In this research, we use the ozonation method for
waste water treatment so we wish the output of the
process in the hospital can be used as drinking water,
because of ozonizer fit to kill bacteria - in the waste.
Beside having a high efficiency, this type of
Wastewater Treatment also can solve the limited land
in the hospital. Ozone is a molecule made of three
oxygen atoms that occurs naturally in the earth and
that can also be manmade. Ozone is used as a
disinfectant for killing microorganisms in the air and
water. Many spas and hot tubs use ozone to keep the
water free of algae and harmful bacteria. Ozone is
also used for industrial and manufacturing purposes,
as well as a bleaching and deodorizing agent. Ozone
was chosen because it is a proven cost-effective
disinfectant that improves the taste of the treated
water and decreases unwanted disinfection by-
products. However, ozone is more effective than
chlorine in disinfecting the water. Ozone disinfection
produces less disinfection by products which will
enable these facilities to meet more stringent drinking
water standards and regulations. Ozone also removes
more trace organic compounds than chlorine which
will result in better tasting and smelling water.
In this research, the data is obtained from one of
the hospitals in Indonesia. there are many
contaminants in wastewater. Contaminants in
wastewater may include physical, chemical, and
biological. The main characteristics of the hospital’s
waste water is the content of coliform bacteria,
because it has very high value. In addition to the high
content of coliform bacteria, the characteristics that is
high of the waste water are BOD, COD, TDS and
TSS. They should be able to done the processing of
the water, but it also can be used as drinking water for
the future. The objectives of this research are:
1. Knowing the characteristics of wastewater in the
hospital.
2. Knowing the results of Wastewater treatment
design of the hospital using ozonation method if it
is appropriate with drinking water standards.
2 BASIC THEORY
Wastewater Treatment Plant (WWTP) is a structure
that is designed to dispose of biological and chemical
waste from the water thus allowing the water to be
reused at other activities. The main purpose of
wastewater treatment is to decompose the content of
pollutants in the water, especially organic
compounds, suspended solids, pathogens and organic
compounds that cannot be decomposed by
microorganisms found in nature. For treating
wastewater parameters, processing units that will be
applied consists of several treatment plant. Based on
the selection it has been done, then in WWTP will be
used unit - of processing unit as follows:
a. Equalisation:
The use of equalization tank aims to generate a
uniform flow so that the processing units in the
installations be able to avoid shock loading. Form of
equalization tank that will be used are rectangular.
During the equalization stirring to prevent the
precipitation of solid and odor. Biological oxidation
due to the agitation in the tank, according to Metcalf
& Eddy (2004), can reduce the concentration of 10-
20% total COD, TDS and TSS by 15-20%.
b. Coagulation and Flocculation:
In the process of coagulation and flocculation, the
water will be very role, because the chemical must be
mixed with water. Stirring / Agitation process will
very quickly and uniform dispersion of compounds in
water, the coagulation process occurs with rapid
stirring. In this case the process of coagulation and
flocculation chemical and physical reactions will
occur precipitation: Aluminium Hydroxide, or ferry
hydroxide. After the formation of deposits caused by
the large floc settles, and this process occurs with
slow stirring. A fast stirrer is very important in the
change of physical factors as well as the efficiency of
coagulant addition, the flocculation is a method for
taking particles and highly dependent on particle size.
c. Sedimentation:
Particles that are in the water may be eliminated in the
sedimentation vessel (Clarifier). In the sedimentation
tank types horizontal removed particles is dependent
upon over flow rate (Vo), in this type there are several
assumptions:
1. Particles and velocity vectors are distributed on a
cross-section of the tank, as a function of the inlet
zone.
2. Transfer the liquid will looking down on the
length of the tank.
3. Particles below will be removed from the tank.
d. Ozonation Process:
Ozone is produced when oxygen (O2) molecules are
dissociated by an energy source into oxygen atoms
and subsequently collide with an oxygen molecule to
form an unstable gas, ozone (O3), which is used to
disinfect wastewater. Most wastewater treatment
plants generate ozone by imposing a high voltage
alternating current (6 to 20 kilovolts) across a
dielectric discharge gap that contains an oxygen-
bearing gas. Ozone is generated onsite because it is
unstable and decomposes to elemental oxygen in a
short amount of time after generation. Ozone is a very