Davor Dolar

Effect of water matrices on removal of veterinary pharmaceuticals by nanofiltration and reverse osmosis membranes

This study explored the removal of five veterinary pharmaceuticals (VPs) (sulfamethoxazole (SMETOX), trimethoprim (TMP), ciprofloxacin (CIPRO), dexamethasone (DEXA) and febantel (FEBA)) from different water matrices (Milli-Q water, model water, tap water and real pharmaceutical wastewater using four types of nanofiltration (NF) membranes (NF90, NF270, NF and HL) and two reverse osmosis (RO) membranes (LFC-1 and XLE). All VPs were added to different water matrices at a concentration of 10 mg/L. Rejections of VPs and water flux were measured. The rejection increased with increase of molecular weight. The highest rejections were obtained with RO membranes (LFC-1, XLE) and tight NF (NF90) membrane. In general, the rejection of VPs was higher in model water and tap water than in Milli-Q water, but the water flux was lower. This was mainly explained by ion adsorption inside the membranes pores. Narrower pore size counteracted the effect of presence of low concentration of natural organic matter (NOM) in tap water. The NOM was assumed to enhance the adsorption of VPs onto membrane surface, increased the size exclusion and electrostatic repulsion also appeared during the transport. Investigated water matrices had influence on water flux decline due to their complexity.

Development and optimization of the SPE procedure for determination of pharmaceuticals in water samples by HPLC-diode array detection.

This paper focuses on the investigation of different types of SPE sorbents for the preconcentration of eight veterinary pharmaceuticals from water samples. The pharmaceuticals studied were sulfamethazine, sulfadiazine, sulfaguanidine, trimethoprim, oxytetracycline, enrofloxacin, norfloxacin and penicillin G/procaine. Five different SPE materials (Strata-X, Strata-X-C, Strata SDB-L, Strata C8 and Strata C18) from Phenomenex were compared with Oasis HLB with a view to obtaining the best cartridges for all pharmaceuticals investigated. Extraction efficiency was determined by HPLC with diode array detection (DAD). HPLC-DAD separation and quantification of the selected pharmaceuticals were carried out under gradient elution by a binary mixture of 0.01 M oxalic acid and ACN based on cyano modified column (LiChrosphere 100 CN) from Merck. Strata-X provided the best results in the preconcentration of 100 mL water samples, yielding average pharmaceutical recoveries of higher than 90%, except for sulfaguanidine (76.1%). The developed Strata-X-HLPC-DAD method was validated and applied, for the efficient investigation of reverse osmosis/nanofiltration membranes and for the removal of these eight pharmaceuticals from the production wastewater samples. NF90 and XLE membranes were shown to be the best for the rejection of all investigated pharmaceuticals.

RO/NF membrane treatment of veterinary pharmaceutical wastewater: comparison of results obtained on a laboratory and a pilot scale

BackgroundEmerging contaminants (ECs) are commonly derived from industrial wastewater, which is often a consequence of an inadequate treatment of the latter. Improperly pretreated pharmaceutical wastewater could cause difficulties in operations of wastewater treatment plants while incomplete elimination of ECs during the processing might result in their appearance in drinking water.MethodsThis paper deals with membrane treatment of pharmaceutical wastewater on a laboratory and a pilot scale as well as with the removal of the following veterinary pharmaceuticals (VPs) (sulfamethoxazole, trimethoprim, ciprofloxacin, dexamethasone, and febantel).ResultsThe pretreatment of pharmaceutical wastewater by means of coagulation and microfiltration (MF) prevented the irreversible fouling of the fine porous structure of the reverse osmosis (RO) and nanofiltration (NF) membranes which were used in the final stage of wastewater processing. The percentage of the removal of the selected VPs ranges from 94% to almost 100% in the case of NF and RO membranes in both scales. The recovery percentage concerning the pilot scale amounted to 88%. Membrane cleaning was successfully carried out in both scales.ConclusionsThe differences in retention between laboratory and pilot tests are due to different raw wastewater quality and different recovery and hydrodynamic of the two systems. Fouling and concentration polarization were more pronounced in laboratory setup (frame-plate module) than in pilot unit (spiral module). The proposed integrated membrane treatment (coagulation, MF, NF, and RO) can be employed for treatment of wastewater originating from pharmaceutical factory. The obtained permeate can be safely discharged to sewer system or could be reused in manufacturing process.

