Mehdi Ahmadmoazzam, A. Takdastan, A. Neisi, Mehdi Ahmadi, A. Babaei, S. Jorfi
Background: This study examined the removal of ciprofloxacin (CIP), which is a very widely used antibiotic, from an aqueous medium by applying AgI/Ag2 O photocatalyst under visible light radiation. Methods: AgI/Ag2 O was synthesized conveniently by applying a two-stage precipitation method. The synthesized compound was characterized by X-ray powder diffraction (XRD), FE- field emission scanning electron microscopy (FE-SEM), energy dispersive x-ray (EDX), and UV-Vis spectrophotometry. Different parameters including initial pH of the solution, initial CIP concentration, reaction kinetics, and catalyst reusability were investigated. Results: Concurrent use of AgI and Ag2 O caused improved photocatalytic properties in the presence of UV light. The pH and initial concentration of CIP affected the process efficiency; 95% efficiency was achieved within 100 min at pH 9. Furthermore, the process efficiency was still maintained over 90% after four consecutive cycles. Conclusion: The photocatalytic degradation process using AgI/Ag2 O nanocomposite under visible light radiation is a suitable method for removing CIP from aqueous media due to its high efficiency and stability.
{"title":"Photocatalytic removal of ciprofloxacin antibiotic from aqueous medium by applying AgI/Ag2 O nanocomposite: Activity test, reaction kinetics, and catalyst reusability","authors":"Mehdi Ahmadmoazzam, A. Takdastan, A. Neisi, Mehdi Ahmadi, A. Babaei, S. Jorfi","doi":"10.34172/ehem.2022.32","DOIUrl":"https://doi.org/10.34172/ehem.2022.32","url":null,"abstract":"Background: This study examined the removal of ciprofloxacin (CIP), which is a very widely used antibiotic, from an aqueous medium by applying AgI/Ag2 O photocatalyst under visible light radiation. Methods: AgI/Ag2 O was synthesized conveniently by applying a two-stage precipitation method. The synthesized compound was characterized by X-ray powder diffraction (XRD), FE- field emission scanning electron microscopy (FE-SEM), energy dispersive x-ray (EDX), and UV-Vis spectrophotometry. Different parameters including initial pH of the solution, initial CIP concentration, reaction kinetics, and catalyst reusability were investigated. Results: Concurrent use of AgI and Ag2 O caused improved photocatalytic properties in the presence of UV light. The pH and initial concentration of CIP affected the process efficiency; 95% efficiency was achieved within 100 min at pH 9. Furthermore, the process efficiency was still maintained over 90% after four consecutive cycles. Conclusion: The photocatalytic degradation process using AgI/Ag2 O nanocomposite under visible light radiation is a suitable method for removing CIP from aqueous media due to its high efficiency and stability.","PeriodicalId":51877,"journal":{"name":"Environmental Health Engineering and Management Journal","volume":null,"pages":null},"PeriodicalIF":1.6,"publicationDate":"2022-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45601252","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
F. Gholami-Borujeni, H. Rahimi, Seyed Mehdi Sajjadi
Background: Helicobacter pylori is classified as a carcinogen, and it is also the most common cause of chronic bacterial infection and peptic ulcers. Approximately 45% of people are infected with the bacterium. Methods: In this study, the H. pylori genes, CagA and VacA, were investigated in drinking water, using 100 samples (50 samples from the municipal water supply and 50 samples from the effluent of household water treatment devices). DNA was extracted from colonies with a positive heterotrophic plate count (HPC) for use in molecular testing and microbial identification. The polymerase chain reaction (PCR) was used to identify H. pylori. Results: The study showed that 24% of urban water samples (12% above the World Health Organization [WHO] standards for safe drinking water) and 18% of home water treatment-device samples (4% above the WHO standards) were HPC-positive. The H. pylori genes, CagA and VacA, were identified in 2% of the samples from household water treatment devices and 8% of the municipal water supply samples. Conclusion: The study findings show that H. pylori may be transmitted in drinking water. However, there is currently no strong evidence that the bacteria can survive after the disinfection process in the water supply system. Therefore, the health risks of this bacterium in drinking water are still unknown.
