3. PROCEDIA.pdf - Acidogenesis of Palm Oil Mill Effluent to Produce Biogas: Effect of Hydraulic Retention Time and pH

  

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  Available online at www . sciencedirect.com [28] ScienceDirect ScienceDir ect Procedia - Social and Behavioral Sciences 195 ( 2015 ) 2466 – 2474 World Conference on Technology, Innovation and Entrepreneurship

  Acids of Palm Oil Mill Effluent to Produce Biogas: [22]

  Effect of Hydraulic Retention Time and pH a a a a

  Bambang Trisakti *, Veronica Manalu , Irvan Taslim , Muhammad Turmuzi a Chemical Engineering Department, University of Sumatera UtaraJalan Almamater Komplek USU, Medan 20155, Indonesia

  Abstract Abstract [23]

Acidogenesis of palm oil mill effluent to produce biogas was conducted base on anaerobic digestion process . This process was

[23] consisted of four different stages using various types of microorganisms which came from various groups of bacteria. This

research studied the effect of hydraulic retention time (HRT ) and pH to the change of the organic compounds concentration and

[29]

solids content of POME to the growth of microorganisms during acidogenesis stage. Initially, the loading up was

[23]

determined by varying the HRT 6 . 7; 5.0; and 4. 0 days in the continuous stirred tank reactor (CSTR) with mixing rate 50 rpm,

pH 6 . 0 ± 0.2, and room temperature. Next, suitable pH was determined by varying the pH at 5.0; 5.5; and 6.0 with mixing rate o

  100-110 rpm and temperature 55

  C. Analysis of TS, VS, TSS, VSS, COD, and VFA were conducted in order to study the growth

of microorganisms and their abilities in converting organic compound to produce VFA. The highest growth of microorganisms

[20] was achieved at HRT 4.0 day with microorganism concentration was 20.62 mg VSS/L and COD reduction 7%. The

[20] [20]

highest production of total VFA achieved was 5622 . 72 mg/L at pH 6 . 0, with the concentration of acetic acid , propionic acid and

butyric acid were 2257. 34; 975.49; and 2389.90 mg/L, respectively. While degradation VS and COD were 11 and 23%, respectively.

  //creativecommons.org/licenses/by-nc-nd/4.0/).

  Peer-review under responsibility of Istanbul University.

  Peer-review under responsibility of Istanbul Univeristy.

  Keywords: acidogenesis; anaerobic digestion; biogas; POME * Corresponding author. Tel.: +62-812-6362-2066; fax: +62-61-821-3250.

  E-mail address: b_trisakti@yahoo.com

  [28] Bambang Trisakti et al. / Procedia - Social and Behavioral Sciences 195 ( 2015 ) 2466 – 2474 2467

  [4 4 8]

  1. Introduction

Indonesia is currently the largest producer of palm oil in the world with a total production reached 33 million tons

  1. Introduction

  

(USDA FAS, 2015). Palm oil is produced from approximately 8.54 million hectares of oil palm plantations (Wright

& Rahmanulloh, 2015), which mostly located on the island of Sumatra and Borneo (Jaenicke et al., 2008). The

process to extract oil requires significantly large amounts of water for steam sterilization of fresh palm fruit bunches

(FFB) and clarification of extracted oil. As a result, palm oil mill (POM) produces large amounts of wastewater or

commonly called palm oil mill effluent (POME). For every ton of FFB processed will produce approximately 0.6 to

  3 0.87 m POME or 2.4 to 3.7 tons of POME per one ton of palm oil produced (Alam, Jamal, & Nadzir, 2008; O-

Thong, Boe, & Angelidaki, 2012). POM also generates large amount of solids wastes such as empty fruit bunch

(EFB) (23%), shell (5%), and mesocarp fiber (12%) for every ton of FFB processed in the mills (O-Thong, Boe, &

Angelidaki, 2012).

