Chemical Oxidation for Treating Antibiotic Wastewater

Hannah Briers, Paul J. Sallis, Ali Yuzir, Norhayati Abdullah, S. Chelliapan / International
Journal of Engineering Research and Applications (IJERA) ISSN: 2248-9622 www.ijera.com
Vol. 2, Issue 6, November- December 2012, pp.080-086
Chemical Oxidation Process For The Treatment Of Antibiotic
Wastewater
Hannah Briers*, Paul J. Sallis*, Ali Yuzir**, Norhayati Abdullah*** and S.
Chelliapan****
*Environmental Engineering Group, School of Civil Engineering and Geosciences, University of Newcastle
upon Tyne, Newcastle upon Tyne NE1 7RU, UK.
**Department of Environmental Engineering, Faculty of Civil Engineering, Universiti Teknologi Malaysia,
81310, Skudai, Malaysia.
***Department of Biotechnology Industry, Faculty of Biosciences and Bioengineering, Universiti Teknologi
Malaysia, 81310, Skudai, Malaysia.
****UTM Razak School of Engineering and Advanced Technology, Universiti Teknologi Malaysia
(International Campus), Jalan Semarak, 54100, Kuala Lumpur, Malaysia.

Abstract
There is growing concern from the magnitude of the effects and propose ideas to
scientific community that pharmaceutical minimise these adversities. This „cradle to grave‟
compounds are not treated sufficiently by strategy has resulted in vast amounts of data and
current wastewater treatment methods and several proposals for future improvements in
therefore trace amounts of such compounds are manufacturing processes and the treatment of
being identified in surface water, ground water wastewaters resulting from these processes5. Only a
and sewage effluents. Advanced oxidation small minority of these proposals, however, have
processes (AOPs) are now being proposed for the actually been put in to practice.
specific treatment of industrial wastewaters and The presence of trace concentrations of
wastewaters containing pharmaceutical products. pharmaceuticals in surface water, groundwater and
The AOP treatment for the antibiotic wastewater wastewater has been recorded in recent years with
was researched following an anaerobic digestion. such frequency that it has become a matter of some
Various combinations of AOPs were considered environmental concern 6. Various different
using ozone (O3), hydrogen peroxide (H2O2), compounds have been found in varying
ultra-violet (UV) and Fenton’s reagent. Chemical concentrations including; antibiotics, beta-blockers,
oxygen demand (COD), total organic carbon anti-ulcer drugs, analgesics and anti-inflammatory7.
(TOC) and sulphate analysis were carried out to Birth control pills and caffeine have also been found
evaluate the efficiency of the AOPs. Results in trace concentrations8. Neither the extent of the
showed that the UV/H2O2 and UV/H2O2/O3 AOPs exposure of drugs to the environment nor the
were considered to be most effective for this proportion of subsequent effects is known presently.
particular wastewater. A 70% COD removal and
a 56% TOC removal were recorded for the Most drugs are designed to be persistent
UV/H2O2 processes, a 66% COD removal and a and can therefore affect the biological systems
56.6% TOC removal were recorded for the resulting in the easy penetration of bio membranes
UV/H2O2/O3 processes. Sulphate concentrations and persistent biodegradation in order to be effective
increased during all AOPs due to oxidation of as possible. Environmental engineers are developing
hydrogen sulphide (H2S). methods of reducing pharmaceutical concentrations
through improved wastewater treatment methods
Key words: Advanced oxidation process, and improvements in the biodegradability of
antibiotic wastewater, chemical oxidation, sulphate pharmaceutical wastewater effluents2.
There are various methods that have been
Introduction proposed to treat wastewater containing
Extensive research in to the occurrence and pharmaceutical drug extracts or drinking water
fate of pharmaceuticals in the environment has been supplies that may contain trace quantities of such
carried out in recent years1. The aim of the majority contaminants9. These methods include membrane
of this work is to identify particularly persistent filtration, granular activated carbon (GAC) and
substances, the quantities they occur in surface various “in series” methods using combinations of
waters and wastewater effluents and the eventual floatation and filtration. Although these methods
long-term effects they may have in the aquatic have been successful in some cases for some
environment2-4. To complete this research the long pharmaceuticals, there is great interest in a new
and complicated life-cycle of these products had to theory utilising advanced oxidation processes
be fully examined in order to understand the (AOPs) as either a pre-treatment or co-treatment

