Results of regression analyses and the individual variances explained by the investigated conditi... more Results of regression analyses and the individual variances explained by the investigated conditions. (DOCX 15Â kb)
Cassava, a staple crop in Nigeria, processed by numerous factories in rural and sub-urban locatio... more Cassava, a staple crop in Nigeria, processed by numerous factories in rural and sub-urban locations is known to contain some level of cyano compounds. Lack of stringent environmental regulations on management of cassava wastewater (CWW) from cassava processing factories had led to its indiscriminate discharge on the environment. CWW samples were obtained from cassava processing factories from selected states (Lagos (A), Oyo (B), Ogun 1 (C1), Ogun 2 (C2) and Cross River (D)) in Nigeria to determine the cytotoxic and genotoxic effects of extracted cyanide from the wastewaters. The cyanide was hydrolyzed via chemical degradation utilizing 1.25 M NaOH and subsequently titrated using silver nitrate with p-dimethylaminobenzalrhodamine as indicator. Further, in order to explore the potential toxicity of this pollutant present in the effluent, a battery of short-term biological assay (Allium cepa chromosomal aberration test) was used. Bulbs with roots of Allium cepa L. were treated with different concentrations (0.05%, 0.1%, 0.2%, 0.4%, and 0.8%) of CWW, and after 48 h the root tips were processed for cytological studies by the aceto-orcein squash procedure. The results revealed that cyanide concentrations on re-fluxing were in the range of 1.0 mg/L and 1.3 mg/L. All concentrations induced a number of chromosomal aberrations in the root tip cells. The mitotic index decreased significantly (p < 0.05) with increasing concentration. The cytotoxic effects showed strong concentration dependent root growth inhibition with EC50 values of 30, 20, 37, 43 and 22 % for A, B, C1, C2 and D, after 72 h. The findings thus indicate that alkali treatment is very efficient in degrading the cyanide content of CWW and has shown that the combination of physico-chemical analysis along with the sole toxicity assessment could provide valuable information about the sole toxicity of cyanide as a chemical pollutant present in the cassava effluent.
Results of regression analyses and the individual variances explained by the investigated conditi... more Results of regression analyses and the individual variances explained by the investigated conditions. (DOCX 15Â kb)
Understanding the components of pharmaceutical wastewaters and their potential risk as sources of... more Understanding the components of pharmaceutical wastewaters and their potential risk as sources of pollution when discharged into the environment is imminent for environmental and public health significance. This study was aimed at evaluating untreated wastewaters from pharmaceutical industries in Nigeria. Results obtained showed that the colors of the wastewaters were mostly turbid, few in brown and only one colorless sample; revealed high turbidity (16 - 999 NTU). The pH ranged from 2.9 to 9.2, whereas phosphate and nitrate levels were between the ranges of 0.0122-15.66 mg/L and 0.18-87.02 mg/L respectively. Heavy metal analysis showed high levels of iron at 53.53 mg/L and 25.6 mg/L, with chromium at 7.190 mg/L. The BOD and COD were high for most of the wastewaters. Bacteria isolates were detected in all samples with population ranging from 3.0 x 104 cfu/mL to 2.7 x 1012 cfu/mL, while fungi was averaged at 7.0 x 105 cfu/mL and total coliform was between 2.6 x 102 to 2.7 x 107 cfu/m...
