Özdemir, Kadir

Article | 2016 | Fresenius Environmental Bulletin25 ( 12 ) , pp.6202 - 6214

In recent years, carbon nanomaterials have been used widely in water treatment technology. This study investigates to the removal of THMs from chlorinated drinking water sources by combined coagulation process using single-walled carbon nanotubes (SWCNTs) and multi-walled carbon nanotubes (MWCNTs). Terkos Lake water (TLW), Buyukçekmece Lake water (BLW) and Ulutan Lake water (ULW) were used as drinking water source in this study. Conventional coagulation using aluminum sulfate (alum) and ferric chloride (FeCl3) was also conducted using TLW, BLW and ULW samples. Also, the chlorination of raw water samples within a reaction time of 168 . . . hours was conducted in accordance with Standard Methods 5710 B. The maximum removal percentages of TTHMs (92%) was observed with combined SWCNTs and FeCl3 in chlorinated TLW, followed by BLW (82%) and ULW (78%). In BLW and ULW, TTHMs removal (86% and 83%) was highest when using FeCl3 +MWCNTs. The TTHMs removal was lowest in ULW (39% for Alum and 45% for FeCl3). On the other hand, the removal of TTHMs increases in the acidic pH levels whereas decreases alkaline pH levels. In the meantime increases the ionic strength result in decreasing the TTHMs removal for chlorinated three water sources. The results reveal that combined coagulation using carbon nanomaterials is effective for the removal of THMs from various types of chlorinated water source waters. © 2016 by PSP Daha fazlası Daha az

Altın, Süreyya | Altın, Ahmet | Kahraman, Bekir Fatih | Alemdar, Sonay | Alaydın, Elif

Article | 2015 | Fresenius Environmental Bulletin24 ( 1B ) , pp.302 - 310

In this study, the utilization of dried activated sludge for removal of Cd2+ from aqueous solution in a batch system was investigated. Initial pH, biosorbent dosage, contact time, and initial metal concentration parameters were selected to determine optimal process conditions. The bi-osorption mechanism was examined by SEM, FTIR and EDX results. The optimum conditions for Cd2+ biosorption were found to be 6.0, 120 min., 1.2 g. L-1 and 80 mg. L-1, respectively for initial pH, contact time, biosorbent dosage and initial Cd2+ concentration. Langmuir and Freundlich isotherms were used to model the biosorption equilibrium data, and it wa . . .s determined that the system followed the Langmuir isotherm, and the sorption capacity of the biosorbent was found to be 15.43 mg.g-1. Biosorption followed a pseudo-second-order rate model. Two main mechanisms of Cd2+ biosorption onto the dried activated sludge were adsorption to the C-H bonds and ion exchange with Na+, K+ and Ca2+ ions Daha fazlası Daha az