Revista de química analítica ambiental

Ohaji Egbema is known for its oil production and exploration activities and so crops grown in this area could be contaminated. Chemical speciation was carried out on four commonly grown food crops in the area so as to determine the level of metal contamination. The samples were analyzed sequentially and the metal species in the extract determined by ASS. Results revealed that mean concentrations of all studied metals to fall within the WHO/FAO permissible limits. Significant bioavailability was observed for Pb in Okoro (0.67) and Orange (0.7). Zn showed the highest concentration and its bioavailability was highest for Okoro (12.6)>Pawpaw (7.9)>Orange (5.5)>Cassava (0.28). The sum of EDI for both adult and children exhibited similar trend with Cassava having the least value in both adult and children. Though metals showed low values of EDI, excessive consumption can have adverse effect in humans due to bioaccumulation in living system. Hazard Quotient (HQ) was highest for Pb (3.524) in Pawpaw for children while Fe (0.705) was highest in Pawpaw for adult. Generally, HQ was found to be highest in children for all the metals indicating great health risk for children. Risk associated with consuming these four fruit crops in terms of summation of RAC revealed the order of decrease to be: Okoro (1620)>Pawpaw (1021)>Orange (861)>Cassava (178). This study has shown that the consumption of these fruit crops could be a great health risk for children.

The Vulnerability of the selected boreholes to bacteriological indicators in Parts of Owerri West of Southeastern Nigeria was determined using Vulnerability Index (VI). Distances between the selected boreholes and anthropogenic activities were measured. Sampled Borehole (SBH) 3, 5, 8 did not meet the 30 m WHO STD, while defecation, bathing and washing of clothes were found within the circumference of SBH 6, 9 and 10 respectively. Total bacteria, total coliform and faecal counts were evaluated using the standard plate count method and the Most Probable Number (MPN) technique, respectively. The mean total bacteria count of the selected bore water samples ranged from 0.08-2.73 × 102 CFU that constituted between 0.59-20.31%, with the mean value of 1.34 × 102 CFU/ml, Total coliform count ranged from 6-19 MPN/100 ml constituting 4.72-14.96%, with the mean value of 12.7 MPN/100 ml and Faecal coliform count ranged from 9-21 CFU/ml constituting 7.09-14.69% with the mean value of 14.3 (CFU/100 ml) all above the WHO STD respectively. The isolated and identified bacteria include: Enterobacter sp., Alcaligenes sp., Escherichia coli, Proteus sp., Klebsiella sp., Pseudomonas aeruginosa, Acinetobacter sp., Staphylococcus aureus and Bacillus sp. accordingly. From the result of Vulnerability Index (VI) calculated and rated, the selected boreholes are highly affected by faecal count rated 0.21 within the rating of 0 signifying highly vulnerable. Furthermore, results of total bacteria a, total coliform and overall result of bacteriology using VI rating recorded 1.98, 1.02, 1.07 respectively, indicating highly resilient in rating. The vulnerability of the selected boreholes to bacteria means that, water resources in this area is not suitable for human consumption, hence water borne diseases.

Concentrations of selected heavy metals (Zn, Cu, Pb, Cd, Fe, Mn, and Ni) in surface and sub-surface sediments were studied with an attempt to establish a base-line data of their concentration in the sediments of the coastal area of Kutubdia Island, Cox’s Bazar, Bangladesh. Sediment sample of twelve different sites were collected and taken for open plate digestion technique (HNO3). The concentration of heavy metals was analyzed using Flame Atomic Absorption Spectrophotometer (FAAS). The concentration of Cu, Fe, Mn, Pb and Ni in the sediment samples was higher than the proposed Threshold Effect Level (TEL). The observed concentrations of the metals varied in different sampling sites and also in surface to sub-surface. The decreasing trend of metals were observed in surface and sub-surface sediments as Fe>Mn>Ni>Cu>Pb>Zn>Cd. Geoaccumulation Index (I-geo) indicates that the sediment in the studied stations were unpolluted (grade 0) with respect to Cu, Pb, Fe, Zn and Cd whereas concentration of Mn indicated slight pollution in three stations. Contamination Factor (CF) values showed low to moderately pollution in studied stations. The values of Pollution Load Index (PLI) for the samples collected from all the stations were found less than one, indicating perfection except one study area was the hot spot. The Enrichment Factor (EF) indicates that the metal in the sediment of studied stations were entirely from crustal minerals whereas the sources of Mn are may be anthropogenic. However, the elevated level of some toxic elements was found in this investigation alarming about the natural balance of the area. Constant monitoring of the coastal area of Kutubdia Island, Cox’s Bazar, Bangladesh is needed with a view to minimize the health risk of the population as well as the detrimental impacts on the aquatic ecosystem.

