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  1. 1. Hannah Briers, Paul J. Sallis, Ali Yuzir, Norhayati Abdullah, S. Chelliapan / International Journal of Engineering Research and Applications (IJERA) ISSN: 2248-9622 Vol. 2, Issue 6, November- December 2012, pp.080-086 Chemical Oxidation Process For The Treatment Of Antibiotic WastewaterHannah 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 toscientific community that pharmaceutical minimise these adversities. This „cradle to grave‟compounds are not treated sufficiently by strategy has resulted in vast amounts of data andcurrent wastewater treatment methods and several proposals for future improvements intherefore trace amounts of such compounds are manufacturing processes and the treatment ofbeing identified in surface water, ground water wastewaters resulting from these processes5. Only aand sewage effluents. Advanced oxidation small minority of these proposals, however, haveprocesses (AOPs) are now being proposed for the actually been put in to practice.specific treatment of industrial wastewaters and The presence of trace concentrations ofwastewaters containing pharmaceutical products. pharmaceuticals in surface water, groundwater andThe AOP treatment for the antibiotic wastewater wastewater has been recorded in recent years withwas researched following an anaerobic digestion. such frequency that it has become a matter of someVarious combinations of AOPs were considered environmental concern 6. Various differentusing ozone (O3), hydrogen peroxide (H2O2), compounds have been found in varyingultra-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 foundevaluate the efficiency of the AOPs. Results in trace concentrations8. Neither the extent of theshowed that the UV/H2O2 and UV/H2O2/O3 AOPs exposure of drugs to the environment nor thewere considered to be most effective for this proportion of subsequent effects is known presently.particular wastewater. A 70% COD removal anda 56% TOC removal were recorded for the Most drugs are designed to be persistentUV/H2O2 processes, a 66% COD removal and a and can therefore affect the biological systems56.6% TOC removal were recorded for the resulting in the easy penetration of bio membranesUV/H2O2/O3 processes. Sulphate concentrations and persistent biodegradation in order to be effectiveincreased during all AOPs due to oxidation of as possible. Environmental engineers are developinghydrogen sulphide (H2S). methods of reducing pharmaceutical concentrations through improved wastewater treatment methodsKey words: Advanced oxidation process, and improvements in the biodegradability ofantibiotic wastewater, chemical oxidation, sulphate pharmaceutical wastewater effluents2. There are various methods that have beenIntroduction proposed to treat wastewater containing Extensive research in to the occurrence and pharmaceutical drug extracts or drinking waterfate of pharmaceuticals in the environment has been supplies that may contain trace quantities of suchcarried out in recent years1. The aim of the majority contaminants9. These methods include membraneof this work is to identify particularly persistent filtration, granular activated carbon (GAC) andsubstances, the quantities they occur in surface various “in series” methods using combinations ofwaters and wastewater effluents and the eventual floatation and filtration. Although these methodslong-term effects they may have in the aquatic have been successful in some cases for someenvironment2-4. To complete this research the long pharmaceuticals, there is great interest in a newand complicated life-cycle of these products had to theory utilising advanced oxidation processesbe fully examined in order to understand the (AOPs) as either a pre-treatment or co-treatment 80 | P a g e
  2. 2. Hannah Briers, Paul J. Sallis, Ali Yuzir, Norhayati Abdullah, S. Chelliapan / International Journal of Engineering Research and Applications (IJERA) ISSN: 2248-9622 Vol. 2, Issue 6, November- December 2012, pp.080-086stage of the wastewater treatment process10. This Results and discussionmethod has not only been highly successful in Ozone/Hydrogen Peroxidereducing contaminant concentrations, it has also COD Removalbeen deemed suitable for treatment of high strength The results show a general pattern ofindustrial wastewaters containing particularly increasing COD removal with increased H2O2 dosepersistent compounds. (Figure 1). T-tests show there is a significant The AOPs use a combination of strong difference between samples with initial and H2O2oxidising agents such as O3, H2O2, UV and Fenton‟s added. It is evident, however, that an optimum dosereagent11. 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 appearalternative 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 ofpharmaceutical 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 showwastewater in order to determine significant effects that there is no significant difference between theof 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-1overall efficiencies of the processes and also were both further examined when considering UVeconomic measures and practical measures for combined AOPs to investigate which concentrationapplying 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 increasetreatment 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 dosesFenton‟s reagent were set-up according to the proves that O3 as an individual AOP is not asfollowing specifications: O3 generator Model BA- efficient as when combined with other oxidants. The023 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 aO3 output was set at 1.6% with flow rate of 1 Lmin-1 maximum (optimal) is met. The overall process ofat 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 effluent anaerobic reactor treating