Environment
O. F. Anjorin; L. C. Imoh; C. Uhunmwangho
Abstract
Since actual metal emissions can be assessed using Particulate matter (PM) as a proxy, monitoring and controlling metal compounds in biomass emissions is essential for determining their quantities and potential health effects. Using a low volume respirable dust sampler, indoor ambient metal-bearing particles ...
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Since actual metal emissions can be assessed using Particulate matter (PM) as a proxy, monitoring and controlling metal compounds in biomass emissions is essential for determining their quantities and potential health effects. Using a low volume respirable dust sampler, indoor ambient metal-bearing particles were quantified in-situ and collected from nine (9) randomly selected public kitchens of boarding secondary schools in Jos, Plateau State. Atomic absorption spectrometry (AAS) was used to determine the amounts of specific heavy metals in these collected samples. Additionally, 114 responders' blood samples underwent a biochemical lead assay study. The mean concentrations of the samples taken for Mn, Cd, Cu, Fe, Cr, Zn, Ni, Pb, and Co were 0.097, 0.015, 0.254, 0.314, 1.027, 0.000, 0.076, 0.106, and 0.169 µg/m3, respectively. The results of the blood lead assay analysis showed that 54% of the subjects had B-Pb levels above 80 µg/dL, 33% had B-Pb levels between 40 µg/dL and 80 µg/dL, 8% between 25 µg/dL and 40 µg/dL, 4% between 10 µg/dL and 25 µg/dL, 4% below 10 µg/dL, and 15% below 10 µg/dL. In general, elevated levels of metal-bearing particles in the indoor environment public kitchens expose kitchen staff to several occupational hazards.
Environment
T. Yahaya; O. Ologe; C. Yaro; L. Abdullahi; H. Abubakar; A. Gazal; J. Abubakar
Abstract
The increasing prevalence of water-borne diseases necessitates periodic monitoring of domestic and drinking water sources. The current study assessed the safety of well water in the four emirate zones (Gwandu, Yauri, Argungu, and Zuru) of Kebbi State, Nigeria. Using normal procedures, samples of well ...
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The increasing prevalence of water-borne diseases necessitates periodic monitoring of domestic and drinking water sources. The current study assessed the safety of well water in the four emirate zones (Gwandu, Yauri, Argungu, and Zuru) of Kebbi State, Nigeria. Using normal procedures, samples of well water were examined for heavy metals, physicochemical characteristics, and microorganisms, and the results were compared to the World Health Organization (WHO) drinking water criteria. The heavy metals’ chronic daily ingestion (CDI) and hazard quotient (HQ) were also determined. The results showed that well water in the four emirate zones had normal temperature, biochemical oxygen demand (BOD), dissolved oxygen (DO), total suspended solids (TSS), and zinc (Zn). However, non-permissible concentrations of lead (Pb), iron (Fe), cadmium (Cd), chromium (Cr), and pH (Gwandu and Argungu only) were detected in all the water samples. Except for Cd and Cr in children, the CDI and HQ of the heavy metals were normal. The microbiological examinations revealed that the water samples from the four zones had abnormal levels of Bacillus species (bacteria), Escherichia coli (bacteria), Staphylococcus aureus (bacteria), Aspergillus niger (fungi), Mucor racemosa (fungi), and Paecilomyces variotti (fungi). The results obtained suggest that well water in the four zones is not suitable for human consumption unless treated.
Environment
R. A. Olaoye; S. O. Ojoawo; O. Bamigbade; N. Alimi; I. O. Rasaq; T. Oladejo
Abstract
The adhesion of metal ions from wastewater to surface of a material in an adsorption process had proven to be effective for remediation of wastewater before discharge. There is a growing demand to utilize alternative low-cost adsorbents for the removal of heavy metals from galvanic wastewater in most ...