Crude oil spills on soil, leakages from pipelines, underground and surface fuel storage tanks and careless disposal and mismanagement of waste and other petroleum by-products of the society, constitute the major sources of petroleum contamination in our environment. The estimated 65,000 people of Baruwa own about 350 hand dug wells for domestic water supply; more than 200 of these wells are at present, under lock and key because of the oil seepage from leaking underground NNPC (Nigerian National Petroleum Corporation) pipeline. Water samples were collected from seven hand dug wells (Jakande, Kamilla, Baale, Shodeinde, Oyewole, Lasunferanmi and Ajayi). Jakande was the control while the rest were the contaminated wells. All the wells contained TPH and Lasunferanmi had the highest TPH while Jakande had the lowest. It was observed that after the application of KMnO4 to the water samples from the oil polluted wells, the TPH concentration reduced significantly in the laboratory. Also, the kinetics of the remediation done for the reactions followed a second order reaction with a proof of linearity of the graphs and R2 value close to unity.

Five samples of drinking water (DW) were taken from five different academic institutes of District Vehari, Pakistan which are; Sample-1 from University of Education Vehari Campus; Sample-2 from Government Post Graduate College for Women Vehari; Sample-3 from Government Post Graduate College for Women Vehari; Sample-4 from COMSATS Institute of Information Technology Vehari Campus and Sample-5 from BZU Vehari Campus. The analysis was qualitative as well as quantitative to determine the quality of DW, which is based on the determination of physico-chemical characteristics of DW samples. These physico-chemical characteristics are; pH, temperature, turbidity, alkalinity, total hardness, chloride ion estimation, color and taste. Different chemical tests and techniques were applied to determine the water quality. After that, the results obtained from these experiments indicated that Sample-2 is very polluted with large amounts of salts which cause its hardness and made it unfit for drinking purposes, because this hardness causes health diseases in humans. The Sample-3 contains large amounts of chloride ions which hardened it, as its temperature is also low. Except Sample-3, all other four samples are not much polluted and are fit for drinking. So, author recommended leaving the use of Sample-3 of water of Government Post Graduate College for Boys Vehari.

The water quality of Legedadi Reservoir, which provides more than seventy five percent of the water supplies to Addis Ababa City, is deteriorating from time and time. The reservoir has suffered water quality problems for several decades due to unacceptable changes in the odor, color and other parameters. In this study the seasonal and spatial dynamics of physico-chemical parameters of Legedadi Reservoir were investigated at monthly intervals. The study was conducted from November to August at three study Sites (represented as Sites 1, 2 and 3) in the reservoir. All physicochemical parameters were measured using standard techniques in Addis Ababa Water and Sewerage Authority, Central Laboratory. The reservoir is characterized by unusually high turbidity throughout the study period (with most values >400 NTU) mainly due to sediment influx during run off and resuspension of sediment. Secchi depth (transparency) of the reservoir was extremely shallow and (always <10 cm) and showed both seasonal and spatial variations (7.6 ± 0.6, 8.3 ± 0.9 and 8.1 ± 0.6 cm at Sites 1, 2 and 3 respectively). The pH was around neutral (7.85 ± 0.23, 7.87 ± 0.26 and 7.69 ± 0.33 at Sites 1, 2 and 3 respectively) throughout the study period at all study Sites. Both TDS and conductivity varied temporally and spatially at all locations although the conductivity and TDS values were within the range that drinking water should have. The total alkalinity was found to be low (0.84 ± 0.28, 0.8 ± 0.32 and 0.87 ± 0.26 meq/L at Sites 1, 2 and 3 respectively) resulting in high sensitivity of the reservoir even to a small change of pH. Carbonate hardness varied both seasonally and spatially with a value of 48.6 ± 6.9, 45.6 ± 8.1 and 45.3 ± 7.3 mg/L at Sites 1, 2 and 3 respectively. With regard to conductivity, TDS, pH and hardness, although there were significant seasonal and spatial variations (p<0.05), the values were within the acceptable range. However, the reservoir is characterized by unusual values of turbidity and transparency, which could be the major cause to the deterioration of the water quality of the reservoir.

