The Effects of Native Plant Species Vegetated in Constructed Wetland on Removal of Selected Pollutants in Water of Bomachoge Sub County in Kisii County-Kenya

The relationship between water quality and health should be appreciated by engineers and researchers so that water resources users can be sensitive to water contamination and associated health impacts. It’s against this background that this study was carried out to establish the quality of water before and after passing through vegetated constructed wetlands. This is presumably a less costly method of naturally reducing pollutant load in water sources. This study evaluated the levels of microbial and chemical parameters of water in surface flow through constructed wetlands vegetated with Colocasia esculenta, Cyperus esculentus and their combination to determine the efficacy of plant species in removal of these parameters. The study was conducted from August 2015 to February 2016 at Bomachoge Sub County of Kisii County, Kenya. Measurements and laboratory examinations of water samples was carefully done and results revealed that there was significant (p<0.005) removal of all selected parameters, whereby Colocasia esculenta was more effective than Cyperus esculentus and their mixture. C. esculenta (A), C.esculentus (B) and their combination (AB) removed selected  bacteriological parameters such as faecal coliforms by (A 98%, B 16%, AB 36%), faecal Streptococcus (A 100%, B 13%, AB 15%), total coliforms (A 98%, B 18%, AB 26%) and Escherechia coli (A 97%, B 11%, AB 34%) and physico-chemical parameters such as, dissolved oxygen increased by (A-244%, B-318%, AB -107%) conductivity removed by (A 65%, B 41%, AB -28%), phosphates (A 95%, B -20%, AB 37%), nitrates (A 86%, B -38%, AB 40%) and turbidity (A 65%, B 67% AB -19%)  from the result DO increased significantly. These results show that C. esculenta performance was higher compared to C.esculentus and the mixture of both plants, however, the combination of two plant species performed better than C. esculentus. Statistica statistical program was used to compare the overall, among and within samples. From the findings it shows that both plant species significantly removed pollutants from water. It was recommended that C.esculenta and C.esculentus plant species to be conserved and more studies to be done on other native species in other places of kisii county to ascertain their efficacy in water purification. Keywords: Faecal, Contamination, Anova, Parameters, Coliforms, Wetland, Bacteriological

Composition-structure-property effects of antimony in soda-lime-silica glasses

Float glass-type SiO 2-Na 2O-CaO glasses with 0 – 10 mol% Sb2O3 were melted and their compositional, structural, thermal and optical properties characterised. All glasses were X-ray amorphous and increasing Sb2O3 content progressively decreased glass transition temperature (Tg) and dilatometric softening point (T d), despite increases in Al2O3 content from greater crucible corrosion. 121Sb Mössbauer spectroscopy confirmed that Sb was predominantly incorporated as Sb 3+ (Sb 3+/ΣSb ~ 0.9) and Raman spectroscopy showed that Sb substantially decreased average (Si, Al)-O Qn speciation. Both techniques confirmed that Sb3+ ions were incorporated in trigonal pyramidal [:SbO 3] polyhedra. XRF and Raman spectroscopies confirmed that SO 3 content decreased with increasing Sb2O3 content. TGA analysis showed, as a linear function of Sb2O3 content, mass gain commencing at 700°C, reaching a maximum at 1175°C, then mass loss above 1175°C, consistent with oxidation (Sb3+ → Sb5+) then reduction (Sb5+ → Sb3+). The TGA samples were shown to have attained or approached Sb redox equilibrium during measurement. Optical absorption spectroscopy (UV-Vis-nIR) showed red-shifts of the UV absorption edge with increasing Sb 2O 3 content, consistent with increasing intensity of far-UV absorption bands from Sb3+ and Sb5+ s→p transitions. UV-Vis-nIR fluorescence spectroscopy evidenced a broad luminescence band centred at ~25,000 cm−1, attributed to the 3P 1→ 1S 0 transition of Sb 3+, which is Stokes shifted by ~15,000 cm −1 from the 1S0→ 3P1 absorption at ~40,000 cm−1. The most intense emission occurred at 0.5 mol% Sb 2O3, with concentration quenching reducing luminescence intensities at higher Sb 2O3 contents. Additions of Sb2O3 to float-type soda-lime-silica glasses could thus enable lower melting energies and/or new solar energy applications