SPE-HPLC/DAD determination of trimethoprim, oxytetracycline and enrofloxacin in water samples

In this paper high-performance liquid chromatography with diode array UV detection (HPLC/DAD) after SPE sample pretreatment for simultaneous analysis of pharmaceuticals from three different classes: enrofloxacin, oxytetracycline and trimethoprim, has been developed, optimised and validated. The chromatographic separation was developed on spiked wellspring water samples and checked on model wastewater samples of veterinary pharmaceuticals before and after RO/NF membrane treatment (feed and permeate streams) and on process wastewaters of industrial origin. Chromatographic separation was performed on Varian ProStar HPLC/DAD with C-18 column (Microsorb-MV 100 C18, 150 × 4.6 mm; 5 µm, Varian, USA). Detection and quantification was performed at 254 nm. The best separation was achieved with mobile phase 0.5% formic acid and 1% trifluoroacetic acid in 0.05 M ammonium acetate-methanol, 70 + 30, (v/v) after extraction procedure on polystyrenedivinylbenzene Varian Empore extraction disks. The extraction efficiency was checked by recovery experiments.

Treatment of landfill leachate by membrane processes of nanofiltration and reverse osmosis

AbstractLandfill leachate from Jakusevec, Zagreb, Croatia was treated by membrane processes of nanofiltration (NF) and reverse osmosis (RO). Different types of membranes were selected to obtain the parameters of leachate contaminants below maximum concentration levels (MCLs), defined by the Croatian law and EU directive. As a pretreatment of landfill leachate, coagulation and filtration were used. Parameters of total carbon, total organic carbon (TOC), inorganic carbon, chemical oxygen demand (COD), pH, turbidity, conductivity, concentration of different inorganic ions, heavy metals, etc., were analyzed in all steps. The landfill leachate was relatively low loaded with organic substances and ammonia; COD, TOC, and NH4+-N of real sample were 1,720.0 mgO L−1, 1,260.5 mgC L−1, and 1,147.6 mg L−1, respectively. Their concentrations decreased after coagulation for 27.9, 58.6, and 7.9%, respectively. RO/NF membranes (NF270, NF90, and XLE) additionally decreased COD and TOC for >94.6% and >92.5%, respectively. A...

NF/RO removal of enrofloxacin and its photodegradation products from water

Abstract Once released into the environment pharmaceuticals undergo a series of processes leading to their degradation. Photolysis induced by sunlight is the most important way of pharmaceuticals degradation in water. In this work the removal of enrofloxacin (ENRO) and its photodegradation products with nanofiltration (NF) and reverse osmosis (RO) membranes was investigated. ENRO solution (10 mg L−1, pH = 8) was irradiated under artificial light for 2 h. As a result the degradation of ENRO produced three photoproducts with molecular weights (MW) 389, 373 and 114 g mol−1. Reverse osmosis (LFC–1, SWC4+) and tight nanofiltration (NF90) membranes almost removed (>99.99%) all the compounds (parent and photodegradation products), but the other nanofiltration (DK, NF and HL) membranes removed more than 92%, with one exception (36.96% for the compound with MW 114 g mol−1) obtained using HL membrane.

Efficiency of RO/NF membranes at the removal of veterinary antibiotics

The production of pharmaceuticals has increased rapidly during the last several decades as they have been used for the health of both humans and animals. Routes of environmental exposure include the release of treated wastewater, the land disposal of livestock manures and municipal biosolids (i.e. sewage sludge), as well as the use of medicated aquaculture feed. This study deals with application of reverse osmosis (RO) and nanofiltration (NF) membranes for removing of antibiotic residues (sulfamethoxazole, trimethoprim, ciprofloxacin, dexamethasone and febantel) and their mixture. According to the results obtained in this work the use of RO (LFC-1 and XLE) and the tight NF (NF90) membranes are recommended to achieve a high level of retention (>95%) of all selected veterinary antibiotics (VAs). Nanofiltration NF270, NF and HL membranes showed a lower rejection of individual components, but much higher in a mixture solution, due to the synergistic effect.