This study concentrated on the physico-chemical characterization of effluents of leather industry and their reduction by filtration and coagulation processes as physical and chemical treatment. It was observed that the pH was basic and the TSS, TDS, BOD5 and COD were very high in the case of raw effluent. By adopting settling and filtration through glass wool, the effluents were somewhat treated. After that, chemical treatments were imposed upon them by using different doses of FeCl3 as coagulant and trimethyl ammonium chloride [(CH3)3NHCl] as coagulant aid. It was observed that best result was found by using coagulant (FeCl3) of 120 mg/L dose and coagulant aid [(CH3)3NHCl] 12 mg/L dose near the neutral pH. So, it could be said that tannery effluents would be treated by following a combination process of settling, filtering and coagulating with FeCl3 and [(CH3)3NHCl].

The agricultural soil or land is fertilized using fertilizers (natural or synthesized). Synthesized ones may be effective in the beginning but later have side-effects on the crop. Bio-fertilizers or natural ones are mostly used but they cannot sustain the fertility of the soil for longer periods. This can be solved by adding charcoal to the soil. As charcoal is one of the purest forms of carbon, it helps in sequestering the carbon captured from carbon dioxide emissions thereby retaining the quality of soil. It helps the bound and clumped ions to dissociate and move freely all through the soil. This solution was found by some of the researchers in the recent years. As we know, the charcoal could be the decay of anything. Researchers have found a new method to sustain the fertility of the soil for a long time. That is by using biochar instead of the random charcoal. Biochar is the form of charcoal that is only produced from plant organic matter which helps in absorbing carbon dioxide (CO2) from the air and fertilizing the crop.

New polymers polypiperazines were synthesized in the presence of a non-toxic catalyst Maghnite-H+ from the addition of dihalogenated compounds such as 1,6-dichlorohexane and 1,2-dibromopropane to piperazine, after the comparative study of the polymerizations without and with this catalyst. The yields of the synthesis induced by Mahgnite-H+ are high compared with those of the uncatalyzed reactions. In our case, the effect of reaction time on the yield was studied by carrying out a series of experiments by maintaining the quantities of the reagents and varying the time t. On the other hand, polymerizations of piperazine are realized by maintaining the amounts of monomer, the time duration and varying the amount of Mahgnite-H+ in order to control the influence of the amount of this catalyst on the yield of the bulk polymerization of the piperazine. By constation, the yield grows either with the increase of reaction time, or by increasing the quantity of the catalyst. All products synthesized during the addition of dihalogenated compounds to piperazine were characterized by FT-IR spectroscopy (Perkin Elmer System), 1H-nuclear magnetic resonance (NMR) and 13C nuclear magnetic resonance (NMR) measurements were carried out on a 300 MHz Bruker NMR Spectrometer.

Copolymers of maleic anhydride and styrene were synthesized by block-radical polymerization. The structures of cross-linked copolymers were determined by IQ-spectroscopy. Based on the obtained structure, the shape of crosslinked copolymer, which was used as a sorbent and the structure of uranyl-ions which is in hydrated form in water solution forms the chelating structure due to free electron pair of nitrogen, oxygen and recoverable ions. Detection of the best conditions of sorption of uranyl-ions by cross-linked copolymer was carried out in the experiments by varying pH at different time intervals.