Browse

You are looking at 1 - 10 of 644 items for :

  • Chemistry, other x
Clear All
Open access

Faith Iguodala Akinnibosun and Abigail Ashegbare

Abstract

This study was aimed at isolating and characterizing hydrocarbon-degrading fungi from hydrocarbon-contaminated soil in Ogbe-Ijoh oil creek in Warri, Delta State, Nigeria. Isolation and characterization were carried out using standard methods. Biodegradation assay was carried out over 25 days and monitored using the following parameters; pH, total organic carbon, and total hydrocarbon content. The fungi isolated were: Penicillium sp., Aspergillus niger and Fusarium sp., and these were used for the biodegradation study. Physico-chemical analysis of the crude oil contaminated soil during degradation showed that there was significant decrease in pH during degradation from day 10 - 25 (p ≥ 0.05). This showed the ability of the fungal isolates to utilize crude oil as carbon source, producing acid during its metabolism. The highest pH value during degradation by the fungal isolates was recorded in Fusarium sp. and the lowest was recorded in Aspergillus sp. The fungal isolates were able to reduce the total carbon and hydrocarbon content during degradation. This was probably due to the utilization of the nutrients in the soil sample as energy source. The results from this study indicate the potential of the isolated fungi for hydrocarbon bioremediation activity.

Open access

Faith Iguodala Akinnibosun and Adedayo Michael Oyetayo

Abstract

In this study, cashew apple residue (CAR) was subjected to various treatments (boiling, soaking and fermentation), thereafter, proximate composition and anti-nutrient content were determined. Fermentation significantly (p < 0.05) increased the protein content of the CAR by 56.07% and reduced the carbohydrate content to 42.49%. Moreover, soaking and fermentation significantly reduced phytate content of the CAR from 0.4123% to 0.2504% and 0.1106% respectively; all the treatments significantly reduced the oxalate content while boiling and soaking had a significant reducing effect on the tannin content of the CAR. These suggest that pre-treated cashew apple residue may be used for animal feed formulation.

Open access

Shashidhar N. Adarakatti, Veeresh S. Pattar, Prashant K. Korishettar, Bhagyashri V. Grampurohit, Ravindra G. Kharabe, Akshay B. Kulkarni, Shridhar N. Mathad, Chidanandayya S. Hiremath and Rangappa B. Pujar

Abstract

Li-Ni ferrite has gained great scientific elicit owing to of its unparalleled properties and applications. The copper doped Li-Ni ferrite has been synthesized by sucrose method. The structure was characterized by X-ray diffraction, which has confirmed the formation of single-phase spinel structure. X-ray diffraction and FTIR data reveals the formation of cubic structure phase. Unit cell parameters vary with copper content; overall variation of the unit cell parameters obeys Vegard’s law. The main absorption bands of spinel ferrite have appeared through IR absorption spectra recorded in the range of 300–700 cm−1. The copper concentration dependence of lattice parameters obeys Vegard’s law. DC electrical resistivity of the prepared samples decreases with increasing in the temperature which shows the semiconducting behaviour of all nano ferrites. The most prominent influence copper doping on the electrical properties of Li-Ni ferrites has been reported.

Open access

Ceylan Hepokur, Hesna Nursevin Öztop and Dursun Saraydin

Abstract

In this study, molecular imprinted polymers for highly selective recognition of cholic acid, which is a bile acid, were prepared. Acrylamide, methacrylic acid, methacrylamide were chosen as monomer for the production of molecularly imprinted polymers. Functional monomers were polymerized with various crosslinkers; ethylene glycol dimethacrylate (EGDMA), 1,4-butanediol diacrylate (BUT), trimethylpropane triacrylate (TMT) with target molecule (MIP-EGDMA, MIP-BUT and MIP TMT) and various MIPs were prepared. The cholic acid was removed from MIP with a suitable method. NIP polymers were synthesized without cholic acid (NIPEGDMA, NIP-BUT and NIP-TMT). For the characterization of synthesized polymers FTIR, DSC, TGA, SEM analyses were used. The parameters that affect the adsorption of target species on polymers such as temperature, pH, and concentration were evaluated. The selectivity and reusability studies were also investigated.

It is concluded that MIPs showed better adsorption capacity than NIPs for all solvents for cholic acid. The adsorption sequencing is MIP-TMT > MIP-BUT > MIP EGDMA. The maximum adsorption achieved with ethyl alcohol. The adsorption of cholic acid varies with chancing pH for all produced MIPs and NIPs. It is concluded that the adsorption of cholic acid is not affected by the temperature. The adsorption of cholic acid is followed as L type from Giles adsorption isotherms. The thermodynamic parameters are proved the physical nature of adsorption process. The studies conducted with deoxycholic acid, taurocholic acid that is homolog to cholic acid showed that produced MIPs are highly selective for cholic acid.

