Investigating Peroxymonosulfate-UV Advanced Oxidation Process Efficiency for Treated Municipal Wastewater Disinfection and Effluent Quality Recovery

Document Type : Research Paper


Department of Water, Wastewater and Environmental Engineering, Faculty of Civil, Water and Environmental Engineering, Shahid Beheshti University, Tehran, Iran


Eliminating or deactivating the microbial pathogens in wastewater treatment plants effluent has been of particular interest to experts in order to reach the standard quality required. In the meantime, it seems obvious – due to a lack of water resources – that reusing the treated wastewater is a necessity, along with employing and developing modern, efficient solutions. In this regard, the disinfected effluent of wastewater treatment plants has raised interest in various applications containing agriculture, green space irrigation, aquifer feeding, industry, and other municipal activities. In the recent couple of decades, it can be seen that an ever-increasing attention has been paid to the use of ultraviolet (UV) radiation as an efficient method in wastewater treatment plants. However, the results of investigations and existing experiences indicate the negative impact of parameters such as turbidity, hardness, and suspended solids in wastewater on account of the diffusion of radiant energy, as well as obstructing the influence of direct radiation on microorganisms and, in turn, the performance of the UV radiation method in a disinfection process; thus, the application of modern, efficient technologies is requisite for the performance improvement of this process under different operating conditions. Due to their capability of removing toxic, resistant and non-biodegradable compounds, Advanced Oxidation Processes (AOPs) may be adopted as a suitable approach to reach the abovementioned goal. The ultraviolet radiation in conjunction with the effective radicals is considered efficient UV-based AOPs in urban wastewater treatment plants. Not only do these methods lead to reducing the probability of forming toxic and hazardous by-products, they also produce radicals that are highly reactive and react with organic compounds in a non-selective manner. AOPs can eliminate a vast variety of biological and chemical substances, as well as significantly decrease organic and inorganic pollutants by producing highly reactive free radicals, e.g., hydroxyls (OH˚) and sulfate radicals (SO4-˚). Suitable for deactivating microorganisms, these radicals decompose an extensive spectrum of resistant compounds as well. Hydroxyl-based advanced oxidation processes (HR-AOPs) have been comprehensively studied. It should be noted that the sulfate radical has higher reactivity and oxidation potential compared to the oxidizing agent of the hydroxyl radical. As a substitute for HR-AOPs, Sulfate-based Advanced Oxidation Processes (SR-AOPs) have been the focus of many researchers in recent years. This process encompasses the use of chemical oxidants such as Peroxymonosulfate (PMS), which is environmentally friendly and easily activated. The research results in recent years unanimously reveal the high efficiency of AOPs in substantial eliminations of the microbial community within the specimens tested. In the current research, the efficacy of a UV/PMS AOP, which is able to produce both sulfate and hydroxyl radicals, was investigated so as to remove the total amount of coliforms from the effluent of municipal wastewater treatment plants. In order to identify the relative advantages of this method, the obtained results were compared to those of persulfate-UV, hydrogen peroxide-UV, and UV alone methods. In addition, the effect of removing the parameters related to the quality characteristics of wastewater treatment plant’s effluent, comprising turbidity, chemical oxygen demand (COD), biochemical oxygen demand (BOD5), total nitrogen (TN), electrical conductivity (EC), total dissolved solids (TDS) and total suspended solids (TSS), was investigated under optimal operating conditions of laboratory reactors.
Materials and Methods
In this work, the treated wastewater effluent samples were collected daily near the endpoint before chlorination from an activated sludge municipal WWTP located in northeast Tehran. All the experiments were performed by a 250-cc cylindrical reactor and a UV-C lamp model UV-6W. To measure the effluent's quality parameter, we used methods from the standard methods for the examination of wastewater.
Discussion of Results
In this section, the processes of UV/PMS, UV/PS, UV/H2O2, and UV alone have been investigated on the removal of the total coliform, the results achieved as Figures 1 to 3. It was determined that increasing the production of hydroxyl and sulfate radicals during the experiments leads to an increase in the removal of total coliform. We have evaluated the optimum operational conditions for each process. In this way, 400 MPN in 100 ml was considered the allowable limit for the total coliforms to successfully disinfection according to the wastewater reuse standards for agriculture purposes. Regarding the importance of reducing the qualitative parameters of effluent, in this study, the most important parameters such as COD, BOD5, TSS, TDS, TN, TP, EC, and turbidity have been studied under optimum operational conditions of each disinfection method.