{"title":"Detection of Helicobacter pylori genes (CagA and VacA) in municipal drinking water","authors":"F. Gholami-Borujeni, H. Rahimi, Seyed Mehdi Sajjadi","doi":"10.34172/ehem.2022.31","DOIUrl":"https://doi.org/10.34172/ehem.2022.31","url":null,"abstract":"Background: Helicobacter pylori is classified as a carcinogen, and it is also the most common cause of chronic bacterial infection and peptic ulcers. Approximately 45% of people are infected with the bacterium. Methods: In this study, the H. pylori genes, CagA and VacA, were investigated in drinking water, using 100 samples (50 samples from the municipal water supply and 50 samples from the effluent of household water treatment devices). DNA was extracted from colonies with a positive heterotrophic plate count (HPC) for use in molecular testing and microbial identification. The polymerase chain reaction (PCR) was used to identify H. pylori. Results: The study showed that 24% of urban water samples (12% above the World Health Organization [WHO] standards for safe drinking water) and 18% of home water treatment-device samples (4% above the WHO standards) were HPC-positive. The H. pylori genes, CagA and VacA, were identified in 2% of the samples from household water treatment devices and 8% of the municipal water supply samples. Conclusion: The study findings show that H. pylori may be transmitted in drinking water. However, there is currently no strong evidence that the bacteria can survive after the disinfection process in the water supply system. Therefore, the health risks of this bacterium in drinking water are still unknown.","PeriodicalId":51877,"journal":{"name":"Environmental Health Engineering and Management Journal","volume":null,"pages":null},"PeriodicalIF":1.6,"publicationDate":"2022-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49069031","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Idoko Apeh Abraham, Igboro Bamedele Sunday, S. B. Saulawa, Chukwuemeka Eneogwe
Background: Spatial noise level mapping using a geographical information system (GIS) is essential for the visual colour representation of noise analysis, which is a necessity for strategic planning and mitigating measures. Methods: Extech noise meter (model 407750) was used for sound measurement and a GIS (inverse distance weighted) was used in 54 study locations for the spatial interpolation. The study was classified into five categories based on Nigeria’s WHO standard and National Environmental Standards and Regulations Enforcement Agency (NESREA). Results: For the LDAY (D),LEvening (E), LNight (N), and LDEN, all the locations exceeded the WHO standard while 94.4%, 90.7%, 83.3%, and 83.3% of the locations exceeded the NESREA standard. The LDay (D) ranged from the minimum value of 67.6 dB (A) at the Ijaw residential area to the maximum value of 93.0 dB (A) at Kwangila site (1) intersection. The LNight ranged from the minimum value of 63.3 dB (A) at Dogorawa residential area to the maximum value of 92.1 dB (A) at Kwangila site (1). The LDEN ranged from the minimum value of 73.1 dB (A) at Hanwa residential areas to the maximum value of 97.2 dB (A) at Kwangila site (1). The noise quality rating ranged from satisfactory to unallowed noise quality grading. The selected intersections and residential areas with light commercial activities had the highest and lowest noise levels, respectively. Conclusion: Efficient maintenance of silencers, planting trees with dense foliage, and strategic planning would be necessary panacea in curbing excessive noise.
