Mohamed Ali Ahmed, M. Mohamed, Mst. Mahmuda Parvin, P. Ilić
{"title":"The Recurrence of Natural Disasters in Jowhar, Middle Shabelle Region, Somalia: The Causes and Impacts","authors":"Mohamed Ali Ahmed, M. Mohamed, Mst. Mahmuda Parvin, P. Ilić","doi":"10.4236/jep.2022.139042","DOIUrl":"https://doi.org/10.4236/jep.2022.139042","url":null,"abstract":"","PeriodicalId":59176,"journal":{"name":"环境保护(英文)","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70318157","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":"Estimation and Impact Factor of Pathogens in the Lijiang River Using Water Quality Modeling","authors":"Jenny Zhang, D. Yuan","doi":"10.4236/jep.2022.137033","DOIUrl":"https://doi.org/10.4236/jep.2022.137033","url":null,"abstract":"","PeriodicalId":59176,"journal":{"name":"环境保护(英文)","volume":"58 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70318351","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}
Pub Date : 2021-10-14DOI: 10.4236/jep.2021.1210041
Lumami Kapepula Vercus, T. Ndikumana, N. E. Tamungang, Musibono Eyul’Anki Dieudonné, Lukusa Mbaya Alain, Nsimanda Ipey Camille, P. L. Alconero, B. Bruggen
This study focuses on determining the toxicological risks of urban waste from the city of Uvira, discharged into Lake Tanganyika, on the surrounding population. Volatile organic compounds were measured in a variety of solid waste matrices, including inorganic micropollutants in wastewater and fish. The concentrations of Hg and Pb in the lake were found to be 1.21 and 1.42 μg/L respectively and between 0.83 to 18.36 μg/L of Hg and 8.25 to 670 μg/L of Pb, at the collector outlet. The presence of trace metallic elements, such as Cr, Co, Ni, Cu, Zn, As, Sb, Hg and Pb, were detected at high concentrations compared to the WHO standard. An ecotoxicology experiment herein on wastewater samples showed lethal pollutant concentrations of the order of 0.0055 mL/mL which killed at least 50% of fish (LC50), confirming the toxicity of the wastewater. These potentially harmful effluents also contain volatile organic compounds originating in high concentration from the pharmaceutical discharges of the general Uvira hospital, in particular: toluene, ethylbenzene, m-xylene/p-xylene, o-xylene and chloroform in higher concentrations compared to the norm. Other components such as benzene, bromodichloroethane and 1,1-dichloroethane were found to be present, but at a concentration below 0.05 ppb. A variety of trace organics can be suspected to be present as well.
{"title":"Determination of the Toxicological Risk of Urban Waste from the City of Uvira Dumped into the North-Western Coast in Lake Tanganyika (Democratic Republic of Congo)","authors":"Lumami Kapepula Vercus, T. Ndikumana, N. E. Tamungang, Musibono Eyul’Anki Dieudonné, Lukusa Mbaya Alain, Nsimanda Ipey Camille, P. L. Alconero, B. Bruggen","doi":"10.4236/jep.2021.1210041","DOIUrl":"https://doi.org/10.4236/jep.2021.1210041","url":null,"abstract":"This study focuses on determining the toxicological risks of urban waste from the city of Uvira, discharged into Lake Tanganyika, on the surrounding population. Volatile organic compounds were measured in a variety of solid waste matrices, including inorganic micropollutants in wastewater and fish. The concentrations of Hg and Pb in the lake were found to be 1.21 and 1.42 μg/L respectively and between 0.83 to 18.36 μg/L of Hg and 8.25 to 670 μg/L of Pb, at the collector outlet. The presence of trace metallic elements, such as Cr, Co, Ni, Cu, Zn, As, Sb, Hg and Pb, were detected at high concentrations compared to the WHO standard. An ecotoxicology experiment herein on wastewater samples showed lethal pollutant concentrations of the order of 0.0055 mL/mL which killed at least 50% of fish (LC50), confirming the toxicity of the wastewater. These potentially harmful effluents also contain volatile organic compounds originating in high concentration from the pharmaceutical discharges of the general Uvira hospital, in particular: toluene, ethylbenzene, m-xylene/p-xylene, o-xylene and chloroform in higher concentrations compared to the norm. Other components such as benzene, bromodichloroethane and 1,1-dichloroethane were found to be present, but at a concentration below 0.05 ppb. A variety of trace organics can be suspected to be present as well.","PeriodicalId":59176,"journal":{"name":"环境保护(英文)","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48143016","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}
The nitrogen cycle is the basis for understanding nitrogen dynamics in soil fertility and ecosystem health. Nitrification and denitrification are key nitrogen cycle components that influence nitrogen uptake in food crops, thus critical to food security. Rice (Oryza sativa) is comparatively unique in that the nitrification-denitrification sequence is a perceived loss of available nitrogen for plant uptake and the production of nitrous oxide (N2O) has severe implications in climate change. This review focuses on recent research involving nitrification and denitrification, with an emphasis on rice. The review also focuses on the emerging irrigation strategies associated with furrow irrigation and alternating wetting-drying irrigation. With growing global interest in reducing irrigation water application, new research paradigms are emerging to perfect these reduced water applications systems to guarantee food security and farm profitability.