In comparison, the UV-radiation alone showed the limited capability to achieve coliforms reduction requirements. As shown in Figure 1, the hydroxyl and sulfate radicals are both produced. The highest removal efficiency is by a PMS dosage of 0.09 mmol/L in a reaction time of 30 min. It should be noted, that the optimum operational conditions for the reactor to achieve the allowable limit of maximum 400 coliforms in 100 ml in a PMS dosage of 0.06 mmol/L, can be obtained by achieving log (MPN) = 2.45 (e.g., 285 MPN/100ml) in a reaction time of 20 minutes, whereas in UV/PS and UV/H2O2 the optimum operating conditions were in the dosage of 3 and 0.35 mmol/L at the time of 30 and 25 minutes, respectively. Therefore, The UV/PMS process showed the best capability to achieve coliforms reduction requirements and efficient disinfection of wastewater treatment plants effluent.
As the results are shown in Table 1, the UV/PMS is the most efficient method to earn the best reduction of effluents' quality parameters. In comparison between these four processes under the optimum operational conditions, these results are achievable that the UV/PMS process had a considerable amount in the removal of turbidity and TSS. Also, it showed an appropriate efficiency in other parameters like COD and BOD5. But this method is still incapable of removing existing TN and TP concentrations.
Wastewater treatment processes with the aim of reuse and reclamation have been investigated and improved during the last decades. Also, efficient disinfection of wastewater effluent before discharge is counted as the essential requirement of reuse. In this regard, employing novel disinfection processes is vital and followed by researchers. In this study, a new approach for improving the UV-based disinfection process for wastewater effluent was investigated. The peroxymonosulfate-ultraviolet was considered as the primary method, and because the obtained results indicate the capability of this method, it was compared with persulfate-ultraviolet, hydrogen peroxide-ultraviolet and conventional UV-radiation methods. In terms of disinfection process improvement, the results demonstrate that employing the peroxymonosulfate-ultraviolet process is suitable for achieving a more reliable solution accordingly. It was also found that this method has the ability to effectively reduce the effluent's quality parameters, in addition to disinfection. It should be noted that using the peroxymonosulfate-ultraviolet method in wastewater treatment plants requires complementary studies regarding possible by-products of the process in a semi-industrial scale which are recommended to be considered in future research.


APHA. (1992). APHA Method 9221: Standard Methods for the Examination of Water and Wastewater. Standard methods for examination of water and wastewaters (20th edition). U.S. Environmental Protection Agency, Washington D.C.
Brahmi, M., Belhadi, N.H., Hamdi, H., Hassen, A. (2010). Modeling of secondary treated wastewater disinfection by UV irradiation: Effects of suspended solids content. Journal of Environmental Sciences, 22, 1218–1224.
Christensen, J., Linden, K.G. (2003). How particles affect UV light in the UV disinfection of unfiltered drinking water. American Water Works Association, Journal AWWA. 95, 179–189.
EPA. (2016). Clean Watersheds Needs Survey 2012. CWNS
Mateo-sagasta, J., Raschid-sally, L., Thebo, A. (2015). Global Wastewater and Sludge Production ,Treatment and Use. Springer, Dordrecht.
Gao, Y. qiong, Gao, N. yun, Deng, Y., Yang, Y. qiong, Ma, Y. (2012). Ultraviolet (UV) light-activated persulfate oxidation of sulfamethazine in water. Chemical Engineering Journal, 195–196, 248–253.
Gholikandi, G.B., Nili Ardakani, M., Moradi, F. (2018). Fered-Fenton technology for efficient waste-activated sludge stabilization: Determination of the main specifications and optimization of the energy consumption. Journal of Environmental Chemical Engineering, 6, 1546–1557.
Gholikandi, G.B., Rasouli Sadabad, H., Karami, S., Masihi, H. (2017). Heavy metal ions removal from waste-activated sludge by Fered-Fenton electrochemical advanced oxidation process (EAOP) with the aim of agricultural land application. Desalination and Water Treatment, 93, 250–256.
