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Treatment of Acid Mine Drainage Using Constructed Wetland in Tropical Environment： A Tanzania Case Report

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Journal of Agricultural Science and Technology(B) 2013年第6期3卷 439-446页

作者： Jamidu Hizzam yahaya Katima Leonard Gastory Lugali Karoli Nicholas Njau WSP & CW Research and Development Group College of Engineering and Technology University of Dar Es Salaam Dar EsSalaam Tanzania WWS Design and Development Company Limited Dar Es Salaam Tanzania Department of Water and Environmental Science and Engineering the Nelson Mandela African Institute of Science andTechnology Arusha Tanzania

The suitability of constructed wetland （CW） in were developed. The first experiment focused on zinc and treating acid mine drainage （AMD） was investigated. Two experiments nutrients removals. Four units of horizontal subsurface flow CWs were used, two cells planted with Phragmites mauritianus, one cell with Typha domingensis and one cell unplanted （control cell）. Artificial high concentrated AMD was used. It was mixed with domestic wastewater from the anaerobic waste stabilization pond （WSP） to ensure nutrient supply to the plants in the CW cells. The second experiment tested the tolerance of locally available macrophytes to the harsh acidic environment, while providing required condition for treatment of AMD. To accomplish this, another set of four CW cells planted with different types of macrophytes, namely Typha domingensis, Phragmites mauritianus, Vetiver grass and Papyrus, were used thereby subjecting them to varying acid concentration ofpH of 3.5, 3.0, 2.9 and 2.7. The study demonstrated adequate zinc removal from AMD which is related to sulphide precipitation. A CW cell planted with Typha domingensis showed higher zinc removal （80%-84%） compared to other cells. Different macrophytes showed different nutrient removal efficiency, but overall, for the type of wetland plants studied, phosphorous removal increased with decreasing pH while nitrogen removal behaved quite opposite. On the other hand, Typha domingensis, Phragmites mauritianus and Papyrus were observed to tolerate high acidity as low pH as 2.7 and therefore are suitable macrophytes for AMD treatment with CW.

关键词： Constructed wetland acid mine drainage passive system zinc removal suitable macrophytes

Spatial Variation and Trend of Extreme Precipitation in Africa during 1981-2019 and Its Projected Changes at the End of 21^st Century

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Journal of Geoscience and Environment Protection 2024年第3期12卷 192-221页

作者： Fabien Habiyakare Tong Jiang Ibrahim yahaya Daudi Ndabagenga James Kagabo Buda Su School of Atmospheric Sciences Key Laboratory of Meteorological Disaster of Ministry of Education Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters Nanjing University of Information Science and Technology Nanjing China Rwanda Meteorology Agency (Meteo Rwanda) Kigali Rwanda Institute for Disaster Risk Management/School of Geographical Sciences Nanjing University of Information Science & Technology Nanjing China Department of Geography Gombe State University Gombe State Nigeria

This study comprehensively examines the patterns and regional variation of severe rainfall across the African continent, employing a suite of eight extreme precipitation indices. The analysis extends to the assessment of projected changes in precipitation extremes using five General Circulation Models (GCMs) from Coupled Model Intercomparison Project Phase 6 (CMIP6) under four Shared Socioeconomic Pathways (SSPs) scenarios at the long-term period (2081-2100) of the 21st century. Furthermore, the study investigates potential mechanisms influencing precipitation extremes by correlating extreme precipitation indices with oceanic system indices, specifically Ni?o 3.4 for El Ni?o-Southern Oscillation (ENSO) and Dipole Mode Index (DMI) for the Indian Ocean Dipole (IOD). The findings revealed distinct spatial distributions in mean trends of extreme precipitation indices, indicating a tendency toward decreased extreme precipitation in North Africa, Sahel region, Central Africa and the Western part of South Africa. Conversely, West Africa, East Africa and the Eastern part of South Africa exhibit an inclination toward increased extreme precipitation. The changes in precipitation extreme indices indicate a general rise in both the severity and occurrence of extreme precipitation events under all scenarios by the end of the 21st century. Notably, our analysis projects a decrease in consecutive wet days (CWD) in the far-future. Additionally, correlation analysis highlights significant correlation between above or below threshold rainfall fluctuation in East Africa and South Africa with oceanic systems, particularly ENSO and the IOD. Central Africa abnormal precipitation variability is also linked to ENSO with a significant negative correlation. These insights contribute valuable information for understanding and projecting the dynamics of precipitation extreme in Africa, providing a foundation for climate adaptation and mitigation efforts in the region.

