Adsorptive approach on nepholometric study of paint effluent using Tympanotonos fuscatus extract

Adsorptive study of paint effluent coagulation using T. fuscatus coagulant (TFC) is investigated. Effects of pH, dose, time, and temperature were investigated. Functional group, crystalline, morphology and thermal characteristics of samples were determined. Equilibrium data were analysed by Langmuir, Freundlich, Temkin, Frumkin, and Dubinin-Radushkevich (D-R) isotherms. Kinetic data were fitted to reversible first order, pseudo-first-order, pseudo-second-order, Elovich, intra-particle diffusion and Boyd kinetic models. Process Gibbs free energy (∆G°), enthalpy (∆H°) and the entropy (∆S°) were evaluated. The process was best described by Langmuir isotherm (R2 > 0.99; X2 ˂ 0.6; SSE ˂ 0.7). Pseudo second order best fitted the kinetic data. The process was spontaneous, feasible and endothermic. 97% optimal removal was achieved at pH 5. Tympanotonos fuscatus extract has potential for application as an effective coagulant while showing significant component of adsorptive phenomenon KEY WORDS: Paint effluent, Coagulation/flocculation, Adsorption, Tympanotonos fuscatus Bull. Chem. Soc. Ethiop. 2016, 30(3), 377-390.DOI: http://dx.doi.org/10.4314/bcse.v30i3.

METHODS OF ASTM G16 AND CONFLICTS IN CORROSION TEST DATA: CASE STUDY OF NANO2 EFFECTIVENESS ON STEEL-REBAR CORROSION

In this paper, applications of the methods of ASTM G16 for addressing inherent conflicts in laboratory measurements of corrosion test data were studied, using the inhibiting effect of NaNO2 on the corrosion of concrete steel-rebar for the case study. For this, electrochemical monitoring techniques were employed for studying effectiveness of different concentrations of NaNO2 admixture in replicated concrete samples immersed in NaCl and in H2SO4 media for an experimental period of sixty-eight days. The corrosion test data from this experimental setup were subjected to the probability density fittings of the Normal and the Weibull functions as well as to significance testing methods of ASTM G16-99 R04 specifications. Results identified 10g (0.1208M) NaNO2 admixture with optimal inhibition efficiency model, η = 88.38±4.62%, in the saline/marine simulating environment and the 8 g (0.0966M) NaNO2 admixture with optimum effectiveness, η = 13.51±83.48%, in the acidic environment. The techniques of ASTM G16 adequately identified and addressed conflicting effectiveness from the test data of NaNO2 admixtures in the studied test environments

A Review of Environmental Implications of Dredging Activities

Dredging is a global anthropogenic excavation activity of removing sediments from water bodies and depositing it elsewhere. It is a mixed blessing as it has both beneficial and adverse impacts. This paper is on a review of environmental implications of dredging. The objective of the paper is to review previous works by researchers on the environmental consequences of dredging. The method used is a review of academic/journal articles, internet materials, conference / workshop papers, textbooks, bulletins and publicly available materials on dredging activities. The results of the study revealed that previous authors whose works were reviewed have a convergent view that apart from the beneficial impacts of dredging (e.g. keeping waterways navigable, flood and storm protection and provision of materials for road construction and building), it has lots of adverse environmental impacts, including environmental pollution, erosion, widespread hydrological changes, reduction in the population of aquatic lives like destruction of fish spawning grounds and benthic organisms and resuspension of particulate matter column that has elevated levels of lead, copper, zinc and nickel in Phytoplankton. Recommendations of the study include: (1) establishment of environmental legislations and regulations for dredging operation; (2) use of green technology in dredging activities to minimize suspension of sediments and contamination/pollution of dredging environments; and (3) creation of awareness among dredging contractors, regulators and marine communities where dredging take place on the economic and ecological values of the marine ecosystems that are usually very sensitive, fragile and productive

This thing called communitarianism: A critical review of Matolino's Personhood in African Philosophy

The subject of personal identity has received substantial treatment in contemporary African philosophy. Importantly, the dominant approach to personal identity is communitarian. Bernard Matolino's new book Personhood in African Philosophy enters into this discussion by way of contesting some of the assumptions underlying communitarian approaches. His own critical assessment leads him to what I believe is an unprecedented objection in the literature; the conclusion that communitarian philosophers are involved in a category mistake when framing the question and articulating the notion of personhood. I intend to present a brief summary of the chapters of the book and reflect on some of the main philosophical issues that the book provokes, noting what I take to be refreshing insights that Matolino brings to the discussion while also engaging critically with the ones I find most contentious. In particular, I briefly assess Matolino's implicit suggestion that an Akan inspired quasi-physicalist account of mind avoids the mind-body interaction problem; I object to the category mistake charge on behalf of communitarians; and lastly, I raise questions about, and propose ways Matolino can refine, his proposal concerning a new way of thinking about personhood, which goes under the rubric of Limited Communitarianism.IS

Life (and limb) in the fast-lane:Disposable people as infrastructure in Kampala’s boda boda industry

Motorcycle taxis, dubbed boda bodas, constitute a vital aspect of Kampala’s transportation infrastructure, yet the industry is perpetually precarious, threatened with wholesale eviction. Moreover, drivers’ lives and bodies are continually put at risk by the city’s traffic. Through a relational approach to ontology, this article asks how the boda boda industry comes into being and endures, what forms of vulnerability it entails, and what experiences, relations, and forms of urban life it produces. It argues that three forms disposability structure and arise from the industry – structural unemployment, embodied vulnerability, and infrastructural displacement. Infrastructural violence, it is argued, must be considered when describing and theorizing people as infrastructure. The article examines how boda boda drivers’ shared condition of insecurity and disposability generates intense forms of sociality, solidarity, mutual obligation, recognition, and urban vitality

Technologies for removing pharmaceuticals and personal care products (PPCPs) from aqueous solutions: Recent advances, performances, challenges and recommendations for improvements

In recent years, the removal of pharmaceutical and personal care products (PPCPs) from aqueous solutions has been gaining a lot of attention from researchers throughout the world. This is particularly due to the concern about their potential hazards and toxicities, as they are classified as emerging contaminants. Thus, there is an increasing need to investigate removal technologies for PPCPs at a deeper and more holistic level. This review aims to provide the latest developments in removal technologies for PPCPs. It first succinctly describes the types, characteristics, and hazards of PPCPs on the environment and human health. It then comprehensively covers a wide range of technologies for removing PPCPs from aqueous solutions, comprising the adsorption process (using carbon-based adsorbents, plant biomasses, clay and clay minerals, silica-based adsorbents, zeolite-based adsorbents, polymers and resins, and hybrid adsorbents), advanced oxidation processes (AOPs) (photocatalysis, Fenton or photo-Fenton or electro-Fenton, ozonation, ultrasonication, electrochemical oxidation, persulfate oxidation), membrane separation processes (ultrafiltration, nanofiltration, reverse osmosis), biodegradation processes (bacteria, fungi, and algae), and hybrid treatment (adsorption-AOP, AOP-membrane, membrane-biodegradation, and others). According to the specific experimental conditions, the reported removal efficiencies for adsorption, AOPs, membrane processes, biodegradation processes and hybrid treatment were 40–100%, 40–100%, 3–100%, 14–100% and 5–100%, respectively. This review paper also highlights the challenges in this field of research, particularly incomplete removal of certain PPCPs, high costs of some treatment technologies and generally insufficient understanding on the removal kinetics and mechanisms of PPCPs. This review offers recommendations for future works to further advance the technical performances to eventually realize the wider application of these technologies at the industrial scale