The Characteristic of the Soluble Microbial Products from an Anaerobic Reactor at Low Temperature

2012 ◽  
Vol 518-523 ◽  
pp. 1808-1812
Author(s):  
Lei Zhang ◽  
Wei Guang Li ◽  
Duo Ying Zhang ◽  
Ke Wang ◽  
Guang Zhi Wang
Keyword(s):  
Molecular Weight ◽  
Low Temperature ◽  
Membrane Separation ◽  
Oxygen Demand ◽  
Anaerobic Treatment ◽  
Soluble Microbial Products ◽  
Anaerobic Reactors ◽  
Anaerobic Biodegradability ◽  
Microbial Products ◽  
Aerobic Biodegradability

A large amount of soluble chemical oxygen demand (COD) exists in the effluent from anaerobic treatment of wastewater at methophilic temperature, which consists of considerable portion of soluble microbial products (SMP). As the anaerobic treatment of wastewater was significantly influenced by temperature, it is great of importance to investigate the SMP from anaerobic reactors operated at low temperature in order to improve the performance. In this study, two lab-scale UASB reactors were performed to treat synthetic glucose and acetate wastewater respectively at an initial concentration of 1000 mg-COD/L at 15 °C. The SMP was found in the effluent from the glucose-fed UASB, and it was 6% of the influent COD concentration. The SMP did not accumulate in the acetate-fed UASB. The average aerobic biodegradability of the SMP was 90% and it was further enhanced by membrane separation of X100 (membrane with 100 k da molecular weight cut-offs). The anaerobic biodegradability of the SMP was 60%, and it was 100% for the fraction in which the molecular weight (MW) was lower than 10 k da. The fraction of low MW (lower than 10 k da) mainly consisted of 31.7% long chain alkanes and 13.6% esters. The aerobic polishing step is an available polishing step for the anaerobic treatment of wastewater at low temperature.

Characterization of soluble microbial products (SMP) in effluents from anaerobic reactors

2002 ◽  
Vol 45 (10) ◽  
pp. 127-132 ◽  
Author(s):  
S.F. Aquino ◽  
D.C. Stuckey
Keyword(s):  
Molecular Weight ◽  
Aromatic Compounds ◽  
Anaerobic Treatment ◽  
Soluble Microbial Products ◽  
Preliminary Results ◽  
Anaerobic Reactors ◽  
Treatment Processes ◽  
Microbial Products ◽  
Long Chain

The residual COD from anaerobic treatment processes is usually too high to comply with legislative discharge levels. It has been shown that in well operated systems the majority of the effluent COD originates from soluble microbial products (SMP) produced by the system itself, hence the characteristics of these compounds become important when assessing post-treatment systems to remove the residual COD. The molecular weight (MW) distribution and the identification of SMP in the effluents from three different anaerobic reactors will be presented. It has been found that the bulk of SMP lies in the low MW range, though compounds with MW as high as 300 kDa were also present in all anaerobic effluents. Preliminary results on the identification of such compounds using GC/MS surprisingly revealed the presence of long chain alkenes (C12–C24) and alkanes (C12–C16), as well as some aromatic compounds. These compounds that likely come from cell lysis and endogenous decay may not be easily biodegradable, hence their presence in the effluent is likely to cause the residual COD.

scholarly journals Using Molecular Weight-Based Fluorescent Detector to Characterize Dissolved EffluentOrganic Matter in Oxidation Ditch with Algae

2021 ◽  
Author(s):  
Euis Nurul Hidayah ◽  
Okik Hendriyanto Cahyonugroho ◽  
Elita Nurfitriyani Sulistyo ◽  
Nieke Karnangingroem
Keyword(s):  
Molecular Weight ◽  
Organic Matter ◽  
Humic Acid ◽  
Fulvic Acid ◽  
Average Molecular Weight ◽  
Soluble Microbial Products ◽  
Oxidation Ditch ◽  
Effluent Organic Matter ◽  
Wastewater Quality ◽  
Microbial Products

Abstract Implementation microalgae has been considered for enhancing effluent wastewater quality. However, algae can cause environmental issues due to algae released extracellular organic matter, algal organic matter, instead of bacteria-derived organic matter in the biological process. The objectives of this study are to investigate the characteristics of dissolved effluent organic matter as algal-derived organic and bacteria-derived organic during the oxidation ditch process. Experiments were conducted in the oxidation ditch without algae, with Spirulina platensis and Chlorella vulgaris. The results showed dissolved effluent organic matter increased into higher dissolved organic carbon, more aromatic and hydrophobic than that before treatment. Fluorescence spectroscopy identified two component, namely aromatic protein-like at excitation/emission 230/345 nm and soluble microbial products-like at 320/345 nm after treatment, instead of fulvic acid-like at 230/420 nm and humic acid-like at 320/420 nm in raw wastewater. Fractionation of dissolved organic fluorescence based on average molecular weight cut-offs (MWCOs) has obtained that fractions aromatic protein-like, fulvic acid-like, humic acid-like, and soluble microbial products-like has respectively a high MWCOs 50,000 Da, a high to low MWCOs <1650 Da, medium MWCOs 1650 Da to low MWCOs. Biological oxidation ditch under symbiosis algal-bacteria generated humic acid-like and fulvic acid-like with a higher MWCOs than oxidation without algal. The quality and quantity of dissolved effluent organic matter in oxidation ditch algal reactor has been significant affected by algal-bacteria symbiotic.

scholarly journals Start-up of horizontal anaerobic reactors with sludge blanket and fixed bed for wastewater treatment from coffee processing by wet method

