Optimization of process parameters for sorption of p-Nitrophenol from aqueous solution by hexadecyltrimethylammonium chloride-treated bentonite (HDTMA-bentonite)

Sorption of p-Nitrophenol from aqueous solution using hexadecyltrimethylammonium chloride treated bentonite (HDTMA-bentonite) clay was investigated using a batch system. The combined effect of four independent variables: contact time, pH, adsorbate concentration and solid:liquid ratio on the sorption process was studied and optimized using the Central Composite Design-Response Surface Methodology. The development of the experimental design as well as the interpretation of results was carried-out using the statistical software MINITAB 16 (Stasoft, USA). It was observed from this investigation that the percentage removal efficiency was influenced by process parameters in the following order: solution pH ˃ Adsorbate concentration ˃ solid:liquid ratio ˃ contact time. Optimum values for pH, adsorbate concentration, solid:liquid ratio and contact time were found to be 7.97, 2.01mg/dm3, 2.86 and 99 minutes respectively for the maximum p-nitrophenol removal (99.79%). It was also observed that both experimental and predicted values were in good agreement and the model developed was significant. These results indicate the suitability of HDTMA-bentonite for the removal of p-nitrophenol from aqueous solution

Chelating ligands: enhancers of quality and purity of biogas

The quality of biogas depends largely on the percentage of methane and hydrogen sulphide gas present. High concentration of hydrogen sulphide results in low quality biogas. This work employed the use of chelating ligands in scrubbing hydrogen sulphide gas while improving the yield of methane gas. Experimental analyses were carried out using Biogas 5000 analyser, Atomic Absorption Spectrophotometer and other classical analytical tools. Results from the analyses showed a 12 to 15 % improvement in the methane gas yield and reduction in the concentration of hydrogen sulphide gas from 80 to 30%. All digesters recorded pH within the optimum values. The cow dung (CD) digester shows significantly low volatile fatty acids concentrations which contributed to the increased methane gas yield. Trace metals like Iron, Cobalt and Nickel, found to be present within the digesters; reacted with the chelating ligands to form metal chelates which increased the bioavailability of essential nutrients; promoting the growth and stability of methanogens thus, improving methane production. The metal chelates equally undergoing a redox reaction with the hydrogen sulphide gas, produced elemental sulphur with the release of H+ ions; thereby reducing the concentration of hydrogen sulphide. Generally, addition of ligands to substrate digesters increased methane production and significantly decreased hydrogen sulphide concentration.Keywords: Biogas, Volatile fatty acids, Methane, Hydrogen sulphide and Ligand

Linear polarization studies of the corrosion inhibition of aluminium using leaves extract of Alcalypha wilkesiana

An electrochemical investigation was conducted to evaluate the corrosion behavior of Aluminum in 1M Hydrochloric acid medium. Corrosion currents were determined using the linear polarization technique. Tafel slopes, βa and βc were also determined by Tafel polarization measurements. The effect of Extracts of Alcalypha wilkesiana on the Aluminum corrosion behavior was observed in electrolyte solutions at room temperature. The results showed a lower corrosion rate (CR) in the Alcalypha wilkesiana solution (AS), having a CR of 14.26 mm/yr against that of the blank solution (BS) with a CR of 22.61 mm/yr. The calculated inhibition efficiency was 37 %

Evaluation of capsaicin content in parts of some peppers grown in Nigeria

The capsaicin content in parts (placenta, seeds and periderm) of some peppers grown in some parts of Nigeria was evaluated. Capsaicin was extracted from the pepper parts was carried-out via the solvent extraction technique using methanol. A Gas Chromatograph-Mass Spectrometer, (GCMS QP-2010, Shimadzu Analytical Instruments) was used for determination of capsaicin content. Capsaicin content was highest in the placenta, followed by the seeds for all the pepper samples utilized in the study. The outer flesh (periderm) had the lowest content of capsaicin. The capsaicin content of the placenta ranged from 1.1652±0.0002 in the Yellow pepper from Nsukka (Capsicum chinense) to 0.3226±0.0002mg/g in the “Atarugu” pepper (Capsicum annuum var) obtained from Zaria. The capsaicin content of the outer flesh ranged from 0.4619±0.0050 in the Yellow pepper from Nsukka (Capsicum chinense) to 0.0070±0.0002mg/g in the “Atarugu” pepper (Capsicum annuum var) obtained from Zaria. The parts of the yellow pepper (Capsicum chinense) had higher capsaicin content than the respective parts of the remaining peppers analyzed in the study. Also, the pepper parts of Capsicum chinense variety had higher capsaicin contents than those of Capsicum annuum, with parts of the large-fruited Capsicum annuum var having the least capsaicin content

Quality assessment of baby food produced from cereals enriched with date palm

The objectives of the study were to formulate a composite blend (weaning food) based on locally available cereals and legumes, to chemically evaluate their nutrient values, and compare with those of a proprietary formula. The study is part of the effort to provide home-based complementary (weaning) foods that can be more cost-effective to the low-income families. Composite blends were formulated based on protein basis of the food commodities used: millet, guinea corn, yellow corn, soybean, groundnut and date palm. Standard procedures of the Association of Official Analytical Chemists were used to determine the proximate chemical composition. Atomic absorption spectrophotometer and ion chromatographic analyzer were used to determine the mineral elements composition. The overall results indicated that crude protein, lipid, fibre, ash, moisture, energy and carbohydrate contents of the composite blend were either comparable or higher than values in the proprietary formula. The researchers believe that complementary foods formulated from locally available food commodities have great potential in providing nutritious foods that are practical, food-based approaches, aimed at combating the problem of malnutrition among infants and children in Nigeria in particular, and developing countries in general

