RESUMO
Monitoring the disinfection process and swimming pool water quality is essential for the prevention of microbial infections and associated diseases. However, carcinogenic and chronic-toxic disinfection by-products (DBPs) are formed with reactions between disinfectants and organic/inorganic matters. DBP precursors in swimming pools originate from anthropogenic sources (body secretions, personal care products, pharmaceuticals, etc.) or chemicals used in pools. Temporal (48 weeks) water quality trends of trihalomethanes (THMs), haloacetic acids (HAAs), haloacetonitriles (HANs), and halonitromethanes (HNMs) in two swimming pools (SP-A and SP-B) and precursor-DBP relationships were investigated in this study. Weekly samples were taken from swimming pools, and several physical/chemical water quality parameters, absorbable organic halides (AOX), and DBPs were determined. THMs and HAAs were the most detected DBP groups in pool water. While chloroform was determined to be the dominant THM compound, dichloroacetic acid and trichloroacetic acid were the dominant HAA compounds. The average AOX concentrations were measured to be 304 and 746 µg/L as Cl- in SP-A and SP-B, respectively. Although the amount of AOX from unknown chlorinated by-products in SP-A did not vary temporally, a significant increase in unknown DBP concentrations in SP-B was observed over time. AOX concentrations of chlorinated pool waters were determined to be an important parameter that can be used to estimate DBP concentrations.
RESUMO
In this study, copper recovery and sensor integration for concentrate flows of membrane processes were studied. In the first phase, cementation tests for copper recovery were carried out with various different Fe/Cu stoichiometric ratios, copper concentrations, temperatures, and stirring speeds. The effects of the parameters which were stirring speed, temperature, stoichiometric ratio, and concentration in the solution on the cementation process were determined. In the second phase, a novel electroanalytical sensor was applied to concentrate flow. The application of cementation within the scope of precious metal recovery from concentrate streams by integrating a sensor to the process as an innovative online-sensing-approach is conducted. Four different copper concentrations (64, 128, 512, 1280 mg/L) and 5 different Fe/Cu stoichiometric ratios for these concentrations were studied. For concentrations of 64 mg/L and 128 mg/L, 1/1, 2/1, 5/1, 7/1, 10/1 Fe/Cu ratios and for both 512 mg/L and 1280 mg/L concentrations, 1/1, 1.25/1, 1.5/1, 1.75/1, 2/1 Fe/Cu ratios were applied. The cumulative average of ICP-MS linearity of developed electroanalytical sensor was 94.9%. The efficient recovery of copper from the concentrate flows with the sensor integrated-cementation process has a strong potential for "Industry 4.0" applications with enhanced automation levels.
