Organic Waste Recycling

Characteristics of organic wastes 53

2.3.6 Fruit and vegetable industry

Processing operations and waste generation

Unit operation
The processing steps for five typical commodities are outlined in Figure 2.10 for
peaches (to exemplify fruits), peas and corn (common vegetables), beets (peeled
root crops), and tomato products (pulped commodities). The principal steps
where water (or steam) is used and where solid and dissolved residuals are
generated are indicated.
The containers of fruits or vegetables are dumped into the first stage washer or
flume or onto belts. The products are conveyed by flumes, pipes, belts, elevators, or
other conveyors between processing steps. Fluming water, generally reused, and
small flows of water to belts, graders, and other equipment for lubrication and
sanitation are not noted in the flow diagrams.

Type of waste generated

Operation Peas Corn

Tomato

products Solid Soluble Soil

Dry dump × ×

Water dump × Ɣ

Air cleaner × × ƔƔƔ

Trash eliminator Ɣ

Husker × Ɣ

Sorting/trimming × × × Ɣ

Washer × × × ƔƔ

Grader/sizer × ƔƔƔ

Cutter × ƔƔ

Peeler/rinse (×) ƔƔ

Blancher/rinse × (×) ƔƔ

Pulper/finisher (×)

Slicer/dicer ƔƔ

Evaporator (×) ƔƔb

aOperational or alternative operations in ().

b Relatively clean water

Figure 2.10 Use of water and generation of wastes in typical unit operations of fruit and
vegetable processing (U.S. EPA 1971)

Water