{"title":"Nitrification and Denitrification Processes in Rice (Oryza Sativa), with an Emphasis on Reduced Water Irrigation Regimes in USA","authors":"M. Aide","doi":"10.4236/jep.2021.129036","DOIUrl":"https://doi.org/10.4236/jep.2021.129036","url":null,"abstract":"The nitrogen cycle is the basis for understanding nitrogen dynamics in soil fertility and ecosystem health. Nitrification and denitrification are key nitrogen cycle components that influence nitrogen uptake in food crops, thus critical to food security. Rice (Oryza sativa) is comparatively unique in that the nitrification-denitrification sequence is a perceived loss of available nitrogen for plant uptake and the production of nitrous oxide (N2O) has severe implications in climate change. This review focuses on recent research involving nitrification and denitrification, with an emphasis on rice. The review also focuses on the emerging irrigation strategies associated with furrow irrigation and alternating wetting-drying irrigation. With growing global interest in reducing irrigation water application, new research paradigms are emerging to perfect these reduced water applications systems to guarantee food security and farm profitability.","PeriodicalId":59176,"journal":{"name":"环境保护(英文)","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46458983","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}
Arthur Kaniki Tshamala, Mathieu Kayembe Musala, Gigi Kasongo Kalenga, Hugues Dibwe wa Mumapanda
The study focuses on the assessment of the surface water quality of the mining city of Kakanda (Lualaba Province in the DRC) to highlight pollution from mining activity. In addition to literature research, the identification of mining activities and the location of rivers and streams, the methodology adopted consisted in analyzing the water upstream and downstream of different discharge points of final effluents. The choice of parameters was made according to the Congolese legislation on this subject. Field observations indicated that liquid effluents from mining plants are discharged into the natural environment through drains. Chemical analyses have shown that the waters of these drains are loaded with metals at concentrations tens of times higher than standards. The results of the physicochemical analyses also indicated a deterioration of the quality of the water downstream of the discharge points. The level of suspended solids reaches 182 mg/l for an acceptable level of 80 mg/l. The concentration of cobalt and manganese in the streams receiving the final effluents reaches, respectively, 0.659 mg/l and 1.709 mg/l for an acceptable threshold of 0.5 mg/l. The electrical conductivity, the chemical composition as well as the other parameters exploited have revealed pollution of mining origin.
