Management of Papermill Wastes: The Role of Filamentous Microorganisms as Indicators

1994 ◽  
Vol 29 (7) ◽  
pp. 185-188 ◽  
Author(s):  
L. Cingolani ◽  
E. Ciccarelli ◽  
M. Cossignani ◽  
Q. Tornari ◽  
V. Scarlata
Keyword(s):  
Statistical Analysis ◽  
Activated Sludge ◽  
Nutrient Deficiency ◽  
High Load ◽  
Operating Conditions ◽  
Sludge Treatment ◽  
Filamentous Microorganisms ◽  
Made In

A study was made at nine papermill activated sludge treatment plants, affected by bulking phenomena, on the behaviour of filamentous microorganisms in connection with plant performances. In the sludge samples 24 organisms were identified, the most frequently observed being type 0041 and 0675. The principal causes of inconvenience, isolated through statistical analysis, were identified as low oxygenation, high load, low F/M, nutrient deficiency. Changes made in operating conditions improved bulking in some plants.

Behaviour of Alkylphenol Polyethoxylate Surfactants and of Nitrilotriacetate in Sewage Treatment

1987 ◽  
Vol 19 (3-4) ◽  
pp. 449-460 ◽  
Author(s):  
W. Giger ◽  
M. Ahel ◽  
M. Koch ◽  
H. U. Laubscher ◽  
C. Schaffner ◽  
...  
Keyword(s):  
Activated Sludge ◽  
Sewage Treatment ◽  
Operating Conditions ◽  
Municipal Sewage ◽  
Sludge Treatment ◽  
Loading Rates ◽  
Treatment Conditions ◽  
Physico Chemical ◽  
Treated Sewage ◽  
Removal Efficiencies

Effluents and sludges from several municipal sewage treatment plants in Switzerland were analyzed for nonylphenol polyethoxylates (NPnEO, n=3-20), nonylphenol mono- and diethoxylate (NPlEO, NP2EO), corresponding nonylphenoxy carboxylic acids (NP1EC, NP2EC) and nonylphenol (NP). These chemicals derive from nonionic surfactants of the NPnEO-type, and specific analitical techniques were used to study their behaviour during mechanical-biological sewage and subsequent sludge treatment. The parent NPnEO-surfactants, with concentrations in raw and mechanically treated sewage from 400-2200 mg/m3, were relatively efficiently removed by the activated sludge treatment. The abundances of the different metabolites varied depending on treatment conditions. The refractory nature of NPl/2EO, NP and NPl/2EC was recognized. Both biotransformations and physico-chemical processes determine the behaviour and fate of nonylphenolic substances in sewage treatment. Nitrilotriacetate (NTA) was found in primary effluents at concentrations between 430 and 1390 mg/m3. The various treatment plants showed different removal efficiencies for NTA depending on the operating conditions. Activated sludge treatment with low sludge loading rates and nitrifying conditions removed NTA with efficiencies between 95 and 99%. High sludge loading caused a decrease in NTA removal efficiencies from 70% to 39%.

Validation of On-line Respiration Meter and its Applications by Computer Simulation

1992 ◽  
Vol 26 (5-6) ◽  
pp. 1355-1363 ◽  
Author(s):  
C-W. Kim ◽  
H. Spanjers ◽  
A. Klapwijk
Keyword(s):  
Steady State ◽  
Activated Sludge ◽  
Respiration Rate ◽  
Oxygen Demand ◽  
Operating Conditions ◽  
Mass Balances ◽  
Short Term ◽  
Respiration Rates ◽  
On Line ◽  
Made In

An on-line respiration meter is presented to monitor three types of respiration rates of activated sludge and to calculate effluent and influent short term biochemical oxygen demand (BODst) in the continuous activated sludge process. This work is to verify if the calculated BODst is reliable and the assumptions made in the course of developing the proposed procedure were acceptable. A mathematical model and a dynamic simulation program are written for an activated sludge model plant along with the respiration meter based on mass balances of BODst and DO. The simulation results show that the three types of respiration rate reach steady state within 15 minutes under reasonable operating conditions. As long as the respiration rate reaches steady state the proposed procedure calculates the respiration rate that is equal to the simulated. Under constant and dynamic BODst loading, the proposed procedure is capable of calculating the effluent and influent BODst with reasonable accuracy.

