Skip to main content


  • Research article
  • Open Access

Pentachlorophenol removal from aqueous solutions by microwave/persulfate and microwave/H2O2: a comparative kinetic study

  • 1,
  • 1 and
  • 2Email author
Journal of Environmental Health Science and Engineering201412:94

  • Received: 21 November 2013
  • Accepted: 5 May 2014
  • Published:


Pentachlorophenol (PCP) is one of the most fungicides and pesticides used in wood protection. Poisoning from PCP may be happened in dermal absorption, and respiration or ingestion. With regard to health and environmental effects of PCP, many methods were studied for its removal. Microwave assisted other methods are environmental friendly, safety, and economical method, therefore, in this study; a modified domestic microwave assisted hydrogen peroxide (MW/H2O2) and sodium persulfate (MW/SPS) was used for PCP removal from aqueous solutions. PCP removal rate was measured under different factors such as pH, energy intensity, SPS, H2O2 concentration, Tert- butyl alcohol (TBA) and chemical oxygen demand (COD). The concentration changes of PCP were determined using spectrophotometer and HPLC spectra, respectively. The best removal PCP rate obtained in condition of pH of 11, 0.02 mol L−1 of SPS, 0.2 mol L−1 of H2O2 and energy intensity of 600 W. Moreover, COD removals in MW/H2O2 and MW/SPS process were 83% and 94%, respectively, also TBA test decreased 15% and 3% of PCP removal in MW/SPS and MW/H2O2 processes respectively. Experimental results indicated that sulfate radical was stronger than hydroxyl radical and examinations order reaction was in first order. In this study, was cleared that MW/SPS process was more effective than MW/H2O2 process in PCP removal.


  • Microwaves
  • Pentachlorophenol
  • Hydrogen peroxide
  • Sodium persulfate


PCP, one of the phenolic compounds, is widely used in Wood protective industry [1]. Exposure of this compound makes diseases such as aplastic anemia, leukemia, peripheral neuropathy and other problems related to nerve damage (neurotoxicity). This pollutant is a significant contaminant of soil, surface, and groundwater especially around wood preserving facilities [26]. Researchers using a mathematical model calculated that 96.5% of PCP is in soil, 2.5% in water, 1% in air, and less than 1% in suspended sediments and organisms in aquatic environments [6, 7]. Therefore, PCP removal from aqueous solutions is essential. According to previous studies is cleared that conventional treatment methods are ineffective for PCP and other refractory compounds removal, because these methods can only transfer the contaminants from one phase to another producing many environmental problems [8]. Recently researchers have found that microwave (MW) heating in combination with hydrogen peroxide (H2O2) and sodium persulfate (Na2S2O8 or SPS) [9] can mineralize organic compounds successfully and completely [6, 10, 11]. The key effects of these processes is the replacement of hazardous solvents with environmentally benevolent ones [8]. Basic of MW process is the ability of molecules or substances to absorb and transmit MW irradiation [12]. MW irradiation is electromagnetic irradiation in the frequency range of 0.3 to 300 GHz, but laboratory microwave reactors operate at frequency of 2.45 GHz [6, 13, 14]. By breaking oxygen–oxygen bonds of H2O2 and S2O82−, MW commonly are able to dissociate H2O2 and S2O82− into OH0 and SO40 radicals and other radicals which are very powerful oxidizing species [15].

Similar to hydroxyl radicals, sulphate radicals react with organics by electron transfer, hydrogen abstraction, or addition mechanisms [16, 17]. According to results obtained of previous studies, SPS and H2O2 could be a good option for the MW oxidation technique. In this study, due to an environmental-friendly in addition to highly efficient method and low existence of specific work in this condition, analysis of the PCP removal by MW/H2O2 and MW/SPS under various kinds of parameters was performed and in the end, the effectiveness of MW/SPS and MW/H2O2 processes in the PCP removal was compared.

Materials and methods


Sodium salt PCP, which is the sodium salt of PCP (C6Cl5ONa) with 98% purity was used without further purification. The characteristics of the PCP included of boiling point: 309-310C0, mass molar: 288.32 g mol−1. PCP solution was prepared by dissolving PCP in NaOH solution to accelerate its dissolution [6, 18]. Hydrogen peroxide (30% w/w) and the sodium persulfate from Merck, 98% mass molar: 238.1 g mol−1 were used as oxidants.