{"title":"Assessment of Surface Water Quality in Kakanda: Detection of Pollution from Mining Activities","authors":"Arthur Kaniki Tshamala, Mathieu Kayembe Musala, Gigi Kasongo Kalenga, Hugues Dibwe wa Mumapanda","doi":"10.4236/jep.2021.129035","DOIUrl":"https://doi.org/10.4236/jep.2021.129035","url":null,"abstract":"The study focuses on the assessment of the surface water quality of the mining city of Kakanda (Lualaba Province in the DRC) to highlight pollution from mining activity. In addition to literature research, the identification of mining activities and the location of rivers and streams, the methodology adopted consisted in analyzing the water upstream and downstream of different discharge points of final effluents. The choice of parameters was made according to the Congolese legislation on this subject. Field observations indicated that liquid effluents from mining plants are discharged into the natural environment through drains. Chemical analyses have shown that the waters of these drains are loaded with metals at concentrations tens of times higher than standards. The results of the physicochemical analyses also indicated a deterioration of the quality of the water downstream of the discharge points. The level of suspended solids reaches 182 mg/l for an acceptable level of 80 mg/l. The concentration of cobalt and manganese in the streams receiving the final effluents reaches, respectively, 0.659 mg/l and 1.709 mg/l for an acceptable threshold of 0.5 mg/l. The electrical conductivity, the chemical composition as well as the other parameters exploited have revealed pollution of mining origin.","PeriodicalId":59176,"journal":{"name":"环境保护(英文)","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41852773","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}
Shirendev Nasanjargal, Bat-Amgalan Munkhpurev, N. Kano, Hee-Joon Kim, Yu Ganchimeg
In this study, the removal of Cr(VI) from aqueous solution by modified zeolite with 3-aminopropyltriethoxysilane was investigated. The effect of various parameters such as pH, contact time, temperature, initial concentration of Cr(VI) ion, common cations, and anions on the adsorption of Cr(VI) was studied. The modified zeolite was characterized by following instrumental analysis of XRD, SEM/EDS, BET, and FT-IR. Based on calculated thermodynamic parameters values (ΔG0 H0 > 0, and ΔS0 > 0) and kinetic properties of the adsorption of Cr(VI) by modified zeolite, it was concluded that the rate-limiting step of the process is a second-order chemical reaction. The results of the adsorption isotherm study confirmed that the adsorption follows the Langmuir isotherm model. The maximum adsorption capacity was 13.5 mg/g.
{"title":"The Removal of Chromium(VI) from Aqueous Solution by Amine-Functionalized Zeolite: Kinetics, Thermodynamics, and Equilibrium Study","authors":"Shirendev Nasanjargal, Bat-Amgalan Munkhpurev, N. Kano, Hee-Joon Kim, Yu Ganchimeg","doi":"10.4236/jep.2021.129040","DOIUrl":"https://doi.org/10.4236/jep.2021.129040","url":null,"abstract":"In this study, the removal of Cr(VI) from aqueous solution by modified zeolite with 3-aminopropyltriethoxysilane was investigated. The effect of various parameters such as pH, contact time, temperature, initial concentration of Cr(VI) ion, common cations, and anions on the adsorption of Cr(VI) was studied. The modified zeolite was characterized by following instrumental analysis of XRD, SEM/EDS, BET, and FT-IR. Based on calculated thermodynamic parameters values (ΔG0 H0 > 0, and ΔS0 > 0) and kinetic properties of the adsorption of Cr(VI) by modified zeolite, it was concluded that the rate-limiting step of the process is a second-order chemical reaction. The results of the adsorption isotherm study confirmed that the adsorption follows the Langmuir isotherm model. The maximum adsorption capacity was 13.5 mg/g.","PeriodicalId":59176,"journal":{"name":"环境保护(英文)","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44636417","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}
Amal A. Al Mousa, N. Moubayed, Amani M. Al Jaloud, Fatima S. Al Khattaf, Noura D. Dahmasha
Valorizing chicken feather agro-wastes nowadays is imperative, if these wastes are disposed of without treatment, they could contribute to environmental problems. Conventional methods of processing chicken feathers such as landfilling, chemical treatment and burning are costly, non-time consumable and are toxic to the environment. Microbial hydrolysis, on the contrary, is now considered the main environmental-friendly recycling alternative. Hence, the aim of this study is to isolate keratinolytic bacteria with efficient feather hydrolysis, to optimize some of the physical parameters that could affect both bacterial growth and consequently its degrading ability. Results demonstrated an efficient feather degrading ability of newly identified Bacillus sp. D4 strain isolated from chicken feathers under optimal mesophilic temperature 37°C, pH 8.0 and 106 CFU/mL cell size inoculum, interpreted by highest keratin activity (55.0 ± 1.35 U/mL) and (54.3 ± 1.5 U/mL) respectively and higher total protein content in the cell free supernatant of 0.65 mg/mL. Beyond these parameters values, a moderate enzyme activity was observed at 40°C (35.1 ± 2 U/mL), 25°C (30.1 ± 2 U/mL), similarly at the initial pH 7.5 (52.3 ± 2 U/mL), pH 9.0 (49.0 ± 1.2 U/mL) and pH 10.0 (38.2 ± 1.35 U/mL). Bacillus sp. D4, on the other hand, was not able to tolerate high alkaline pH value 11.0 nor acidic pH 4.0 and 5.0 and high temperature of 55°C, correspondingly low enzyme activity was noted (19.0 ± 1 U/mL).
