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Pilot-scale treatment of olive oil mill wastewater by physicochemical and advanced oxidation processes a

a

M. Yalılı Kılıç , T. Yonar & K. Kestioğlu

a

a

Department of Environmental Engineering , Uludag University , Bursa , Turkey Published online: 08 Jan 2013.

To cite this article: M. Yalılı Kılıç , T. Yonar & K. Kestioğlu (2013) Pilot-scale treatment of olive oil mill wastewater by physicochemical and advanced oxidation processes, Environmental Technology, 34:12, 1521-1531, DOI: 10.1080/09593330.2012.758663 To link to this article: http://dx.doi.org/10.1080/09593330.2012.758663

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Environmental Technology, 2013 Vol. 34, No. 12, 1521–1531, http://dx.doi.org/10.1080/09593330.2012.758663

Pilot-scale treatment of olive oil mill wastewater by physicochemical and advanced oxidation processes M. Yalılı Kılıç∗ , T. Yonar and K. Kestio˘glu Department of Environmental Engineering, Uludag University, Bursa, Turkey

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(Received 12 July 2012; final version received 27 November 2012 ) The pilot-scale treatability of olive oil mill wastewater (OOMW) by physicochemical methods, ultrafiltration and advanced oxidation processes (AOPs) was investigated. Physicochemical methods (acid cracking, oil separation and coagulation– flocculation) showed high efficiency of chemical oxygen demand (COD) (85%), oil and grease (O&G) (>97%), suspended solids (SS) (>99%) and phenol (92%) removal from the OOMW. Ultrafiltration followed by physicochemical methods is effective in reducing the SS, O&G. The final permeate quality is found to be excellent with over 90% improvements in the COD and phenol parameters. AOPs (ozonation at a high pH, O3 /UV, H2 O2 /UV, and O3 /H2 O2 /UV) increased the removal efficiency and the O3 /H2 O2 /UV combination among other AOPs studied in this paper was found to give the best results (>99% removal for COD, >99% removal for phenol and >99% removal for total organic carbon). Pilot-scale treatment plant has been continuously operated on site for three years (3 months olive oil production campaign period of each year). The capital and operating costs of the applied treatment alternatives were also determined at the end of these seasons. The results obtained in this study have been patented for 7 years by the Turkish Patent Institute. Keywords: advanced oxidation processes; cost analysis; olive oil mill wastewater; pilot scale; physicochemical processes

Introduction The production of olive oil, an important agricultural product, has intensified in the Mediterranean region and become widespread throughout the world [1]. Mediterranean countries alone produce 97% of the world’s olive oil, while European Union (EU) countries produce 80–84%. The biggest olive oil producer worldwide is Spain, followed by Italy, Greece and Turkey, as well as Tunisia, Portugal, Morocco and Algeria. Outside the Mediterranean area, olives are cultivated in the Middle East, the USA, Argentina and Australia [2]. Turkey has the second and fourth biggest shares in the global markets of table olives and olive oil production, respectively [3]. Olive oil mill wastewater (OOMW) is generated either in the two-phase olive oil production process with olive pomace or in the three-phase olive oil production process alone. OOMW is a serious environmental problem because of its high organic content, suspended solids (SS), high concentrations of recalcitrant compounds and resistance to biodegradation caused by its high level of polyphenol. Polyphenol is also responsible for the dark colour, phytotoxic effects and antibacterial activity of the OOMW [4,5]. Treatment of OOMW is very difficult due to its distinct characteristics, including high chemical oxygen demand (COD), biological oxygen demand (BOD), oil and grease (O&G) and phenol content. The BOD concentration of OOMW ∗ Corresponding

author. Email: [email protected]

© 2013 Taylor & Francis

is approximately 15,000–135,000 mg/L, the COD concentration is 37,000–318,000 mg/L, the SS concentration is 6000–69,000 mg/L and the pH value is 4.6–5.8 [6]. Many different processes have been proposed for the treatment of OOMW: lagooning or direct watering on fields [7], the use of evaporation ponds [8], land disposal [9], co-composting [10], chemical treatment [11], electrochemical treatment [12,13], electro-Fenton [14] ultrafiltration/reverse osmosis [15], adsorption [16], aerobic treatment [17,18], and anaerobic treatment [19]. All of the treatment options have been applied on OOMW as a single treatment and showed significant results. However, a single treatment is not enough to meet the environmental discharge criteria. In the literature, many combined processes have been examined for the treatment of OOMW: electro-Fenton and anaerobic treatment [20], chemical and biological treatment [21], UF and UV/H2 O2 techniques [22], ozonation and aerobic treatment [23], nanofiltration and reverse osmosis [24], coagulation and advanced oxidation processes (AOPs) [25], coagulation, advanced oxidation and aerobic treatment [26]. Most of these treatment methods were carried out on a laboratory scale. Studies related to the treatment of OOMW on a pilot scale are not frequently found in the literature. Typical examples of OOMW treatment on a pilot scale have been performed in some studies [5,27–35]. Most of these applications are

1522 Table 1.

M. Yalılı Kılıç et al. Characterization of the OOMW sample.

Parameter (g/L, except for pH)

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pH COD SS O&G Phenol TOC

Kestio˘glu et al. [37]

Ölmez-Hanci et al. [42]

Dogruel et al. [43]

Kiril Mert et al. [44]

