VPE 511: Environment and Environmental Hygiene (2+1)

CLOSE PACKENING

• The simplest form of this method consists of making a compact block of manure of any desired horizontal dimension but, which for ease in its subsequent treatment should not exceed about 150 cm height.
• The site selected must have a hard level surface, and to the block must be firmly pressed down with shovels or other means The following are methods of close packening patton, Barbar, Alnutt and Hutchison trap.

Patton's method

• Patton's is the simplest form of trap consisting merely of an empervious floor upon which its manure is placed.
• Around the edge of the floor, but quite clear of the packed manure, runs a trench or gutter which has straight and smooth sides and is 10cm deep 15cm wide, into which the third stage larvae of musca fill during their migration.
• The larvae so trapped should be collected daily for destinction.

Baber's method

• It has got four compartments each sufficiently large to hold a week's output of maure. Each compartment is floured with cement concrete slopening document at the edges to a surrounding gutter. Retention of the manure is secured by a enclosure of strong iron posts and wire -netting erected an the floor.
• The manure must be tightly packed into the various compartments in turn and must be moistered if it is too dry and be protected against heavy rainfall by a covering of some sort against heavy rainfall by a covering of some sort.
• Any maggots not killed by the heat of fermentation and leaving the manure to seek a fermentation and leaving its manure to seek a pupation site or trapped in the gutter from which pupation site are trapped in the gutter from which their escape through crawling up the walls can be their escape through crawling up the walls can be prevented by filtering a metal over hang to the edges of the gutter.
• The gutter slope to a sump of appropriate size into which the drainage from the manure is collected. If desired the gutter may be filled with any suitable disinfectant or fly poison.

Allnutt's method

• It have the receptable , killed on three sides and set on a cement concrete or other strong impervious platform and having a gutter running across the open front.
• The surrounding walls and the partition are provided or their inner surface a few can from the top with a baffle or ledge projecting inward in order to prevent migrating larvae which have crawled up the walls from escaping over the edge.
• The manure is stored below the baffle level. The gutter is constructed in front of it and is half with a solution of cresol to kill migrating larvae.
• Here one compartment being filled and tightly packed fermentation and decomposition can proceed in the other which is already full. The system allows the front and top layers of manure to be periodically removed and deposited in the centre of the stack with the least difficulty.

Hutchison's method

• Manure is stored as a platform perforated by may fine slits which stand over a shallow concrete basen sloping slightly to one carrier where there is an outltet pipe and containing water to a depth of 1.5 cm in the shallowest part. Here the maggots leave the manure through the slits of the platform to pupate.
• The water should be drawn off at intervals and the dead and dying maggots destroyed.