The Role of Particulate Organic Matter and Acetic Acid in the Removal of Phosphate in Anaerobic/Aerobic Activated Sludge Processes

2007 ◽  
Vol 7 (1) ◽  
pp. 61-66 ◽  
Author(s):  
Y. Ubukata
Keyword(s):  
Organic Matter ◽  
Acetic Acid ◽  
Activated Sludge ◽  
Particulate Organic Matter ◽  
Activated Sludge Processes

Simultaneous Removal of Phosphorus and Nitrogen by Sequencing Batch Reactor Activated Sludge Process

1985 ◽  
Vol 17 (11-12) ◽  
pp. 315-316
Author(s):  
Mitsumasa Okada ◽  
Ryuichi Sudo
Keyword(s):  
Organic Matter ◽  
Activated Sludge ◽  
Total Nitrogen ◽  
Total Phosphorus ◽  
Batch Reactor ◽  
Simultaneous Removal ◽  
Activated Sludge Process ◽  
Nitrogen Concentrations ◽  
Stage 1 ◽  
Activated Sludge Processes

Abstract–Phosphorus removal by biological means in continuous-flow aerobic/ anaerobic activated sludge processes is now in a stage of full-scale operations. The similar aerobic/anaerobic treatment is also found in biological processes for nitrogen removal by nitrification followed by denitrification. These processes are successfully applied not only to continuous-flow system but also to sequencing batch reactor (SBR) activated sludge processes, whereas little attempts have been reported on phosphorus removal in SBR activated sludge processes. It is most probable that both phosphorus and nitrogen in addition to organic matter can be removed by the SBR activated sludge processes if aerobic and anaerobic treatments were properly incorporated into a cycle of batch operation. Laboratory scale experiments on aerobic/anaerobic operations of the SBR processes were conducted aiming at simultaneous removal of phosphorus, nitrogen, and organic matter without any addition of chemicals. SBR of 5 1 in working volume was fed with synthetic wastewater in which TOC = 120-200 mg/l, BOD = 200-400 mg/l, total phosphorus = 6-12 mg/1 and total nitrogen = 36-60 mg/1. The following sequence of operations were conducted in a batch cycle; 1) mixing and inflow of wastewater, 2) aeration and mixing, 3) mixing, 4) aeration and mixing, 5) settling and 6) decanting. It was secured from continuous monitoring of dissolved oxygen concentration in the mixed liquor that both anaerobic (stages 1 and 3) and aerobic (stages 2 and 4) treatments were repeated twice in a cycle. In some operations, stages 3 and 4 were omitted for comparison, i.e. anaerobic and aerobic treatments were conducted only once per cycle. The volume of mixed liquor before the inflow of wastewater at the beginning of a cycle (low level) ranged from 33 % to 50 % of that during full volume stages from 2 to 5 (high level). In stage 6, the supernatant was discharged down to the low level and followed by the next cycle of operation. The length of time for a cycle of operation was β h or 9.5 h. Among various types of operations tried, the following sequence was the best in the quality of effluent; 1) 2 h for mixing and inflow, 2) 3 h for aeration and mixing, 3) 3 h for mixing, 4) 20 min for aeration and mixing, 5) 1 h for settling, and 6) 10 min for decanting in a cycle of 9.5 h if influent BOD, total phosphorus and total nitrogen concentrations were 400 mg/1, 12 mg/1 and 60 mg/1, respectively, and BOD loading was 0.68 kg/cu m/d. Total phosphorus and nitrogen concentrations in the effluent were 1.2 mg/1 and 8.0 mg/1, respectively. Similar results were obtained in operations where anaerobic and aerobic treatments were repeated twice in a cycle. In operations where effluent quality was satisfactory, release of phosphorus from the sludge was observed in stage 1. The reactor concentration of filterable total phosphorus (FTP) increased rapidly and its maximum value observed at the end of the stage was ca. 50 mg/1. Phosphorus uptake under aerobic condition (stage 2) decreased FTP to the level of effluent FTP. The luxury uptake of phosphorus by the sludge was noted, i.e. phosphorus content in the sludge ranged from 2.0 % to 4.0 %(w/w). The release of phosphorus from the sludge and subsequent luxury uptake were not significant during stages 3 to 4, hence, further removal of phosphorus was not remarkable. Nitrate nitrogen concentration increased during stage 2 by nitrification. Denitrification was noted both in stages 1 and 3. In stage 1, filterable total organic carbon (FTOC) increased by the inflow of wastewater. It should be, therefore, utilized for denitrification as hydrogen donor. FTOC decreased rapidly after the initiation of aeration in stage 2 and little FTOC remained after the latter half of stage 2. Intracellular organic substances of the sludge, therefore, were regarded to be utilized for denitrification without any addition of chemicals at stage 3. In the best operation, from 50% to 70% out of total nitrogen inflow was removed by denitrification. Effluent BOD was less than 10 mg/l. Although further investigations would be required to determine optimum scheduling in a cycle such as the combination of anaerobic and aerobic periods, the ratio between low and high levels in the reactor, the length of a cycle, and etc. for a given wastewater, the SBR activated sludge process would be a promising wastewater treatment process for simultaneous removal of phosphorus, nitrogen and organiC matter by a single reactor. In spite of complicated operational sequence, full scale automatic operations of SBR activated sludge process would be possible economically even in small-scale plants by using recently advanced microcomputer technology.

