Anaerobic biodegradation of 2,4,6-trichlorophenol by methanogenic granular sludge: role of co-substrates and methanogenic inhibition

2009 ◽  
Vol 59 (7) ◽  
pp. 1449-1456 ◽  
Author(s):  
D. Puyol ◽  
A. F. Mohedano ◽  
J. L. Sanz ◽  
J. J. Rodríguez
Keyword(s):  
Volatile Fatty Acids ◽  
Removal Rate ◽  
Granular Sludge ◽  
Anaerobic Biodegradation ◽  
Methanogenic Activity ◽  
The Third ◽  
Specific Methanogenic Activity ◽  
Methanol Yeast ◽  
Complete Dechlorination

The influence of several co-substrates in the anaerobic biodegradation of 2,4,6-trichlorophenol (246TCP) by methanogenic granular sludge as well as in methanogenesis inhibition by 246TCP has been studied. 4 g-COD·L−1 of lactate, sucrose, volatile fatty acids (VFA) acetate:propionate:butyrate 1:1:1, ethanol, methanol, yeast extract (YE), and 2 g-COD·L−1 of formate and methylamine were tested. Two concentrations of 246TCP: 80 mg·L−1 and 113 mg·L−1 (this last corresponding to the EC50 for acetotrophic methanogenesis) were tested. Three consecutive co-substrate and nutrient feedings were accomplished. 246TCP was added in the second feed, and the 246TCP removal rate increased considerably after the third feed. Accumulated metabolites after ortho-dechlorination, either 4-chlorophenol (4CP) (when methanol, ethanol or VFA were used as co-substrates) or 2,4-dichlorophenol (24DCP) (with lactate) avoided the complete dechlorination of 246TCP. With methylamine and formate this compound was degraded only partially. Monochlorophenols biodegradation was partially achieved with YE, but both 24DCP and 2,6-dichlorophenol (26DCP) were accumulated. In the presence of sucrose para-dechlorination was observed. 246TCP was better tolerated by methanogens when ethanol and methanol were added because of the highest specific methanogenic activity achieved with these co-substrates. Methanol and ethanol were the best co-substrates in the anaerobic biodegradation of 246TCP.

The effect of extreme temperatures (70–80°C) on the effluent quality and sludge characteristics of UASB reactors

1997 ◽  
Vol 36 (6-7) ◽  
pp. 325-332 ◽  
Author(s):  
Raghida Lepistö ◽  
Jukka Rintala
Keyword(s):  
Volatile Fatty Acids ◽  
Granular Sludge ◽  
Anaerobic Sludge ◽  
Methanogenic Activity ◽  
Sludge Characteristics ◽  
Effluent Quality ◽  
Start Up ◽  
Thermomechanical Pulping ◽  
Increasing Temperature ◽  
Uasb Reactors

The study focused on the effluent quality and sludge characteristics during the start-up and operation of extreme thermophilic (70 to 80°C) upflow anaerobic sludge bed (UASB) reactors, inoculated with mesophilic and thermophilic granular sludge and fed with acetate, volatile fatty acids (VFA), and thermomechanical pulping (TMP) whitewater. Low effluent quality and long start-up periods were observed during the start-up of the 70 to 76°C, VFA-fed UASB reactors inoculated with mesophilic granulae, while better effluent quality and considerably shorter start-up periods were observed when thermophilic (55/70°C) inocula were used. With VFA feed, a significant amount of acetate was removed at 70°C and even at 80°C, while propionate removal was negligible. With TMP whitewater feed, low VFA effluent concentration was obtained at 70°C. The volatile solids (VS) and the VS/total solids (TS) content of the sludge decreased significantly during the first 2–3 months of operation when mesophilic inocula were used. The initial specific methanogenic activity (ISMA) of the extreme thermophilic sludge decreased with increasing temperature and was slightly higher on glucose than on acetate. At 70 to 80°C, various rod-like bacteria were dispersed through the granulae in either individual or in low density micro colonies surrounded with a varying degree of precipitates.

