Showing papers in "Water Research in 2007"

TL;DR: Although EPS is essential to sludge floc formation, excessive EPS in the form of LB-EPS could weaken cell attachment and the floc structure, resulting in poor bioflocculation, greater cell erosion and retarded sludge-water separation.

TL;DR: Conventional drinking water treatment methods were relatively inefficient for contaminant removal, while efficient removal was achieved by granular activated carbon (GAC).In wastewater treatment processes, membrane bioreactors showed limited target compound removal, but were effective at eliminating hormones and some pharmaceuticals.

TL;DR: There is a focus on polymers for primary coagulation, their use as coagulant aids, in the recycling of filter backwash waters, and in sludge thickening.

TL;DR: This review paper critically assesses the recent advances that have been achieved in this field, particularly relating to the areas of EBPR microbiology, biochemistry, process operation and process modelling.

TL;DR: A consistent and descriptive nomenclature is suggested for reactors in which the anammox process is employed, and Reactors with a high specific surface area like the granular sludge reactor employed in Rotterdam provide the highest volumetric loading rates.

TL;DR: Certain traditional parameters, including nitrate concentration, conductivity and turbidity of the effluent were assessed as predictors of total antibiotic concentration, however only conductivity demonstrated any correlation with total antibiotics concentration.

TL;DR: The methodology of studying biosorption is based on an interdisciplinary approach, whereby the phenomenon can be studied, examined and analyzed from different angles and perspectives-by chemists, (micro-)biologists as well as (process) engineers.

TL;DR: Results showed that preozonation decreased the formation of trihalomethanes, haloacetic acids (HAAs) and total organic halogen (TOX) for most waters during postchlorination, while a net increase in THMs, HAAs and TOX was observed for a water of low humic content.

TL;DR: Under alkaline conditions, the VFAs production was significantly higher than under other conditions, and the release of soluble phosphorus and ammonia and the production of methane was studied during WAS fermentation at different pHs.

TL;DR: It can be concluded that the observed elimination of fluoroquinolones in the STPs was due to their sorption to the sludge, but not biodegradation, and the occurrence and elimination of eight selected antibiotics mainly for human use were investigated at four sewage treatment plants in the Pearl River Delta.

TL;DR: A critical review of source tracking with emphasis on the extent to which methods have been tested, when methods are applicable, their shortcomings, and their usefulness in predicting public health risk or pathogen occurrence is presented.

TL;DR: Among all the steps in the plant, ozonation contributed substantially to overall removal of naproxen, ketoprofen, triclosan, crotamiton, sulfapyridine, macrolide antibiotics, and estrone.

TL;DR: Forward osmosis (FO) is a membrane treatment process that was investigated at bench scale to determine its feasibility to concentrate centrate under both batch and continuous operating conditions, and results demonstrated that high water flux and high nutrient rejection could be achieved.

TL;DR: The results indicated that phosphate was the greatest competitor with arsenic for adsorptive sites on the adsorbent and was effective for both As(V) and As(III) removal, particularly the As( III).

TL;DR: The work shows that especially carbamazepine and the beta-blockers may reach the recipient waters and there is a need to enhance their elimination in the sewage treatment plants.

TL;DR: Investigation of the effects of UV disinfection on wastewater effluent showed no reduction in the number of detectable tet(R) gene types, and Concentrations of tet(Q) were found to be highest in wastewater influent while tet(G) concentrations were highest in activated sludge.

TL;DR: For water treatment plants, no significant changes in chlorine concentration would be expected under typical pH levels and UV doses; however, the formation of (*)OH could have implications for chlorinated byproducts or decay of unwanted chemical contaminants.

TL;DR: The functional community structures (diversity and relative abundance) of major trophic groups were quantitatively analyzed by MAR-FISH and the hitherto unknown metabolic functions of Spirochaeta and candidate phylum of TM7 as well as Synergistes were found to be glucose and acetate utilization.

TL;DR: The design and validation of new TaqMan((R)) assays for microbial source tracking based on the amplification of fecal 16S rRNA marker sequences from uncultured cells of the order Bacteroidales were reported, showing the new methodologies to be more specific and sensitive.

TL;DR: Urine has a much higher phosphate concentration than sludge reject water, allowing simpler (and less expensive) process for precipitation of phosphates, and a stirred tank reactor with a special compartment for liquid solid separation was used to precipitate struvite from urine.

TL;DR: It is demonstrated that nitrifying bacteria carrying out the same metabolism coexist in all WRPs studied, evidence of functional redundancy, a feature that may help maintain the stability of the system for nitrification.

TL;DR: A computational model based on redox mediators with several populations of suspended and attached biofilm microorganisms, and multiple dissolved chemical species is described and evaluated, revealing the heterogeneous current distribution over the planar anode surface for younger and patchy biofilms, but becoming uniform in older and more homogeneousBiofilms.

TL;DR: Lab studies show that HAIX selectively removes phosphate from the background of much higher concentrations of competing sulfate, chloride and bicarbonate anions due to the combined presence of Coulombic and Lewis acid-base interactions.

TL;DR: The performance of carbon slurry was compared with many other reported adsorbent for fluoride removal and it was observed that proposed adsorption is effective in terms of performance and cost especially.

TL;DR: This study shows the importance of mutual influences between various foulants for improved understanding of fouling phenomena and shows that substances with a minor individual influence might have a large impact in mixed systems such as natural water.

TL;DR: To load as much iron within the carbon pores as possible while also rendering as much of the iron to be available for sorbing arsenic, Boehm titrations showed that surface oxidation greatly increased the concentration of carboxylic and phenolic surface groups.

TL;DR: Hydrogen production through biocatalyzed electrolysis was studied for the first time in a single chamber configuration and it was revealed that a large part of potential losses in the system were associated with a pH gradient across the membrane.

TL;DR: In this article, the anammox reaction was observed within 50 days and a total nitrogen removal rate of 26.0 kg-Nm(-3)day(-1) was obtained after 247 days.

TL;DR: Considering the difficulty of obtaining reliable PPCPs concentrations, especially those corresponding to the fractions sorbed onto sludge, a methodology to validate the experimental data has been developed and successfully applied and no influence of SRT and temperature on PPCP removal was observed.

TL;DR: Results demonstrate that UVA-TiO(2) photocatalysis can be a very effective approach for degrading sulfonamide micropollutants, particularly in natural waters exhibiting either alkaline pH or low concentrations of NOM, or both conditions.