realpharmaceutical wastewater and contains the Figure 1following characteristics: COD, 1931 mgL-1; TOC,148.6 mg.L-1; sulphate, 102.2 mgL-1 and pH, 8.2. TOC ReductionAround 500ml samples of wastewater used in each TOC removal efficiency (Figure 2) steadilyexperimental run and subjected to 3 h reaction increased with increased H2O2 dose and fewperiod. Control sample (time zero) was also inhibitory effects were witnessed as in the case ofexamined. “Free pH‟ used in each case and all COD, the highest removal efficiency being 31.8% atexperiments were repeated 3-fold and average 60 mgL-1 of H2O2. The lower percentage removalvalues taken. may be due to certain resistant organic compounds All chemical analysis was performed which may not be oxidised during TOC analysis andaccording 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 AOPMethod, total organic carbon (TOC) using Standard was 7.6% and it is therefore evident that the additionMethod 5310A and sulphate analysis by Dionex of H2O2 increases efficiency in this case. T-testsDX-100 Ion Chromatograph. Duplicate readings indicate that there is a significant difference betweentaken for each sample and then averaged. Statistical sample means demonstrating that TOC valuesanalysis using standard deviations of the means for decrease with increased H2O2 concentrations.each AOP were calculated to assess any significantdifferences in the data. T-testing carried out on 0 – Figure 260 mgL-1 O3/H2O2 and a 2-sample t-test was used toevaluate any significant difference between 6 - 20 Sulphate AnalysismgL-1 H2O2/UV. 81 | P a g e
  3. 3. Hannah Briers, Paul J. Sallis, Ali Yuzir, Norhayati Abdullah, S. Chelliapan / International Journal of Engineering Research and Applications (IJERA) ISSN: 2248-9622 Vol. 2, Issue 6, November- December 2012, pp.080-086 The wastewater examined had a low efficiency show more clearly the effect UV has onoriginal content of sulphate at 102.2 mgL-1. The TOC reduction. Figure 7 shows that under UV and aodour of the untreated wastewater was particularly H2O2 dose of 6 mgL-1, a 56.0% TOC removal can bestrong. It had undergone anaerobic digestion achieved. This is slightly increased to 56.6% withpreviously and so it was evident that the anaerobic additional O3 treatment. T-tests show a significantmicro-organisms had reduced any sulphate to difference between samples UV/H2O2 6 mgL-1 andsulphide meaning a strong hydrogen sulphide UV/H2O2 20 mgL-1. Once more the TOC removalodour/gaseous emission. The AOP results in an efficiency overall are higher than with only the H2O2increased level of sulphate, with a maximum 45% and O3 combination processes. TOC values of lessincrease at 60 mgL-1. Levels of 159.9 to 184.5 mgL-1 than 70 mgL-1 are recorded via O3/H2O2/UVwere 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 optimumconcentrations of H2O2 when combined with O3 (6 Sulphate Analysisand 20 mgL-1), it is possible to investigate the Figure 8 shows that the greatest increaseefficacy of this system and examine whether the (%) in sulphate is produced when UV, H2O2 and O3addition of UV can have a positive effect on COD are combined (with 6 mgL-1 of H2O2); an increase ofand TOC reduction and further investigate sulphate 44% is witnessed. The COD and TOC valuesincrease data. Figure 4 shows the comparative COD indicate that increase levels of oxidation aredata and by calculating the COD removal efficiency achieved by the addition of UV. This is evident byfor each sample and taking the mean, the effect UV comparing the UV-combined AOP sulphate resultshas 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 UVmgL-1 H2O2 produces the greatest COD reduction treatment than O3/H2O2. Interestingly, UV as aoverall at 70% (Figure 5). Second to this is the UV, single treatment does not increase sulphate levels asH2O2 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 8AOP than the higher dose (20 mgL-1). This impliesthat an optimum dose also exists when H2O2 is Fenton’s Reagentcombined with UV. Statistically, no significant Due to time constraints, the Fenton‟sdifference was apparent between the means of reagent reaction was applied to the wastewater andsamples UV/H2O2 6 mgL-1 and UV/H2O2 20 mgL-1. stirred continuously for three hours; ideally longerIt is apparent, however, due to the nature of the data reaction times are required with the end-point of theset that a difference does exist if the small % reaction signified by a distinct colour change15. Thedifferences between all samples investigated are reaction was duplicated for purposes of accuracy. Ataken 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 tomuch 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 AOPof lower than 1000 mgL-1 are required, UV must be achieved a 50% COD removal and the mostapplied 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 isaccelerating the formation of the hydroxyl radicals. therefore slightly better than O3/H2O2 systems forUV/H2O2/O3 is the strongest form of oxidation this particular wastewater. Further research onalthough for this particular wastewater, UV and Fenton‟s reagent would allow for reaction times toH2O2 is sufficient to increase the efficacy of the be further investigated and dose requirementsAOP. The final COD values recorded in this case (FeSO4, H2O2) to be experimented with, in order torange from 580 to 700 mgL-1. Longer contact times find optimal levels. From the above results it can beof the wastewater effluent with UV should allow for concluded that the four most efficient AOPs were asCOD 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, theTotal 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 andover time and the averaged values of TOC removal 82 | P a g e
