Page 41 - DPR Rishikesh Legacy_Neat

- Excavator

- Deodorizers
- Bio-culture

- Vehicles

- Conveyor belt
- Hopper

- Rotating Trommels

- Magnetic separator
- Density classifier

- Shredder and Baler

- Front end loader or front end and back hoe loader
4.2.2 EXCAVATION

This excavation is similar to the open mining and involves equipments excavator,
front end loader or backhoe loader or combination of these, as per the requirement of
the site.
The old waste dump contains leachate at different layers and various gases and odor-
causing substances. Before starting excavation, it is necessary to vent out the gases
and drain out the leachate. Ventilation systems for application to such situations have
been developed. Basically, it comprises blowing or sucking air from designated areas
for 2 days before breaking open the dump for excavation. The exhaust air is passed
through filters (preferably bio-filter) to tap the harmful gases. Excavation of waste
material from the dump is then initiated.

During excavation, deodorization spray may require to avoid foul smell along with bio-
culture as per requirement to accelerate the decomposition of degradable material in
the waste.

A frontend loader then organizes the excavated materials into manageable stockpiles
and separates oversized or bulky material. Excavated material either may be directly
processed on-site or be stockpiled for later processing, either on-site or at a
processing facility.

4.2.3 SCREENING

Waste screening begins with the segregation of excavated material into discrete
streams. An electromagnet is used to segregate ferrous material from the main
stream of waste. The nonferrous fraction is processed through an air classifier that
separates light materials from heavy organics. A trommel or vibrating screen
separates soil from solid waste. Trommel screens are more effective than vibrating
screens. The sizes and types of screens used depend on the end use of the
recovered material. For example, if the reclaimed soil is used as landfill cover, a 50

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