80 | P a g e

stage of the wastewater treatment process10. This Results and discussion
method has not only been highly successful in Ozone/Hydrogen Peroxide
reducing contaminant concentrations, it has also COD Removal
been deemed suitable for treatment of high strength The results show a general pattern of
industrial wastewaters containing particularly increasing COD removal with increased H2O2 dose
persistent compounds. (Figure 1). T-tests show there is a significant
The AOPs use a combination of strong difference between samples with initial and H2O2
oxidising agents such as O3, H2O2, UV and Fenton‟s added. It is evident, however, that an optimum dose
reagent11. When used individually or in combination exists which needs further examination when
(e.g. O3 with H2O2) they can provide an efficient combining H2O2 and O3 with UV. The results appear
alternative for treatment of pharmaceutical to show that at concentrations of 6 and 20 mgL-1,
wastewater 12. This particular study examines percentage reduction of COD is highest at values of
pharmaceutical wastewater from the production of 50% for each. However, the standard deviations,
an antibiotic. Various AOPs were applied to the calculated from the means of these experiment show
wastewater in order to determine significant effects that there is no significant difference between the
of each individual or combined process. The COD removal efficiency for 6 to 20 mgL-1 of H2O2.
evaluation of these processes took in to account Therefore, H2O2 concentrations of 6 and 20 mgL-1
overall efficiencies of the processes and also were both further examined when considering UV
economic measures and practical measures for combined AOPs to investigate which concentration
applying such treatment methods in practice. is most effective; the upper limit or the lower limit.
The aim of this research was to investigate At H2O2 doses of 60 mgL-1 a marked increase
treatment methods for the antibiotic wastewater of 53% is witnessed (not shown on Figure 1)
using (O3), hydrogen peroxide (H2O2), ultra-violet denoting an inhibitory effect. This is caused by the
(UV) and Fenton‟s reagent. H2O2 accumulating in water and acting as a radical
scavenger hence suppressing the removal of COD14.
Material and Methods The increase in removal efficiency between the
The apparatus for O3, UV, H2O2 and initial (zero) H2O2 dose and 2 – 30 mgL-1 doses
Fenton‟s reagent were set-up according to the proves that O3 as an individual AOP is not as
following specifications: O3 generator Model BA- efficient as when combined with other oxidants. The
023 UK, measured using Standard Method 2350E formation of hydroxyl radicals will be greatly
„O3 /Demand Requirement - Semi Batch Method‟, accelerated by the addition of H2O2 until a
O3 output was set at 1.6% with flow rate of 1 Lmin-1 maximum (optimal) is met. The overall process of
at 200V; Fenton‟s reagent: Ferrous Sulphate (FeSO4) radical oxidation is much faster than direct oxidation
– 6% solution, H2O2 – 30 % solution; H2O2: 30% by O3 which has a much lower oxidation potential.
w/v; UV: Pond-Clear UV6 Model UK with 6W The lowest COD value achieved here is 960 mgL-1.
bulb and 254nm. This is still a high value if this AOP is to be
The antibiotic wastewater was taken from considered the final method of treatment.
an effluent anaerobic reactor treating real
pharmaceutical wastewater and contains the Figure 1
following characteristics: COD, 1931 mgL-1; TOC,
148.6 mg.L-1; sulphate, 102.2 mgL-1 and pH, 8.2. TOC Reduction
Around 500ml samples of wastewater used in each TOC removal efficiency (Figure 2) steadily
experimental run and subjected to 3 h reaction increased with increased H2O2 dose and few
period. Control sample (time zero) was also inhibitory effects were witnessed as in the case of
examined. “Free pH‟ used in each case and all COD, the highest removal efficiency being 31.8% at
experiments were repeated 3-fold and average 60 mgL-1 of H2O2. The lower percentage removal
values taken. may be due to certain resistant organic compounds
All chemical analysis was performed which may not be oxidised during TOC analysis and
according to standard methods13: COD using therefore any data recorded is a slight underestimate.
Standard Method 5220C Closed Reflux Titrimetric The TOC removal efficiency for O3 as a single AOP
Method, total organic carbon (TOC) using Standard was 7.6% and it is therefore evident that the addition
Method 5310A and sulphate analysis by Dionex of H2O2 increases efficiency in this case. T-tests
DX-100 Ion Chromatograph. Duplicate readings indicate that there is a significant difference between
taken for each sample and then averaged. Statistical sample means demonstrating that TOC values
analysis using standard deviations of the means for decrease with increased H2O2 concentrations.
each AOP were calculated to assess any significant
differences in the data. T-testing carried out on 0 – Figure 2
60 mgL-1 O3/H2O2 and a 2-sample t-test was used to
evaluate any significant difference between 6 - 20 Sulphate Analysis
mgL-1 H2O2/UV.

