Environmental Engineering Reference
In-Depth Information
TABLE 9.3
Toxicity of Radioac
tive Elements
Degree of Toxicity Radioactive Element
Extremely high
210
Pb,
210
Po,
226
Ra,
228
Th,
232
Th,
232
U,
237
Np,
238
Pu,
239
Pu,
241
Am,
242
Cm
High
90
Sr,
106
Ru,
124
Sb,
126
I,
129
I,
144
Ce,
170
Tm,
210
Bi,
223
Ra,
224
Ra,
227
Th,
234
Th,
230
U,
233
U,
234
U,
235
U,
241
Ru
Medium
22
Na,
24
Na,
32
P,
35
S,
36
Cl,
54
Mn,
56
Mn,
59
Fe,
60
Co,
82
Br,
89
Sr,
90
Y,
91
Y,
95
Nb,
95
Zr,
105
Ru,
125
Sb,
132
I,
133
I,
134
I,
134
Cs,
137
Cs,
141
Ce,
171
Tm,
203
Pb,
206
Bi,
231
Th,
239
Np
Moderate
14
C,
38
Cl,
55
Fe,
64
Cu,
69
Zn,
71
Ge,
97
Zr,
131
Cs,
136
Cs
Low
3
H
Source:
Korolev, V.A.:
Electrochemical Remediation Technologies for Polluted Soils, Sediments and
Groundwater
. 127-135. 2009. Copyright Wiley-VCH Verlag GmbH & Co. KGaA.
• Electrokinetic-bioremediation
• Electrokinetic-phytoremediation
• Electrokinetic-stabilization
• Electrokinetic-thermal treatment
Most of the integrated methods have been tested for the removal of
organic contaminants, but a few of them, especially electrokinetic-PRBs,
electrokinetic-phytoremediation, and electrokinetic-stabilization proved
efficient for the remediation of sites contaminated with heavy metals.
The combined techniques may enhance kinetics of the reactions, elimi-
nate clogging due to mineral precipitation, and increase desorption, thus
improving the long-term performance. Another future-oriented aspect is
the use of nanomaterials. Research into these coupled technologies is at
an early stage and additional work is needed to exploit their potential for
remediation.
9.5 Outlook
Contaminations with radionuclides stem from nuclear weapons test-
ing, nuclear accidents, and the legacy of uranium mining and processing.
Contaminated sites can be found all over the world. Remediation methods
comprise physical, chemical, and biological processes. The limiting factor
for remediation is often not the lack of applicable technologies but economic
reasons (Zhu and Chen 2009). Therefore, the development of environmen-
tally friendly, economical, and efficient remediation processes are the future
challenges for scientists and engineers. There is a need for further research
into the mechanisms of passive physicochemical and biological methods.
Search WWH ::
Custom Search