Thermo-economic and Environmental Assessment of Cement Production Plant

In this paper, the thermodynamic, economic and enviromental analyses of a cement plant are made using the first and second law of thermodynamics based on actual operational data. The thermo and economic calculations provide information about the cost formation and the interactions among the cement plant components. The enviromental analysis quantifies the emission and provides alternative ways of operating environmentally friendly cement production plant Keywords: : Cement, Economic, Environment, Exergy and Thermodynamic

Environmental Pollution from Road Transport System in Ogbomosoland, Southwestern Nigeria

Environmental pollutions from road transport system in Nigeria poses serious health hazards to the ecosystem because of presence of heavy metals and other pollutants. There are researches on assessment of heavy metals contamination of road side soils but most of them investigated the concentration of the heavy metals at the edge of the road pavements but did not considered the concentration at various distances away from the edge of the road pavement. This research therefore focussed on the investigation of the concentration of the contaminants at the edge of the road and at various distances away from the road pavement. A total of 225 soil samples were collected at three sampling depths (0, 10 and 20cm) using three sampling distances of 0.2, 1.5 and 3.0m from Federal, State and Local roads. The soil samples were digested using perchloric acid and trioxonitrate (v) acid and the resulting filterate was analysed using Atomic absorption spectrophotometer for concentrations of Lead (Pb), Copper (Cu), Zinc (Zn), Nickel (Ni) and Cadmium (Cd) at each road. The heavy metals concentration at depth 0cm and distance 0.2m show that the  Federal roads had the highest mean concentration of 154.67, 49.43, 124.71, 27.40 and 2.19µg/g for Pb, Cu, Zn, Ni and Cd respectively and the least being Local roads (110.60, 35.57, 104.26, 23.99 and 1.12µg/g). The mean heavy metals concentrations decreased with increasing soil depths and sampling distance for Federal, State and Local roads. Some of the heavy metals concentrations were above the permissible limit (Canadian Council of Ministers of the Environment, 2004). The study revealed that there are heavy metals in the road-side soils and concentrations for some of the roads were found to be above the permissible limits and this possesses serious health challenges to people around the neighbourhood. The concentrations also decreased with increasing sampling depth and distance for all the roads. Keywords: Environmental Pollution, Heavy metals, Road-side Soils, Sampling depth and distanc

Problems of Teaching and Learning Science in Junior Secondary Schools in Nasarawa State, Nigeria

Both parents and state government have repeatedly expressed the need to trace out the causes for the good results the fact that the specific goals of every state in Nigeria is to produce qualified  students for admission into institution of higher learning both within and outside the country. It has been observed that students shy away from the study of science. This is a negative attitude that brought about poor performance of students in basic science subjects. It was as a result of this that prompted the research into the problems of teaching and learning science in junior secondary schools. The research aimed at identifying the problems and suggests solution to them. As a result of these, two research questions were raised. (1) What factors are responsible for the difficulty in the teaching and learning of basic science in secondary schools?   (2) What strategies could be adopted to enhance better teaching and learning of basic science in junior secondary schools? Some factors such as quality and quantity of teaching staff, attitude of students, physical facilities, parents and government were investigated. Two different questionnaires were administered to one hundred and fifty (150) science students and twenty (20) science teachers drawn from ten (10) secondary schools in Nasarawa State in order to collect data. In administering it, Likert rating scale was used and simple mean was used to analyzed it. Some of the findings are: (a) The teaching and learning environment is not conducive (b) The foundation of teachers in science subjects is poor (c) The Students have poor foundation in science.  Based on the findings, it was recommended that (1) For effective teaching and learning to take place, the government should send science teachers for training (2) It has become necessary for Government to provide the necessary infrastructures and facilities that will enhance teaching and learning of basic science in the junior secondary schools. Keywords: Science, Teaching, Learning, Performanc

Medication adherence in type 2 diabetes patients: study of patients in Alimosho General Hospital, Igando, Lagos, Nigeria.

Background: Poor adherence is an obstacle in therapeutic control of diabetes. Despite the advances in the treatment of diabetes mellitus over the years, diabetes places an immense burden on the individuals living with the condition, their families and the overall health care system.Objective: Evaluation of the impact of medication adherence on the clinical outcomes of type 2 diabetes patients at Alimosho general hospital, Igando Lagos state.Method: The medication adherence study was both descriptive (retrospective) and prospective. The retrospective study assessed the prevalence of medication non-adherence leading to poor glycemic control. This involved the review of case notes of one-hundred and fifty two randomly selected patients. Prospective study was done by counselling and educating the patients on medication adherence and assessing their medication adherence and the impact of medication adherence on glycemic control.Results: The proportions of females/males with type 2 DM was found to be 69% and 31% respectively. 51.32% of these patients viewed their medications to be unaffordable. 56.6% of the patient population were 61 years and above in age. There was a significant relationship between patient age, gender and adherence to medication. There was however no significant P ≥ 0.05 association between educational level and adherence. Health education and counselling resulted in adherence rate and clinical parameters improvements.Conclusion: Non-adherence is a major factor that could lead to morbidity and mortality in diabetic patients. The overall improvement in adherence rate of 86.8% was observed with a decline in non- adherence rate after interventions.Key words: Diabetes type 2, adherence, glycemic level, health education and counselling

