Population dynamics using temporal series analysis in a industrial two-stage activated sludge pilot plant

1998 ◽  
Vol 37 (4-5) ◽  
pp. 255-258
Author(s):  
Eloy Bécares ◽  
Susana Romo ◽  
Margarita Fernandez-Aláez
Keyword(s):  
Activated Sludge ◽  
Pilot Plant ◽  
General Pattern ◽  
Industrial Effluents ◽  
Oscillation Period ◽  
Two Stage ◽  
Simple Method ◽  
Density Dependent ◽  
Series Analysis ◽  
Order Of Magnitude

A time series analysis using an autocorrelation function (ACF) was used to assess the relative importance of density (DD) and non density-dependent - (NDD) factors on microfauna abundance of a two-stage activated sludge pilot plant treating industrial effluents. Although some previous work has detected a carrying capacity for the total microfauna abundance in both reactors, ACF showed a general pattern of non-density dependent abundance regulation. Stationarity due to density-dependent factors was observed for the two major species in the first reactor, the sessile Opercularia asymmetrica and the crawling Chilodonatella minuta. There was no evidence of bacterial competition and only weak evidence of floc surface competition. It is possible that the main driving factor in the first reactor was the constant wasting rate. In the second reactor, the microfauna was clearly dependent on substrate fluctuations, attaining densities one order of magnitude higher than in the first reactor. This was probably a consequence of its longer sludge age. An 8-day oscillation period was detected only in the first reactor, while a second oscillation of about 30 days was observed in both the first and second reactors. ACF was shown to be a simple method for discriminating between DD and NDD factors influencing species and total abundance dynamics.

Nitrification preservation in activated sludge during curative bulking chlorination

2003 ◽  
Vol 47 (11) ◽  
pp. 85-92 ◽  
Author(s):  
E. Cotteux ◽  
P. Duchene
Keyword(s):  
Activated Sludge ◽  
Pilot Plant ◽  
Wastewater Treatment Plants ◽  
Oxygen Uptake Rate ◽  
Ammonia Concentration ◽  
Synthetic Wastewater ◽  
Biological Wastewater Treatment ◽  
Simple Method ◽  
Method Of Measurement ◽  
The Impact

The bulking that occurs in biological wastewater treatment plants using activated sludge is very often controlled by the injection of sodium hypochlorite into the return activated sludge (RAS) stream. In the present study undertaken at two pilot plants fed with synthetic wastewater, the impact of the pass frequency of the sludge at the chlorine dosing point on the nitrifying flora is analysed. The pass frequency is one for the pilot plant 1 and two for the pilot plant 2. A dose of chlorine of 4.85 ± 0.05 g/kg/MLVSS per day was applied at both pilots. The preservative effect on nitrifying activity of the lowest concentration of chlorine at the dosing point and therefore of the highest pass frequency was evidenced. Among other tools, a simple method of measurement of the oxygen uptake rate enabled us to monitor the effect of chlorination on nitrification before recording an increase in the ammonia concentration in the bulking.

Experience with Two-Stage Activated Sludge Plants for Industrial Wastewaters in Korea

1992 ◽  
Vol 25 (4-5) ◽  
pp. 427-428 ◽  
Author(s):  
R. Schulze-Rettmer ◽  
S. S. Kim ◽  
S. S. Son
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Wastewater Treatment Plant ◽  
Pilot Plant ◽  
Treatment Plant ◽  
Activated Sludge Process ◽  
Two Stage ◽  
Industrial Wastewaters ◽  
Textile Dyeing ◽  
One Year

The two-stage activated sludge process (AB-process, i.e. adsorption activated sludge process) invented by Boehnke was successfully applied to several municipal and industrial wastewaters in Korea. The first large wastewater treatment plant for the combined effluents of 22 textile dyeing companies was constructed in Taegu and started operation in 1989. Two years earlier pilot plant runs were performed. The AB-process proved to be superior to any other activated sludge process. BOD was reduced from 1200 mg/l down to 24 mg/l. In the meantime in Korea several further AB-process treatment plants were constructed, the overall planning and constructing period being not longer than one year.