{"title":"Evaluation and spatial noise mapping using geographical information system (GIS): A case study in Zaria city, Kaduna State, Nigeria","authors":"Idoko Apeh Abraham, Igboro Bamedele Sunday, S. B. Saulawa, Chukwuemeka Eneogwe","doi":"10.34172/ehem.2022.24","DOIUrl":"https://doi.org/10.34172/ehem.2022.24","url":null,"abstract":"Background: Spatial noise level mapping using a geographical information system (GIS) is essential for the visual colour representation of noise analysis, which is a necessity for strategic planning and mitigating measures. Methods: Extech noise meter (model 407750) was used for sound measurement and a GIS (inverse distance weighted) was used in 54 study locations for the spatial interpolation. The study was classified into five categories based on Nigeria’s WHO standard and National Environmental Standards and Regulations Enforcement Agency (NESREA). Results: For the LDAY (D),LEvening (E), LNight (N), and LDEN, all the locations exceeded the WHO standard while 94.4%, 90.7%, 83.3%, and 83.3% of the locations exceeded the NESREA standard. The LDay (D) ranged from the minimum value of 67.6 dB (A) at the Ijaw residential area to the maximum value of 93.0 dB (A) at Kwangila site (1) intersection. The LNight ranged from the minimum value of 63.3 dB (A) at Dogorawa residential area to the maximum value of 92.1 dB (A) at Kwangila site (1). The LDEN ranged from the minimum value of 73.1 dB (A) at Hanwa residential areas to the maximum value of 97.2 dB (A) at Kwangila site (1). The noise quality rating ranged from satisfactory to unallowed noise quality grading. The selected intersections and residential areas with light commercial activities had the highest and lowest noise levels, respectively. Conclusion: Efficient maintenance of silencers, planting trees with dense foliage, and strategic planning would be necessary panacea in curbing excessive noise.","PeriodicalId":51877,"journal":{"name":"Environmental Health Engineering and Management Journal","volume":null,"pages":null},"PeriodicalIF":1.6,"publicationDate":"2022-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44250607","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Mehri Samandari, H. Movahedian Attar, K. Ebrahimpour, F. Mohammadi, Soudabeh Ghodsi
Background: In recent years, the world has faced with the COVID-19 pandemic, followed by a significant increase in the use of antibiotics to control the COVID-19 and other secondary infections. The nonbiodegradable characteristics of antibiotics and their residues in the environment leads to increased microbial and drug resistance. Therefore, due to the high importance of antibiotics, two antibiotics, ampicillin and penicillin G, were studied in Isfahan municipal wastewater treatment plants (WWTPs). Methods: Sampling was performed for two months during 13 sampling periods and antibiotics were measured using high-performance liquid chromatography with UV detector (HPLC/UV) instrument. Results: Ampicillin and penicillin G were identified in all samples taken from the both WWTPs. The average concentration of penicillin G in WWTP E and S at the influent, effluent and its removal efficiency were 1050.54±761.43 µg/L, 52.89±49.27 µg/L, 89.80±19.42%, 2055.12±1788.08 µg/L, 143.01±162.59 µg/L and 82.76±21.85%, respectively. Also, the average concentration of ampicillin in WWTP E and S in the influent (796.44±809.6 and 447.1±322.39 µg/L), effluent (48.94±24.25 and 90.31±75.91 µg/L), and its removal efficiency (86.22±19.84% and 66.85±24.88%) were determined. Conclusion: In two studied WWTPs, the concentration of antibiotics was higher during the COVID-19 pandemic in comparison with previous studies. The statistical analysis showed that there was no significant relationship between the concentration of antibiotics in WWTPs (P<0.05). Also, the statistical results indicated that the correlation is not significant between removal efficiency of antibiotics and removal efficiency of wastewater main parameters.