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The adhesion of metal ions from wastewater to surface of a material in an adsorption process had proven to be effective for remediation of wastewater before discharge. There is a growing demand to utilize alternative low-cost adsorbents for the removal of heavy metals from galvanic wastewater in most developing countries. Cow bones are cheap, readily available and can be sourced locally from slaughterhouses and abattoir. Therefore, their use as an alternative adsorbent for remediation of galvanic wastewater had to be assessed. In this study, the efficacy of cow bone char (CBC) was assessed for simultaneous heavy metal ions removal from real life galvanic wastewater in a competitive adsorption process. The galvanic wastewater was characterized using atomic adsorption spectrophotometry while the CBC was characterized using X-ray Fluorescence (XRF), Scanning Electron Microscopy (SEM) and Fourier Transform Infrared (FTIR). Batch experiment was performed to determine the effect of adsorbent dose, contact time and agitation speed on the removal efficiency of heavy metal ions from the galvanized wastewater. The concentrations of Mn2+, Fe2+, Zn2+, Pb2+ and Cr2+ in the raw wastewater exceeded the WHO and EPA standards. The adsorbent revealed a significant distribution of well-developed porous, rough surfaces with cracks characterized by different functional groups for the efficient adsorption process. The optimum adsorbent dose for all the metal ions was 0.04 g/100 mL at an optimum contact time of 60 minutes except for Fe2+ with optimum contact time of 20 minutes, and agitation speed of 150 rpm. The maximum metal removal efficiencies obtained for Mn2+, Fe2+, Zn2+, Pb2+ and Cr2were 99.7%, 100%, 99%, 90% and 85% +, respectively. The average adsorption capacity for Mn2+, Fe2+, Zn2+, Pb2+ and Cr2+were 0.44 mg/g, 26.7 mg/g, 78.5 mg/g, 0.133 mg/g for and 10.36 mg/g, respectively. CBC offers efficient and cost-effective removal of selected metal ions from galvanized wastewater.
M. Karimizadeh; K. Payandeh
Abstract
This study was conducted in 2017 with the aim of determining the distribution of heavy metals lead, nickel, cadmium, vanadium and the parameters of acidity, electrical conductivity and organic matter in the surface soils of the city of Khorramabad. Sampling was performed monthly from 12 stations and ...
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This study was conducted in 2017 with the aim of determining the distribution of heavy metals lead, nickel, cadmium, vanadium and the parameters of acidity, electrical conductivity and organic matter in the surface soils of the city of Khorramabad. Sampling was performed monthly from 12 stations and was repeated 3 times in the autumn. The highest amount of cadmium was observed in the soil samples of industrial areas of the city in the two sampling periods of October and December to be 7 ppm. A comparison of the mean measured values of heavy elements showed that the highest average amounts of heavy elements are in industrial areas and the lowest in residential areas. The lowest amount was measured in 8th and 11th stations at 2 ppm. The highest amount of lead in the 6th station, a bustling area, was measured to be 22 ppm. The average nickel in industrial areas was higher than other areas. In industrial area, during the sampling period of October, its amount was determined to be 58 mg/kg. The highest amount of vanadium was recorded in staion9 at 52 mg/kg. Lead has a significant correlation with nickel, cadmium and soil acidity. This correlation is 0.01% for acidity and cadmium variables and 0.03% for nickel. Nickel has a significant correlation with cadmium and vanadium at the level of 0.01%. The results indicate that the surface soil of the city of Khorramabad is not contaminated with the studied metals. In general, the results showed that both human and natural factors are always involved in the distribution and concentration of heavy metals.
N. I. Ihimekpen; E. Atikpo; N. Kayode-Ojo; A. Michael
Abstract
The abilities of three indigenous bacteria for bioremediation of cadmium contaminated soils collected from Agbabu Farm Settlement close to mining sites in Ondo state, Nigeria was studied to provide helpful information for soils remediation and soils health management in this sub-region for Millennium ...
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The abilities of three indigenous bacteria for bioremediation of cadmium contaminated soils collected from Agbabu Farm Settlement close to mining sites in Ondo state, Nigeria was studied to provide helpful information for soils remediation and soils health management in this sub-region for Millennium Development Goals accomplishment. Bacillus subtilis, Proteus mirabilis, and Escherichia coli isolated from the soils were inoculated into different soil samples conditioned with optimized factors determined from the first phase experiments. The conditioned samples were experimented for residual cadmium concentration with time in days using Atomic Absorption Spectrophotometer. The soil cadmium attenuation from the initial concentration of 70.21 mg/kg to below the maximum allowable of 3 mg/kg was hard for the organisms. Bacillus subtilis performed correction at time 35 days with an efficiency of 96.10 % and residual concentration of 2.74 mg/kg. Proteus mirabilis and Escherichia coli with respective, high efficiencies of 85.05% and 79.35% failed. The removal rate capacities were -0.131d-1 for B. subtilis; -0.111d-1 for P. mirabilis; -0.105d-1 for E. coli. Four kinetic models fitted described the experimental data well. The models assessment revealed the removals to be transport controlled as diffusion process was the rate-controlling step.
A. Sumaila; M. M. Ndamitso; A. S. Ambali; Y. A. Iyaka; J. O. Tijani
Abstract
This work presents the green preparation of chitosan stabilized silver nanocomposite using aqueous leaf extracts of Nicotiana tobaccum. The prepared chitosan – silver nanocomposite was characterized by the ultraviolet-visible (UV-Vis) spectroscopy, X-ray diffraction (XRD), high resolution scanning ...
