Biosorption of nickel (II) ion from synthetic wastewater on watermelon rind activated carbon using reponse surface methodology (RSM) optimization approach

The introduction of lethal heavy metals into the environment from industrial wastes is a major problem that needs immediate attention. In the present study the adsorption efficiency of nickel ions from a synthetic wastewater using watermelon rind activated carbon as a biosorbent is reported. Four basic process variables – initial Ni2+ concentration (5 – 100mg/l); pH (2 – 7); contact time (20 – 720 minutes) and adsorbent dosage (5 – 25g/l) were used for the investigation. Response surface (Box Behnken design expert 7.0®) methodology based on a design of experiment (DOE) that produced 29 batch experimental runs was used. The amount of Ni2+ adsorbed was optimized numerically to determine the optimum conditions for the adsorption process. The results of the study show that initial Ni2+ concentration of 100 mg/l; pH value of 6.69; 5g adsorbent dosage and 365.89 minutes contact time were the optimum process conditions for the removal of 18.43mg/g of Ni2+ representing 97% of the maximum predicted adsorption rate. It can be concluded therefore, that water melon rind activated carbon has high adsorption capacity and can be used effectively as adsorbent for the removal of nickel from nickel polluted waste and surface water.Keywords: Adsorption, nickel ion, optimization, response surface methodology, water melon rin

Aromatization of Propylene on Pt-Cu /?-Al2O3 Nano-Catalyst

Aromatization of propylene was carried out on Pt-Cu/ ?-Al2O3 bimetal catalyst at a temperature of 460 ± 60oC and the effectiveness of the catalyst was measured using the Gas to Liquid (GTL) product rate per single feed run. The observed mechanism was used to propose a kinetic that can be used to quantify the viability of the nano-catalyst presented here. From the kinetic analysis it was observed that adsorption of hexene-1 was responsible for isomerization reaction that produced methyl-cyclopentene. The methyl-cyclopentadiene served as electron pivotal at the catalyst centre where Pt-Cu/?-Al2O3 was responsible for ring opening and subsequent cyclic formation and isomerization that produced benzene the final product with an observed suppression of cracked products. Keywords: propylene, cyclopentene, nano-catalyst, methylcyclopentene, aromatizatio

Contamination of agricultural soils by selected heavy metals from municipal solid waste dumpsites-A case study of Oleh Town in Nigeria’s Niger Delta

The University town of Oleh in Nigeria‟s Niger Delta Area is one of the emerging urban cities in Nigeria currently facing waste disposal menace. In the present study, soil samples collected at three different distances (0, 5 and 20 meters) from four major dumpsites (DS 1 – DS 4) strategically located in the town were analyzed for Pb, Hg, Cd, Cr, Ni and Zn content.. The results of the analysis show heavy metal contamination of all the sites studied. Soil around DS 1, recorded the highest lead and zinc concentrations of 120 ± 5.21 mg/kg and 128.91 ± 0.38 mg/kg respectively compared to the control concentrations of 4.24 ± 0.07 mg/kg and 25.71 ± 0.82 mg/kg for the area. Samples from DS 2 and DS 3 have the highest nickel concentrations of 134 ± 0.5 mg/kg and 109.34 ± 4.80 mg/kg respectively while the control concentration for this metal is 12 ± 0.09 mg/kg for the area and the international allowable limit for the metal as endorsed by FEPA is 50 mg/kg

ADAPTATION OF NATURAL GAS FOR MOTOR FUELS IN NIGERIA TRANSPORT SYSTEM

In recent years, as a result of limiting reserve of crude oil and the clamour for the deregulation of the petroleum sector of the nation's economy, there is need to look beyond liquid fuel (gasoline, diesel) as vehicular fuels. The viability of adapting natural gas for motor fuels had been presented. Natural gas as automobile fuel has a multiple of advantages over liquid fuel. These include high octane number, less negative effects on engine parts, low toxicity of effluents. (i.e. low CO, NOX, and lead emissions.) Experiences of other countries that are presently using natural gas as automobile fuel are reviewed along with the efforts put in place by Nigeria through the Nigerian Gas Company (NGC) Limited to experiment the project. The need of government through the NGC to be fully involved in the planning and execution of a retrofit plan to optimize pipeline network and supply service of natural gas to refueling and refilling stations is also emphasized. The public on the other hand requires enlightenment on the need to convert their vehicles to gas/gasoline powered, and incentives given for patronizing natural gas filling stations. A cohesive interplay of both national and corporate interests in policy formulation and implementation will harness effective distribution and utilization of natural gas within the Nigeria socio-economic sector. Key words: Gas, Fuel, Automobile, Technology, Project. [Global Jnl Engineering Res. Vol.1(2) 2002: 81-88

ENERGY MANAGEMENT IN THE INDUSTRIAL SECTOR OF NIGERIAS ECONOMY

Effective use of local energy source by the industrial sector is of vital importance economically and environmentally. Strategies are suggested for better management of industrial energy consumption and use. Cogeneration, waste heat use, industrial integration are some strategies that can be employed to enhance effective energy use and minimize waste heat. Savings can be made by government on initial power generation costs by leveling out power consumption and reducing peak consumption rates. This the government can do by enforcing a timeofday tariff. Consumer awareness of the strategic importance of energy use can significantly contribute to encouraging industries to pursue energy saving policies. Key Words: Co-generation, integration, energy, discounted price, buffering [Global Jnl Engineering Res. Vol.1(1) 2002: 65-72