Experimental methods and measurements

Under atmospheric pressure, all of the experiments were performed and triplicated in modified domestic microwave oven (2450 MHz, M2330 DN, SAMSUNG Co, and output power of 100 to 850 W) (Figure 1). Detail modifications of MW were presented as follows: drilled a hole in the upper oven wall and then attached an aluminum tube of the same diameter to the hole then equipped with cooling system and a glass reactor with 500 mL volume. Then Samples were taken at suitable time intervals (10 min) from the reaction reactor with a 10 mL syringe and pipetted in to glass vials [6, 11]. Besides, a Thermometer GENWAY Medal 2003 was utilized to detect variation of solution temperature during degradation process. The leakage of MW oven is measured at 20 cm distance from the aperture.
Figure 1
Figure 1

Schematic diagram of modified microwave system.

In this study different factors effects such as pH (3, 7, 11), energy intensity (180,450,600 W with optimal temperatures 80, 100, and 105C0 respectively), SPS and H2O2 dose (0.01, 0.02, 0.03, 0.04, 0.05 mol L−1), PCP concentration (100, 200, 300, 400, 500, 750, 1000 mg L−1), effect of Tert-butyl alcohol (TBA ) with 0.04 mol L−1 concentration, and COD (344 mg L−1) were determined. Changes of PCP concentration were detected using spectrophotometer according to (APHA [19]), and HPLC. HPLC (Part Number.WATO54275 with dimension of 4.6 mm × 250 mm and column of symmetry C18-50 μm) method was performed with an acetonitrile/water 60:40 (v/v) as mobile phase at a flow rate of 1 mL min−1 and detection wavelengths of UV was 254 nm [6, 20]. COD was detected using potassium dichromate solution as oxidizer in a strong acid medium, then by titration step using ferrous ammonium sulfate as the reducing agent and Ferroin as the indicator [6, 9].

Results and discussion

Effect of pH on PCP removal

In this study under MW/SPS and pHs of 3,7and 11, PCP removal rate was 48, 56, 67% respectively, but under MW/H2O2, its amount was 42, 53 and 56% respectively (Figure 2). It seems that strong power of MW in ionization of SPS and H2O2 leads to a negligible difference between all pHs effect (Figure 2), therefore more research for pH effect is necessary. However, results shown that alkaline pH could more accelerate PCP degradation in MW/SPS and MW/H2O2 systems. These phenomena under MW/SPS and MW/H2O2 were attributed to the ability of H2O2 and SPS to absorb and transmit microwave irradiation in alkaline pH more a little than other pHs. Subsequently more radicals are produced in this condition [2125].
Figure 2
Figure 2

Effect of pH on PCP removal under MW/SPS and MW/H 2 O 2 systems (PCP = 100 mg L −1 , E = 600W, SPS and H 2 O 2 dose = 0.02 mol L −1 , reaction time = 30 min).

In general and according to experimental conditions following reactions can be performed:

Under MW/SPS:
All pHs : SO 4 0 + H 2 O SO 4 2 + OH 0 + H +
Alkaline pH : SO 4 0 + OH SO 4 2 + OH 0
Under MW/H2O2:
H 2 O 2 + MW 2 OH 0
OH 0 + H 2 O 2 H 2 O + HO 2 0
2 OH 0 H 2 O 2
2 OH 0 H 2 O 2 + O 2
OH 0 O 2 + H +
H 2 O + HO 2 0 + O 2 H 2 O 2 + O 2 + OH

Under MW/SPS, the rate constants for Eqs. (1) and (2) are < 2 × 10−3 and (6.5 ± 1) × 107 M−1S−1 respectively. It is cleared that the reaction rate constant of Eq. (2) is more than Eq. (1). According these equations in all pHs and alkaline pH, both SO40− and OH0 are possibility responsible for degradation of organic contaminants, but previous studies have shown that in pHs of 3–10, amount of hydroxyl radical is more than sulfate radical and in pH > 10.5 amount of sulfate radical is more than hydroxyl [26, 27]. According these results, the difference between our work and previous studies could partly attribute to pH = 11. Results of other studies confirm that organic removal efficiency is more in alkaline pH [15]. In similar to, under MW/H2O2 in alkaline pH, amount of OH0 and other radicals participating in PCP removal is more than other pHs (Eqs (3) to (8)) [6, 11, 28].

