The activated sludge metabolic characteristics changing sole carbon source from readily biodegradable acetate to toxic phenol

2016 ◽  
Vol 73 (10) ◽  
pp. 2324-2331 ◽  
Author(s):  
Changyong Wu ◽  
Yuexi Zhou ◽  
Jiamei Song

A sequencing batch reactor was used to investigate the effect of carbon sources on the metabolism of activated sludge. Acetate and phenol, with the chemical oxygen demand (COD) of 330–350 mg L−1, was used as the carbon source in Periods I and II, respectively. Acetate decreased in the initial 120 min with the intracellular storage materials (XSTO), extracellular polymeric substances (EPS), and the soluble microbial products (SMP) accumulating to 131.0 mg L−1, 347.5 mg L−1, and 35.5 mg L−1, respectively. Then, XSTO and EPS decreased to 124.5 mg L−1 and 340.0 mg L−1, respectively, in the following 120 min. When acetate was replaced by phenol, it could not be used at the beginning due to its toxicity. The XSTO decreased from 142 mg L−1 to 54.6 mg L−1 during the aeration period. The EPS had a significant increase, with the highest value of 618.1 mg L−1, which then decreased to 245.6 mg L−1 at 240 min. The phenol was gradually degraded with the acclimation and it can be fully degraded 18 d later. Meanwhile, the usage ratio of the internal carbon source decreased. The effluent SMP in Period II was 1.7 times that in Period I.

2015 ◽  
Vol 73 (4) ◽  
pp. 740-745 ◽  
Author(s):  
Jan Dries

On-line control of the biological treatment process is an innovative tool to cope with variable concentrations of chemical oxygen demand and nutrients in industrial wastewater. In the present study we implemented a simple dynamic control strategy for nutrient-removal in a sequencing batch reactor (SBR) treating variable tank truck cleaning wastewater. The control system was based on derived signals from two low-cost and robust sensors that are very common in activated sludge plants, i.e. oxidation reduction potential (ORP) and dissolved oxygen. The amount of wastewater fed during anoxic filling phases, and the number of filling phases in the SBR cycle, were determined by the appearance of the ‘nitrate knee’ in the profile of the ORP. The phase length of the subsequent aerobic phases was controlled by the oxygen uptake rate measured online in the reactor. As a result, the sludge loading rate (F/M ratio), the volume exchange rate and the SBR cycle length adapted dynamically to the activity of the activated sludge and the actual characteristics of the wastewater, without affecting the final effluent quality.


2015 ◽  
Vol 72 (9) ◽  
pp. 1653-1661 ◽  
Author(s):  
YangWei Yan ◽  
YuWen Wang ◽  
Yan Liu ◽  
Xiang Liu ◽  
ChenChao Yao ◽  
...  

The effects of synthetic wastewater that contained 20 mg/L Cu(II) on the removal of organic pollutants in a sequencing batch reactor were investigated. Results of continuous 20 mg/L Cu(II) exposure for 120 days demonstrated that the chemical oxygen demand (COD) removal efficiency decreased to 42% initially, followed by a subsequent gradual recovery, which peaked at 78% by day 97. Effluent volatile fatty acid (VFA) concentration contributed 67 to 89% of the influent COD in the experimental reactor, which indicated that the degradation of the organic substances ceased at the VFA production step. Meanwhile, the varieties of soluble microbial products (SMP) content and main components (protein, polysaccharide, and DNA) were discussed to reveal the response of activated sludge to the toxicity of 20 mg/L Cu(II). The determination of Cu(II) concentrations in extracellular polymeric substances (EPS) and SMP throughout the experiment indicated an inverse relationship between extracellular Cu(II) concentration and COD removal efficiency.


Author(s):  
Hongwei Sun ◽  
Chenjian Cai ◽  
Jixue Chen ◽  
Chunyu Liu ◽  
Guangjie Wang ◽  
...  

Abstract In order to investigate the effect of temperatures and operating modes on extracellular polymeric substances (EPS) contents, three sequencing batch reactors (SBRs) were operated at temperatures of 15, 25, and 35 °C (R15 °C, R25 °C, and R35 °C, respectively), with two SBRs operated under alternating anoxic/oxic conditions (RA/O and RO/A, respectively). Results showed that higher contents of tightly bound EPS (TB-EPS) and total EPS appeared in R15 °C, while loosely bound EPS (LB-EPS) dominated in R35 °C. In all three kinds of EPS (LB-EPS, TB-EPS and total EPS) assessed, protein was the main component in R15 °C and R25 °C, while polysaccharides dominated in R35 °C. Moreover, compared with RO/A, RA/O was favorable for the production of the three kinds of EPS. Furthermore, three kinds of EPS and their components were augmented during the nitrification process, while they declined during the denitrification process under all conditions except for R35 °C.


