Human Excreta is a source of pollution (water, soil), which leads to various diseases like typhoid, diarrhoea, dysentery, amoebiasis, ascariasis, viral hepatitis, etc. etc.
In order to control these diseases, we require Excreta Disposal and Management.
Methods of Excreta (Night soil) Disposal:-
| Unsewered areas | Sewered areas |
| collection & removal of night soil from bucket and pail latrines by human agency | sewage system present |
| latrines | water carriage and sewage treatment |
| service type latrines (conservancy) Pail type latrine Bucket type latrine | primary treatment Screening Grit removal/ sedimentation |
| non-service type/ sanitary latrines | secondary treatment Trickling filter Activated sludge |
| latrines for camps, temprary use Shallow trench latrine Deep trench latrine Pit latrine Bore hole latrine Biogas plant Compositing | other methods Sewage farming Sea outfall Oxidation ponds |
Sanitation Barrier :-
- Construction of barrier to segregate excreta in such a way as to break the disease transmission cycle.
- Principle 6F’s
- Prevention and control of faecal oral disease
- By Construction of sanitary latrines, disposal pits, control of house fly and other hygiene methods
Sanitary Latrine :-
Non-service type of latrine for human excreta Disposal:-
- Tench latrines/ temporary installations=
- Shallow trench :- used during festivals/ fairs
- Deep trench :- used during army camps, disastrous situations
- Bored hole latrine= for famlies, faecal matter covered with earth
- consists of a circular hole of (30-40 × 400-800)cm, auger (special instrument) is required to build, loose soil lined by bamboo; For a family of 5-6 for a year.
- when 50cm reach the hole is closed with earth and new hole is dug
- purification by anaerobic digestion
- Pit latrine= anaerobic putrefaction of night soil in a pit
- Direct pit latrine= absence of water seal
- inprovement of bore hole latrine, pit of 75×300-350 is dug, lined by pottery rings, concrete plate on the top is kept
- First introduced in west bengal in 1949 also called dug well latrine
- VIP latrine :- inbuilt ventilation system
- Indirect pit latrine :-
- RCA (research cum action project, GOI) TYPE= commonly used at home currently
- PAN
- TRAP
- P – Trap for ground lavatory
- S – Trap for 1-2 floor building
- connecting pipe
- supra structure
- PRAI (Project research and action institute, Lucknow) TYPE
- RCA (research cum action project, GOI) TYPE= commonly used at home currently
- Sulabh shauchalaya :- community latrines
- Direct pit latrine= absence of water seal
- Tank latrines= Anaerobic putrefaction of faecal matter in tank
- Septic tank :- water tight masonary tank for household sewage treatment, adequate for use which have water supply but not sewage system
- (1.5-2×1.2)m, retention time 24 hours
- solid settle down in tank to form sludge where as lighter solids rise to form scum, solid goes anaerobic digestion ➡️ methane formed
- liquid passes out of pipe known as effuent, allowed to percolate in sub soil, digestion by bacteria
- Aqua privy :- consists of water tight chamber, size depends upon no. Of users, purification goes on by anaerobic digestion, further treatment like septic tank and sludge should be removed from time by time.
- Septic tank :- water tight masonary tank for household sewage treatment, adequate for use which have water supply but not sewage system
Further details comes under Sewage treatment so, To read about Sewage treatment, CLICK HERE.