Asymmetric supercapacitor based on novel coal fly ash derived metal–organic frameworks as positive electrode and its derived carbon as negative electrode

Journal of Applied Electrochemistry - The paper presents a comparative study between aluminum fumarate metal–organic framework (Al-FumMOF) and a novel coal fly ash derived aluminum MOF...     

The use of bio-diesel based additive as rheology improver and pour point depressant of Nigerian waxy crude

The chemical method has proved to be the most effective mitigating method of wax deposition in petroleum system as it deals with the root cause of wax formation. Most of the commercial chemicals in the industry are very expensive and toxic. This paper aims the use of biodiesel based additives for improving the rheological behavior and pour points of waxy crude from Nigeria field. The biodiesels derived additives gave better performance than the commercial chemical and the seed oils as greatly improvement in rheology and pour point values of the waxy crude were observed     

An Engineering Failure Analysis of a Biological Treatment Plant in Nigeria

Waste stabilization ponds (WSP) have been found useful and applicable in most parts of the world. Their application has been found in the treatment of industrial, commercial, institutional, and domestic wastewaters. Failures of WSP have not been reported until recently. This then calls for engineering analysis of failed ponds to prevent the recurrence of these ugly events. This paper presents results of an engineering failure analysis conducted on a waste stabilization pond at Obafemi Awolowo University, Ile-Ife, Nigeria. The ponds receive wastewater from selected student halls and academic buildings by gravity as a result of the topography of the campus. The ponds were visited, and influent and effluent qualities of the ponds were determined. Adequacy of the design parameters and structural behavior were studied and compared with the standard code. The study revealed that some of the engineering parameters were higher than the upper limit recommended by the standard code. Solids had accumulated in the ponds, resulting in anaerobic conditions in the ponds, generating hydrogen sulfide and acids as end products. Production of these acids corroded the sewers, cracked some manholes, and dislocated pipes (sewers). Accumulation of solid also led to sludge formation and thus reduced effective depth, length, and breadth of the ponds and made detention time below the specified range in the standard environmental pollution control code. It was concluded that the failure of the ponds can be attributed to partial adherence to the standard code in terms of vegetation, flood control mechanism, high biochemical oxygen demand and suspended loadings, and flow rate, as well as to low detention; all originated from improper maintenance. I. A. Oke and J. O. Babatola were formerly at Department of Water Resources and Environmental Engineering, Ahmadu Bello University, Zaria.     

Failure Analysis of an Effluent Treatment Plant in an Oral Care Industry

Reports of environmental pollution by industries worldwide call for an urgent need to assess wastewater treatment facilities in various industries. This study presents an assessment of a wastewater treatment plant in an oral care (toothpaste) industry. The industry was visited, facilities for wastewater treatment were assessed (based only on efficacy to remove selected environmental and human’s health-related pollutants) and measurement of essential design parameters and facility characteristics were conducted. The study revealed that the averages of flow rate, biochemical oxygen demand at 5 days (BOD₅), chemical oxygen demand (COD), suspended solids (SS), iron concentration, and total solids (TS) in the influent wastewater into the plant were 4.96 ± 0.6 m³/d; 90 ± 5 mg/L; 224 ± 8 mg/L; 1266.78 ± 10.24 mg/L; 0.31 ± 0.11 mg/L, and 2198.65 ± 20.44 mg/L, respectively. Individual efficacies were as follows: 0.49, 0.28, and 0.38% for SS, TS, and calcium, respectively. The overall efficacy of the wastewater treatment facility was found to be 0.020% which was significantly lower than expected. This indicates that no treatment was conducted on the wastewater and that the wastewater is being discharged into the environment essentially untreated. Equalization time (t _eq) was found to be 2.0 h with equivalent equalized BOD₅ concentration of 90 ± 5 mg/L, while expected volume for the equalization tank is 1.5 m³. It was concluded that failure (lower overall efficacy) of the system can be attributed to lack of an equalization tank, inadequate treatment processes, and refusal to apply standardized engineering code and practices. Although such conditions are rare in developed nations, these results demonstrate the problems in pollution control in developing communities.     

A STUDY ON THE NIGERIAN FOOD INDUSTRY AND THE IMPACT OF TECHNOLOGICAL CHANGES ON THE SMALL-SCALE FOOD ENTERPRISES

Industrial processing of foods assists the nation to maintain a steady supply of food products. This study assessed some factors influencing the growth of the Nigerian food industry with the view to identify some technological changes within the small-scale food enterprises and their impact in the last ten years. Information on the Nigerian food industry was compiled from a secondary source while a survey of small-scale food enterprises was conducted in SouthWest Nigeria using a structured questionnaire and interviews.

Results showed that the number of food manufacturing companies (FMCs) increased over the years with the largest number of FMCs established in the 1980s. The range of products produced is still small, with several FMCs producing similar products. More than 50% of the FMCs in the country are located in the SouthWest, with Lagos State as the major host. About 91% of the FMCs are listed as private and 7.3% are publicly quoted. Indigenous entrepreneurs wholly own 56.9% of the FMCs. Percent local sourcing is high in the FMCs. Areas of technological changes include expanded capacity utilization, expansion of production lines and expanded market shares, which arose as a result of the active involvement of management in the production process, acquisition of new packaging systems, and participation of the work force in process improvement. The study identified the need to standardize locally fabricated equipment to facilitate ready production of spare parts. Recommendations were made on how to increase the financial base of the small-scale enterprises.     

Failure Analysis of a Dissolved Air Flotation Treatment Plant in a Dairy Industry

Environmental pollution in Nigeria presents an urgent need to assess wastewater treatment facilities in various industries. This article presents an assessment of dissolved air flotation (DAF) operation in a dairy industry. The industry was visited, wastewater treatment facilities were assessed (based only on efficacy to remove selected environmental health-related pollutants) and measurements of essential design and characterization parameters were taken. The study revealed that the averages of flow rate, biochemical oxygen demand at 5 days (BOD₅), chemical oxygen demand (COD), suspended solids (SS) and total solids (TS) of the influent wastewater into the plant (DAF) were 3.45 L/s, 1652.37, 3304.67, 2333.82, and 4396.10 mg/L compared to effluent quality of 560.37, 1127.33, 172.33, and 1866.67 mg/L for BOD₅, COD, SS, and TS, respectively. The pH of the wastewater is being adjusted by addition of lime before the effluent equalization tank and individual efficacies of the system were 66.09, 65.89, 65.89, 57.54, 8.68, and 94.49% for BOD₅, COD, SS, TS, DS, and total nitrogen, respectively, with overall efficacy of 38.10%. It was concluded that failure (lower overall efficacy) of the system can be attributed to setting of lime in the oversized equalization tank (50 m³ instead of 16.82 m³ per 8 h shift), the lack of application of standardized engineering code and practices (provision of underground tank in the process, lack of complete coagulation processes, coagulation and flocculation units), lack of adequate aeration unit and lack of reliable systems for automatically adjusting dosage of coagulant and flocculant. Although, DAF unit is the centerpiece of a DAF-based system design, there are several other supporting systems important to optimal DAF operation. These observations, coupled with the analysis in this report, demonstrate that the facilities necessary to minimize continuous environmental pollution are lacking. Pollution will become an increasing problem unless pollution preventing codes and standards are developed; incorporated into government regulations and the regulations are enforced.