Effect of Low Concentration Cyanide on Startup of Expanded Granular Sludge Bed for the Treatment of Tapioca Starch Wastewater

2012 ◽  
Vol 518-523 ◽  
pp. 2493-2499 ◽  
Author(s):  
Ling Kui Zhao ◽  
Xiao Ming Li ◽  
Chuang Rong Mo ◽  
Chao Lan Zhang ◽  
Wen Cui ◽  
...  
Keyword(s):  
Volatile Fatty Acids ◽  
Anaerobic Bacteria ◽  
Oxygen Demand ◽  
Granular Sludge ◽  
Tapioca Starch ◽  
Methanogenic Activity ◽  
Cyanide Concentration ◽  
Low Concentration ◽  
A Value ◽  
Starch Wastewater

In this investigation, An Expanded Granular Sludge Bed (EGSB) was used to treat tapioca starch wastewater containing low concentration cyanide and the influence of cyanide concentration on the startup of EGSB reactor was conducted. On the condition of 13.4h of HRT, the chemical oxygen demand (COD) and cyanide concentration varied, The EGSB performance was assessed in terms of COD, pH, alkalinity, volatile fatty acids (VFA) and methane variation during the process. The results showed that cyanide was harmful to the anaerobic bacteria of the granular sludge in EGSB reactor for the treatment of tapioca starch waster, as the cyanide concentration was at 15mg/L, COD removal efficiency for cyanide free wastewater nearly 90%, however the efficient dropped to 80% with increasing cyanide concentration up to15mg/L; the methane production was nearly 200mg/L with cyanide concentration and dropped to a value of 2mg/L for 15 mg/L cyanide; and methanogenic activity decreased; while the influent VFA was increased, at an cyanide concentration of 0 and 5mg/L, the concentration of VFA was maintained below 100.00mg/L, but it was higher than 600mg/L in most of the cases with influent cyanide concentration of 15mg/L; SEM observation of the granules showed the predominance of Methanosaeta. sp. and the obvious damage of the bacteria located on the surface or in the inner part of some granules, leading to a deterioration of granular sludge settling velocity, and even some granules washed out.

Hybrid reactor performance in pentachlorophenol (pcp) removal by anaerobic granules

2001 ◽  
Vol 44 (4) ◽  
pp. 137-144 ◽  
Author(s):  
M. De Almeida Prado Montenegro ◽  
E. De Mattos Moraes ◽  
H. Moreira Soares ◽  
R. Filomena Vazoller
Keyword(s):  
Fatty Acids ◽  
Volatile Fatty Acids ◽  
Culture Media ◽  
Biogas Production ◽  
Removal Rate ◽  
Oxygen Demand ◽  
Granular Sludge ◽  
Concentration Addition ◽  
Hybrid Reactor ◽  
Reactor Performance

The present research aimed at evaluating pentachlorophenol (PCP) degradation in a hybrid reactor supplied with a mixture of fatty acids (propionic, butyric, acetic and lactic) and methanol. The performance of the reactor is remarkably stable and efficient during PCP additions at range of 2.0 to 21.0 mg/L. The reduction of chemical oxygen demand (COD) was around 97% and methane was found to be 86% in the biogas production. The efficiency of volatile fatty acids breakdown was 93%, 64% and 74% respectively for butyric, propionic and acetic. PCP total removal of more than 99% was reached by granular sludge activities formed during 21 months of reactor operation. Methanogenic microorganisms predominance was noticed with 105 to 106 cells/mL during enumeration on methanol or lactate added to sulfate culture media. The removal rate was 1.07 mg PCP · g−1 VS · d−1 during the highest PCP concentration addition.

Effect of humic acid in leachate on specific methanogenic activity of anaerobic granular sludge

2015 ◽  
Vol 36 (21) ◽  
pp. 2740-2745 ◽  
Author(s):  
Mengfei Guo ◽  
Ping Xian ◽  
Longhui Yang ◽  
Xi Liu ◽  
Longhui Zhan ◽  
...  
Keyword(s):  
Humic Acid ◽  
Granular Sludge ◽  
Anaerobic Granular Sludge ◽  
Methanogenic Activity ◽  
Specific Methanogenic Activity

scholarly journals Inhibition and anaerobic biodegradation of benz[a]anthracene-7,12- dione via the specific methanogenic activity test

2013 ◽  
Vol 2 (1) ◽  
pp. 8 ◽  
Author(s):  
FazelMohammadi Moghadam ◽  
MohammadMehdi Amin ◽  
MehdiHajian Nezhad ◽  
Marzieh Farhadkhani ◽  
Mahnaz Heidari
Keyword(s):  
Anaerobic Biodegradation ◽  
Methanogenic Activity ◽  
Activity Test ◽  
Specific Methanogenic Activity