KINETIC MODELLING AND HALF LIFE STUDY OF ADSORPTIVE BIOREMEDIATION OF SOIL ARTIFICIALLY CONTAMINATED WITH BONNY LIGHT CRUDE OIL

In this study, comparative potential effects of commercial activated carbon (CAC) and plantain peel-derived biochar (PPBC) of different particle sizes and dosage to stimulate petroleum hydrocarbon biodegradation in soil were investigated. Microcosms containing soil were spiked with weathered Bonny light crude oil (WBLCO) (10% w/w) and amended with different particle sizes (0.02, 0.07 and 0.48 mm) and dosage (20, 30 and 40 g) of CAC and PPBC, respectively. The bioremediation experiments were carried out for a period of 28 days under laboratory conditions. The results showed that there was a positive relationship between the rate of petroleum hydrocarbons reduction and presence of the CAC and PPBC in crude oil contaminated soil microcosms. The WBLCO biodegradation data fitted well to the first-order kinetic model. The model revealed that WBLCO contaminated-soil microcosms amended with CAC and PPBC had higher biodegradation rate constants (k) as well as lower half-life times (t1/2) than unamended soil (natural attenuation) remediation system. The rate constants increased while half-life times decreased with decreased particle size and increased dosage of amendment agents. ANOVA statistical analysis revealed that WBLCO biodegradation in soil was significantly (p = 0.05) influenced by the addition of CAC and biochar amendment agents, respectively. However, Tukey’s post hoc test (at p = 0.05) showed that there was no significant difference in the bioremediation efficiency of CAC and PPBC. Thus, amendment of soils with biochar has the potential to be an inexpensive, efficient, environmentally friendly and relatively novel strategy to mitigate organic compound-contaminated soil

APPLICATION OF CASSAVA PEELS ACTIVATED CARBON IN THE TREATMENT OF OIL REFINERY WASTEWATER – A COMPARATIVE ANALYSIS

A comparative analysis of the efficiency of activated carbon produced from fermented cassava peels (CPB), unfermented cassava peels (CPA) and commercial grade activated carbon (CAC) in the treatment of refinery wastewater was carried out. CPB was found to be 8% and 18% more efficient when compared to CPA and CAC in the removal of COD, and 14% and 3% better than CAC and CPA respectively in the removal of BOD5. The removal efficiency of Pb2+ by CPB was 100% compared to 95% and 57% by CPA and CAC while 96% of phenol was removed by CPB against 93% and 83% by CPA and CAC respectively. This better performance of CPB over CPA and CAC is not unconnected with its higher pH resulting from the removal of cyanide from the peels during the fermentation process. However, despite the high phenol removal efficiency by CPB, the concentration of phenol in the treated effluent does not meet the environmental guidelines for disposal. It is therefore, recommended that a two-stage CPB adsorption column arranged in series is necessary to treat refinery wastewater efficiently if it is desired to totally remove phenol from the effluent or reduce the concentration to 0.005mg/l allowed by the Federal environmental protection agency (FEPA). The equilibrium adsorption test conducted showed that the Freundlich isotherm is a better fit for the adsorption of phenol by the three activated carbons with correlation coefficients (R2) of 0.9364, 0.9383 and 0.9541 for CAC, CPA and CPB respectively. CPB was found to be a better adsorbent as it has the highest adsorptive capacity as evidenced from its better Freundlich exponent

Investigation of the Nutrient Composition of Fluted Pumpkin (<i>Telfairia occidentalis</i>) under Herbicide Treatment

During the 2013 and 2014 harvest seasons, field and laboratory experiments were conducted in Nigeria’s inferred agroecological zone. The nutritive value of fluted pumpkin (Telfairia occidentalis) leaves was evaluated by measuring the levels of carbohydrate, protein, fat, ash, dietary fiber, and moisture content in Telfairia occidentalis using the standard analytical methods. The experiment was laid out in a randomized complete block design (RCBD) and repeated four times. Three separate applications of paraquat herbicide (non-selective) at rates of 100, 150, and 200 L ha−1 were applied to the treated plots. Comparative studies of the nutritive value of T. occidentalis were observed in the treatment and control plots. The effects of herbicides showed that the proximate composition of the T. occidentalis leaves of the treated plot was 70% carbohydrate, 29% protein, 1.8% fat, 1.7% dietary fiber, 7.9% ash, and 8.7% moisture. In contrast, the values of the control plots were 6.5% carbohydrate, 1.9% protein, 1.5% fat, 1.2% dietary fiber, 7.0% ash, and 7.9% moisture. The results show that paraquat herbicide spray increased moisture, protein, fat, carbohydrate, ash, and vegetable yields in the treated plot and that T. occidentalis leaves are rich in lipids, fiber, and protein. As a result, the control plot’s fiber, carbohydrate, protein, ash, and moisture content decreased drastically without using paraquat. These results demonstrate that herbicides can affect the nutritional yield of T. occidentalis by eliminating weeds alongside the main crops (T. occidentalis) in the agroecological zone of south-eastern Nigeria. Therefore, if consumed in sufficient quantities, the studied leafy vegetables will significantly contribute to the nutritional needs of human health and the Nigerian population’s food security