Municipal wastewater management using Vetiveria zizanioides planted in vertical flow constructed wetland

This study investigated wastewater management using Vetiveria zizanioides planted in vertical flow constructed wetland (VFCW). Wastewater from the grit removal chamber and the primary sedimentation tank of Daspoort Wastewater Treatment Works was fed into six-pilot VFCW consisting of 1000-L plastic tanks having 500-mm-deep, 10–15-mm-diameter granite substrate planted with V. zizanioides. Irrigation of macrophytes using effluent from the grit removal chamber and primary sedimentation tanks was done after 3 months of planting and the VFCW monitored. Wastewater samples were collected and analysed using standard procedures. The pollution parameters of the initial sample were total alkalinity 297 ± 27.3 mg/L; COD 627 ± 149.0 mg/L; EC 82.53 ± 5.4 ms/m; free and saline ammonia 36.02 ± 4.1 mg/L, nitrate/nitrite 0.09 ± 0.1 mg/L; pH 7.66 ± 0.4; phosphate 3.07 ± 0.3 mg/L, sulphate 44.57 ± 3.1 mg/L; TDS 551 ± 37.8; TSS 319 ± 34.2 mg/L; and TKN 41 ± 6 mg/L. Percentage removal of 89.57, 98.34% TSS; 98.95, 98.62 free and saline ammonia; 89.87, 91.44% TKN; and 80.65, 58.02% COD for screen and settled wastewater, respectively, was obtained from the VFCW. VFCW using locally available V. zizanioides is a viable alternative for municipal wastewater treatment

Appraisal of access to safe drinking water in southwest Nigeria

The importance of developing effective water supply services is universally recognised as a basis for improving the overall health of the population. This study ascertained the quality of water supplied by a water treatment scheme in southwest Nigeria. One hundred and twelve samples were collected during the wet and dry seasons. Tests on physico-chemical and bacteriological parameters were conducted. Statistical analysis of variance was carried out on the results of the test. The effectiveness of the treatment processes on the parameters considered showed that the aeration, sedimentation and filtration processes were 70.13% effective in colour removal; sedimentation and filtration processes were 94.78% effective in turbidity removal; sedimentation and filtration process were 28.84% effective in the removal of total suspended solids (TSS) and 9.88% effective in the removal of total solids (TS); the disinfection and filtration processes were 100% effective in bacterial and coliform removal. The treatment system was found to be 71.38% effective in pollutant removal

Municipal wastewater treatment using sequential activated sludge reactor and vegetated submerged bed constructed wetland planted with Vetiveria zizanioides

This study investigated a sequential system consisting of Biological Nutrient Removal Activated Sludge(BNRAS) and Vegetated Submerged Bed Constructed Wetlands (VSBCW). The BNRAS/VSBCW combination removing pollutants from municipal wastewater in a developing country was examined. Wastewater from the anaerobic, anoxic and aerobic zones of the BNRAS was fed into 12 pilot VSBCW consisting of 1000 L plastic tanks having 500 mm deep 10–15 mm diameter granite substrate planted with Vetiveria Zizanioides. Irrigation of macrophytes using effluent from the BNRAS was done after 3 months of planting and the VSBCW effluent analyzed. Wastewater samples were collected and analyzed using standard procedures. Percentage removal of 96.6, 96.93, and 97.21% of COD; 33.33, 85.71, and 92.48% of Nitrate/Nitrite;53.51, 46.45, and 88.78% of Sulphate; and 98.34, 99.72, and 99.6% of TSS were obtained from the anaerobic, anoxic and aerobic zones respectively. Removal efficiency from the anaerobic zone effluent was highest during the study period. VSBCW using locally available macrophytes V. Zizanioides in combination with BNRAS was found efficient in municipal wastewater treatment

