African Journal of Water Conservation and Sustainability

African Journal of Water Conservation and Sustainability ISSN: 2375-0936 Vol. 6 (1), pp. 001-013, January, 2018. © International Scholars Journals

Full Length Research Paper

Experimental study of methylene blue adsorption from aqueous solutions onto carbon nano tubes

Zohre Shahryari, Ataallah Soltani Goharrizi* and Mehdi Azadi

Department of Chemical Engineering, College of Engineering, Shahid Bahonar University of Kerman, Kerman, Iran.

Accepted 09 December, 2017

Abstract 

In this work, batch adsorption experiments were carried out for the removal of methylene blue as a basic dye from aqueous solutions using carbon nanotubes (CNTs). The effects of major variables governing the efficiency of the process such as, temperature, initial dye concentration, CNTs dosage, and pH were investigated. Experimental results have shown that, the amount of dye adsorption increased with increasing the initial concentration of the dye, CNTs dosage, and temperature. The dye removal using 400 mg L-1 of CNTs was more than 90%. This dosage (400 mg L-1) was considered as the optimum dosage of CNTs to remove methylene blue. The adsorption kinetic data were analysed using pseudo-first-order, pseudo-second -order and Elovich models. It was found that the pseudo-second-order kinetic model was the most appropriate model, describing the adsorption kinetics. Adsorption isotherm of methylene blue onto the CNTs was determined at 290, 300 and 310 K with 10 mg L-1 as initial concentration of methylene blue. Adsorption equilibrium was attained within 120 min. Equilibrium data were fitted to the Langmuir, Freundlich, Temkin and Sips isotherm models and isotherm constants were determined. The equilibrium data were best represented by the Sips isotherm model. Thermodynamic parameters such as changes in the free energy of adsorption ( G ), enthalpy ( H ) and entropy ( S ) were calculated. The negative values of G indicate that the methylene blue adsorption process is spontaneous in nature and the positive value of H shows the endothermic nature of the process.

Key words: Carbon nanotubes, methylene blue, basic dye, adsorption, equilibrium, kinetic, thermodynamics.

African Journal of Water Conservation and Sustainability ISSN: 2375-0936 Vol. 5 (5), pp. 227-234, May, 2017. © International Scholars Journals

Full Length Research Paper

Assessment of farmers’ practices on soil erosion control and soil fertility improvement in rift valley areas of east Shoa and west Arsi zones of Oromia, Ethiopia

¹Tesfaye Gemechu and ²Kasahun Kitila*

¹Agricultural Extension researcher at Adami Tulu Agricultural research center, Ziway, Ethiopia, ²Soil and water conservation researcher at ATARC.

*Corresponding author Email:  [email protected]. Tel: +251912855363

Accepted 13 July, 2014

Abstract

Farmers’ perception and indigenous knowledge to conserve natural resources in general and soil and water conservation in particular have received little emphasis in Ethiopia. This study aimed to understand farmers’ perception on prevalence of soil erosion and their indigenous mechanism in soil erosion control and soil fertility management. The study was conducted in March, 2011 in purposively selected districts of East Showa Zone (Adama and Lume districts) and West Arsi zones (Shashemene and Kofele) of Oromia, Ethiopia. Data was collected using household interviews where a total of 160 farmers were randomly selected and interviewed. It was identified that the land allocated for the agricultural land and forest land showed an increasing trends since five years back in all study districts while the land allocated for grazing was decreasing. This was due to conversion of grazing land and other marginal lands into cropland to satisfy an increased food demand. Water and wind erosions are the two major types of soil erosion identified in this particular study. Heavy and erratic rain fall, topography and deforestation are the major causes of soil erosion in all study area. To tackle the soil erosion problem, farmers are using different physical structures such as soil bund, cutoff drains and micro basins. In addition, crop rotation, compost, animal manure and intercropping are also the major biological soil and water conservation activities practiced by the farmers. In their decisions for fertilization or production farmers use yield response, soil color, vegetation cover, soil type and topography as soil fertility indicators. Chemical fertilizers, though perceived expensive, are still the dominant strategy used by farmers to increase production. In addition, farmers’ perception and training on use of other alternative organic fertilizer is very low in all study areas.

Keywords: Farmers’ practice, soil erosion, soil and water conservation.

African Journal of Water Conservation and Sustainability ISSN: 2375-0936 Vol. 5 (5), pp. 221-226, May, 2017. © International Scholars Journals

Full Length Research Paper

Studies on regression analysis between electrical conductivity and total dissolved solids as environmental variables in lower river Benue, Makurdi, Nigeria

Akaahan TJA¹* Olabanji, F. M.² and Azua ET¹

¹Department of Biological Sciences University of Agriculture, P.M.B. 2373 Makuedi Benue state Nigeria.