{"title":"Measurement of ampicillin and penicillin G antibiotics in wastewater treatment plants during the COVID-19 pandemic: A case study in Isfahan","authors":"Mehri Samandari, H. Movahedian Attar, K. Ebrahimpour, F. Mohammadi, Soudabeh Ghodsi","doi":"10.34172/ehem.2022.21","DOIUrl":"https://doi.org/10.34172/ehem.2022.21","url":null,"abstract":"Background: In recent years, the world has faced with the COVID-19 pandemic, followed by a significant increase in the use of antibiotics to control the COVID-19 and other secondary infections. The nonbiodegradable characteristics of antibiotics and their residues in the environment leads to increased microbial and drug resistance. Therefore, due to the high importance of antibiotics, two antibiotics, ampicillin and penicillin G, were studied in Isfahan municipal wastewater treatment plants (WWTPs). Methods: Sampling was performed for two months during 13 sampling periods and antibiotics were measured using high-performance liquid chromatography with UV detector (HPLC/UV) instrument. Results: Ampicillin and penicillin G were identified in all samples taken from the both WWTPs. The average concentration of penicillin G in WWTP E and S at the influent, effluent and its removal efficiency were 1050.54±761.43 µg/L, 52.89±49.27 µg/L, 89.80±19.42%, 2055.12±1788.08 µg/L, 143.01±162.59 µg/L and 82.76±21.85%, respectively. Also, the average concentration of ampicillin in WWTP E and S in the influent (796.44±809.6 and 447.1±322.39 µg/L), effluent (48.94±24.25 and 90.31±75.91 µg/L), and its removal efficiency (86.22±19.84% and 66.85±24.88%) were determined. Conclusion: In two studied WWTPs, the concentration of antibiotics was higher during the COVID-19 pandemic in comparison with previous studies. The statistical analysis showed that there was no significant relationship between the concentration of antibiotics in WWTPs (P<0.05). Also, the statistical results indicated that the correlation is not significant between removal efficiency of antibiotics and removal efficiency of wastewater main parameters.","PeriodicalId":51877,"journal":{"name":"Environmental Health Engineering and Management Journal","volume":null,"pages":null},"PeriodicalIF":1.6,"publicationDate":"2022-08-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47795942","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Background: As concentrations of heavy metals in hair can reflect both metals exposure and intake concentrations, hair sample analysis is widely applied in forensic sciences, evaluation of environmental or occupational exposure and other studies. The aim of this study was to evaluate the concentrations of As, Cd, Pb, Cr, Cu, Co, Mn, Zn, Fe and Ni in the scalp hair of an urban population from Kermanshah in western Iran. Methods: In the present research, 30 points of the city were selected for human scalp hair sampling. Samples were taken from healthy inhabitants (aged 6 to 46 years) in Kermanshah city. Multivariate analysis method was applied to distinguish the anthropogenic and natural sources of heavy metals. Levels of elements in the scalp hair were measured by ICP-MS. Results: The mean concentrations of Cr, Mn, Fe, Co, Ni, Cu, Zn, Cd, Pb and As were 33.53±9.05, 27.98±7.77, 203.18±22.31, 1.94±0.85, 18.44±3.40, 107.11±22.56, 119.21±10.52, 0.97±0.36, 60.27±13.84, and 0.34±0.51 µg/g in the urban area, respectively. The highest concentration of all elements was found in the age group of 31-40 and 41-50 years except Fe, the maximum concentration of which was found in the age group of 6-20 years. Significant differences were found between smokers and non-smokers. Conclusion: Comparison of the heavy metals concentrations in the scalp hair of this area showed that the concentrations of the elements were clearly higher than those reported in other studies. However, the high concentrations of the elements in hair indicated that the inhabitants in the urban areas of Kermanshah might be at risk of exposure to high levels of toxic elements.
