129 research outputs found

    Biodisinfection and Coagulant Properties of Mixed Garcinia kola and Carica papaya Seeds Extract for Water Treatment

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    Garcinia kola (Heckel) and Carica papaya (Linn.) seeds from ripe fruits were investigated for their disinfection and coagulation activity in water. The phytochemical analysis indicated the presence of alkaloid, saponins, flavonoid and tannins in both seeds. Physicochemical analysis of the water samples was determined before and after treatment with seed solutions. Results showed that mixed Garcinia kola and Carica papaya extracts had no significant effect (P > .05) on temperature, pH, conductivity and chloride but significantly reduced (P = .05) TDS, BOD, nitrate, nitrite and turbidity. The coagulation and antimicrobial efficiency of mixed Garcinia kola Heckel and Carica papaya seed solution at different concentrations on turbid surface water (collected from Ogbor Hill River in Aba) were studied and compared. Microbial reduction for mixed extract of Garcinia kola and Carica papaya solution showed antimicrobial efficiency of 41.67 – 83.33% for Total coliform, 47.85 – 60.89% for E. coli, 12.87-83.33% for Fecal streptococcus, 40.46 – 83.33% for staphylococcus Aureus and 50.43 – 74.36% for Total heterotrophic bacteria at different concentration. Mixed Garcinia kola and Carica papaya seed solution reduced the turbidity perfectly at the optimum doze of 3% at which 67.83% turbidity was removed by mixed solution. Garcina kola and Carica papaya seeds are non toxic and do not significantly affect the pH and conductivity of the treated water. So, as natural coagulants, both seeds may be potentially viable for treating water

    SLUDGE DEWATERING SUBJECTED TO CONSTANT VACUUM PRESSURE: A MODELLING APPROACH

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    Sludge is often generated from the treatment of wastewater and it is essential to reduce its volume before disposal into the environment through dewatering. This helps to reduce the cost of final sludge disposal. This study was therefore aimed at developing a model for the draining time of sludge through the application of vacuum pressure. A vacuum filtration experiment was performed on sewage sludge collected from the wastewater treatment plant situated at the University of Nigeria, Nsukka. The sludge sample was poured into Buchner funnel apparatus and the volume of the filtrate collected was noted at a certain time interval until the end of the experiment. The specific resistance values were obtained using the newly derived-, modified-, and Carman’s-equation, respectively. A comparative study was carried out on the three values obtained and the results showed that the newly derived equation gave the best result. Overall, the newly derived equation demonstrated conformity with Carman’s equation and can be used for sludge dewatering investigation. This paper covers a relevant subject within the field of waste treatment processes, namely the dewatering of sludge from wastewater treatment system and on a large scale, can aid in producing cost effective mechanism that makes it more possible for developing nations to incorporate adequate and effective sanitation

    Toxicity, Growth And Survival Of Clarias Gariepinus Juveniles Exposed To Different Concentrations Of Crude Oil Fractions-Polluted Water