Effect of SPS and H2O2 concentrations on PCP removal

From Figure 3 is observed that under MW/SPS with increasing SPS concentration from 0.01 to 0.0 2 mol L−1, PCP removal efficiency was increased (56 to 94%). But with increasing the initial SPS concentration from 0.02 to 0.05 mol L−1 PCP removal rate was decreased from 94 to 49% respectively. Furthermore under MW/H2O2, PCP removal efficiency for 0.01 to 0.05 mol L−1 of H2O2 was 12.5% to 75% respectively. PCP removal (87%) was stabled in doses of 0.2 and 0.3 mol L−1 of H2O2 (data not show). Therefore, optimal doses of SPS and H2O2 were 0.02 and 0.2 mol L−1 respectively. Shih et al. reported that, in extremely high initial concentration, SO40− reacted with persulfate according to the following equation [29].
Figure 3
Figure 3

Effect of oxidant concentration on PCP removal under MW/SPS and MW/H 2 O 2 systems (pH = 11, PCP = 100 mg L −1 , E = 600 W, reaction time = 30 min).

SO 4 0 + S 2 O 8 2 SO 4 2 + S 2 O 8 0
So that an over-dose of persulfate transformed the SO40− to S2O80− reducing the oxidizing power for PCP removal [30, 31]. Also with respect to Eq (10), under high H2O2 concentration in MW/H2O2 system, quenching of OH° radicals is happened to produce HO2° radicals [6, 11, 15].
H 2 O 2 + O H 0 H 2 O + H O 2 0

Therefore, existences of a scavenger of OH° radicals, such as H2O2, have a decreasing effect in the organic compounds removal efficiency [6, 17].

Effect of different energy intensity on PCP removal

The test results shown in Figure 4 indicated that PCP removal efficiency gradually increased by increasing the microwave power from 180 to 600 W. Amount of PCP removal in MW/SPS with energy intensity of 180, 450, and 600 W was 26, 89 and 93%, respectively. In addition, under MW/H2O2 system amount of PCP removal was 20, 80 and 87%, respectively. PCP removal efficiency did not change for higher power (>600 W). Subsequently, the microwave irradiation of 600 W was chosen for further experiments. According to other studies, removal efficiency can only increase to a limited extent [32] and degradation of organic materials is not always increased with increasing microwave power [33, 34]. In this study, amount of Energy consumption in optimal condition (energy power of 600 W and reaction time of 30 min) for both of systems was 0.3 KWh , also other researchers confirm that energy consumption in MW process is very low and economy [35, 36].
Figure 4
Figure 4

Effect of energy intensity on PCP removal under MW/SPS and MW/H 2 O 2 systems (pH = 11, PCP = 100 mg L −1 , SPS and H 2 O 2 dose = 0.02 and 0.2 mol L −1 , reaction time = 30 min).

Effect of radical scavenger on PCP removal

In this study, 0.04 mol L−1 TBA (OH0 scavenger) added to MW/SPS and MW/H2O2. The results shown that the degradation rate of PCP was decreased 15% and 3% under MW/SPS/TBA and MW/H2O2/TBA respectively (Figure 5). According to Eqs. (11) to (16) [37] is cleared that both SO40− and OH0 can degrade PCP, but with respect to TBA test, SO40− in MW/SPS play the dominant role and OH0 had only a negligible role (15%).
O 3 S O O S O 3 2 O 3 S O 0
O 3 S O 0 + e SO 2 4
O 3 S O 0 + PCP Products
O 3 S O 0 + H 2 O HSO 4 + OH 0
O 3 S O 0 + HO SO 2 4 + OH 0
OH 0 + PCP Products
Figure 5
Figure 5

Effect of TBA on PCP removal under MW/SPS and MW/H 2 O 2 systems (pH = 11, PCP = 100mg L −1 , SPS and H 2 O 2 dose = 0.02, 0.2 mol L −1 , TBA = 0.04 mol L −1 , E = 600 W, reaction time = 30 min).

MW/H2O2/TBA results show that OH0 is activation initiator and isn’t dominant radical (its role was only 3%). Based on following equations, MW is able to dissociate H2O2 to many radicals as well as OH0[6, 28, 38]. Also according to Hong et al. results in MW/H2O2 system, O2 is dominant radical [9].
H 2 O 2 + MW 2 O H 0
O H 0 + H 2 O 2 H 2 O + H O 2 0
2 O H 0 H 2 O 2
2 O H 0 H 2 O 2 + O 2
O H 0 O 2 + H +
H 2 O + H O 2 0 + O 2 H 2 O 2 + O 2 + O H