  4. 4. Hannah Briers, Paul J. Sallis, Ali Yuzir, Norhayati Abdullah, S. Chelliapan / International Journal of Engineering Research and Applications (IJERA) ISSN: 2248-9622 Vol. 2, Issue 6, November- December 2012, pp.080-086H2O2 6 mgL-1 alone. This is shown by an even AOPs the sulphur is converted to sulphates and itdistribution 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 aGeneral discussion sulphate concentration increase of 56 and 56.6%, The COD values overall show the amount respectively. This also explains the reduction inof oxygen consumed in the oxidation of organic and odour due to the mineralization of hydrogenoxidizable inorganic materials in the wastewater. sulphide to sulphate under aerobic/O2 richAlthough 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 ConclusionsAOPs in this case, is only 560 mgL-1. This is still The treatment of the antibiotic wastewaterhigh if AOPs were applied post-anaerobic digestion with various different AOP combinations proved toas the final stage of the wastewater treatment be successful in the removal of COD and TOC. Anprocess. The most efficient system proved to be UV increase in sulphate concentrations was alsocombined with 6 mgL-1 of H2O2. The least efficient witnessed. H2O2 concentrations were experimentedsystem was O3 alone and O3 with 2 mgL-1 of H2O2. with for the O3/H2O2 combined AOP. It was obviousAs mentioned previously, an increase dose of 60 from the COD data that an optimal dose > 60 mgL-1mgL-1 H2O2 exerted an inhibitory effect on the AOP. existed and 6 mgL-1 of H2O2 produced the mostThere is a theory that O3 AOPs alone will be equally efficient COD and TOC removals overall. Althoughas efficient as combined systems. This is due to the O3 is able to produce H2O2 alone by the breakdownhypothesis that O3 can breakdown the organic waste of organic matter, it was concluded that the additionwhich will yield H2O2 and therefore ozonation can of H2O2 artificially to the system greatly acceleratedtake place without the extra addition of H2O2. The the formation of the hydroxyl radicals necessary forresults here show that O3 alone is not as effective the efficacy of the system and allowed shorterwithout 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 AOPmuch slower rate than if H2O2 is added artificially to when combined with the optimum dose of H2O2 (6the system. Overall, the increase in COD removal mgL-1) and O3/H2O2 together. The UV/H2O2 systemindicates an increase in the biodegradability of the proved to be most efficient with a 70% CODantibiotic wastewater but it is evident that either: removal and 56% TOC removal. COD levels oflonger reactions times are required to further remove below 700 mgL-1 were achieved and TOC levels ofCOD or further treatment of the wastewater is below 70 mgL-1 were achieved. Fenton‟s reagentrequired following the AOP to further decrease the proved to have some positive effect on theCOD 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 isproportion of organic material that has been required concerning reaction times and dosingoxidised during the AOP. The largest TOC removal requirements (H2O2 and FeSO4). It was however oneefficiency was reported during the O3/H2O2/UV of the most successful AOPs and avoids the extraAPOs, where a 56.6% removal was recorded. This costs required for generation of UV and O3. CODparticular AOP has been proven to be particularly removals of 54% and TOC removals of 26% wereintense in the treatment of various different recorded.industrial wastewaters. The efficacy of the AOP is Sulphate concentrations increased duringlargely dependent on the type of wastewater being all AOPs. The strong smell of the wastewatertreated. In this case, it is evident, that due to the effluent demonstrated a large concentration ofinitial strength of the wastewater (i.e. high TOC and hydrogen sulphide present after the application ofCOD levels), high strength or highly intense anaerobic digestion. Odour was reducedtreatments are required if TOC levels are to be considerably through advanced oxidation as theremoved to a suitable standard. During treatment hydrogen sulphide was converted to sulphate. Thiswith O3 and low concentrations of H2O2, the TOC was supported by the data recording a considerablecontent of the samples was not reduced by any increase in sulphate concentration for each AOP.significant amount; only 8.1% with O3 and H2O2 2mgL-1. An increase in H2O2 concentration did Acknowledgmentsincrease TOC removal but it wasn‟t until the The authors thank University of Newcastle, UK andintroduction of UV that any significant changes in Universiti Teknologi Malaysia for funding andthe wastewater samples were witnessed. facilitating this project. In the post-anaerobic digestion, sulphur ismainly present as sulphide and sulphites. During 83 | P a g e
  5. 5. Hannah Briers, Paul J. Sallis, Ali Yuzir, Norhayati Abdullah, S. Chelliapan / International Journal of Engineering Research and Applications (IJERA) ISSN: 2248-9622 Vol. 2, Issue 6, November- December 2012, pp.080-086References 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
  6. 6. Hannah Briers, Paul J. Sallis, Ali Yuzir, Norhayati Abdullah, S. Chelliapan / International Journal of Engineering Research and Applications (IJERA) ISSN: 2248-9622 Vol. 2, Issue 6, November- December 2012, pp.080-086 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 ProcessUV UV/Ozone UV/H2O2 6mg/l UV UV/OzoneUV/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
  7. 7. Hannah Briers, Paul J. Sallis, Ali Yuzir, Norhayati Abdullah, S. Chelliapan / International Journal of Engineering Research and Applications (IJERA) ISSN: 2248-9622 Vol. 2, Issue 6, November- December 2012, pp.080-086 100% 80% 60%% Reduction/Increase 40% 20% 0% Ozone/H2O2 UV/H2O2 UV/H2O2 Fentons 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