Optimization of manganese adsorption by ferromanganese ore and humus mixture using three-factor response surface methodology
N.M. Kamal1,2, H.A. Aziz1,3*, H. Hussin4
HIGHLIGHTS
Manganese adsorption from wastewater using mixture of ferromanganese ore and humus is proposed.
Dosage, pH and contact time are the main factors in governing effectiveness of Mn removal.
Optimization of the experimental factors using Response Surface Methodology yields an excellent removal of Mn.
R2 value from the regression analysis was 0.9783 which signifies that the fitness of the model is good.
ABSTRACT
In this study, mixture of ferromanganese ore and humus were used to investigate the optimum conditions of dosage, pH and contact time for manganese (Mn) adsorption by using Response Surface Methodology (RSM). Experimental design had involved three operating variables i.e. dosage (2 to 4 g), pH (3 to 7.5) and contact time (90 to 270 min) with an associated response of manganese adsorption (%). Experimental data was obtained from the adsorption study then fitted to a second order polynomial regression model. Regression analysis and analysis of variance (ANOVA) were used to examine the fitness of the model towards the data. R2 value from the regression analysis was 0.9783 which signifies that the fitness of the model is good. The F-value was 50.21 and the p-value (Prob >F) was less than 0.05 indicate that the model terms are significant at 95% confidence level. Optimum conditions given by the model were 3.79 g of the mixture dosage, pH of 6.47 and contact time of 124.59 min with 93.82% of Mn adsorption. These values had been successfully verified.
To cite this article: Kamal NM, Aziz HA, Hussin H. Optimization of manganese adsorption by ferromanganese ore and humus mixture using three-factor response surface methodology. Journal of Desalination and Water Purification 2018;10:13-18.
A review on cost effective municipal wastewater treatment options: Lessons for Sub-Saharan Africa
Gideon Abagna Azunre
HIGHLIGHTS
There is a high quality of treated water with the limited construction cost of wetlands.
A hybrid system of lagoon and wetland can also be used.
The constructed wetlands will serve as the final purification site for effluent.
ABSTRACT
Wastewater discharge contaminates both surface water and groundwater. Sub-Saharan African countries mostly found in the lower and middle-income status face difficulties in treating wastewater. Several forms of treating municipal wastewater have been adopted in these countries, which received critiques in the conventional literature. Therefore, the purpose of this study was to identify the major treatment technologies employed by Sub-Saharan African countries. This identified the major treatment technologies, such as stabilization ponds, constructed wetlands and aerated lagoons, that are mostly used in countries like Tanzania, Ghana and Kenya. The results show that there is a high quality of treated water with the limited construction cost of wetlands. As a result, the study ranked the constructed wetlands as the best. In order to address the critique of algae blooms and high-energy consumption of the existing technologies used in Sub-Saharan Africa, an emerging technology has been recommended. This technology makes use of algae to produce oxygen for bacteria to help in biochemical activity. This can help prevent the usage of aerators and blowers, which consume a lot of energy to introduce air. A hybrid system of lagoon and wetland can also be used to solve algae blooms. The constructed wetlands will serve as the final purification site for effluent from ponds before they discharge to surface water bodies.
To cite this article: Azunre GA. A review on cost effective municipal wastewater treatment options: Lessons for Sub-Saharan Africa. Journal of Desalination and Water Purification 2018;10:2-12.
Nanoparticles in heterogeneous photocatalytic treatment
Süreyya Meriç
Ensuring reliable access to affordable and safe sources of water is critical to both global health and economic development. Chemicals of emerging concern (CECs) have come in the agenda as an emerging issue [1] to evaluate performance of water treatment processes that urge the use of advanced technologies using new materials such as nanoparticles [2]. “Nano” particles have particular aspects that are favored as high surface areas, hyper-catalytic functions, tunable physical properties and faster kinetics [3]. Photocatalyst materials have been adapted for visible light activated disinfection by dye sensitized, plasmon sensitized and semiconductor sensitized routes. The mechanism of reactive oxygen specie (ROS) generation in these materials is generally driven through oxygen reduction reactions by electron injected into the conduction band of the host semiconductor. Semiconductors are stable under illumination, typically metal oxides, usually consist of the top of the valence band located at +3 eV or lower and most widely used as photocatalysts which can drive redox reactions under visible light (>400 nm) [4]…