Two stage activated sludge plants – influence of different operational modes on sludge bulking and nitrification

2002 ◽  
Vol 46 (1-2) ◽  
pp. 479-486 ◽  
Author(s):  
G. Wandl ◽  
H. Müller-Rechberger ◽  
N. Matsché ◽  
K. Svardal ◽  
S. Winkler
Keyword(s):  
Activated Sludge ◽  
Nutrient Removal ◽  
Pilot Plant ◽  
Negative Influence ◽  
Hybrid Mode ◽  
Two Stage ◽  
Second Stage ◽  
Pilot Plant Scale ◽  
Two Stages ◽  
Operational Modes

Conventional two stage activated sludge plants often lack sufficient nutrient removal performance due to substrate limitation for denitrification in the second stage. For the extension of the Vienna Main WWTP a two stage concept has been developed and tested by means of a pilot plant (scale 1:10.000). The new concept enables the operation of two different modes: In BYPASS-mode a portion of the primary clarifier effluent is fed directly to the second stage; the HYBRID-mode includes the exchange of mixed liquor between the two stages; over the course of the pilot plant investigations it turned out that nutrient removal is strongly increased in comparison to conventional two stage mode, but the two modes of operation lead to different results with regard to the sludge quality and the nitrification performance. BYPASS mode yields a higher SVI in both stages and a lower nitrification performance in comparison to HYBRID mode. This is caused by the negative influence of the primary effluent on the biocoenosis of the second stage. Additionally, the reduced sludge loading of the first stage in this mode results in a higher sludge age which favours the growth of filaments (Microthrix and Nocardia). In HYBRID-mode the higher load of the first stage results in a lower sludge age, fatty components are metabolized and incorporated in the sludge, thus, the growth of filaments is significantly reduced. Additionally, nitrification inhibiting substances are degraded in the first stage, which results in a higher nitrification performance in the second stage.

Comparison of different operational modes of a two-stage activated sludge pilot plant for the extension of the Vienna STP

2001 ◽  
Vol 44 (1) ◽  
pp. 137-144 ◽  
Author(s):  
H. Müller-Rechberger ◽  
G. Wandl ◽  
S. Winkler ◽  
K. Svardal ◽  
N. Matsché
Keyword(s):  
Activated Sludge ◽  
Simulation Model ◽  
Pilot Plant ◽  
Operating Characteristics ◽  
Two Stage ◽  
Plant Layout ◽  
Operational Modes

A pilot plant has been operated over a period of two years in order to investigate the performance and the operating characteristics of the plant concept developed for the extension of the main Vienna STP and to develop a simulation model which will be applied for operation support of the full stage plant. The pilot plant is a two stage activated sludge plant, each stage comprising of four aeration tanks and a clarifier tank. The pilot plant layout allows three different operational modes, each of which has been operated for several periods. The performance of the pilot plant during these periods is described and the different operational modes are compared to each other.

The Effect of Metallic and Ionic Species on the Performance of a Biological Effluent Treatment System

1977 ◽  
Vol 12 (1) ◽  
pp. 191-212
Author(s):  
B. Volesky ◽  
Q. Samak ◽  
P. Waller
Keyword(s):  
Activated Sludge ◽  
Inorganic Ions ◽  
Industrial Effluents ◽  
Original Data ◽  
Ionic Species ◽  
Threshold Concentration ◽  
Effluent Treatment ◽  
Organic Load ◽  
Metallic Ions ◽  
Activated Sludge Systems

Abstract Review of the available results appearing in the recent literature is presented focusing particularly upon the effects of metallic ions such as Cr, Cu, Zn, Cd, Hg, V, Zn, Ni and Co. Some original data involving the effects of Na are presented and discussed. Development of parameters used in evaluating the influence of toxic or inhibitory species on the mixed microbial population of an activated sludge system is of crucial importance and different techniques employed such as BOD-COD-TOC-removal rates, Oxygen Uptake Rate, and others are discussed, showing relative inadequacy of currently applied assays. From the data available, certain trends can be discerned. There is a definite threshold concentration for each metallic ion, depending on the organic load of the feed. In the order of increasing toxicity to activated sludge systems reflected in lower BOD removals the following metals have been listed as inhibiting factors at concentrations starting from 1 ppm applied on a continuous basis: hexavalent chromium, cobalt, zinc, cadmium, trivalent chromium, copper and nickel. Metals in combination have not been reported to exhibit any significantly different effects as compared to those observed with individually introduced metallic ions. Tolerance of some activated sludge systems to shock loadings by various inorganic ions and metals is reviewed. The conclusions are of particular importance for estimating the performance of biox systems handling industrial effluents which are likely to contain toxic components of inorganic or metallic nature.