Cassava, a staple crop in Nigeria, processed by numerous factories in rural and sub-urban locatio... more Cassava, a staple crop in Nigeria, processed by numerous factories in rural and sub-urban locations is known to contain some level of cyano compounds. Lack of stringent environmental regulations on management of cassava wastewater (CWW) from cassava processing factories had led to its indiscriminate discharge on the environment. CWW samples were obtained from cassava processing factories from selected states (Lagos (A), Oyo (B), Ogun 1 (C1), Ogun 2 (C2) and Cross River (D)) in Nigeria to determine the cytotoxic and genotoxic effects of extracted cyanide from the wastewaters. The cyanide was hydrolyzed via chemical degradation utilizing 1.25 M NaOH and subsequently titrated using silver nitrate with p-dimethylaminobenzalrhodamine as indicator. Further, in order to explore the potential toxicity of this pollutant present in the effluent, a battery of short-term biological assay (Allium cepa chromosomal aberration test) was used. Bulbs with roots of Allium cepa L. were treated with different concentrations (0.05%, 0.1%, 0.2%, 0.4%, and 0.8%) of CWW, and after 48 h the root tips were processed for cytological studies by the aceto-orcein squash procedure. The results revealed that cyanide concentrations on re-fluxing were in the range of 1.0 mg/L and 1.3 mg/L. All concentrations induced a number of chromosomal aberrations in the root tip cells. The mitotic index decreased significantly (p < 0.05) with increasing concentration. The cytotoxic effects showed strong concentration dependent root growth inhibition with EC50 values of 30, 20, 37, 43 and 22 % for A, B, C1, C2 and D, after 72 h. The findings thus indicate that alkali treatment is very efficient in degrading the cyanide content of CWW and has shown that the combination of physico-chemical analysis along with the sole toxicity assessment could provide valuable information about the sole toxicity of cyanide as a chemical pollutant present in the cassava effluent.
International Journal of Environmental Analytical Chemistry, 2020
The quantitation of nutrient species in the saline water of the Lagos Lagoon was carried out usin... more The quantitation of nutrient species in the saline water of the Lagos Lagoon was carried out using flow injection analysis (FIA). Due to the Schlieren effect (SE), occasioned by the formation of fr...
International Journal of Environmental Analytical Chemistry, 2020
The quantitation of nutrient species in the saline water of the Lagos Lagoon was carried out usin... more The quantitation of nutrient species in the saline water of the Lagos Lagoon was carried out using flow injection analysis (FIA). Due to the Schlieren effect (SE), occasioned by the formation of fr...
Roadside soils were sampled from the Lagos Lagoon catchment during the wet and dry seasons over t... more Roadside soils were sampled from the Lagos Lagoon catchment during the wet and dry seasons over the period 2005-2009. Lagoon sediment samples were also collected within the same period. All samples were digested with aqua regia to determine total phosphorus and extracted with 0.5 M sodium bicarbonate to determine the bioavailable fraction (Olsen-P). A segmented flow analyser method was used for analysis and good accuracy was demonstrated for two reference soils (SO-2 from CCMET and SRM 2711 from NIST). The Lagos Lagoon is a hypereutrophic water body (1270 ± 1170 μg P L(-1)), with significant areas of anoxia and water hyacinth growth. The total phosphorus concentrations in roadside soils (16 sites; mean ± 2 S.D.) were 285 ± 279 mg kg(-1) in the wet season and 424 ± 629 mg kg(-1) in the dry season, indicating that rainwater leaching is a major source of phosphorus in the lagoon. The bioavailable fractions were 5.17 ± 3.47 mg kg(-1) (2.1 ± 1.5% of the total) in the wet season and 13.0 ± 8.7 mg kg(-1) (4.3 ± 4.5% of the total) in the dry season.
Sub-Saharan Africa is seeing rapid urbanization, with the population of cities such as Lagos and ... more Sub-Saharan Africa is seeing rapid urbanization, with the population of cities such as Lagos and Nairobi growing at a rate of 3–4% a year. The region is extremely under-sampled for all air pollutants, particularly VOCs, which are useful markers for source apportionment as well as toxic in their own right. There are many contributors to air pollution in the region, and studies examining fine particulate pollution implicate traffic as the primary source in urban areas. In this pilot study, VOCs were analysed at a selection of roadside and urban background locations in Nairobi and Lagos, and 74 VOCs were quantified. GC×GC–MS/FID analysis revealed all locations were dominated by hydrocarbons typical of vehicle emissions, with the aromatic hydrocarbons benzene and toluene among the most abundant VOCs. Typical personal exposure scenarios for citizens of the cities were calculated to far exceed those of a resident in a city in Europe/US. Finally, the calculated ozone forming potential of t...