Theoretical and Experimental Analysis of the Role of Sludge Age on the Removal of Adsorbed Micropollutants in Activated Sludge Processes

2008 ◽  
Vol 47 (17) ◽  
pp. 6775-6782 ◽  
Author(s):  
Davide Dionisi ◽  
Lorena Bornoroni ◽  
Sara Mainelli ◽  
Mauro Majone ◽  
Francesca Pagnanelli ◽  
...  
Keyword(s):  
Activated Sludge ◽  
Experimental Analysis ◽  
Activated Sludge Processes

Role of biomass adaptation in the removal of formic acid in sequencing batch reactors

2008 ◽  
Vol 58 (2) ◽  
pp. 303-307 ◽  
Author(s):  
D. Dionisi ◽  
M. Majone ◽  
A. Bellani ◽  
C. Cruz Viggi ◽  
M. Beccari
Keyword(s):  
Acetic Acid ◽  
Formic Acid ◽  
Microbial Growth ◽  
Batch Reactors ◽  
Sequencing Batch Reactors ◽  
Batch Tests ◽  
Treatment Processes ◽  
Classical Models ◽  
Activated Sludge Processes

This study deals with formic acid removal in activated sludge processes, in particular in the processes carried out in sequencing batch reactors (SBRs). Formic acid removal has been investigated in a SBR fed with acetic and formic acids at equimolar concentrations. Biomass performance in the reactor has been investigated both by the analysis of the removal of the two substrates and by batch tests. Regarding SBR process, the obtained results show that a relevant difference occurred between formic and acetic acid profiles. Acetic acid was never found in the effluent and was always completely removed during the reaction phase. On the other hand, formic acid removal was determined by biomass acclimation, which is in turn determined by sludge age imposed to the system. Batch tests confirmed that formic acid removal occurs only if biomass is acclimated. It has been shown that the minimal sludge age to obtain complete formic acid removal is much higher than those predictable with the classical models of microbial growth in wastewater treatment processes. The advantages of SBRs over continuous-flow systems in the removal of formic acid have also been highlighted.

scholarly journals The role of log jams and exceptional flood events in mobilizing coarse particulate organic matter in a steep headwater stream

2015 ◽  
Vol 3 (1) ◽  
pp. 173-196 ◽  
Author(s):  
M. Jochner ◽  
J. M. Turowski ◽  
A. Badoux ◽  
M. Stoffel ◽  
C. Rickli
Keyword(s):  
Organic Matter ◽  
Particulate Organic Matter ◽  
Strong Relationship ◽  
Headwater Stream ◽  
Return Periods ◽  
Flood Events ◽  
Coarse Particulate Organic Matter ◽  
Effective Barrier ◽  
Over Time

Abstract. Export rates of coarse particulate organic matter (CPOM) from mountain catchments have been observed to strongly increase with rising discharge, but the mechanism leading to this strong relationship is unclear. Here, we show that log jams in the Erlenbach, a steep headwater stream in the Swiss Prealps, are an effective barrier for the transport of CPOM pieces, and thus become sites of storage of large quantities of material over time. Exceptional discharge events with return periods exceeding 20 years play a dual role in CPOM transport. First, they destroy existing log jams, releasing the stored material (wood and sediment). Second, they intensify channel-hillslope coupling, thereby recruiting new logs to the channel, around which new jams can form.

scholarly journals The role of log jams and exceptional flood events in mobilizing coarse particulate organic matter in a steep headwater stream