Gholikandi, G.B., Zakizadeh, N., Karami, S., Masihi, H. (2017)b. Employing Fered-Fenton advanced oxidation process for waste-activated sludge stabilization and reuse. Desalination and Water Treatment. 93, 267–273.
Gholikandi, G.B., Masihi, H., Azimipour, M., Abrishami, A., Mirabi, M. (2014). Optimizing stabilization of waste-activated sludge using Fered-Fenton process and artificial neural network modeling (KSOFM, MLP). Environmental Science and Pollution Research, 21, 7177–7186.
Gholikandi, G.B., Kazemirad, K. (2018). Application of electrochemical peroxidation (ECP) process for waste-activated sludge stabilization and system optimization using response surface methodology (RSM). Water Science & Technology, 77, 1765–1776.
Giannakis, S., Androulaki, B., Comninellis, C., Pulgarin, C. (2018). Wastewater and urine treatment by UVC-based Advanced Oxidation Processes : implications from the interactions of bacteria , viruses , and chemical contaminants. Chemical Engineering Journal, 343, 270–282.
Hou, L., Li, X., Yang, Q., Chen, F., Wang, S., Ma, Y., Wu, Y., Zhu, X., Huang, X., Wang, D. (2019). Heterogeneous activation of peroxymonosulfate using Mn-Fe layered double hydroxide: Performance and mechanism for organic pollutant degradation. Science of the Total Environment, 663, 453–464.
Lima, J.A., Tonetti, A.L., Vidal, C., Montagner, C.C., Pupo, R.F. (2018). Simultaneous degradation of ciprofloxacin, amoxicillin , sulfathiazole and sulfamethazine , and disinfection of hospital effluent after biological treatment via photo-Fenton process under ultraviolet germicidal irradiation. Applied Catalysis B: Environmental, 224, 761–771.
Liu, L., Hall, G., Champagne, P. (2018). Disinfection Processes and Mechanisms in Wastewater Stabilization Ponds : A Review. Environmental Reviews, 26, 417–429.
Luo, Y., Guo, W., Hao, H., Duc, L., Ibney, F., Zhang, J., Liang, S., Wang, X.C. (2014). A review on the occurrence of micropollutants in the aquatic environment and their fate and removal during wastewater treatment. Science of the Total Environment, 473–474, 619–641.
Malvestiti, J.A., Dantas, R.F. (2017). Disinfection of secondary effluents by O3, O3/H2O2 and UV/H2O2: Influence of carbonate, nitrate, industrial contaminants and regrowth. Journal of Environmental Chemical Engineering. 6, 560–567.
Malvestiti, J.A., Dantas, R.F. (2019). Influence of industrial contamination in municipal secondary effluent disinfection by UV/H2O2. Environmental Science and Pollution Research, 26, 13286–13298.
Masihi, H., Gholikandi, G.B. (2018). Employing Electrochemical-Fenton process for conditioning and dewatering of anaerobically digested sludge: A novel approach. Water Research, 144, 373–382.
Miklos, D.B., Hartl, R., Michel, P., Linden, K.G., Drewes, J.E. (2018). UV/H2O2 process stability and pilot-scale validation for trace organic chemical removal from wastewater treatment plant effluents. Water Research, 136, 169-179.
Miklos, D.B., Remy, C., Jekel, M., Linden, K.G., Drewes, J.E. (2018)b. Evaluation of advanced oxidation processes for water and wastewater treatment – A critical review. Water Research, 139, 118–131.
Moussavi, G., Fathi, E., Moradi, M. (2019). Advanced disinfecting and post-treating the biologically treated hospital wastewater in the UVC/H2O2 and VUV/H2O2 processes: performance comparison and detoxification efficiency. Process Safety and Environmental Protection, 126, 259–268.
Munter, R. (2001). Advanced Oxidation Processes-Current Status and Prospects. 50, 59–80. Proceedings of the Estonian Academy of Sciences, Chemistry
Nihemaiti, M., Miklos, D.B., Hübner, U., Linden, K.G., Drewes, J.E., Croué, J.-P. (2018). Removal of trace organic chemicals in wastewater effluent by UV/H2O2 and UV/PDS. Water Research, 145, 487–497.