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This work presents the green preparation of chitosan stabilized silver nanocomposite using aqueous leaf extracts of Nicotiana tobaccum. The prepared chitosan – silver nanocomposite was characterized by the ultraviolet-visible (UV-Vis) spectroscopy, X-ray diffraction (XRD), high resolution scanning electron microscopy (HRSEM) and Fourier transform infrared (FTIR) spectroscopy. The nanocomposite was employed to remove copper and iron metal ions from electroplating effluent via batch adsorptions as a function of contact time, adsorbent dosage and temperature. The XRD results of the nanocomposite showed reflections at 2θ of 38.04°, 44.650 and 64.45° for the presence of silver nanoparticles and 9.29° and 19.300 for chitosan. The HRSEM image of the nanocomposite shows the silver nanoparticles embedded in the chitosan polymer matrix, to create pores on the surface of the chitosan. The maximum percentage removal of copper and iron by chitosan – silver nanocomposite were 94.76 % and 98.80 % respectively at temperature of 363 K in 60 minutes using adsorbent dosage of 25 mg. The results were well fitted by all the tested isotherm models but best fit into jovanovic isotherm models. Kinetic data for Cu and Fe ions followed the Elovich model which implies multilayer adsorption. The result of this study show that chitosan - silver nanocomposite has been prepared and it exhibit high adsorption efficiency for copper and iron from electroplating effluent.
S. S. Pandey; N. B. Singh; S. P. Shukla; M. Tiwari
Abstract
The aim of present study was to investigate the removal of lead and copper from textile wastewater using waste egg shells in a continuous stirred tank reactor. The effect of initial pH, metal concentration, adsorbent dosage and retention time were investigated. Optimum adsorption of lead (80%) was obtained ...
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The aim of present study was to investigate the removal of lead and copper from textile wastewater using waste egg shells in a continuous stirred tank reactor. The effect of initial pH, metal concentration, adsorbent dosage and retention time were investigated. Optimum adsorption of lead (80%) was obtained at pH 6, initial metal concentration 20 mg/L, adsorbent dosage 12.5 g/L and retention time 90 minute. Also, optimum adsorption of copper (71%) was obtained at pH 6, initial metal concentration 15 mg/L, adsorbent dosage 15 g/L and retention time 75 minute. Langmuirs, Freundlich and Temkin isotherms were used for the mathematical description of adsorption equilibrium. Langmuir isotherm showed the best fitting to the isotherm equilibrium data, with a maximum adsorption capacity (qm) of 4.33 mg/g and 3.54 mg/g for lead and copper, respectively. Results revealed that pseudo-second order adsorption kinetic equation fit the data with a high correlation coefficient (R2 more than 0.97). Based on the results of the present study, egg shells is suitable to be used for the removal of lead and copper from textile wastewater.
K. Fahmida; I. M. Rafizul
Abstract
The principle objective of this study was to evaluate the soil quality and the level of contamination of soil by heavy metals adapting various developed index in a selected waste disposal site at Rajbandh, Khulna, Bangladesh. To theses ...
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The principle objective of this study was to evaluate the soil quality and the level of contamination of soil by heavy metals adapting various developed index in a selected waste disposal site at Rajbandh, Khulna, Bangladesh. To theses endeavor, ten soil samples were collected from the selected locations and then the relevant elements of Al, Fe, Mn, Cr, Cu, Pb, Zn, Ni, Cd, As, Co, Sb, Sc and Hg were measured and monitored using standard method. To estimate the contamination situation of soil, contamination factor (CF), enrichment factor (EF) and geo-accumulation index (Igeo) and potential ecological risk index (PERI) were computed using geological background values. In addition, for assessing soil quality, Pearson's correlation coefficients analysis was also performed. Furthermore, this study revealed that the values of CF and Igeo in soils around the waste disposal area affected from the contamination of heavy metals mostly by Pb, Cd and Sb. In contrast, Pearson's correlation indicated that the sources of metals are almost the same and these heavy metals might be derived from the waste accumulation activity. Dump sites have great potential for energy extraction if the high valued compounds to be extracted.
S. O. Ayoola; G. T. Olorunsanmi; A. O. Oke
Abstract
Industrial waste discharge has increased the hazard of water pollution. The total hydrocarbon content and bioaccumulation of heavy metals in Sarotherodon melanotheron at Atlas cove area and at Okobaba end of Lagoon Lagos were assessed between November, 2014 and January, 2015. The physicochemical parameters ...