{"title":"Chicken Feathers Waste Management by Microbial as a Sustainable and Tool Environmental Friendly","authors":"Amal A. Al Mousa, N. Moubayed, Amani M. Al Jaloud, Fatima S. Al Khattaf, Noura D. Dahmasha","doi":"10.4236/jep.2021.129039","DOIUrl":"https://doi.org/10.4236/jep.2021.129039","url":null,"abstract":"Valorizing chicken feather agro-wastes nowadays is imperative, if these wastes are disposed of without treatment, they could contribute to environmental problems. Conventional methods of processing chicken feathers such as landfilling, chemical treatment and burning are costly, non-time consumable and are toxic to the environment. Microbial hydrolysis, on the contrary, is now considered the main environmental-friendly recycling alternative. Hence, the aim of this study is to isolate keratinolytic bacteria with efficient feather hydrolysis, to optimize some of the physical parameters that could affect both bacterial growth and consequently its degrading ability. Results demonstrated an efficient feather degrading ability of newly identified Bacillus sp. D4 strain isolated from chicken feathers under optimal mesophilic temperature 37°C, pH 8.0 and 106 CFU/mL cell size inoculum, interpreted by highest keratin activity (55.0 ± 1.35 U/mL) and (54.3 ± 1.5 U/mL) respectively and higher total protein content in the cell free supernatant of 0.65 mg/mL. Beyond these parameters values, a moderate enzyme activity was observed at 40°C (35.1 ± 2 U/mL), 25°C (30.1 ± 2 U/mL), similarly at the initial pH 7.5 (52.3 ± 2 U/mL), pH 9.0 (49.0 ± 1.2 U/mL) and pH 10.0 (38.2 ± 1.35 U/mL). Bacillus sp. D4, on the other hand, was not able to tolerate high alkaline pH value 11.0 nor acidic pH 4.0 and 5.0 and high temperature of 55°C, correspondingly low enzyme activity was noted (19.0 ± 1 U/mL).","PeriodicalId":59176,"journal":{"name":"环境保护(英文)","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48421517","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}
The discharge of pharmaceuticals via wastewater into the environment is a great concern due to the constant threat posed to photosynthetic organisms since they are vital for the sustenance of the aquatic food web. To compare the photosynthetic and growth responses of green algae to human antibiotics, Raphidocelis subcapitata and Chlorella vulgaris were exposed to erythromycin and sulfamethoxazole for 96 h. A much higher sensitivity was shown by Raphidocelis to the antibiotics. Although erythromycin was more acutely toxic to photosynthesis (EC50, 24.6 μg/L; EC10, 14.6 μg/L) than growth (EC50, 160 μg/L; EC10, 27 μg/L) in Raphidocelis, chronic effects in terms of EC10 were alike. Interestingly, sulfamethoxazole exhibited similar toxicity towards growth and photosynthesis with the acute and chronic toxicity parameters for growth (EC50, >2000 μg/L; EC10, 260 μg/L for Raphidocelis; and EC50, 47,900 μg/L; EC10, 19,100 μg/L for Chlorella) in consonance with those of photosynthesis (EC50, >2000 μg/L; EC10, 340 μg/L for Raphidocelis; and EC50, 47,500 μg/L; EC10, 13,400 μg/L for Chlorella). Growth and photosynthesis in Raphidocelis were strongly inhibited in this study at environmentally relevant concentrations of erythromycin. The findings from this study demonstrated that photosynthetic yield was a reliable indicator of sulfamethoxazole and erythromycin effects and thus, may be useful as an alternative approach to growth in assessing chronic toxicity in antibiotics.
