Removal of chromium and nickel ions from aqueous solution by adsorption on modified coconut husk

The study investigated the adsorption of Cr(VI) and Ni(II) on modified coconut husk (low cost adsorbent) for the remediation of Cr(VI) and Ni(II) from some synthetic industrial waste effluents. The coconut husk was modified by mixing with 0.1 M NaOH and HCl respectively. The effects of varying adsorbent loading, hydrogen ion concentration, contact time and temperature of adsorption were studied. Similar experiments were carried out using unmodified coconut husk, in order to compare the results obtained from the modification experiments. The result showed that the HCl modified adsorbent gave 96% ± 3.6 removal for Cr(VI) at a pH of 4.0 while about 99% ± 0.7 of Ni(II) was removed at a higher pH of 7.0. The unmodified adsorbent gave a 90% ± 8.8 adsorption for Cr(VI) and 97% ± 1.5 for Ni(II) respectively. However, the NaOH modified adsorbent gave the least adsorption of 40% ± 9.9 for Cr(VI) and 80% ± 6.1 for Ni(II). The equilibrium data for the adsorption of Cr(VI) and Ni(II) on coconut husk was tested using both the Freundlich and Langmuir adsorption isotherms. The Freundlich isotherm was found to be more suitable for Cr(VI) adsorption, while the Langmuir isotherm was observed to better for Ni adsorption on coconut husk. To evaluate the mechanism of adsorption, pseudo-first order and second order kinetic models were used. The adsorption mechanism was found fit the second order. The HCl modified adsorbent gave the best result for removal of Cr(VI) from synthetic industrial effluents

Physicochemical Analysis of a Soil near Microbiology Laboratory at The University of Ilorin, Main Campus

In this study the physico-chemical analysis of a soil near microbiology laboratory at the University of Ilorin, main campus was carried out. The objectives of the study were to determine the soil parameters such as pH, moisture content, organic matter content, water holding capacity, temperature and soil texture in consideration of the soil’s suitability for microbial growth and plant development. Six soil samples were collected with interval of two weeks between two samples. pH range value was 7.10 to 7.82, the range of water holding capacity was from 0.28 ml per gram to 0.53 ml per gram of soil. The organic matter content of the soil samples ranged from 3.42% to 4.70%. The moisture content was discovered to range from 2.10% to 5.23%. The texture was discovered to be loamy sand with average composition of 89% sand, 7% silt and 4% clay. Keywords: soil texture, Organic Matter Content, Water Holding Capacity, Moisture content, Sand, Silt, Cla

Effects of Tillage and Leguminous Species on Selected Soil Physical Properties and Maize

Optimal use of management systems including tillage and legumes cover crops is recommended to improve soil physical properties and sustain agricultural production.  Field study was carried out to evaluate the effects of tillage practices and cropping systems on soil physical properties in Ogbomoso, Southern Guinea savanna, Nigeria. The two tillage practices (as main plot) No-till (NT) and Tilled (T) were investigated under five cropping systems (CS) of sole maize (SM), sole Mucuna (SMu), sole Pueraria, maize+Mucuna and maize + Pueraria intercrop with three replications in 2013. In 2014, all the treatments were similar except Canavalia gladiata that replaced Pueraria phaseolus. Soil physical parameters determined were; bulk density, pore size distribution, saturated hydraulic conductivity (Ksat), soil available water (SAW), soil temperature. Also, maize plant height and grain yield were determined. Data collected were analyzed by analysis of variance. The result shows that Ksat was significantly (P<0.05) 54% higher on NT > T. SAW was 11% significantly increased on NT>T in 2014. A 1.5% increase was observed in SMu plots compared with SM plots in 2013, though the treatments were similar. Soil temperature was significantly affected by tillage and CS at 6 WAS in 2013, 6 and 8 WAS in 2014.The trend is NT >T while SM > other cropping systems. There was significant interaction of tillage and cropping systems on Ksat in 2014. Maize grain yield was 39% significantly higher on T > NT in 2013. It is apparent that long term tillage and cropping systems experiment would be required to detect changes in soil physical properties as a result of the soil management practices. Keywords: Degradation, No-till, Tillage, Soil Physical Properties, Maize

Assessment of Landfill-emitted Gaseous Pollutants and Particulate Matters in Alimosho Local Government of Lagos state, Nigeria

