Natural clinoptilolite composite membranes on tubular stainless steel supports for water softening.

Disk membranes generated from high-purity natural clinoptilolite mineral rock have shown promising water desalination and de-oiling performance. In order to scale up production of these types of membranes for industrial wastewater treatment applications, a coating strategy was devised. A composite mixture of natural clinoptilolite from St. Cloud (Winston, NM, USA) and aluminum phosphate was deposited on the inner surface of porous stainless steel tubes by the slip casting technique. The commercial porous stainless steel tubes were pre-coated with a TiO2 layer of about 10 µm. Phase composition and morphology of the coating materials were investigated using X-ray diffraction and scanning electron microscopy. Water softening performance of the fabricated membranes was evaluated using Edmonton (Alberta, Canada) municipal tap water as feed source. Preliminary experimental results show a high water flux of 7.7 kg/(m(2) h) and 75% reduction of hardness and conductivity in a once-through membrane process at 95 °C and feed pressure of 780 kPa. These results show that natural zeolite coated, stainless steel tubular membranes have high potential for large-scale purification of oil sands steam-assisted gravity drainage water at high temperature and pressure requirements.

Enzyme catalyzed electricity-driven water softening system.

Hardness in water, which is caused by divalent cations such as calcium and magnesium ions, presents a major water quality problem. Because hard water must be softened before use in residential applications, there is great interest in the saltless water softening process because, unlike ion exchange softeners, it does not introduce additional ions into water. In this study, a saltless hardness removal driven by bioelectrochemical energy produced through enzymatic oxidation of glucose was proposed and investigated. Glucose dehydrogenase was coated on a carbon electrode to catalyze glucose oxidation in the presence of NAD⁺ as a cofactor/mediator and methylene green as an electrocatalyst. The results showed that electricity generation stimulated hardness removal compared with non-electricity conditions. The enzymatic water softener worked upon a 6h batch operation per day for eight days, and achieved an average hardness removal of 46% at a high initial concentration of 800 mg/L as CaCO3. More hardness was removed at a lower initial concentration. For instance, at 200mg/L as CaCO3 the enzymatic water softener removed 76.4±4.6% of total hardness. The presence of magnesium ions decreased hardness removal because of its larger hydrated radius than calcium ions. The enzymatic water softener removed 70-80% of total hardness from three actual hard water samples. These results demonstrated a proof-of-concept that enzyme catalyzed electricity generation can be used to soften hard water.

A multicentre randomized controlled trial of ion-exchange water softeners for the treatment of eczema in children: protocol for the Softened Water Eczema Trial (SWET) (ISRCTN: 71423189).

BACKGROUND: There is epidemiological evidence linking increased water hardness with increased eczema prevalence. A number of plausible mechanisms can be forwarded to suggest why hard water could exacerbate eczema. The most likely explanation is increased soap usage in hard water areas, the deposits of which can cause skin irritation in individuals with eczema. OBJECTIVES: To assess the cost and cost-effectiveness of ion-exchange water softeners for the treatment of eczema in children. PATIENTS/METHODS: Three hundred and ten children aged 6 months to 16 years, with moderate to severe eczema. The children must live in hard water areas (>or= 200 mg L(-1) of calcium carbonate) and have a home that is suitable for the installation of a water softener. This is a single-blind, parallel-group, randomized controlled trial of 12 weeks duration followed by a 4-week cross-over period. RESULTS/ANALYSIS PLAN: PRIMARY OUTCOME: difference in the mean change in disease severity (Six Area, Six Sign Atopic Dermatitis score) at 12 weeks compared with baseline. SECONDARY OUTCOMES: (i) proportion of time spent moving during the night; (ii) self-reported global changes in eczema severity; (iii) amount of topical treatment used; (iv) Patient Oriented Eczema Measure; (v) number of totally controlled and well controlled weeks; (vi) impact on health-related quality of life for the child (EQ-5D) and the family (Dermatitis Family Impact questionnaire); and (vii) cost-effectiveness. It is planned that recruitment will be completed by the end of 2008 and results will be available towards the end of 2009.

Water treatment for hemodialysis--updated to include the latest AAMI standards for dialysate (RD52: 2004) continuing.

While nurses may not routinely service the water treatment system or mix the dialysate, they are responsible for understanding all the clinical ramifications of water and dialysate for HD and helping to piece together the entire treatment picture. Although historically the water treatment system has been in the technicians' domain, knowing the technical aspects is important in order for the entire team to work together toward the patients' ultimate well being. This article describes the composition of water treatment systems for hemodialysis as well as the monitoring and testing necessary to assure that both water and dialysate are safe for patient use.

A multi-purpose system for water purification and sea-water softening.

