Organic Waste Recycling

434 Organic waste reuse and recycling: technology and management

Rapid infiltration process

At Lake George, New York, a rapid filtration system has been in operation since

1933. The soil type is sand. Wastewater that has received secondary treatment
      from trickling filters is spread at a rate of about 76 cm/week in the summer. In
      the winter the application rate is reduced to 18 cm/week because of reduced
      flows (the city's population fluctuates seasonally). Spreading of the wastewater
      is continuous, and when ice forms on the surface it is not removed but merely
      floated by the next wastewater application (Crites and Pound 1976). The
      operating and performance data are shown in Table 8.13.

Table 8.12 Operating and performance data of an irrigation system in San Angelo, Texas
(U.S. EPA 1981)

Annual wastewater loading rate, cm/yr

BOD in applied wastewater, mg/L

BOD in percolate, mg/L

BOD removal, %

Total N in applied wastewater, mg/L as N

Total N in percolate, mg/L as N

N removal, %

290

89

0.7

99

35.4

6.1

83

Table 8.13 Operating and performance data of a rapid infiltration system in Lake George,
New York (U.S. EPA 1981)

Hydraulic loading rate, cm/week

Summer loading rate, cm/week

Winter loading rate, cm/week

BOD:N ratio

Flooding to drying time ratio

Average BOD loading rate, kg/(ha-day)

BOD in applied wastewater, mg/L

BOD in percolate water, mg/L

BOD removal, %

Total N in applied wastewater, mg/L as N

Total N in percolate, mg/L as N

Removal of total N, %

Soluble phosphate in applied wastewater, mg/L as P

Soluble phosphate in percolate, mg/L as P

Removal of soluble phosphate, %

Fecal coliforms in applied wastewater, MPN/100 mL

Fecal coliforms in percolate, MPN/100 mL

58

76

18

2:1

1:4

53

60

1.2

98

11.5 (summer), 12.0 (winter)

7.70 (summer), 7.50 (winter)

33 (summer), 38 (winter)

2.1

< 1 (summer), 0.014 (winter)

> 52 (summer), 99 (winter)

359,000

72 (summer), 0 (winter)