Reaction kinetics

Obtained Results from reaction kinetics under MW/SPS and MW/H2O2 demonstrated that the PCP removal follows first-order kinetics law (Figure 6). In this study, K SPS and K H2O2 only was 0.014 min−1 and 0.004 min−1 respectively, but K MW/SPS and K MW/H2O2 was 0.095 min−1 and 0.055 min−1 respectively. So that, K SPS was 3.5 times more than K H2O2, and K MW/SPS was 1.72 times more than K MW/H2O2. Because energy of oxygen-oxygen bond in persulfate is less than H2O2[15], SPS activation and subsequently PCP removal occur more rapidly in MW/SPS system than MW/H2O2. Also synergetic factor of MW in MW/SPS and MW/H2O2 was 6.6 and 13.75 respectively. This factor shows that MW process have higher synergetic effect on H2O2 decomposition than SPS [39].
Figure 6
Figure 6

Reaction kinetics of PCP removal under different processes (pH = 11, PCP = 100 mg L −1 , SPS, H 2 O 2 dose = 0.02, 0.2 mol L −1 , E = 600 W, reaction time = 30 min).

Mineralization of PCP in MW/SPS and MW/H2O2 processes and identification of oxidation intermediates

Results abstained from COD removal showed that MW/SPS and MW/H2O2 were able to remove COD in amount of 94 and 83% respectively (Figure 7). Intermediates detected via HPLC were CO2 and HCL (Eq. 23). In this study, the HPLC spectra and COD results showed a similar trend in mineralization and the lack of toxic intermediates and by products [28, 39].
Figure 7
Figure 7

Mineralization of PCP in MW/SPS and MW/H 2 O 2 processes and identification of oxidation intermediates (pH = 11, COD = 344 mg/L, SPS and H 2 O 2 dose = 0.02 and 0.2 mol L −1 , E = 600 W).

C 6 HCL 5 O + MW CO 2 + 5 HCl


MW/SPS and MW/H2O2 processes could efficiently degrade refractory compounds at strong alkaline, via radical production. MW/SPS in PCP removal was more effective than MW/H2O2, because SPS is dissociated and activated more easily than hydrogen peroxide. Addition of SPS and H2O2 doses during MW process enhances the rate of PCP degradation, except when the radical scavenging effects of SPS and H2O2. Results obtained from radical scavenger test showed that OH° had only an initiator role, and had not a dominant role and order reaction in both of systems was in first order. Also, the microwave degradation is able to mineralize refractory compounds without any toxic byproduct. The microwave degradation has many advantages such as convenience, safety, economy and high efficiency. Accordingly these methods, especially WM/SPS, have a better prospect in future for removal of other chlorinated organic compounds such as Aldrin, Dieldrin and Lindane, in alkaline pH.





Advanced oxidation processes


Tert- butyl alcohol


Chemical oxygen demand


Sodium Persulfate


Hydrogen Peroxide




Reaction constant.



The authors would like to thank Hamadan University of Medical Sciences for technical and financial support of this work (9010274023).

Authors’ Affiliations

Social Determinants of Health Research Center (SDHRC), Department of Environmental Health Engineering, School of Public Health, Hamadan University of Medical Sciences, Hamadan, Iran
Social Determinants of Health Research Center (SDHRC), Department of Environmental Health Engineering, Gonabad University of Medical Sciences, Gonabad, Iran