{"title":"Arsenic and heavy metal concentrations in human hair from urban areas","authors":"E. Solgi, Selahedin Mahmoudi","doi":"10.34172/ehem.2022.25","DOIUrl":"https://doi.org/10.34172/ehem.2022.25","url":null,"abstract":"Background: As concentrations of heavy metals in hair can reflect both metals exposure and intake concentrations, hair sample analysis is widely applied in forensic sciences, evaluation of environmental or occupational exposure and other studies. The aim of this study was to evaluate the concentrations of As, Cd, Pb, Cr, Cu, Co, Mn, Zn, Fe and Ni in the scalp hair of an urban population from Kermanshah in western Iran. Methods: In the present research, 30 points of the city were selected for human scalp hair sampling. Samples were taken from healthy inhabitants (aged 6 to 46 years) in Kermanshah city. Multivariate analysis method was applied to distinguish the anthropogenic and natural sources of heavy metals. Levels of elements in the scalp hair were measured by ICP-MS. Results: The mean concentrations of Cr, Mn, Fe, Co, Ni, Cu, Zn, Cd, Pb and As were 33.53±9.05, 27.98±7.77, 203.18±22.31, 1.94±0.85, 18.44±3.40, 107.11±22.56, 119.21±10.52, 0.97±0.36, 60.27±13.84, and 0.34±0.51 µg/g in the urban area, respectively. The highest concentration of all elements was found in the age group of 31-40 and 41-50 years except Fe, the maximum concentration of which was found in the age group of 6-20 years. Significant differences were found between smokers and non-smokers. Conclusion: Comparison of the heavy metals concentrations in the scalp hair of this area showed that the concentrations of the elements were clearly higher than those reported in other studies. However, the high concentrations of the elements in hair indicated that the inhabitants in the urban areas of Kermanshah might be at risk of exposure to high levels of toxic elements.","PeriodicalId":51877,"journal":{"name":"Environmental Health Engineering and Management Journal","volume":null,"pages":null},"PeriodicalIF":1.6,"publicationDate":"2022-08-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44173299","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"The need for careful monitoring and control of medical travels during COVID-19: A letter to the editor","authors":"Mousa Bamir, Atousa Poursheikhali, A. Masoud","doi":"10.34172/EHEM.2022.33","DOIUrl":"https://doi.org/10.34172/EHEM.2022.33","url":null,"abstract":"","PeriodicalId":51877,"journal":{"name":"Environmental Health Engineering and Management Journal","volume":null,"pages":null},"PeriodicalIF":1.6,"publicationDate":"2022-08-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46510100","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Ali Haghmoradkhani, A. Pardakhti, Mohammad Ali Zahed
Background: Adsorption is a process in which some of the components in the fluid phase, are selectively transferred to the surface of the porous solid particles in the filled bed, which is called the adsorbent. The aim of this study was to examine the adsorption effectiveness of CO2 by activated carbon functionalized with methyl diethanolamine (MDEA), as well as the effects of adsorption temperature, the total pressure of adsorption, and mass of adsorbent. Methods: Activated carbon was first produced using the desired biomasses and suitable activated carbon was chosen. The activated carbon was then functionalized with MDEA amination method. The crystal structure of adsorbents was studied using X-ray diffraction (XRD) methods. In addition, the porosity, specific surface area and structure of prepared activated carbon were measured using BET techniques. Finally, the morphology and strength of the functional groups were measured using Field emission scanning electron microscopy (FESEM) and Fourier-transform infrared spectroscopy (FTIR) analyses. Results: The findings of the FESEM and BET analyses for functionalized activated carbon revealed that the specific surface area of the adsorbent increased throughout the chemical and physical modification process, resulting in a BET amount of 725/84 m2 /g. The results showed that the selectivity of the functionalized activated carbon is greater than that of the non-functionalized adsorbent. Conclusion: The adsorption capacity of functionalized activated carbon was 3.98 mmol CO2 g-1 sorbent, compared to 2.587 mmol CO2 g-1 sorbent in the non-functionalized carbon, indicating a 35% improvement in the efficiency of the functionalized sample. According to the findings of the desorption experiments, functionalized carbon shows a 25% decrease in CO2 adsorption efficiency after 20 desorption steps.