81 | P a g e

The wastewater examined had a low efficiency show more clearly the effect UV has on
original content of sulphate at 102.2 mgL-1. The TOC reduction. Figure 7 shows that under UV and a
odour of the untreated wastewater was particularly H2O2 dose of 6 mgL-1, a 56.0% TOC removal can be
strong. It had undergone anaerobic digestion achieved. This is slightly increased to 56.6% with
previously and so it was evident that the anaerobic additional O3 treatment. T-tests show a significant
micro-organisms had reduced any sulphate to difference between samples UV/H2O2 6 mgL-1 and
sulphide meaning a strong hydrogen sulphide UV/H2O2 20 mgL-1. Once more the TOC removal
odour/gaseous emission. The AOP results in an efficiency overall are higher than with only the H2O2
increased level of sulphate, with a maximum 45% and O3 combination processes. TOC values of less
increase at 60 mgL-1. Levels of 159.9 to 184.5 mgL-1 than 70 mgL-1 are recorded via O3/H2O2/UV
were recorded after 3 h contact time (Figure 3). combined AOPs. These levels may be lowered with
longer reaction times with UV and O3.
Figure 3
Figure 6
Ozone/Hydrogen Peroxide/UV Figure 7
Having found two possible optimum
concentrations of H2O2 when combined with O3 (6 Sulphate Analysis
and 20 mgL-1), it is possible to investigate the Figure 8 shows that the greatest increase
efficacy of this system and examine whether the (%) in sulphate is produced when UV, H2O2 and O3
addition of UV can have a positive effect on COD are combined (with 6 mgL-1 of H2O2); an increase of
and TOC reduction and further investigate sulphate 44% is witnessed. The COD and TOC values
increase data. Figure 4 shows the comparative COD indicate that increase levels of oxidation are
data and by calculating the COD removal efficiency achieved by the addition of UV. This is evident by
for each sample and taking the mean, the effect UV comparing the UV-combined AOP sulphate results
has as an AOP can be seen more clearly. with the O3/H2O2 AOP sulphate results where
The results show clearly that UV with 6 slightly higher figures are witnessed under UV
mgL-1 H2O2 produces the greatest COD reduction treatment than O3/H2O2. Interestingly, UV as a
overall at 70% (Figure 5). Second to this is the UV, single treatment does not increase sulphate levels as
H2O2 6 mgL-1 and O3 system at 66%. It is evident significantly as with other AOPs.
from the graph that the lower dose of H2O2 (6 mgL-1)
has a more positive effect on the efficiency of the Figure 8
AOP than the higher dose (20 mgL-1). This implies
that an optimum dose also exists when H2O2 is Fenton’s Reagent
combined with UV. Statistically, no significant Due to time constraints, the Fenton‟s
difference was apparent between the means of reagent reaction was applied to the wastewater and
samples UV/H2O2 6 mgL-1 and UV/H2O2 20 mgL-1. stirred continuously for three hours; ideally longer
It is apparent, however, due to the nature of the data reaction times are required with the end-point of the
set that a difference does exist if the small % reaction signified by a distinct colour change15. The
differences between all samples investigated are reaction was duplicated for purposes of accuracy. A
taken in to account. third experiment could not be undertaken at this
Generally, the COD removal efficiency is stage. Fenton‟s reagent has shown the ability to
much higher with the addition of UV than with reduce COD levels to 890 mgL-1; a 54% decrease.
H2O2 and O3 alone. It is apparent that if COD values The most efficient O3/H2O2 combined AOP
of lower than 1000 mgL-1 are required, UV must be achieved a 50% COD removal and the most
applied to ensure effective COD removal for this efficient UV - combined AOP achieved a 70%
particular wastewater. However, the key is removal. The efficacy of the Fenton‟s system is
accelerating the formation of the hydroxyl radicals. therefore slightly better than O3/H2O2 systems for
UV/H2O2/O3 is the strongest form of oxidation this particular wastewater. Further research on
although for this particular wastewater, UV and Fenton‟s reagent would allow for reaction times to
H2O2 is sufficient to increase the efficacy of the be further investigated and dose requirements
AOP. The final COD values recorded in this case (FeSO4, H2O2) to be experimented with, in order to
range from 580 to 700 mgL-1. Longer contact times find optimal levels. From the above results it can be
of the wastewater effluent with UV should allow for concluded that the four most efficient AOPs were as
COD values to be recorded at <500 mgL-1. follows: O3/H2O2 6 mgL-1, UV/ H2O2 6 mgL-1,
UV/O3/H2O2 6 mgL-1 and Fenton‟s reagent (Table 1).
Figure 4 Figure 9 shows that overall, considering COD
Figure 5 removal, TOC removal and sulphate increase, the
Total Organic Carbon AOP that is deemed to be most efficient is UV, O3
Figure 6 shows the pattern of TOC decrease and H2O2 6 mgL-1, followed closely by UV and
over time and the averaged values of TOC removal

