Studied by 0 people
Looks like no one added any tags here yet for you.
alkalinity
The capacity of water to neutralize acids. This is caused by (carbonates, bicarbonates, hydroxides), borate, silicate and phosphate
Apparent color
color of the water that includes not only the color due to substances n the water, but also suspended matter aswell.
True color
Color of the water from which turbidity has been removed by filtering
Coagulation
The clumping together of very fine particles into larger particles (floc) caused by the use of chemicals.
complete treatment
A method of treating water that consists of the addition of coagulant chemicals, flash mixing, coag/flocc, sedimentation and filtration. Also called convention treatment.
Direct filtration
A method of treating water which consists of the addition of coagulant chemicals, flash mixing, coag, minimal flocc and filtration.
composite sample
a collection of samples taken at regular intervals over a 24 hour span. they are combined to form one sample that is representative of the average conditions during the sample period.
Grab sample
single sample of water collected at a particular time and place which represents the composition of the water at that particular place and time.
Representative sample
sample of water that is nearly identical in content and consistency as possible to that in the larger body of water being sampled. entire body
disinfection by products DBP
A contaminant formed by the reaction of disinfection chemicals with other substances in the water being disinfected. TTHM or HSA5
Floc
clumps of bacteria and particulate impurities that have come together to form a cluster
Flocculation
The gathering together of fine particles after coagulation to form larger particles by a process of gentle mixing
Jar test
A laboratory procedure that simulates a water plant’s coag/flocc units with differing chemical does to determine the optimum coagulant does. alum pomer
Specific gravity
the weight of a particle, substance, or solution in relation to the weight of an equal volume of water. Water has a specific gravity of one at four degree Celsius
Coag chem basics
Colloids in surface water are - charged, they cant flocculate unless charge is neutralized, positive ions (Alum- coagulant0 are added to neutralize the - ions, once neutralized floc begins to form, polymer can be used to aid floc formation n then the floc is settled (in convention) or filtered out (in direct filtration) of the water. something to not is coag dont work *well when alkalinity is more than 40 mg/L.
Coagulation chemicals
Aluminum sulfate (alum) primary coagulant 14 H molecules, Ferrous Sulfate 7 primary coag n 7 water molecules, Ferric sulfate primary coag n 9 water molecules, Ferric chloride primary coag with 6 water molecules. -=+ polymer coag aid
types of flash mixing (less than a minute)
Hydraulic, mechanical, diffuser n pumped blender
Hydraulic mixers
has baffles
Mechanical mixers
either paddles, turbines, propeller to cause turbulence.
Diffuser mixer
pipes with small holes or opening
Pumped blender mixer
its just pumped out
Streaming current meter
measures electrical charge of water (most particles in water are - charged) n most plants run slightly negative. Zeta potential the difference between a particle’s charge and the water surrounding it.
Enhanced coagulation
Designed to maximize organic matter removal and reduce DBP precursors and its accomplished by reducing pH to optimum coagulation range (alum ideal pH of 5.5-7) ((Ferric sulfate of 4-6.2 not a good choice ))
Why lowering pH works
Humic and Fluvic molecules stay together at lower pH 2. Coagulant demand goes down as humic/fulvic compounds stay together 3. Flocculation is improved as molecules stay together 4. Acids addition pre conditions organic compounds.
Jar testing
used to optimize coagulant dose, determines optimum pH n how much acid to add n if alkalinity addition is necessary.
Change in source water
(pH, turbidity, alkalinity, temp and color) Operator actions are to determine extent of change, evaluate process performance, perform jar test if required, make appropriate process change, increase monitoring frequency n verify plant response to change. Potential process change change coagulant, change dose, adjust flash mix intensity, add coagulant or filter aids, adjust alkalinity or pH.
Change in coagulation process results
(pH, turbidity, alkalinity) Operator actions are to determine Evaluate source water quality, perform jar test if required, verify equipment performance, make appropriate changes n verify plant response. Potential process change coagulant, adjust coagulant dose, adjust flash mix intensity and adjust alkalinity or pH
Change in floc formation
Operator action are to evaluate floc in basin for size n strength, evauate