{"title":"Microalgal Exposure to Human Antibiotics Triggers Similarities in Growth and Photosynthetic Responses","authors":"Adeolu O. Aderemi, J. Roberts, C. Hunter, O. Pahl","doi":"10.4236/jep.2021.128032","DOIUrl":"https://doi.org/10.4236/jep.2021.128032","url":null,"abstract":"The discharge of pharmaceuticals via wastewater into the environment is a great concern due to the constant threat posed to photosynthetic organisms since they are vital for the sustenance of the aquatic food web. To compare the photosynthetic and growth responses of green algae to human antibiotics, Raphidocelis subcapitata and Chlorella vulgaris were exposed to erythromycin and sulfamethoxazole for 96 h. A much higher sensitivity was shown by Raphidocelis to the antibiotics. Although erythromycin was more acutely toxic to photosynthesis (EC50, 24.6 μg/L; EC10, 14.6 μg/L) than growth (EC50, 160 μg/L; EC10, 27 μg/L) in Raphidocelis, chronic effects in terms of EC10 were alike. Interestingly, sulfamethoxazole exhibited similar toxicity towards growth and photosynthesis with the acute and chronic toxicity parameters for growth (EC50, >2000 μg/L; EC10, 260 μg/L for Raphidocelis; and EC50, 47,900 μg/L; EC10, 19,100 μg/L for Chlorella) in consonance with those of photosynthesis (EC50, >2000 μg/L; EC10, 340 μg/L for Raphidocelis; and EC50, 47,500 μg/L; EC10, 13,400 μg/L for Chlorella). Growth and photosynthesis in Raphidocelis were strongly inhibited in this study at environmentally relevant concentrations of erythromycin. The findings from this study demonstrated that photosynthetic yield was a reliable indicator of sulfamethoxazole and erythromycin effects and thus, may be useful as an alternative approach to growth in assessing chronic toxicity in antibiotics.","PeriodicalId":59176,"journal":{"name":"环境保护(英文)","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45479054","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}
Gullies in semi-arid region are important in landscape modification, degradation and increased overland flow affecting geomorphic thresholds of an area. Gullies generate about 95% of global sediment load, important in landscape modification, degradation and increased overland flow in semi-arid regions, but little is known on geomorphic factors that increase ecological fragility increasing gully initiation. To address the problem, landscape regions of accelerated geomorphic processes must be determined. The study aimed to establish topographical thresholds and geomorphic factors which increase landscape fragility in gully head positions in different geographical regions. Gully heads were analyzed by detailed field surveys from 10 m up and down-slope position. Drainage area contributing to gully was demarcated from the point overland flow was assumed to reach the gully head based on water visible flow-lines while gully head slopes were determined by use of clinometers. Gully threshold concept was applied to identify the critical slope (S) and drainage area (A), using appropriate S - A relation (S = aAb) and verified using ANOVA. The empirical S - A threshold relation S = 0.383A-0.397, R2 = 0.0321 (upper-segment), S = 0.174A-0.032, R2 = 0.498 (mid-segment), S = 0.23A-0.020, R2 = 0.088 (lower segment), represented approximate critical slope-drainage area for gully initiation and regions of dominant geomorphic processes, above which gully initiation was likely to occur. Negative b values represent an areas more dominated by overland flow over sub-surface processes. Coefficient of correlation multiple R = 0.7055 (70.55%) Mid-segment indicated strong relation slope-drainage area for gully initiation. ANOVA analysis p = 0.01, 0.004 and 0.4498 for upper, mid and lower segment respectively revealed stronger relation between independent and dependent variables. p > 0.05 indicated regions influenced by more factors than slope and drainage area. Thus, slope-drainage threshold relation line can be applied in the semi-arid environments to locate vulnerable sites of dominant geomorphic processes which should be checked for gully conservation.
{"title":"Geomorphic Threshold for Gully Initiation in Different Geographical Environments of Wanjoga River Catchment, Tana Basin, Kenya","authors":"Cecilia Ireri, G. Krhoda, Mikalitsa S. Mukhovi","doi":"10.4236/jep.2021.128034","DOIUrl":"https://doi.org/10.4236/jep.2021.128034","url":null,"abstract":"Gullies in semi-arid region are important in landscape modification, degradation and increased overland flow affecting geomorphic thresholds of an area. Gullies generate about 95% of global sediment load, important in landscape modification, degradation and increased overland flow in semi-arid regions, but little is known on geomorphic factors that increase ecological fragility increasing gully initiation. To address the problem, landscape regions of accelerated geomorphic processes must be determined. The study aimed to establish topographical thresholds and geomorphic factors which increase landscape fragility in gully head positions in different geographical regions. Gully heads were analyzed by detailed field surveys from 10 m up and down-slope position. Drainage area contributing to gully was demarcated from the point overland