This study

4.65–5.5 185.6 ± 23.8 65 ± 8 35 ± 3.4 9.68 ± 1.18 –

4.3 52.774 1.365 7.93 – 18.65

4.6 39.24 5.31 – – 13.43

5.2 115 32 23 5.58 –

4.91 128 ± 1 36.3 ± 0.492 8.92 ± 0.199 3.44 ± 0.151 26.4 ± 0.4

related to biological treatment or constructed wetlands. Biological processes are considered environmentally friendly and reliable. These processes are also able to remove organic matter and inorganic nutrients [2]. Biological methods used for OOMW treatment are aerobic activated sludge and anaerobic digestion. Because of their antibacterial effects, phenolic compounds are the main drawback to OOMW degradation by anaerobic processes. In some cases, biological methods are very expensive and give rise to sludge or other by-products that need to be further disposed of or treated [29]. In recent years, there has been increasing interest in the use of AOPs for the treatment of wastewater. AOPs constitute a suitable treatment method for industrial effluents because these processes rely on the effects of chemical initiators (i.e. free radicals) and energy (i.e. heat) to destroy the target pollutants. Given the specific treatment objectives, AOP may be used either for the complete mineralization of all pollutants to carbon dioxide, water and mineral salts, or for the selective removal of more bioresistant pollutants and their conversion to biodegradable intermediates [36]. AOPs have been extensively studied regarding their efficiency to treat OOMW, and high removal efficiencies have been reported. Kestio˘glu et al. [37] obtained the same COD and total phenol removal efficiencies (over 99% removal for both COD and total phenol) when utilizing both H2 O2 /UV and O3 /UV combinations. The results show that 95% colour and 90% COD removal efficiencies were obtained through H2 O2 /UV 100% phenol removal efficiency [38,39]. Beltran et al. [40] reported that 80–90% COD removal was achieved by using an O3 /H2 O2 /UV process. In the ozonation studies performed by Karageorgos et al. [41], 10–60% COD and 50–90% phenol removal efficiencies were obtained. In ozonation studies performed by Paraskeva and Diamadopoulos [2], 18–20% COD and almost complete phenol removal efficiencies were obtained. The aim of this study is to investigate and compare different treatment methods to find a suitable alternative to treat OOMW in an economical and feasible way at an on-site pilot-scale treatment plant. Acid cracking, oil separation, chemical coagulation–flocculation, sand filter and microfiltration, ultrafiltration and AOPs (ozonation at high pH, O3 /UV, H2 O2 /UV, and O3 /H2 O2 /UV) were applied at a pilot plant, and the results of these treatment methods are presented in this report. The capital and operating costs of

all proposed treatment alternatives were also evaluated in this study. Materials and methods Wastewater samples Wastewater samples used in this study were obtained from the homogenization tank of an olive oil mill plant in Bursa (western Turkey) with a daily olive oil processing capacity of 120,000 kg. The 3-year average characteristics of the OOMW are shown in Table 1 [37,42–44]. Turkish Water Pollution Control regulations stipulate OOMW effluent parameters for COD, O&G, colour and pH only [45]. Final discharge concentrations of the COD, O&G and colour parameters must be lower than 230 mg/L, 40 mg/L, and 260 Pt-Co, respectively. The pH limit for the discharge in this regulation is 6–9. The levels of these parameters in raw OOMW are higher than the discharge limits. Other conventional and important environmental parameters such as total phenol, SS, total nitrogen (totalN) and total phosphorus (total-P) levels are not included in this regulation. Laboratory-scale experiments Acid cracking and coagulation-flocculation experiments The first studied method of treatability was acid cracking, and it was applied to the OOMW by adjusting the pH to 3 using technical sulphuric acid on a pilot scale. The reaction time of this process is 3 h. The OOMW samples were then heated to 60–70◦ C, and the oily parts of the OOMW were peeled off the samples. The second studied method of treatability was chemical treatment on a pilot scale. The optimum coagulant dose and pH values found in laboratory experiments were used directly in this process. Coagulation experiments were carried out with 1 L of OOMW using a Jar-Test apparatus (Velp Scientifica FC6S model, Italy) equipped with six mixers and nine stirring speed modes on a laboratory scale. The coagulants used were FeCl3 ·6H2 O and Al2 SO4 .18H2 O (supplied from Merck, Germany) at varying dosages and pHs. Coagulation experiments were conducted in the following manner: • Coagulant addition • pH adjustment

Environmental Technology • Flash-mixing (stirring for 5 min at 120 rpm) • Flocculation (stirring for 30 min at 30 rpm) • Settling for 60 min

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At the end of settling period, the supernatants were analysed. The optimum pH and reagent dose that provide the best COD removal were determined for FeCl3 ·6H2 O at room temperature (20◦ C) on a laboratory scale. These values were then used on a pilot scale. Advanced oxidation processes A photoreactor was set up for the experiments with UV in batch mode operation in laboratory-scale experiments. A TUV-16 model Phillips 16 W lamp (wavelength of λ = 254 nm) enclosed in a quartz sleeve with an inner diameter of 40 mm and a length of 40 cm was positioned within the centre of a 1.5 L cylindrical stainless steel reactor as the light source. The body of the reactor was made of 316-Ti stainless steel with an inner diameter of 78 mm and a length of 41 cm. The diameter of the reactor was selected according to actinometric measurements performed to determine the length of the radiation emitted by the lamp. The three-dimensional fluence rate (irradiance) distribution of photoreactor was calculated by UVCalc 1.05 software and average fluence rate determined as 0.3– 0.88 mW cm−2 (designed by Bolton Photosciences Inc.). A water jacket and thermostat were installed around the reactor to keep the reactor at the desired temperature by means of continuous water recirculation. The wastewater sample and recirculating cooling solution never came into contact with one another. The content of the reactor was mixed with a magnetic stirrer. The ozone experiments were performed in a reactor designed to provide good contact between the liquid and gas phases. The reactor was made of Pyrex glass and had a total volume of 2 L. An Opal 200 model ozone generator with an ozone production rate of 2 g/h produced the ozone needed in the reaction. The ozone produced by using oxygen with a purity of 99.5% was bubbled into the reactor by means of a diffuser. The experiments with ozone alone were carried out at varying pH values between 3 and 9 at 20◦ C. Inlet and outlet of ozone from the reactor were directed to the gas washing bottles filled with 2% w/w potassium iodide (KI) solution for the determination of ozone concentration. The ozone gas flow rate was adjusted to 2000 mg/h before all experiments. Ozone usage ratios varied in the range of 2% (pH 3) to 21% (pH 12) for the applied treatment period. The reactor was always charged with 1.5 L of acid cracking applied OOMW. Samples were taken at regular time intervals for determination of the COD. All experiments were performed in batch mode. Pilot-scale treatment plant A pilot plant was established for testing the data obtained from the laboratory-scale treatability study results. The

