Seasonal analysis of commonly prescribed antibiotics in Istanbul city.

Antibiotics are among the most common medicine groups since they are used to treat infectious diseases, as nutritional supplements in livestock breeding, and for preservation in the food industry. Turkey is among the highest antibiotic consumers in the world. In the present study, the most popular 14 antibiotics available in Turkey were monitored in one hospital sewage and two urban wastewater treatment plant influents and effluents seasonally in Istanbul province, the largest metropolitan center in Turkey. The present research aimed to develop a robust analytical method to determine 14 antibiotics, including six chemical groups, in environmental matrices which are considered significant antibiotic pollution sources, namely hospital sewage and urban wastewater. Solid-phase extraction (SPE) and UPLC-MS/MS analysis parameters included optimized column temperature, eluent, mobile phase, and flow rate. Three SPE cartridges were employed in recovery studies. The antibiotic recovery rates varied between 40 and 100%, and all analytes were identified within 3 min with UPLC-MS/MS under optimal conditions. It was determined that method detection limits (MDLs) varied between 0.07 and 2.72 µg/L for the antibiotics. In all seasons, the highest beta-lactam group antibiotic concentrations were identified in hospital sewage. The season with the greatest variety of antibiotics in urban wastewater was spring. Clarithromycin and ciprofloxacin were the antibiotics determined at the highest concentration in the influent and effluent of the wastewater treatment plant in all seasons. This study showed that the most widely used beta-lactam group antibiotics were found in high amounts in hospital sewage wastewater but in low concentrations in the treatment plants, and hence, it is seen that the degradability of beta-lactam group antibiotics was high. The presence of clarithromycin, ciprofloxacin, lincomycin, levofloxacin, and trimethoprim antibiotics in hospital sewage in higher amounts and also in inlet and outlet of wastewater treatment plants proves that those are resistant antibiotics.

Novel hybrid treatments of textile wastewater by membrane oxidation reactor: Performance investigations, optimizations and efficiency comparisons.

Feasible reclamation of industrial wastewaters by consuming less resource and time requires researchers to develop advanced and sophisticated solutions to meet today's versatile needs. In this respect, novel technological applications of hybrid membrane oxidation reactor (MOR) comprising of the Fenton or photo-Fenton enhanced ultrafiltration (FEUF and pFEUF), was demonstrated for treating textile washing wastewater. Their comparative hybrid performances were explored based on response surface analyses of Taguchi experimental designs that were optimized for maximized responses at minimum oxidant and acid consumptions. From eleven specific variables, those affecting the hybrid treatment performances at significant levels were found as H2O2 amount, process time, membrane type, Fe2+ concentration and temperature. The pFEUF treatment showed better and faster organics removal efficiency than by FEUF, and the UF process was seen to be more affected from changing operational conditions in pFEUF. Organic pollutants were oxidized by 56.6 ±â€¯8.7% degradation and 31.5 ±â€¯3.2% mineralization, while UF allowed a synergistic contribution to the hybrid MOR performance by 38.1 ±â€¯4.7% and 17.3 ±â€¯3.1%, respectively. Compared to simultaneous MOR and external UF after Fenton, sequential MOR was found as the best solution by an efficiency of 84.5% COD, 70.5% TOC, and 155.6 L/m2·h. The effluents could be readily produced with quality suitable for directly discharging to the sewage infrastructure system resulting in a complete treatment. This study proved that the developed MOR techniques are technologically favorable for the treatment of industrial organic wastewaters due to high treatment performances and less resource, time and land needs. It can be finally declared that they can be used as rather attractive solutions for not only wastewater reclamation but also water recovery by further handling of their effluents.

Biodiesel production from sunflower, soybean, and waste cooking oils by transesterification using lipase immobilized onto a novel microporous polymer.

This study aims at carrying out lipase-catalyzed synthesis of fatty acid methyl esters (biodiesel) from various vegetable oils using lipase immobilized onto a novel microporous polymeric matrix (MPPM) as a low-cost biocatalyst. The research is focused on three aspects of the process: (a) MPPM synthesis (monolithic, bead, and powder forms), (b) microporous polymeric biocatalyst (MPPB) preparation by immobilization of lipase onto MPPM, and (c) biodiesel production by MPPB. Experimental planning of each step of the study was separately carried out in accordance with design of experiment (DoE) based on Taguchi methodology. Microporous polymeric matrix (MPPM) containing aldehyde functional group was synthesized by polyHIPE technique using styrene, divinylbenzene, and polyglutaraldehyde. Thermomyces lanuginosus lipase was covalently attached onto MPPM with 80%, 85%, and 89% immobilization efficiencies using bead, powder, and monolithic forms, respectively. Immobilized enzymes were successfully used for the production of biodiesel using sunflower, soybean, and waste cooking oils. It was shown that immobilized enzymes retain their activities during 10 repeated batch reactions at 25 degrees C, each lasting 24h. Since the developed novel method is simple yet effective, it could have a potential to be used industrially for the production of chemicals requiring immobilized lipases.

Investigation of process performance and fouling mechanisms in micellar-enhanced ultrafiltration of nickel-contaminated waters.

Nickel removal from aqueous solution by micellar-enhanced ultrafiltration (MEUF) with relatively low transmembrane pressures was investigated at varying conditions of sodium lauryl ether sulfate (SLES) and nickel concentrations, transmembrane pressure and sodium chloride content. Process employed in continuous filtration mode, could be operated within a short time of 30 min presenting high rejection of nickel and SLES at high transient fluxes. Under the effect of increasing transmembrane pressure, the rejection of nickel and SLES increased, but the transient flux decreased. The existence of salt caused to decrease both rejections and flux. Nickel rejection, SLES rejection and flux were established as 98.6%, 75.7% and 0.304 m(3)/m(2)h, respectively, for the conditions of surfactant to metal (S/M) ratio of 10 (SLES = 2 mM), transmembrane pressure of 250 kPa without NaCl content at the end of 90-min operation time. The analyses related to the membrane fouling were carried out using adsorptive fouling models. It has been determined that, the fouling occurs as a dynamic function of various process conditions studied, and depends strongly on mechanisms controlled by the formation of gel layer and its bridging over the pore entrances simultaneously together with partial constriction of membrane pores by surfactant adsorption.