Osińska, A., Korzeniewska, E., Harnisz, M., & Niestępski, S. (2017, May 25). Impact of type of wastewater treatment process on the antibiotic resistance of bacterial populations. 9th Conference on Interdisciplinary Problems in Environmental Protection and Engineering EKO-DOK, Poland.
Paredes, L., Omil, F., Lema, J.M., Carballa, M. (2018). What happens with organic micropollutants during UV disinfection in WWTPs? A global perspective from laboratory to full-scale. Journal of Hazardous Materials, 342, 670–678.
Petrie, B., Barden, R., Kasprzyk-hordern, B. (2014). A review on emerging contaminants in wastewaters and the environment : Current knowledge , understudied areas and recommendations for future monitoring. Water Research. 72, 3–27.
Ramezani, M., Noori, R., Hooshyaripor, F., Deng, Z. (2019): Numerical modelling-based comparison of longitudinal dispersion coefficient formulas for solute transport in rivers. Hydrological Sciences Journal, 64(7), 808–819.
Rizzo, L., Agovino, T., Nahim-granados, S., Castro-alférez, M., Fernández-ibáñez, P., Polo-lópez, M.I. (2018). Tertiary treatment of urban wastewater by solar and UV-C driven advanced oxidation with peracetic acid: Effect on contaminants of emerging concern and antibiotic resistance. Water Research, 149, 272–281.
Rodríguez-chueca, J., Amor, C., Silva, T., Dionysiou, D.D., Li, G., Lucas, M.S., Peres, J.A. (2016). Treatment of winery wastewater by sulphate radicals : HSO5-/ transition metal / UV-A LEDs. Chemical Engineering Journal, 310, 473–483.
Rodríguez-chueca, Fernandes, R., Lucas, M.S., Silva, T., Peres, A., Sampaio, A. (2017). Inactivation of pathogenic microorganisms in freshwater using HSO5-/UV-A LED and HSO5-/Mn+/UV-A LED oxidation processes. Water Research, 123, 113–123.
Rodríguez-chueca, Fernandes, R., Lucas, M.S., Silva, T., Peres, A., Sampaio, A. (2017)b. Inactivation of pathogenic microorganisms in freshwater using HSO5-/UV-A LED and HSO5-/Mn+/ UV-A LED oxidation processes. Water Research, 123, 113–123.
Rodríguez-chueca, J., Laski, E., García-cañibano, C., Vidales, M.J.M. De, Encinas, Á. (2018). Science of the Total Environment Micropollutants removal by full-scale UV-C/sulfate radical based Advanced Oxidation Processes. Science of the Total Environment, 630, 1216–1225.
Sadabad, H.R., Gholikandi, G.B. (2018). Simultaneous effective sludge stabilization and direct electricity generation by merging microbial fuel cell (MFC) and Fered-Fenton reactor: An experimental study. Biomass and Bioenergy, 119, 75–89.
Ulliman, Miklosb, D.B., Hübnerb, U., Drewesb, J.E., Linden, K.G. (2018). Improving UV/H2O2 performance following tertiary treatment of municipal wastewater. Environmental Science: Water Research & Technology, 9.
Water Supply. (2002). International report : water and wastewater disinfection – trends , issues and practices. IWA.
Whitby, G.E., Scheible, O.K. (2004). The History of UV and Wastewater. IUVA NEWS. September 2004.
Yang, Z., Su, R., Luo, S., Spinney, R., Cai, M., Xiao, R., Wei, Z. (2017). Comparison of the reactivity of ibuprofen with sulfate and hydroxyl radicals : An experimental and theoretical study. Science of the Total Environment, 590–591, 751–760.
Zhang, Z., Li, B., Li, N., Sardar, M.F., Song, T., Lv, X., Li, H. (2019). Effects of UV disinfection on phenotypes and genotypes of antibiotic-resistant bacteria in secondary effluent from a municipal wastewater treatment plant. Water Research, 157, 546–554.
Zhang, Xiao, Y., Zhong, Y., Lim, T. (2019)b. Comparison of amoxicillin photodegradation in the UV/H2O2 and UV/persulfate systems: Reaction kinetics, degradation pathways, and antibacterial activity. Chemical Engineering Journal, 372, 420–428.