Utilization of a Combined Metabolic Uncoupler to Reduce Sludge Yield in Sequence Batch Reactor System

2013 ◽  
Vol 726-731 ◽  
pp. 2808-2812
Author(s):  
Xiao Chi Feng ◽  
Wan Qian Guo ◽  
Wen Biao Jin ◽  
Shan Shan Yang ◽  
Shuai Hao ◽  
...  
Keyword(s):  
Single Dose ◽  
Zeta Potential ◽  
Activated Sludge ◽  
Removal Rate ◽  
Batch Reactor ◽  
Batch Reactors ◽  
Sludge Reduction ◽  
Promising Technique ◽  
Toc Removal ◽  
Sequence Batch Reactor

This paper is to explore the feasibility of a novel combined uncoupler of 3,3ˊ,4ˊ,5-tetrachlorosalicylanilide (TCS) and 2,4,6-trichlorophenol (TCP) on excess activated sludge reduction compared to single dose of TCS and TCP. Four sequenced batch reactors (SBR) were continuously operated during two-month period dosed by different concentration of metabolic uncoupler. The comparative experiments showed that the combined uncoupler could effectively limit sludge yield by approximately 52%, followed by TCS, TCP, without obvious affecting the TOC removal rate and SVI value. At the end of the operation, the variation of zeta potential clearly indicated that uncoupler dosing affected the flocculability of activated sludge. The study demonstrated applying a combined uncoupler was feasible and promising technique to reduce sludge yield in SBR.

Dynamic mathematical modelling of sequencing batch reactors with aerated and mixed filling period

1997 ◽  
Vol 35 (1) ◽  
pp. 105-112 ◽  
Author(s):  
L. Novák ◽  
M. C. Goronszy ◽  
J. Wanner
Keyword(s):  
Activated Sludge ◽  
Batch Reactor ◽  
Major Elements ◽  
Batch Reactors ◽  
Sequencing Batch Reactors ◽  
Nitrogen And Phosphorus ◽  
Sludge Flocs ◽  
Solids Concentration ◽  
A Minor ◽  
Selection Of

Sequencing batch reactors (SBRs) can be successfully operated for both carbon and nutrient removal, including nitrogen and phosphorus. The major elements of design that accomplish population dynamics control to prevent filamentous sludge bulking, cycle time, oxygen supply, biological nitrification, denitrification, phosphorus removal and solids-liquid separation need to be set in such a way that sufficiently optimal conditions are provided to permit the reactions and processes to take place. SBR processing using cyclic activated sludge technology employs biological selectors in the inlet part of the SBR system and a minor sludge recycle stream to ensure influent wastewater is mixed with activated sludge flocs to create favourable conditions for kinetic and metabolic selection of microorganisms producing floccules. Reaction volume, in addition to the designated bottom water level volume, is variable through time fed-batch reactor mode of operation. A mathematical model that describes volume changes and simultaneously the biodegradation kinetics has been developed. The model describes theoretical behaviour of selected parameters of volume, suspended solids concentration, OUR, ammonia and nitrate nitrogen in the selector compartment and the main aerated basin in ideally mixed and filled reactors of the cyclic system during the phase of mixed-fill (selector) and aerated and non-aerated fill (main aeration reactor basin).

Occurrence of Microthrix parvicella in sequencing batch reactors

2014 ◽  
Vol 69 (10) ◽  
pp. 1984-1995 ◽  
Author(s):  
Lana Mallouhi ◽  
Ute Austermann-Haun
Keyword(s):  
Activated Sludge ◽  
Municipal Wastewater ◽  
Batch Reactor ◽  
Oxygen Demand ◽  
Volume Index ◽  
Batch Reactors ◽  
Sequencing Batch Reactors ◽  
Municipal Wastewater Treatment ◽  
Nitrogen And Phosphorus ◽  
Microthrix Parvicella

Sequencing batch reactors (SBRs) are known for high process stability and usually have a good sludge volume index (SVI). Nevertheless, in many SBRs in Germany for municipal wastewater treatment, scum and foam problems can occur, and SVI can be larger than 200 mL/g. The microscopic investigations of the activated sludge from plants with nitrogen and phosphorus removal have shown that Microthrix parvicella is dominant in the activated sludge in most of them. Studies showed that the optimum growth of M. parvicella is performed at a high sludge age (>20 d) and low sludge load in the range of 0.05–0.2 kg of biochemical oxygen demand per kg of total suspended solids per day (kg BOD5/(TSS·d)). The investigations in 13 SBRs with simultaneous aerobic sludge stabilization (most of them are operated with a system called differential internal cycle strategy sequential batch reactor (DIC-SBR)) show that M. parvicella is able to grow in sludge loads less than 0.05 kg BOD5/(kg TSS·d) as well. To optimize the operation of those SBRs, long cycle times (8–12 h) and dosing of iron salts to eliminate long-chain fatty acids are both recommended. This leads to better SVI and keeps M. parvicella at a low frequency.

