Journal of Environmental Health Science and Engineering最新文献

Purpose

This study aimed to present an index (IEP) to evaluate the environmental performance of the sugar-energy industrial process based on the waste generated in manufacturing operations. The residues considered in this study were: vinasse, filter cake, ash and soot, residual waters, and sewage sludge.

Methods

The index created was developed to take into account, and to be directly proportional to the environmental impact of each residue generated by the sugar-energy production, to the relative spatial dispersion that each waste can reach, and to the environmental fragility of the hydrographic basin where the plant under evaluation is inserted and works. The lower IEP, the better the company valuation.

Results

The index was tested in a real company and exhibited an IEP Total = 1,4.10¹³ km².p/yr, which shows weak waste management by the enterprise. Vinasse was responsible for 50% of the IEP Total, while filter cake contributed 45% to it. Ash and soot, residual waters, and sewage sludge were together responsible for 5% of the IEP Total.

Conclusion

The theoretical conception used in this study is inspiring for the development of new studies on environmental assessment measurement. The study showed that vinasse is the most problematic waste in environmental terms, a conclusion that is in line with academic studies. Nevertheless, the waste with the greatest potential impact on the environment is filter cake. Despite this, filter cake presented a lower IEP(i) than vinasse, given that its negative impact on the basin is smaller. Both wastes contributed 95% of the IEP Total, which places them among the residues to be managed with greater attention.

Landfill leachate contains antibiotic resistance genes (ARGs) and microplastics (MPs), making it an important reservoir. However, little research has been conducted on how ARGs are enriched on MPs and how the presence of MPs affects pathogens and ARGs in leachates and soil. MPs possess the capacity to establish unique bacterial populations and assimilate contaminants from their immediate surroundings, generating a potential environment conducive to the growth of disease-causing microorganisms and antibiotic resistance genes (ARGs), thereby exerting selection pressure. Through a comprehensive analysis of scientific literature, we have carried out a practical assessment of this topic. The gathering of pollutants and the formation of dense bacterial communities on microplastics create advantageous circumstances for an increased frequency of ARG transfer and evolution. Additional investigations are necessary to acquire a more profound comprehension of how pathogens and ARGs are enriched, transported, and transferred on microplastics. This research is essential for evaluating the health risks associated with human exposure to these pollutants.

Graphical Abstract

This present study depicts the successful employment of fixed-bed column for total chromium removal from tannery wastewater in dynamic mode using sodium alginate-powdered marble beads (SA–Marble) as adsorbent. The SA–Marble composite beads prepared were characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS) and Brunauer, Emmett and Teller (BET) method. The adsorption process performance of this bio-sorbent was examined in batches and columns for real effluent (tannery wastewater). After 90 min, the total chromium removal efficiency could be kept above 90% in the batch experiment. The adsorption kinetics fit better with the pseudo-second-order model, indicating the chemisorption process and the adsorption capacity of about 67.74 mg g⁻¹ at 293 K (C0 = 7100 mg L⁻¹) was obtained. Additionally, dynamic experiments indicate that the total chromium removal efficiency could be maintained above 90% after 120 min at 293 K and 60 min at 318 and 333 K; it’s an endothermic but rapid process. The effects of two adsorption variables (Temperature and time) were investigated using central composite design (CCD), which is a subset of response surface methodology (total Cr, COD, sulfate, and total phosphorus percentage removal). This work paves a new avenue for synthesizing SA–Marble composite beads and provides an adsorption efficiency of total chromium removal from tannery wastewater.