背景:吸附是一种过程，其中一些组分的流体相，被选择性地转移到表面的多孔固体颗粒在填充床，这是称为吸附剂。研究了甲基二乙醇胺(MDEA)功能化活性炭对CO2的吸附效果，以及吸附温度、吸附总压和吸附剂质量对其吸附效果的影响。方法:首先以所需的生物质为原料制备活性炭，选择合适的活性炭。然后用MDEA胺化法对活性炭进行功能化。采用x射线衍射(XRD)方法研究了吸附剂的晶体结构。此外，用BET技术测定了制备的活性炭的孔隙率、比表面积和结构。最后，利用场发射扫描电镜(FESEM)和傅里叶变换红外光谱(FTIR)分析测量了官能团的形态和强度。结果:功能化活性炭的FESEM和BET分析结果表明，在化学和物理改性过程中，吸附剂的比表面积增加，BET量为725/84 m2 /g。结果表明，功能化活性炭的选择性大于非功能化吸附剂。结论:功能化活性炭的吸附剂吸附量为3.98 mmol CO2 g-1，而非功能化活性炭的吸附剂吸附量为2.587 mmol CO2 g-1，表明功能化样品的效率提高了35%。解吸实验结果表明，经过20步解吸后，官能化碳的CO2吸附效率降低了25%。
{"title":"Evaluation of adsorption efficiency of activated carbon functionalized with methyl diethanolamine in carbon dioxide gas","authors":"Ali Haghmoradkhani, A. Pardakhti, Mohammad Ali Zahed","doi":"10.34172/ehem.2022.27","DOIUrl":"https://doi.org/10.34172/ehem.2022.27","url":null,"abstract":"Background: Adsorption is a process in which some of the components in the fluid phase, are selectively transferred to the surface of the porous solid particles in the filled bed, which is called the adsorbent. The aim of this study was to examine the adsorption effectiveness of CO2 by activated carbon functionalized with methyl diethanolamine (MDEA), as well as the effects of adsorption temperature, the total pressure of adsorption, and mass of adsorbent. Methods: Activated carbon was first produced using the desired biomasses and suitable activated carbon was chosen. The activated carbon was then functionalized with MDEA amination method. The crystal structure of adsorbents was studied using X-ray diffraction (XRD) methods. In addition, the porosity, specific surface area and structure of prepared activated carbon were measured using BET techniques. Finally, the morphology and strength of the functional groups were measured using Field emission scanning electron microscopy (FESEM) and Fourier-transform infrared spectroscopy (FTIR) analyses. Results: The findings of the FESEM and BET analyses for functionalized activated carbon revealed that the specific surface area of the adsorbent increased throughout the chemical and physical modification process, resulting in a BET amount of 725/84 m2 /g. The results showed that the selectivity of the functionalized activated carbon is greater than that of the non-functionalized adsorbent. Conclusion: The adsorption capacity of functionalized activated carbon was 3.98 mmol CO2 g-1 sorbent, compared to 2.587 mmol CO2 g-1 sorbent in the non-functionalized carbon, indicating a 35% improvement in the efficiency of the functionalized sample. According to the findings of the desorption experiments, functionalized carbon shows a 25% decrease in CO2 adsorption efficiency after 20 desorption steps.","PeriodicalId":51877,"journal":{"name":"Environmental Health Engineering and Management Journal","volume":null,"pages":null},"PeriodicalIF":1.6,"publicationDate":"2022-08-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46582197","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Background: To control pollution, wastewater treatment from textile plays an important role in treating wastewater to meet quality standards before it is discharged into the environment. Without properly treated wastewater from the textile industry, it contains organic and inorganic pollutants that cause environmental problems such as water pollution, loss of marine life, and soil and air pollution. The aim of this study was to design and simulate a textile sewage treatment plant. Methods: This study was conducted by simulating the process and operation of a wastewater treatment plant using STOAT software. In addition, STOAT’s graphical and static data analysis models are efficient in removing multi-component pollutants from the textile industry. Results: Some pollutant parameters prior to the design model are suspended solids (SS) (260 mg/L), DS (3600 mg/L), ammonia (65 mg/L), biochemical oxygen demand (BOD) (430 mg/L), nitrate (35 mg/L), and dissolved Oxygen (DO) (12 mg/L). The wastewater of the simulation result of the sewage treatment plant model contained SS (3.3 mg/L), ammonia (25 mg/L), BOD (4 mg/L), nitrate (61.3 mg/L), and the removal percentage of total suspended solids (TSS), BOD, and Ammonia was 99.75, 99.1, 61.33 mg/L, respectively. Through the treatment process, Ammonia was oxidized and nitrification was processed rather than denitrification. Conclusion: Using the stoat modeling software, wastewater treatment plant design is very effective in removing contaminants from textile wastewater by selecting specific parameters.