Treatment of septage using single and two stage activated sludge batch reactors systems

1995 ◽  
Vol 32 (9-10) ◽  
pp. 95-104 ◽  
Author(s):  
A. D. Andreadakis ◽  
G. Kondili ◽  
D. Mamais ◽  
A. Noussi
Keyword(s):  
Activated Sludge ◽  
Nitrogen Removal ◽  
Removal Rate ◽  
Substantial Reduction ◽  
Subsequent Treatment ◽  
Batch Reactors ◽  
Two Stage ◽  
Second Stage ◽  
Nitrogen Concentrations ◽  
Stage System

The cyclic or sequencing batch activated sludge process was applied for the treatment of septage originating from cesspools serving non-sewered areas. Single and two stage systems were investigated in bench scale units. The single stage aerated system was capable in removing practically all the biodegradable COD and producing a well stabilised excess sludge with excellent settling and thickening characteristics. With respect to nitrogen the average removal rate was to the order of 70%, but the performance was unstable due to periodic strong inhibition of the nitrification process. Subsequent treatment in a second stage aerated unit improved nitrification but did not result in higher nitrogen removal rates due to the increased concentrations of oxidised nitrogen. An anoxic second stage post denitrification unit resulted in an overall nitrogen removal of 88%, through a substantial reduction of nitrates. Further improvement of the system, with nitrogen removal of about 95% and average effluent nitrogen concentrations lower than 10 mg.1−1, can be achieved by adoption of a two stage system consisting of a first aerated stage unit, followed by a second stage unit with alternating aerated and anoxic cycles and addition of external carbon during the anoxic cycle.

Anaerobic treatment of leachate using sequencing batch reactor and hybrid bed filter

1997 ◽  
Vol 36 (6-7) ◽  
pp. 501-508 ◽  
Author(s):  
H. Timur ◽  
I. Özturk
Keyword(s):  
Retention Time ◽  
Organic Contaminants ◽  
Loading Rate ◽  
Batch Reactor ◽  
Anaerobic Treatment ◽  
Organic Loading Rate ◽  
Batch Reactors ◽  
Solid Retention Time ◽  
Toc Removal ◽  
Specific Loading

Landfill leachate taken from a young municipal landfill site (≈3.5 years old) containing high organic contaminants (Total Organic Carbon -TOC of about 5000 mg l−1) was treated in bench-scale Anaerobic Sequencing Batch Reactors (ASBR) and an Anaerobic Hybrid Bed Filter (AHBF) at mesophilic conditions. Twenty months of testing has been conducted at varied influent leachate concentration of 546–5770 mgTOC l−1, Hydraulic Retention Time (HRT) of 10–1.5 days and Solid Retention Time (SRT) of 40–9 days in ASBR's, and influent leachate concentration of 1250–4490 mgTOC l−1 and HRT of 5.1–0.9 days in AHBF. ASBR achieved 73.9% TOC removal at maximum organic loading rate of 2.8 kgTOC m−3 d−1 at 1.5 days of HRT, and 65.3% at 0.561 kgTOC kgVSS−1 d−1 of maximum specific loading rate and 2 days of HRT. The AHBF maintained 81.4% TOC removal at 1.2 kgTOC m−3 d−1 of loading and 2.4 days of HRT. Methane conversion ratio averaged 0.742 m3CH4 kgTOC−1 removed at (STP).

scholarly journals Effect of temperatures and alternating anoxic/oxic sequencing batch reactor (SBR) operating modes on extracellular polymeric substances in activated sludge

2020 ◽  
Author(s):  
Hongwei Sun ◽  
Chenjian Cai ◽  
Jixue Chen ◽  
Chunyu Liu ◽  
Guangjie Wang ◽  
...  
Keyword(s):  
Activated Sludge ◽  
Extracellular Polymeric Substances ◽  
Sequencing Batch Reactor ◽  
Batch Reactor ◽  
Batch Reactors ◽  
Sequencing Batch Reactors ◽  
Operating Modes ◽  
Nitrification Process ◽  
Main Component ◽  
Denitrification Process

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.

Effects of Different Thiobacillus on Bioleaching of Heavy Metals of Sewage Sludge in a Sequencing Batch Reactor

2013 ◽  
Vol 807-809 ◽  
pp. 1445-1450
Author(s):  
Jun Zhang ◽  
Hui Ping Yang ◽  
Dun Qiu Wang ◽  
Zheng Shi Zhang
Keyword(s):  
Heavy Metals ◽  
Ferrous Sulfate ◽  
Sequencing Batch Reactor ◽  
Loss Rate ◽  
Removal Rate ◽  
Batch Reactor ◽  
Acidithiobacillus Thiooxidans ◽  
Batch Reactors ◽  
Sequencing Batch Reactors ◽  
Average Loss

A bioleaching experiment was carried out in two sequencing batch reactors (SBR) of 80 L. Acidithiobacillus thiooxidans (A. t) and Acidithiobacillus ferrooxidans (A. f) were enrichment cultured by adding sulfur powder and ferrous sulfate as substrate respectively. Sequential batch leaching ran for three periods in succession. The average removal rate of As, Cd, Cr, Cu, Ni, Pb, Zn was 90.46%, 90.28%, 90.70% and 79.70%, 81.19%, 84.52% respectively. The average loss rate of total nutrient (total account of organic matter, TN, TP and TK) is 35.36%, 33.36% and 35.54% for three runs in sequence. Comparing with A. f, the acidification time of A. t is shortened by 3.0, 6.6 and 4.9 d, with the increase of 13.5 %, 11.2% and 7.3% for the removal rate of heavy metals.