Biodegradation of endosulfan by mixed bacteria culture strains of Pseudomonas aeruginosa and Staphylococcus aureus

Endosulfan is a synthetic cyclodiene non-systemic insecticide and acaricide with both contact and stomach activity. Microorganisms play a key role in removal of xenobiotics like endosulfan from the contaminanted sites because of their dynamic, complex, and complicated enzymatic systems which degrade these chemical. In this study, endosulfan was degraded by indigenous bacteria strains of Pseudomonas aeruginosa and Staphylococcus aureus. The biodegradation process was carried out according to the method established by Buff et al., 1992. The results obtained showed that the bacterial strains efficiently degraded endosulfan by consuming more than 90 % of 40 mg/l of the minimal media within 7 days of incubation. Maximum biodegration by these two selected bacterial stains was observed at an initial pH of 8.0 at an incubation temperature of 30 °C. The findings from present study suggest that these bacterial strains could be potentially promising as a low cost effective technology in the biodegradation of endosulfan from the environment.Keywords: Endosulfan, Microoganisms, Biodegradation, Contamination and Soi

Biosorption of Nickel (II) from aqueous solution onto activated carbon prepared from chicken feather

Industrial waste water is a potential threat to human health mainly because of the presence of nonbiodegradable, hazardous heavy metals. This research focuses on the use of Activated Carbon from Chicken Feathers (ACCF) in the removal of Ni (II) ions from aqueous solution. Fourier Transform Infrared (FTIR) analysis was carried out on ACCF to reveal the functional groups present which will aid adsorption. The optimization of factors such as initial metal ion concentration, pH, and contact time were investigated at ambient temperature. The optimum pH, initial metal ion concentration and contact time were therefore determined. The experimental data obtained for Ni2+ sorption were treated using pseudo first order and second order kinetic models. The adsorption behavior was found to follow pseudo second order kinetics. This study demonstrates the effectiveness of ACCF in the removal of Ni (II) ion from aqueous solution.Keywords: adsorption, chicken feather, kinetic

Determination of bacteria and trihalomethane compounds in sachet water commonly sold in Samaru, Zaria

Portable water is essential to humans and other forms of life. Poor treatment of drinking water results in the distribution of drinking water contaminated with bacteria and trihalomethane (THMs) compounds. Five brands of sachet drinking water were analyzed for coliform colony units and THM compounds concentration using Multiple Tube test and UV- spectrophotometer. The results showed the presence of Enterobacter which is a disease causing bacteria in all the water samples with W5 having the highest colony unit of 11. This was followed by W4 and W3 with five colony units and lastly W2 and W1 with less than two colonies. The concentrations of THMs were also determined with W5 having the highest concentration of 0.032 μg/cm3, followed by W2 with a concentration of 0.02 μg/cm3; W4 had a concentration of 0.011 μg/cm3, W1 a concentration of 0.01μg/cm3 and lastly, W3 having a concentration of 0.007 μg/cm3. All samples had THM compounds with concentrations above the national permissible limits. The presence of Enterobacter, a disease causing organism and the high concentration of THMs in the water samples, are a cause for concern as they pose as a risk to human health; indicating that the waters evaluated are not in any way fit for consumption.Keywords: Trihalomethanes, Coliforms, Pathogens, Sachet water, Bacteri

Biodegradation of Naphthalene using Pseudomonas putida and Bacillus subtilis Immobilized on Snail Shell

This study investigated snail shell as a carrier to immobilize Pseudomonas putida and Bacillus subtilis isolated from refinery effluent for the degradation of naphthalene in synthetic wastewater at various process conditions such as initial naphthalene concentration, pH, adsorbent dosage and ambient temperature of 30 oC in batch mode. The results showed that the adsorption and the biodegradation capacity increased with increase in naphthalene concentration, where 73.11%, 74.46% and 65.20% of the optimum concentration (50 mg/L) were removed by immobilized Pseudomonas putida, Bacillus subtilis, and snail shell respectively after 72 hours incubation. The optimal degradation occurred at the adsorbent dosage of 2 g at pH 9 and pH 7 for the adsorption and biodegradation respectively. The results were well fitted to both Langmuir and Freundlich models. Therefore, snail shell can be employed as a low-cost adsorbent and solid support matrix for immobilizing microorganisms in remediating hydrocarbon contaminants.Keywords: Biodegradation; Naphthalene; Immobilization; Snail shell

Adsorption and Biodegradation of 1-Methyl Naphthalene Using Immobilized Pseudomonas macerans and Bacillus subtilis on Burnt Kaolin

This work is aimed at assessing the effect of incorporating Pseudomonas macerans and Bacillus subtilis on burnt kaolin (BK) during the biodegradation of 1-methyl naphthalene. The biodegradation was monitored by determining the concentration of CO2 released. Immobilized Pseudomonas macerans on BK released CO2 in the range of 0.72 - 0.83 mg/L, while this was 0.68 - 0.78 mg/L with Bacillus subtilis; for the degradation alone the range was 0.39 - 0.46 mg/L after 72 h. Generally, the concentration of carbon (IV) oxide released by the immobilized Pseudomonas macerans was more than that by Bacillus subtilis. Therefore, immobilization using BK resulted to better removal of the organic pollutant. The FTIR indicated presence of new peaks within the regions 3272-3265cm-1 and 1647-1640cm-1 attributed to overlapping of hydroxyl (-OH) and carbonyl (C=O) stretching in carboxylic acid. The absorptions within 1114-1088 cm-1, and at 1408cm-1 are due to C-O stretching and O-H in plane bending of carboxylic acid respectively. The use of kaolin for environmental clean-up of organic pollutants will enhance the value chain of solid minerals in Nigeria