Plastic waste as strength modifiers in asphalt for a sustainable environment

This research took the form of an investigation into the applicability of polyethylene terephthalate (PET) as strength modifiers in asphalt road construction. Samples of thoroughly washed, naturally dried and shredded PET wastes were collected. The optimum binder content (OBC) of the unmodified asphalt mix was determined. The bitumen used for the control mix was replaced with PET waste in 1, 3 and 5% proportions. Another sample was prepared with the addition of 1, 3 and 5% of PET waste while the OBC was fixed. The samples were subjected to Marshall Stability (MS) and Marshall Flow (MF) tests. Bulk density (BD), void in total mix (VTM), and void filled with bitumen (VFB) were determined. The results were compared with standards. The PET content obtained that conforms to the specification in AASHTO, ASTM and Nigeria Federal Ministry of Works standards was found to be 1% addition to OBC by weight of aggregate. This percentage PET content was 15% by weight of bitumen with BD, VTM, VFB, MF and MS being 2.38 kg/m3, 3.33%, 82.20%, 4.00 mm and 17.01 kN, respectively. The 1% PET modified asphalt was found to be useful for pavement construction and reduces the quantity of plastic waste in our environment

An Assessment of Water Related Diseases in a Nigerian Community

Information on the general health problems in Ota was provided while the ailments that are directly related to water were highlighted and discussed. The information was gathered by questionnaire application, using non-quota sampling technique. The target respondents were health care workers such as doctors, nurses and pharmacists who work in hospitals and primary health care centers situated in the municipality. It was observed that out of the top seven diseases that are most frequently reported in Ota, five were water related. These diseases include malaria, typhoid, vital organ failure, cholera and skin disease. Reasons for the high level of water related ailments were explained by poor level of supply of potable water to the municipality, as well as poor sanitation practices by the residents

Causes, Impact and Management of Electronic Wastes: Case Study of Some Nigerian Communities.

Electronic waste (E-waste) is a relatively new and emerging municipal waste in Nigeria. As much as 400, 000 units of used electronic equipment arrive through the Lagos port into Nigeria each month. A large percentage of these imported equipment are completely unserviceable, thus contributing to waste load in the country. E-wastes are leading sources of heavy metal contamination in the environment when improperly managed. The current study examines the reasons for the upsurge in demand for electronics in waste. Information regarding factors that contribute to the generation of e-wastes was gathered through the administration of a structured questionnaire to sections of Ogun State, Nigeria. Findings from the study show that young people between the ages of 15 - 35 are responsible for the highest demand for electronics in the country. It was also shown that the national policy on e-wastes management (especially with respect to enforcement), is still in its formative stages and that public health is highly vulnerable to the effects of e-wastes

Analysis of auto-purification response of the Apies River, Gauteng, South Africa, to treated wastewater effluent

The assimilative capacity of water bodies is an important factor in the integrated management of surface water resources. The current study examined the auto-recovery processes of the Apies River from wastewater discharged into it from a municipal wastewater treatment facility, using a series of equations, including the modified Streeter-Phelps equation. Field data obtained include dissolved oxygen (DO), temperature, stream velocity, depth, and width. Water samples were also obtained at 10 sampling stations for the determination of biochemical oxygen demand (BOD) using standard methods. It was observed that the DO and BOD level (5.59 mg/L and 8.5 mg/L respectively) of the effluent from the wastewater treatment facility indicated better water quality than the Apies River background DO level (5.42 mg/L) and BOD level (13 mg/L). Also, at 270 m downstream of the effluent discharge point, another effluent stream (Skinnerspruit) adversely impacted on the Apies River with DO and BOD levels of 6.5 mg/L and 9.0 mg/L, respectively, compared to the Apies River background values of 6.81 mg/L and 8.0 mg/L, respectively. The stream, however, recovered well from both the background and imposed pollution sources as it had a computed positive auto-recovery factor of 1.74. Furthermore, the measured DO deficit was plotted against predicted DO deficit. The plot revealed a close match between the measured and predicted DO deficit, indicating that the model could be used for predicting DO deficit along other segments of the river. To further improve on the natural auto-recovery processes of the Apies River, it was recommended that flow along the Skinnerspruit should be enhanced by clearing the observed aquatic plants growing within the channel. Also, suspected pollution activities taking place further upstream on the Apies River should be investigated and appropriately addressed

