Evaluation of Aerobic and Anaerobic Co-Digestion of Tetraselmis suecica and Oil Palm Empty Fruit Bunches by Response Surface Methodology

2014 ◽  
Vol 925 ◽  
pp. 243-247 ◽  
Author(s):  
Ashfaq Ahmad ◽  
Syed Muhammad Usman Shah ◽  
Azizul Buang ◽  
Mohd Fariduddin Othman ◽  
Mohd Azmuddin Abdullah

This study investigated co-cultivation of Tetraselmis suecica microalgae with Oil Palm empty fruit bunch (OPEFB) for anaerobic biomethane production and Palm oil mill effluent (POME) treatment. The highest specific biogas production (0.1162 m3 kg-1 COD day-1) and biomethane yield (3900.8 mL CH4 L-1 POME day-1) was achieved with microalgae at 2 mL mL-1 POME, and OPEFB at 0.12 g mL-1 POME. Without co-digestion of microalgae, higher specific biogas production (0.1269 m3 kg-1 COD day-1) but lower biomethane yield (3641.8 mL CH4 L-1 POME day-1) were observed. Second order polynomial model fits the data well with less than 5% error. Higher removal efficiency (62-95%) of COD, BOD, TOC and TN were achieved by aerobic and anaerobic treatment of POME with microalgae than without microalgal treatment after 3 and 7 days of hydraulic retention time (HRT).

2016 ◽  
Vol 78 (5-6) ◽  
Author(s):  
Ashfaq Ahmad ◽  
Syed Muhammad Usman Shah ◽  
Azizul Buang ◽  
Mohd Azmuddin Abdullah

This study investigated the optimization of anaerobic co-cultivation of multi-algal species with Oil Palm Empty Fruit Bunches (OPEFB) for Palm Oil Mill Effluent (POME) treatment and biomethane production. The highest removal of COD (95-98%), BOD (90-98%), TOC (81-86%) and TN (78-80%) were achieved after 7 days anaerobic treatment with the presence of microalgae. The highest biomethane (4,651.9 mL CH4/L POME/day) and the specific biogas production rate (0.124 m3/kg COD/day) with CO2 (2,265.9mL CO2/L POME/day) were achieved by co-cultivating N. oculata and Chlorella sp. (each at 1 mL/mL POME) with OPEFB (0.12 g/mL POME). The combination of N. oculata (2 mL/mL POME) with T. suecica or Chlorella sp. (each at 1 mL/mL POME), and OPEFB (0.12 g/mL POME) obtained high biomethane (4,018.9 mL CH4/L POME /day) but lower biogas (0.097 m3/kg COD/day) and CO2 (2,079.5mL CO2/L POME/day). Generally, low OPEFB and having all the three strains or increasing the level of any (2 mL/mL POME) especially T. suecica, could lower biomethane (870-953 mL CH4/L POME/day) and CO2 (803-854mL CO2/L POME/day), with the biogas around 0.08-0.09 m3/kg COD/day. The optimum conditions were predicted by Response Surface Methodology and the multiple coefficients of determination, r2, of 86% suggests good agreement between experimental and predicted values.


2014 ◽  
Vol 625 ◽  
pp. 818-821 ◽  
Author(s):  
Ashfaq Ahmad ◽  
Syed Muhammad Usman Shah ◽  
Mohd Fariduddin Othman ◽  
Mohd Azmuddin Abdullah

Co-cultivation ofNannochloropsisoculatawith Oil Palm Empty Fruit Bunches (OPEFB) was explored for biomethane production and POME treatment. The experimental results were analyzed and modeled using a multilevel factorial design (MFD) of response surface methodology (RSM). Maximum specific biogas production rate (0.126 m3kg-1COD day-1) and biomethane production (4813.0 mL CH4L-1POME day-1) were achieved with 2 mL mL-1POME of microalgae and OPEFB 0.12 g mL-1POME. POME treatment after 3 and 7 days with microalgae achieved higher removal efficiency (56-98%) of COD, BOD and TOC, than without microalgae.