Graphical abstract

Nowadays, public concern is focused on the degradation of water quality. For this reason, the development of innovative technologies for water treatment in view of (micro)pollutant removal is important. Indeed, organic (micro)pollutants, such as pharmaceuticals, herbicides, pesticides and plasticizers at concentration levels of μg L⁻¹ or even ng L⁻¹ are hardly removed during conventional wastewater treatment. In view of this, thermo-plasma expanded graphite, a light-weight innovative material in the form of a powder, was encapsulated into calcium alginate to obtain a granular form useful as filtration and adsorption material for removal of different pollutants. The produced material was used to remove atrazine, bisphenol-A, 17-α-ethinylestradiol and carbamazepine (at concentration levels of 125, 250 and 500 µg L⁻¹) by top-down filtration. The effect of flow rate, bed depth and adsorbent composition was evaluated based on breakthrough curves. The experimental data was analysed with the Adams-Bohart model in view of scale-up. Under optimal conditions, removal and adsorption capacity of respectively about 21%, 21%, 38%,42%, 43 µg g⁻¹, 44 µg g⁻¹, 37 µg g⁻¹ and 87 µg g⁻¹ were obtained for atrazine, bisphenol, 17-α ethinylestradiol and carbamazepine when using 0.12 g of thermo-plasma expanded graphite to treat 200 mL at 500 µg L⁻¹ (for each compound) of solution obtaining at contact time of 20 min. The granular form of TPEG obtained (GTPEG) by entrapping in calcium alginate results to have a good adsorbent property for the removal of carbamazepine, atrazine, bisphenol A and 17-α ethinylestradiol from water at concentration levels between 250 and 500 μg L⁻¹. Promising results confirm the adsorbent properties of TPEG and push-up us to investigate on its application and improve of its performance by evaluating different entrapping materials.

Purpose

Pollution of the environment with all kinds of plastics has become a growing problem. The problem of microplastics is mainly due to the absorption of stable organic pollutants and metals into them, and as a result, their environmental toxicity increases. The main purpose of this study is to investigate the appropriate and efficient methods of removing microplastics from aqueous environments through a systematic review.

Methods

Present study designed according to PRISMA guidelines. Two independent researchers followed all process from search to final analysis, for the relevant studies using international databases of PubMed, Scopus and ISI/WOS (Web of Science), without time limit. The search strategy developed based on the main axis of “microplastics”, “aqueous environments” and “removal”. This research was carried out from 2017 until the March of 2022. All relevant observational, analytical studies, review articles, and a meta-analysis were included.

Results

Through a comprehensive systematic search we found 2974 papers, after running the proses of refining, 80 eligible papers included to the study. According to the results of the review, the methods of removing microplastics from aquatic environments were divided to physical (12), chemical (18), physicochemical (27), biological (12) and integrated (11) methods. In different removal methods, the most dominant group of studied microplastics belonged to the four groups of polyethylene (PE), polystyrene (PS), polypropylene (PP) and polyethylene tetra phthalate (PET). Average removal efficiency of microplastics in different processes in each method was as: physical method (73.76%), chemical method (74.38%), physicochemical method (80.44%), biological method (75.23%) and integrated method (88.63%). The highest removal efficiency occurred in the processes based on the integrated method and the lowest efficiency occurred in the physical method. In total, 80% of the studies were conducted on a laboratory scale, 18.75% on a full scale and 1.25% on a pilot scale.

Conclusion

According to the findings; different processes based on physical, chemical, physicochemical, biological and integrated methods are able to remove microplastics with high efficiency from aqueous environments and in order to reduce their hazardous effects on health and environment, these processes can be easily used.

Potential of Arthrobacter citreus B27Pet, Bacillus thuringiensis B48Pet and Candida catnulata to produce biosurfactant using four different carbon sources (naphthalene, hexadecane, diesel and petroleum crude oil) was investigated. Removal of petroleum crude oil from aqueous culture and degradation of diesel were also determined using single and mixed culture of strains. The biofilm existence in single and mixed culture of strains was considered using naphthalene, hexadecane and diesel in culture medium. Cell surface hydrophobicity of A. citreus was higher than other isolates which also showed maximum surface tension reduction and emulsification index. As a whole, remarkable biosurfactant production occurred using petroleum crude oil as a carbon source in medium. A. citreus was found to be more robust than other tested strains in removal efficiency of crude oil due to its biosurfactant production capability. Statistically significant positive correlation was observed between biofilm existence and surface tension using diesel and hexadecane as carbon source. Overall diesel biodegradation efficiency by the mix culture of three applied strains was about 75% within a short period of time (10 days) which was accompanied with high biofilm production.