  

Most of the existing POME processing in POMs is anaerobic-aerobic lagoon system (Wu, Mohammad, Jahim, &

Anuar, 2010). This system aims to reduce waste pollution parameters before being disc

[17]

  [21]

for land application (Lam & Lee, 2011). POME as feedstock utilization of biogas ( CH , CO , H S , etc.) through the

  4

  2

  2

process of anaerobic digestion has been widely reported by the researchers, even has been applied on a commercial

scale in several POMs in Malaysia and Indonesia (Hosseini & Wahid, 2013). POME conversion into biogas would

provide more benefits because this process in addition will reduce waste poparameters such as organic solids,

  [20]

microbial pathogens, and toxicity. Furthermore, this technique will also produce biogas which can be used as an

  [21]

alternative energy (Stamatelatou, Antonopoulou , & Lyberatos, 2011). Although it has been applied on a commercial

scale, but the hydraulic retention time (HRT) is still hiugh so that the investment needed to build this process

  [34] is high (Yingyuad, 2007).

  

Anaerobic digestion is a biochemical process without the presence of oxygen which complex organic compounds

are broken down by different types of anaerobic bacteria (Seadi et al. , 2008). This process involves a four-step

process that engages four different types of bacterial groups (hydrolysis, acidogenic, acetogenic, and methanogenic).

  

Each of these bacteria have a different physiology and nutritional requirements (Olvera & Lopez, 2012). If all four

groups of bacteria are working under the same conditions, there will be an imbalance between the formations of acid

and methane that biogas production time will be longer (Jung et al., 2000). In an effort to accelerate the rate of

biogas production, many researchers separate the anaerobic digestion process into two stages (Jung et al., 2000). In

the first stage, the organic compounds contained in POME are converted into compounds of volatile fatty acids

(VFA) by hydrolysis, acidogenesis, and acetogenesis (commonly referred as acidogenesis stage) and subsequently

the VFA is converted into biogas through methanogenesis stage (Wong et al., 2013). Therefore, to improve the

effectiveness of the two-stage anaerobic digestion process, the optimum operating conditions such as pH,

temperature, and agitation rate of each of the stages should be known (Veeken et al., 2000; Polprasert, 2007). This

paper will report the effect of variations of HRT and pH on the acidogenesis stage.

  2. Literature Review

Indonesian palm oil production in the coming years is expected to continue to rise, as shown on Figure 1 that the

growth of the average production during the last 10 years is increasing. The high production of palm oil led to the

amount of liquid waste or POME produced is also high. It is estimated that in 2014, the number of POME generated

is about 79.2 - 122.1 million tons for every one ton of palm oil (Alam, Jamal, & Nadzir, 2008; O-Thong, Boe, &

Angelidaki 2012).

  2. Literature Review

  [24] o

  Fresh POME is a liquid brownish viscous mud with temperature around 80-90

  C, acidic (pH 3 . 8-4.5), and the

concentration of organic particles is high enough so the COD and BOD are also high (Zinatizadeh et al., 2006).

  2468 Bambang Trisakti et al. / Procedia - Social and Behavioral Sciences 195 ( 2015 ) 2466 – 2474

  

(Na), calcium (Ca), iron (Fe), zinc (Zn), chromium (Cr), and others (Salihu & Alam, 2012). Therefore, POME can

be utilized as substrates and nutrients for microorganisms in methanogenic anaerobic digestion for biogas

production (Seadi et al., 2008).

  [21]

  Fig. 1. Indonesia's palm oil production growth in 2004-2014 (Source: Wright & Rahmanulloh, 2015)

  

Methanogenic anaerobic digestion is anaerobic bioconversion process that actually has been practiced for a long

time and has also been applied on a commercial scale . This process is complicated because it involves a mixed

population of microorganisms and produces various gases and fluids, so it requires accurate process control and

product purification (Li & Yu, 2011). As a comparison, a two-stage process of anaerobic digestion, which separates

the stage acidogenesis and methanogenesis stages, is allowing for more flexible operations. Furthermore the amount

and purity of the product is higher (Blonskaja, Menert, & Vilu, 2003;. Demirer & Chen, 2005).