1523

system capacity was 5 m3 /day, and the schematic flow diagram of the pilot-scale experiments used in this study is shown in Figure 1. This diagram includes an equalization tank (H = 2 m, B = 2 m, L = 2 m); acid cracking at low pH (D = 0.04 m, H = 0.28 m); a flocculation tank (H = 1 m, B = 0.5 m, L = 0.5 m); an oil separation tank (H = 1 m, B = 1.5 m, L = 1 m); coagulation, flocculation and chemical sedimentation tanks (H = 1 m, B = 1 m, L = 1 m); and a sand filter, microfiltration unit, ultrafiltration unit and AOPs. The sand filter applied prior to ultrafiltration had a capacity of 3 m3 /h and consisted of anthracite and microfiltration with a 10 micron core size. A sand filter with the same capacity was also applied prior to ultrafiltration. The microfiltration housing was 120 cm in height and 30 cm in diameter. The experimental apparatus used for this study consisted of a stainless steel UF system made by Norit AquaFlex. The UF unit has a hydrophilic, spiral-wound tube of PVC membrane. It has an 8” inner diameter and is 2 m in length. In a semi-dead end system, all of the feed supplied to the system exits as permeate. The capacity is controlled by adjusting the transmembrane pressure. At regular time intervals, the system is subjected to an AirFlush with a backwash to remove the retained particles. Adsorbed substances are removed by an in situ chemically enhanced backwash. Two reactors, each with a 53 L volume, were used in AOPs on a pilot scale. The body of the reactors was made from stainless steel, and the length and diameter was 162 cm and 20.4 cm, respectively. The operating pressure in this system is 2–8 bar. Four UV lamps with 254 nm wavelength were used in this system. Total UV lamp power and UV dosage are 3 kW and 30,000 microwatt/cm2 , respectively. Raw OOMW was conveyed to the equalization tank with a pump (P = 0.25 kWh) and a level-control relay. The OOMW was equalized for approximately 6 h. Wastewater was then transferred to the acid cracking tank by a pump, and technical sulphuric acid was added in a flash-mixing unit until the pH reached 3. The acidified wastewater was mixed slowly in the flocculation tank for 30 min with a 30–45 cycle/min (P = 0.37 kWh) mixing speed. After this process, the oily part of the OOMW was separated in the oil separation tank by heating the wastewater temperature with thermostat-controlled resistances of approximately 60–70◦ C (P = 7.5 kWh). The oily part from this unit was stored in the oily sludge storage tank, and the supernatant was transferred to the second flash-mixing unit for treatment of the supernatant with a chemical additive. Initially, FeCl3 .6H2 O and NaOH/lime were pumped into the flash mixer and slowly mixed for 30 min at 30–45 cycle/min (P = 0.37 kWh) in the flocculation tank. Wastewater from the flocculation tank was transferred to the sedimentation tank, which required 2–4 h of retention for particle precipitation. Clarified water from the chemical treatment was first transferred to the sand filter by hydrophore and then microfiltration. Effluent from the microfiltration was directed to the ultrafiltration unit. Effluent from ultrafiltration unit was

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M. Yalılı Kılıç et al. 2.1

A

4.1

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4

5.3 5.1 pH

5.2

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7 8

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C

1: Equalization tank 2, 5: Flash mixing 2.1: Sulfuric acid 3, 6: Slow mixing tank 4: Heated oil seperation tank 4.1: Oily sludge stockage tank 4.2: Resistance 5.1: Ferric (III) chloride 5.2: Sodium hydroxide 5.3: Lime 7: Settling tank 8: Sand filter 9: Microfiltration unit

F

10: Ultrafiltration unit 11: H2O2/UV tank 12: O3/UV tank 13: Ozonation tank 14: O3/H2O2/UV tank A: Olive oil mill wastewater B:Oily sludge treatment/recycling C: Sludge D: Ozone E: Hydrogen peroxide F: pH adjustment G: Discharge water

G

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E F

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Figure 1.

Schematic flow diagram of the pilot-scale experiments for OOMW treatment.

sent to AOPs to achieve high-quality water. Following these processes, a pH adjustment was carried out, and the refined water was discharged from the system.

Analytical procedure To decompose residual H2 O2 , which interferes with the COD, the samples containing H2 O2 were treated with MnO2 powder [46,47]. The concentration of residual H2 O2 in the test solution was measured using test strips (Merck Merckoquant Peroxide Test). Before each analysis, the samples were centrifuged and filtered on 0.45 μm Millipore membranes to remove MnO2 . COD (closed reflux method), O&G, SS, TOC and phenol were measured in accordance with Standard Methods [48].

Results and discussion Acid cracking and coagulation–flocculation experiments As mentioned in the Materials and methods, the COD and phenol removal experiments included three processes (chemical coagulation, ultrafiltration and oxidation) after acid cracking to compare the results. Characteristics of OOMW after acid cracking are shown in Table 2. Acid cracking resulted in the removal of 73% COD, 21% phenol and a significant amount of SS (90%) and O&G (95%). Al2 (SO4 )3 .18H2 O and FeCl3 .6H2 O were used during the

chemical treatment experiments with varying dosages under varying pH conditions after acid cracking. The optimum pH value, optimum coagulant dosage and the amounts of COD, phenol, SS and O&G removed are shown in Table 2. However, the results of coagulation experiments using Al2 (SO4 )3 .18H2 O are not shown in Table 2, because the removal efficiencies of COD and SS were very low compared with the coagulation experiments using FeCl3 .6H2 O. COD removal at a FeCl3 .6H2 O dosage of 2500 mg/L resulted in an effluent COD of 18,880 mg/L (85%), phenol of 284 mg/L (92%), SS of 200 mg/L (99%) and O&G of 240 mg/L (97%) at a pH of 9. These removal efficiencies are higher than those found in a study performed by Kiril Mert et al. [44]. These authors found 67% COD, 72% phenol, >99% O&G, >99% SS removal by acid cracking (at pH 2) and coagulation with a FeCl3 .6H2 O dosage of 4000 mg/L. The difference in removal efficiencies may be due to differences in the characterization of the wastewater and the study location conditions. The study by Kiril Mert et al. was carried out on a laboratory scale, and our study was performed on a pilot scale. The OOMW supernatants remaining after the chemical treatment were then used in filtration experiments. Sand filter, microfiltration and ultrafiltration processes After pretreatment by acid cracking and coagulationflocculation, the OOMW underwent sand filtration,

Environmental Technology Table 2.

