Anaerobic acidification of a synthetic wastewater in batch reactors at 55°C

2002 ◽  
Vol 46 (11-12) ◽  
pp. 153-157 ◽  
Author(s):  
H.Q. Yu ◽  
H.H.P. Fang
Keyword(s):  
Fatty Acid ◽  
Substrate Concentration ◽  
Volatile Fatty Acid ◽  
Biomass Yield ◽  
Oxygen Demand ◽  
Dairy Wastewater ◽  
Synthetic Wastewater ◽  
Batch Reactors ◽  
Production Of Hydrogen ◽  
Anaerobic Acidification

Experiments were conducted to study the acidogenesis of a dairy wastewater in batch reactors at pH 5.5 and 55°C. There was a biased fermentation sequence for carbohydrate and protein, and the protein fermentation was delayed by carbohydrate. The production of hydrogen was exclusively from the fermentation of carbohydrate. Acetate and butyrate concentrations both increased rapidly at the beginning and peaked at some points, then declined in the reactors fed with 8 g-COD (chemical oxygen demand)/l, or higher concentrations. Butanol and propanol fractions increased with the substrate concentration. The metabolism shifted from the volatile fatty acid-producing pathways to the alcohol-producing pathways when the substrate concentration increased beyond 8 g-COD/l. The acidogenic biomass yield was in the range 0.19-0.25 mg-VSS/mg-COD.

Co-treatment of landfill leachate in laboratory-scale sequencing batch reactors: analysis of system performance and biomass activity by means of respirometric techniques

2014 ◽  
Vol 69 (6) ◽  
pp. 1267-1274 ◽  
Author(s):  
M. Capodici ◽  
D. Di Trapani ◽  
G. Viviani
Keyword(s):  
Landfill Leachate ◽  
Oxygen Uptake Rate ◽  
Oxygen Demand ◽  
Domestic Wastewater ◽  
Ammonia Nitrogen ◽  
Synthetic Wastewater ◽  
Batch Reactors ◽  
Sequencing Batch Reactors ◽  
Population Average ◽  
Biomass Activity

Aged or mature leachate, produced by old landfills, can be very refractory; for this reason mature leachate is difficult to treat alone, but it can be co-treated with sewage or domestic wastewater. The aim of the study was to investigate the feasibility of leachate co-treatment with synthetic wastewater, in terms of process performance and biomass activity, by means of respirometric techniques. Two sequencing batch reactors (SBRs), named SBR1 and SBR2, were fed with synthetic wastewater and two different percentages of landfill leachate (respectively 10% and 50% v v−1 in SBR1 and SBR2). The results showed good chemical oxygen demand (COD) removal efficiency for both reactors, with average COD removals equal to 91.64 and 89.04% respectively for SBR1 and SBR2. Furthermore, both SBRs showed good ammonia-nitrogen (AN) removal efficiencies, higher than 60%, thus confirming the feasibility of leachate co-treatment with a readily biodegradable wastewater. Significant respiration rates were obtained for the heterotrophic population (average values of maximum oxygen uptake rate equal to 37.30 and 56.68 mg O2 L−1 h−1 respectively for SBR1 and SBR2), thus suggesting the feasibility of leachate co-treatment with synthetic wastewater.

scholarly journals Acidogenesis of dairy wastewater at various pH levels

2002 ◽  
Vol 45 (10) ◽  
pp. 201-206 ◽  
Author(s):  
H.-Q. Yu ◽  
H.H.P. Fang
Keyword(s):  
Fatty Acids ◽  
Chemical Oxygen Demand ◽  
Volatile Fatty Acids ◽  
Biomass Yield ◽  
Oxygen Demand ◽  
Dairy Wastewater ◽  
Alcohol Production ◽  
Mixed Liquor ◽  
Influence Of Ph ◽  
Fatty Acids And Alcohols

