Canal water, distilled

Emara [53] developed a rapid, simple, accurate and reproducible method for the quantitative determination of niclosamide ethanolamine salt (NES), the most widely used molluscicide against snail vectors of schistosomiasis, in both distilled and natural canal waters. The biocide was extracted completely from water samples by passing through Sep-Pak Ci8 cartridge and eluting the cartridge with methanol. The eluate was then analyzed directly for NES by UV Vis spectrophotometry at 330 nm [53]. 

The data from the following experiments were analyzed by least squares linear regression (8) to determine the best straight line for a first-order kinetic equation and the significance of the correlation (9). All except three of the calculated regressions had correlation coeflBcients significant at the 99% level of confidence. Exceptions were the two rate calculations in the experimental comparison of distilled vs. canal water (Case 3) and the correlation of half-life with solution depth (Case 5). 

Concentration/Time Data—Case 3 Distilled vs. Canal Water... 

Figure 3. Rate of photodecomposition of picloram. Case 3. Comparison of distilled and canal water.

Case 3 Distilled vs. Canal Water. The effect of impure water was studied by following the picloram loss from 2.07 X lO M solutions in 2.5 cm deep aluminum trays. Distilled water (pH 7) and water from the Contra Costa Canal (pH 8), Walnut Creek, Calif, were used to make the solutions. Exposure was during the month of August at Walnut Creek. 

Distilled water Canal water Bioassay BuOH/NHs Chromatography C6He/C2H3COOH/HoO Chromatography... 

Potable Water RO and NF both play a major role in providing potable water, defined either by the WHO criterion of <1000 ppm total dissolved solids (TDS) or the U.S. EPA limit of 500 ppm TDS. RO is most prominent in the Middle East and on islands where potable-water demand has outstripped natural supply. A plant awaiting startup at Al Jubail, Saudi Arabia produces over 1 mVs of fresh water (see Table 22-17). Small units are found on ships and boats. Seawater RO competes with multistage flash distillation (MSF) and multieffect distillation (MED) (see Sec. 13 Distillation ). It is too expensive to compete with conventional civil supply (canals, pipelines, w ls) in most locations. Low-pressure RO and NF compete with electrodialysis for the desalination of brackish water. The processes overlap economically, but they are sufficiently different so that the requirements of the application often favor one over the others. 

Shellfish taken from unpolluted waters have been found to contain between 1 and 12 g/g wet weight of total hydrocarbons while fish have been found to contain between 4 and 14 g/g total hydrocarbons (steam distillables) (Connell and Miller 1980). Eollowing a spill of fuel oil no. 2 in the Cape Cod Canal in... 

Figure 14.7.4. Scheme of a dry cleaning machine. 1 textiles to be cleaned, 2 cylinder, 3 cage, 4 fan, 5 heater, 6 drive for cage, 7 air canal, 8 cooler, 9 lint filter, 10 button trap, 11 filter, 12 distilling vessel, 13 pump, 14 solvent storage tanks, 15 water separator, 16 condenser, 17 steam pipe, 18 outlet to charcoal filter, 19 dosing unit. 

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