Acid cracking, coagulation and ultrafiltration results of OOMW.

Process

Optimum Optimum chemical dosage pH (conc. H2 SO4 volume)

Acid cracking Acid cracking + coagulation with FeCl3 .6H2 O Acid cracking + coagulation with FeCl3 .6H2 O + Ultrafiltration

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1525

3 9

5 mL/L 2500

9



microfiltration and ultrafiltration to reduce the contaminants in the wastewater. The results from these processes are shown in Table 2. Although SS and O&G were completely removed from the OOMW, the removal of COD and phenol was limited to 97% and 99%, respectively. These removal efficiencies are consistent with the removal efficiencies found in the literature. The efficiency of COD removal by ultrafiltration was found to be 94% by Drouiche et al. [22], 90% by Oktav Akdemir and Ozer [49] and 90% by Turano et al. [50]. Mameri et al. [51] obtained 85–90% COD removal using polymeric membrane filtration on a pilot scale. Following the acid cracking and chemical pretreatment, COD was 3568 mg/L after the filtration processes, and this level is still considered to be a high value according to the Turkish Water Pollution Control Regulation, which mandates that the COD in effluent should be lower than 230 mg/L [45]. Therefore, AOPs were applied on the effluent of the ultrafiltration process to reduce the COD content of the OOMW. Advanced oxidation processes In this study, oxidation experiments on the OOMW after filtration were first carried out using the combinations of O3 /UV, ozonation, H2 O2 /UV and O3 /H2 O2 /UV processes on a laboratory scale to assess the COD and phenol removal efficiencies of these processes. The oxidation experiments were then conducted on a pilot scale. The experiments were carried out at pH values of 3, 5, 7, 9, 11 and 12 for the O3 /UV and ozonation processes and 3, 5, 7 and 9 for the H2 O2 /UV and O3 /H2 O2 /UV processes to observe the effect of pH on the COD removal. The optimum pH that results in the highest COD and phenol removal was determined by initially running the photoreactor under varying pHs but constant H2 O2 conditions for the H2 O2 /UV experiments (Figure 2(a)). The optimum pH value was found to be 3 for the H2 O2 /UV process, which is similar to that found in studies performed by Arslan and Akmehmet Balcio˘glu [52], Muruganandham and Swaminathan [53], Zayas et al. [54], and Garcia et al. [55]. At lower operating pH values for the UV/H2 O2 process, the effect of radical scavengers, especially ionic, such as carbonate and bicarbonate ions, can be nullified, leading to higher overall rates of degradation. On the other hand, increasing pH

COD (g/L)

Phenol (g/L)

35.2 ± 0.73 18.88 ± 0.43

2.71 ± 0.075 0.284 ± 0.0065

3.568 ± 0.124 0.0114 ± 0.00013

SS (g/L)

O&G (g/L)

3.7 ± 0.19 0.44 ± 0.034 0.2 ± 0.01 0.024 ± 0.005 –



values can increase the decomposition rate of hydrogen peroxide itself to water and oxygen. Thus, it is better to lower the operating pH for UV/H2 O2 process [56]. The H2 O2 /UV experiments were then performed at a pH of 3 with varying H2 O2 dosages between 500 and 900 mg/L (Figure 2(b)). The COD decreased to 1560 and 1944 mg/L for H2 O2 dosages of 800 and 900 mg/L, respectively, at the end of the 180 min reaction time (the initial COD was 3568 mg/L). The same experiment was carried out at a H2 O2 dose of 800 mg/L to observe the phenol removal together with the COD removal. The initial phenol was decreased to 2.76 mg/L at the end of the 180 min reaction time, and over a 99% removal was obtained. The same ozone generator was integrated into the photoreactor during O3 /UV, H2 O2 /UV and O3 /H2 O2 /UV experiments. In the second part of the oxidation experiments, an O3 /H2 O2 /UV process was applied to the OOMW samples after pretreatment by acid cracking, coagulation and filtration. An Opal 200 model ozone generator with an ozone production rate of 0.3 g/h produced the ozone needed for the reaction. Determination of the optimum pH value is a significant factor for the O3 /H2 O2 /UV process [57,58]. The best pH level for optimum COD removal was determined by testing pH values of 3, 5, 7 and 9. The most effective pH range for the O3 /H2 O2 /UV process is 3–7 according to Legrini et al. [59], Azbar et al. [47], and Gogate and Pandit [56]. Figure 3(a) shows the effects of various pH levels on the removal of the COD by the O3 /H2 O2 /UV process. Acidic conditions resulted in better removal efficiencies, and a pH of 3 gave the best COD removal. Therefore, the O3 /H2 O2 /UV experiment was run at a pH of 3 for 180 min of reaction time to determine the optimum H2 O2 dosage between 500 and 800 mg/L (Figure 3(b)). The COD decreased to 1410 mg/L for an H2 O2 dosage of 700 mg/L, and 99% removal was obtained. The same experiment was carried out with an H2 O2 dose of 700 mg/L to observe the phenol removal together with the COD removal. The phenol removal efficiency after 180 min of reaction time was over 99%. Excessive amounts of H2 O2 (Figure 2(b) and Figure 3(b)) created negative effects on the COD removal efficiency. The negative effects could be attributed to the formation of much less powerful OH2 radicals, which are formed by the reaction between hydroxyl radicals and excess hydrogen peroxide [47].