Relationships between Population Dynamics and Operating Parameters in an Activated Sludge-Plant by Statistical Analysis

1992 ◽  
Vol 25 (4-5) ◽  
pp. 399-400 ◽  
Author(s):  
L. Cingolani ◽  
M. Cossignani ◽  
R. Miliani
Keyword(s):  
Population Dynamics ◽  
Statistical Analysis ◽  
Activated Sludge ◽  
Treatment Plant ◽  
Operating Conditions ◽  
Statistical Analyses ◽  
Operating Parameters ◽  
Aerobic Treatment

Statistical analyses were applied to data from a series of 38 samples collected in an aerobic treatment plant from November 1989 to December 1990. Relationships between microfauna structure and plant operating conditions were found. Amount and quality of microfauna groups and species found in activated sludge proved useful to suggest the possible causes of disfunctions.

Influences of wastewater composition and operating conditions on activated sludge bulking and scum formation

1994 ◽  
Vol 30 (11) ◽  
pp. 181-189 ◽  
Author(s):  
Jürg Kappeler ◽  
Willi Gujer
Keyword(s):  
Activated Sludge ◽  
Retention Time ◽  
Mass Fraction ◽  
Oxygen Supply ◽  
Reactor Design ◽  
Operating Conditions ◽  
Reactor Configuration ◽  
Growth Requirements ◽  
Filamentous Microorganisms ◽  
Solids Retention

Bulking and scum formation (scumming) are common phenomena in activated sludge plants. Four main problem groups with filamentous microorganisms with different growth requirements are distinguished: (1) “Aerobic Bulking”, (2) “Scumming due to Actinomycetes”, (3) “Low F/M Bulking and Scumming” and (4) “Bulking due to Sulphide Oxidising Bacteria”. Various wastewater fractions, such as readily biodegradable substrate, surfactants, hydrophilic and lipophilic slowly-biodegradable substrate, inoculated filamentous microorganisms and sulphide, strongly influence the biocenosis composition. Apart from wastewater composition, operating conditions, such as solids retention time, reactor configuration, mechanical stress by recirculation pumps and insufficient oxygen supply, are often decisive for the occurrence of a bulking or scumming problem, as well. A predictive scheme for the possible occurrence of the four main problem groups is presented for different combinations of wastewater compositions, operating conditions and reactor design. All four problem groups can occur in aerobic nitrifying systems. In non-nitrifying systems, only “Aerobic Bulking” and “Bulking due to Sulphide Oxidising Bacteria” are expected, depending on wastewater composition and operating conditions. In systems with a large anoxic mass fraction, “Low F/M Bulking and Scumming” is typically the only problem group. Since wastewater fractions can hardly be manipulated in practice, at least operating conditions and reactor design should be optimised in order to obtain a better performance of the plants.

Filamentous Bulking in Nutrient Removal Activated Sludge Systems

1988 ◽  
Vol 20 (4-5) ◽  
pp. 1-8 ◽  
Author(s):  
Jiri Wanner ◽  
Petr Grau
Keyword(s):  
Activated Sludge ◽  
Nutrient Removal ◽  
Point Of View ◽  
Anoxic Conditions ◽  
Filamentous Bulking ◽  
Filamentous Microorganisms ◽  
Substrate Hydrolysis ◽  
Activated Sludge Systems

Behaviour of filamentous microorganisms under anaerobic, anoxic, and oxic conditions has been reviewed from the point of view of filamentous bulking in nutrient removal activated sludge systems. It was concluded that the growth of most filamentous microorganisms is considerably suppressed under anaerobic and anoxic conditions and that the filamentous bulking in nutrient removal systems is chiefly caused by the growth of filamentous microorganisms in oxic zones. The role of particulate substrate hydrolysis was also discussed and the necessity of compartmentalization of oxic zones was shown.

Bench-Scale Testing of Activated Sludge Treatment for a TMP Wastewater

1993 ◽  
Vol 28 (3) ◽  
pp. 571-596 ◽  
Author(s):  
Susan F. Liver ◽  
Henry K. Miyamoto ◽  
Steve A. Black
Keyword(s):  
Activated Sludge ◽  
Full Scale ◽  
Operating Conditions ◽  
Cold Weather ◽  
Sludge Treatment ◽  
Bench Scale ◽  
Conventional Activated Sludge ◽  
Initial Batch ◽  
Treated Effluent ◽  
Biokinetic Parameters