  Some researchers report that the methanogenesis stage takes place at a neutral pH range, with optimum ranges

between 7-8, while microorganisms acidogenesis generally are optimum at lower pH (Seadi et al., 2008).

Environmental factors that influence the acidogenesis stages are substrate, inoculum, pH, temperature, and HRT (He

et al., 2012). Low pH and short HRT are conditions favored by acid-forming bacteria to grow and may inhibit the

  [18]

growth of microorganisms forming methane (Solera, Romero, & Sales, 2002). High alkalinity is often necessary to

maintain the pH in connection with high CO content in the biogas (Zhang, 2014).

2 Control of HRT is needed to help multiply the microorganisms of hydrolysis and acidogenesis (Fang and Yu,

  [49]

2000) and will increase the production of VFA (Maharaj & Elefsiniotis, 2001). Retention time should be long

enough to ensure the number of dead microorganisms in the digester is not higher than the amount of reproduced

microorganisms (Seadi et al. , 2008)

  3. Methodology

  3. Methodology

3.1. Research Goal

  

This paper reports the effect of loading up (variations HRT) and pH variations of acidogenesis stage or first stage

   Bambang Trisakti et al. / Procedia - Social and Behavioral Sciences 195 ( 2015 ) 2466 – 2474 2469 [27]

3.2. Materials, Experimental set-up, and Data Collection

  Materials x

Fresh POME was collected from a fat pit of Adolina POM, Sumatera Utara, Indonesia, and stored in 300 L clean

high-density polyethylene (HDPE) container. It was transported to the laboratory, mixed well, 1-liter plastic

  [54]

bottles, and stored at 4 °C until further use. Fresh POME characteristics are shown in Table 1 . Acidogenic bacteria

as starter were collected from acidification pond of WWTP of POM at Torgamba, Sumatera Utara, Indonesia.

  Sodium bicarbonate (NaHCO 3 ) was used as pH adjusting.

  Table 1. Characteristics of fresh POME Parameters Units Results Methods

  • pH 3.70 – 4.70 Chemical Oxygen Demand (COD) mg/L 48,300 APHA 5220B Total Solid (TS) mg/L 13,420 – 37,020 APHA 2540B Volatile Solid (VS) mg/L 10,520 – 31,220 APHA 2540E Total Suspended Solid (TSS) mg/L 2,080 – 27,040 APHA 2540D Volatile Suspended Solid (VSS) mg/L 1,920 – 25,800 APHA 2540E

  Oil and Grease mg/L

  6.25 APHA 5520B [23] Protein % 0.

  53 Kjeldahl Carbohydrate % trace Lane Eynon Experimental set-up x

The laboratory scale of continuous stirred tank reactor (CSTR) as fermenter is shown in Figure 2. The CSTR is

  

EYELA model MBF 300ME with working volumes is 2 L. The fermenter comprises an integrated on-line

temperature and pH data recording system. No pH adjustment was applied to the fermenter. However, pH of the raw

POME was controlled with sodium bicarbonate (NaHCO ), then after that, fed into the fermenter.

  3 Figure 2. Experimental set-up

  2470 Bambang Trisakti et al. / Procedia - Social and Behavioral Sciences 195 ( 2015 ) 2466 – 2474

  Data Collection x

Data collected during the experiment were pH, alkalinity, TS, VS, TSS, VSS, COD, and VFA which according to

the American Public Health and Association (APHA) standard methods for water and wastewater (APHA, 1999) as

presented in Table 2.

  Table 2. Analysis methods of data collection (APHA, 1999) Parameters Units Methods

  • pH Alkalinity mg/L APHA 2320B Total Solid (TS) mg/L APHA 2540B Volatile Solid (VS) mg/L APHA 2540E Total Suspended Solid (TSS) mg/L APHA 2540D Volatile Suspended Solid (VSS) mg/L APHA 2540E

  Chemical Oxygen Demand (COD) mg/L APHA 5220B Volatile Fatty Acids (VFA) mg/L APHA 5560B

  3.3. Results and Discussion Effect of hydraulics retention time (HRT) x

Microbial adaptation and growth of the starter were carried out by reducing the HRT or organic loading up.