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M. Yalılı Kılıç et al. (a)

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Figure 2. (a) Effect of pH (CH2 O2 = 600 mg/L, T = 20◦ C) and (b) effect of H2 O2 dosages (pH = 3; T = 20◦ C) on the removal of COD during H2 O2 /UV experiments.

In the third part of the oxidation experiments, the O3 /UV and ozonation processes were applied to the OOMW samples after pretreatment by acid cracking, coagulation and filtration. The best pH level for optimum COD removal was determined by testing pH values of 3, 5, 7, 9, 11 and 12. The effects of various pH levels on the COD removal by the O3 /UV and ozonation processes are shown in Figure 4. Alkaline conditions resulted in better removal efficiency; however, pH of 11 and 12 produced similar COD removal results. Therefore, the O3 /UV and ozonation experiments were run at a pH of 12 for a reaction time of 180 min to observe the phenol removal. Phenol concentrations after 180 min of reaction time for the O3 /UV and ozonation processes were found to be 3.08 mg/L and 3.45 mg/L, respectively. The removal efficiencies obtained in this study are consistent with the removal efficiencies found in the literature.

Kestio˘glu et al. [37] studied the treatability of olive mill wastewater by AOPs and found that over 99% of both COD and total phenol were removed using H2 O2 /UV and O3 /UV processes. Benitez et al. [60] removed 41–76% COD by H2 O2 /UV, and Drouiche et al. [22] removed over 99% COD by ultrafiltration and H2 O2 /UV processes. The second and most significant part of this study assessed the treatability of OOMW after ultrafiltration in pilot-scale experiments for the purposes of comparison with the results found in laboratory-scale experiments. The H2 O2 /UV, O3 /H2 O2 /UV, O3 /UV and ozonation processes were applied to the OOMW after ultrafiltration. The same optimum pH values and H2 O2 dosages found in the laboratory-scale experiments were used in the pilot-scale experiments, and the results of these processes are shown in Table 3. The O3 /H2 O2 /UV process resulted in over 99% COD, phenol and TOC removal at the end of the 180 min

Environmental Technology

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Figure 3. (a) Effect of pH (CH2 O2 = 500 mg/L, T = 20◦ C) and (b) effect of H2 O2 dosages (pH = 3; T = 20◦ C) on the removal of COD during O3 /H2 O2 /UV experiments.

reaction time. Although the COD removal efficiencies in the pilot-scale experiments were high, they were not high enough to meet Turkish Water Pollution Control Regulation, which requires the COD in effluent to be 230 mg/L or lower to discharge it into the surface water in Turkey. There have been many studies related to the treatability of OOMW performed on a laboratory scale, but not many studies performed on a pilot scale can be found in the literature. This study is the first in the literature on OOMW treatment performed on a pilot scale with these processes. Therefore, it is difficult to compare this study with other studies. This study has been patented for 7 years by the Turkish Patent Institute [61]. Cost evaluation The overall costs are represented by the sum of the capital costs, the operating costs and the maintenance costs. For a

full-scale system, these costs strongly depend on the flow rate of the effluent and the configuration of the reactor, as well as on the nature of the effluent. The cost evaluation for the UV processes was based on electrical energy per order (EE/M) [62] using the following formula: EE M



kWh kg

 =

Pt × 106 V (Cinf − Ceff )

(1)

where P is the rated power (kW), V is the volume (L) of water treated, t is the time (min) and Cinf and Ceff are the initial and final concentrations of contaminants in the COD (mg/L), respectively. The cost evaluation for 100 m3 /d of OOMW is given in Table 4. The operating costs include power requirements, chemicals, spare parts, plant maintenance and labour. The cost of sludge disposal was excluded in this study. The labour costs are facility specific and depend on the size,

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M. Yalılı Kılıç et al. (a) 4000 pH = 3 pH = 5 pH = 7 pH = 9 pH = 11 pH = 12

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Figure 4.

Effect of pH on the removal of COD during (a) O3 /UV experiments and (b) Ozonation experiments (T = 20◦ C). Table 3. The results of COD, phenol and TOC parameters of H2 O2 /UV, O3 /H2 O2 /UV, O3 /UV and ozonation at high pH on a pilot scale. Parameter (mg/L) COD Phenol TOC Operation pH

H2 O2 /UV

O3 /H2 O2 /UV

O3 /UV

Ozonation at high pH

1088 ± 13.1 2.48 ± 0.02 172 ± 2.6 3

716 ± 29.4 2.16 ± 0.04 156.4 ± 2.4 3

1128 ± 38.03 2.8 ± 0.03 214.4 ± 2.3 12

1184 ± 61.2 3.096 ± 0.009 247.2 ± 0.9 12

location and plant design; therefore, labour costs may vary substantially [63]. The capacity of the OOMW treatment plant can be assumed to be 100 m3 /day. Accordingly, 8 working hours per day and a salary of 18 ¤/day (equal to minimum wage) for two workers as well as 20 ¤/day for an engineer were assumed, and the total labour costs were calculated using a fixed rate of 0.52 ¤/m3 . As with the labour costs, electricity and chemical prices vary by country. For the capital and operating costs, the costs of reagents

(hydrogen peroxide: 0.55 ¤/kg; sulphuric acid: 0.85 ¤/kg; caustic soda: 0.75 ¤/kg; lime: 0.2 ¤/kg; ferric (III) chloride: 0.074 ¤/kg) and electricity (0.087 kWh) consumption were considered. As shown in Table 4, the minimum capital cost of the processes studied in this paper was ¤205,440 and corresponded to the physicochemical treatment + MF + UF + H2 O2 /UV process. The operating costs of the physicochemical treatment + MF + UF + H2 O2 /UV process and the

Environmental Technology Table 4.

Capital and operating costs for the studied processes.