关键词： Extreme Precipitation Mann-Kendall Trend Projections Oceanic System Africa

Assessment of the Level of Knowledge of the Nature of Highly Pathogenic Avian Influenza Demonstrated by the Nigerian Veterinary Laboratory Staff Involved in HPAI Diagnosis in Nigeria

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Open Journal of Veterinary Medicine 2015年第4期5卷 89-92页

作者： Bello Rabi’u Alkali Kyauta Bulus Tanyigna yahaya Abubakar Yabo Department of Veterinary Microbiology Usmanu Danfodiyo University Sokoto Nigeria National Institute for Policy and Strategic Studies (NIPSS) Kuru Jos Nigeria Department of Veterinary Physiology and Biochemistry Usmanu Danfodiyo University Sokoto Nigeria

The study was designed to evaluate the level of knowledge of Nigerian Veterinary Laboratory Staff on the nature of Highly Pathogenic Avian Influenza (HPAI) disease using structured questionnaires. The study comprised the Staff of National Veterinary Research Institute (NVRI) and five reference Veterinary Teaching Hospitals (VTH) designated for HPAI diagnosis. A total of 69 questionnaires were distributed to the laboratory staff. Questions on the general nature of the disease such as the cause, signs, mode of transmission, methods of identification, lesions, control and prevention, etc. were asked. The results showed that 77.38% of the staff answered all the questions correctly indicating their considerable knowledge of the HPAI disease. Considerable percentage of the staff listed correctly the equipment used for serology (36.23%) and RT-PCR (31.88%). Interestingly only 13.04% of the staff listed correctly the equipment used in rapid tests despite the fact that they are simpler and recommended for all P2 laboratories. In conclusion, the veterinary laboratory staff assessed demonstrated a significant level of knowledge on HPAI diagnosis;however, most of their laboratories lack the structure, organization, funds and basic facilities required for effective HPAI diagnosis.

关键词： Assessment Veterinary Laboratory Highly Pathogenic Avian Influenza

Carbon emission efficiency of forest processing industries in China

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Ecological Economy 2023年第3期19卷 217-232页

作者： GUAN Zhi-jie yahaya Idris MUSA ZHANG Ya-xin GUO Zhi-yuan Wu Jinglian School of Economics Changzhou UniversityChangzhou 213164CHINA

This paper uses an input-output table of China's provinces(2007-2016) to measure carbon emissions of these *** employs a Malmquist-Luenberger(ML) index with expected and undesired outputs,and an absolute β convergence and a conditional β convergence model,to conduct an in-depth analysis of dynamic changes and spatial *** emission efficiency of forest processing industries in 25 regions,including Shanghai,Chongqing,Zhejiang,and Jiangsu are increasing,whereas those of Tianjin,Liaoning,Heilongjiang,and Tibet are *** main contributing factors of carbon emission efficiency in three major regions vary over ***,carbon emission efficiency in the eastern,central,and western regions all have absolute β convergence and conditional β convergence,indicating that different regions are developing toward their own goals and industry,yet regions with lower efficiency are catching up with those where with more efficient strategies in ***,this paper proposes according recommendations.

关键词： input-output model ML index convergence carbon emission efficiency forest industry production

Seasonal Effect on Weather Elements on Water Table Fluctuation in Potable Wells in Kono District, Eastern Sierra Leone

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Open Journal of Applied Sciences 2023年第11期13卷 2198-2209页

作者： Richard Tamba Simbo Alhaji Brima Gogra yahaya Kudus Kawa Paul Juana Moiwo Department of Chemistry School of Basic Sciences Njala University Bo Sierra Leone Department of Science and Mathematics William V.S. Tubman University Harper Liberia Ernest Bai Koroma University of Science and Technology Makeni Sierra Leone Department of Agricultural Engineering School of Technology Njala University Bo Sierra Leone