2020 ◽  
Vol 5 (2) ◽  
pp. 210-216
Author(s):  
Atmadian Pratama ◽  
Ramayanty Bulan ◽  
Darwin Darwin

Abstrak. Pemanfaatan limbah peternakan sapi (kotoran sapi) sebagai sumber bahan bakar dalam bentuk biogas merupakan salah satu alternatif yang sangat tepat untuk meningkatkan nilai tambah bagi masyarakat petani. Pemanfaatan kotoran ternak sebagai sumber energi, tidak mengurangi jumlah pupuk organik yang bersumber dari kotoran ternak. Hal ini karena pada pembuatan biogas kotoran ternak yang sudah diproses dikembalikan ke kondisi semula yang diambil hanya gas metana (CH4) yang digunakan sebagai bahan bakar. Kotoran ternak yang sudah diproses pada pembuatan biogas dipindahkan ke tempat lebih kering, dan bila sudah kering dapat disimpan dalam karung untuk penggunaan selanjutnya sebagai pupuk organik. Tandan kosong sawit (TKS) merupakan limbah dari pabrik kelapa sawit yang pemanfaatnya masih terbatas sebagai pupuk organik yang memiliki nilai tambah yang rendah. Setiap produksi kelapa sawit menghasilkan limbah berupa tandan kosong sawit  sebesar 23%, sehingga berdasarkan produksi kelapa sawit tahun 2010 dan 2011 berpotensi dihasilkan limbah tandan kosong sawit sebesar 5 juta ton. Akumulasi limbah TKS dari tahun ke tahun jika tidak dimanfaatkan secara optimal maka dapat berakibat buruk bagi lingkungan. Penelitian ini bertujuan untuk melihat potensi produksi biogas melalui teknologi anaerobik digesi (anaerobic digestion) kotoran sapi dan anaerobik co-digesi kotoran sapi dengan limbah TKS. Hasil penelitian menunjukkan bahwa pada proses fermentasi dengan hydraulic retention time (HRT) 25 hari dan pemberian suhu panas yang sama terdapat hasil yang berbeda terhadap produksi biogas kotoran sapi digesi dan juga kotoran sapi co-digesi dengan tepung TKS dengan hasil produksi biogas total lebih tinggi pada fermentasi co-digesi, dimana produksi gas yang dihasilkan adalah 1.015 mL pada kotoran sapi digesi dan 13.830  mL pada kotoran sapi co-digesi. Penambahan tepung TKS meningkatkan nutrisi substrat yang dimanfaatkan mikroba untuk menghasilkan gas metan, namun tetap memperhatikan tingkat ke optimuman derajat keasaman (pH) pada angka 6,8-7,5.Production of Biogas from Cattle Manure Digestion and Co-Digestion with Oil Palm Empty Fruit Bunch under Digestive Anaerobic MethodAbstract. Utilization of livestock waste (manure) as biogas is one of the most appropriate alternatives to overcome the rising prices of fertilizers and fuel oil scarcity. The use of livestock manure as an energy source, does not reduce the amount of organic fertilizer that comes from livestock manure. This is because in the production of biogas manure that has been processed is returned to its original condition, only methane (CH4) is used as fuel. Livestock manure that has been processed in the making of biogas is moved to a drier place, and when it is dry it can be stored in a sack for further use as fertilizer. Oil palm empty fruit bunches (TKS) are waste from palm oil mills is still limited use as organic fertilizer and has low added value. Each palm oil production produces waste in the form of 23% oil palm empty fruit bunches, so that according to the palm production on 2010 and 2011, the potential production of this waste could reach 5 million tons. The accumulation of this waste from year to year will harm our environment. This study aims to look at the potential for biogas production from cow manure digestion and co-digestion with palm oil fruit bunch waste under the anaerobic process. Results showed that for 25 days hydraulic retention time (HRT) and the use of mesophilic temperature, the biogas production by using anaerobic co-digestion of cow manure with TKS (13,830 mL) was higher than the biogas production by using the anaerobic digestion of cow manure (1,015 mL). The addition of TKS flour had increased the nutrient of substrate used by microbes to produce methane gas, but the acidity (pH)of substrate should be controlled at 6.8-7.5.  


