Temporal variability of heavy metal content in the atmosphere of Ketu- mile 12 area of Lagos - State, southwestern - Nigeria using moss plant Polytrichum juniperum as bioindicator

The concentrations of the five heavy metals; Zinc (Zn), Lead (Pb), Cadmium (Cd), Nickel (Ni) and Copper (Cu) were determined using Atomic Absorption Spectrophotometer (AAS). Results of the analysis, shows that the average concentration of the heavy metals at Ketu - Mile 12 were : Zn 7.175mg/L; Pb 1.288mg/l; Cu 0.531mg/l; Ni 0.223mg/l and Cd 0.021mg/l which reflects Zn 77.67; Pb 13.94; Cu 5.75; Ni 2.41 and Cd 0.22 % with the most abundant pollutant heavy metal being Zn in all the sites while the least abundant was Cd. It was found that the highest concentration of each heavy metals in all the sites were as follow; Zn 14.93mg/l - Alapere; Pb 1.720mg/l - Ketu garage; Cd 0.118mg/l - Mile 12 market; Ni 0.458mg/l - Mile 12 and Cu 0.956mg/I - Ketu garage while the least concentration of heavy metals in all the sites were as follows: Zn < 0.005mg/l, Pb < 0.001mg/l), Cd < 0.001mg/l and Cu 0.106mg/l - Oniru, Ni 0.108mg/ - Iyana school. The most polluted site was Ikosi road 4.441 mg/l while the least polluted was Iyana School 0.327mg/l. The sequence of bioaccumulation and distribution follows the pattern thus: Zn>Pb>Cu>Ni >Cd.Keywords: Bioaccumulation, Pollution, Spectrophotometer, Bioindicator, Anthropogenic, Concentration

Fire extinguishing strength of the combustion product of wood saw dust (ash)

Forty saw dust samples from four mature hard wood plants grown in southwestern part of Nigeria were analyzed for their ash contents, moisture contents, metallic contents and hence the fire extinguishing strength of the saw dust ash by classical and instrumental methods of analyses. Mahogany (Khaya ivorensis) wood saw dust ash had the highest mean metallic content (5.989±2.51ppm) followed by Opepe (Sarcocephalus latifolius) , 4.704±0.21ppm while Poro poro (Sorghum bicolour) wood ash had the least metallic content (1.611±0.48ppm). Mahogany also had the highest mean moisture content (2.6615±0.64) while Opepe had the least moisture content (0.9362±0.45). The fire extinguishing strength of Mahogany was the highest, and had a positive correlation with its metallic content as depicted by their correlation coefficient (0.850). Poro poro had the least fire extinguishing strength. The comparison of the extinguishing strength of wood saw dust samples and the commonly used ABC fire extinguisher showed that ABC fire extinguisher has more extinguishing strength than the wood saw dust ash. Hence, improvement on the extinguishing strength of the saw dust ash is necessary. © JASE

Evaluation of levels of atmospheric heavy metals in Ikeja Industrial Area of Lagos state Nigeria using Polytrichum commune as biomonitor

This study investigates the concentrations of some heavy metals (Zn, Pb, Cu, Ni and Cd) in moss plant Polytrichum commune collected at different locations within Ikeja Industrial Area, Lagos - Nigeria. The samples of the plant were collected randomly between September and November, 2018 at 10 different locations between 2 - 2.5 m high from unplastered buildings. The samples were properly cleaned from all the debris, weighed and digested with a mixture of HNO3 and H2O2 for 35 min. The concentrations of heavy metals were analyzed using Atomic Absorption Spectrophotometer (AAS). The results obtained, showed that the average concentrations of the heavy metals at Ikeja Industrial Area were: Zn 16.01944 mg/dm3, Pb 2.9485 mg/dm3, Cu 2.7843 mg/dm3, Ni 0.6653 mg/dm3 and Cd 0.095 mg/dm3 which reflects 71.16; 13.10; 12.37; 2.96 and 0.42% respectively with the most abundant pollutant heavy metal being Zn in all the sites while the least abundant was Cd. Similarly, the most polluted site was Manufacturing Production Limited (40.894mg/L; 18.1%), while the least polluted site was Kara.com.ng (9.891mg/L; 4.4%). The levels of heavy metals obtained are greater than the permissible limits prescribed by the Federal Ministry of Environment, European Communities and United Nations Environmental Programme. There was significant difference in the level of each heavy metal in the atmosphere of Ikeja Industrial Area (PV < 0.05).The sequence of bioaccumulation and distribution follows the trends: Zn > Pb > Cu > Ni > Cd

Fire extinguishing strength of the combustion product of wood saw dust (ash)