Energy efficient control and optimisation techniques for distillation processes

PhD ThesisDistillation unit is one of the most energy intensive processes and is among the major CO2 emitter in the chemical and petrochemical industries. In the quest to reduce the energy consumption and hence the environmental implications of unutilised energy, there is a strong motivation for energy saving procedures for conventional columns. Several attempts have been made to redesign and heat integrate distillation column with the aim of reducing the energy consumption of the column. Most of these attempts often involve additional capital costs in implementing. Also a number of works on applying the second law of thermodynamics to distillation column are focused on quantifying the efficiency of the column. This research aims at developing techniques of increasing the energy efficiency of the distillation column with the application of second law using the tools of advanced control and optimisation. Rigorous model from the fundamental equations and data driven models using Artificial neural network (ANN) and numerical methods (PLS, PCR, MLR) of a number of distillation columns are developed. The data for the data driven models are generated from HYSYS simulation. This research presents techniques for selecting energy efficient control structure for distillation processes. Relative gain array (RGA) and relative exergy array (REA ) were used in the selection of appropriate distillation control structures. The viability of the selected control scheme in the steady state is further validated by the dynamic simulation in responses to various process disturbances and operating condition changes. The technique is demonstrated on two binary distillation systems. In addition, presented in this thesis is optimisation procedures based on second law analysis aimed at minimising the inefficiencies of the columns without compromising the qualities of the products. ANN and Bootstrap aggregated neural network (BANN) models of exergy efficiency were developed. BANN enhances model prediction accuracy and also provides model prediction confidence bounds. The objective of the optimisation is to maximise the exergy efficiency of the column. To improve the reliability of the optimisation strategy, a modified objective function incorporating model prediction confidence bounds was presented. Multiobjective optimisation was also explored. Product quality constraints introduce a measure of penalization on the optimisation result to give as close as possible to what obtains in reality. The optimisation strategies developed were applied to binary systems, multicomponents system, and crude distillation system. The crude distillation system was fully explored with emphasis on the preflash unit, atmospheric distillation system (ADU) and vacuum distillation system (VDU). This study shows that BANN models result in greater model accuracy and more robust models. The proposed ii techniques also significantly improve the second law efficiency of the system with an additional economic advantage. The method can aid in the operation and design of energy efficient column.Commonwealth scholarship commissio

Investigating the occurrence of E. coli O157:H7 in the final effluents of two wastewater treatment plants.

AIM: The final effluent of two wastewater plants located in the Eastern Cape of South Africa were tested for the presence of Enterohaemorrhagic Escherichia coli O157:H7 (E. coli O157:H7) isolates, and characteristics of the isolates obtained were determined. METHODS AND RESULTS: A total of 23 wastewater samples were collected from the treatment plants at the final effluent point after the disinfectant stages of wastewater processing. Altogether, 540 presumptive E. coli isolates were obtained by colony counting on the E. coli O157:H7 chromogenic agar base supplemented with cefixime tellurite and were sub-cultured onto sorbitol-MacConkey agar and tested for agglutination using the Prolex E. coli O157 latex test reagent kit. The results showed that the 149 suspected colonies from SMAC agar were all negative for the antisera. CONCLUSION: None of the isolates agglutinated with antisera against E. coli O157. Thus no presence of the bacteria can be confirmed from the treated effluents SIGNIFICANCE AND IMPACT OF STUDY: The likelihood of the receiving water body and the environment being contaminated with E. coli O157:H7 is therefore minimal

Incidence of human adenoviruses and Hepatitis A virus in the final effluent of selected wastewater treatment plants in Eastern Cape Province, South Africa

Municipal effluent constitutes a large reservoir of human enteric viruses and bacteria. Contemporary monitoring practices rely on indicator bacteria, and do not test for viruses. Different viruses, including Norwalk-like viruses, Hepatitis A virus (HAV), adenoviruses, and rotaviruses, are important agents of illnesses in humans. The burden of disease caused by adenoviruses manifests as pneumonia, bronchiolitis, otitis media, conjunctivitis, and tonsillitis, whereas HAV infection can manifest as acute inflammatory diseases of the liver, fever, anorexia, malaise, nausea, and abdominal discomfort, followed by jaundice and dark urine. The public health implications of these viruses depend upon the physiological status of the wastewater microbial community

Assessment of the Physicochemical Qualities and Prevalence of Escherichia coli and Vibrios in the Final Effluents of Two Wastewater Treatment Plants in South Africa: Ecological and Public Health Implications

The final effluents of two wastewater treatment plants (WWTPs) in the Eastern Cape Province of South Africa were evaluated for their physicochemical and microbiological qualities over a period of 12 months. The physicochemical parameters assessed ranged as follows both plants. The ranges of values for the physicochemical are: pH (3.9–8.6), total dissolved solids (86.50–336.3 mg/L), electrical conductivity (13.57–52.50 mS/m), temperature (13–28 °C), nitrate (0–21.73 mg/L), nitrite (0.01–0.60 mg/L), orthophosphate (1.29–20.57 mg/L), turbidity (4.02–43.20 NTU), free chlorine (0.05–7.18 mg/L), dissolve oxygen (3.91–9.60 mg/L), biochemical oxygen demand (0.1–9.0 mg/L) and chemical oxygen demand (4.67–211 mg/L). The microbiological assessment for both WWTPs revealed the presence of E. coli in counts ranging between 0 and 1.86 × 104 CFU/100 mL and Vibrio counts ranging between 0 and 9.93 × 103 CFU/100 mL. We conclude that these WWTPs are important point sources of pollution in surface water with potential public health and ecological risks