Upload
phil-house
View
617
Download
6
Tags:
Embed Size (px)
DESCRIPTION
Phil House
Citation preview
Domestic Septic Tanks
Phil House
Consider
Aerobic Anaerobic Biochemical oxygen demand
(BOD) Effluent Scum Sludge Sewage
Septic Tanks
Primary Treatment• Separation of liquids and solids
• Does not purify sewerage
Septic tanks depend on two kinds of bacteria
Anaerobic – living or occurring without oxygen
Aerobic - organisms & processes that require oxygen
B.O.D
Biochemical Oxygen Demand
The amount of oxygen consumed by chemical process and micro-organisms to break down organic matter in water over a five day period, measure in milligrams per litre (mg/L)
1. 10/10/10 water quality standard indicating an effluent quality of <10mg/L
Biochemical Oxygen Demand <10mg/L suspended solids and <10mg/L E.coil
cfu/100mL.this water quality is the standard required for grey water to be recycled to a
dwelling for toilet flushing and for the use in the washing machine. It may also be used
for surface and sub-surface irrigation.
2. 20/30 water quality standard indicating an effluent quality of 20mg/L Biochemical
Oxygen Demand and 10mg/L suspended solids. This water quality standard is
applicable for surface and sub-surface irrigation.
3. 20/30/10 water quality standard indicating an effluent quality of <20mg/L
Biochemical Oxygen Demand <30mg/L suspended solids and <10mg/L E.coil This
water quality standard is applicable for surface and sub-surface irrigation.
Explained next slide
biochemical oxygen demand . The amount of oxygen required
by aerobic micro-organisms
Suspended solids refers to small solid particles which remain
in suspension in water as a colloid or due to the motion of the
water. It is used as one indicator of water quality.
E. coli (Escherichia coli) is one of several types of bacteria that
normally inhabit the intestine of humans and animals
(commensal organism). Some strains of E. coli are capable of
causing disease under certain conditions when the immune
system is compromised or disease may result from an
environmental exposure.
Reln Plastic Tank