scholarly journals Organic loading rate shock impact on extracellular polymeric substances and physicochemical characteristics of nitrifying sludge treating high-strength ammonia wastewater under unsteady-state conditions

RSC Advances ◽  
2018 ◽  
Vol 8 (73) ◽  
pp. 41681-41691 ◽  
Author(s):  
Lei Yang ◽  
Yong-Xiang Ren ◽  
Ning Chen ◽  
Shen Cui ◽  
Xu-Hui Wang ◽  
...  
Keyword(s):  
Extracellular Polymeric Substances ◽  
Loading Rate ◽  
High Strength ◽  
Physicochemical Characteristics ◽  
Organic Loading Rate ◽  
Unsteady State ◽  
Organic Loading ◽  
Shock Impact ◽  
High Strength Ammonia Wastewater ◽  
The Impact

Laboratory experimentation was used to investigate the impact of the organic loading rate shock on extracellular polymeric substances (EPSs) and the physicochemical characteristics of nitrifying sludge (NS) treating high-strength ammonia wastewater.

Granulation of biological flocs under elevated pressure: characteristics of granules

2013 ◽  
Vol 67 (12) ◽  
pp. 2850-2855
Author(s):  
Yang-Min Liang ◽  
Jie-Yuan Chen ◽  
Gaëtan Marchesini ◽  
Chi-Wang Li ◽  
Shiao-Shing Chen
Keyword(s):  
Extracellular Polymeric Substances ◽  
Loading Rate ◽  
Ambient Pressure ◽  
Elevated Pressure ◽  
Volume Index ◽  
Organic Loading Rate ◽  
Organic Loading ◽  
Oxygen Penetration ◽  
Long Term Stability

Aerobic granules (AG) have good settling ability and are relatively insensitive to the variation of organic loading rate. When sizes of granules become bigger, substrate and oxygen become limited in the granule core, leading to cell lysis and disintegration of granules. The higher the dissolved oxygen, the deeper the oxygen penetration inside AG. AG operated under elevated pressure might be a possible way to maintain long-term stability of granules. In this study, formation and characteristics of AG in the reactor operated under elevated high pressure (HP) and ambient pressure (AP) are investigated. Results show that both systems removed an average 95% of total organic carbon. Sludge volume index at 5 and 30 min settling times under HP are 35% smaller those under AP, indicating that HP granules have a better settling ability and a denser structure than AP granules. The granule size in the HP system is very uniform, while size distribution in the AP system is broader, indicating that the AP system contains flocculent sludge. Extracellular polymeric substances and polysaccharides (PS) are almost the same for HP and AP; however, exopolymeric protein (PN) is very different. PS/PN ratio for HP sludge is four times that of AP. The result is consistent with sludge settleability, which is improved with increasing PS/PN ratio.

scholarly journals Efficient high strength petrochemical wastewater treatment in a hybrid vertical anaerobic biofilm (HyVAB) reactor: a pilot study

2017 ◽  
Vol 12 (3) ◽  
pp. 501-513 ◽  
Author(s):  
Shuai. Wang ◽  
Nirmal. Ghimire ◽  
Gang. Xin ◽  
Eshetu. Janka ◽  
Rune. Bakke
Keyword(s):  
Wastewater Treatment ◽  
Hydraulic Retention Time ◽  
Loading Rate ◽  
High Strength ◽  
Pilot Scale ◽  
Organic Loading Rate ◽  
Anaerobic Sludge ◽  
Organic Loading ◽  
Petrochemical Wastewater ◽  
Step Flow

