Sewage fungus: studies of Sphaerotilus slimes using laboratory recirculating channels

Laboratory recirculatory channels for the study of sewage fungus incorporate control of water velocity, flow, temperature, and nutrient content. Growth conditions for various types of sewage fungus have been investigated, in particular growth and self-purification capacity of Sphaerotilus-dominated slimes at various concentrations of glucose, acetate, and phosphate.     

Nitrous oxide emissions from the oxidation tank of a pilot activated sludge plant

This study discusses the results of the continuous monitoring of nitrous oxide emissions from the oxidation tank of a pilot conventional wastewater treatment plant. Nitrous oxide emissions from biological processes for nitrogen removal in wastewater treatment plants have drawn great attention over the last years, due to the high greenhouse effect. However, even if several studies have been carried out to quantify nitrous oxide emission rates from different types of treatment, quite wide ranges have been reported. Only grab samples or continuous measurements over limited periods were considered in previous studies, which can account for the wide variability of the obtained results. Through continuous monitoring over several months, our work tries to fill this gap of knowledge and get a deeper insight into nitrous oxide daily and weekly emission dynamics. Moreover, the influence of some operating conditions (sludge age, dissolved oxygen concentration in the oxidation tank, nitrogen load) was studied to determine good practices for wastewater treatment plant operation aiming at the reduction of nitrous oxide emissions. The dissolved oxygen set-point is shown to play a major role in nitrous oxide emissions. Low sludge ages and high nitrogen loads are responsible for higher emissions as well. An interesting pattern has been observed, with quite negligible emissions during most of the day and a peak with a bell-like shape in the morning in the hours of maximum nitrogen load in the plant, correlated to the ammonia and nitrite peaks in the tank.     

Oxidation of pharmaceuticals during ozonation of municipal wastewater effluents: a pilot study

To reduce the release of pharmaceuticals and endocrine disruptors into the aquatic environment or to remove them from wastewater intended for direct or indirect reuse, the application of advanced wastewater treatment may be required. In the present study, municipal wastewater effluents were treated with ozone (O3) in a pilot-scale plant consisting of two bubble columns. The investigated effluents, which varied in suspended solids concentrations, comprised an effluent of conventional activated sludge treatment (CAS), the same effluent dosed with 15 mg of TSS L(-1) of activated sludge (CAS + SS), and the effluent of a membrane bioreactor pilot plant (MBR). Selected classes of pharmaceuticals were spiked in the wastewater at realistic levels ranging from 0.5 to 5 microg L(-1). Samples taken at the inlet and the outlet of the pilot plant were analyzed with liquid chromatography (LC)-electrospray tandem mass spectrometry (MS). Macrolide and sulfonamide antibiotics, estrogens, and the acidic pharmaceuticals diclofenac, naproxen, and indomethacin were oxidized by more than 90-99% for O3 doses > or = 2 mg L(-1) in all effluents. X-ray contrast media and a few acidic pharmaceuticals were only partly oxidized, but no significant differences were observed among the three effluents. These results show that many pharmaceuticals present in wastewater can be efficiently oxidized with O3 and that suspended solids have only a minor influence on the oxidation efficiency of nonsorbing micropollutants.     

Removal of estrogens in municipal wastewater treatment under aerobic and anaerobic conditions: consequences for plant optimization

