The Fate of Heavy Metals in Pilot-Plant Scale Upflow Sludge-Blanket Clarifiers

T he R emoval of heavy metals and aluminium residuals during upflow sludge-blanket clarification was investigated using a pilot-plant system. Pilot units treating predosed raw water on site were assessed for sludge-blanket formation and stabilization, and were found to produce clarified water of a comparable quality to the main works units after the start-up and stabilization periods were complete. The heavy metals Cr, Fe, Mn, and Ni were the only heavy metals detectable at the investigation site and these occurred at concentrations well below guidelines values for potable abstraction and supply.
Mean removals of Fe, Mn, Cr, and Ni were about 98, 89, 51, and 30 per cent respectively, during steady-state operation, and Fe, Mn, and Cr all displayed reduced removals during transient changes in surface load, whereas Ni removal appeared to be relatively independent. Aluminium residuals derived from the dosed alum coagulant also showed decreases in removal from about 83 per cent during steady-state operation to between 40 and 50 per cent during transient experiments.     

Development of controlled strength-loss resorbable beta-tricalcium phosphate bioceramic structures

Controlling the strength-loss rate during biodegradation is a bottleneck in developing viable resorbable ceramic implants. Resorbable beta-tricalcium phosphate (β-TCP) bioceramic is known for its excellent biocompatibility. However, it exhibits poor sinterability and poor flexural strength. Here, we improved sintering behavior and biaxial flexural strength of β-TCP bioceramic without altering its biocompatibility by introducing multi-oxide sintering additives, in small quantities. These additives could also tailor the rate of resorption and hardness deterioration of β-TCP. A range of additives were prepared and introduced into β-TCP powder. Resultant powders were uniaxially pressed and sintered at 1250 °C, in air. Considerable improvement in densification (up to 33%) and biaxial flexural strength (up to 43%) were achieved. X-ray powder diffraction (XRD) analysis confirmed that the additives didn't alter the phase purity. In vitro cytotoxicity and biocompatibility analyses were performed using a prostate cancer cell-line. Results showed that the doped and pure β-TCP structures were non-toxic and biocompatible.     

Corporate strategic objectives for establishing relationships withuniversity research centers

Organizations face increased pressures to continually advance knowledge and new technologies long-term success and prosperity. University research centers offer important interorganizational linkages for industry-university collaboration, conducive for advancing knowledge and new technologies. This study examined industry's strategic objectives for establishing relationships with university research centers. As a result of this multimethod exploratory field study, the authors have identified three clusters of industrial firms with different strategic objectives: collegial players, aggressive players, and targeted players. Collegial players are predominately large firms working with university research centers on topics of interest to the firm which are perceived to have long-term value rather than the promise of immediate commercial opportunities. Aggressive players are a mix of both large and small firms employing relationships with university research center primarily to develop and commercialize a wide range of marketable products and services. Targeted players are often smaller firms largely interested in using their relationships with university research centers to address specific needs central to their business. They conclude this paper by discussing the implications of these findings for both industrial firms and universities     

Evaluation of a Pilot-Scale Bioscrubber for the Removal of Hydrogen Sulphide

This technical note describes an investigation on the feasibility of using treated wastewater to support the operation of a fixed-film bioscrubber for H₂S removal. A laboratory-scale fixed-film bioscrubber was assembled using Thiobacillus bacteria which were isolated from a sample of raw sludge, cultured in the laboratory, and immobilised onto the scrubber's plastic packing media by an immersion method.     

Selbstbestimmung und Selbstverständnis – Themenschwerpunkte im Umgang mit der Patientenverfügung

Ohne Zusammenfassung     

The Measurement of Plumbosolvency Propensity to Guide the Control of Lead in Tapwaters

A laboratory-scale lead-pipe rig has been developed into an accelerated test for 'plumbosolvency propensity'. High alkalinity water supplies from Anglian Water show either relatively high or low propensity characteristics which appear to be related to the form of the crystal deposit. These have been examined by scanning electron microscopy. The paper describes the uses of the test to (1) supplement random survey data, (2) investigate mixed waters, and (3) optimize orthophosphate dosing.     