82 | P a g e

H2O2 6 mgL-1 alone. This is shown by an even AOPs the sulphur is converted to sulphates and it
distribution within the bars. was observed an overall increase in sulphate
concentration. The general pattern being; the more
Table 1 powerful the oxidation, the higher the concentration
Figure 9 of sulphate. In this case the most powerful AOPs are
UV/H2O2 and UV/O3/H2O2 which result in a
General discussion sulphate concentration increase of 56 and 56.6%,
The COD values overall show the amount respectively. This also explains the reduction in
of oxygen consumed in the oxidation of organic and odour due to the mineralization of hydrogen
oxidizable inorganic materials in the wastewater. sulphide to sulphate under aerobic/O2 rich
Although large COD removal efficiency were conditions experienced during AOPs.
achieved, the high initial COD value (1931 mgL-1)
means that the lowest COD value achieved via Conclusions
AOPs in this case, is only 560 mgL-1. This is still The treatment of the antibiotic wastewater
high if AOPs were applied post-anaerobic digestion with various different AOP combinations proved to
as the final stage of the wastewater treatment be successful in the removal of COD and TOC. An
process. The most efficient system proved to be UV increase in sulphate concentrations was also
combined with 6 mgL-1 of H2O2. The least efficient witnessed. H2O2 concentrations were experimented
system was O3 alone and O3 with 2 mgL-1 of H2O2. with for the O3/H2O2 combined AOP. It was obvious
As mentioned previously, an increase dose of 60 from the COD data that an optimal dose > 60 mgL-1
mgL-1 H2O2 exerted an inhibitory effect on the AOP. existed and 6 mgL-1 of H2O2 produced the most
There is a theory that O3 AOPs alone will be equally efficient COD and TOC removals overall. Although
as efficient as combined systems. This is due to the O3 is able to produce H2O2 alone by the breakdown
hypothesis that O3 can breakdown the organic waste of organic matter, it was concluded that the addition
which will yield H2O2 and therefore ozonation can of H2O2 artificially to the system greatly accelerated
take place without the extra addition of H2O2. The the formation of the hydroxyl radicals necessary for
results here show that O3 alone is not as effective the efficacy of the system and allowed shorter
without H2O2, for this particular wastewater. It is contact times.
possible that O3 ability to yield its own H2O2 is at a UV proved to be the most effective AOP
much slower rate than if H2O2 is added artificially to when combined with the optimum dose of H2O2 (6
the system. Overall, the increase in COD removal mgL-1) and O3/H2O2 together. The UV/H2O2 system
indicates an increase in the biodegradability of the proved to be most efficient with a 70% COD
antibiotic wastewater but it is evident that either: removal and 56% TOC removal. COD levels of
longer reactions times are required to further remove below 700 mgL-1 were achieved and TOC levels of
COD or further treatment of the wastewater is below 70 mgL-1 were achieved. Fenton‟s reagent
required following the AOP to further decrease the proved to have some positive effect on the
COD levels of the water e.g. flocculation. biodegradability of the antibiotic wastewater
The TOC percentage removals quantify the although it is evident that further experimentation is
proportion of organic material that has been required concerning reaction times and dosing
oxidised during the AOP. The largest TOC removal requirements (H2O2 and FeSO4). It was however one
efficiency was reported during the O3/H2O2/UV of the most successful AOPs and avoids the extra
APOs, where a 56.6% removal was recorded. This costs required for generation of UV and O3. COD
particular AOP has been proven to be particularly removals of 54% and TOC removals of 26% were
intense in the treatment of various different recorded.
industrial wastewaters. The efficacy of the AOP is Sulphate concentrations increased during
largely dependent on the type of wastewater being all AOPs. The strong smell of the wastewater
treated. In this case, it is evident, that due to the effluent demonstrated a large concentration of
initial strength of the wastewater (i.e. high TOC and hydrogen sulphide present after the application of
COD levels), high strength or highly intense anaerobic digestion. Odour was reduced
treatments are required if TOC levels are to be considerably through advanced oxidation as the
removed to a suitable standard. During treatment hydrogen sulphide was converted to sulphate. This
with O3 and low concentrations of H2O2, the TOC was supported by the data recording a considerable
content of the samples was not reduced by any increase in sulphate concentration for each AOP.
significant amount; only 8.1% with O3 and H2O2 2
mgL-1. An increase in H2O2 concentration did Acknowledgments
increase TOC removal but it wasn‟t until the The authors thank University of Newcastle, UK and
introduction of UV that any significant changes in Universiti Teknologi Malaysia for funding and
the wastewater samples were witnessed. facilitating this project.
In the post-anaerobic digestion, sulphur is
mainly present as sulphide and sulphites. During

