Effects of a sidestream concentrated oxygen supply system on the membrane filtration performance of a high-loaded membrane bioreactor.

To investigate the influence of high-pressure and shear effects introduced by a concentrated oxygen supply system on the membrane filtration performance, a laboratory-scale membrane bioreactor (MBR) fed artificial municipal wastewater was operated continuously for 80 days in four phases equipped with different aerations systems: (P1) bubble diffusers (days 0-40), (P2) concentrated oxygen supply system, the supersaturated dissolved oxygen (SDOX) (days 41-56), (P3) bubble diffusers (days 57-74), and (P4) SDOX (days 75-80). Various sludge physical-chemical parameters, visual inspection of the membrane, and permeability evaluations were performed. Results showed that the high-pressure effects contributed to fouling of the membranes compared to the bubble diffuser aeration system.

Bromide occurrence in Croatian groundwater and application of literature models for bromate formation.

Bromide in water can form undesirable by-products such as bromate when treated by ozonation during drinking water production. The maximum contaminant level (MCL) for bromate is 10 µg/L in most countries because it is suspected of being carcinogenic. In this paper, the geographical distribution of bromide concentration in Croatian groundwater is presented covering the Pannonian basin and the Dinarides (Adriatic Sea).

Use of near-infrared spectroscopy on predicting wastewater constituents to facilitate the operation of a membrane bioreactor.

The use of near-infrared (NIR) spectroscopy in wastewater treatment has continuously expanded. As an alternative to conventional analytical methods for monitoring constituents in wastewater treatment processes, the use of NIR spectroscopy is considered to be cost-effective and less time-consuming. NIR spectroscopy does not distort the measured sample in any way as no prior treatment is required, making it a waste-free technique.

Supersaturated-oxygen aeration effects on a high-loaded membrane bioreactor (HL-MBR): Biological performance and microbial population dynamics.

Conventional diffused aeration systems (such as fine-bubble diffusers) exhibit a poor oxygen transfer in wastewater treatment plants (WWTPs), particularly when operating at sludge concentrations higher than 15 g L. The supersaturated dissolved oxygen (SDOX) system has been proposed as an alternative for supplying dissolved oxygen (DO) at high mixed liquor suspended solids (MLSS) concentrations. The advantages introduced by such technology include the possibility of operating WWTPs at much higher than usual MLSS concentrations, increasing the treatment capacity of WWTPs.

Limitations imposed by conventional fine bubble diffusers on the design of a high-loaded membrane bioreactor (HL-MBR).

The operation of membrane bioreactors (MBRs) at higher than usual mixed liquor suspended solids (MLSS) concentrations may enhance the loading rate treatment capacity while minimizing even further the system's footprint. This requires operating the MBR at the highest possible MLSS concentration and biomass activity (e.g.

Adsorption Characteristics of Different Adsorbents and Iron(III) Salt for Removing As(V) from Water.

The aim of this study is to determine the adsorption performance of three types of adsorbents for removal of As(V) from water: Bayoxide E33 (granular iron(III) oxide), Titansorb (granular titanium oxide) and a suspension of precipitated iron(III) hydroxide. Results of As(V) adsorption stoichiometry of two commercial adsorbents and precipitated iron(III) hydroxide in tap and demineralized water were fitted to Freundlich and Langmuir adsorption isotherm equations, from which adsorption constants and adsorption capacity were calculated. The separation factor for the three adsorbents ranged from 0.

Removal of antimicrobials using advanced wastewater treatment.

Removal of numerous classes of pharmaceuticals from the municipal and industrial wastewater, using conventional wastewater treatment, is incomplete and several studies suggested that improvement of this situation would require the application of advanced treatment techniques. This is particularly important for the treatment of industrial effluents, released from pharmaceutical industries, which can contain rather high concentrations of antimicrobials. The aim of this work was to evaluate membrane bioreactors (MBRs), nanofiltration, reverse osmosis and ozonation, as well as their combinations, for the removal of antimicrobials from a synthetic wastewater which simulated highly contaminated industrial effluents.

Identification of biotransformation products of macrolide and fluoroquinolone antimicrobials in membrane bioreactor treatment by ultrahigh-performance liquid chromatography/quadrupole time-of-flight mass spectrometry.

Ultrahigh-performance liquid chromatography coupled to quadrupole time-of-flight mass spectrometry was applied for the identification of transformation products (TPs) of fluoroquinolone (norfloxacin and ciprofloxacin) and macrolide (azithromycin, erythromycin, and roxitromycin) antimicrobials in wastewater effluents from a Zenon hollow-fiber membrane bioreactor (MBR). The detected TPs were thoroughly characterized using the accurate mass feature for the determination of the tentative molecular formulae and MS-MS experiments for the structural elucidation of unknowns. Several novel TPs, which have not been previously reported in the literature, were identified.