2000 ◽  
Vol 42 (12) ◽  
pp. 65-72 ◽  
Author(s):  
H.-S. Shin ◽  
S.-Y. Nam

A separate sludge system incorporating sequencing batch reactor (SBR) for sequestered denitrification and an immobilized fixed-film reactor for nitrification was investigated in this study. Emphases were placed on the preservation of organic matter as an electron donor for denitrification and the improvement of nitrification efficiency by using an immobilization technique with alginate coating. To preserve organic materials in the sludge required for denitrification, a study was made with a contact process. The contactor, when operated with a short detention time, gave incomplete metabolism of organic matter. With 64% of the influent soluble chemical oxygen demand (SCOD) was adsorbed to activated sludge within 30 min. The specific mass of organic matter uptaken was 55 mg SCOD/g mixed liquor suspended solids (MLSS), which enhanced the denitrification efficiency up to 63% in the following denitrification step. Thus, the required COD in the proposed system can be saved up to 63% as an available electron donor for the conventional aerobic process. The immobilized nitrification unit showed over 90% of nitrate production rate up to 50 mg/l of influent ammonia load.


RSC Advances ◽  
2015 ◽  
Vol 5 (39) ◽  
pp. 30737-30747 ◽  
Author(s):  
Sen Wang ◽  
Mengchun Gao ◽  
Zhichao Wang ◽  
Zonglian She ◽  
Chunji Jin ◽  
...  

The effects of divalent copper (Cu(ii)) on the performance, extracellular polymeric substances (EPS) and microbial community of activated sludge were investigated in an anoxic–aerobic sequencing batch reactor (SBR).


Author(s):  
Ogbebor Daniel ◽  
Ndekwu, Benneth Onyedikachukwu

Aim: The study aimed at designing a wastewater treatment method for removal of (Biological Oxygen Demand) BOD5 using Sequencing batch reactor (SBR). Study Design: SBR functions as a fill-and-draw type of activated sludge system involving a single complete-mix reactor where all steps of an activated sludge process take place. Methodology: The intermittent nature of slaughterhouse wastewaters favours batch treatment methods like sequence batch reactor (SBR). Attempts to remediate the impact of this BOD5 on the stream, led to the design of a sequence batch reactor which was designed to treat slaughterhouse effluent of 1000 L. Results: The oxygen requirement for effective removal of BOD5 to 95% was determined to be 21.10513 kgO2/d, while L:B  of 3:1 was considered for the reactor. Also, air mixing pressure for the design was 0.16835 bar, while settling velocity was . Conclusion: To ensure proper treatment of BOD5 load of the slaughterhouse, a sequencing Batch reactor of 1000 litre carrying capacity was designed. For effective operation of this design, the pressure exerted by the mixing air was 0.16835 bar which was far greater than the pressure exerted by the reactor content and the nozzle. Settling velocity of 0.0003445 m/s for 0.887 hrs was required for the reactor to be stable and a theoretical air requirement of 1.6884 m³/d was calculated. Hence the power dissipated by the rising air bubbles to ensure efficient mixing of oxygen in the reactor was calculated as 26530003.91 Kilowatts. With these design parameters, the high BOD5 load downstream of the river can be treated to fall below the FMEnv recommended limit of 50 mg/l.


Water ◽  
2019 ◽  
Vol 11 (8) ◽  
pp. 1539 ◽  
Author(s):  
Justyna Michalska ◽  
Izabela Greń ◽  
Joanna Żur ◽  
Daniel Wasilkowski ◽  
Agnieszka Mrozik

Hauling landfill leachate to offsite urban wastewater treatment plants is a way to achieve pollutant removal. However, the implementation of biological methods for the treatment of landfill leachate can be extremely challenging. This study aims to investigate the effect of blending wastewater with 3.5% and 5.5% of the industrial leachate from the Kalina pond (KPL) on the performance of sequencing batch reactor (SBR) and capacity of activated sludge microorganisms. The results showed that the removal efficiency of the chemical oxygen demand declined in the contaminated SBR from 100% to 69% and, subsequently, to 41% after the cotreatment with 3.5% and 5.5% of the pollutant. In parallel, the activities of the dehydrogenases and nonspecific esterases declined by 58% and 39%, and 79% and 81% after 32 days of the exposure of the SBR to 3.5% and 5.5% of the leachate, respectively. Furthermore, the presence of the KPL in the sewage affected the sludge microorganisms through a reduction in their functional capacity as well as a decrease in the percentages of the marker fatty acids for different microbial groups. A multifactorial analysis of the parameters relevant for the wastewater treatment process confirmed unambiguously the negative impact of the leachate on the operation, activity, and structure of the activated sludge.


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