Showing papers on "Distilled water published in 1989"

Viability of Giardia cysts suspended in lake, river, and tap water

Abstract: Numerous waterborne outbreaks of giardiasis have occurred since 1965, yet little or no information has been reported on the viability of Giardia cysts in different aquatic environments. We have studied the viability of Giardia muris cysts suspended in lake, river, and tap water, while also monitoring water temperature, dissolved oxygen, pH, and other water quality parameters. Fecal pellets containing G. muris cysts were placed in glass vials covered with filter paper and exposed to (i) lake water at 15 ft (ca. 4.6 m) and 30 ft (ca. 9.2 m), (ii) river water, (iii) tap water, and (iv) distilled water stored under laboratory conditions. At 3, 7, 14, 28, 56, and 84 days, two vials from each environment were removed, and cyst viability was determined by (i) fluorogenic dye exclusion, (ii) production of giardiasis in an animal, and (iii) cyst morphology by Nomarski microscopy. In the fall, the cysts suspended at 30 ft in lake water remained viable for up to 56 days whereas cysts stored at 15 ft were nonviable after day 28. The G. muris cysts exposed to river water remained viable up to 28 days as determined by the production of giardiasis in mice. G. muris cysts suspended in tap water showed no signs of viability after 14 days, while cysts serving as controls (exposed to refrigerated distilled water) remained viable for up to 56 days. In the winter, Giardia cysts suspended in either lake or river water were viable for 56 to 84 days whereas cysts exposed to tap water were nonviable by day 14.(ABSTRACT TRUNCATED AT 250 WORDS)

Effect of heat and ultrasonic waves on the survival of two strains of Bacillus subtilis.

Abstract: The combined effect of ultrasonic (20 KHz, 150 W) and heat treatment on the survival of two strains of Bacillus subtilis in three suspending media (distilled water, glycerol and milk) has been studied When spores suspended in water or milk were subjected to ultrasonic waves before heat treatments a little or no decrease of the heat resistance was observed However, both sporicidal agents applied simultaneously (thermo-ultrasonication) decreased by 63% (B subtilis, var niger-40) and 74% (B subtilis ATCC 6051) the decimal reduction times for the heat treatment when the spores were suspended in glycerol and by 79% and 40%, respectively when suspended in milk The thermo-ultrasonication of spores in water markedly reduced the heat resistance of them (between 999% and 70%) in the range 70-95 degrees C but the effect of the thermo-ultrasonication significantly diminished as the temperature of the treatment was approached to the boiling point of the water

Microbiological, chemical, and physical changes in fresh, vacuum-packaged pork treated with organic acids and salts.

Abstract: The effects of selected organic acids and salts on microbial numbers, pH, exudate, and color were studied for vacuum-packaged, fresh pork chops. Pork chops were dipped for 2 min in (v/v) 1% acetic acid, 1% acetic/1% lactic acid, 1.5% acetic/1.5% sodium acetate, 3% acetic/3% sodium ascorbate, 3% acetic/2% NaCl or sterile, distilled water before being vacuum-packaged and stored at 2 degrees-4 degrees C for 6 weeks. Treatments containing 3% acid resulted in lower aerobic microbial numbers (P less than 0.05) and effectively inhibited Enterobacteriaceae. Treatments containing 1% acetic acid, with or without 1% lactic acid, were ineffective. All acid treatments increased exudate and were detrimental to meat color (P less than 0.05) although sodium ascorbate reduced color damage. Chops treated with 3% acetic acid/3% sodium ascorbate had the highest Hunter a and L color scores.

Water based ink for ink-jet printing

Abstract: Water based ink for ink-jet printing, consisting of: 05-8 wt % water soluble dye 1-64 wt % glycol 001-5 wt % wetting agent 001-20 wt % preservative, pH-regulator, complexing agents and/or other additives, as well as distilled water, where glycol consists of triethylene glycol or a mixture of triethylene glycol and ethylene glycol and the wetting agent is a formulation of the following structure ##STR1## where R=OH or R=(O--CH 2 --CH 2 ) n --OH with n=1 to 30

A Laboratory Study of the Leaching of Lead From Water Faucets

Abstract: A test-pilot system was constructed to evaluate lead leaching from 12 different kitchen faucets. A storage tank, pressure pump, and manifold system was operated to simulate, as closely as possible, the use of the faucets in a household plumbing system. Leaching of lead from the faucets was determined for detention times ranging from 30 minutes up to 34 days using distilled water, a very aggressive water, and Cincinnati tap water, a nonaggressive water. Various sampling procedures were used to evaluate the impact of sample size and to determine the flushing volume needed to remove most of the lead from a faucet. The highest lead levels were found in the first 125-mL samples from the faucets made from cast brass and exposed to the aggressive distilled water. Subsequent samples had lower levels with background levels achieved after flushing with about 500 mL to liter of water. Lead levels are dependent on detention time, but the most significant increase occurs during the first few hours of water contact.