{"title":"Performance improvement of textile wastewater treatment plant design by STOAT model simulation","authors":"D. A. Akuma, Ketema Beyecha Hundie, T. Bullo","doi":"10.34172/ehem.2022.22","DOIUrl":"https://doi.org/10.34172/ehem.2022.22","url":null,"abstract":"Background: To control pollution, wastewater treatment from textile plays an important role in treating wastewater to meet quality standards before it is discharged into the environment. Without properly treated wastewater from the textile industry, it contains organic and inorganic pollutants that cause environmental problems such as water pollution, loss of marine life, and soil and air pollution. The aim of this study was to design and simulate a textile sewage treatment plant. Methods: This study was conducted by simulating the process and operation of a wastewater treatment plant using STOAT software. In addition, STOAT’s graphical and static data analysis models are efficient in removing multi-component pollutants from the textile industry. Results: Some pollutant parameters prior to the design model are suspended solids (SS) (260 mg/L), DS (3600 mg/L), ammonia (65 mg/L), biochemical oxygen demand (BOD) (430 mg/L), nitrate (35 mg/L), and dissolved Oxygen (DO) (12 mg/L). The wastewater of the simulation result of the sewage treatment plant model contained SS (3.3 mg/L), ammonia (25 mg/L), BOD (4 mg/L), nitrate (61.3 mg/L), and the removal percentage of total suspended solids (TSS), BOD, and Ammonia was 99.75, 99.1, 61.33 mg/L, respectively. Through the treatment process, Ammonia was oxidized and nitrification was processed rather than denitrification. Conclusion: Using the stoat modeling software, wastewater treatment plant design is very effective in removing contaminants from textile wastewater by selecting specific parameters.","PeriodicalId":51877,"journal":{"name":"Environmental Health Engineering and Management Journal","volume":null,"pages":null},"PeriodicalIF":1.6,"publicationDate":"2022-08-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48897906","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A. Jakada, Suraya Mahmood, Ali Umar Ahmad, Ibrahim Garba Muhammad, Ismail Aliyu Danmaraya, N. Yahaya
Background: The need to understand the causes of CO2 emissions has prompted the formulation of strategies to prevent global warming. Therefore, the purpose of the study was to determine the input variable that is the most influential in contributing to CO2 emissions and at the same time to forecast the effect of a shock in macroeconomic variables on CO2 emissions for 6 leading African countries over the period of 1970 to 2019. Methods: In this study, the statistical methods of impulse response function and variance decomposition techniques of analysis were used. Results: A one-standard-deviation rise in economic growth leads to an increase in CO2 emissions. A shifts in the square of economic growth increased CO2 emissions, the shock was smaller than that of economic growth. This confirms the theory of environmental Kuznets curve (EKC) in Africa. A shocks to FDI had a positive influence on CO2 emissions. A one standard deviation shock in financial development had an instantaneous positive impact on CO2 emissions. FDI had a greater effect than other factors in explaining CO2 emissions over the short and medium term. In the long run, economic growth contributes the most to CO2 emissions among the explanatory variables. Conclusion: The findings of the study can be used as a reference for international organizations and environmental policymakers in forecasting climate change and assisting in policy decision-making. Africa must boost economic growth through industrial, agricultural, and energy usage patterns and integrate innovation, research, and technology advances into their developmental agenda to fulfil sustainable development goals while lowering CO2 emissions and their consequences.
