A novel approach to calcium removal from calcium-rich industrial wastewater

Calcium-rich wastewater is a problem for industries due to calcification during downstream processing. The potential for Ca2+ removal from industrial wastewater through ureolytic microbiological carbonate precipitation was investigated for the first time. Batch experiments were used to determine feasible urea concentrations and hydraulic retention times. These results were applied in a semi-continuous reactor system, where the emphasis was placed on the development of a calcifying sludge. Calcium removal in excess of 90% was achieved throughout the experimental period, while the effluent pH remained at a reasonable level.     

Degradation of acetaminophen by Delftia tsuruhatensis and Pseudomonas aeruginosa in a membrane bioreactor

The incidence and fate of pharmaceuticals in the water cycle impose a growing concern for the future reuse of treated water. Because of the recurrent global use of drugs such as Acetaminophen (APAP), an analgesic and antipyretic drug, they are often detected in wastewater treatment plant (WWTP) effluents, receiving surface waters and drinking water resources. In this study, the removal of APAP has been demonstrated in a membrane bioreactor (MBR) fed with APAP as the sole carbon source. After 16 days of operation, at a hydraulic retention time (HRT) of 5 days, more than 99.9% removal was obtained when supplying a synthetic WWTP effluent with 100 μg APAP L⁻¹. Batch experiments indicated no sorption of APAP to the biomass, no influence of the WWTP effluent matrix, and the capability of the microbial consortium to remove APAP at environmentally relevant concentrations (8.3 μg APAP L⁻¹). Incubation with allylthiourea, an ammonia monooxygenase inhibitor, demonstrated that the APAP removal was mainly associated with heterotrophic bacteria and not with the ammonia-oxidizing bacteria. Two APAP degrading strains were isolated from the MBR biomass and identified as Delftia tsuruhatensis and Pseudomonas aeruginosa. During incubation of the isolates, hydroquinone - a potentially toxic transformation product - was temporarily formed but further degraded and/or metabolized. These results suggest that the specific enrichment of a microbial consortium in an MBR operated at a high sludge age might be a promising strategy for post-treatment of WWTP effluents containing pharmaceuticals.     

Virus disinfection in water by biogenic silver immobilized in polyvinylidene fluoride membranes

The development of innovative water disinfection strategies is of utmost importance to prevent outbreaks of waterborne diseases related to poor treatment of (drinking) water. Recently, the association of silver nanoparticles with the bacterial cell surface of Lactobacillus fermentum (referred to as biogenic silver or bio-Ag⁰) has been reported to exhibit antiviral properties. The microscale bacterial carrier matrix serves as a scaffold for Ag⁰ particles, preventing aggregation during encapsulation. In this study, bio-Ag⁰ was immobilized in different microporous PVDF membranes using two different pre-treatments of bio-Ag⁰ and the immersion-precipitation method. Inactivation of UZ1 bacteriophages using these membranes was successfully demonstrated and was most probably related to the slow release of Ag⁺ from the membranes. At least a 3.4 log decrease of viruses was achieved by application of a membrane containing 2500 mg bio-Ag⁰_powder m⁻² in a submerged plate membrane reactor operated at a flux of 3.1 L m⁻² h⁻¹. Upon startup, the silver concentration in the effluent initially increased to 271 μg L⁻¹ but after filtration of 31 L m⁻², the concentration approached the drinking water limit ( = 100 μg L⁻¹). A virus decline of more than 3 log was achieved at a membrane flux of 75 L m⁻² h⁻¹, showing the potential of this membrane technology for water disinfection on small scale.     

