An Investigation of the Synergystic Effects of Titanium (Iv) Oxide Modified Clay in Disinfection and Purification of Water

Abstract

Access to potable water is a problem facing developing countries worldwide. This water problem is expected to worsen with the population increase in the developing countries. It is in view of the water crisis that a series of research studies have been conducted with sole aim of alleviating the problem and coming up with a cost effective point of use water treatment method. This study was carried out to assess the effectiveness of titanium (iv) oxide (TiO2) modified clay in water purification. Clay soils were collected from Kenyatta University, department of ceramics and Got Ramogi, in Thika and Bondo sub-counties respectively. Chemical compositions of the two clay samples were determined by X-ray fluorescence (XRF) machine. Titanium (iv) oxide (TiO2) used was DEGUSSA P25 and calcination was done in an oven. The calcination temperature was 600oC. Methyl orange was degraded by TiO2 to determine its photocatalytic activity. The residual concentration of the degraded methyl orange was determined using UV spectrophotometer, model Shimadzu pharmaspec UV 1700. The ceramic filter was coated with TiO2. Water samples used in the analysis of physico-chemical parameters and E. coli were collected from Usenge beach in Bondo sub-county and Nairobi River in Nairobi county. Triple distilled water was spiked with different concentrations of copper and lead salts then filtered. A measured concentration of organochlorine pesticides mixture was spiked in triple distilled water then filtered. Analyses of various parameters were done on the water samples before and after ceramic filtration to determine the efficiency before subjecting the filters to field sample analysis. Parameters analyzed include turbidity, pH, TSS, TDS, E. coli, pesticides and heavy metals. E. coli analysis was done by transferring the sample to a 3M test kit, then incubating at 37.2oC for 24 hours. Heavy metal analysis was done using Atomic Absorption Spectroscopic machine model Spectra AA.10. Labtec. Pesticide extraction was done using Solid Phase Extraction cartridge from Superlco Analytical TM U.S.A and analysis was done by gas chromatography mass spectroscopy machine of model Varian Cp 3800 GC/MS. Results showed that TiO2 modified clay filter reduced turbidity from 24.667± 0.0577 NTU to 0.0212 ± 0.0016 NTU.TSS in water were reduced by filters from 276 ± 14.730 mg/L to 1.00 ± 0.328 mg/L. The filtered water had E. coli colonies reduced from 4310.83 ± 15.718 c.f.u/100ml to 0.00 c.f.u/100ml, the modified clay filters reduced up to 1000ppm of lead and copper to below detection level. OCP pesticides in water were all reduced by the filters to below detection levels except δ-HCH which had residual 390 ± 108.45 ng/l out of the initial 2512.479 ng/l. Improved efficiency of the TiO2 modified filters was noted in their enhanced ability to reduce the contaminant levels in water.