Surface water pollution has been found to be considerably driven by the contributions of airborne... more Surface water pollution has been found to be considerably driven by the contributions of airborne particles, open-air waste burning and fossil fuel combustion, ammonia volatilization from excreta, fertilizer and derivatives from explosive factories. Atmospheric deposition into the Lagos Lagoon is suspected to be a major contributor to the nutrient levels of the lagoon. Atmospheric dry nutrient deposition was monitored at six stations around the Lagos Lagoon from January to June 2012 in order to estimate the contribution of atmospheric deposits into the lagoon&#39;s nutrient cycles. Species of phosphorus (P) and nitrogen (N) in the lagoon water were analyzed by colorimetric methods. Mean [NO(-) 3 + NO(-) 2]-N was 3.08 ± 2.10 mg m(-2) day(-1) (0.55-8.73 mg m(-2) day(-1)). The (NO(-) 3 + NO(-) 2)-N was only about 2 % of total N but [NH(+) 4 + organic]-N was approximately 38 % of total N. Particulate N was about 60 % of total N. Average total N was 144 ± 94.9 mg m(-2) day(-1) (48.0-285 mg m(-2) day(-1)). Average soluble reactive P was significantly lower than [NO(-) 3 + NO(-) 2]-N averaging about 0.12 ± 0.12 mg m(-2) day(-1). Soluble reactive P (SRP) was less than 2 % of total P but soluble organic P was about 86 % of total P. Particulate P accounted for about 12 % of total P. Average total P was 4.56 ± 10.1 mg m(-2) day(-1) (0.48-31.6 mg m(-2) day(-1)). This study shows that atmospheric deposition of nutrients into the Lagos Lagoon is taking place and this may represent a considerable proportion of the total nutrient loading of the lagoon.
Results of regression analyses and the individual variances explained by the investigated conditi... more Results of regression analyses and the individual variances explained by the investigated conditions. (DOCX 15Â kb)
Cassava, a staple crop in Nigeria, processed by numerous factories in rural and sub-urban locatio... more Cassava, a staple crop in Nigeria, processed by numerous factories in rural and sub-urban locations is known to contain some level of cyano compounds. Lack of stringent environmental regulations on management of cassava wastewater (CWW) from cassava processing factories had led to its indiscriminate discharge on the environment. CWW samples were obtained from cassava processing factories from selected states (Lagos (A), Oyo (B), Ogun 1 (C1), Ogun 2 (C2) and Cross River (D)) in Nigeria to determine the cytotoxic and genotoxic effects of extracted cyanide from the wastewaters. The cyanide was hydrolyzed via chemical degradation utilizing 1.25 M NaOH and subsequently titrated using silver nitrate with p-dimethylaminobenzalrhodamine as indicator. Further, in order to explore the potential toxicity of this pollutant present in the effluent, a battery of short-term biological assay (Allium cepa chromosomal aberration test) was used. Bulbs with roots of Allium cepa L. were treated with different concentrations (0.05%, 0.1%, 0.2%, 0.4%, and 0.8%) of CWW, and after 48 h the root tips were processed for cytological studies by the aceto-orcein squash procedure. The results revealed that cyanide concentrations on re-fluxing were in the range of 1.0 mg/L and 1.3 mg/L. All concentrations induced a number of chromosomal aberrations in the root tip cells. The mitotic index decreased significantly (p < 0.05) with increasing concentration. The cytotoxic effects showed strong concentration dependent root growth inhibition with EC50 values of 30, 20, 37, 43 and 22 % for A, B, C1, C2 and D, after 72 h. The findings thus indicate that alkali treatment is very efficient in degrading the cyanide content of CWW and has shown that the combination of physico-chemical analysis along with the sole toxicity assessment could provide valuable information about the sole toxicity of cyanide as a chemical pollutant present in the cassava effluent.