²Department of Environmental Biotechnology, National Biotechnology Agency Abuja Nigeria.

*Corresponding author E-mail: [email protected]. Tel: +2348037737675

Accepted 21 May, 2017

Abstract

This study investigated the relationship between electrical conductivity and total dissolved solids as environmental variables at five different Sites downstream in lower River Benue at Makurdi. The study sites were selected based on the human activities and land-water interface on the bank of the lower river Benue at Makurdi. Water Samples for the determination of conductivity and total dissolved solids were collected on monthly basis for a period of 24 months and were examined using standard methods for the two parameters. The results of the mean conductivity of the water samples at the sampling sites varied from 64.70±37.00- 139.60±215.10µS/cm while the mean concentration of total dissolved solids ranged from 28.30±11.70- 69.10±106.60mg/L. The R² value of regression analysis varied from 0.3417- 0.7967, indicating a weak to strong relationship between conductivity and total dissolved solids across the sampling sites downstream in lower River Benue at Makurdi. There was no perfect direct linear relationship between conductivity and total dissolved solids in River Benue at the sampling sites. The study concludes that the relationship between conductivity and total dissolved solids is nonlinear but depends on the mobility of dissolved dominant ions in the water sample or solution.

Keywords: Conductivity, TDS, river Benue, regression.

African Journal of Water Conservation and Sustainability ISSN: 2375-0936 Vol. 5 (5), pp. 206-220, May, 2017. © International Scholars Journals

Full Length Research Paper

Modeling the impact of water and nutrient management in African agriculture

Marco Pastori, Fayçal Bouraoui, Alberto Aloe

European Commission Joint Research Centre (JRC), Institute for Environment and Sustainability (IES), via E. Fermi 2749, I-21027 Ispra (VA), Italy.

*Corresponding auth: E-mail: [email protected] Tel: +390332785173

Accepted 4 February, 2015

Abstract

Africa has to adapt to the growing demand for agricultural commodities driven by growth in population, per capita income and new demands for biofuel. There is a wide agreement that African agriculture has enormous potential for growth and will shift towards a more productive farming. A systematic approach is needed to identify the main factors that explain observed yield gaps and to evaluate the impacts of a potential intensification on the environment. In this paper we presented a crop yield gap analysis for Africa using a newly developed tool linking a Geographic Information System and the biophysical model EPIC. We showed that in most African countries, the main limiting factor to crop production is nitrogen, while water limitation is more restricted to few countries. The predicted yield gap is much more marked in Sub-Saharan Africa than in North Africa. We predicted that a mining of soil resources, with nitrogen crop uptake exceeding the inputs through fertilization, is taking place in many countries in Africa. We also showed that even in water rich countries, appropriate water management including the development of irrigation infrastructure is needed to close the yield gap.

Key words: Water management, nitrogen requirements, irrigation requirements, yield gap, Africa, Epic.

African Journal of Water Conservation and Sustainability ISSN: 2375-0936 Vol. 5 (4), pp. 201-205, April, 2017. © International Scholars Journals

Full Length Research Paper

Evaluation of the radiation dose from radon ingestion and inhalation in drinking water

A. Binesh¹*, S. Mohammadi², A. A. Mowlavi2 and P. Parvaresh²

¹Department of Physics, Payam Nour University, Fariman, Iran.

²Department of Physics, Payam Nour University, Mashhad, Iran.

*Corresponding author. E-mail: [email protected].

Accepted 13 August, 2010

Abstract

Radon and its radioactive progenies in indoor places are recognized as the main sources of public exposure from the natural radioactive sources. The tap water used for drinking and other household uses can increase the indoor radon level. In the present research, drinking water samples were collected from various places and supplies of public water used in Mashhad city which has about 4 million population. Then radon concentration has been measured by PRASSI system three times for each sample. Results show that about 75% of water samples have radon concentration gathered than 10 Bq/L which advised EPA as a normal level. According to measurements data, the arithmetic mean of radon concentration for all samples was 16.238 ± 9.322 Bq/L. Similarly, the annual effective dose in stomach and lung per person has been evaluated in this research. According to the advice of WHO and EU Council, just 2 samples induced the total annual effective dose greater than 0.1 mSv/y.

Key words: Radon, effective dose, drinking water, PRASSI system, Mashhad city.