83 | P a g e

References 16th eds. Washington, D.C., American
1. Parsons P., Advanced oxidation processes Public Health Association, (1985)
for water and wastewater treatment, IWA 14. Balcioğlu I. A. and Őtker M., Treatment of
Publishing, London (2004) pharmaceutical wastewater containing
2. Kűmmerer K., Pharmaceuticals in the antibiotics by o3 and o3/h2o2 processes,
environment-sources, fates, effects and Chemosphere, 50, 85-95 (2003)
risks, Springer Publishing (2001) 15. Panizza M. and Cerisola G., Removal of
3. Lanzky P.L. and Halling-Sorensen B., The organic pollutants from industrial
toxic effect of the antibiotic metronidazole wastewater by electrogenerated fenton‟s
on aquatic organisms, Chemosphere, 35, reagent, Water Research, 35, 3987-3992
2553-2561 (1997) (2001)
4. Kasprzyk-Hordern B., Catalytic ozonation
and methods of enhancing molecular ozone
55
reactions in water treatment, Applied
50
Catalysis B: Environmental, 46, 639-669 45
(2003)

COD % Reduction
40
5. Andreozzi R., Caprio V., Insola A., 35
Marotta R. and Sanchirico R., Advanced 30 COD %
oxidation processes for the treatment of 25 Reduction
mineral oil contaminated wastewaters, 20
15
Water Research, 34, 620-628 (2000)
10
6. Jones O.A.H., Voulvoulis N. and Lester 5
J.N., Aquatic environmental assessment of 0
the top 25 prescription pharmaceuticals, 0 2 4 6 8 10 20 30
Water Research, 36, 5013-5022 (2002) H2O2 Dose (mg/l)
7. Zhu W., Yang Z. and Wang L., Application
of ferrous hydrogen peroxide for the Figure 1: COD reduction for O3 and varied
treatment of DSD-acid manufacturing concentrations of H2O2
process wastewater, Water Research, 35,
2087-2091(2001)
8. Gulyas H., Von Bismarck R. and 35
Hemmerling L., Treatment of industrial 30
wastewaters with ozone/hydrogen peroxide,
TOC % reduction