2015 ◽  
Vol 3 (3) ◽  
pp. 311-320 ◽  
Author(s):  
M. Jochner ◽  
J. M. Turowski ◽  
A. Badoux ◽  
M. Stoffel ◽  
C. Rickli
Keyword(s):  
Organic Matter ◽  
Particulate Organic Matter ◽  
Strong Relationship ◽  
Headwater Stream ◽  
Mountain Streams ◽  
Flood Events ◽  
Coarse Particulate Organic Matter ◽  
Sediment Transport Capacity ◽  
End Member Model

Abstract. Coarse particulate organic matter (CPOM) fulfills important functions in the physical and ecological system of a stream. CPOM delivery to and export from the stream has implications for the stream's morphology and sediment transport capacity as well as the energy budget and food availability. Export rates of CPOM from mountain catchments have been observed to strongly increase with rising discharge, but the mechanism leading to this strong relationship is unclear. Here, we show that log jams in the Erlenbach, a steep headwater stream in the Swiss Prealps, are an effective barrier for the transport of CPOM pieces, and thus become sites of storage of large quantities of material over time. Exceptional discharge events with return periods exceeding 20 years play a dual role in CPOM transport in the Erlenbach. First, they appear to destroy existing log jams, releasing the stored material (wood and sediment). Second, they intensify channel–hillslope coupling, thereby recruiting new logs to the channel, around which new jams can form. This allows for the formulation of a new, fully episodic end-member in a four-end-member model of CPOM dynamics of steep mountain streams based on wood delivery and export.

Proof of concept for a new energy-positive wastewater treatment scheme

2014 ◽  
Vol 70 (10) ◽  
pp. 1709-1716 ◽  
Author(s):  
C. Remy ◽  
M. Boulestreau ◽  
B. Lesjean
Keyword(s):  
Organic Matter ◽  
Energy Balance ◽  
Activated Sludge ◽  
Municipal Wastewater ◽  
Treatment Plant ◽  
Anaerobic Sludge ◽  
Stable Operation ◽  
Conventional Activated Sludge ◽  
Pilot Trials ◽  
Activated Sludge Processes

For improved exploitation of the energy content present in the organic matter of raw sewage, an innovative concept for treatment of municipal wastewater is tested in pilot trials and assessed in energy balance and operational costs. The concept is based on a maximum extraction of organic matter into the sludge via coagulation, flocculation and microsieving (100 μm mesh size) to increase the energy recovery in anaerobic sludge digestion and decrease aeration demand for carbon mineralisation. Pilot trials with real wastewater yield an extraction of 70–80% of total chemical oxygen demand into the sludge while dosing 15–20 mg/L Al and 5–7 mg/L polymer with stable operation of the microsieve and effluent limits below 2–3 mg/L total phosphorus. Anaerobic digestion of the microsieve sludge results in high biogas yields of 600 NL/kg organic dry matter input (oDMin) compared to 430 NL/kg oDMin for mixed sludge from a conventional activated sludge process. The overall energy balance for a 100,000 population equivalent (PE) treatment plant (including biofilter for post-treatment with full nitrification and denitrification with external carbon source) shows that the new concept is an energy-positive treatment process with comparable effluent quality than conventional processes, even when including energy demand for chemicals production. Estimated operating costs for electricity and chemicals are in the same range for conventional activated sludge processes and the new concept.

Characterization of Wastewater for Modelling of Activated Sludge Processes

1992 ◽  
Vol 25 (6) ◽  
pp. 1-15 ◽  
Author(s):  
Mogens Henze
Keyword(s):  
Organic Matter ◽  
Mathematical Modelling ◽  
Activated Sludge ◽  
Transport System ◽  
Organic Nitrogen ◽  
Suspended Material ◽  
Nitrogen Fractions ◽  
Activated Sludge Processes ◽  
Raw Wastewater

The fractionation of organic matter in the various parts which are used for mathematical modelling is discussed. The fractions include inert soluble, readily biodegradable, rapidly hydrolysable, slowly hydrolysable, biomass and inert suspended material. Methods for measuring are also discussed. Fractionation of biomass in wastewater and in activated sludge is difficult at present, as methods are only partly developed. Nitrogen fractions in wastewater are mainly inorganic. The organic nitrogen fractions are coupled to the organic COD fractions. The fractions of COD, biomass and nitrogen found in a specific wastewater seem to be constant even when concentrations vary. Wastewater input to sewers and the sewer transport system significantly influences the raw wastewater composition at treatment plants.

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