  1. Navarro AE, Cuizano NA, Lazo JC, Sun-Kou MR, Llanos BP: Comparative study of the removal of phenolic compounds by biological and non-biological adsorbents. J Hazard Mater 2009, 164: 1439–1446. 10.1016/j.jhazmat.2008.09.077View ArticleGoogle Scholar
  2. Ewers U, Krause C, Schulz C, Wilhelm M: Reference values and human biological monitoring values for environmental tox-ins. Int Arch Occup Environ Health 1999, 72: 255–260. 10.1007/s004200050369View ArticleGoogle Scholar
  3. Stehly GR, Hayton WL: Effect of pH on the accumulation ki-netics of pentachlorophenol in goldfish. Arch Environ Contam Toxicol 1990, 19: 464–470. 10.1007/BF01054993View ArticleGoogle Scholar
  4. Song Z: Effects of Pentachlorophenol on Galba pervia, Tubifex sinicus and Chironomus plumousus Larvae. Bull Environ Con-tam Toxicol 2007, 79: 278–282. 10.1007/s00128-007-9258-8View ArticleGoogle Scholar
  5. Jorens PG J, Schepens PJC: Human pentachlorophenol poisoning. Hum Exp Toxi 1993, 12: 479–495. 10.1177/096032719301200605View ArticleGoogle Scholar
  6. Asgari G, Seidmohammadi AM, Chavoshani A, Rahmani AR: Microwave/H 2 O 2 Efficiency in Pentachlorophenol Removal from Aqueous Solutions. JRHS 2014, 4: 36–39.Google Scholar
  7. Fisher B: Pentachlorophenol: toxicology and environmental fate. J Pestic Reform: A Publ Northwest Coalit Altern Pestic 1991, 11: 1–5.Google Scholar
  8. Remya N, Lin JG: Current status of microwave application in wastewater Treatment—a review. Chem Eng J 2011, 166: 797–813. 10.1016/j.cej.2010.11.100View ArticleGoogle Scholar
  9. Hong J, Yuan N, Wang Y, Qi S: Efficient degradation of Rho-damine B in microwave-H 2 O 2 system, at alkaline pH. Chem Eng J 2012, 191: 364–365.View ArticleGoogle Scholar
  10. Rodriguez M: Comparison of different advanced oxidation processes for phenol degradation. Water Res 2002, 36: 1034–1042. 10.1016/S0043-1354(01)00301-3View ArticleGoogle Scholar
  11. Movahedyan H, Seidmohammadi AM: Comparison of different advanced oxidation process degradation P-cholorophenol in aqueous solutions. Iran J Environ Health 2009, 6: 153–160.Google Scholar
  12. Lam SS, Chase HA: A Review on Waste to Energy Processes Using Microwave Pyrolysis. Energies 2012, 5: 4209–4232. 10.3390/en5104209View ArticleGoogle Scholar
  13. Lidstrom P, Tierney J, Wathey B, Westman J: Microwave assisted organic synthesis- a review. Tetrahedron 2001, 57: 9225–9283. 10.1016/S0040-4020(01)00906-1View ArticleGoogle Scholar
  14. Nyfors E: Industrial microwave sensors—A review. Sub Sen Tech Appl 2000, 1: 23–43. 10.1023/A:1010118609079View ArticleGoogle Scholar
  15. Raharinirina D, Ramanantsizehena G, Razafindramisa FL, Leitner NKV: Comparison of UV/H 2 O 2 and UV/S 2 O 8 2- processes for the decoloration of azo dyes Congo Red in various kinds of water. 2012, 114: 1–9.Google Scholar
  16. Anipsitakis GP, Dionysiou DD, Gonzalez MA: Cobalt-mediated activation of peroxymonosulfate and sulfate radical attack on phenolic compounds. Implications of chloride ions. Environ Sci Technol 2006, 40: 1000–1007. 10.1021/es050634bView ArticleGoogle Scholar
  17. Daneshvar N, Rabbani M, Modirshahla N, Behnajady M: Critical effect of hydrogen peroxide concentration in photochemical oxidative degradation of CI Acid Red 27 (AR27). Chemosphere 2004, 56: 895–900. 10.1016/j.chemosphere.2004.06.001View ArticleGoogle Scholar
  18. Anotai J, Wuttipong R, Visvanathan C: Oxidation and detoxifi-cation of pentachlorophenol in aqueous phase by ozonation. J Environ Manage 2007, 85: 345–349. 10.1016/j.jenvman.2006.10.001View ArticleGoogle Scholar
  19. Association APH: Standard methods for the examination of water and waste water. Washington DC: APHA; 2005.Google Scholar
  20. Al-Momani F: Combination of photo- oxidation process with biological treatment, [PhD thesis]. Barcelona: Barcelona University of Environmental Engineering; 2003.Google Scholar
  21. Abu Amr SS, Aziz HA, Adlan MN, Bashir MJ: Pretreatment of stabilized leachate using Ozone/Persulfate oxidation process. Chem Eng J 2013, 221: 492–499.View ArticleGoogle Scholar