Performance of a pilot scale Hybrid Vertical Anaerobic Biofilm (HyVAB) reactor treating petrochemical refinery wastewater is presented here. The reactor is an integration of a bottom anaerobic sludge bed and a top aerobic biofilm stage and was operated continuously for 92 days at 21 ± 2 °C. Wastewater was fed continuously to the reactor with step flow increases reducing hydraulic retention time from 55 to 12 hours, increasing organic loading rate from 3 to 33 kg-COD/m3·d. The HyVAB removed on average 91% and 86% of the soluble and total feed COD, respectively, at steady state and loads up to 23 kg-COD/m3·d, of which 98% of the soluble COD removal occurred in the anaerobic stage. Methane yield ranged from 0.29 to 0.51 L/g-COD removed, including conversion of settled aerobic sludge to methane. Sludge production was low (0.04 kg-VSS/kg-COD removed) and biogas methane content high (84 ± 2%). The results demonstrated that HyVAB is an efficient, low footprint alternative for high strength wastewater treatment.

scholarly journals Enhanced Anaerobic Digestion by Stimulating DIET Reaction

Processes ◽  
2020 ◽  
Vol 8 (4) ◽  
pp. 424 ◽  
Author(s):  
Alsayed Mostafa ◽  
Seongwon Im ◽  
Young-Chae Song ◽  
Yongtae Ahn ◽  
Dong-Hoon Kim
Keyword(s):  
Anaerobic Digestion ◽  
Mechanism Of Action ◽  
Loading Rate ◽  
Review Article ◽  
Organic Loading Rate ◽  
Organic Loading ◽  
Interspecies Electron Transfer ◽  
Diet History ◽  
The Impact ◽  
Harsh Conditions

Since the observation of direct interspecies electron transfer (DIET) in anaerobic mixed cultures in 2010s, the topic “DIET-stimulation” has been the main route to enhance the performance of anaerobic digestion (AD) under harsh conditions, such as high organic loading rate (OLR) and the toxicants’ presence. In this review article, we tried to answer three main questions: (i) What are the merits and strategies for DIET stimulation? (ii) What are the consequences of stimulation? (iii) What is the mechanism of action behind the impact of this stimulation? Therefore, we introduced DIET history and recent relevant findings with a focus on the theoretical advantages. Then, we reviewed the most recent articles by categorizing how DIET reaction was stimulated by adding conductive material (CM) and/or applying external voltage (EV). The emphasis was made on the enhanced performance (yield and/or production rate), CM type, applied EV, and mechanism of action for each stimulation strategy. In addition, we explained DIET-caused changes in microbial community structure. Finally, future perspectives and practical limitations/chances were explored in detail. We expect this review article will provide a better understanding for DIET pathway in AD and encourage further research development in a right direction.

Impact of Organic Loading Rate and DO on Filamentous Bulking Sludge and the Study of its Characteristics in Membrane Bioreactor

2010 ◽  
Vol 113-116 ◽  
pp. 1280-1284 ◽  
Author(s):  
Yu Tian ◽  
Xin Ying Su ◽  
Lin Chen ◽  
Tian Ling Jiang
Keyword(s):  
Membrane Fouling ◽  
Membrane Bioreactor ◽  
Loading Rate ◽  
Organic Loading Rate ◽  
Filamentous Bacteria ◽  
Organic Loading ◽  
High Substrate Concentration ◽  
Filamentous Bulking ◽  
And Control ◽  
The Impact

The membrane fouling behaviors and fouling mechanism of filamentous bulking sludge in membrane bioreactor (MBR) have been reported in recent studies. However, few studies have been conducted towards the causes and control of filamentous bulking sludge in MBR. In order to make clear the conditions of filamentous bacteria overgrowth in MBR, the impact of DO and organic loading rate on filamentous growth and its characteristics were investigated in this paper. The results showed that overgrowth of filamentous bacteria occurred under a relatively high substrate concentration (organic loading rate was 0.61 KgCOD/(KgMLSS•d), and DO was above 2 mg/L) in MBR. Nutrient removal effect can not be deteriorated under filamentous bulking sludge, with average 95, 57 and 92% removal efficiencies of COD, TN and TP respectively. The particle size of filamentous sludge was larger than that of normal sludge and the filamentous bacteria produced more SMP and EPS than floc forming bacteria.