  

During loading up, HRT was reduced slowly and evaluated at HRT 6.7; 5.0; and 4.0 days. The fermenter was

controlled at room temperature, mixing rate 50 rpm, and the pH was kept constant at 6 (± 0.2). The experiment was

conducted in intermittent operation mode, where fresh feed and effluent where flown in every 4 hours or 6 times per

24 hours. pH was maintained by adding sodium bicarbonate (NaHCO ) in the fresh feed. pH, alkalinity, TS, and VS

  3

of the feed and effluent were analyzed every day, while the TSS, VSS, COD and VFA were analyzed after the stable

data was achieved. The results of experiments on organic loading up are presented in a graph showing the effect of

HRT reduction on pH and alkalinity, also the microbial growth, and COD reduction.

  

The effect of HRT reduction on pH and alkalinity is presented in Figure 3. The pH value slightly fluctuates but

remains constant at 6 days because the addition of sodium bicarbonate in the feed. As a result, large fluctuation in

the value of alkalinity occurred, although it is still in the range where the acidogenesis process takes place i.e. in the

range of 542 - 3580 mg/L (Senthil Kumar 2010; Schmit & Ellis, 2001)

  Alkalinity range

   Bambang Trisakti et al. / Procedia - Social and Behavioral Sciences 195 ( 2015 ) 2466 – 2474 2471

Effect of HRT reduction on microbial growth is described by the change of VSS concentration in the fermenter.

  

Metabolism and growth of microbial are also highly dependent on the pH and alkalinity (SenthilKumar 2010;

Schmit & Ellis, 2001). Figure 4 shows VSS profile simultaneously with the pH and alkalinity during the process.

The pattern of microbial growth is significantly influenced by changes in pH and alkalinity. The highest

concentration of microbes achieved at HRT 4 days was 20.62 mg VSS/L, although at this is the shortest HRT.

  Figure 4. Effect of HRT reduction on microbial growth

  

Effect of reduction HRT on microbial growth can also be explained by the amount of COD decrease in inlet and

outlet of the fermenter as shown in Figure 4. Although the decrease of COD indicates the occurrence of microbial growth but the expected decrease COD is not too large, because the desired product of acidogenesis process is VFA.

  Figure 5. Effect of reduction of HRT on COD reduction

  Effect of pH x

Effect of pH on acidogenesis process was studied by conducting a series of experiments by varying the pH at 5.0;

  5.5; and 6.0, mixing rate at 100 rpm, temperature of 55 °C, and HRT 4 days. The experiment was conducted in

intermittent operation mode, where fresh feed and effluent where flown in every 4 hours or 6 times per 24 hours.

The pH was maintained by adding sodium bicarbonate (NaHCO ) in the feed. The pH, alkalinity, TS, and VS from

  3

  2472 Bambang Trisakti et al. / Procedia - Social and Behavioral Sciences 195 ( 2015 ) 2466 – 2474

  

Effect of pH on alkalinity and microbial growth are presented in Figure 6. At the beginning of pH 5.0 the

alkalinity is decreased, because the pH of fresh POME is 4.7 and thus the addition of sodium bicarbonate in feed is

only small. After day 10, alkalinity started to rise and eventually fluctuated at 3000 mg/L. Similarly, the growth of

microbes, although initially decreased but from day 10 to be stable in the range of 12000-16000 mg/L.

  a b

  Figure 6. Effect of pH on (a) alkalinity and (b) microbial growth

  

Effect of pH on VS and COD reduction is presented in Figure 7. Both graphs are actually used to look for

microbial activity. VS and COD reduction is best achieved at a pH of 5.5 for the redu ction is not too large.

  a b

  Figure 7. Effect of pH on (a) VS reduction and (b) COD reduction

  Effect of pH on VFA production is presented in Figure 8 (a) while its effect on the VFA alkalinity ratio is

presented in Figure 8 (b). VFA production is expressed with the production of acetic acid, propionic acid, and

[40]

butyric acid. Although the VFA production was highest at pH 5. 0, but high production of propionic acid, if the

unt is greater than 1500 mg/L, its presence will disrupt next stage (methanogenesis) (Senthilkumar et al . , 2010).