Continuous experiments were conducted to study the influence of pH in the range 4.0–6.5 on the acidification of dairy wastewater at 37°C with 12 hours of hydraulic retention in an upflow reactor. Results showed that degradation of dairy pollutants increased with pH from pH 4.0 to 5.5. At pH 5.5, 95% of carbohydrate, 82% of protein and 41% of lipid were degraded. Based on chemical oxygen demand (COD), 48.4% of dairy pollutants were converted into volatile fatty acids and alcohols in the mixed liquor, 6.1% into hydrogen and methane in biogas, and the remaining 4.9% into biomass. The biomass yield at pH 5.5 was estimated as 0.32 mg-VSS/mg-COD. Further increase of pH, up to 6.5, increased degradation of carbohydrate, protein and lipid only slightly, but resulted in the lowering of overall acid and alcohol production due to their increased conversion into methane. Acetate, propionate, butyrate and ethanol are the main products of acidogenesis. Productions of propionate and ethanol were favored at pH 4.0−4.5, whereas productions of acetate and butyrate were favored at pH 6.0−6.5.

scholarly journals Pengaruh Laju Alir Terhadap COD, BOD dan VFA pada Pengolahan Limbah Cair Pabrik Kelapa Sawit (LCPKS) dalam Bioreaktor Anaerobik

2020 ◽  
Vol 4 (2) ◽  
pp. 30
Author(s):  
Elvania Br. Pandia ◽  
Hernawati Hernawati ◽  
Theresia Jari ◽  
Abdul Kahar
Keyword(s):  
Fatty Acid ◽  
Chemical Oxygen Demand ◽  
Palm Oil ◽  
Biochemical Oxygen Demand ◽  
Volatile Fatty Acid ◽  
Oxygen Demand ◽  
Palm Oil Mill Effluent ◽  
Palm Oil Mill

Limbah cair kelapa sawit atau Palm Oil Mill Effluent (POME) merupakan bahan yang dapat digunakan untuk memproduksi biogas menggunakan reaktor anaerobik. Dalam limbah cair kelapa sawit terdapat beberapa komponen penyusun yaitu Biochemical Oxygen Demand (BOD), Chemical Oxygen Demand (COD), dan Volatile Fatty Acid (VFA). Perubahan terhadap kandungan dalam limbah cair pabrik kelapa sawit (LCPKS) dipengaruhi oleh laju alir yang terjadi dalam bioreaktor anaerobik. Pada penelitian ini dilakukan variasi laju alir yaitu Q1 ambient 0 L/hari, Q2 6 L/hari, Q3 24 L/hari untuk mengetahui laju alir optimal dalam pengolahan LCPKS pada bioreaktor anaerobik. Pengamatan dilakukan secara rutin dan resirkulasi sampel POME dilakukan selama ± 6 jam/hari. Tujuan penelitian untuk mengetahui pengaruh laju alir terhadap perubahan kadar COD, BOD, dan VFA yang terkandung dalam LCPKS dengan menggunakan bioreaktor anaerobik. Hasil dari penelitian ini adalah laju alir optimal dalam penurunan kadar COD, BOD, dan VFA dalam LCPKS yaitu sebesar 24 L/menit, dimana semakin besar laju alir yang diberikan maka kadar penurunan COD dan BOD yang terkandung dalam limbah cair kelapa sawit akan semakin besar, hal tersebut juga berlaku pada pembentukan VFA pada limbah cair, hal ini disebabkan karena penambahan variasi laju alir dapat mempengaruhi proses degradasi bahan-bahan organik dalam limbah cair kelapa sawit. Kata Kunci : POME, laju alir, bioreaktor anaerobik, biogas, LCPKS.

scholarly journals Influence of Inoculum and Substrate Concentration on Anaerobic Digestion of Ocimum Sanctum (Holy Basil)

2020 ◽  
pp. 217-219
Keyword(s):  
Anaerobic Digestion ◽  
Substrate Concentration ◽  
Oxygen Demand ◽  
Ocimum Sanctum ◽  
Batch Reactors ◽  
Anaerobic Microorganisms ◽  
Volatile Solids ◽  
Degradation Rates ◽  
Holy Basil ◽  
Anaerobic System