25
Water Science and Technology, 7, 127-
134 (1995) 20 TOC %
9. Mcardell C.S., Molnar E., Suter M.J.F. and 15 Reduction
Giger W., Occurrence and fate of
10
macrolide antibiotics in wastewater
treatment plants and in the Glatt Valley 5

Watershed, Switzerland, Environmental 0
Science and Technology, 37, 5479-5486 0 2 4 6 8 10 20 30 60
(2003) H2O2 Dose (mg/l)
10. Ternes T.A., Stűber J., Herrmann N.,
Mcdowell D., Ried A., Kampmann M. and Figure 2: TOC reduction for O3 and varied
Teiser B., Ozonation: a tool for removal of doses of H2O2
pharmaceuticals, contrast media and musk
fragrances from wastewater?, Water
Research, 37, 1976-1982 (2003)
11. Arslan-Alaton I. and Dogruel S., Pre-
treatment of penicillin formulation effluent
by advanced oxidation processes, Journal
of Hazardous Materials, (2004)
12. Esplugas S., Gimémez J., Contreras S.,
Pascual E. and Rodriguez M., Comparison
of different advanced oxidation processes
for phenol degradation, Water Research,
36, 1034-1042 (2002)
13. APHA, Standard Methods for
Examination of Water and Wastewater,

84 | P a g e

50 160
UV
45 140
Sulphate Increase

40 120 UV/Ozone

TOC (mg/l)
Sulphate % 100
35
Increase UV/H2O2 6mg/l
80
30
60 UV/H2O2 20mg/l
25
40
20 UV/H2O2 6mg/l
20
2 4 6 8 10 20 30 60 /Ozone
H2O2 Dose (mg/l)
0
0 60 120 180
Figure 3: Sulphate profile for O3 and varied Time (min)
concentrations of H2O2
Figure 6: TOC profile for UV combined AOPs

2500
70
2000
COD (mg/l)

60
1500

1000 TOC Reduction (%) 50

40
500
30
0
0 60 120 180 20
Time (min) 10

0
UV UV/Ozone
Advanced Oxidation Process
UV/H2O2 6mg/l UV/H2O2 20mg/l
UV/H2O2 6mg/l/Ozone UV UV/Ozone UV/H2O2 6mg/l UV/H2O2 20mg/l UV/H2O2 6mg/l /Ozone

Figure 4: COD profile for UV combined AOPs Figure 7: TOC reduction profile for UV combined
AOPs

74%
72% 50
Sulphate Increase (%)
COD Reduction (%)

70% 40
68%
30
66%
64% 20
62%
10
60%
58% 0
Advanced Oxidation Process Advanced Oxidation Process

UV UV/Ozone UV/H2O2 6mg/l UV UV/Ozone
UV/H2O2 20mg/l UV/H2O2 6mg/l/ Ozone UV/ H2O2 6mg/l UV/H2O2 20mg/l
UV/H2O2 6mg/l / Ozone
Figure 5: COD reduction profile for UV combined
AOPs Figure 8: Sulphate profile for UV combined AOPs

85 | P a g e


100%

80%

60%
% Reduction/Increase
40%

20%

0%
Ozone/H2O2 UV/H2O2 UV/H2O2 Fenton's
6mg/l 6mg/l 6mg/l/Ozone Reagent

COD TOC Sulphate

Figure 9: Comparative profile for the four most
effective AOPs

Table 1: Comparative data for four of the most
efficient AOPs

AOP COD TOC Sulphate
Removal Removal Increase
(%) (%) (%)
O3/H2O2 6 50 16.2 41
mgL-1
UV/H2O2 6 70 56 38
mgL-1
UV/O3/H2O2 6 66 56.6 44
mgL-1
Fenton‟s 54 26 43
reagent

86 | P a g e

Chemical Oxidation for Treating Antibiotic Wastewater

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