2013 ◽  
Vol 33 (2) ◽  
pp. 353-366 ◽  
Author(s):  
Roberto A. de Oliveira ◽  
Natani M. N. Bruno
Keyword(s):  
Fixed Bed ◽  
Oxygen Demand ◽  
Anaerobic Treatment ◽  
Mean Value ◽  
Treatment System ◽  
Anaerobic Sludge ◽  
Mean Values ◽  
Anaerobic Reactors ◽  
Start Up ◽  
The Mean

In this study it was evaluated the start-up procedures of anaerobic treatment system with three horizontal anaerobic reactors (R1, R2 and R3), installed in series, with volume of 1.2 L each. R1 had sludge blanket, and R2 and R3 had half supporter of bamboo and coconut fiber, respectively. As an affluent, it was synthesized wastewater from mechanical pulping of the coffee fruit by wet method, with a mean value of total chemical oxygen demand (CODtotal) of 16,003 mg L-1. The hydraulic retention time (HRT) in each reactor was 30 h. The volumetric organic loading (VOL) applied in R1 varied from 8.9 to 25.0 g of CODtotal (L d)-1. The mean removal efficiencies of CODtotal varied from 43 to 97% in the treatment system (R1+R2+R3), stabilizing above 80% after 30 days of operation. The mean content of methane in the biogas were of 70 to 76%, the mean volumetric production was 1.7 L CH4 (L reactor d)-1 in the system, and the higher conversions were around at 0.20 L CH4 (g CODremoved)-1 in R1 and R2. The mean values of pH in the effluents ranged from 6.8 to 8.3 and the mean values of total volatile acids remained below 200 mg L-1 in the effluent of R3. The concentrations of total phenols of the affluent ranged from 45 to 278 mg L-1, and the mean removal efficiency was of 52%. The start-up of the anaerobic treatment system occurred after 30 days of operation as a result of inoculation with anaerobic sludge with active microbiota.

scholarly journals Low-temperature limitation of bioreactor sludge in anaerobic treatment of domestic wastewater

2013 ◽  
Vol 69 (5) ◽  
pp. 1004-1013 ◽  
Author(s):  
Emma J. Bowen ◽  
Jan Dolfing ◽  
Russell J. Davenport ◽  
Fiona L. Read ◽  
Thomas P. Curtis
Keyword(s):  
Low Temperature ◽  
Domestic Wastewater ◽  
Temperature Limit ◽  
Anaerobic Treatment ◽  
Anaerobic Sludge ◽  
Anaerobic Reactors ◽  
Theoretical Yield ◽  
Lower Temperature Limit ◽  
Temperature Limitation ◽  
Lower Temperature

Two strategies exist for seeding low-temperature anaerobic reactors: the use of specialist psychrophilic biomass or mesophilic bioreactor sludge acclimated to low temperature. We sought to determine the low-temperature limitation of anaerobic sludge from a bioreactor acclimated to UK temperatures (&lt;15 °C). Anaerobic incubation tests using low-strength real domestic wastewater (DWW) and various alternative soluble COD sources were conducted at 4, 8 and 15 °C; methanogenesis and acidogenesis were monitored separately. Production of methane and acetate was observed; decreasing temperature resulted in decreased yields and increased ‘start-up’ times. At 4 °C methanogenesis not hydrolysis/acidogenesis was rate-limiting. The final methane yields at 4 °C were less than 35% of the theoretical potential whilst at 8 and 15 °C more than 75 and 100% of the theoretical yield was achieved respectively. We propose that the lower temperature limit for DWW treatment with anaerobic bioreactor sludge lies between 8 and 4 °C and that 8 °C is the threshold for reliable operation.

scholarly journals Combined Effect of Colloids and SMP on Membrane Fouling in MBRs

Membranes ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 118 ◽  
Author(s):  
Dimitra Banti ◽  
Manassis Mitrakas ◽  
Georgios Fytianos ◽  
Alexandra Tsali ◽  
Petros Samaras
Keyword(s):  
Membrane Fouling ◽  
Oxygen Demand ◽  
Membrane Bioreactors ◽  
Combined Effect ◽  
Transmembrane Pressure ◽  
Soluble Microbial Products ◽  
Treatment Efficiency ◽  
Membrane Pore ◽  
Microbial Products ◽  
Membrane Pore Size

Membrane fouling investigations in membrane bioreactors (MBRs) are a top research issue. The aim of this work is to study the combined effect of colloids and soluble microbial products (SMPs) on membrane fouling. Two lab-pilot MBRs were investigated for treating two types of wastewater (wwt), synthetic and domestic. Transmembrane pressure (TMP), SMP, particle size distribution and treatment efficiency were evaluated. Chemical Oxygen Demand (COD) removal and nitrification were successful for both kinds of sewage reaching up to 95–97% and 100%, respectively. Domestic wwt presented 5.5 times more SMP proteins and 11 times more SMP carbohydrates compared to the synthetic one. In contrast, synthetic wwt had around 20% more colloids in the mixed liquor with a size lower than membrane pore size (<400 nm) than domestic. Finally, the TMP at 36 days reached 16 kPa for synthetic wwt and 11 kPa for domestic. Therefore, synthetic wwt, despite its low concentration of SMPs, caused severe membrane fouling compared to domestic, a result that is attributed to the increased concentration of colloids. Consequently, the quantity of colloids and possibly their special characteristics play decisive and more important roles in membrane fouling compared to the SMP—a novel conclusion that can be used to mitigate membranes fouling.

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