A novel technique that can be used for reacting toxic carbon dioxide (CO2) emissions from power plants and other combustion wastes with sea water is described. A chemical interaction between CO2 and the cations in sea water, with the pH electrolytically regulated, can precipitate almost all the calcium and magnesium ions, as well as some sodium and potassium ions, as carbonates and bicarbonates. The carbonates and bicarbonates thus prepared can then be mixed with ash to yield a building material. Sulfur ions will be neutralized with calcium and magnesium, and the remaining ions can be removed using reverse osmosis or some other method. The technology and equipment for purification are based on modules that can be used for industrial waste-water, sea water, solutions, and otherwise. The module for separation of sand and suspended coarse substances consists of a tank for flocculation, coagulation, and precipitation of solid particles; and a low-pressure hydrocyclone. The module for purification from oil and fine suspensions is based on column flotation, flotation with a special ejector, and adhesion flotation. The module for ions and colloids consists of an absorbing filter with zeolite, fly ash, and other absorbing materials. Using a laboratory model consisting of a special mini-plant, we processed 10 L of factory-waste water containing more than 20 g/L organic content (compare with the upper limit of 0.02 g/L allowed by the Ministry of Environmental Protection in Israel). After the experimental solution was treated and evaporated to a small bulk, the water obtained was almost clear. On the basis of the results in the model, we present a scaled-up process for the design, development, and production of equipment for and the assembly of a large installation for drainage and water purification.

[Preparation of water at kidney centers using separating counterosmosis equipment]. / Vodopodgotovka v pochechnykh tsentrakh s ispo'lzovaniem razdeli- te'lnykh obratnoosmoticheskikh apparatov.

A water treatment AKBA-I unit intended for the renal centers was tried. The unit includes a clarifier, an adsorber, a softener, a reflux osmotic separator and electronic systems for the control of hydrodynamic processes. The trials demonstrated the unit to be highly effective as regards the removal from water of salts of hardness, of iron, potassium, oxidizable substances and active chlorine. The pH value of the filtrate (7.1-7.4) appeared to meet the requirements made during the preparation of a dialyzing solution. The concentration of sodium ions in the filtrate was 0.75 mg.eq/l, which did not influence the concentration of sodium ions in the dailyzing solution during its preparation from dry concentrate. During operation of the unit, the selectivity of the APO membrane in the operating mode was defined. It amounted to 85%.

Evaluation report: dialysis and ancillary equipment.

As part of the continuing programme of evaluation of medical equipment sponsored by the UK Health Departments, the evaluation of dialysis and ancillary equipment is being carried out within the University of Sheffield, under the direction of Professor M. M. Black. 'Health Equipment Information' Number 148, published in December 1985, carries full reports on the Cobe Centry 2Rx haemodialysis system with double blood pump module (DBPM), the Lucas Medical 2100 haemodialysis system, and the Permutit Series 8 water softener. It also contains summaries of full reports on the Organon-Teknika Sorbsystem and Cordis-Dow Seratron haemodialysis systems, and the Gordonsal RD500 and Elga Mediro D water softeners, which were published in 'HEI' 136. Readers should note that the Cordis Seratron and Lucas 2100 models are no longer available in the UK. Extracts of the evaluations of the Cobe Centry 2Rx + DBPM and the Permutit Series B models, together with summaries and overall comparisons, are given below. 'HEI' (ISSN 0261-0736) is free to NHS staff and 5.00 pounds/copy to others. Editorial enquiries to DHSS Scientific and Technical Branch, 14 Russell Square, London WC1B 5EP.

Dialysate delivery: historical, theoretical, and practical aspect.

Maintenance hemodialysis has progressed from a tentative therapy for a few patients in Seattle to a generally available treatment sustaining 100,000 patients around the world. The technical principles of dialysis are sufficiently understood to permit fabrication of disposable dialyzers in sheet, coil, or hollow-fiber configuration. Dialysate delivery systems can serve either single patients or groups of patients with high efficiency. Reduction in size of single-parent systems by incorporation of dialysate regeneration or miniaturization of components in a suitcase will promote patient mobility.

Dialysis anaemia caused by subacute zinc toxicity.

Nine out of ten patients dialysed in a satellite dialysis unit became severely anaemic over a 2-month period. The onset of anaemia coincided with the installation of a new galvanised-iron water softener in the dialysate water-supply system. An activated carbon filter was installed and haemoglobin levels returned towards previous values. Two patients on home dialysis showed similar falls in haemoglobin after the installation of galvanised iron piping in their dialysate water-supply systems; these problems also resolved after carbon filtration of the dialysis water. It is suggested that elution of zinc from galvanised iron can cause anaemia in dialysis patients. Carbon filtration removes of 95-99% of the zinc eluted.

Cincuenta años de progreso en materia de purificación del agua en Estados Unidos / Fifty years of progress in water supply purification in the United States of America

Narra el autor los hechos más salientes del medio siglo de progreso de los servicios de abastecimiento de agua potable ocurridos en el medio siglo que culmina en 1913, o sea, en el lapso de 1863 a 1913, si bien otros acontecimientos y progreso de fecha reciente entran de cuando en cuando en el relato con fines aclaratorios, a modo de contraste o para sacar lecciones necesarias

Los próximos cincuenta años en materia de purificación del agua / The next fifty years in water supply purification

Basándose en la historia del abastecimiento de agua potable en Estados Unidos, en su estado presente, y en los problemas del desenvolvimiento industrial y otros elementos de contaminación, como los detergentes, las radiaciones ionizantes, etc., el autor vaticina los adelantos que cabe esperar en materia de purificación del agua en los próximos cincuenta años