Open Access Original Research Article

Heavy Metals Contamination and their Potential Toxicity in Petroleum Sludge Impacted Soils from Itsekiri Communities, Delta State, Nigeria

Useh Mercy Uwem, Dauda Mary Sunday

Chemical Science International Journal, Page 1-15
DOI: 10.9734/CSJI/2018/42973

The concentrations of some heavy metals (Chromium, Cadmium, Lead, Nickel, Copper, Cobalt, Manganese, Iron and Zinc) in petroleum sludge impacted soils were determined to evaluate their contamination levels using atomic absorption spectrophotometer.  The petroleum sludge samples were collected from the discharge pit of Warri Refinery and Petrochemical Company (WRPC)  while the  soil samples were collected from five selected oil-impacted communities (Ubeji – 500 m, Ekpan – 1.5 km, Aja-Etan – 2.5 km,  Ifie-Kporo – 3.0 km, Ijala-Ikenren – 3.8 km from Warri refinery and were coded A, B, C, D and E respectively). A control sample was also collected 8.5 km away from the refinery. The results obtained revealed that with the exception of Fe, the sludge samples contained the highest concentrations (in mg/kg dry weight) of Chromium (2462.6±0.5), Lead (406.7±0.2), Copper (201.3±0.0), Manganese (8335.1±0.9) and Zinc (1009.2±0.3) while Iron was highest (10313.5±2.3) in site A. All the metals were higher in the studied sites than the control sites and a stepwise decrease in metal contents were observed from A to E. Some geochemical assessment techniques, including enrichment factor (EF) and geoaccumulation index (Igeo), were used to determine the levels of metal toxicity in the sediments. Computed enrichment factors showed that the soil samples have suffered significant systematic heavy metals enrichment following proximity to the refinery. Values of geoaccumulation index (Igeo) indicated different contamination and toxicity levels of Chromium, Cadmium, Lead, Copper, Manganese, and Zinc while Nickel was not detected.

Open Access Original Research Article

Concentration Levels of Iron (Fe), Copper (Cu), Lead (Pb), Cadmium (Cd), Chromium (Cr) and Selected Nutrients in Water of Motoine River Channel, Kibera, Kenya

S. M. Muthee, A. M. Salim, A. O. Onditi, A. O. Yusuf

Chemical Science International Journal, Page 1-8
DOI: 10.9734/CSJI/2018/43319

The need for clean and safe consumable water is of paramount importance to any society since water is a crucial substance for the sustenance of life. Kibera slum is one of the leading slums in the world with a high population, leading to poor levels of sanitation and inadequate clean water supply. Consequently, the residents have to seek for alternative water supply. Motoine River flows through the slum, and thus acts as an alternative source of water. This study determined the concentration levels of heavy metals (Pb, Fe, Cu, Cr and Cd) and nutrients (nitrates, nitrites and phosphates) in Motoine River, Kibera in September 2014 and compared the variations downstream. The metals were determined using Atomic Absorption Spectroscopy (AAS) while the nutrients were determined using UV/Visible spectroscopy. Concentration levels of Cu, Cd and Cr were found to be lower than the Environmental Protection Agency (EPA) values for maximum contaminant level (MCL) while those of Fe, Pb and the nutrients were higher than EPA’s MCL values. Cd had the lowest concentration and was below the detection limit of the instrument used. Nitrates were found to be of the highest concentration at 16.4959 ± 2.4432 parts per million (ppm). The high concentration of nutrients in the water could be due to domestic waste and effluent disposal into the river and agricultural runoffs while that of metal ions could be due to waste from informal jua kali industries and erosion of natural deposits. The efforts by the government to rehabilitate and clean rivers within Nairobi should be extended to include Motoine River.

Open Access Original Research Article

Proximate and Chemical Characterization of Ocimum gratissimum Plant Grown Using Different Manure

T. T. Adebisi, O. S. Oyadeyi, S. A. Okewole, L. O. Oyekunle, O. O. Akande

Chemical Science International Journal, Page 1-10
DOI: 10.9734/CSJI/2018/42967

The proximate, minerals, and phytochemical composition of Ocimum gratissimum plant (OGP) that grew with different manure were investigated. OGseeds were planted in experimental plots in a Randomized Complete Block Design (RCBD) laid out in Oyo State College of Agriculture, Igboora  with three replicates having plot size 3 m x 3 m of four treatments namely; Treatment A-No fertilizer or manure -(control), B- Poultry manure, C- N:P:K 15:15:15 and D-Compost manure respectively. Other parameters studied were planted height, leave areas, number of leaves and plant girth. The pre-soil test carried out indicated that the soil had organic matter (OM) content of 1.56%, total N 0.11% and available P 16.92 mg/g. This low level of nutrients justified the need for fertilizer application for maximum production. It could be concluded that there was significant (p<0.05) differences in other parameters considered from 3 to 9 Weeks After Planting (WAP) on all the agronomic characters. Furthermore, the proximate and minerals of the OGP went in favour of Compost raised OGP with highest values of significance. Followed by Poultry manure plant while N: P: K and No-manure treatments had the least (P>0.05) values respectively. The phytochemicals of the OGP which include Alkaloid, Flavonoid, Saponin and others were also high (P<0.05) in values on Compost and Poultry manure and the least value were observed in N. P. K and Control plants.