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Industrial waste discharge has increased the hazard of water pollution. The total hydrocarbon content and bioaccumulation of heavy metals in Sarotherodon melanotheron at Atlas cove area and at Okobaba end of Lagoon Lagos were assessed between November, 2014 and January, 2015. The physicochemical parameters were determined according to APHA-AWWA-WEF and heavy metals in the fish species were determined using Atomic Absorption Spectrometer. The total hydrocarbon content (THC) in the fish samples were analysed by using Soxhlet extraction gravimetric methods. The heavy metal values evaluated are Fe, Cr, Pb, Ni and Cu. The concentration of Iron (Fe) in Sarotherodon melanotheron was 72.72 ± 125.95mg/kg, Chromium (Cr)- 10.29 ± 4.61mg/kg; Lead (Pb)- 1.08 ± 0.23mg/kg; Nickel (Ni)- 0.39 ± 0.26mg/kg; and Copper (Cu)- 0.20 ± 0.26mg/kg at Atlas cove area while at Okobaba the concentration were;Fe-115.98±87,Cr-5.25±1.02,Pb-2.04±1.50,Ni-0.78±0.08,and Cu is 0.36±0.15mg/kg. The levels of accumulation of all the heavy metals in Sarotherodon melanotheron were above the WHO permissible limits. The concentration of n- alkanes in Sarotherodon melanotheron at Atlas cove was 164.69 ± 97.04µg/g, polycyclic aromatic hydrocarbon (PAH) was 73.58 ± 72.48µg/g, and total petroleum hydrocarbon was 526.67 ± 214.34µg/g. The average intake of polycyclic aromatic hydrocarbon through fish consumption at Atlas cove area was estimated to be 5039.94 ± 49.2mg/kg; body weight/day. The mean concentration of n-alkanes hydrocarbon in Sarotherodon melanotheron at Okobaba was 152.62±54.11µg/g, the PolycyclicAromatic Hydrocarbon (PAH) was 74.4±50.30 µg/g.The carcinogenic high molecular weight polycyclic aromatic hydrocarbons (HMW-PAH) were of higher concentrations than the lower molecular weight polycyclic aromatic hydrocarbon (LMW-PAH). Therefore, Atlas cove area is more exposed to carcinogenic health risks associated with the consumption of the studied fish than Okobaba end of Lagos Lagoon. This indicates significant carcinogenic health risks associated with the consumption of black jaw Tilapia fish caught from the study areas.
A. Harlina; M. Maheera; I. Norli
Abstract
This batch study focuses on suitability of laterite soil-pressmud as daily soil cover of landfill. The laterite soil samples were mixed with waste from sugar refinery process, namely pressmud at different percentages of weight ratio (10, 30 and 50%). The batch equilibrium tests were carried out ...
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This batch study focuses on suitability of laterite soil-pressmud as daily soil cover of landfill. The laterite soil samples were mixed with waste from sugar refinery process, namely pressmud at different percentages of weight ratio (10, 30 and 50%). The batch equilibrium tests were carried out and glaringly showed that the laterite soil-pressmud mixtures have the capability to remove more than 62% of Cr, Cu, Mn, Ni, Pb and Zn concentration in leachate. Meanwhile, the removal efficiency of heavy metals from leachate in the laterite soil alone was lower than 50%. Pressmud alone however showed more than 53% removal. The laterite soil-pressmud mixtures, particularly at 30 and 50 percent of pressmud signify great potential as daily soil cover in reduction of heavy metals migration in landfill leachate.
S. Sasikala; Govindaraju Muthuraman
Abstract
The potential of economically cheaper Tribulus terrestris was assessed for iron adsorption from aqueous solutions. The effects of pH, Contact time, sorbent dose, initial metal ion concentration and temperature on the uptake of iron were studied in batch process. Chemical treatment processes are ineffective ...
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The potential of economically cheaper Tribulus terrestris was assessed for iron adsorption from aqueous solutions. The effects of pH, Contact time, sorbent dose, initial metal ion concentration and temperature on the uptake of iron were studied in batch process. Chemical treatment processes are ineffective and produce large quantity of sludge which requires further treatment. A simple and efficient treatment process for the removal of heavy metals is essentially required. Maximum iron removal was observed at pH 6 with adsorbent dosage of 0.6 g. The adsorbent data has been correlated with Langmuir and Freundlich adsorption models. FTIR and SEM before and after adsorption were recorded to explore the number and position of the functional groups available for iron binding onto the studied adsorbent and changes in surface morphology. The maximum percentage of iron removal was achieved at 87%. The results revealed that iron is considerably adsorbed on Tribulus terrestris and it could be economical method for the removal of iron from aqueous solutions. Pseudo second order model explains the iron kinetics more effectively.
