Reactions between chlorine and industrial organic chemicals or precursors in water from natural organic compounds form what?
Trihalomethanes
How does water temperature and pH affect the rate of THM formation?
Higher water temperature and higher pH increases the rate of THM formation
What chemicals can be added to ensure oxidation of neutrally charged arsenic As(III) to a negatively charged As(V) form?
Chlorine or potassium permanganate
What is the MCL for total trihalomethane?
0.080 mg/L
Which THM can be the hardest to remove using PAC?
Chloroform
US EPA approved laboratory methods for analyzing arsenic in drinking water are performed with what instruments?
Mass spectrometry and atomic adsorption
With most all the arsenic removal treatment methods available, what is a common problem they share?
Waste product disposal
Which method of chloramination could produce taste and odors in the water?
Pre-ammonation
What are the three methods of removing THMs after they have formed?
Aeration, oxidation, adsorption
Samples for TTHMs must be analyzed within how many days by the laboratory?
14 days
What is the process called where ammonia is biologically converted to nitrite and nitrate?
Nitrification
Why must air bubbles be prevented from samples collected for TTHMs?
The trapped air allows TTHMs to be released from the water
What can be used in an adsorption process to remove arsenic from drinking water?
Activated alumina
There are the three options available to control THM formation: Remove THMs after they have formed, use a disinfectant other than chlorine and what other option?
Remove THM precursors before chlorine is added
What is the MCL for arsenic?
0.010 mg/L
Why is aeration not effective at removing THM precursors?
THM precursors are not volatile