Aeration
for values ? removal may not be feasible
10 to 100
a volatility of a substance with a factor over ? can easily be removed l.
100
normal air to water ratio at a peak flow in a packed tower aerator
25:1
the minimum air to water ratio at peak flow in a packed tower
25:1
small towers designed to remove relatively volatile compounds may require
5hp
the maximum should be no more than ? in an air to water ratio
80:1
consists of an aeration basin or tank constructed of steal or concrete, equiped with air piping, manifolds, and diffusers.
Diffuser aerators
the relative votality of a substance is expressed as ?
Henry's constant
the process of bringing water and air into close contact to remove or modify consitituents in water
aeration
used to transfer volatile contaminants into the air
aeration
two main aeration methods
air into water and water into air
removal of organic compounds, odorous substances, carbon dioxide and radon
air stripping or desorption
how can the packing be cleaned ?
backwashing
can be used to oxidize iron and partially reduced dissolved gases occuring in splash areas
cascade aerator
type of aerator occurs in splash areas and can be used to oxidize iron and partially reduced dissolved gases
cascade aerator
5 components to a ring tyoe cascade aerator
central feed pipe, overflow baffle, spray bottle, outlet, inlet, aluminum
two types of blowers
centrifugal and positive displacement
air flow is provided by a
centrifugal blower driven by an electric motor
used to oxidize iron, although their primary use is to reduce dissolved gasses and are similar to ring type cascade aerators
cone aerator
removes moisture from the air as it leaves to prevent objectional clouds of moisture coming from the column
demister
in general, spray aeration is sucessful in oxidizing iron or manganese and is very sucessful in increasing what characteristic of water ?
diffused oxygen level
type of aeration used primarily to uncrease the DO content in order to prevent taste and odors ?
diffuser aerator
when injecting oxygen into the water it will increase
dissolved oxygen
much more efficient for dissolved gas removal and for oxidizing iron and manganese
draft aerator
type of aerator is much more efficient in removing dissolved gases and for oxidizing iron and manganese
draft aerator
uses an air flow created by a blower
draft aerator
uses a submersible pump equipped with a draft tube (air intake pipe), creates a vacuum at the spinning impellar causes air to enter through the water intake
draft tube aerator
are used to ensure better mixing when aerators are installed in deep aeration bsain
draft tube aerators two
the packing material in a packed tower is reffered to as ?
dumped packing
top mounted blower which pulls an upward flow of air from vents located near the bottom of the tower
induced draft aerator
type of aerator consisting of a propellar like mixing blade mounted on the end of a vertical shaft driven by a motor
mechanical aerator
increasing dissolved oxygen is great way to ? and remove ?
oxidize and remove contaminants
a cylindrical tank containing packing material with water distributed at the top and airflow introduced from the bottom by a blower, commonly reffered to as an air stripper
packed towers
commonly called air strippers, designed for removal of volatile organic chemicals from contaminated waters
packed towers
if their are any questions of how well a contaminant can be removed, what kind of test can be done ?
pilot plant test
type of packing normally used in water treatment for air strippers
plastic
composed of a tower of tiered slats and an external blower that provides continous flow of air
positive draft aerator
two types of draft aerator
positve draft type and induced draft type
aerator in an enclosed tank, primarily used to oxidize iron and manganese for later removal by filtration
pressure aerators
car must be taken in the blower intake to
prevent contaminants from entering
type of aerator commonly used to oxidize iron to a limit extent and to lower the concentration of dissolved gases. Consisting of three to 5 stack trays.
slack and coke tray aerators
a submerged air diffuser is called
sparger
in the slate and coke tray aerator is usually constructed to have sloping sides called ?, which are used to protect the splash from wind loss and freezing
splash aprons
consists of one or more nozzles connected to a pipe manifold. moving on a mainifold under pressure creating a fountain effect.
spray aerator
sometimes located in a decorative setting at the entrance to the water treatment plant
spray aerator
also used for aeration because the structure protects the spray from windblown losses and reduces freezing problems
spray tower (not packed towers)
aerators draw water into the blade of the aerator and throw the water into the air in tiny droplets, so that the water can pick up oxygen
surface aerator
4 types of mechanical aerators
surface, submerged, combination mechanical, and draft tube aerators