This research aims to assess the microbial electrolysis cell (MEC) fed with petroleum refinery wastewater (PRW) to produce power density and bio-electrochemical hydrogen. The MEC produces a maximum bio-electricity of 21.4 mA and a power density of 1200123.90 W/m² with a loading of chemical oxygen demand (COD) of 17000 mg/L. Due to catalyzed oxidation of complex compounds in PRW with a maintained microbial biofilm growth was observed after 90 d of operation of MEC. Results showed that the oxidation of organic substances in PRW enhanced the size in the growth of microbial film which further increased the generation of electrons leading to current density of 5890 mA/m². The COD removal efficiency of MEC was found to be 89.9%. The bio-electricity and hydrogen production of the MEC was estimated to be 24.5 mA and 19.2 L respectively when loaded with PRW having a COD of 17500 mg/L after 130 d. Present experiments demonstrate the efficiency of MEC technology efficiency in treating petroleum wastewater with the help of microbial biofilm.

Formaldehyde, a volatile organic compound (VOC), is one of the main gaseous pollutants from commercial cooking. The present study evaluated the effectiveness of a laboratory-scale ozone-assisted indirect plasma method for formaldehyde removal using response surface methodology (RSM). A dielectric barrier discharge (DBD) reactor was used for ozone generation. Inlet HCHO concentration, ozone concentration, and residence time were considered the design parameters, and formaldehyde removal efficiency (response 1) and energy yield (response 2) were considered response parameters. The optimized models showed a positive correlation between the predicted and experimental outcomes. Inlet ozone concentration, the most significant parameter in the removal efficiency model, represented a positive correlation with this response in most parts of the operating region. The optimal point with the highest desirability (i.e., D₁ point) was obtained at the inlet HCHO concentration of 120 ppm, inlet ozone concentration of 40 ppm, and reaction time of 11.35 s within the parameter ranges studied, resulting in 64% removal efficiency and 2.64 g/kWh energy yield. At the point with the second highest desirability (D₂), 100% removal efficiency along with 0.7 g/kWh energy yield was achieved indicating the very good performance of the process. The indirect plasma approach used in this study presented a successful performance in terms of removal efficiency along with acceptable energy yield compared to other plasma-assisted processes reported in the literature. The results suggested that ozone-assisted indirect plasma treatment can be utilized as an efficient alternative method for formaldehyde removal in commercial kitchens, while efficiency or energy yield should be prioritized for optimizing operating conditions.

This study focused on the potential for pentachlorophenol removal by a biological process in secondary treated wastewater (STWW). The proposed process is a combined method of phytoremediation using a native plant, Polypogon maritimus and Lemna minor, and bioaugmentation using a fungus. The bioaugmentation process was performed by a fungal isolate capable of removing PCP, isolated from the compost. The identification of the fungus was performed by morphological, biochemical, and molecular methods. A biological treatment system by bioaugmentation and phytoremediation was set up to estimate the capacity of this process to eliminate a high concentration of PCP. physico-chemical parameters, such as pH, COD, and BOD were tested at experimentation times T0 (initial) and Tf (final). The concentration of PCP is controlled by the HPLC method. Thus, the growth of the fungus was determined by spectrophotometry and enumeration on the agar medium. The results obtained show that the isolated and selected fungus is identified by Penicillium Ilerdanum. The fungal strain used has a significant capacity for tolerance and elimination of PCP. The results of the physico-chemical parameters showed an improvement in the quality of wastewater after the treatment was carried out. The elimination of PCP came with a release of Common law- and an important decrease in the DOC value in the STWW. The results obtained show that the Polypogon treatment shows a significant elimination of PCP by a percentage of the order of 92.01% and 23.58 g. L^− 1 chloride concentration. The macrophytes used showed a better ability to tolerate and eliminate PCP with an increase of chlorophyll and its longer sheets.

Abstract