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Capital Operating cost (¤) cost (¤/m3 ) 205,440

6.93

293,040

6.79

247,920

9.51

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7.15

physicochemical treatment + MF + UF + O3 /H2 O2 /UV process were estimated to be 6.93 and 7.15 ¤/m3 , respectively. According to these results, the physicochemical treatment + MF + UF + O3 /H2 O2 /UV process costs are higher than the physicochemical treatment + MF + UF + H2 O2 /UV process because of the ozone usage of the physicochemical treatment + MF + UF + O3 /H2 O2 /UV process. Consequently, although the physicochemical treatment + MF + UF + O3 /H2 O2 /UV process combination among other AOPs methods studied in this paper was found to give the best COD, phenol and TOC results, the physicochemical treatment + MF + UF + H2 O2 /UV process is the more economically viable choice for OOMW treatment. In addition to this cost evaluation, the amount of waste oil has been calculated to be 848 kg/day for 100 m3 /day of OOMW in the olive separation tank. If this waste oil is recovered and sold (3.15 ¤/kg according to the Aegean Olive-Olive Oil Exporter Association [64]), the total income from this waste oil will be 14.24 ¤/m3 . The average income from the wastewater treatment plant may be estimated as approximately 7 ¤/m3 of OOMW. Therefore, an evaluation of the feasibility of oil recycling from OOMW is planned as an additional study.

Conclusions In this study, acid cracking, oil separation, chemical treatment, ultrafiltration and AOPs (ozonation at high pH, O3 /UV, H2 O2 /UV, and O3 /H2 O2 /UV) were applied on OOMW at a pilot plant. The following conclusions can be drawn from this study: i) The results obtained in this study were patented for 7 years by the Turkish Patent Institute [61]. ii) Acid cracking and oil separation have been effective in removing over 90% of SS and O&G from OOMW. iii) The chemical treatment experiments performed using FeCl3 ·6H2 O resulted in the best COD and phenol removal efficiencies. iv) Ultrafiltration is very effective in reducing the SS and O&G concentrations.

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v) Although the O3 /H2 O2 /UV combination was found to give the best result (99% removal for COD, phenol and TOC) of all of the AOPs studied in this paper, this process is not an economic choice for OOMW treatment. vi) The capital and operating cost evaluation suggested that the physicochemical treatment + MF + UF + H2 O2 /UV process provides the most economically viable choice for the OOMW treatment with 99% removal of COD, phenol and TOC. vii) The cost calculation for the recovery of skimmed waste oil indicates that it is possible for the OOMW to become profitable through the sale of the waste oil. Acknowledgements The authors acknowledge the support of the Uludag University Research Projects Department for this study (Project No. M-2008/33).

References [1] M. Yalılı Kılıç, K. Kestio˘glu, and G. Kaya, Physico-chemical treatability of olive mill wastewater (OMW), Süleyman Demirel Üniversitesi J. Nat. App. Sci. 13 (2009), pp. 271– 276. [2] P. Paraskeva and E. Diamadopoulos, Review technologies for olive mill wastewater (OMW) treatment: A review, J. Chem. Technol. Biotechnol. 81 (2006), pp. 1475–1485. [3] N. Azbar, A. Bayram, A. Filibeli, A. Muezzinoglu, F. Sengul, and A. Ozer, A review of waste management options in olive oil production, Crit. Rev. Environ. Sci. Technol. 34 (2004), pp. 209–247. [4] S. Sayadi, N. Allouche, M. Jaoua, and F. Aloui, Detrimental effects of high molecular-mass polyphenols on olive mill wastewater biotreatment, Process Biochem. 35 (2000), pp. 725–735. [5] S. Khoufi, F. Aloui, and S. Sayadi, Pilot scale hybrid process for olive mill wastewater treatment and reuse, Chem. Eng. Process. 48 (2009), pp. 643–650. [6] E. Oktav Akdemir and A. Ozer, Application of microfiltration process to the treatment of olive oil mill wastewater, Electron. J. Environ. Agric. Food Chem. ISSN:1579-4377 (2006), pp. 1338–1348. [7] M. Niaounakis and C.P. Halvadakis, Olive Processing Waste Management: Literature Review And Patent Survey, Elsevier, Amsterdam, 2006, 498 pp. [8] L. Saez, J. Perez and J. Martinez, Low molecular weight phenolics attenuation during simulated treatment of wastewaters from olive oil mills in evaporation ponds, Water Res. 26 (1992), pp. 1261–1266. [9] F. Cabrera, R. Lopez, A. Martinez-Bordiu, E. Dupuy de Lome, and J.M. Murillo, Land treatment of olive oil mill wastewater, Int. Biodeterior. Biodegrad. 38 (1996), pp. 215– 225. [10] G.A. Vlyssides, D.L. Bouranis, M. Loizidou, and G. Karvouni, Study of demonstration plant for co-composting of olive-oil-processing wastewater and solid residue, Bioresour. Technol. 56 (1996), pp. 187–193. [11] S.P. Tsonis, V.P. Tsola, and S.G. Grigoropoulos, Systematic characterization and chemical treatment of olive mill wastewater, Toxicol. Environ. Chem. 20 (1989), pp. 437– 457.