Forty saw dust samples from four mature hard wood plants grown in southwestern part of Nigeria were analyzed for their ash contents, moisture contents, metallic contents and hence the fire extinguishing strength of the saw dust ash by classical and instrumental methods of analyses. Mahogany ( Khaya ivorensis ) wood saw dust ash had the highest mean metallic content (5.989\ub12.51ppm) followed by Opepe ( Sarcocephalus latifolius ), 4.704\ub10.21ppm while Poro poro (Sorghum bicolour) wood ash had the least metallic content (1.611\ub10.48ppm). Mahogany also had the highest mean moisture content (2.6615\ub10.64) while Opepe had the least moisture content (0.9362\ub10.45). The fire extinguishing strength of Mahogany was the highest, and had a positive correlation with its metallic content as depicted by their correlation coefficient (0.850). Poro poro had the least fire extinguishing strength. The comparison of the extinguishing strength of wood saw dust samples and the commonly used ABC fire extinguisher showed that ABC fire extinguisher has more extinguishing strength than the wood saw dust ash. Hence, improvement on the extinguishing strength of the saw dust ash is necessary

Synthesis, spectroscopic characterization and anti-microbial activities of (z)-4-(4-(dimethylamino)benzylideneamino)-1, 5-dimethyl-2-phenyl-1h-pyrazol-3(2h)-one schiff base ligand and its divalent metal complexes

Five Schiff base complexes derived from Ni(II), Zn(II), Cu(II), Co(II) and Fe(II) salts were prepared and investigated using FTIR, 13CNMR, 1HNMR, GCMS, and UV/Visible electronic spectra. The Schiff base was derived from a reaction between 4-aminoantipyrine and 4-(N,N-dimethylamino)benzaldehyde. The ligand formed was complexed with different metals salts to study their chemical and microbial behaviours. From the results, the Infra-red data revealed the proper coordination sites of the ligand to the metal ions and displayed the different groups in the compounds. The UV/Visible electronic spectra data showed the different transfers and transitions in the ligand and metal complexes. The different absorptions in the electronic spectra also predicted the possible structures of the complexes. The 13CNMR and 1HNMR showed the different carbon and hydrogen environments in the ligand and complexes. The GCMS confirmed the structure of the ligand and exhibited different fragments. The antimicrobial activities of the ligand were enhanced with the metal complexes and the results were very interesting as the complexes showed good antifungal and antibacterial activities.Key Words: 4-aminoantipyrine, antibacterial, antifungal, complexes, Schiff bas

Data on anti-corrosion characteristics of eco-friendly inhibitive extract on the hot corrosion degradation trend of A6063 aluminum alloy in 1.0 M HCl solution

The study of Lasienthera africanum as corrosion inhibitor for A6063 grade aluminum alloy in 1.0 M HCl acid solution using weight loss method of corrosion study was investigated at 30 °C and 40 °C to check its degradation trend at high varying temperature application. The results revealed that L. africanum in 1.0 M acidic environment decreased the corrosion rate at various concentrations considered. Inhibitor efficiency (IE) as high as 98.7 and 94.9% both at 30 °C and 40 °C respectively, was observed. Keywords: Inhibitor efficiency, Temperature, HCl solution, Lasienthera africanu

Temporal variability of heavy metal content in the atmosphere of Mushin Area of Lagos - State, southwestern - Nigeria using Barbulaindica (Hook) spreng.var.indica as bioindicator

This research reports the results of some heavy metal content (Zn, Pb,Cd, Ni and Co) in Mushin area of Lagos - State using the moss plant Barbulaindica (Hook) spreng.var.indica as bioindicator. The samples of the Moss plant were collected randomly from September to November, 2016 at ten different locations at Mushin area between 2 to 2.5 metres high from unplastered buildings in Lagos state and analysed for their heavy metal contents as at the time of sampling. The samples were properly cleaned from all the debris then weighed and digested with a mixture of HN03 and H2O2 for 35 min. The concentrations of the five heavy metals were determined using Atomic Absorption Spectrophotometer (AAS). Results of the analysis, shows that the average concentration of the heavy metals at Mushin are: Zn 23.477mg/l,53.9%; Pb 4.240mg/l,9.74%; Cd 0.195mg/l,0.45%; Ni 4.418mg/l, 10.15% and Co 11.191mg/l,25.71%. The most abundant pollutant heavy metal was Zn in all the sites while the least abundant was Cd. Levels of some of the heavy metals were present in concentrations greater than WHO (2001) threshold limiting values. The most polluted site is Olorunshogo 11.809mg/l while the least polluted is Shoremekun 1.2765mg/l. The sequence of bioaccumulation and distribution follows the pattern: Zn > Co > Ni > Pb > Cd. The concentrations of heavy metals obtained exceeded the recommended limits of the Federal Ministry of Environment (FME), European communities (EC) and United Nations Environmental Programme (UNEP) permissible level for heavy metals in the atmosphere which suggests that the study area is polluted with heavy metals. There is a significant high level of each heavy metal in the atmosphere of Mushin areas (Pvalue< 0.05).Keywords: Anthropogenic, bioaccumulation, bioindicator, concentrations, pollution, spectrophotomete

Levels of heavy metals, total hydrocarbon and organic carbon contents of sediments from Ikpoba (Edo) and Ethiope (Delta) Rivers of Nigeria