Optimierung von schweiβbaren mikrolegierten Stählen zum Schmieden

Herstellung von 18 mikrolegierten Versuchsschmelzen, die anschlieβend nach zwei verschiedenen Zeittemperaturprogrammen beim Schmieden thermomechanisch behandelt werden. Zusätzliches Normalglühen eines Teils der Proben. Untersuchung des Einflusses der chemischen Zusammensetzung, der Schmiedeparameter und der Probendicke von 44 mm auf die mechanischen Eigenschaften sowie die Kerbschlagwerte der Proben. Feststellung, daβ die thermomechanische Behandlung ausgezeichnete mechanische Eigenschaften auch bei gröβeren Enddicken liefert, während das Normalglühen die Festigkeitssteigerung der thermomechanischen Behandlung praktisch auslöscht.     

Electrolytic removal of 17α‐ethinylestradiol (EE2) in water streams

The electrolytic removal of ethinylestradiol (EE2), the most potent synthetic estrogen, in effluent of a membrane bioreactor (MBR) treating hospital sewage and in drinking water, was studied at dosed concentrations of about 1 mg EE2 L^?1. Removal efficiencies of up to 98% were obtained with supplemental efficient eradications of bacteria (up to 3.4 log units). Residual effects were observed when a treated flow was mixed with an untreated flow. An increasing concentration of NaCl resulted in an enhanced EE2 removal. This effect was more pronounced in MBR effluent than in drinking water. To approach more environmentally realistic concentrations, an experiment with initial concentration of 10 µg EE2 L^?1 drinking water was set up, still resulting in an EE2 removal of 85%. Copyright © 2006 Society of Chemical Industry     

Evaluation of quarternary aggregate resources in Norway

The paper refers to some results of recent research in Norway on aggregate/concrete interaction. The objective has been to establish criteria for classification, based on knowledge of the geological origin of the aggregates. The evaluation system developed incorporates an automatic data processing information system and a new method of mineralogical quality classification of sand aggregates. The latter refers primarily to the properties of aggregates determining the water requirement and strength of concrete. The system has been used for evaluating a large number of Quaternary aggregate deposits throughout the country, and the results have been correlated with relevant concrete testing.     

Beitrag zur Kenntnis des Reaktionsablaufes zwischen Roheisen und Schlacke im Hochofen

Zusammenhänge zwischen der Roheisentemperatur, dem Basengrad der Schlacke und der Zusammensetzung von Roheisen und Schlacke. Reduktionsvorgänge im Gestell des Hochofens. Überwachung des Hochofenbetriebsablaufes und der Roheisenzusammensetzung an Hand der Roheisentemperatur. Auswirkungen von Änderungen der Windtemperatur und des Kokssatzes auf die Gestellreaktionen.     

Broadband emission from a multicore fiber fabricated with granulated oxides

We demonstrate a multicore multidopant fiber which, when pumped with a single pump source around approximately 800 nm, emits a more than one octave-spanning fluorescence spectrum ranging from 925 to 2300 nm. The fiber preform is manufactured from granulated oxides and the individual cores are doped with five different rare earths, i.e., Nd3+, Yb3+, Er3+, Ho3+, and Tm3+.     

Chemical and biological technologies for hydrogen sulfide emission control in sewer systems: a review

Biogenic corrosion of sewers represents a cost of about 10% of total sewage treatment cost in Flanders (Belgium) and is further increasing. In the past, research has resulted in a number of prevention methods, such as injection of air, oxygen, H(2)O(2), NaClO, FeCl(3) and FeSO(4). The possibility of biological oxidation of sulfide using nitrate as the electron acceptor has also been explored in sewer systems. However, all of these methods have a problem with the high cost (euro 1.9-7.2 kg(-1)S removal). In this review, new approaches for hydrogen sulfide emission control in sewer systems are discussed. The control of hydrogen sulfide emission by using a microbial fuel cell (MFC) can be cost-effective while the BOD is removed partially. The use of phages that target sulfate-reducing bacteria (SRB) can possibly inhibit sulfide formation. Novel inhibitors, such as slow release solid-phase oxygen (MgO(2)/CaO(2)) and formaldehyde, warrant further study to control hydrogen sulfide emission in sewer systems.