  [40]

Thus, the highest VFA production are at pH 6 but considering the VS and COD reduction (Figure 7), then the VFA

production is best at pH 5.

  5. The VFA alkalinity ratio (Figure 8b) is to describe the stability of process acidogenesis where it is assumed stable if the VFA alkalinity ratio is greater than one (Li et al., 2012).

   Bambang Trisakti et al. / Procedia - Social and Behavioral Sciences 195 ( 2015 ) 2466 – 2474 2473

  a b

  Figure 8. Effect of pH on (a) VFA production and (b) VFA Alkalinity ratio 4.

4. Conclusion Conclusion

  

On the loading up process, the highest growth of microorganisms was achieved at HRT 4.0 day with

[20] microorganism concentration was 20.62 mg VSS/L and COD reduction was 15.7%. Meanwhile, on the pH variation, the highest production of total VFA achieved was 5622 . 72 mg/L at pH 6.0, with the concentration of acetic acid, propionic acid and butyric acid were 2257.34; 975.49; and 2389.90 mg/L, respectively. While degradation VS and COD were 11 and 23%, respectively.

  Acknowledgements Acknowledgements This research was supported by Penelitian Desertasi Doktor No. 4800/UN5.1.R/KEU/2014, date June 23, 2014. References References USDA FAS. (2015). Oilseeds: Markets and Trade. April 2015. (pp. 16). (http://apps.fas.usda.gov/psdonline/circulars/oilseeds.pdf).

  Wright, T., & Rahmanulloh, A. (2015). Oilseeds and Products: Annual Report 2015. GAIN Report. (pp. 2-4). Jakarta: USDA Foreign Agricultural Service. Jaenicke, J., Rieley, J.O., Mott, C., Kim man, P., & Siegert, F. (2008). Determination of the amount of carbon stored in Indonesian peatlands.

  Journal Geoderma, 147, 151–158 . [24] [24]

  Alam, M. Z., Jamal, P., & Nadzir, M. M. (2008). Bioconversion o f palm oil mill effluent for citric acid production : statistical optimization of fermentation media and time by central composite design . World J Microbiol Biotechnology, 24, 1177–1185. O-Thong, S., Boe, K., & Angelidaki, I. (2012). Thermophilic Anaerobic Co-digestion of Oil palm Empty Fruit Bunches with Palm Oil Mill Effluent for Efficient Biogas Production, Journal Applied Energy, 93, 648-654. [19] Wu, T. Y., Mohammad, A. W., Jahim, J. Md., & Anuar N. (2010). Pollution control tegement , 91, 1467-1490. [19] [33]

  Lam, M.K., & Lee K.T. (2011). Renewable and sustainable bioenergies production from palm oil mill effluent (POME ): Win–win strategies toward better environmental protection . Journal Biotechnology Advances, 29, 124– [18] [19] Hosseini, S.E., & Wahid, M.A. (2013). Feasibility study of biogas production and utilization as a source of renewable energy in Malaysia .

  Journal Renewable and Sustainable Energy Reviews , 19, 454–462.