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    Studies were carried out on the toxicity, growth and survival of Clarias gariepinus juveniles exposed to different concentrations of oil-polluted water. Thirty-nine aerated aquaria (60 × 30 × 30 cm3), arranged in a 4 × 3 Complete Randomized Block Design were used for the study. Three oil types: the Bonny light crude oil (BLCO), the premium motor spirit (PMS) and kerosene (DPK) at oilconcentrations of 1.00, 1.50, 2.00 and2.50 ml L -1 were used in triplicates of 5 ml to contaminate 15L of dechlorinated tap water and 20 fingerlings o Clarias gariepinus (22 ± 0.24 g) exposed to it. A control treatment (0.00 ml L-1) of non-oil contamination was aso used in riplicates. A 96-hour toxicity phase in the oil-polluted water preceded a 42 days recovery phase. 38% crude proein dietwas fed to fish during exposure and recovery phases at 3% and 5% body weight per day respectively. Water temperature, pH, fish mortality and normalized biomass index (NBI) of each aquarium were monitored. The total organic nitrogen, soluble organic nitrogen and colloidal organic nitrogen in addition to soluble and adsorbed ammonia in the aquaria water and sediments were analyzed using standard methods. Results showed that the water temperature was 26 ± 2.04° C, pH was 6.50 ± 0.30 and fortnighty eed intake of fish increased between days 14 and 42. This increase, which corresponded wth the increase in the fortnightly weight gain, could be attributed to the reduction of stress caused during the 96-h toxicity phase. The increase in the soluble ammonium and the exchangeable ammonium concentrations o water correlated with the increase inthe concentrations (1.50 – 2.50 ml L-1) ofBLCO, PMS and DPK. Percent mortality of fsh reduced between days 14 and 42 irrespective o oil treatment while fish exposed to the control treatment had lower percent mortality than those exposed to the oil treatments. This trend was corroborated by the relatively higher NBI for the control during the exposure (-0.02) and recovery{0.08 (14 days), 0.08 (38 days) and 0.21 (42 days)} periods than those of oi treatments (-49.64 to-0.10). Keywords: Clarias gariepinus, Toxicity, Soluble ammonium, Feed intake, Weight gainAnimal Research International Vol. 3 (2) 2006 pp. 466-47

    Phytochemical Composition, Antioxidant and Antimicrobial Potentials of some Indigenous Plants in Umudike, Abia State, Nigeria

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    Twenty four ethanol leaf and stem bark extracts of 17 indigenous plants were examined for their phytochemical composition, antimicrobial and antioxidant properties. Phytochemical compositions were analysed with GC-MS while antimicrobial activities on Staphylococcus aureus and Pseudomonas aeruginosa were investigated by the agar well diffusion method. The antioxidant activities were determined with Ferric reducing antioxidant power (FRAP), total phenolic content (TPC) and 2, 2,-dihenyl-1-picryhydazyl (DPPH) radical scavenging assays. The antibacterial activity was more towards the gram positive S. aureus than the gram negative P. aeruginosa for all the plant extracts.  A wide range of phenolic concentrations among the aqueous plant extracts which varied from 28.04 to 500.26mg GAE per gram were observed.  Inhibition percentages of DPPH ranged from 19.13 to 95.77% showing effectiveness in radical scavenging. GC-MS characterization of the plant extracts showed a total of 18 components including alkaloids, flavonoids, phenols, saponins, terpenoids, steroids and glycosides. Irvingia gabonensis leaf (IGL) extract and Tamarind stem bark (TSB) exhibited excellent ferric reducing abilities of 2.11 and 1.56 respectively while Voucanga Africana leaf (VCA) extract indicated the lowest ferric reducing power of 0.50. Extracts of IGL and TSB exhibited the highest antioxidant capacities and therefore could be the main sources of natural antioxidant. An important relationship between total phenolic content was observed showing that the major contributor to the antioxidant properties were phenolic compounds

    Stroke prevalence amongst sickle cell disease patients in Nigeria: a multi-centre study

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    Background: Stroke is a life-changing, debilitating complication of sickle cell disease (SCD). Previous studies had recorded high stroke prevalence amongst this group of patients. Nigeria has a large population of people affected by this condition and this study aims to assess the stroke prevalence in this large population.Methodology: Stroke prevalence data from 14 physicians working in 11 tertiary health centres across the country was collated by doctors using the sickle cell registers and patient case notes. This data was then collated and used to obtain the overall stroke prevalence in adult and children.Results: The stroke prevalence in sickle cell disease patients in Nigeria was observed to be 12.4 per 1000 patients. Prevalence in the adult patients was 17.7 per 1000 patients and 7.4 per 1000 patients in children. Twenty three percent of the affected patients had more than stroke episode.Conclusion: The stroke prevalence in Nigeria is lower than previously recorded rates and further studies will be required to investigate other factors which may play a role.Keywords: sickle cell, stroke, Nigeria, prevalenc

