摘要:

The author of this letter to the editor details Canadian experience with the use of biological treatment for water purification. In a study designed to come up with parameters for new filtration facilities in Markam Township, Ontario, it was learned that filters without prechlorination had been removing an organic precursor to a strong chloroflavor problem. This study seemed to verify that biological growths absorb those substances that are most biologically accumulative. The new aeration‐plus‐pressure filter plant designed at 5 Igpm/sq ft successfully removed the chloroflavor. The author emphasizes the relative value of organic stabilization compared with the nitrification aspects of an earlier article by Rittman and Snoeyink entitled, “Achieving Biologically Stable Drinking Water” in the October 1984 Journal American Water Works Association. In another instance, a red water problem in the community of Brooklin, Ontario, was cleared up by reverting from prechlorination to postchlorination at the iron removal filter and by restoring the original prefilter air injection.

ISSN:0003-150X    

DOI:10.1002/j.1551-8833.1985.tb05513.x

出版商:Wiley    

年代:1985

数据来源: WILEY

摘要:

In this letter to the editor, the author questions a statement by James C. Plutze in a feature entitled Viewpoint in the December 1984 Journal American Water Works Association that filtration is known to remove Giardia and that only minimal doses of chlorine are needed. He emphasizes the need for adequate disinfection and calls for industry guidelines for disinfection emphasizing postfiltration chlorination with partial dechlorination.

ISSN:0003-150X    

DOI:10.1002/j.1551-8833.1985.tb05514.x

出版商:Wiley    

年代:1985

数据来源: WILEY

摘要:

A Pennsylvania court ruled that a company that had purchased a water system from a developer had not assumed the liabilities of the developer and could not be required to refund fees collected by the former.

ISSN:0003-150X    

DOI:10.1002/j.1551-8833.1985.tb05517.x

出版商:Wiley    

年代:1985

数据来源: WILEY

ISSN:0003-150X    

DOI:10.1002/j.1551-8833.1985.tb05519.x

出版商:Wiley    

年代:1985

数据来源: WILEY

摘要:

Research findings from 1946 to 1984 concerning the formation of trihalomethanes from chlorine‐bromide, chlorine dioxide‐bromide, and monochloramine‐bromide are summarized. Areas of incomplete information are identified, and a complete list of references is provided.

ISSN:0003-150X    

DOI:10.1002/j.1551-8833.1985.tb05520.x

出版商:Wiley    

年代:1985

数据来源: WILEY

摘要:

UV absorbance at 254 nm is an excellent surrogate parameter for estimating the raw water concentrations of organic carbon (NPTOC—nonpurgeable total organic carbon) and THM precursors (TTHMFP—total trihalomethane formation potential) in the Grasse River (highly colored water) and the Glenmore Reservoir (protected, upland source). The raw water surrogate equations developed from the Grasse River data were tested successfully on other waters. Direct filtration pilot‐plant data demonstrated that UV can be used to monitor pilot‐plant performance for removals of NPTOC and THM precursors. For two plants studied, UV was an excellent predictor of plant performance for removals of NPTOC and THM precursors. Instantaneous TTHMs of the finished waters can be predicted from raw water UV, finished water pH, chlorine consumption, and temperature data. Particular attention should be given to the selection of sampling locations and to the sample‐handling conditions.

ISSN:0003-150X    

DOI:10.1002/j.1551-8833.1985.tb05521.x

出版商:Wiley    

年代:1985

数据来源: WILEY

摘要:

Alum coagulation and lime softening exhibited variable effectiveness for removing the total organic carbon (TOC) associated with humic substances in water supplies. Pretreatment with alum or lime also affected the subsequent adsorption of TOC by granular activated carbon, with alum coagulation generally improving overall adsorbability. The effectiveness of pretreatment for removing TOC and for altering the adsorption characteristics of residual humics appears to depend on the source and type of the humic material.

ISSN:0003-150X    

DOI:10.1002/j.1551-8833.1985.tb05522.x

出版商:Wiley    

年代:1985

数据来源: WILEY

摘要:

In process design for air stripping of trihalomethanes (THMs) the gas‐phase, mass‐transfer resistance must be taken into account to ensure efficient operation. In most cases, it should be possible to attain effective THM control with an energy expenditure of less than 0.1 kW · h/m3of treated water. Mechanical surface aeration and countercurrent, packed‐column air stripping require approximately the same amounts of energy to achieve the same treatment efficiency. Considerable energy savings can be realized by choosing a multistage configuration in surface aeration.

ISSN:0003-150X    

DOI:10.1002/j.1551-8833.1985.tb05523.x

出版商:Wiley    

年代:1985

数据来源: WILEY

摘要:

Currently, the most popular method of analyzing total organic halide in water involves carbon adsorption, oxidative combustion, and measurement of the hydrogen halide by microcoulometry. Total organic halide can be used as an indicator of water quality, providing a direct measure of disinfection by‐product formation and, in some circumstances, a surrogate measure of individual organic pollutants. An important application of organic halide measurements is in unit process design, control, and monitoring. Each potential application, however, must be carefully assessed to determine the usefulness of organic halide measurements.

ISSN:0003-150X    

DOI:10.1002/j.1551-8833.1985.tb05525.x

出版商:Wiley    

年代:1985

数据来源: WILEY

ISSN:0003-150X    

DOI:10.1002/j.1551-8833.1985.tb05524.x

出版商:Wiley    

年代:1985

数据来源: WILEY