flow was assumed to reach the gully head based on water visible flow-lines while gully head slopes were determined by use of clinometers. Gully threshold concept was applied to identify the critical slope (S) and drainage area (A), using appropriate S - A relation (S = aAb) and verified using ANOVA. The empirical S - A threshold relation S = 0.383A-0.397, R2 = 0.0321 (upper-segment), S = 0.174A-0.032, R2 = 0.498 (mid-segment), S = 0.23A-0.020, R2 = 0.088 (lower segment), represented approximate critical slope-drainage area for gully initiation and regions of dominant geomorphic processes, above which gully initiation was likely to occur. Negative b values represent an areas more dominated by overland flow over sub-surface processes. Coefficient of correlation multiple R = 0.7055 (70.55%) Mid-segment indicated strong relation slope-drainage area for gully initiation. ANOVA analysis p = 0.01, 0.004 and 0.4498 for upper, mid and lower segment respectively revealed stronger relation between independent and dependent variables. p > 0.05 indicated regions influenced by more factors than slope and drainage area. Thus, slope-drainage threshold relation line can be applied in the semi-arid environments to locate vulnerable sites of dominant geomorphic processes which should be checked for gully conservation.","PeriodicalId":59176,"journal":{"name":"环境保护(英文)","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44119734","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}
E. Agbalagba, S. Egarievwe, E. A. Odesiri-Eruteyan, Mebougna L. Drabo
The evaluation of gross alpha and beta activities in crude oil contaminated soil, sediment and water samples was conducted in ten oil polluted environment of Delta State using Gas-flow proportional counter. Samples were collected from the oil polluted environment in each oil field and samples were prepared and analyzed following standard procedures. The mean gross alpha and beta activities obtained are 331.4 ± 24.5 Bq kg-1 and 11,335 ± 112 Bq kg-1 respectively for soil, 259.2 ± 17.6 Bq kg-1 and 4508 ± 96 Bq kg-1 respectively for sediment, and 1.00 ± 0.09 Bq kg-1 and 20.3 ± 1.7 Bq kg-1 respectively for water. The estimated average values of the total annual effective dose equivalent (AEDET (α,β)), the total annual gonadal dose equivalent (AGDET (α,β))), and the total excess lifetime cancer risk (ELCRT (α,β)) are 10.64 mSv y-1, 0.037 μSv y-1 and 0.037 μSv y-1 respectively. The gross alpha and beta activities values obtained in soil and sediment were relatively high compared to values reported in some parts of the country and other regions and countries of the world. The radiological risk parameters examined show that AEDET (α,β) and AGDET (α,β) are above recommended permissible limits while ELCRT (α,β) is within the recommended permissible limit. The overall results obtained in this study indicate that the environmental samples have been radiologically impaired due to the crude oil spillage. An appropriate remediation technique was therefore recommended to remediate the polluted soil, sediment, and water to their near original state.
{"title":"Evaluation of Gross Alpha and Gross Beta Radioactivity in Crude Oil Polluted Soil, Sediment and Water in the Niger Delta Region of Nigeria","authors":"E. Agbalagba, S. Egarievwe, E. A. Odesiri-Eruteyan, Mebougna L. Drabo","doi":"10.4236/jep.2021.128033","DOIUrl":"https://doi.org/10.4236/jep.2021.128033","url":null,"abstract":"The evaluation of gross alpha and beta activities in crude oil contaminated soil, sediment and water samples was conducted in ten oil polluted environment of Delta State using Gas-flow proportional counter. Samples were collected from the oil polluted environment in each oil field and samples were prepared and analyzed following standard procedures. The mean gross alpha and beta activities obtained are 331.4 ± 24.5 Bq kg-1 and 11,335 ± 112 Bq kg-1 respectively for soil, 259.2 ± 17.6 Bq kg-1 and 4508 ± 96 Bq kg-1 respectively for sediment, and 1.00 ± 0.09 Bq kg-1 and 20.3 ± 1.7 Bq kg-1 respectively for water. The estimated average values of the total annual effective dose equivalent (AEDET (α,β)), the total annual gonadal dose equivalent (AGDET (α,β))), and the total excess lifetime cancer risk (ELCRT (α,β)) are 10.64 mSv y-1, 0.037 μSv y-1 and 0.037 μSv y-1 respectively. The gross alpha and beta activities values obtained in soil and sediment were relatively high compared to values reported in some parts of the country and other regions and countries of the world. The radiological risk parameters examined show that AEDET (α,β) and AGDET (α,β) are above recommended permissible limits while ELCRT (α,β) is within the recommended permissible limit. The overall results obtained in this study indicate that the environmental samples have been radiologically impaired due to the crude oil spillage. An appropriate remediation technique was therefore recommended to remediate the polluted soil, sediment, and water to their near original state.","PeriodicalId":59176,"journal":{"name":"环境保护(英文)","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41849615","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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