    CO2 dissolution and design aspects of a multiorifice oscillatory baffled column

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    Dissolution of CO2 in water was studied for a batch vertical multiorifice baffled column (MOBC) with varying orifice diameters (d0) of 6.4-30 mm and baffle open area (α) of 15-42%. Bubble size distributions (BSDs) and the overall volumetric CO2 mass transfer coefficient (KLa) were experimentally evaluated for very low superficial gas velocities, UG of 0.12-0.81 mm s-1, using 5% v/v CO2 in the inlet gas stream at a range of fluid oscillations (f = 0-10 Hz and x0 = 0-10 mm). Remarkably, baffles presenting large do = 30 mm and α = 36%, therefore in the range typically found for single-orifice oscillatory baffled columns, were outperformed with respect to BSD control and CO2 dissolution by the other baffle designs or the same aerated column operating without baffles or fluid oscillations. Flow visualization and bubble tracking experiments also presented in this study established that a small do of 10.5 mm combined with a small value of α = 15% generates sufficient, strong eddy mixing capable of generating and trapping an extremely large fraction of microbubbles in the MOBC. This resulted in increased interfacial area yielding KLa values up to 65 ± 12 h-1 in the range of the UG tested, representing up to 3-fold increase in the rate of CO2 dissolution when compared to the unbaffled, steady column. In addition, a modi fied oscillatory Reynolds number, Reâ€Čo and Strouhal number, St' were presented to assist on the design and scale-up of gas-liquid systems based on multiorifice oscillatory ba ffled columns. This work is relevant to gas-liquid or multiphase chemical and biological systems relying on efficient dissolution of gaseous compounds into a liquid medium.BBSRC -European Commissio

    Variations in the prevalence of point (pre)hypertension in a Nigerian school-going adolescent population living in a semi-urban and an urban area

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    <p>Abstract</p> <p>Background</p> <p>Hypertension has been shown to start in early life and to track into adulthood. Detecting adolescents with hypertension and prehypertension will aid early intervention and reduce morbidity and mortality from the disorders. This study reports the point-prevalence of the two disorders in a semi-urban and an urban population of school-going adolescents in Nigeria.</p> <p>Methods</p> <p>A total of 843 adolescents from two places of domicile were studied. Their blood pressures and anthropometric indices were measured using standard protocol. Point-hypertension and point-prehypertension were defined with respect to each subject's gender, age and height. The prevalence of the disorders was calculated and reported age-wise and nutritional status-wise.</p> <p>Results</p> <p>The prevalence of point-prehypertension in the semi-urban area was 22.2% (20.7% for girls and 23.1% for boys) while it was 25.0% (21.8% for girls and 29.2% for boys) in the urban area. The prevalence of point-hypertension was 4.6% (4.1% for girls and 4.8% for boys) in the semi-urban area and 17.5% (18.0% for girls and 16.9% for boys) in the urban area. Point-prehypertension was not detected among the thin subjects of both places of domicile. The prevalence of point-prehypertension was similar in both the urban and semi-urban areas among the subjects who had normal BMI-for-age, and over-weight/obese subjects respectively. From the semi-urban to the urban area, the prevalence of point-hypertension increased approximately 3-folds among thin and normal BMI-for-age subjects, and 10-folds among overweight/obese subjects. Systolic hypertension was more preponderant in both the semi-urban and urban areas.</p> <p>Conclusions</p> <p>The prevalence of both disorders is considerably high in the studied populations. Urgent pediatric public health action is needed to address the situation.</p

    Life Cycle Management of Infrastructures

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    By definition, life cycle management (LCM) is a framework “of concepts, techniques, and procedures to address environmental, economic, technological, and social aspects of products and organizations in order to achieve continuous ‘sustainable’ improvement from a life cycle perspective” (Hunkeler et al.\ua02001). Thus, LCM theoretically integrates all sustainability dimensions, and strives to provide a holistic perspective. It also assists in the efficient and effective use of constrained natural and financial resources to reduce negative impacts on society (Sonnemann and Leeuw\ua02006; Adibi et al.\ua02015). The LCM of infrastructures is the adaptation of product life cycle management (PLM) as techniques to the design, construction, and management of infrastructures. Infrastructure life cycle management requires accurate and extensive information that might be generated through different kinds of intelligent and connected information workflows, such as building information modeling (BIM)
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