“Anaerobic digestion is the constrained degradation of usual organic waste in the oxygen deficient environment and the existence of anaerobic microorganisms. Anaerobic digestion is accomplished by microbial diversity. “Substrate loading rate is a measure of biological conversion capacity of anaerobic system and has significant influence on the process performance. Henceforth in the current work, the outcome of different concentrations of substrate to inoculum (0.3, 0.6 and 0.9) on anaerobic digestion of Holy Basil (Ocimum sanctum) used as substrate was explored in batch reactors for 45 days along with heterogenous cowdung as Inoculum. Temperature and biogas were noted daily. “The Volatile Solids (VS), Chemical Oxygen Demand (COD), Total Kjeldhal Nitrogen (TKN) and Phosphorous were analyzed at an interval of 5 days. Though the degradation rates of various parameters showed a higher efficiency at 0.3 inoculum to “substrate concentration, the biogas generation was impending to be maximum at 0.6 among the various digesters.

pH-adjustment strategy for volatile fatty acid production from high-strength wastewater for biological nutrient removal

2014 ◽  
Vol 69 (10) ◽  
pp. 2043-2051 ◽  
Author(s):  
Li Xie ◽  
Hui Liu ◽  
Yin-guang Chen ◽  
Qi Zhou
Keyword(s):  
Fatty Acid ◽  
Chemical Oxygen Demand ◽  
Sodium Acetate ◽  
Volatile Fatty Acid ◽  
Oxygen Demand ◽  
High Strength ◽  
Thin Stillage ◽  
Ph Adjustment ◽  
Adjustment Strategy ◽  
Initial Ph

Volatile fatty acid (VFA) production from three types of high-strength organic wastewater (cassava thin stillage, starch wastewater and yellow-wine processing wastewater) were compared. The results showed that cassava thin stillage was the most suitable substrate, based on its high specific VFA production (0.68 g chemical oxygen demand (COD)/g initial soluble chemical oxygen demand (SCOD)) and yield (0.72 g COD/g SCOD) as well as low nutrient content in the substrate and fermented liquid. The acid fermented cassava thin stillage was evaluated and compared with sodium acetate in a sequencing batch reactor system. Total nitrogen removal efficiency was higher with fermented cassava thin stillage than with the sodium acetate. The effects of pH and a pH-adjustment strategy on VFA production and composition were determined using cassava thin stillage. At an initial pH range of 7–11, a relatively high VFA concentration of about 9 g COD/L was obtained. The specific VFA production (g COD/g initial SCOD) increased from 0.27 to 0.47 to 0.67 at pH 8 and from 0.26 to 0.68 to 0.81 at pH 9 (initial pH, interval pH, and constant pH adjustment, respectively). The dominant VFA species changed significantly with the increasing frequency of the pH adjustment. Further studies will examine the metabolic pathways responsible for VFA composition.

scholarly journals Colour removal and the effect of reactive dyes on acid producing anaerobic microorganisms

2011 ◽  
Vol 46 (3) ◽  
pp. 211-218 ◽  
Author(s):  
Debraj Bhattacharyya ◽  
Kripa S. Singh
Keyword(s):  
Fatty Acid ◽  
Organic Carbon ◽  
Toxic Effect ◽  
Volatile Fatty Acid ◽  
Reactive Dyes ◽  
Production Potential ◽  
Colour Removal ◽  
Anaerobic Microorganisms ◽  
Soluble Organic Carbon ◽  
Anaerobic Acidification

The cultures from a sucrose-fed anaerobic acid reactor were dosed with 0, 60, 100, 200, 400, 800 and 1,500 mg/L, of a mixture of three Procion reactive dyes, Red MX-8B, Red MX-5B and Orange MX-2R, in order to study the colour removal and the toxic effect of the dyes on anaerobic acidification of sucrose. Sucrose undergoes a possible extracellular transformation into intermediate substances before being taken up by the acidogens for volatile fatty acid (VFA) synthesis. The rate and the extent of this uptake is unaffected by the presence of dyes. The dyes, however, reduced the rate of synthesis of VFA, and considerably diminished the VFA production potential of sucrose. The acidification stopped, likely due to an inhibition caused by VFA accumulation. As a result, only 50–60% of the soluble organic carbon was utilised for VFA synthesis. The removal of colour by the unacclimated anaerobic acidogenic biomass takes place by adsorption. However, Freundlich's adsorption constants did not suggest a favourable adsorption.

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