A Model Selection Procedure for Stream Re-Aeration Coefficient Modelling

Model selection is finding wide applications in a lot of modelling and environmental problems. However, applications of model selection to re-aeration coefficient studies are still limited. The current study explores the use of model selection in re-aeration coefficient studies by combining several suggestions from numerous authors on the interpretation of data regarding re-aeration coefficient modelling. The model selection procedure applied in this research made use of Akaike information criteria, measures of agreement such as percent bias (PBIAS), Nash-Sutcliffe Efficiency (NSE) and root mean square error (RMSE) observation Standard deviation Ratio (RSR) and gragh analysis in selecting the best performing model. An algorithm prescribing a generic model selection procedure was also provided. Out of ten candidates models used in this study, the O’Connor and Dobbins (1958) model emerged as the top performing model in its application to data collected from River Atuwara in Nigeria. The suggested process could save software and model developers lots of time and resources, which would otherwise be spent in investigating and developing new models. The procedure is also ideal in selecting a model in situations where there is no overwhelming support for any particular model by observed data

Subjective Evaluation of Life Satisfaction by community-dwelling Spinal Cord Injury Patients Managed at the University College Hospital, Ibadan

Background: Life satisfaction in Spinal Cord Injury (SCI) population is influenced by the ability to perform social roles and engage in activities. Investigations on the psychosocial aspects of SCI in Nigeria have concentrated on the objective dimensions, while much has not been documented, qualitatively, on life satisfaction among the SCI survivors in our setting. The research focused on the subjective evaluation of well-being related to social role performance among community-dwelling adults with SCI managed at the University College Hospital Ibadan, Nigeria.Methods: The study design is descriptive and qualitative data collection was utilized. Seventeen SCI patients who had been discharged home were purposively selected and interviewed via telephone. The domains of life evaluated included sexual life, marital life, and general life satisfaction. These were assessed with an interview guide intended for this purpose. Data were thematically content analysed.Results: Some participants could return to employment and perform occupational roles. The participants described their life as dissatisfactory. Dissatisfaction was reported with sexual and marital life and social interaction after SCI. Family role performance was likewise dissatisfactory. The participants’ dissatisfaction with life post-SCI was largely influenced by their internalization and interpretation of the inability to function in areas of life they perceived important.Conclusion: The subjective evaluation of life reported by persons living with permanent SCI suggests that they require more support from their families, healthcare providers and the community at large. Additionally, their psychosocial needs deserve constant monitoring by the significant others and healthcare providers in order to provide timely countermeasures. Keywords: Life Satisfaction; Social Role; Spinal Cord Injury; Subjective Evaluation; Nigeri

EVALUATION OF TWO-STAGE SUBSURFACE FLOW CONSTRUCTED WETLANDS FOR ABATTOIR WASTEWATER MANAGEMENT

Abattoir wastewater is high in organic content, the waste recovery and treatment facility is expensive and this results in indiscriminate dumping into streams without adequate treatment. The effectiveness of using a two-stage subsurface flow constructed wetland to treat abattoir effluent was examined in this study. Diluted abattoir wastewater from Lafenwa Abattoir, Abeokuta, Ogun State, Nigeria was fed into a two-stage Vegetated Subsurface Bed Constructed Wetlands (VSBCW). The VSBCW consisted of 500 mm deep 10-15 mm diameter granite with 150 mm thick overlay of well graded sand planted with locally available Vetiveria nigritana. Grab samples were collected at selected points along Ogun river and measurement of physico-chemical parameters such as: Chemical Oxygen Demand (COD), Biochemical Oxygen Demand (BOD5), Electrical Conductivity (EC), Total Dissolved Solids (TDS) and Total Suspended Solid (TSS) of the influent and effluent from the VSBCW were carried out. Irrigation with water and diluted abattoir wastewater to examine the variation in plant growth rate was also investigated. The results revealed a pollution load reduction as the wastewater moves away from the discharge point but inadequate to meet the FEPA (1991) standard for wastewater discharge into rivers. The VSBCW was observed to reduce the concentration of BOD5, COD, EC, TDS and TSS in the abattoir wastewater by 88.71, 87.28, 45.72, 56.89 and 72.27 % respectively. The growth rate of the V. nigritana reduced by 1.9% when irrigated with abattoir wastewater. The study revealed that locally available V. nigritana in VSBCW is effective in abattoir wastewater treatment and could be use to curtail the pollution caused by discharge of untreated wastewater into rivers.     &nbsp