Vanadium(V) removal from aqueous solution and real wastewater using quaternized pine sawdust.

Cross-linked and quaternized pine sawdust was tested for vanadium removal from a synthetic aqueous solution as well as from real industrial wastewater which had a considerable amount of vanadium and other ions such as sulphate, ammonium and nickel. The maximum vanadium sorption capacity of the modified pine sawdust was found to be 130 mg/g in synthetic solution and 103 mg/g in real wastewater. Modified pine sawdust worked well over a wide range of pH. Column studies with real wastewater proved that vanadium was efficiently desorbed from the material with 2 M NaOH and that the material could be reused.

Analysis of pharmaceuticals, hormones and bacterial communities in a municipal wastewater treatment plant - Comparison of parallel full-scale membrane bioreactor and activated sludge systems.

In this study, the occurrence of pharmaceuticals, hormones and bacterial community structures was studied at a wastewater treatment plant in Finland having two different parallel treatment lines: conventional activated sludge (CAS) treatment with a sedimentation stage, and a membrane bioreactor (MBR). Influent and effluents were sampled seven times over a period of one year. The bacterial communities of the influent samples showed a high degree of similarity, except for the February sample which had substantially lower diversity. There was significant fluctuation in the species richness and diversity of the effluent samples, although both effluents showed a similar trend. A marked decrease in diversity was observed in effluents collected between August and November. The initiation of nitrogen removal as a result of an increase in temperature could explain the changes in microbial community structures. In overall terms, suspended solids, bacteria and total organic matter (COD and BOD) were removed to a greater extent using the MBR, while higher Tot-N, Tot-P and nitrate removal rates were achieved using the CAS treatment. Estrone (E1) concentrations were also consistently at a lower level in the MBR effluents (<0.1-0.68 ng/l) compared to the CAS effluents (1.1-12 ng/l). Due to the high variation in the concentrations of pharmaceuticals, no clear superiority of either process could be demonstrated with certainty. The study highlights the importance of long-term sampling campaigns to detect variations effectively.

Coagulation of wood extractives in chemical pulp bleaching filtrate by cationic polyelectrolytes.

The purpose of this research was to investigate the effectiveness of short-chain cationic polyelectrolytes of different molecular weights and charge densities in reducing turbidity and selectively removing toxic wood extractives from chemical birch pulp filtrate. The effects of chemical type, dosage and temperature were of interest. An effective performance was achieved with a copolymer of acrylamide and methacrylate of medium molecular weight and medium charge density at 72 degrees C and pH 5-6. The dosage range optimum for reducing the turbidity was 102-142 mg/L. Up to 92% of the wood extractives was selectively removed.

Investigation of multimodal zeta potential and size distribution in chemical pulp process water.

Multimodal zeta potential distribution in chemical birch pulp process water was studied by filtrating the water into fractions and subsequently measuring zeta potential, charge quantity, turbidity and organic substances. Filtrations were made using 12 microm, 1.6 microm, 1.2 microm, 0.45 microm and 0.1 microm membranes. The number of populations with different zeta potentials diminished with filtration. With the unfiltrated water, 12 microm and 1.6 microm filtrates, three or four different zeta potentials were observed. When the filtration was performed with a 1.2 microm membrane or smaller, only two populations of different zeta potentials were detected. The charge quantity steadily approached zero from unfiltrated water towards a 1.6 microm fraction filtrate. After that, it remained constant. Turbidity constantly decreased when using smaller membranes. The amount of wood extractives decreased to half with 0.1 microm filtration. No significant difference in the amount of carbohydrates and lignin between the filtrated fractions and the unfiltrated water was detected. A comparison dealing with particle size analysis between two different apparatuses was also made.

Thermography in diagnosing deep venous thrombosis of the lower limb.

Phlebography and thermography of the lower limbs were performed on 58 patients suspected on the basis of clinical examination to have deep venous thrombosis of the lower limb. Both thermography and phlebography were consistently positive in 34 and negative in 17 cases. The skin temperature was lowered in four cases evidently because of an arterial spasm caused by deep venous thrombosis. No significant temperature elevation was established in three anamnestically and phlebographically older cases.

Yeast bezoar formation following gastric surgery.

Yeast bezoar seems to be a relatively common late complication after various gastric operations. The incidence of bezoar depends decisively on the nature of the operation. Vagotomy in particular is conducive to the formation of a bezoar. Vagotomy + Billroth I resection proveded the most propitious conditions for the growth of yeast, for every one-half of the patients in this group developed a bezoar. Yeast bezoars usually appear within a year of the operation. The majority disappear during the first follow-up year, many without any therapy. However, in some cases the bezoar was a rather inconvenient late complication of gastric surgery and one that gave symptoms. It is difficult to draw any definite conclusions concerning the effect of therapy on the disappearance of the bezoar. We used gastric lavage and antimycotics as well as substances that increase gastric acidity. There is still no known method of preventing the formation of yeast bezoars. In the present consensus, a change in the acid conditions and disturbed gastric motility postoperatively are conducive to the formation of a bezoar.

Radiographic versus direct measurements of the spinal canal at lumbar vertebrae L3-L5 and their relations to age and body stature.

The role of the narrow lumbar spinal canal in back and sciatic pain is well established. The accuracy of measurements obtained from lumbar radiographs was therefore analyzed in lumbar spine specimens taken from 132 male cadavers. After removal of soft tissues, the same distances were measured on the bones of 80 specimens. Comparisons were made after correction for magnification, the radiographic measurements of interpedicular distances being, on average, 2 mm greater at L3 than the osteologic ones and 4 mm greater at L5. Interarticular distances, midsagittal diameters, and pedicular lengths were, on average, 1 mm greater and foraminal anteroposterior measurements 1 mm less than the osteologic ones. Body stature correlated with interpedicular and interarticular distances, pedicular length, and foraminal anteroposterior measurements. In older age groups, the midsagittal diameter tended to be reduced. A number of correlations were found between the five measurements, e.g. between the anteroposterior diameter of the intervertebral foramen and the pedicular length. Measurements in the transverse plane were independent of those in the anteroposterior plane. These results confirm and amplify preliminary observations and indicate the potential value of simple measurements on lumbar spine films as an alternative to more sophisticated and expensive radiologic investigations.