The Mechanism of Activated Sludge Flocculation under Al3+ Dosin

2014 ◽  
Vol 675-677 ◽  
pp. 106-110
Author(s):  
Wan Lin Zheng ◽  
A Sheng Cao ◽  
Yue Wen ◽  
Hai Rong Chen ◽  
Qi Zhou
Keyword(s):  
Zeta Potential ◽  
Activated Sludge ◽  
Interaction Energy ◽  
Equivalent Dose ◽  
Batch Reactors ◽  
Sequencing Batch Reactors ◽  
Total Interaction Energy ◽  
Total Interaction ◽  
Continuous Dosing ◽  
Opposite Tendency

The mechanism governing activated sludge flocculation under Al3+ dosing was studied in this paper. Activated sludge was cultivated in sequencing batch reactors (SBR) at 22°C. Batch dosages of Al3+ were 0.00, 0.125, 0.5, 1 and 1.5meq/L respectively, and continuous dosage was 0.1meq/L. As batch dosage increased, the total interaction energy, zeta potential and turbidity tended to decline, which suggested that batch dosing promoted sludge flocculation. Under the equivalent dose, the zeta potential of continuous dosing was higher, while the LB-EPS content showed the opposite tendency and turbidity reduction was similar. Both batch and continuous dosing promoted flocculation performance: in terms of interaction energy, batch dosing was more effective; while in terms of EPS, it was on the contrary.

Improvement and prediction of OSA system performance in sludge reduction through integration with thermal and mechanical treatment

2016 ◽  
Vol 74 (9) ◽  
pp. 2087-2096 ◽  
Author(s):  
Sara Nazif ◽  
Naser Mehrdadi ◽  
Sajad Zare ◽  
Sarvenaz Mosavari
Keyword(s):  
Thermal Treatment ◽  
Mechanical Treatment ◽  
Removal Rate ◽  
Batch Reactor ◽  
Cod Removal ◽  
Aeration Tank ◽  
Sludge Reduction ◽  
Mechanical Mixing ◽  
Effluent Quality ◽  
Sludge Production

The oxic–settling–anoxic (OSA) process is one of the sludge production reduction methods in the activated sludge process. In this method, sludge is stored in an anaerobic tank within the sludge return line before entrance into an aeration tank. Due to this method's flexibility in application to operating treatment plants and not being energy-consuming, its application is developing. In this research, the improvement of the OSA process is investigated via thermal and mechanical treatment in a sequencing batch reactor (SBR). A pilot-scale reactor and domestic wastewater are used. Sludge was subjected to high temperature in an anaerobic tank using a heat transformer and it was subjected to mechanical shear through mechanical mixing in the anaerobic tank. Different temperatures and voltages were tested. The OSA process reduced sludge production by 24% while the chemical oxygen demand (COD) removal rate decreased from 90% to 86%. Thermal treatment combined with the OSA process caused a maximum of 46% sludge production reduction. However temperatures above 90 °C are not recommended due to a high level of decrease in COD removal. Mechanical mixing in combination with the OSA process led to 34% sludge production reduction. The effluent quality is not affected by the OSA process itself but is slightly reduced by thermal treatment and mechanical mixing. Therefore, for reaching the maximum sludge reduction in OSA plus thermal and mechanical treatment it would be necessary to evaluate the effect of different sets of parameters on effluent quality beside the sludge reduction. For this purpose multi-layer perceptron artificial neural network models are developed to predict the effluent total suspended solids and COD removal efficiency as well as sludge production rate. The models perform well and would be useful tools in determining the optimal set of system operation parameters.

scholarly journals Design of Sequencing Batch Reactor (SBR) Treatment Plant for Abattoir Wastewater (A Case of Apa Mmini Stream)

2020 ◽  
pp. 15-21
Author(s):  
Ogbebor Daniel ◽  
Ndekwu, Benneth Onyedikachukwu
Keyword(s):  
Activated Sludge ◽  
Sequencing Batch Reactor ◽  
Settling Velocity ◽  
Batch Reactor ◽  
Treatment Plant ◽  
Oxygen Demand ◽  
Treatment Method ◽  
Design Parameters ◽  
Sequence Batch Reactor ◽  
The Impact

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.

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