive cocci and Gram-negative rods; and these were identified as Staphylococcus simiae and Proteus vulgaris with the help of an online advanced bacterial identification software. Several biochemical assays were performed to determine the effective biodegradation of polyethylene bags. This work reveals that Proteus vulgaris possess greater potential to degrade polythene as compared to Staphylococcus simiae. Proteus vulgaris showed better degradation efficiency in case of both pre-treated and untreated samples, proving to be a potent microbe in degrading polythene.

Performance and Mechanisms of PropS-SH/HA Coatings in the Inhibition of Pyrite Oxidation

Acid mine drainage (AMD) entering the environment will cause long-term environmental pollution and ecological damage, the treatment or remediation for which has become a difficult worldwide problem. To control AMD at the source, a novel composite coating, hydroxyapatite (HA) as the filler embedded in a γ-mercaptopropyltrimethoxysilane (PropS-SH) coating, was introduced in this study. The performance and mechanisms of PropS-SH/HA coatings in the inhibition of pyrite oxidation were investigated by chemical leaching testing and material structure characterization. The results of the investigations revealed that the addition of an appropriate amount of HA can enhance the passivation efficiency of the PropS-SH coating. The best coating was obtained from 3% (v/v) of PropS-SH solution with 16 wt % HA, as this coating decreased pyrite oxidation by 78.7% (based on total Fe release). The main mechanism of PropS-SH/HA for the inhibition of pyrite oxidation involved the generation of a PropS-SH network through a polycondensation reaction. The addition of HA increased the stability of the passivation film composed of PropS-SH as well as the combining capacity of PropS-SH/HA through the formation of Si–O–Si and Fe–O–Si bonds, respectively.

A Multifaceted Approach for Cryogenic Waste Tire Recycling

One of the important aspects for degradation of the life quality is the ever increasing volume and range of industrial wastes. Polymer wastes, such as automotive tire rubber, are a source of long-term environmental pollution. This paper presents an approach to simplifying the rubber waste recycling process using cryogenic temperatures. The temperature of cryogenic treatment is ranged from 77 K to 280 K. Liquid nitrogen was used as a cryoagent for laboratory tests. Experimental and numerical studies have been carried out to determine the optimal conditions for the recycling process. Numerical studies were performed using the COMSOL Multiphysics cross-platform software. The optimal force of mechanical shock for the destruction of a tire which turned into a glassy state after cryoexposure was determined experimentally. The chemical and physical properties of the final product (crumb rubber) have been studied by scanning electron microscopy and energy dispersive X-ray spectroscopy. The analysis shows that the morphology and elemental composition of the samples remain practically unchanged, demonstrating environmental friendliness of the proposed process.

Ecological risk assessment and long-term environmental pollution caused by obsolete undisposed organochlorine pesticides

Obsolete organochlorine pesticides (OSPs) are currently prohibited as persistent organic pollutants that contaminate the environment. If undisposed, they continue to pollute soil and water, to accumulate in the food chain and to harm plants, animals and the human body. The aim of the study was to assess water and soil pollution around the storehouses of undisposed, banned OSPs and their possible genotoxic effect. The storehouses in four villages near Almaty, Kazakhstan were investigated. Chemical analysis confirmed contamination of water and soil around storehouses with OSPs. The genotoxic effect of water and soil samples was evaluated using model objects: S.typhymurium, D.melanogaster, sheep lymphocytes cultures and human lymphocytes cultures. It was found that water and soil samples caused mutagenic effect in all model systems. They increased the frequency of revertants in Salmonella, the frequency of lethal mutations in Drosophila chromosomes, and the frequency of chromosome aberrations in cultures of human and sheep lymphocytes. Although a genotoxic effect was demonstrated for each of these models, various models showed different sensitivity to the effects of pesticides and they varied degree of response. The association between the total content of OCPs in soil and the level of mutations for different model systems was discovered.

Analysis on the quality system and effect of Environmental Hygiene Surveillance in the Prevention and Control of Infectious Diseases

Whether the nature and task of the actual work of environmental sanitation in our country should be changed or adjusted, at present, the coexistence of environmental vehicle science and environmental medicine in our country, how to treat the situation of the coexistence of environmental health work and environmental protection work and how to deal with it correctly in order to facilitate further development and so on. In essence, these problems are the development direction of environmental hygiene and environmental health work in our country. To study the role of public health surveillance in current disease prevention and control. Analyze the literature to clarify the concept, content and specific role of public health surveillance. The main contents of environmental health monitoring are the prevention of sudden accidents, long-term environmental pollution and the detection of environmental hygiene. Through the effective prevention and evaluation of human disease and health, the normal life and health of residents can be guaranteed. Through the development of effective solutions, we can play the role of public health surveillance and improve the effect of disease prevention and control.

