Chemical Science International Journal

Introduction: The constant impact on the environment occasioned by pollution, indiscriminate application of agricultural chemicals, security challenges and crisis in the Niger Delta ecological area of Nigeria has caused severe damage to plants, soil organisms and humans.

Aim and Methodology: In this research, onions (Allium cepa L) was exposed to varying concentrations of an atrazine-based selective herbicide Arda-force® to estimate the phyto-toxic effects on the plant species using the Organization for Economic Co-operation and Development, (OECD) protocol #208.

Results: The mean effective concentration (EC₅₀) using root growth inhibition produced indications of phyto-toxicity to the exposed species at a concentration of 0.55 ± 0.06 mg/L. Similarly, the maximum root growth inhibition efficiency relative to the control was 65% as recorded in the highest test concentration of 1.25 mg/L.

Discussion: The study indicated that constant application / indiscriminate use of the herbicide Arda-force® could cause deleterious influence on these plant and vegetable species, daily consumed by humans as a rich source of anti-oxidants.

Conclusion: This study concluded that atrazine-based herbicide Arda-force® used in this assessment resulted in phyto-toxic effects to Allium cepa L. At the exposed concentrations of the herbicide to non-target specie – Allium cepa L. that are integral parts of the ecosystems, the ‘‘harmless’’ status of atrazine acclaimed by the United State Environmental Protection Agency (USEPA) is still very much in doubt.

Grätzel cells mimic the process of plant photosynthesis, and these new dye-sensitized cells take the imitation even closer, the new chemical combination gives them a greenish tint. Pt/TiO₂/Dye modified electrode shows two pair of oxidation peaks at 256 and 474 mV which is ascribed to Fe³⁺/Fe²⁺ and a reduction peak of 210 mV which is ascribed to TiO₂/Dye. The internal resistance of the DSSC shows the dye can be strongly adsorbed to the surface of TiO₂, therefore Pt/TiO₂/Dye electrode transfers electron with very minimal resistance making the dye a good sensitizer material for DSSCs. The high voltage is as a result of the impregnation of the dye on the TiO₂. An investigation into the internal resistance of the DSSC shows the dye can be strongly adsorbed to the surface of TiO₂, therefore Pt/TiO₂/Dye electrode transfers electron with very minimal resistance making the dye a good sensitizer material for DSSCs.

Open dumpsites are one of the main sources of heavy metals and as a result, lots of research has been undertaken on the pseudo-total content of heavy metals in dumpsite soils, but little research on the forms in which they exist. The current research was carried out to determine levels of chromium, lead and cadmium in the various fractions of Dandora dumpsite soil and how they are fractionated in the topsoil and subsoil horizons. Samples were obtained from eight sites with depths of (0-30 cm) and (30-60 cm) for topsoil and bottom soils respectively. The modified Community Bureau of Reference (BCR) sequential extraction procedure was used and metal analysis performed using flame atomic absorption spectrophotometry. The metals (lead, chromium and cadmium) total concentration (µg/g) in the upper soil profile ranged from 42.22 to 1096.21, 38.26 to 180.60 and 11.23 to 44.22 while the lower soil profiles were 54.19 to 239.28, 30.56 to 76.48 and 9.47 to 22.56, respectively. The concentration of lead in various fractions of the upper soil profile followed the order; reducible > oxidisable > residual > exchangeable, while that of chromium was residual > oxidisable > reducible > exchangeable. Cadmium followed the order exchangeable > residual > reducible > oxidisable. The percentage of the metals in non-residual fraction were Pb (78%), Cr (58.7%) and Cd (70%). Their mobility factors were (Pb) 39.7 (Cr) 7.75 and (Cd) 5.02 in the upper soil profiles. Thus, the results suggest that Dandora dumpsite is highly polluted with the selected heavy metals.

Defined are the physicochemical properties of three mountain spring waters in the area of Vasiliovska mountain, Municipality of Teteven, Bulgaria. Vasiliovska mountain is in the central part of Stara Planina (Balkan) mountain.

The methodology is including research of physicochemical parameters and microbiological indicators. It is needed the whole parameters to corresponds to Ordinance № 9 / 2001, Official State Gazette, issue 30, and decree № 178 / 23.07.2004 about the quality of water, intended for drinking purposes in Bulgaria, European Union [1,2,3].

The spring waters from the given three water sources are characterized by microbiological indicators, and the pathogenic micro-organisms in the samples from the springs water sources mentioned above are determined by the membrane method [4,5].

It is shown that according to 18 controlled parameters included in the study, the following springs in Vasiliovska mountain - “Babintsi” with water temperature 12.3°C, “Gechovoto” with water temperature 13.5°C, “Ignatov izvor” with water temperature 14.1°C, correspond to all controlled parameters according to Ordinance № 9 / 2001, Official State Gazette, issue 30, and decree № 178 / 23.07.2004 about the quality of water, intended for drinking purposes.

The problem of ground water pollution in several parts of the country has become so acute that unless urgent steps for detailed identification and abatement are taken, extensive ground water resources may be damaged. The quality of ground water depends on a large number of individual hydrological, physical, chemical and biological factors. Generally higher proportions of dissolved constituents are found in ground water than in surface water because of greater interaction of ground water with various materials in geologic strata. The work done on ground water of Satna District covering various inorganic non metallic constituents covered are pH, TS, TDS, TSS, TH, DO, BOD, COD, Alkinity, Conductivity.