Improvement of the photostability of selected substances in aqueous medium

Abstract: The photodegradation of some pesticides in water has been investigated. The kinetics of the photochemical processes is discussed and the photolytic half‐life is calculated. The objective of this paper is to present some of the recent results on the kinetics and on the products of sunlight‐induced reactions of Parathion, Gardona, Diazinon, Atrazine and Phenmediphame at low concentrations in distilled water and fresh water. The quantum yield, measured at 263 nm for Phenmediphame in aerated water at 5 × 10‐4 M and 30°C, was 1.4 × 10‐2, and for Parathion, measured at 300 nm in aqueous solution at 3.42 M at pH 6.4 and 25 °C, was 1.5 × 10‐3. The measured absorption spectra and the variable light intensity were used to estimate the environental phototransformation process and the persistence of these compounds in water.

Intraparticle diffusion of phenols within bidispersed macroreticular resin particles.

Abstract: Uptake curves were obtained for phenol, p-chlorophenol and p-nitrophenol/XAD-2000 resin systems using a shallow-bed method for various concentration ranges at 288.2, 298.2, 308.2 and 318.2 K. Both distilled water and a 20% aqeuous solution of isopropanol were employed as solvents, to vary the molecular diffusivity of the solutes. The values of effective intraparticle diffusivity were determined by comparing experimental and theoretical uptake curves. The values obtained for both solvents, i.e., distilled water and propanol/water mixture systems, were not dependent on the amount adsorbed in the higher concentration range. Those results show that, except in the region where there is a low adsorbed amount, an adsorber packed with macroreticular resin particles can be designed using a traditional pore diffusion model.

Heavy duty liquid laundry detergents containing anionic and nonionic surfactant, builder and proteolytic enzyme

Abstract: Heavy duty liquid laundry detergent compositions containing synthetic anionic and ethoxylated nonionic surfactant, detergency builder, specific proteolytic enzyme, an enzyme stabilization system, and water are disclosed. The compositions have a pH in a 10% by weight solution in water at 20°C of between about 7.0 and 9.0, a Critical Micelle Concentration of less than or equal to about 200 ppm, and an air/water Interfacial Tension above the Critical Micelle Concentration of less than or equal to about 32 dynes/cm at 35°C in distilled water. The compositions are preferably clear, homogeneous, stable, and provide good cleaning performance, particularly through-the-wash on enzyme-sensitive stains.

Cation type and ionic strength effects on the solution composition of an acidic subsoil

Abstract: SUMMARY Sodium, potassium, magnesium and calcium chloride solutions of four concentrations (0.4, 1.0, 4.0, l0.0meq dm−3) and distilled water were equilibrated with the highly weathered, acidic subsoil of a Plinthic Paleudult from Natal at a soil:solution ratio of 2.2:1, then separated by centrifugation with an immiscible liquid and analysed for inorganic solutes. With each salt, increasing ionic strength resulted in lower solution-pH (the maximum pH was 4.95 in the distilled water equilibration) and higher aluminium concentration and activity. These effects were much less marked for sodium (maximum ΔpH of 0.47) than for the other cations (maximum ΔpH of 0.83) and both the concentration and activity of aluminium were correspondingly lower (by tenfold at the highest chloride concentration) in the sodium solutions. Irrespective of the nature or concentration of the electrolyte added, pH and the activities of A13+ and silica in solution were consistently interrelated in a way which suggests that equilibrium with the gibbsite and poorly crystalline kaolinite in this soil had been closely approached. The results provide a basis for anticipating the effect of infiltrating solutions of fertilizer salts on subsoil acidity and suggest that a beneficial effect may accrue from the presence of sodium in the cation suite of acid soils.

Determination of cadmium, copper, iron, manganese, lead and zinc in sewage sludges with prior acid digestion in a microwave oven and slurry introduction

Abstract: A method is proposed for the determination of six elements in sewage sludges by flame atomic absorption spectrometry. The recommended procedure consists of introducing 500 mg of sample, 5 ml of HNO3 and two drops of 2-ethylhexan-1-ol into a 100-ml Pyrex reaction vessel, which is then hermetically sealed and introduced into a microwave oven; and the contents digested for 3 min at a power of 520 W. After digestion the residue is allowed to cool and is then diluted with distilled water. The resulting slurries of the digested samples in water are introduced directly into the flame using multi-elemental aqueous solutions as standards. The variables of the digestion procedure in the microwave oven, such as power, time, sample mass and acid volume, have been studied and the validity of the conditions for using aqueous standards in the analysis of slurries has been evaluated. The proposed method has been applied to the analysis of certified sewage sludge samples and the analytical parameters of the method have been evaluated.

Sulfur Analysis of the Sediment by the H2O2 Treatment-Turbidimetric Method

Abstract: Sedimentary sulfur mainly of FeS2 (pyrite) was oxidized to sulfate with 30% H2O2 and the concentration of sulfate was determined by the turbidimetric method.Treatment procedures were as follows.1) Wet sediment (approximately 0.3g) was washed twice with distilled water followed by centrifugation (3, 000rpm, 15mins), and dried at 80°C.2) The dry sample (0.1g) was reacted with 10ml 30% H2O2 for 30mins at room temperature and then for 2mins at 90-100°C.3) When oxidation reaction ceased (usually after 15hrs), 50ml distilled water was added and the sample filtered through a 0.45μm membrane filter to separate extract from residue. Filtrate was rinsed and brought to 100ml volume with distilled water for the turbidimetric method.The content of sedimentary sulfur determined by this method was much higher in the marine and brackish water sediments than in the freshwater sediments. The vertical variation in sulfur content was in good agreement with the succession of diatom assemblages. As a sulfur analysis indicative of paleoenvironmental changes, this method is considered useful for its simplicity and for the small amount of sample used.

