摘要:

Should an emergency strike, system safety and reliability can be increased if utilities have a plan of action.Your utility probably runs like clockwork, the water moving smoothly from process to process before it flows through the distribution system. But would you still be able to operate reliably if a tornado struck or an earthquake hit or an outbreak of waterborne disease erupted? If you don't have an emergency preparedness plan in effect and disaster strikes, your utility will be scrambling to recover. And in hindsight, you will wish you'd had a plan at the ready. Following the step‐bystep process described here can increase the safety of your water supply, even in the event of an emergency.

ISSN:0003-150X    

DOI:10.1002/j.1551-8833.1994.tb06137.x

出版商:Wiley    

年代:1994

数据来源: WILEY

摘要:

Atrazine, which is not readily removed by conventional treatment, may cause problems for water utilities in agricultural areas.To help managers, planners, and regulators determine when and where surface waters are likely to be adversely affected by organonitrogen herbicides, the authors analyzed various data on the distribution of these compounds in the lower Kansas River basin. They found that atrazine was the most frequently detected herbicide, was found in the highest concentrations, and was most likely to exceed the maximum contaminant level. The highest atrazine concentrations in the water were measured where the largest amounts of atrazine had been applied to the land, and median concentrations were higher in spring and summer than in fall and winter. Atrazine and chemically similar herbicides are not effectively removed by traditional water treatment. The Kansas State Board of Agriculture has established a pesticide management area to decrease the amount of atrazine that enters surface water.

ISSN:0003-150X    

DOI:10.1002/j.1551-8833.1994.tb06139.x

出版商:Wiley    

年代:1994

数据来源: WILEY

摘要:

The possible benefits of reduced coagulant demand and head loss resulting from preozonation must be weighed against increased organic matter in the finished water.Prior investigations have identified many of the mechanisms by which natural organic matter (NOM), coagulant, and particles interact in ozonated systems. This study investigated the effects of ozonation on coagulation with cationic polymer and with polymer‐metal salt mixtures. Preozonation decreased the concentration of NOM that reacts with polymer, reducing organic carbon removal, polymer coagulant demand, and the rate of head loss buildup during direct filtration. The effects of ozonation in systems using dual coagulants (alum‐polymer or ferric chloride‐polymer) were a blend of the effects observed for the coagulants individually.

ISSN:0003-150X    

DOI:10.1002/j.1551-8833.1994.tb06140.x

出版商:Wiley    

年代:1994

数据来源: WILEY

摘要:

Speciation of iron is necessary in assessing whether oxidant addition will prove advantageous during treatment.Greater knowledge of the interaction between soluble iron, dissolved organic carbon (DOC), and alternative oxidants is warranted if the latter are to be optimized for iron removal. An important conclusion of the work is that speciation of iron (differentiation of particulate, colloidal, and soluble forms) in source‐ and treated‐water samples is needed to determine whether oxidant addition will prove advantageous. Source waters that contain predominantly particulate or colloidal iron may be effectively treated by coagulation and separation processes alone, whereas removal of soluble iron requires the addition of any one of the oxidants studied: potassium permanganate, chlorine dioxide, or hypochlorous acid. Both the concentration and nature of DOC in water were found to affect the residual iron speciation that followed oxidant addition.

ISSN:0003-150X    

DOI:10.1002/j.1551-8833.1994.tb06141.x

出版商:Wiley    

年代:1994

数据来源: WILEY