Introduction:In this study, a side-by-side comparison was performed to examine the effects of nano-TiO2(nT) on the photocatalytic activity of Portland cement (PC) mixtures and its effectiveness compared to similar replacement percentages of micro-TiO2(mT), both of which were 100% anatase.Methods:Cement paste specimens were prepared by progressive cement replacement with nT or mT. To simulate the effect of humidity in different seasons, the PC specimens were subjected to different moisture conditions, including normal conditions with 50% Relative Humidity (RH), saturated conditions with 100% RH, and oven-drying conditions with 0% RH. Their photochemical reaction (i.e., gas removal ability) with TiO2was evaluated and compared with the control specimens. Furthermore, the self-cleaning ability of the mixtures was examined by applying a drop of methylene blue dye to the specimen surface; differences in dye discolouration with time under different illuminations were noticed.Results and Conclusion:This paper describes the results of an attempt to understand the effect of humidity on the photocatalytic performance of PC composites that incorporate TiO2. The results show that PC mixtures modified with nano titanium are more effective in hot and dry conditions. In contrast, micro titanium mixtures appear to be favourable for wet conditions. Furthermore, the particle size (microversusnano), matrix voids and absorption values of the cement-TiO2composite were identified as the key factors affecting the photocatalytic performance.
Pollution with petroleum wastes is a serious environmental problem that must be treated considerably. Artificially polluted soil with oily contaminants mixtures was treated biologically using aerated bioreactor. The used oily mixtures used in this study are petroleum sludge, lubricating oil and crude oil. Crude oil and petroleum sludge were obtained from oil refinery of Al-Romayla at Al-Basrah governorate, tests were examined at the Ministry of Science and Technology. These wastes were mixed separately with soil in a ratio 7(pollutant):100 (soil) and treated by using the bioreactor. The degradation ability of microorganisms existed in the soil had been examined in low weather temperature with the aid of enzymatic reagent. The efficiency of removing the organic hydrocarbons after five weeks of treatment was 68.2 %, 74.4 % and 77.7 % for the petroleum sludge, lubricating and crude oil, respectively. The obtained results show the ability of the enzymatic reagent in the activation of micoorganisms to degrade heavy hydrocarbons substances even in cold weather.
Using new technologies and sustainable methods to obtain safe and clean water is considered one of the most important aims. In this work, almond shells have been used to prepare an activated carbon (AC) filter. Two types of sand filter media were used to simulate slow and rapid sand filters. Samples of raw water from Tigris River were taken, and the following parameters were studied (pH, turbidity, electrical conductivity (EC), total dissolved solids (TDS), sulphate and heavy metals (Iron(Fe), copper(Cu) and zinc(Zn)). Results showed that replacing sand with AC was better in the removal of Fe and Zn, when a slow sand filter was used the removal was 99% for both of them, while the enhancement in the removal seems to be small when the rapid sand filter was used.
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