The Use of Anoxic Selectors for the Control of Low F/M Activated Sludge Bulking

1989 ◽  
Vol 21 (6-7) ◽  
pp. 609-619 ◽  
Author(s):  
Y.-J. Shao ◽  
David Jenkins
Keyword(s):  
Organic Matter ◽  
Activated Sludge ◽  
Pilot Plant ◽  
Detention Time ◽  
Substrate Removal ◽  
Batch System ◽  
Sludge Bulking ◽  
N Removal ◽  
Soluble Substrate ◽  
Activated Sludge Systems

Laboratory and pilot plant experiments on anoxic selector activated sludge systems were conducted on two wastewaters in some cases supplemented with nitrate, acetate or glucose. To prevent bulking sufficient anoxic selector detention time and nitrate levels must be available to reduce selector effluent soluble COD to below 100 mg/l and to reduce readily metabolizable organic matter to virtually zero (< 1 mg/l). Soluble COD/NO3-N removal stoichiometry is in the range 6.0-6.7. Selector systems have elevated soluble substrate removal and denitrification rates compared to CSTR systems. These rates are not affected greatly by temperature (20-25°C) for CSTR sludges but are for selector sludges. Upon exhaustion of nitrate in a selector soluble COD leaks out of the activated sludge in significant amounts. Thiothrix sp. and type 021N denitrify only to NO2 and at much slower rates than Zoogloearamigera does to N2. A sequencing batch system provides an optimistic estimate of the SVI that can be obtained by an anoxic selector system.

Evaluation of the alternative treatment processes to upgrade an Opium alkaloid wastewater treatment plant

2000 ◽  
Vol 41 (1) ◽  
pp. 223-230 ◽  
Author(s):  
M.F. Sevimli ◽  
A.F. Aydin ◽  
Ì. Öztürk ◽  
H.Z. Sarikaya
Keyword(s):  
Activated Sludge ◽  
Alternative Treatment ◽  
Treatment Plant ◽  
Post Treatment ◽  
Anaerobic Sludge ◽  
Processing Plant ◽  
Two Stage ◽  
Sludge Treatment ◽  
Treatment Processes ◽  
Opium Alkaloid

The aim of this study is to characterize the wastewater from an opium alkaloid processing plant and to evaluate alternative treatment techniques to upgrade an existing full-scale biological activated sludge treatment plant having problems of high residual COD and unacceptable dark brown color. In this content firstly, long term operational records of the two stage aerobic activated sludge treatment plant of the opium alkaloid factory located in Afyon province of Turkiye were evaluated. The operating results for the last three years were statistically analyzed and median and 95-percentile values were determined for the parameters including chemical and biological oxygen demand (COD and BOD5) and treatment efficiencies. Specific wastewater generation was found as 6.7 m3 per ton of the opium capsule processed. In the following stage of the study, three additional treatment processes were experimentally tested: anaerobic pretreatment, post treatment of aerobically treated effluents with lime and ozone. Pilot scale upflow anaerobic sludge blanket reactor (UASBR) experiments have demonstrated that about 70 percent of the incoming COD can be removed anaerobically. Chemical treatability studies with lime for the aerobically treated effluent have shown that about 78 percent color and 46 percent COD removals can be obtained with lime dosage of 25 gl−1. Post treatment of the effluents of the existing two stage aerobic treatment with ozone also resulted in significant color and COD reduction.

Estimation of Kinetic Parameters of Heterotrophic Biomass under Aerobic Conditions and Characterization of Wastewater for Activated Sludge Modelling

1992 ◽  
Vol 25 (6) ◽  
pp. 125-139 ◽  
Author(s):  
J. Kappeler ◽  
W. Gujer
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Kinetic Parameters ◽  
Specific Growth ◽  
Wastewater Treatment Plants ◽  
Simple Method ◽  
Batch Tests ◽  
Different Types ◽  
Heterotrophic Biomass

To predict the behaviour of biological wastewater treatment plants, the Activated Sludge Model No. 1 is often used. For the application of this model kinetic parameters and wastewater composition must be known. A simple method to estimate kinetic parameters of heterotrophic biomass and COD wastewater fractions is presented. With three different types of batch-tests these parameters and fractions can be determined by measuring oxygen respiration. Our measurements showed that the maximum specific growth rate µmax of heterotrophic biomass depends on temperature, reactor configuration and SRT. In typical wastewater treatment plants of Switzerland the amount of readily biodegradable substrate was generally small (about 9 % of the COD in primary effluent). The same method can also be used to determine kinetic parameters of nitrifying biomass.

scholarly journals Simple Method of Approximate Calculation of Statically Indeterminate Trusses

2019 ◽  
Vol 16 (06) ◽  
pp. 1840026 ◽  
Author(s):  
Janusz Rębielak
Keyword(s):  
Approximate Calculation ◽  
Computer Software ◽  
Two Stage ◽  
Simple Method ◽  
Two Stages

The paper presents principles of the simple method which makes possible approximate calculations of statically indeterminate truss systems in two stages. The two-stage method applies rules of other methods used for calculations of statically determinate trusses. In each of the two stages, there are considered statically determinate trusses, patterns of which are obtained as results of suitable withdrawing of appropriate members from the pattern of the basic statically indeterminate truss. There are presented results of calculations carried out for two cases of load for selected type of plane truss together with comparison of outcomes obtained by means of using appropriate computer software.

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