The use of a ceramic membrane is not only a new and modern technique, but reduce the use of chemicals and coagulants as well, and also having high mechanical and chemical resistance reduces costs over consecutive years. The aim of this research was to remove turbidity and biological agents such as Diatoms, Chlorophyte, Cyanophyceae, Protozoa, and Nematodes by using of ceramic membranes. A ceramic pilot plant was designed and constructed. Titanium oxide (TiO2) and aluminum oxide (Al2O3) ultrafiltration membrane with the length, diameter and pore sizes of 25 cm, 2.7 cm, and 50 nm was used. The inlet flow was the effluent resulted from the backwashing of a sand filter. This data showed that the possibility of removing of this agent was high by comparing the size of the agents and ceramic membrane pore size. Therefore, the construction of a pilot plant of ceramic membranes with 50 nm pore size and dimension (H = 1.5 m, Y = 20 cm, X = 50 cm) was offered a constant flow filtration, and sampling was performed at different times. The results showed that all biological agents except diatoms have a removal efficiency of 100% and the effluent׳s turbidity was 0.1 NTU.
The synthesis and complexive abilities of 5-mono-[(tert-butoxycarbonyl)-amino]- 11,17,23-triamino-25,26,27,28-tetrabutoxycalix[4]arene (L1) and 5,11,17,23-tetrakis[(tert-butoxycarbonyl)-amino]-25,26,27,28-tetrabutoxycalix[4]arene (L2) towards the alkali cations Li + , Na + , K + , Rb + , Cs + and the alkali earth cations Mg + 2 , Ca + 2 , Sr + 2 and Ba + 2 in methanol-chloroform mixture have been evaluated at 25 ° C using UV-Vis spectrophotometric techniques. The results show that the ligands are capable of complexing with all the cations by 1:1 metal to ligand ratios. Molecular mechanics calculations have been used to model the geometries of the alkali and alkali earth cations with the ligands using the Hyperchem 7 computational package. The selectivity is presented considering that the calculated formation constants are in the order Li + >>Na + >K + >Rb + >Cs + and Mg + 2 >Ca + 2 >Sr + 2 >Ba + 2 with the ligands. Also, L1 shows more attraction towards the smaller alkali and alkali earth metal ions than L2.
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