Downloaded by [Nipissing University] at 14:47 18 October 2014

1530

M. Yalılı Kılıç et al.

[12] H. Inan, A. Dimoglo, H. Sim¸ ¸ sek, and M. Karpuzcu, Olive oil mill wastewater treatment by means of electro-coagulation, Sep. Purif. Technol. 36 (2004), pp. 23–31. [13] T. Coskun, F. Ilhan, N. Manav Demir, E. Debik, and U. Kurt, Optimization of energy costs in the pretreatment of olive mill wastewaters by electrocoagulation, Environ. Technol. 33 (2012), pp. 801–807. [14] F. Kaplan, A. Hesenov, B. Gözmen, and O. Erbatur, Degradations of model compounds representing some phenolics in olive mill wastewater via electro-Fenton and photoelectroFenton treatments, Environ. Technol. 32 (2011), pp. 685– 692. [15] A. Cassano, C. Conidi, and E. Drioli, Comparison of the performance of UF membranes in olive mill wastewaters treatment, Water Res. 45 (2011), pp. 3197–3204. [16] K. Al Malah, M.O.J. Azzam, and N.I. Abu Lail, Olive mill effluent (OME) wastewater post-treatment using activated clay, Sep. Purif. Technol. 20 (2000), pp. 225–234. [17] C. Scioli and L. Vollaro, The use of yarrowia lipolytica to reduce pollution in olive mill wastewaters, Water Res. 31 (1997), pp. 2520–2524. [18] E. Jalilnejad, A. Mogharei, and F. Vahabzadeh, Aerobic pretreatment of olive oil mill wastewater using Ralstonia eutropha, Environ. Technol. 32 (2011), pp. 1085–1093. [19] N. Azbar, F. Tutuk, and T. Keskin, Biodegradation performance of an anaerobic hybrid reactor treating olive mill effluent under various organic loading rates, Int. Biodeterior. Biodegrad. 63 (2009), pp. 690–698. [20] S. Khoufi, F. Alouni, and S. Sayadi, Treatment of olive oil mill wastewater by combined process electro-fenton reaction and anaerobic digestion, Water Res. 40 (2006), pp. 2007–2016. [21] M. Bressan, L. Liberatore, N. D’alessandro, L. Tonucci, C. Belli, and G. Ranali, Improved combined chemical and biological treatments of olive oil mill wastewaters, J. Agric. Food Chem. 52 (2004), pp. 1228–1233. [22] M. Drouiche, V. Le Mignot, H. Lounici, D. Belhocine, H. Grib, A. Pauss, and N. Mameri, A compact process for the treatment of olive mill wastewater by combining UF and UV/H 2 O2 techniques, Desalination 169 (2004), pp. 81–88. [23] F.J. Benitez, J. Beltran-Heredia, J. Torregrosa, and J.L. Acero, Treatment of olive mill wastewaters by ozonation, aerobic degradation and the combination of both treatments, J. Chem. Technol. Biotechnol. 74 (1999), pp. 639–646. [24] T. Coskun, E. Debik, and N. Manav Demir, Treatment of olive mill wastewaters by nanofiltration and reverse osmosis membranes, Desalination 259 (2010), pp. 65–70. [25] L. Rizzo, G. Lofrano, M. Grassi, and V. Belgiorno, Pretreatment of olive mill wastewater by chitosan coagulation and advanced oxidation processes, Sep. Purif. Technol. 63 (2008), pp. 648–653. [26] E. Bettazzi, M. Morelli, S. Caffaz, C. Caretti, E. Azzari, and C. Lubello, Olive mill wastewater treatment: An experimental study, Water Sci. Technol. 54 (2006), pp. 17–25. [27] R.C. Martins, A.M.T. Silva, S. Castro-Silva, P. GarçãoNunes, and R.M. Quinta-Ferreira, Adopting strategies to improve the efficiency of ozonation in the real-scale treatment of olive oil mill wastewaters, Environ. Technol. 31 (2010), pp. 1459–1469. [28] M. Aresta, A. Dibenedetto, M. Narracci, and I. Tommasi, A technology for the treatment of olive-mill waste water in a continuously fed plant, Environ. Chem. Lett. 1 (2003), pp. 13–18. [29] M. Del Bubba, L. Checchini, C. Pifferi, L. Zanieri, and L. Lepri, Olive mill wastewater treatment by a pilot-scale subsurface horizontal flow (SSF-h) constructed wetland, Anal. Chim. 94 (2004), pp. 875–887.

[30] W. Gernjak, M.I. Maldonado, S. Malato, J. Caceres, T. Krutzler, A. Glaser, and R. Bauer, Pilot-plant treatment of olive mill wastewater (OMW) by solar TiO2 photocatalysis and solar photo-fenton, Solar Energy 77 (2004), pp. 567–572. [31] A. Kyriacou, K.E. Lasaridi, M. Kotsou, C. Balis, and G. Pilidis, Combined bioremediation and advanced oxidation of green table olive processing wastewater, Process Biochem. 40 (2005), pp. 1401–1408. [32] A. Dhouib, F. Aloui, N. Hamad, and S. Sayadi, Pilotplant treatment of olive mill wastewaters by Phanerochaete chrysosporium coupled to anaerobic digestion and ultrafiltration, Process Biochem. 41 (2006), pp. 159–167. [33] S. Khoufi, F. Feki, F. Aloui, and S. Sayadi, Pilot-plant results of the electro-fenton treatment of olive mill wastewaters followed by anaerobic digestion, Water Sci. Technol. 55 (2007), pp. 67–73. [34] S. Khoufi, F. Feki, F. Aloui, and S. Sayadi, Pilot-plant results of the electro-fenton treatment of olive mill wastewaters followed by anaerobic digestion, Water Sci. Technol. 55 (2007), pp. 259–265. [35] E. Herouvim, C.S. Akratos, A. Tekerlekopoulou, and D.V. Vayenas, Treatment of olive mill wastewater in pilot-scale vertical flow constructed wetlands, Ecol. Eng. 37 (2011), pp. 931–939. [36] D. Mantzavinos and N. Kalogerakis, Treatment of olive mill effluents part I. organic matter degradation by chemical and biological processes – an overview, Environ. Intern. 31 (2005), pp. 289–295. [37] K. Kestio˘glu, T. Yonar, and N. Azbar, Feasibility of physico-chemical treatment and advanced oxidation processes (AOPs) as a means of pretreatment of olive mill effluent (OME), Process Biochem. 40 (2005), pp. 2409–2416. [38] M. U˘gurlu and ˙I. Kula, Decolourization and removal of some organic compounds from olive mill wastewater by advanced oxidation processes and lime treatment, Environ. Sci. Pollut. Res. 1414 (2007), pp. 319–325. [39] A. Bedoui, K. Sindi, and N. Bensalah, Treatment of refractory organics contained in actual agro-industrial wastewaters by UV/H 2 O2 , Clean Soil Air Water 36 (2008), pp. 373– 379. [40] F.J. Beltran, J.F. Garcia-Araya, J. Frades, P. Alvarez, and O. Gimeno, Effects of single and combined ozonation with H 2 O2 or UV radiation the chemical degradation and biodegradability of debittering table olive industrial wastewaters, Water Res. 33 (1999), pp. 723–732. [41] P. Karageorgos, A. Coz, M. Charalabaki, N. Kalogerakis, N.P. Xekoukoulotakis, and D. Mantzavinos, Ozonation of weathered olive mill wastewaters, J. Chem. Technol. Biotechnol. 81 (2006), pp. 1570–1576. [42] T. Ölmez-Hanci, E. Dulekgurgen, ˙I. Arslan-Alaton, and D. Orhon, Effect of chemical treatment on the aromatic carbon content and particle size distribution-based organic matter profile of olive mill wastewaters, Fresenius Environ. Bull. 17 (2008), pp. 1790–1795. [43] S. Dogruel, T. Olmez-Hanci, Z. Kartal, I. Arslan-Alaton, and D. Orhon, Effect of Fenton’s oxidation on the particle size distribution of organic carbon in olive mill wastewater, Water Res. 43 (2009), pp. 3974–3983. [44] B. Kiril Mert, T. Yonar, M. Yalili Kilic, and K. Kestio˘glu, Pre-treatment studies on olive oil mill effluent using physicochemical, Fenton and Fenton-like oxidations processes, J. Hazard. Mater. 174 (2010), pp. 122–128. [45] Anonymous, Turkish Water Control Regulation, Environmental Ministry of the Turkish Republic, 2004. Available at https://www.bayindirlik.gov.tr/dosyalar/images/file/ 25687SKKY.pdf.