Effect of influent pH on hydrolytic acidification performance and bacterial community structure in EGSB for pretreating crotonaldehyde manufacture wastewater after ozonation

2019 ◽  
Vol 79 (6) ◽  
pp. 1174-1183
Author(s):  
Tao Liu ◽  
Zhiqiang Shen ◽  
Chunyu Zhang ◽  
Yudong Song ◽  
Jie Li ◽  
...  
Keyword(s):  
Community Structure ◽  
Volatile Fatty Acids ◽  
Removal Rate ◽  
Oxygen Demand ◽  
Granular Sludge ◽  
Biodegradation Rate ◽  
Biochemical Methane Potential ◽  
Methane Potential ◽  
Cod Removal Rate ◽  
Hydrolytic Acidification

Abstract The objective of this work was to evaluate the effect of influent pH on the hydrolytic acidification (HA) performance and microbial community structure in an expanded granular sludge bed (EGSB) pretreating crotonaldehyde manufacture wastewater (CMW) after ozonation. The results showed that higher chemical oxygen demand (COD) removal rate (40.1%) and acidification degree (27.6%) were obtained at pH 8.0 than those at pH 6.0 and pH 4.0. The concentration of extractable extracellular polymeric substance (EPS) in the sludge gradually decreased with the pH decreasing from 8.0 to 4.0. A similar change was also observed for the concentration of total volatile fatty acids (TVFA) in the effluent. The optimal detoxification efficiency by the HA process was obtained at pH 8.0, with higher removal efficiency (all higher than 90%) of the main toxic pollutants (crotonaldehyde, 5-formyl-6-methyl-4,5-dihydropyran, etc.) and higher anaerobic biodegradation rate (44.5%) in biochemical methane potential (BMP) assay. Among the predominant genera, the Acinetobacter and Pseudomonas were possibly related to biodegradation of pollutants, since their higher relative abundance also coincided with the better performance of the HA process at pH 8.0.

Study on the Startup of Internal Circulation Anaerobic Reactor in Treating Juice Wastewater

2011 ◽  
Vol 281 ◽  
pp. 132-136
Author(s):  
Zhi Jiang Li ◽  
Jin Juan Chi ◽  
Hui Hu ◽  
Ai Yuan Miao
Keyword(s):  
Particle Size ◽  
Volatile Fatty Acids ◽  
Removal Rate ◽  
Granular Sludge ◽  
Internal Circulation ◽  
Anaerobic Reactor ◽  
Volume Load ◽  
Start Up ◽  
Cod Removal Rate ◽  
Sludge Particle

We studied the Internal Circulation (IC) anaerobic reactor start-up progress in treating juice wastewater. The results shown that IC reactor has certain acidoresistant, the pH of inflow water can drop to 6.0, the IC reactor under the circumstance of increasing COD concentration gradually to enhance the volume load, sludge bed zone of the reactor IC was filled fully by granular sludge with good settling property little by little as reactor run .In the bottom of the reactor, granular sludge particle size in 2-3mm were more. And particle size of all the granular sludge under the sludge bed zone was bigger than that the upper. When the COD concentration was about 7000mg/L, HRT remained unchanged for 12 hours. Under the Circumstance of the volume load in 14.15kgCOD/m3.d,COD removal rate kept above 90%. Effluent volatile fatty acids (VFA )stabled at less than 400mg/L.

A ‘Jurist-linguistic’ Reading of the wuḍūʾ Verse (Q. 5:6)

2010 ◽  
Vol 12 (1-2) ◽  
pp. 313-282
Author(s):  
ʿAbd al-ʿAzīz Mūsā
Keyword(s):  
The Third

This article sheds light on the role of grammar in understanding legislative texts, with reference to the wuḍūʾ verse (Q. 5:6). The first section deals with the issue of washing the elbows along with the feet as part of ritual ablution, and lists the various interpretations of the preposition ilā in the aya, and discusses the grammatical theory used by different fuqahāʾ to support their arguments. The second section tackles how much of the head should be rubbed in ritual ablution, with regard to the use of the preposition bi- in the phrase bi-ruʾūsikum, while the third focuses on the two readings of the phrase arjulakum/arjulikum (‘your feet’) and on passing legislative judgement on whether the feet be washed or just rubbed. The study concludes that lugha and fiqh theory are of mutual importance and together help to clarify legislative judgements, and, on this basis, that jurists should not pass any legislative judgement without referring to language.

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