A study on the bacteriological characterization of the coastal Tangier seawater: Preliminary results

This paper deals, on the one hand, with a study of bacteriological parameters of coastal water in the region of Tangier Ksar-Sghir, north of Morocco, and secondly, with an examination of the influence of temperature parameter on biological processes occurring within seawater. The bacteriological study concerns E. coli, fecal coliforms (F.C), total coliforms (T.C) and fecal streptococcus (F.S). A campaign of 25 sampling points spread over four layers of concentration was conducted in the coastal line during the year of 2017 and The overall results of tests were obtained using the Principal Component Analysis method. (PCA). The analysis has highlighted differentiated areas in term of sanitary quality. The highest values obtained were in the zone of Tangier-Med port showing high fecal contamination by pollution indicator bacteria (T.C, F.C, E. coli and F.S) with high temperature values that result in short-, medium- and long-term environmental pollution.

Development and Status of the Treatment Technology for Acid Mine Drainage

Acid mine drainage (AMD) is difficult to treat due to its physicochemical characteristics, such as high pH and high heavy metal concentrations, so it causes great harm to the environment and human health. If acid mine drainage is discharged arbitrarily without treatment, it will lead to a series of environmental problems and cause long-term environmental pollution. In this paper, the source and hazards of acid mine drainage are introduced in detail. And the principle, the mechanism, the application, and basic information of the current primary technology of the treatment for acid mine drainage are comprehensively introduced and summarized. The summarized treatment technologies for acid mine drainage mainly include neutralization, sulfidization, constructed wetland method, adsorption method, microbiological method, ion exchange method, membrane technology, and microbial fuel cell technology. Also, the primary technology of treatment for acid mine drainage is systematically compared and evaluated. Moreover, some suggestions on the development direction of water treatment technology in the future are put forward. This paper provides a scientific reference for scientific and technical works to treat acid mine drainage.

CYTOGENETIC CHANGES IN SCHOOLCHILDREN RESIDING IN ECOLOGICALLY ADVERSE REGIONS OF KAZAKHSTAN

In Kazakhstan, due to the strengthening of the geopolitical role in the international arena and active industrial development, negative environmental impacts have intensified in recent years. Many regions are environmentally unfavorable and carry the risk of an increase in the incidence of living in these conditions of the population. Numerous deviations in the health of the community create the conditions for genetic polymorphism and the growth of certain groups of diseases characteristic of regions with environmental pollution. Long-term environmental pollution is the reason for the increase in the rate of the mutation process and the volume of the genetic load in the human population. The purpose of this study is to show the influence of dominant environmental factors in distant regions of Kazakhstan on cytogenetic disturbances in the body of the younger generation. Students from different schools aged 16 to 18 years living near the Semipalatinsk test site of the East Kazakhstan region and in the Aral region of the Kyzylorda region took part in the studies. The results of the study show that the oral epithelial cells in two-thirds of the examined adolescents living in environmentally unfavorable conditions either near the Semipalatinsk Test Site or in the Aral Sea region of Kazakhstan revealed a wide range of cytogenetic disorders. The most significant percentage of violations associated with the formation of micronuclei, protrusions, and apoptosis, was detected in urban students living 150 km from the Semipalatinsk Test Site. When comparing the data of urban and rural students, the predominant development of cytological disorders was revealed, such as nuclear destruction (karyorrhexis, karyolysis, and apoptosis) in rural adolescents, which indicates the ongoing negative impact of the closed Semipalatinsk Test Site and the salinization of the Aral Sea on the health of the younger generation of children.

Microbes used as a tool for bioremediation of heavy metal from the environment

Heavy metal pollution poses a serious threat to all forms of life in the environment due to the toxic effects of long-term environmental pollution. These metals are extremely sensitive at low concentrations and can be stored in food webs, posing a serious public health risk. Different organic pollutants and metals are not degradable and remain in their environment for a long time. Remediation using conventional physical and chemical methods is uneconomical and produces large volumes of chemical waste. The balance of hazardous metals has shown a strong and growing interest over the years. The use of biosensor microorganisms is eco-friendly and cost-effective. Therefore, microorganisms have a variety of mechanisms of metal sequestration that hold greater metal biosorption capacities. Finally, we provide suggestion from microbial tools to remove, recover metals, and metalloids from solutions using living or dead biomass and their components.

Extraction and Separation of Mn and Pb from Electrolytic Manganese Anodic Slime (EMAS) via SO2 Roasting Followed by Acid Leaching Process

Electrolytic manganese anodic slime (EMAS) with high contents of manganese and lead is a well-known refractory secondary resource because of its complex constituents and structure. Traditional stockpiling treatment of EMAS not only causes resource waste, but also leads to long-term environmental pollution. In this study, SO2 roasting followed by acid leaching process was put forward to extract and separate manganese and lead from the EMAS. Thermodynamic analysis showed that a coexistence area of MnSO4 and PbSO4 was present in both the roasting and leaching processes. During the roasting process, manganese and lead oxides were sulfated to MnSO4 and PbSO4 by SO2. Then, MnSO4 and PbSO4 could be separated in the following acid-leaching process owing to their different solubilities in acid solution. The leaching efficiencies of 92.5 wt.% for Mn and only 3.21 wt.% for Pb were obtained under optimal conditions. This study provides an alternative approach to utilize the EMAS.