Open access

Cong Tien Nguyen, Ha Manh Bui and Duyen Hoang My Nguyen

Abstract

The A new benzothiazepine’s derivative names N-(p-tolyl)-2-(2-(4-phenyl-2,3-dihydrobenzo[b][1,4]thiazepin-2-yl)phenoxy)acetamide was synthesized by reaction of o-aminothiophenol and N-(p-tolyl)-2-(2-(3-oxo-3-phenylprop-1-en-1-yl)phenoxy)acetamide, which was prepared from salicylaldehyde and acetophenone through (E)-3-(2-hydroxyphenyl)-1-phenylprop-2-en-1-one. The structures of the compounds were determined by IR, 1H-NMR, 13C-NMR and HR-MS spectral data.

Open access

Fatemeh Rigi and Hamid Reza Shaterian

Abstract

Silica ammonium acetate (SiO2-NH4OAc) was applied as an inexpensive, practical and heterogeneous catalyst for the preparation of new and known dihydropyrazolo[4',3':5,6]pyrano[2,3-d]pyrimidine-5,7-diones via one-pot four-component reaction of hydrazine hydrate, ethyl acetoacetate aldehydes and barbituric acid/dimethyl barbituric acid under solvent-free conditions. Silica supported ammonium acetate (SiO2-NH4OAc) was prepared according to easy procedure under ambient condition. After completion of the reaction, the catalyst was separated by filtration and reused. So, recycling system, simple work-up, using non-toxic materials, excellent yields and short reaction times makes our research green and convenient for preparation of these classes of organic compounds.

Open access

Pavel Anatolyevich Nikolaychuk

Abstract

Thermodynamic properties of lead species in aqueous solution are collected. The chemical equilibria between various forms of Pb(II) are considered. The speciation diagrams for the equilibria 4[PbOH]+(aq) ⇄ [Pb4(OH)4]4+(aq) and 2[Pb3(OH)4]2+(aq) ⇄ [Pb6(OH)8]4+(aq), and the thermodynamic activity - pH diagram of Pb(II) species are plotted. Basic chemical and electrochemical equilibria for lead are calculated. The potential - pH diagram for Pb - H2O system is revised.

Open access

Mensur Kelmendi, Milaim Sadiku, Sadija Kadriu, Florent Dobroshi, Liridona Igrishta and Blerim Baruti

Abstract

For the first time, a survey about agricultural land focusing on the partitioning of the Pb, Cd, and Zn to the rural part of Mitrovica in northern Kosovo was made. Kosovo’s Mitrovica is one of the main industrial sites in the former Yugoslavia and a world-class mining district in Europe. The process of obtaining metals dates since 1927. From this year until 2000, the technological process of acquisition/obtaining has been accompanied by environmental pollution by creating waste landfills. These landfills are located on the outskirts of the city of Mitrovica at a distance from 1 to 4 km. In this area high levels of heavy metals in air, water, and earth were noticed. Therefore, these metal residues have a particular impact on air, earth, water, and effects on plants, animals and humans health. This situation became alarming; therefore in 2000 the production process was discontinued. During the period from 2000 to the present day, there is noticed a change of nature. Residents of the area have begun to work on agricultural lands without realizing the potential risk coming up. Despite the stagnation of industrial production, environmental pollution continues even further, especially from the landfill generated by industrial wastes. Widespread and very visible contamination mainly from Pb, Zn, Cd were found on the ground, with the highest concentrations measured near the Zveçan smelter. A significant amount of Cd, Pb, and Zn in contaminated soils/ground was quite movable/changeable, suggesting that these elements may be readily available for plants and soil/ground organisms. The main objective of this work is to address this pollution and take measures for education and information.

Open access

Emmanuel N. Agomuo and Peter U. Amadi

Abstract

This investigation was carried out to assess the heavy metal concentrations and health risks associated with automobile workshops in Owerri Metropolis. Using an Atomic Absorption Spectrophotometer, soil samples from Orji Mechanic Village (OMV), Naze Mechanic Village (NMV), New Market Automobile Workshops (NMAV), Matrix Mechanic Yard (MMY) and Alvan Mechanic Yard (AMY) were assayed for Silver (Ag), Cobalt (Co), Nickel (Ni), Mercury (Hg), Lead (Pb), Arsenic (As), Chromium (Cr) and Cadmium (Cd) concentrations. The result showed that at majority of the sites, the Ag, Pb, As, and Cd levels exceeded their baseline values, whereas the Ni and Co levels were equivalent to those of their baselines, at some sites. Soil samples at MMY were the most acidic while that of NMAV was the most alkaline. The pollution models indicated very high Ag contamination at OMV, NMV, and NMAV while all the sites showed very high contamination of Pb and Cd, and no Co, Ni, Hg, and Cr pollution was recorded for all the sites as shown by their Igeo values. The result for the enrichment factor showed anthropogenic sources of deposition of these heavy metals at all the sites. From the risk assessment models applied, none of the contaminated sites showed an estimated daily intake, hazard quotient, and total hazard index beyond the reference values, with Pb found to possess the greatest potentials of toxicity. This study has shown the necessity to periodically monitor and apply measures that can halt the environmental decay, occurring at the automobile workshops.