Information on landfill-emitted pollutants in Nigeria cities has consequently become a priority. This study was designed to assess the air quality of landfill sites and the nearby communities in the Alimosho Local Government Area of Lagos state, Nigeria. Five public landfills in use since about thirty years ago were chosen for this study. A lightly populated area, free from other sources of air pollution served as control. Target points for the study were the centre of landfill (CLF), 50M from CLF, 100M from CLF, and a radius of 100M away from landfill. Levels of selected gaseous pollutants (NO2, O3, H2S and CO) and particulate matters (PM2.5 and PM10) were determined in the landfill environments and control (unpolluted area), using Aeroqual Series 500 with sensors for NO2, O3, H2S, CO, PM2.5 and PM10. The result showed that levels of H2S were significantly (p<0.001) higher at the CLF, 50M from CLF and 100M from CLF compared with unpolluted area. There was no significant (p>0.05) difference when the level of H2S in 100M radius was compared with the unpolluted area. Levels of CO were significantly (p<0.001) higher at the CLF, 50M from CLF, 100M from CLF and 100M radius compared with unpolluted area. The levels of O3 were significantly (p<0.001) higher at the CLF, 50M from CLF, 100M from CLF and 100M radius compared with unpolluted area. Levels of VOC were significantly (p<0.001) higher at the CLF, 50M from CLF, 100M from CLF and 100M radius compared with unpolluted area. The levels of NO2 were significantly (p<0.001) higher at the CLF, 50M from CLF, 100M from CLF and 100M radius compared with the unpolluted area. The levels of PM2.5 increased significantly (p<0.001) at the CLF, 50M from CLF, 100M from CLF and 100M radius compared with the unpolluted area. The levels of PM10 were also significantly (p< 0.001) higher at the CLF, 50M from CLF, 100M from CLF and 100M radius compared with the unpolluted area. In conclusion, communities close to landfills may be polluted with toxic gases and particulate matters. Further investigation is needed to validate the safe distance of residential areas from landfills to avert the risks of toxicity associated with gaseous pollutants

AN INVESTIGATION OF THE EFFECTS OF POOR SPECIFICATION ON BUILDING COLLAPSE IN NIGERIA

This paper examines the effects of specification on building collapse in Nigeria. The study became necessary due to the ugly cases of buildings collapsing in the country over the years. In doing so, the study begins with review of relevant literature on the concept of specification, as well as the factors associated with building collapse. The need for specification in building construction projects was enunciated upon. Other factors that culminate in building collapse, such as load types; man-power; technical skills, etc. are discussed herein. The study further examines identifies and documents cases of building collapse in Nigeria to identify the causes and factors responsible for the collapse. Interviews were conducted with practicing professionals in the construction industry. This was done to obtain professional insights and experiences used as part of the data in the research. Findings from this study highlights consequential role of poor specification in causing building collapse, loss of lives and properties. This paper concludes with identifying the relevance of specification in ensuring adherence to appropriate materials and construction methods for structural stability. Recommendations are given to guard against poor specifications that result in the collapse of buildings, properties and ultimately loss of lives

Multivariate analysis of potentially toxic metals in sediments of a tropical coastal lagoon

Surface sediments collected from the Lagos Lagoon, Nigeria, and three adjoining rivers were analysed for their physicochemical properties and pseudo-total concentration of the potentially toxic metals (PTM) Cd, Cr, Cu, Pb and Zn. The concentration of the PTM varied seasonally and spatially. Odo-Iyaalaro was observed to be the most polluted river, with highest concentrations of 42.1 mg kg(-1), 102 mg kg(-1), 185 mg kg(-1), 154 mg kg(-1) and 1040 mg kg(-1) of Cd, Cr, Cu, Pb and Zn, respectively, while Ibeshe River was the least contaminated, apart from a site affected by Cu from the textile industry. Some of the sediments were found to be above the consensus-based probable effect concentrations and Dutch sediment guideline for metals. Overall metal concentrations were similar to those reported for other tropical lagoon and estuarine systems affected by anthropogenic inputs as a result of rapid urbanisation. Due to the large number of samples, principal component analysis was used to examine relationships within the data set. Generally, sediments collected during the dry season were observed to have higher concentration of PTM than those collected during the rainy season. This means that PTM could accumulate over a prolonged period and then be released relatively rapidly, on an annual basis, into tropical lagoon systems