{"title":"Driving forces of CO2 Emissions based on impulse response function and variance decomposition: A case of the main African countries","authors":"A. Jakada, Suraya Mahmood, Ali Umar Ahmad, Ibrahim Garba Muhammad, Ismail Aliyu Danmaraya, N. Yahaya","doi":"10.34172/ehem.2022.23","DOIUrl":"https://doi.org/10.34172/ehem.2022.23","url":null,"abstract":"Background: The need to understand the causes of CO2 emissions has prompted the formulation of strategies to prevent global warming. Therefore, the purpose of the study was to determine the input variable that is the most influential in contributing to CO2 emissions and at the same time to forecast the effect of a shock in macroeconomic variables on CO2 emissions for 6 leading African countries over the period of 1970 to 2019. Methods: In this study, the statistical methods of impulse response function and variance decomposition techniques of analysis were used. Results: A one-standard-deviation rise in economic growth leads to an increase in CO2 emissions. A shifts in the square of economic growth increased CO2 emissions, the shock was smaller than that of economic growth. This confirms the theory of environmental Kuznets curve (EKC) in Africa. A shocks to FDI had a positive influence on CO2 emissions. A one standard deviation shock in financial development had an instantaneous positive impact on CO2 emissions. FDI had a greater effect than other factors in explaining CO2 emissions over the short and medium term. In the long run, economic growth contributes the most to CO2 emissions among the explanatory variables. Conclusion: The findings of the study can be used as a reference for international organizations and environmental policymakers in forecasting climate change and assisting in policy decision-making. Africa must boost economic growth through industrial, agricultural, and energy usage patterns and integrate innovation, research, and technology advances into their developmental agenda to fulfil sustainable development goals while lowering CO2 emissions and their consequences.","PeriodicalId":51877,"journal":{"name":"Environmental Health Engineering and Management Journal","volume":null,"pages":null},"PeriodicalIF":1.6,"publicationDate":"2022-07-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43584245","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Neematollah Jaafarzadeh Haghighi Fard, S. Jorfi, M. Panahi Fard, Maneli Ardashir Zadeh
Background: The emergence and spread of SARS-CoV-2 has increased environmental disinfectant usage to reduce the transmission of this virus. Ethanol 70%-90% and 5% sodium hypochlorite have the highest consumption for disinfection of various environmental surfaces during the COVID-19 pandemic. Dental unit waterlines (DUWLs) are more susceptible to microbial contamination due to their particular structure. This study aimed to investigate the effect of increasing the use of disinfectants during the COVID-19 pandemic on the bacterial contamination of DUWLs. Methods: During November (before the COVID-19 pandemic) and December (during the COVID-19 pandemic), a questionnaire was used to assess the frequency of disinfection of unit surfaces and other environmental surfaces and the type of disinfectants used. The water samples were collected from different parts of DUWLs. The gram staining method followed by the biochemical method was used to identify the desired bacteria. Results: The results showed that the frequency of disinfection of dental units increased 8 times in December compared to November. There is a significant inverse relationship between the frequency of disinfection of dental units surfaces and the bacterial contamination of DUWLs. Conclusion: The microbial load in different parts of the DUWLs was less than 200 CFU/mL. The American Dental Association (ADA) recommended and indicated the allowable microbial concentration and the appropriate quality and water used in these units.
{"title":"The effect of the use of disinfectants during COVID-19 pandemic on the bacterial contamination of dental unit waterlines","authors":"Neematollah Jaafarzadeh Haghighi Fard, S. Jorfi, M. Panahi Fard, Maneli Ardashir Zadeh","doi":"10.34172/ehem.2022.26","DOIUrl":"https://doi.org/10.34172/ehem.2022.26","url":null,"abstract":"Background: The emergence and spread of SARS-CoV-2 has increased environmental disinfectant usage to reduce the transmission of this virus. Ethanol 70%-90% and 5% sodium hypochlorite have the highest consumption for disinfection of various environmental surfaces during the COVID-19 pandemic. Dental unit waterlines (DUWLs) are more susceptible to microbial contamination due to their particular structure. This study aimed to investigate the effect of increasing the use of disinfectants during the COVID-19 pandemic on the bacterial contamination of DUWLs. Methods: During November (before the COVID-19 pandemic) and December (during the COVID-19 pandemic), a questionnaire was used to assess the frequency of disinfection of unit surfaces and other environmental surfaces and the type of disinfectants used. The water samples were collected from different parts of DUWLs. The gram staining method followed by the biochemical method was used to identify the desired bacteria. Results: The results showed that the frequency of disinfection of dental units increased 8 times in December compared to November. There is a significant inverse relationship between the frequency of disinfection of dental units surfaces and the bacterial contamination of DUWLs. Conclusion: The microbial load in different parts of the DUWLs was less than 200 CFU/mL. The American Dental Association (ADA) recommended and indicated the allowable microbial concentration and the appropriate quality and water used in these units.","PeriodicalId":51877,"journal":{"name":"Environmental Health Engineering and Management Journal","volume":null,"pages":null},"PeriodicalIF":1.6,"publicationDate":"2022-07-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44201533","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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