Organic Waste Recycling

444 Organic waste reuse and recycling: technology and management

slope height and draw a schematic diagram of this OF unit or plots. The

design OF system is based on Equation 8.13.

b) If this municipality is located on a flat plain land, suggest measures to

make the OF site suitable for wastewater treatment and a method to

reuse of the OF effluent that would be both acceptable by the students

and microbiologically safe for them.

8.10 An agro-industry factory in northeast Thailand produces wastewater

with the following characteristics:

Flow rate = 20 m^3 /day

N concentration = 20 g/m^3

a) The factory plans to use its wastewater to grow corns. Determine the

land area of the corn field that can be irrigated by this wastewater so

that the percolate N is equal to or less than 10 mg/L (to prevent

methamoglobinemia).

Note: N uptake of corns = 200 kg/(ha-year)

Denitrification = 20% of applied N loading

Precipitation (PP) – Evapotranspiration (ET) = -20 cm/yr

Runoff = 0

b) If, due to an unusual weather in the year 2004, the Pp-ET is equal to +

20 cm/yr, but the factory still applies all its wastewater to this same

land area of the cornfield. What would be the effects of this practice on

corn growth and groundwater N concentration? Give reasons.