The suitability of muscle of Cirrhinus mrigala in the formation of gel: a comparative electrophoretic study of six tropical carp meats

The annual inland fish production in India is 3.2 million tonnes and above. Aquaculture is around 80% of total inland fish production. The enhanced aquaculture production demands alternate processing methods for better utilisation of the farmed fish. Cirrhinus mrigala is one of the dominated species among cultured Indian major carps, but rated with lowest price. Fish meat with good gel‐forming capacity is a prerequisite in the production of fast‐moving fabricated analogue product. Cirrhinus mrigala had the highest gel strength, i.e. 435 gcm of its fresh meat in comparison with other carps. Apart from the highest protein and salt‐soluble protein nitrogen content in fresh C. mrigala meat, this article also reports that the presence of the darkest thick band of myosin heavy chain and actin in the polyacrylamide gel electrophoresis pattern of salt‐soluble extract of C. mrigala might be another possible reason for the highest gel strength in comparison with other carps. Cirrhinus mrigala contained white meat around 90%. This carp could be suitably used in the preparation of high‐valued fabricated analogue product.     

Preliminary Investigation into the Microbiological Quality of a Freshwater Bathing Site: A Case for Official Identification?

The quality of recreational waters has become of increasing importance and, where water-based activities are permitted, such waters should be required to comply with minimum standards to protect public health. At present, there are no freshwater sites in the UK which are identified as official bathing areas, despite a significant proportion being identified in other EU Member States and the increasing use of such waters for bathing. This paper presents a case for the official identification of three freshwater bathing sites which, traditionally, have been used for bathing for more than ninety years.     

Analysis of mass transfer effects in ethyl cellulose manufacture

A theoretical analysis of mass transfer effects in ethyl cellulose manufacture has been reported. This is the first model to describe a complex fluid–solid reaction in the presence of two immiscible liquids. The model derived here can be used to evaluate the dependency of the overall rate on different parameters incorporating the multiphase mass transfer effects.     

Synthesis of SiC ceramics from processed cellulosic bio-precursor

Synthesis of SiC ceramic from processed cellulosic bio-precursor was investigated. Bamboo (Bambusa tulda Roxb.) plants abundantly available in the Jorhat district of Assam, India, were selected for extraction of fibers following Kraft pulping method and bleached bamboo pulp fibers were suitably cast in the form of rectangular boards. Coir fibers available in the Alleppy district of Kerala, India, were initially digested with dilute alkali, mixed with cellulose acetate solution, air dried and then hot-pressed at 140 ± 5 °C under 2.0–2.5 MPa pressure to make rectangular boards. Well-characterized processed bio-precursors were pyrolysed at ～800 °C under flowing N₂ atmosphere to prepare the bio-carbonaceous preforms (carbon templates) which showed nearly uniform shrinkages in all directions. Coir fiber composite board carbon showed lower pyrolytic weight loss (～66%), higher density (0.49 g cm^?3), lower porosity (～58%) and narrower pore diameter (10 μm) compared to the cast bamboo pulp fiber board carbon. The carbon samples showed perfect retention of fibrous morphological features of hierarchically grown bio-structures. Ceramization of carbon templates could be done by reactive melt silicon infiltration into porous channels at ～1600 °C under vacuum. The final ceramics were adequately dense (%theoretical density > 99%), showed negligible linear dimensional changes (indicating net-dimension formation capability), presence of crystalline Si and SiC phases and duplex microstructure with complete preservation of fibrous architecture of plant bio-structure. The Si/SiC ceramic composite synthesized from coir fiber board gave room temperature 3-point flexural strength and Young's modulus values of 121 MPa and 276 GPa, respectively. Both the ceramic composites showed adequate oxidation resistance during heating at 1300 °C for 7 h in air.