The study investigated the seasonal effects of weather elements on water table fluctuations in drinking wells in Nimikoro and Tankoro Chiefdoms in Kono District, Eastern Sierra Leone. The study specifically determined the trends in precipitation, air temperature and relative humidity relative to water table depth and water volume in both manually dug and mechanically drilled water wells in the chiefdoms. The key objective was to provide a clear guide on sustainable well development and operation in the study area and beyond. To do so, the depth of each well was taken and the water table measured. Also, data on key weather elements such as precipitation, air temperature and relative humidity were collected on the 15th of every month for a period of one year. The data were analyzed on Excel, SPSS and ArcGIS platforms for monthly and seasonal trends in the time-space fabric. The results showed that the depth to water table was high in the dries (small well water volume) and low in the rains (large well water volume) for both manually dug and mechanically drilled wells. Well water temperature increased as temperature increased during the dry season but decreased as temperature decreased during the rainy season. The study showed that weather elements such as precipitation and temperature had direct impact on groundwater availability. This is critical for groundwater development and management in the study area and in Sierra Leone at large.

关键词： Groundwater Water Table Relative Humidity Precipitation Temperature

Analysis of Urban Land Use and Land Cover Change for Sustainable Development: A Case of Lafia, Nasarawa State, Nigeria

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Journal of Geographic Information System 2019年第3期11卷 347-358页

作者： Banki Thomas Chunwate Sani yahaya Ishaya Kunden Samaila Shittu Whanda Ja’afaru Department of Geography Nasarawa State University Keffi Nigeria Department of Geography Gombe State University Gombe Nigeria

Inventories on land use/cover changes are assessed at increasing importance in various sectors, like agriculture, settlement, environmental studies and urban planning. This research was carried out to analyse the changes in urban land use/cover of Lafia for the years 1986, 2000 and 2014. Remotely sensed data from Landsat TM and Nigeria sat 8 were classified using GIS technique, to which six categories of land use/cover were identified such as: bare surfaces, built up areas, cultivated lands, rocky outcrops, vegetation cover and wetlands. Population data of the study area for 1986, 2000 and 2014 were also used to compare the relationship between population growth and landuse/cover changes in the study area using descriptive statistics. The result revealed an increase in built up areas from 1.56% to 15% between 1986 and 2014 while vegetation cover showed decrease: from 25% in 1986 to 12% in 2014. Cultivated lands increased from 56% in 1986 to 67% in 2014. Others classes such as: bare surfaces decreased, as wetlands and rock outcrops seem to be fluctuated. Therefore results from the analyses indicate a general change in landcover for the periods under this study. This study recommends that: there is a need to monitor the changes that occurred on land use so as to provide proper planning and effective management of the land resources in a sustainable manner.

关键词： Land Use/Cover Changes Sustainability Development GIS Application

Geo-Spatial Analysis of Oil Spill Distribution and Susceptibility in the Niger Delta Region of Nigeria

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Journal of Geographic Information System 2016年第4期8卷 438-456页

作者： Shittu Whanda Olalekan Adekola Bashir Adamu Sani yahaya Prem C. Pandey Environment and Safequard Unit Nigeria Erosion and Watershed Management Project (NEWMAP) Gombe State Nigeria

Oil spill occurrence during exploration, production and distribution can cause deleterious impact on the environment. Contamination of local streams/rivers, farmlands, forest resources and biodiversity in oil producing areas presents strong significant possibility of significant harm to human health. Geo-information technologies present new opportunities for assessing stress environment and ways of determining exposure susceptibility in such areas. The study assesses the geographical distribution of oil-spills cluster and pattern using three geospatial techniques with ground data at 443 oil-spill incident sites from 1985-2008. The places with high (high-volume/ large impact/close proximity to communities) and low incident (low-volume/less impact/far-distance) are related to the quantity of oil-spills identified within those communities considered susceptible to spill impact and possible exposure. While the average nearest neighborhood analysis showed a probability that oil-spill distribution in the area is clustered (ratio < 1 with index value 0.19), the Getis-Ord General G test indicated that the oil-spill with high quantities (volume) discharge are significantly clustered within every 400 m. The Moran’s I index indicted that there is <1% likelihood that the clusters are as a result of random chance. These findings will help to combat the environmental problems and risks of prolong exposure to petroleum hydrocarbons by addressing future incidents or relocating oil facilities/communities and positioning of rapid response strategies.

