Papers by Keyword: Tap Water

Abstract: Under the aerobic condition, using tap water as solvent, the super absorbent resin was synthesized by solution polymerization of acrylic acid-sodium acrylate, The result showed the water absorbency of last production in tap water was 578g/g, when the concentration of monomer was 25%, the neutralization degree of monomer was 80%, the amount of initiator and crosslinking agent was 0.15% and 0.07% respective, the react temperature was 90°C and the time of reaction was four hours. the crosslinking action of crosslinking agent was not influenced, although tap water was used as solvent. Which will has important directive significance to the large-scale industrial production of high polymer absorbent resin.

Abstract: Number concentration of colloidal particles and concentration of several drinking water contaminants (iron, aluminium, AOX) were determined in river water, water treated at WTP, tap water and their filtrates (pore diameter of filter 60 nm). It was shown that almost all AOX were present in highly disperse state (less than 60 nm), 55...90% of iron and 55...80% of aluminium belonged to impurities with size over 60 nm. Changes of contaminants state and concentration were explained by influence of water treatment processes and corrosion of steel water distribution pipes.

Abstract: This study examined effects of various blending ratio of desalinated water and tap water on iron release. Pipe rig tests were conducted to simulate and demonstrate iron release in response to water quality changes. Results show that compare to conventional treated water, desalinated water has a pronounced effect on the iron release in ductile iron pipe; increasing fractions of desalinated water in the blends result in higher total iron release. An increase in pH from 8.0 to 10.0 after 24 hours was found due to alkaline substances (like calcium oxide) releasing from the cement mortar lining and the poor buffering capacity of desalinated water.

Abstract: Hydrargyrum(Hg) and arsenic(As) in tap water of Chongqing University Town were detected by the X-atomic fluorescence spectrometry, and the United States Environmental Protection Agency (USEPA)-supported Health Risk Assessment Model was used for evaluating the potential health risk to surrounding residents caused by Hg and As in tap water. The results showed that the average concentration of Hg and As in tap water of this region were 0.6323μg/L and 20.1237μg/L respectively, wherein the Hg content was lower than the national Standards for Drinking Quality (GB5749-2006), but the As content exceeded its stipulated level, the annual personal risk level of health hazard caused by Hg and As by the way of drinking water were 2.840×10^-8•a^-l and 1.350×10^-4•a^-l, wherein Hg would not cause apparent harm to exposure population, while As was higher than the maximum acceptable risk level by the way of drinking water（5×10^-5•a^-l）recommended by the International Committee on Radiological Protection (ICRP).

Abstract: A new method was proposed for the preconcentration/separation of zinc at trace levels using a modified organo-bentonite with dithizone (D-O-bentonite) and determined by flame atomic absorption spectrometry (FAAS). The influences of some experimental parameters including pH of the sample solution, contact time, and volume of eluent have been investigated. The influences of some matrix elements were also examined. The results show that the zinc ion could be adsorbed on the D-O-bentonite. The adsorbed quantitively was affected by the pH value of medium and contact time. In the medium of pH 4-5, the contact time was 20 min, and capacity of adsorption was 32.0 mg·g^-1. The zinc adsorbed on the sorbent could be completely eluated by using 0.5 mol·L^-1 HNO₃. The method has a good tolerance to matrix interference. The detection limit of the method for zinc ion was 0.013 µg·L^-1. The method was successfully applied to the pre-concentration/separation of zinc ion in the tap water and human urine with satisfactory results.

Abstract: A new method for the determination of traces of mercury in environmental and biological samples is described. The present methodology combines determined using a hydride generation-atomic absorption spectrometry (HG-AAS) with pre-concentration/separation of the analyte on dithizone-anchored organobentonite (D-O-bentonite). Optimal experimental conditions for the adsorption of the Hg, including pH, contact time, eluent concentration and volume and co-existing ions have been studied. The result showed that the mercury could be adsorbed on the D-O-bentonite. The adsorbed quantitively was affected by the pH value of medium and contact time. In the medium of pH 5.0, the adsorption time was 15 min, and capacity of adsorption was 23.2 mg·g^-1. The mercury adsorbed on the sorbent could be completely eluated by using 3 mol·L^-1 HCl. The adsorption agent has been applied to the pre-concentration/separation of mercury in surface water and human hair samples with satisfied results.

Abstract: Ion chromatography (IC) has been developed for the simultaneous analysis of cations and anions in the water, food, atmosphere, etc. Chromatography can yield the precise and reproducible data if the experimental condition is kept constant. In the present studies, the major cations and anions in the tap water were determined with the technique of IC. A Dionex ICS-2000 ion chromatograph with a Dionex gradient pump, eluent degassing module and conductivity detector was used. Cations were separated on a CS12 A ion-exchange column, with a CG-12 A guard column, and detected after suppression with CSRS 300 cation electrical self-regenerating suppressor. Anions were separated on an AS 11 HC ion-exchange column, with an AS 11 HC guard column, and detected after suppression with an ASRS 300 anion electrical self-regenerating suppressor. The results indicated that the technique of IC was suitable for the rapid, precise and accurate determination of major cations and anions in the tap water samples. In addition, the acceptable detection limits were obtained for all the cations and anions, and the time of analysis was significantly shortened with the technique of IC.

Abstract: Effect of activating device on the property of tap water was studied by surface tensiometer and pH meter. The results showed that the surface tension of tap water activated by the device reduced and pH value increased. The variations of surface tension and pH value are connected with flow rates. The larger flow rate, the less variation of surface tension and pH value when at the same cycle time, however, the more variation of surface tension and pH value when at the same activating time. Activated by the device, 17O NMR half width of tap water reduced from 70.79Hz at the inlet to 60.87Hz at the outlet. Reduction of surface tension were caused by hydrogen bonds in water clusters which were weakened or broken by far-infrared radiation of functional ceramic ball and galvanic cell action of copper-zinc alloy. Increment of pH value were caused by H+ in water exchanging with metal cations on surface of far-infrared ceramic balls and dissolved oxygen getting electron and forming OH-1 with the function of copper-zinc alloy.

Abstract: In order to realize electrochemical finishing in tap water, an ultrasonic vibration using a transducer enabling three kinds of vibration modes, i.e., axial, bending, and complex, was given to the electrode. During the test finishing, it was observed that with electrode without ultrasonic vibration, the workpiece surface was simply covered with the rust. On the contrary, by applying the ultrasonic vibration of bending vibration mode or complex vibration mode with an appropriate amplitude, the material removal rate was increased and the surface roughness was improved.