Processes ◽  
2021 ◽  
Vol 9 (5) ◽  
pp. 878
Author(s):  
Apinya Singkhala ◽  
Chonticha Mamimin ◽  
Alissara Reungsang ◽  
Sompong O-Thong

A sudden pH drops always inhibits the anaerobic digestion (AD) reactor for biogas production from palm oil mill effluent (POME). The pH adjustment of POME by oil palm ash addition and the biogas effluent recycling effect on the preventing of pH drop and change of the archaea community was investigated. The pH adjustment of POME to 7.5 increased the methane yield two times more than raw POME (pH 4.3). The optimal dose for pH adjustment by oil palm ash addition was 5% w/v with a methane yield of 440 mL-CH4/gVS. The optimal dose for pH adjustment by biogas effluent recycling was 20% v/v with a methane yield of 351 mL-CH4/gVS. Methane production from POME in a continuous reactor with pH adjustment by 5% w/v oil palm ash and 20% v/v biogas effluent recycling was 19.1 ± 0.25 and 13.8 ± 0.3 m3 CH4/m3-POME, respectively. The pH adjustment by oil palm ash enhanced methane production for the long-term operation with the stability of pH, alkalinity, and archaea community. Oil palm ash increased the number of Methanosarcina mazei and Methanothermobacter defluvii. Oil palm ash is a cost-effective alkali material as a source of buffer and trace metals for preventing the pH drop and the increased methanogen population in the AD process.


2020 ◽  
Vol 10 (1) ◽  
pp. 11-16
Author(s):  
Laily Isna Ramadhani ◽  
Sri Ismiyati Damayanti ◽  
Hanifrahmawan Sudibyo ◽  
Muhammad Mufti Azis ◽  
Wiratni Budhijanto

Indonesia is currently the most significant crude palm oil (CPO) producer in the world. In the production ofCPO, 0.7m3 of Palm Oil Mill Effluent (POME) is emitted as the wastewater for every ton of fresh fruit bunches processed in the palm oil mill.With the increasing amount of CPO production, an effective POME treatment system is urgently required to prevent severe environmental damage. The high organic content in the POME is a potential substrate forbio-methane production. The biomethane production is carried out by two groups of microbes, i.e., acidogenic and methanogenic microbes. Each group of bacteria performs optimally at different optimum conditions. To optimize the biomethane production, POME was treated sequentially by separating the acidogenic and methanogenic microbes into two stages of anaerobic fluidized bed reactors (AFBR). The steps were optimized differently according to the favorable conditions of each group of bacteria. Although perfect separation cannot be achieved, this study showed that pH control could split the domination of the bacteria, i.e., the first stage (maintained at pH 4-5) was dominated by the acidogenic microbes and the second stage (kept neutral) was governed by methanogens. In addition to the pH control, natural zeolitewas added as microbial immobilization media in the AFBR to improve the performance of the microorganisms, especially in preventing microbial wash out at short hydraulic retention time (HRT). This study was focused on the understanding of the effect of HRT on the performance of steady-state continuous AFBR. The first stage as the acidogenic reactorwas rununder acidic conditions (pH 4-5) at five different HRTs. In comparison, the second stage as the methanogenic reactorwasrun under the neutral condition at four different HRTs. In this work,short HRT (5 days) resulted in better performance in both acidogenic AFBR and methanogenic AFBR. The immobilization media was hence essential to reduce the risk of washout at such a short HRT. The two-stage system also resulted in quite a high percentage of soluble chemical oxygen demand (sCOD) removal, which was as much as 96.06%sCOD.


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