Civil Engineering Reference
In-Depth Information
TABLE 23-23. EPA Guidelines for Radium and Uranium Disposal
Sludge Concentration
Disposal
3 pCi / g of radium and
50 g / g of uranium
Can mix and spread dewatered sludges
with other municipal refuse in a
municipal landfill. Sludges should
be
10% of volume going into
landfill.
3 to 50 pCi / g of radium
Use physical barrier (earthen cover) to
prevent radon release; avoid
inappropriate use of site.
50 to 2,000 pCi / g of radium
Consider RCRA permitted hazardous
waste sites.
50 to 500 g / g of uranium
Consider disposal at licensed lowland
radioactive waste facility or
recovery of the uranium.
2,000 pCi / g of radium or
500 g / g of uranium
Use low-level radioactive waste
facility or other facility with permit
for NORM waste disposal.
MEMBRANE CONCENTRATE DISPOSAL
Introduction and Background
Reverse osmosis (RO), electrodialysis (ED) or electrodialysis reversal (EDR), nanof-
iltration (NF), ultrafiltration (UF), and microfiltration (MF) are all membrane processes
that produce residual waste streams or concentrates.
A publication of the U.S. Office of Technology Assessment has ranked the waste
concentrate generation from various membrane processes in terms of percent recovery
of feedwater and percent disposal as waste concentrate (Table 23-24).
Conventional methods employ disposal of concentrates to surface bodies of water;
spray irrigation combined with another dilution stream; deep well injection; drainfields;
boreholes; and wastewater collection systems. More costly, nonconventional methods
include evaporation and crystallization technologies, evaporation by solar ponds, and
solar distillation.
Table 23-25
1
summarizes concerns, constraints, and requirements of conventional
concentrate disposal methods.
TABLE 23-24. Membrane Concentrate Generation
Percent Recovery
of Feedwater
Percent Disposal
as Concentrate
Membrane Process
UF
80-90
10-20
NF
80-95
5-20
Brackish water RO
50-85
15-30
Seatwater RO
20-40
60-80
ED
80-90
10-20
Source:
Reference 1.