Results of regression analyses and the individual variances explained by the investigated conditi... more Results of regression analyses and the individual variances explained by the investigated conditions. (DOCX 15Â kb)
Understanding the components of pharmaceutical wastewaters and their potential risk as sources of... more Understanding the components of pharmaceutical wastewaters and their potential risk as sources of pollution when discharged into the environment is imminent for environmental and public health significance. This study was aimed at evaluating untreated wastewaters from pharmaceutical industries in Nigeria. Results obtained showed that the colors of the wastewaters were mostly turbid, few in brown and only one colorless sample; revealed high turbidity (16 - 999 NTU). The pH ranged from 2.9 to 9.2, whereas phosphate and nitrate levels were between the ranges of 0.0122-15.66 mg/L and 0.18-87.02 mg/L respectively. Heavy metal analysis showed high levels of iron at 53.53 mg/L and 25.6 mg/L, with chromium at 7.190 mg/L. The BOD and COD were high for most of the wastewaters. Bacteria isolates were detected in all samples with population ranging from 3.0 x 104 cfu/mL to 2.7 x 1012 cfu/mL, while fungi was averaged at 7.0 x 105 cfu/mL and total coliform was between 2.6 x 102 to 2.7 x 107 cfu/m...
Cassava, a staple crop in Nigeria, processed by numerous factories in rural and sub-urban locatio... more Cassava, a staple crop in Nigeria, processed by numerous factories in rural and sub-urban locations is known to contain some level of cyano compounds. Lack of stringent environmental regulations on management of cassava wastewater (CWW) from cassava processing factories had led to its indiscriminate discharge on the environment. CWW samples were obtained from cassava processing factories from selected states (Lagos (A), Oyo (B), Ogun 1 (C1), Ogun 2 (C2) and Cross River (D)) in Nigeria to determine the cytotoxic and genotoxic effects of extracted cyanide from the wastewaters. The cyanide was hydrolyzed via chemical degradation utilizing 1.25 M NaOH and subsequently titrated using silver nitrate with p-dimethylaminobenzalrhodamine as indicator. Further, in order to explore the potential toxicity of this pollutant present in the effluent, a battery of short-term biological assay (Allium cepa chromosomal aberration test) was used. Bulbs with roots of Allium cepa L. were treated with different concentrations (0.05%, 0.1%, 0.2%, 0.4%, and 0.8%) of CWW, and after 48 h the root tips were processed for cytological studies by the aceto-orcein squash procedure. The results revealed that cyanide concentrations on re-fluxing were in the range of 1.0 mg/L and 1.3 mg/L. All concentrations induced a number of chromosomal aberrations in the root tip cells. The mitotic index decreased significantly (p < 0.05) with increasing concentration. The cytotoxic effects showed strong concentration dependent root growth inhibition with EC50 values of 30, 20, 37, 43 and 22 % for A, B, C1, C2 and D, after 72 h. The findings thus indicate that alkali treatment is very efficient in degrading the cyanide content of CWW and has shown that the combination of physico-chemical analysis along with the sole toxicity assessment could provide valuable information about the sole toxicity of cyanide as a chemical pollutant present in the cassava effluent.
International Journal of Environmental Analytical Chemistry, 2020
The quantitation of nutrient species in the saline water of the Lagos Lagoon was carried out usin... more The quantitation of nutrient species in the saline water of the Lagos Lagoon was carried out using flow injection analysis (FIA). Due to the Schlieren effect (SE), occasioned by the formation of fr...
International Journal of Environmental Analytical Chemistry, 2020
The quantitation of nutrient species in the saline water of the Lagos Lagoon was carried out usin... more The quantitation of nutrient species in the saline water of the Lagos Lagoon was carried out using flow injection analysis (FIA). Due to the Schlieren effect (SE), occasioned by the formation of fr...