Organic loading rate shock impact on operation and microbial communities in different anaerobic fixed-bed reactors

2013 ◽  
Vol 140 ◽  
pp. 211-219 ◽  
Author(s):  
Hongyan Zhao ◽  
Jie Li ◽  
Jiajia Li ◽  
Xufeng Yuan ◽  
Renzhe Piao ◽  
...  
Keyword(s):  
Microbial Communities ◽  
Loading Rate ◽  
Fixed Bed ◽  
Organic Loading Rate ◽  
Organic Loading ◽  
Fixed Bed Reactors ◽  
Shock Impact

Treatment of Sago Wastewater using Hybrid Anaerobic Reactor

2006 ◽  
Vol 41 (1) ◽  
pp. 56-62 ◽  
Author(s):  
J. Rajesh Banu ◽  
Sudalyandi Kaliappan ◽  
Dieter Beck
Keyword(s):  
Loading Rate ◽  
Low Cost ◽  
High Strength ◽  
Organic Loading Rate ◽  
Hybrid Reactor ◽  
Small Scale ◽  
Anaerobic Sludge ◽  
Organic Loading ◽  
Volatile Solids ◽  
Anaerobic Sludge Blanket

Abstract Sago, tapioca starch, is manufactured by over 800 small-scale units located in the Salem district of the State of Tamilnadu, South India. These units generate large quantities of high-strength wastewater requiring elaborate treatment prior to disposal. The present study is an attempt to treat the sago wastewater using a hybrid reactor, which combines the advantages of both fixed-film and up-flow anaerobic sludge blanket systems. A hybrid reactor with a volume of 5.9 L was operated at organic loading rates varying from 10.4 to 24.6 kg COD/m3d. After 120 d of start-up, an appreciable decrease in COD and efficient removal of solids were evident. The COD removal varied from 91 to 83%. While the removal of total solids was in the range of 56 to 63%, that of volatile solids varied from 67 to 72%. The methane production during the study period was in the range of 0.11 to 0.14 L CH4/g COD-d and the percentage was from 55 to 67%. The ideal organic loading rate (OLR) was determined on the basis of tolerance of the reactor towards higher organic loading rate and it was found to be 23.4 kg COD/m3d. The findings of the study open new possibilities for the design of low-cost and compact on-site treatment systems with very short retention periods.

Anaerobic Treatment of Polyethylene Terephthalate (PET) Wastewater from Lab to Full Scale

1999 ◽  
Vol 40 (8) ◽  
pp. 229-236 ◽  
Author(s):  
F. Fdz-Polanco ◽  
M. D. Hidalgo ◽  
M. Fdz-Polanco ◽  
P. A. García Encina
Keyword(s):  
Polyethylene Terephthalate ◽  
Loading Rate ◽  
Treatment Plant ◽  
Textile Wastewater ◽  
Anaerobic Treatment ◽  
Cod Removal ◽  
Organic Loading Rate ◽  
Foam Formation ◽  
Organic Loading ◽  
Start Up

In the last decade Polyethylene Terephthalate (PET) production is growing. The wastewater of the “Catalana de Polimers” factory in Barcelona (Spain) has two main streams of similar flow rate, esterification (COD=30,000 mg/l) and textile (COD=4000 mg/l). In order to assess the anaerobic treatment viability, discontinuous and continuous experiments were carried out. Discontinuous biodegradability tests indicated that anaerobic biodegradability was 90 and 75% for esterification and textile wastewater. The textile stream revealed some tendency to foam formation and inhibitory effects. Nutrients, micronutrients and alkali limitations and dosage were determined. A continuous lab-scale UASB reactor was able to treat a mixture of 50% (v) esterification/textile wastewater with stable behaviour at organic loading rate larger than 12 g COD/l.d (0.3 g COD/g VSS.d) with COD removal efficiency greater than 90%. The start-up period was very short and the recuperation after overloading accidents was quite fast, in spite of the wash-out of solids. From the laboratory information an industrial treatment plant was designed and built, during the start-up period COD removal efficiencies larger than 90% and organic loading rate of 0.6 kg COD/kg VSS.d (5 kg COD/m3.d) have been reached.

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