Encyclopedia of Environmental Science and Engineering, Volume I and II

(Ben Green) #1

654 MANAGEMENT OF SOLID WASTE


TABLE 13
Solid waste management methods

Type Present usage Relative cost Items disposed of Principal benefits

Sanitary landfill Most used (80%)
decreasing^9

Lowb All except hazardous
materials

Low initial cost,
takes all items
may reclaim land
Central incineration Increasing
second largest
method (4%)

High All burnable except
special items and
over-sized items

Reduces volume,
clean product can
produce by-
product items
Open burning Illegal Low Construction
wastes, leaves,
agricultural waste
Compaction, high
pressure

Two plants in
operation

Medium-high All except
hazardous
materials

Produces dense,
essentially inert
blocks for fill
Composting Very few Medium-high Organic only.
No tires,
large pieces

Provides soil
conditioner

Garbage grinding Large number home
units

High Organic only Reduces domestic
collections
Dumping Not legal Lowest Non-putrescibles
Recycling Only for selected
materials and
areas, increasing

High Selected.
Depends
on process

Reduces quantity
for ultimate
disposal
a Many landfills are not sanitary but are included in this classification.
b Low under $10/ton; Medium $10 to $30/ton; High $30  ton.

1

2

3

4

5

6

7 8

9

10

12

11

13

1) — feed section

2) — feed chute

3) — grate

4) — furnace

5) — residue hopper
6) — secondary combustion chamber and
downpass flue volume

7) — final burning and settling chamber volume

8) — high-pressure opposed spray curtain

9) — fly-ash sluiceways

10) — sequential cyclone collectors

11) — induced-draft fan

12) — bypass flue

13) — provision for added filters or
precipitators

FIGURE 3 Large incinerator schematic.

beyond the scope of this work and the reader is referred to an
excellent work by Richard C. Corey.^22
Incineration in the past has received a bad reputation
because of poor control of gaseous effluents and sloppy han-
dling of solid and liquid effluents. With proper design and
operation an incinerator can meet or exceed requirements

on all effluent discharges. A modern central incinerator is
a more complex operation than a large commercial steam
boiler. It therefore requires skilled operating, maintenance
and supervisory personnel to ensure efficient operation.
At the present time control of particulate matter in the
effluent gas is the most critical problem in incinerator design

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