  22. Lin YT, Liang C, Chen JH: Feasibility study of ultraviolet activated persulfate oxidation of phenol. Chemosphere 2011, 82: 1168–1172. 10.1016/j.chemosphere.2010.12.027View ArticleGoogle Scholar
  23. Yuan R, Ramjaun SN, Wang Z, Liu J: Effects of chloride ion on degradation of Acid Orange 7 by sulfate radical-based advanced oxidation process: implications for formation of chlorinated aromatic compounds. J Hazard Mater 2011, 196: 173–179.View ArticleGoogle Scholar
  24. Furman OS, Teel AL, Ahmad M, Merker MC, Watts RJ: Effect of basicity on persulfate reactivity. J Environ Eng 2010, 137: 241–247.View ArticleGoogle Scholar
  25. Liang C, Liang CP, Chen CC: pH dependence of persulfate activation by EDTA/Fe (III) for degradation of trichloroethylene. J Contam Hydrol 2009, 106: 173–182. 10.1016/j.jconhyd.2009.02.008View ArticleGoogle Scholar
  26. Neppolian B, Doronila A, Ashokkumar M: Sonochemical oxidation of arsenic (III) to arsenic (V) using potassium peroxydisulfate as an oxidizing agent. Water Res 2010, 44: 3687–3695. 10.1016/j.watres.2010.04.003View ArticleGoogle Scholar
  27. Liang C, Wang ZS, Bruell CJ: Influence of pH on persulfate oxidation of TCE at ambient temperatures. Chemosphere 2007, 66: 106–113. 10.1016/j.chemosphere.2006.05.026View ArticleGoogle Scholar
  28. Han DH, Cha SY, Yang HY: Improvement of oxidative decomposition of aqueous phenolby microwave. Water Res 2004, 38: 2782–2790. 10.1016/j.watres.2004.03.025View ArticleGoogle Scholar
  29. Shih Y, Chen MY, Su YF: Pentachlorophenol reduction by Pd/Fe bimetallic nanoparticles: effects of copper, nickel, and ferric cations. App Catal B- Environ 2011, 106: 24–29.View ArticleGoogle Scholar
  30. Shih YJ, Putra WN, Huang YH, Tsai JC: Mineralization and deflourization of 2, 2, 3, 3-tetrafluoro-1-propanol (TFP) by UV/persulfate oxidation and sequential adsorption. Chemosphere 2012, 89: 1262–1266. 10.1016/j.chemosphere.2012.08.010View ArticleGoogle Scholar
  31. Olmez HT, Arslan AI, Genc B: Bisphenol A Treatment by the Hot Persulfate Process: Oxidation Products and Acute Toxicit y . J Hazard Mater 2013, 263: 283–290.View ArticleGoogle Scholar
  32. Nuechter M, Mueller U, Ondruschka B, Tied A, Lautenschlaeger W: Microwave - Assisted Chemical Reactions. Chem Eng Technol 2003, 26: 1207–1216. 10.1002/ceat.200301836View ArticleGoogle Scholar
  33. Yang Y, Wang P, Shi S, Liu Y: Microwave enhanced fenton-like process for the treatment of high concentration pharmaceu-tical wastewater. J Hazard Mater 2009, 168: 238–245. 10.1016/j.jhazmat.2009.02.038View ArticleGoogle Scholar
  34. Zeng H, Lu L, Liang M, Liu J, Li Y: Degradation of trace nitrobenzene in water by microwave-enhanced H 2 O 2 -based process. Frontenviron Sci Technol 2012, 6: 477–483.Google Scholar
  35. Lin L, Chen J, Xu Z, Yuan S, Cao M, Liu H, Lu X: Removal of ammonia nitrogen in wastewater by microwave radiation: a pilot-scale study. J Hazard Mater 2009, 168: 862–867. 10.1016/j.jhazmat.2009.02.113View ArticleGoogle Scholar
  36. Alibas I: Microwave, air and combined microwave–air-drying parameters of pumpkin slices. LWT-Food Sci Tech 2007, 40: 1445–1451. 10.1016/j.lwt.2006.09.002View ArticleGoogle Scholar
  37. Yang S, Wang P, Yang X, Wei G, Zhang W, Shan L: A novel advanced oxidation process to degrade organic pollutants in wastewater: Microwave-activated persulfate oxidation. J Envi-ron Sci 2009, 21: 1175–1180. 10.1016/S1001-0742(08)62399-2View ArticleGoogle Scholar
  38. Zhao D, Cheng J, Hoffmann MR: Kinetics of microwave-enhanced oxidation of phenol by hydrogen peroxide. Front Environ Sci Eng China 2011, 5: 57–64. 10.1007/s11783-010-0251-9View ArticleGoogle Scholar
  39. Lee HY, Lee CL, Jou CJG: Comparison degradation of penta-chlorophenol using microwave-induced nano scale Fe 0 and activated carbon. Water Air Soil Poll 2010, 211: 17–24. 10.1007/s11270-009-0276-5View ArticleGoogle Scholar


© Asgari et al.; licensee BioMed Central Ltd. 2014

This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly credited. The Creative Commons Public Domain Dedication waiver ( applies to the data made available in this article, unless otherwise stated.