hospital waste water treatment baffle reactor anaerobic
CATEGORIES
OF BIO MEDICAL WASTE (BMW)
https://www.dpcc.delhigovt.nic.in/bio-medical-waste.html
(Please refer Schedule I , Click here to see the Schedule I)
Category No. 1 Human
Anatomical Waste
Category No. 2 Animal
Waste
Category No. 3
Microbiology & Biotechnology Waste
Category No. 4 Waste
sharps
Category No. 5
Discarded Medicines and Cytotoxic drugs
Category No. 6 Soiled
Waste
Category No. 7 Solid
Waste
Category No. 8 Liquid
Waste
Category No. 9
Incineration Ash
Category No. 10 Chemical
Waste
reatment Of
Bio Medical Waste
Category No.1 Incineration /deep
burial
Category No.2 Incineration /deep
burial
Category No.3
Autoclaving/microwaving/incineration
Category No.4
Disinfection(chemical treatment)/autoclaving/microwaving and
mutilation/shredding.
Category No.5
Incineration/destruction/ and drugs disposal in secured landfills
Category No. 6
Incineration/autoclaving/microwaving
Category No.7 Disinfection by
chemical treatment/autoclaving/ microwaving and
mutilation/
shredding
Category No.8 Disinfection by
chemical treatment & discharge into drains
Category No.9 Disposal in
municipal land fill
Category No.10 Chemical treatment
and discharge into drains for liquids and secured
landfill for solids.
Standards for Liquid Waste
PARAMETERS
|
PERMISSIBLE
LIMITS
|
pH
|
6.5-9.0
|
Suspended
Solids
|
100
mg/L
|
Oil
& Grease
|
10
mg/L
|
BOD
|
30
mg/L
|
COD
|
250
mg/L
|
Bio-assay
Test
|
90%
survival of fish after 96 hours in 100% effluent
|
These limits are applicable to those hospitals
which are either connected with sewers without terminal Sewage Treatment Plant
or not connected to public sewers.
For discharge into public sewers with terminal
facilities , the General Standards as notified under the Environment
(Protection ) Act, 1986, shall be applicable . Click here to see the General Standards(Schedule VI)
Main parameters are given below:
PARAMETERS
|
PERMISSIBLE
LIMITS
|
pH
|
5.5-9.0
|
Suspended
Solids
|
600
mg/L
|
Oil
& Grease
|
10
mg/L
|
BOD
|
350mg/L
|
Bio-assay
Test
|
90%
survival of fish after 96 hours in 100% effluent
|
DPCC has taken decision that Hospital having
50 beds or more shall install Effluent Treatment Plant (ETP) for the treatment
of waste water generated and for recycling of treated effluent for use in
horticulture, air conditioning/ cooling plants and flushing of toilet
etc.
In hospitals that have ETP
facility, the treatment is carried out using special scientific process and
generally involves three stages, primary, secondary, and tertiary levels of
treatment. [14]
Average
water consumption 750 liter / bed / day. Please calculate daily water
consumption from borewell to over head tank using water meter. 80% of total
water in nover head tanks is wasted as waste water. This should be the capacity
of the STP to be installed at the hospital. (See table below)
Capacity
of overhead tank from where water is distributed = A Liter
Number of times Over Head Tanks
Filled up in a day = B Nos
Total water requirement for use
at different points = A x B Liter/day
Quantity of Effluent , liter per
day = 80 % of ( A x B )
Sourcess of waste water
1. Bed in Hospital= Nos @ 500
liter per bed = Liter
2. Employee in Hospital = nos @
40 liter per employee= Liter
3. Hostels- Persons = nos @ 150
liters per person. = Liter
4. Kitchen Meals= nos@ 10 liter
per meal = Liter
So, Total Quantity of discharge:
--------- liter per day
Health
Stream Literature Summary - Issue 46 - June 2007
The
treatment of hospital waste water: an appraisal
Pauwels,
B. and Verstraete, W. (2006) Journal of Water & Health, 4 (4)
405-416.
Primary treatment
Consists of temporarily holding the sewage in a
basin where the settled and floating materials are removed and the remaining
liquid subjected to secondary treatment. Primary treatment usually removes from
30 to 40% of the BOD. After this treatment the BOD and COD levels usually comes
down to 25% of its initial levels.
Secondary treatment
Removes the dissolved and suspended biological
matter and is typically performed by indigenous, water borne microorganisms in
a managed habitat. This treatment uses microbial degradation, aerobic or
anaerobic, to reduce the concentration of the organic compounds. The combined
use of primary and secondary treatment reduces approximately 80 to 90% of the
BOD. In this stage, there is settling down of the suspended solid contents of
the biological waste as thick slurry called sludge, while the treated fluid
undergoes tertiary treatment. Through this process, 95% of the pollutants from
the waste water are removed.
Tertiary treatment
Uses chemicals to remove inorganic compounds and
pathogens. This is the final stage of treatment where the effluent after
secondary treatment first is mixed with sodium hypochlorite and then the
effluent is passed through dual media filter (DMF) and activated carbon filter
(ACF) where sand, anthracite, and activated carbon are used as filtration
media. Finally, the treated water is let into a small well to recharge the
water table. This treated waste water now can be used for gardening, toilets,
and laundry purposes. [15]
Chemical
treatment usually involves the use of 1% sodium hypochlorite solution with a
minimum contact period of 30 min or other standard disinfectants like, 10-14 gm
of bleaching powder in 1 l water, 70% ethanol, 4% formaldehyde, 70% isopropyl
alcohol, 2 5% povidone iodine, or 6% hydrogen peroxide
WASTE WATER FLOW RATES IN DIFFERENT UNITS:
Waste water consist primarily of used water, the water that reaches the
sewer . For different units it is different as shown in the chart .
Source
|
Unit
|
Range l/u/d
|
Typical l/u/d
|
Apartment
|
Person
|
200-340
|
260
|
Hotel resident
|
Resident
|
150-220
|
190
|
Hotel Employee
|
Employee
|
30-50
|
40
|
Individual Home
|
Person
|
190-350
|
280
|
Airport
|
Passenger
|
8-15
|
10
|
Automobile service station
|
Vehicle served
|
150-200
|
200
|
Restaurant
|
Meal
|
8-15
|
10
|
Office
|
Employee
|
30-65
|
55
|
Laundry
|
Machine
|
1800-2600
|
2200
|
Laundry
|
Wash
|
180-200
|
190
|
Hospital medical
|
Bed
Employee
|
500-950
20-60
|
650
40
|
School
|
Student
|
20-65
|
40
|
School boarding
|
Student
|
200-400
|
280
|
For Industries
|
|
80% of water used used in production will
be released as waste water
|
|
Meat processing
|
Mg
|
15-20 cu mtr/ Mg
|
|
Milk Products
|
Mg
|
10-20 cu mtr/Mg
|
|
Bread
|
Mg
|
2-4 cu mt/Mg
|
|
Beer
|
Mg
|
10-16 cu mtr/Mg
|
|
Whisky
|
Mg
|
60-80 cu mtr/Mg
|
|
Paper Pulp
|
Mg
|
250-800 cu mt/ Mg
|
|
Paper
|
Mg
|
120-160 cu mtr/Mg
|
|
Textile Bleaching (Cotton)
|
Mg
|
200-300 cu mtr/Mg
|
|
Textile Dyeing (Cotton)
|
Mg
|
30-60 cu mtr/Mg
|
|
REF : WASTE WATER ENGINEERING : TREATMENT ,
DISPOSAL AND REUSE--- METCALF & EDDY .