Roadside soils were sampled from the Lagos Lagoon catchment during the wet and dry seasons over t... more Roadside soils were sampled from the Lagos Lagoon catchment during the wet and dry seasons over the period 2005-2009. Lagoon sediment samples were also collected within the same period. All samples were digested with aqua regia to determine total phosphorus and extracted with 0.5 M sodium bicarbonate to determine the bioavailable fraction (Olsen-P). A segmented flow analyser method was used for analysis and good accuracy was demonstrated for two reference soils (SO-2 from CCMET and SRM 2711 from NIST). The Lagos Lagoon is a hypereutrophic water body (1270 ± 1170 μg P L(-1)), with significant areas of anoxia and water hyacinth growth. The total phosphorus concentrations in roadside soils (16 sites; mean ± 2 S.D.) were 285 ± 279 mg kg(-1) in the wet season and 424 ± 629 mg kg(-1) in the dry season, indicating that rainwater leaching is a major source of phosphorus in the lagoon. The bioavailable fractions were 5.17 ± 3.47 mg kg(-1) (2.1 ± 1.5% of the total) in the wet season and 13.0 ± 8.7 mg kg(-1) (4.3 ± 4.5% of the total) in the dry season.
Sub-Saharan Africa is seeing rapid urbanization, with the population of cities such as Lagos and ... more Sub-Saharan Africa is seeing rapid urbanization, with the population of cities such as Lagos and Nairobi growing at a rate of 3–4% a year. The region is extremely under-sampled for all air pollutants, particularly VOCs, which are useful markers for source apportionment as well as toxic in their own right. There are many contributors to air pollution in the region, and studies examining fine particulate pollution implicate traffic as the primary source in urban areas. In this pilot study, VOCs were analysed at a selection of roadside and urban background locations in Nairobi and Lagos, and 74 VOCs were quantified. GC×GC–MS/FID analysis revealed all locations were dominated by hydrocarbons typical of vehicle emissions, with the aromatic hydrocarbons benzene and toluene among the most abundant VOCs. Typical personal exposure scenarios for citizens of the cities were calculated to far exceed those of a resident in a city in Europe/US. Finally, the calculated ozone forming potential of t...
Surface water pollution has been found to be considerably driven by the contributions of airborne... more Surface water pollution has been found to be considerably driven by the contributions of airborne particles, open-air waste burning and fossil fuel combustion, ammonia volatilization from excreta, fertilizer and derivatives from explosive factories. Atmospheric deposition into the Lagos Lagoon is suspected to be a major contributor to the nutrient levels of the lagoon. Atmospheric dry nutrient deposition was monitored at six stations around the Lagos Lagoon from January to June 2012 in order to estimate the contribution of atmospheric deposits into the lagoon&#39;s nutrient cycles. Species of phosphorus (P) and nitrogen (N) in the lagoon water were analyzed by colorimetric methods. Mean [NO(-) 3 + NO(-) 2]-N was 3.08 ± 2.10 mg m(-2) day(-1) (0.55-8.73 mg m(-2) day(-1)). The (NO(-) 3 + NO(-) 2)-N was only about 2 % of total N but [NH(+) 4 + organic]-N was approximately 38 % of total N. Particulate N was about 60 % of total N. Average total N was 144 ± 94.9 mg m(-2) day(-1) (48.0-285 mg m(-2) day(-1)). Average soluble reactive P was significantly lower than [NO(-) 3 + NO(-) 2]-N averaging about 0.12 ± 0.12 mg m(-2) day(-1). Soluble reactive P (SRP) was less than 2 % of total P but soluble organic P was about 86 % of total P. Particulate P accounted for about 12 % of total P. Average total P was 4.56 ± 10.1 mg m(-2) day(-1) (0.48-31.6 mg m(-2) day(-1)). This study shows that atmospheric deposition of nutrients into the Lagos Lagoon is taking place and this may represent a considerable proportion of the total nutrient loading of the lagoon.
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