Open Access Original Research Article

Сomposition and Rheological Properties of Decomposition Products of Low Grade Phosphorite with Phosphoric Acid

Umarbek Alimov, Shafoat Namazov, Akhmed Reymov

Chemical Science International Journal, Page 1-11
DOI: 10.9734/CSJI/2018/25653

The investigations’ results of composition and rheological properties (density and viscosity) of reaction mass – calcium-phosphate and acid monobasic calcium phosphate’s slurries which were obtained at temperature 30-100°С have been given in this study. Chemical composition of calcium-phosphate and acid monocalcium phosphate slurries were found out. It was established that the decomposition products of low grade phosphorite from the Central Kyzyl kum deposit with phosphoric acid (35.69, 41.2 and 44.98% Р2О5) have successful flowing in the determined temperatures. Density and viscosity of slurry were studied depending on the concentration and the norm of the phosphoric acid and the temperature from 30 to 100°С. It was shown that in investigation have ranges of parameters the rheological characteristics of slurries will successfully flow with exciting installations in the industrial conditions.

Aims: The investigations of composition and rheological properties (density and viscosity) of reaction mass, calcium-phosphate and acid monobasic calcium phosphate’s slurries.

Study Design:  Determination of total and water soluble forms of phosphorus (P2O5tot., P2O5wat.) was performed on KFK-3 (l = 440 nm) as phosphorus-vanadium-molybdenum complex. This method is based on measuring the light transmission of yellow phosphorus-vanadium-molybdenum complex relative to the reference solution containing a certain amount of phosphates. The concentration of the free form of phosphorus (P2O5tot.) was determined by potentiometric method on ionomer I-130M (Russia). Determination of CaO and MgO carried out by volume of complexometric titration of 0.05 N solution of EDTA in the presence of calcein indicators and chrome navy. The content of the total form SO3 (SO3tot.) was by gravimetric, precipitation as barium sulphate. The concentration of free of SO3 (SO3free.) was determined by back titration alkaline solution (0.1N NaOH solution) in the presence of phenolphthalein indicator methyl red. Analysis on Al2O3 and Fe2O3 were carried out by complexometric method. The density was determined by pycnometric technique, and its viscosity –using viscometer grade of VPJ-2 with a capillary diameter of 1.47 and 2.37 mm. The density and viscosity were determined at temperatures from 30 to 100 ° C in a thermostat filled with glycerol.

Place and Duration of Study: Laboratory of phosphate fertilizers of the Institute of General and Inorganic Chemistry under Academy Science of the Republic of Uzbekistan, in July 2015.

Methodology: Decomposition of phosphate Central Kyzylkum with evaporated wet-processing phosphoric (WPA) was carried out in a thermostated glass reactor (500 ml) which is equipped with screw stirrer for 60 min. at 95°C. Norm of WPA was 200, 250, 300; 300, 400, 450, 500 and 400, 450, 500, 550, 600% for CaO in the raw material. After decomposition process of phosphorite the resulting slurry consists of the liquid and the solid part of the complex dispersed system which are the structured and unstructured suspensions of the dispersed phases. The content in the reactor was divided into two parts: the first part of the pulp suspension was left the calcium phosphate for further the study, while the second part is separated into solid and liquid phase by filtration. The filtered liquid phase was subjected to cooling at 40°C for 2 hours to isolate crystals of a monobasic calcium phosphate (MCP) by a laboratory centrifuge mark OPN-8 (Russia).

Results: The rheological properties (the density and the viscosity) of the calcium phosphate and acid MCP slurry were high when lower norm, and higher concentration of WPA. However, with increasing temperature, the density and the viscosity markedly decreased. It can be seen that on the rheological properties significantly affect the concentration of WPA and temperature. However, the increase of the norm at the same temperature and the concentration of WPA, there viscosity and the density are significantly reduced. Thickening of the acidic MCP was observed at certain temperatures during the experiment, indicating that the crystallization of the components of the metal-phosphate in one. Also, the higher the norm and lower the concentration of WPA, the lower the figures.

Conclusion: In all cases, the increase of temperature, higher norm of acid, lower concentration of acid lead to decrease of the rheological properties.

Open Access Original Research Article

Adsorption of 2,4-dinitrophenol on Activated Carbon Prepared from Cotton Cakes: Non-linear Isotherm Modeling

Bopda Aurelien, Tchuifon Tchuifon Donald Raoul, Nche George Ndifor-Angwafor, Kamdem Tamo Arnaud, Anagho Solomon Gabche

Chemical Science International Journal, Page 1-20
DOI: 10.9734/CSJI/2018/43499

In this research, cotton cake has been investigated as a cheap and available precursor used for the production of novel carbon using phosphoric acid and potassium hydroxide as chemical activating agents with 2:1; 1:1, impregnation ratio at various concentrations of 0.5M; 1M; 1.5M using the batch adsorption mode to 2,4-dinitrophenol. Carbonization was performed at 450oC for one hour and allowed to cool. The KOH activated carbon has exhibited high Iodine number values ranging between 447 and 590 mg/g. Thus, KOH was the activating agent in our study and the best ratio was used for the continuation of our work. The activated carbon was characterized by Fourier transform-infrared (FTIR) spectroscopy, scanning electron microscopy (SEM) and proximate analysis (pHZCP, pH, bulk density, moisture content, ash content, volatile mater, fix carbon content and matter soluble in water).The experimental isotherms were analyzed using two, three and four parameter sorption isotherm models. Three errors analysis methods were used to evaluate the experimental data: correlation coefficient (R2), Chi-square (χ2), Average Relative Error (ARE), Sum of Absolute Errors (EABS) and Root mean square error (RMSE) values were tested to find the best fitting isotherm. According to chi-square test (X²), it appears that the Freundlich (two parameters), Hill (three parameters) and Marczweski-Jaroniec (four parameters) models describe better the adsorption data.