AN INVESTIGATION OF THE EFFECTS OF POOR SPECIFICATION ON BUILDING COLLAPSE IN NIGERIA

This paper examines the effects of specification on building collapse in Nigeria. The study became necessary due to the ugly cases of buildings collapsing in the country over the years. In doing so, the study begins with review of relevant literature on the concept of specification, as well as the factors associated with building collapse. The need for specification in building construction projects was enunciated upon. Other factors that culminate in building collapse, such as load types; man-power; technical skills, etc. are discussed herein. The study further examines identifies and documents cases of building collapse in Nigeria to identify the causes and factors responsible for the collapse. Interviews were conducted with practicing professionals in the construction industry. This was done to obtain professional insights and experiences used as part of the data in the research. Findings from this study highlights consequential role of poor specification in causing building collapse, loss of lives and properties. This paper concludes with identifying the relevance of specification in ensuring adherence to appropriate materials and construction methods for structural stability. Recommendations are given to guard against poor specifications that result in the collapse of buildings, properties and ultimately loss of lives

Use of Agricultural Wastes for the Immobilization of Metals in Polluted Soils in Lagos State, Nigeria

Background. An increase in human and industrial activities has led to an increase in the pollution of soils by metals. If these metals become bioavailable, there is potential for human exposure, leading to possible health effects. Remediation of soils is important to ensure that soil is suitable for agricultural purposes. Objectives. To explore the use of sawdust and cow dung to remediate contaminated soil by reducing the bioavailability of metals. Methods. Soil samples were collected from Oke Afa dumpsite and Owode Onirin metallic store and total metal concentrations were determined by digesting with aqua regia and analyzed using flame atomic absorption spectrophotometry. The effect of varied dosages (1–5%) of cow dung and sawdust on the immobilization of the selected metals was investigated, and results were compared with disodium hydrogen phosphate (DSHP) amendments. A single reagent leaching test was carried out with 0.1 M calcium chloride to determine the bioavailability of metals before and after amendment. Results. Before amendment, the amount of bioavailable metal in the soil sample from Oke Afa dumpsite was 57.5 mg/kg, 194 mg/kg and 17.5 mg/kg for copper (Cu), lead (Pb) and zinc (Zn), respectively, while in the second soil sample, from Owode Onirin metallic store, the amount of bioavailable Cu, Pb and Zn was observed to be 19.9 mg/kg, 36.4 mg/kg and 11.1 mg/kg, respectively. Up to 73.4% of mobile Zn was immobilized using DSHP, while cow dung and saw dust were effective in the immobilization of Cu and Pb, but not Zn. Conclusions. Cow dung and sawdust reduced the bioavailability of copper and lead, while Zn can be effectively immobilized with the use of DSHP. It was generally observed that the bioavailability of heavy metals decreased with increasing dosage of the amendments. Competing Interests. The authors declare no competing financial interests

Cellulase Production Potentials of the Microbial Profile of Some Sugarcane Bagasse Dumping Sites in Ilorin, Nigeria

This research work investigated cellulase production potentials of the microbial profile of three sugarcane bagasse dumping sites at Zango area, Ilorin, Nigeria. The microbial isolates were screened for cellulase production with a view to select the best organism for eventual cellulase production. Pour Plate method was used for the isolation and a total of thirteen (13) different organisms including both fungal and bacterial species were isolated and screened. Six (6) fungal isolates identified as Mucor racemosus, Aspergillus niger, Aspergillus flavus, Neurospora sitophilus, Penicillium oxalicum and Penicillium citrinum were isolated, while seven (7) different bacterial species isolated include Clostridium cellobioparum, Clostridium thermocellum,Bacillus subtilis, Bacillus pumillus, Lactobacillus spp, Pseudomonas flavescens and Serratia spp. Generally, bacterial isolates were more in abundance than fungal species. However; fungal isolates were constant and were isolated through the experimental period of three weeks. All the isolates showed cellulase production potential in varying degrees as reflected in the clearance zone around their colonies. Fungal isolates produced more cellulase than the bacterial isolates. Mucor racemosus had the highest clearance zone (75.0 mm) among the fungal isolates while Clostridium cellobioparum (35.0 mm) were the best producer among bacterial isolates. The least producer among fungal isolates, Penicillium citrinum (40.0 mm), is a little more than the bacterial cellulase producer (35.0 mm) and is far greater than the least bacterium Serratia spp (14.0 mm)