The removal of estrogens (estrone E1, estradiol E2, and ethinylestradiol EE2) was studied in various municipal wastewater treatment processes equipped for nutrient removal. A biological degradation model is formulated, and kinetic parameters are evaluated with batch experiments under various redox conditions. The resulting model calculations are then compared with sampling campaigns performed on differenttypes of full-scale plant: conventional activated-sludge treatment, a membrane bioreactor, and a fixed-bed reactor. The results show a > 90% removal of all estrogens in the activated sludge processes. (Due to the analytical quantification limit and low influent concentrations, however, this removal efficiency represents only an observable minimum.) The removal efficiencies of 77% and > or = 90% for E1 and E2, respectively, in the fixed-bed reactor represent a good performance in view of the short hydraulic retention time of 35 min. The first-order removal-rate constant in batch experiments observed for E2 varied from 150 to 950 d(-1) for a 1 gSS L(-1) sludge suspension. The removal efficiency of E1 and EE2 clearly depends on the redox conditions, the maximum removal rate occurring under aerobic conditions when E1 was reduced to E2. Sampling campaigns on full-scale plants indicate that the kinetic values identified in batch experiments (without substrate addition) for the natural estrogens may overestimate the actual removal rates. Although this paper does not give direct experimental evidence, it seems that the substrate present in the raw influent competitively inhibits the degradation of E1 and E2. These compounds are therefore removed mainly in activated sludge compartments with low substrate loading. Theoretical evaluation leads us to expect that diffusive mass transfer inside the floc (but not across the laminar boundary layer) appreciably influences the observed degradation rates of E1 and E2, but not of EE2.     

Treatment of toilet wastewater for reuse in a membrane bioreactor.

Toilet wastewater is treated and reused on site at Europe's highest membrane bioreactor (MBR), located in a cable car mountain station in the ski resort of Zermatt. Negative impacts on the sensitive mountain environment are minimised by reusing close to 100% of the treated wastewater for toilet flushing. Besides 100% nitrogen removal, 80% of phosphorus was also eliminated. This paper presents operational results, optimisations of sludge management, decoloration and long-term maintenance of biomass in the very low-loaded summer season. From a global view the experiences and results of the project are of great importance, proposing a solution to a problem existing 100-fold in the Alps as well as in arid regions all over the world: reducing water consumption for sanitation by reuse.     

Current aspects and problems relating to medical ethics in oncology

A case history of a breast cancer patient is used to exemplify ethical dilemmas in medical oncology: information of a cancer patient and his family, ethical problems with genetic testing, ethical issues with do-not-resuscitate-orders, ethical dilemmas with limited resources, problems with insurance companies, ethical issues in clinical trials and questions in dying patients including physician-assisted suicide and active euthanasia. Medical oncologists have to develop skills in recognizing ethical dilemmas in patient care and must prepare to cope with the many and complex ethical issues in the care of oncology patients.     

The 42+ T Hybrid Magnet Project at CNRS-LNCMI-Grenoble

Hybrid magnets, the combination of a resistive inner coil with a superconducting outer one, allow to generate the highest continuous magnetic fields for a given electrical power installation. A new superconducting coil outsert has been designed to be integrated in the existing infrastructure at LNCMI-Grenoble (GHMFL). Based on the specific development of a Nb–Ti Rutherford Cable On Conduit Conductor (RCOCC) cooled at 1.8 K by a bath of superfluid helium at atmospheric pressure, the superconducting coil aims to produce a continuous magnetic field of 8.5 T in a 1.1 m bore diameter. Combined with resistive insert coils, an overall continuous magnetic field of 42+ T will be produced in a 34 mm warm aperture. The main results of the conceptual study will be presented together with first developments and tests of the RCOCC.     

Elaboration of low viscosity and high impact polypropylene blends through reactive extrusion

In this work, a reactive high flow polypropylene, PP800 (η₀ = 40 Pa s, 190°C), is extruded with a commercial compound of polypropylene and ethylene‐propylene random copolymer (η₀ = 3000 Pa s, 190°C). On one hand, the fluidity of resulting blends is highly increased but, on the other hand, matrix degradation leads to a strong decrease of the impact behavior and tensile strain. Then, the addition of 10 wt% of propylene‐based copolymer (PBC) leads to a very interesting impact enhancement while keeping high fluidity. A study of morphological, thermal, and dynamical thermal mechanical properties reveal the anchoring of semi crystalline propylene segments of PBC droplets at the interface with the PP matrix. On the contrary, the addition of ethylene‐based copolymer (EBC) is not able to restore satisfactory impact properties. POLYM. ENG. SCI., 56:418–426, 2016. © 2016 Society of Plastics Engineers