Abstract A continuous bench-scale treatability study determined the most desirable design and operating parameters for waste treament of effluent from an integrated Canadian TMP newsprint operation. An initial batch study indicated that the effluent was biologically treatable and provided initial biological kinetic (biokinetic) parameters for this wastewater. This information was used to design the continuous study. Conventional activated sludge treatment of the mill wastewater can produce an effluent which meets the federal regulations for BOD5, suspended solids, and toxicity to D. magna. Predictions using cumulative toxicity units (CTU) indicate that the treated effluent would also be non-toxic to O. mykiss as well. Analyses of ammonia in the treated effluent indicated that un-ionized ammonia concentrations would be non-toxic to rainbow trout. Mass balances incorporating the results of the bench-scale studies and the effect of fibre carry-over from the primary clarifier, defined the full-scale operating conditions selected as: an F/M of 0.35 d−1, HRT of 0.5 days, SRT of 6 days and an MLSS of 4400 mg/L (when no polymer is used at the primary clarifier). These conditions were arrived at by selecting the smallest HRT which still corresponded to an MLSS < 5000 mg/L, an F/M < 0.4 d−1 and an SRT > 5 days. Based on the kinetics for biological treatment of mill effluent, at the maximum mill production, adequate BOD5 removal will still easily be obtained under the above operating conditions, even during cold weather periods. Operational concerns identified by bench-scale testing indicated that a full-scale facility should incorporate an anoxic selector (although the anoxic selector did not show measurable improvement in the bench-scale tests) and micronutrient addition for filamentous bulking control.

Chlorinated Phenolics Removal from Bleached Kraft Mill Wastewater in Three Secondary Treatment Processes

1994 ◽  
Vol 29 (5-6) ◽  
pp. 177-187 ◽  
Author(s):  
E. R. Hall ◽  
W. G. Randle
Keyword(s):  
Activated Sludge ◽  
Treatment Process ◽  
Operating Conditions ◽  
Secondary Treatment ◽  
Threshold Values ◽  
Sludge Treatment ◽  
Treatment Processes ◽  
Kraft Mill Effluent ◽  
Kraft Mill ◽  
Removal Efficiencies

Laboratory-scale activated sludge (AS), facultative stabilization basin (FSB) and aerated stabilization basin (ASB) processes were operated in parallel treating bleached kraft mill effluent under controlled SRT and temperature conditions, to assess the chlorinated phenolics removal efficiencies attainable in each. The structure and extent of chlorination of the chlorophenolic compounds monitored appeared to contribute to the differing removal efficiencies observed. Under most operating conditions, treatment process effluents contained chronically toxic levels of pentachlorophenol-equivalent toxicity (TEQ). A companson of the results obtained from the FSB, ASB and AS processes indicated that, under most operating conditions, chlorophenolics removal in low rate treatment systems is superior to that in a higher rate activated sludge treatment process. However, it was also observed that operation at long SRT and moderate temperature permitted enhanced removal of chlorophenolics and reduced TEQs to less than threshold values, in all three treatment processes.

scholarly journals The influence of operating conditions of activated-sludge treatment on the behaviour of f2 coliphage

1979 ◽  
Vol 82 (2) ◽  
pp. 285-291 ◽  
Author(s):  
S. A. Balluz ◽  
M. Butler
Keyword(s):  
High Temperature ◽  
Activated Sludge ◽  
Suspended Solids ◽  
Operating Conditions ◽  
Regression Coefficients ◽  
Sludge Treatment ◽  
Mixed Liquor ◽  
Treatment Conditions ◽  
Solids Concentration ◽  
Flow Through

SUMMARYThe behaviour of f2 coliphage during activated-sludge treatment was influenced by the temperature, flow-through-time, concentration of mixed liquor suspended solids and the virus load.The most sensitive way to detect behavioural changes was to examine the regression coefficients for the rate of uptake or loss of virus by the mixed liquor solids. This type of analysis revealed, for instance, high values when the solids concentration was high and even greater values occured when high inocula were used. At high temperature the rate of loss of virus titre after inoculation had stopped was greater than the rate of uptake of virus during inoculation although in all other conditions uptake occurred at a greater rate than the loss of virus. The coefficients were relatively low when the flow rate was increased, when the temperature was low or when the inoculum was small.The distribution of virus between the solids and liquid fractions of the mixed liquor varied somewhat for all conditions but was notably different when (a) the plant was incubated at 5 °C when there was much less virus in the solids fraction than usual, and (b) when the inoculum was low and a much higher proportion of virus was found in the solids.The efficiency with which virus was removed across the plant was the least-sensitive determinant of viral behaviour and the value was about the same for most treatment conditions. However, low or high inocula did result in some increased or decreased removal of virus, respectively.

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