关键词： Oil Spills GIS Analysis Third Party Damage Interdiction Pollutant Linkages

Dynamics of Potable Well Water Quality in Key Mining Chiefdoms in Kono District, Eastern Sierra Leone

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Open Journal of Applied Sciences 2024年第7期14卷 1927-1943页

作者： Richard Tamba Simbo Alhaji Brima Gogra yahaya Kudus Kawa Juana Paul Moiwo Department of Science and Mathematics College of Arts and Sciences William V.S. Tubman University Harper Liberia Port Loko University College Campus Ernest Bai Koroma University of Science and Technology Port Loko Sierra Leone Department of Chemistry School of Basic Sciences Njala University Bo Sierra Leone Department of Agricultural Engineering School of Technology Njala University Bo Sierra Leone

Groundwater is increasingly being used due to its universal availability and generally good quality. However, the risk of contamination of groundwater due to various human activities such as mining is equally increasing across the globe. In this study, the physical parameters of potable well waters in the key mining areas in Nimikoro and Tankoro Chiefdoms in Kono District were analyzed for compliance with drinking water quality standard. To do this, both unpurged and purged well water samples were collected once every month for a period of one year. Some of the well water properties like temperature, Total Dissolved Solids (TDS) and Electrical Conductivity (EC) were measured on site and others determined in the laboratory. The data collected from the laboratory analyses were statistically analyzed in MS Excel, SPSS and ArcGIS environments for quality trends in time-space fabric. The results showed that well water quality in the study area generally fell short of drinking water quality standards of Sierra Leone and WHO. There were high temperature and turbidity during the dry season and then high TDS and EC during the rainy season. Temperature and turbidity also significantly influenced well water quality in the study area, much more than TDS and EC. The implications for drinking water of lower quality than the standard could be huge for the local population and therefore needs the attention of stakeholders in the study area and decision makers in the country.

关键词： Temperature Total Dissolved Solids Turbidity Electrical Conductivity Water Quality

Type 2 diabetes with good glycemic control have improved insulin response and lower non-esterified fatty acid level after a meal challenge

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Journal of Diabetes Mellitus 2012年第1期2卷 1-7页

作者： Norhayati yahaya Win Mar Kyi Norhayati Mohd Noor Wan Mohamed Wan Bebakar Endocrine Unit Department of Medicine Universiti Sains Malaysia Penang Malaysia

Background: Pathogenesis of type 2 diabetes (T2DM) involves defects in β-cell function with impaired first and second phase insulin response, and reduced insulin sensitivity. Diabetic dyslipidemia is an important and common risk factor for coronary heart disease (CHD). Aims: This study examined the effect of glycemic control on post prandial insulin and lipid parameters in response to a standardised meal challenge among Type 2 diabetes patients with good and poor glycemic control. Methods: We cross-sectionally studied 31 T2DM patients with good glycemic control and 32 T2DM patients with poor glycemic control. Subjects were given, after minimum 10 hours of fasting, a standard meal containing 58% fat. Fasting and serial postprandial blood samples were taken over 8 hours to determine levels of triglyceride, direct LDL-C, apoB lipoprotein, non-esterified-fatty-acid, insulin and blood glucose. Results: Post prandial NEFA was significantly higher in poor controlled diabetes patients compared to good control diabetes patients (p = 0.019), and post-hoc analysis showed significant difference from 3 hours post prandial to 4 hours post prandial, where p= 0.021. Although the difference in insulin between the 2 groups did not reach statistical significance (p =0.058), post-hoc analysis showed significant difference between the 2 groups from fasting to 1 hour post prandial (p = 0.034) despite postprandial glucose being significantly higher in poor controlled diabetes patients (p < 0.001), throughout the postprandial period. Conclusion: T2DM patients with good glycemic control have improved insulin response with lower non-esterified fatty acid.

关键词： Insulin Response Non-Esterified Fatty Acid Standardised Meal Type 2 Diabetes Glycemic Control