Preparation with an anti-inflammatory, lactogenous and stimulating action, and method of obtaining it

Abstract: A preparation with an anti-inflammatory, lactogenous and stimulating action consists of a water emulsion of human placental chorion denatured by chlorine having a pH of 2.5 to 3.0 and a solid-particle size not exceeding 0.4 mm, a solid residue of 1.70 to 2.3 % by weight, and containing, per 1 ml, no less than 0.05 mg of nucleic acids, no less than 6.0 mg of protein and no less than 0.30 mg of hexuronic acids. A method of obtaining said preparation consists in that the placenta chorion is washed, disintergrated then denatured by treating it with a solution of chlorine in distilled water at a concentration of the chlorine not exceeding 0.21 % by weight, after which the obtained tissue mass is separated from the solution, treated with distilled water until a pH of 3.0 is obtained and, after separation from the water, mixed again with the distilled water and dispersed up to a particle size not exceeding 0.4 mm.

Solubility of zinc oxide-eugenol and calcium hydroxide cements in simulated dentinal fluid

Abstract: The solubility of four dental cement bases was measured in simulated dentinal fluid and distilled water to evaluate the relevancy of the American Dental Association solubility test for cement bases in contact with vital dentine. A simulated dentinal fluid was formulated utilizing glucose, distilled water, and sterile human plasma. Cement-base samples were immersed in either distilled water or simulated dentinal fluid at 37 degrees C in a shaker water-bath for 1, 2, or 3 months. Weight loss values were compared utilizing a three-way analysis of variance. Zinc oxide-eugenol cements were significantly more soluble in simulated dentinal fluid than distilled water, while the calcium hydroxide cement bases were significantly more soluble in distilled water than simulated dentinal fluid.

Inorganic ion-exchangers for the removal of zirconium, hafnium and niobium radioisotopes from aqueous solutions

Abstract: Studies were made on the uptake of zirconium, hafnium and niobium isotopes onto zeolites and amorphous zirconium phosphate. Ion exchange capacities and distribution coefficients were determined and the influence of pH examined. Kinetic experiments were made to determine the rates of uptake of the radioisotopes on the exchangers and to measure the leaching of isotopes from preloaded exchangers by synthetic sea water, simulated pond water and distilled water.

Reagent for diagnosis of cancer

Abstract: The invention provides a reagent composition for cancer diagnosis which is composed of mercury, nickel, nitric acid and distilled water. The nickel is contained in an amount of 0.05 to 0.5 parts by weight per one part by weight of mercury.

Method and apparatus for the batch distillation of water

Abstract: A method and apparatus for automatically and sequentially distilling batches of water having substantially equal volumes in a plurality of distillation cycles, one batch in each cycle. During each cycle, water is admitted to a boiler tank for a fixed interval of time to form a batch in the tank. The batch of water in the tank is then vigorously boiled while venting the tank through a pipe to the atmosphere. The vigorous boiling is terminated when the temperature within the vent pipe reaches the boiling point of pure water. Upon termination of the vigorous boiling phase, a gentle boiling phase is initiated, the vent pipe is closed, and vapor in the tank is admitted to a condenser. The condenser condenses the vapor to obtain distilled water which is collected in a collection device. The gentle boiling phase continues until the level of water in the tank recedes to the level of a heater in the tank. At this time the heater is turned off and a drain valve opened to drain the water and residue remaining in the tank. After the tank is drained, water is again admitted to the tank for a fixed interval of time while the drain is kept open, thus flushing residues from the tank. After the flush water has drained from the tank, the drain is closed and a new distillation cycle is initiated.

Measurement of the Deposition and Fate of Sulfur-Dioxide-35 in a Pine Plantation

Abstract: The average deposition velocity for the entire leaf surface of the pine plantation was 0.0041 m/s. The fresh whole needles were rinsed in distilled water. About 50% of the 35 S activity was removed by the water rinse. About one-third, 30 to 38%, of the 35 S activity remaining after washing was found in each of the two extracts and about one-third in the residual material left after extraction

Evaluation of Henry's constant for H2S in water and sewage effluents

Abstract: An experimental set‐up was used to evaluate Henry's constant (H) of H2S in distilled water and one of the sewage treatment plants in Kuwait. Calculated values of (H) for H2S in distilled water were found to agree with published works. For sewage, (H) was found to have a mean value of 601 atm/mole fraction for a temperature range of 20°C to 40°C. Factors affected the value of (H) in sewage were: initial concentration, flow rate of stripping fluid, pH, and pK. Effect of each factor was investigated and results were correlated.