The sediment samples of River Ethiope and Ikpoba River were collected and extracted using n-hexane (BDH, England) and the resulting extracts were read at 460nm with a spectrophotometer. The heavy metal analysis was carried out by using atomic absorption spectroscopy. The organic carbon was determined by titrimetric method. The results show that the organic carbon contents were 0.53mg/kg (Ikpoba river) and 0.40mg/kg (Ethiope river). THC contents were 6.50mg/kg (Ikpoba river) and 42.10mg/kg (Ethiope river). The organic contents were very low in both river sediments. The low Organic contents could be attributed to the constant flow of the rivers. Generally, higher hydrocarbon concentrations are often recorded in stations that have oil formations than those without oil formations. Some of the results obtained for the heavy metals analysis were higher than the WHO standards. The THC analysis from Ikpoba river sediment was lower compared to WHO standards, while the THC in Ethiope river sediment was higher than the WHO standard. Overall, the parameters analysed were detected in both river sediments, but in varied concentrations.Keywords: Heavy metals, Total hydrocarbon, Organic carbo

Silver Nanoparticles Mediated by Costus afer Leaf Extract: Synthesis, Antibacterial, Antioxidant and Electrochemical Properties

Synthesis of metallic and semiconductor nanoparticles through physical and chemical routes has been extensively reported. However, green synthesized metal nanoparticles are currently in the limelight due to the simplicity, cost-effectiveness and eco-friendliness of their synthesis. This study explored the use of aqueous leaf extract of Costus afer in the synthesis of silver nanoparticles (CA-AgNPs). The optical and structural properties of the resulting silver nanoparticles were studied using UV-visible spectroscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM) and Fourier transform infra–red spectrophotometer (FTIR). TEM images of the silver nanoparticles confirmed the existence of monodispersed spherical nanoparticles with a mean size of 20 nm. The FTIR spectra affirmed the presence of phytochemicals from the Costus afer leaf extract on the surface of the silver nanoparticles. The electrochemical characterization of a CA-AgNPs/multiwalled carbon nanotubes (MWCNT)-modified electrode was carried out to confirm the charge transfer properties of the nanocomposites. The comparative study showed that the CA-AgNPs/MWCNT-modified electrode demonstrated faster charge transport behaviour. The anodic current density of the electrodes in Fe(CN)6]4−/[Fe(CN)6]3− redox probe follows the order: GCE/CA-Ag/MWCNT (550 mA/cm2) > GCE/MWCNT (270 mA/cm2) > GCE (80 mA/cm2) > GCE/CA-Ag (7.93 mA/cm2). The silver nanoparticles were evaluated for their antibacterial properties against Gram negative (Escherichia coli, Klebsiella pneumonia, Pseudomonas aeruginosa) and Gram positive (Bacillus subtilis and Staphylococcus aureus) pathogens. The nanoparticles exhibited better inhibition of the bacterial strains compared to the precursors (leaf extract of Costus afer and silver nitrate). Furthermore, the ability of the nanoparticles to scavenge DPPH radicals at different concentrations was studied using the DPPH radical scavenging assay and compared to that of the leaf extract and ascorbic acid. The nanoparticles were better DPPH scavengers compared to the leaf extract and their antioxidant properties compared favorably the antioxidant results of ascorbic acid. The green approach to nanoparticles synthesis carried out in this research work is simple, non-polluting, inexpensive and non-hazardous

Green Synthesis of Ag/Ag2O Nanoparticles Using Aqueous Leaf Extract of Eupatorium odoratum and Its Antimicrobial and Mosquito Larvicidal Activities

The health challenges associated with pathogens and ectoparasites highlight the need for effective control approaches. Metal nanoparticles have been proposed as highly effective tools towards combatting different microbial organisms and parasites. The present work reports the antimicrobial and larvicidal potential of biosynthesized Ag/Ag2O nanoparticles using aqueous leaf extract of Eupatorium odoratum (EO). The constituents of the leaf extract act as both reducing and stabilizing agents. The UV-VIS spectra of the nanoparticles showed surface plasmon resonance. The particle size and shape of the nanoparticles was analysed by transmission electron microscopy (TEM). The larvicidal study was carried out using third and fourth instar Culex quinquefasciatus larvae. The mosquito larvae were exposed to varying concentrations of plant extract (EO) and the synthesized nanoparticles, and their percentage of mortality was accounted for at different time intervals of 12 h and 24 h periods of exposure. The nanoparticles were more lethal against third and fourth instars of Culex quinquefasciatus larvae at the 24 h period of exposure with lower lethal concentration values (LC50 = 95.9 ppm; LC90 = 337.5 ppm) and (LC50 = 166.4 ppm; LC90 = 438.7 ppm) compared to the plant extract (LC50 = 396.8 ppm; LC90 = 716.8 ppm and LC50 = 448.3 ppm; LC90 = 803.9 ppm, respectively). The antimicrobial properties of the nanoparticles were established against different clinically-isolated microbial strains and compared to that of the plant extract (EO) and standard antimicrobial drugs. The nanoparticles were generally more active than the plant extract against the selected microbial organisms. The Gram-negative bacterial strains Escheerichua coli and Salmonella typhi were more susceptible towards the nanoparticles compared to the Gram-positive strains and the fungal organism