Downloaded by [Nipissing University] at 14:47 18 October 2014

Environmental Technology [46] I.A. Balcioglu and I. Arslan, Treatment of textile waste water by heterogeneous photocatalytic oxidation processes, Environ. Technol. 18 (1997), pp. 1053–1059. [47] N. Azbar, T. Yonar, and K. Kestioglu, Comparison of various advanced oxidation processes and chemical treatment methods for COD and color removal from a polyester and acetate fiber dyeing effluent, Chemosphere 55 (2004), pp. 35–43. [48] APHA, AWWA, WEF, Standard Methods for the Examination of Water and Wastewater, 20th Edition, American Public Health Association, Washington, DC, USA, 1998. [49] E. Oktav Akdemir and A. Ozer, Application of a statistical technique for olive oil mill wastewater treatment using ultrafiltration process, Sep. Purif. Technol. 62 (2008), pp. 222–227. [50] E. Turano, S. Curcio, M.G. De Paola, V. Calabrò, and G. Iorio, An integrated centrifugation–ultrafiltration system in the treatment of olive mill wastewater, J. Membr. Sci. 209 (2002), pp. 519–531. [51] N. Mameri, F. Halet, M. Droiche, H. Grib, A. Pauss, D. Piron, and D. Belhocine, Treatment of olive mill washing water by ultrafiltration, Can. J. Chem. Eng. 78 (2000), pp. 590– 595. [52] I. Arslan and I. Akmehmet Balcio˘glu, Oxidative treatment of simulated dyehouse effluent by UV and near-UV light assisted fenton’s reagent, Chemosphere 39 (1999), pp. 2767–2783. [53] M. Muruganandham and M. Swaminathan, Advanced oxidative decolourisation of Reactive Yellow 14 azo dye by UV/TiO2 , UV/H 2 O2 , UV/H 2 O2 /Fe2+ processes – a comparative study, Sep. Purif. Technol. 48 (2006), pp. 297–303. [54] P.T. Zayas, G. Geissler, and F. Hernandez, Chemical oxygen demand reduction in coffee wastewater through chemical flocculation and advanced oxidation processes, J. Environ. Sci. 19 (2007), pp. 300–305.

1531

[55] J.C. Garcia, J.L. Oliveira, A.E.C. Silva, C.C. Oliveira, J. Nozaki, and N.E. de Souza, Comparative study of the degradation of real textile effluents by photocatalytic reactions involving UV/TiO2 /H2 O2 and UV/Fe+2 /H2 O2 systems, J. Hazard. Mater. 147 (2007), pp. 105–110. [56] P.R. Gogate and A.B. Pandit, A review of imperative technologies for wastewater treatment II: Hybrid methods, Adv. Environ. Res. 8 (2004), pp. 553–597. [57] L.K. Weavers, I. Hua, and M.R. Hoffmann, Degradation of triethanolamine and chemical oxygen demand reduction in wastewater by photoactivated periodate, Environ. Res. 69 (1997), pp. 1112–1119. [58] J. Prado and S. Esplugas, Comparison of different advanced oxidation processes involving ozone to eliminate atrazine, Ozone Sci. Eng. 21 (1999), pp. 39–52. [59] O. Legrini, E. Oliveros, and A.M. Braun, Photochemical processes for water treatment, Chem. Rev. 93 (1993), pp. 671–698. [60] F.J. Benitez, J.L. Acero, T. Gonzalez, and J. Garcia, Organic matter removal from wastewaters of the black olive industry by chemical and biological procedures, Process Biochem. 37 (2001), pp. 257–265. [61] K. Kestio˘glu and T. Yonar, A process for olive oil mill wastewater treatment, TR 2009 08959 A2, (2009). Available at http://www.tpe.gov.tr/portal/default.jsp. [62] J.R. Bolton, K.G. Bircher, W. Tumas, and C.A. Tolman, Figures of merit for the technical development and application of advanced oxidation technologies for both electric and solar driven systems, Pure Appl. Chem. 73 (2001), pp. 627–637. [63] T. Yonar, Treatability studies on traditional hand-printed textile industry wastewaters using fenton and fenton-like processes: Plant design and cost analysis, Fresenius Environ. Bull. 19 (2010), pp. 2758–2768. [64] http://www.egeliihracatcilar.com (accessed 03.03.2012).

Pilot-scale treatment of olive oil mill wastewater by physicochemical and advanced oxidation processes.

The pilot-scale treatability of olive oil mill wastewater (OOMW) by physicochemical methods, ultrafiltration and advanced oxidation processes (AOPs) w...
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