Removal of pharmaceuticals from water and wastewater using UV

Report
By: Yaal Lester
School of Mechanical Engineering and the Hydrochemistry
laboratory
Tel Aviv University
Dr Hadas Mamane
Dr Dror Avisar
Tel Aviv University
1
Our objective:
Determine the potential of UV and ozone based advanced
low concentrations such as pharmaceuticals and more.
oxidation processes (AOPs), as complementary treatment,
 Traditional
treatments
do little to break
them
down
for the removal
of pharmaceuticals
from
water
and(World
wastewater
Health
Organization).
 Drinking water and waste water contain toxic chemicals at very
AOP: Chemical oxidation involving the production of the hydroxyl radical (•OH)
Households
Industry
Hospitals
Water Works
WWTP
Agriculture
Rivers
Groundwater
2
UV / H2O2 / O3
O3
UV/O3
UV/H2O2
UV/H2O2
OH•
OH•
UV/H2O2/O3
O3/H2O2
UV/H2O2
OH•
OH•
OH•
Pollutant
3
1. Determine the potential of each AOP process
in deionized water (optimization and comparison).
2. Determine the influence of wastewater on the processes
Lab reactor
O3 out
Pilot system
O3 in
H2O2
Feed
Tank
Membrane bioreactor - MBR
O3 reactor
UV reactor
4

2 OH
 Creates AOP conditions ( H O 
),
thus generally more effective than UV alone
 H2O2 concentration is very important
(scavenging effect H O  OH  HO  H O )
h
2

2
*
2
k 2.7107 M 1S 1

2
2
2
0
1.6
-2
1.2
k (1/min)
Ln (Ct/C0)
Example: Sulfamethoxazole degradation
-4
0 mg/L
5 mg/L
-6
10 mg/L
0.8
0.4
0
-8
0
0
2
4
Time (min)
50
100
150
6
[H2O2] (mg/L)
5
200
 Molecular O3 – selective oxidant
 At high pH (~ > 7) may also produce OH• (O3 + OHO3
OH•)
Ciprofloxacin (CIP) and cyclophosphamide (CPD) ozonation (2 mg/L),
with and w/o t-butanol)
0
HN
N
N
OH•
O
-1
F
O
OH
O
O
P
N
H
Cl
N
Ln C/C0
Ciprofloxacin
-2
OH•
CIP
CPD
-3
CPD + t-butanol
CIP + t-butanol
-4
Cl
Cyclophosphamide
O3
0
5
10
Time (min)
15
20
6
 H2O2 react with O3 to form •OH: 2O3 + H2O2
2•OH + 3O2
 H2O2 reduces dissolved O3
reduce the removal of O3 sensitive pollutants
0
0.4
0.12
(1:2)
CIP 0
CIP 0.2
CPD 0
CPD 0.2
0.1
0
10
20
Time (min)
30
0.03
(1:1)
-3
0
0.06
(1/min)
0.2
CPD
-2
0.09
CPD
k
(1/min)
0.3
CIP
-1
k
Ln (Ct/C0)
CIP
40
Cyclophosphamide (CPD) and Ciprofloxacin
(CIP) Degradation ([O3]0 = 0.5 mg/L)
0
0
5
10
H2O2/O3 ratio (M/M)
15
CPD and CIP rate constants at different
H2O2/O3 molar ratio
7
Main influencing parameters
Effluent organic matter (EfOM)
Light screening, OH• scavenging
Carbonates (HCO3-, CO3-2)
OH• scavenging
8
In water
Pollutant
UV
H2O2
OH•
In effluent
Pollutant
UV
H2O2
OH•
EfOM, carbonates
EfOM
9
In water:
Pollutant
Product
O3
OH•
OH-, H2O2
In effluent:
Pollutant
O3
Product
OH•
H2O2
EfOM
OH•
O3 scavenged
EfOM, Carbonates
OH• scavenged
10
1. Use synthetic wastewater effluent (analyze each constitute)
2. Use “real” wastewater effluent (SHAFDAN)
Synthetic effluent characteristics
Parameter
Results
Conductivity
1315 us/cm
pH
8
UVT
75
TOC
0-8 mg/L
Hardness
220 mg/L
PO4-P
0.7 mg/L
NH4-N
3.1 mg/L
NO3-N
0.3 mg/L
Alk
25 and 200 mg/L
Cl
230 mg/L
NaHCO3
11
[O3] = 5 mg/L
(batch mode)
O3 Out
O3 In
DO3 sensor
[CPD] = 1 mg/L
[TOC] = 0 – 8 mg/L
[Alk.] = 25 and 200 mg/L
Cooling sleeve
12
Alkalinity = 25 mg/L
Alkalinity = 200 mg/L
100%
100%
Alginic acid
Alginic acid
NOM
80%
NOM
80%
Peptone
CPD removal
Peptone
CPD removal
60%
40%
40%
20%
20%
0%
0%
0


60%
2
4
6
TOC (mg/L as C)
8
10
0
2
4
6
TOC (mg/L as C)
8
Peptone
and NOM
significantly
reduced
the removal
of CPD at
high at
TOC
The decrease
in CPD
removal due
to alkalinity
was noticeable
mainly
low TOC
-1).
concentration
their
effect on •OH.
concentrationsthrough
(TOC < 5
mg Lscavenging
13
10
O3 (dose 300 mg/L) with and w/o H2O2
TOC
100%
80%
0 mg H2O2
60%
150 mg H2O2
40%
UV / H2O2
20%
100%
0%
80%
0
60
90
120
Time (min)
60%
TOC
30
40%
UV only
UV+50mgL H2O2
20%
UV+250mgL H2O2
0%
0
3
6
9
12
15
18
Time (min)
14
150
Removal of TOC by O3 and UV based processes –
Cost comparison
Process
TOC (mg/L)
In
Out
TOC
Removal
(%)
UV
7.8
6.5
16
O3
7.4
7.2
3
UV/H2O2
7.5
3.6
52
O3/H2O2
7.4
2.7
64
O3 then
UV/H2O2
9.6
4.3
55
O3/H2O2
then
UV/H2O2
9.8
5.3
46
EEM
(kWh/m3/mgL-1)
UV
O3
Total
9.2
9.2
1.4
1.4
9.5
0.3
9.8
11.1
0.5
11.6
15
To conclude…
 UV and O3 based AOP may present an interesting option
for pharmaceuticals removal in water.
 In general, O3 based processes are more energy-efficient.
 Using AOPs for wastewater treatment, one must consider:
1. EfOM in wastewater highly reduce the processes efficiency.
2. Alkalinity influence the processes only at low TOC
concentrations.
16
17

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