Page 220 - Environmental Control in Petroleum Engineering

206 Environmental Control in Petroleum Engineering

Table 7-1
Maximum Recommended Heavy
Metal Concentration in Soii
Element Soil Concentration (mg/kg)
Arsenic 300
Boron 3 *
**
Barium
Beryllium 50
Cadmium 3
Cobalt 200
Chromium 1,000
Copper 250
Mercury 10
Manganese 1,000
Molybdenum 5
Nickel 100
Lead 1,000
Selenium 5
Vanadium 500
Zinc 500
*Concentration in soil-paste extract.
**Depending on site conditions, can be as high as 100,000 mg/kg.
Source: Anderson et al., 1983.
Copyright Butterworth-Heinemann Publishers, 1983, with permission.

of the waste solids. This additional processing may include adding
fertilizers and tilling repeatedly to increase oxygen uptake in the soil.
Most farmers do not object to landspreading because it provides
some irrigation, helps condition the soil, stabilizes wind erosion,
improves soil structure, and can improve crop yield (American Petrol-
eum Institute, 1983; Deuel, 1990; Zimmerman and Robert, 1990).
There are two significant problems with land treatment that may
limit future applications. First, land treatment provides little control
over where mobile (leachable) fractions of the waste will go. Second,
the spreading of oily wastes results in emissions of volatile organic
compounds. These problems may result in a treatment project to be
in violation of some applicable laws and regulations governing air
pollution. This has led to land treatment being banned in some areas.