  Stamatelatou, K., Antonopoulou, G., & Lyberatos, G. (2011). Production of Biogas Via Anaerobic Digestion. Greece: Woodhead. Yingyuad, R. (2007). Selection of Biogas Production System for Tapioca Starch Wastewater by Using Analytic Hierarchy Process. Thailand: Shinawatra University. [34]

  Seadi, T.A., Rutz, D., Prassl, H., Kottner, M., Finsterwalder, T., Volk, S., & Janssen, R. (2008). Biogas Handbook. Esbjerg: University of Southern Denmark . Olvera, J.R., & Lopez, A.L (2012). Biogas Production from Anaerobic Treatment of Agro-Industrial Wastewater. Rijeka: Intech. Jung, J.Y., Lee, S.M., Shin, P.K., Chung, Y.C. (2000). Effect of pH on Phase Separated Anaerobic Digestion. Biotechnology Bioprocess Engineering, 5, 456-459. [31]

  Wong, Yee Shian., Teng, T.T., Ong, Soon-An., Norhashimah, M., Rafatulloh, M., & Lee, Hong-Chen. (2013). Anaerobic acidogenesis [36]

  2474 Bambang Trisakti et al. / Procedia - Social and Behavioral Sciences 195 ( 2015 ) 2466 – 2474 [42] Veeken, A., Kalyuzhnyi, S., Scharff, H., Hamelers, B. (2000). Effect of pH and VFA on Hydrolysis of Organic Solid Waste. Journal of Environmental Engineering, 126 , 1076 – 1081. Polprasert, Chongrak. (2007). Organic Waste – Recycling. London: Iwa Publishing. Zinatizadeh, A.A.L., Mohamed, A.R., Najafpour, G.D., Isa, M.H., Nasrollahzadeh, H. (2006). Kinetic Evaluation of Palm Oil Mill Effluent Digestion in a High Rate Up-flow Anaerobic Sludge Fixed Film Bioaterial?. Journal of Applied Sciences Research, 8, 466-473. [50] Li, W-W., & Yu, H-Q. (2011). From wastewater to bioenergy and biochemicals via two-stage bioconversion processes : A future paradigm.

  Biotechnology Advances, 29, 972–982.

  Blonskaja, V., Menert, A., & Vilu, R. (2003). Use of two-stage anaerobic treatment for distillery waste. Advances in Environmental Research, 7, 671–678. Demirer, G.N., & Chen, S. (2005). Two-phase anaerobic digestion of unscreened dairy manure. Process Biochemistry. 40, 3542–3549. He, M., Sun, Y., Zou, D., Yuan, H., Zhu, B., Li, X., & Pang, Y. (2012). 㻌 Influence of temperature on hydrolysis acidification of food waste.

  Procedia Environmental Sciences, 16, 85 – 94. [47] Solera, R., Romero, L.I., & Sales, D. (2002). The Evolution of Biomass in a Two-Phase Anaerobic Treatment Process During Start-up . Biochemical Engineering, 16, 25–29.

  Zhang, X.J. (2014). Anaerobic Process.United State: University of Massachusetts Lowell. [42] Fang, H.H.P. & Yu, H.Q. (2000). Effect of HRT on Mesophilic Acidogenesis of Dairy Wastewater. Journal of Environmental Engineering , 1145–1148.

  Maharaj, I., & Elefsiniotis, P. (2001). The Role of HRT and Low Temperature on The Acid –Phase Anaerobic Digestion of Municipal and Industrial Wastewaters. Bioresources Technology, 76, 191–197. SenthilKumar, M., Gnanapragasam, G., Arutchelvan, V., & Nagarajan, S. (2010). Influence of Hydraulic Retention Time in a Two-phase Upflow

  Anaerobic Sludge Blanket Reactor Treating Textile Dyeing Effluent Using Sago Effluent as the Co-substrate. Environ. Sci. Pollut. Res. 18, 649-654. [17] APHA. (1999). Standard Methods for the Examination of Water and Wastewater . 20th edition. Washington DC: APHA, AWWA, WEF Schmit, K.H. & Ellis, T.G. (2001). Comparison of Temprature-Phased and Two-Phase Anaerobic Co-Digestion of Primary Sludge and Municipal Solid Waste. Water Environment Research. 73, 314-321. [55] Li, J., Ban, Q., Zhang, L., & Kumar, JA. (2012), Syntrophic Propionate Degradation in Anaeoric Digestion: A Review. International Journal of Agriculture and Biology , 14(5), 844-846.