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.

Optimal sludge retention time for a bench scale MBR treating municipal sewage

2008 ◽  
Vol 57 (3) ◽  
pp. 319-322 ◽  
Author(s):  
A. Pollice ◽  
G. Laera ◽  
D. Saturno ◽  
C. Giordano ◽  
R. Sandulli
Keyword(s):  
Activated Sludge ◽  
Membrane Bioreactor ◽  
Municipal Wastewater ◽  
Operating Conditions ◽  
Municipal Sewage ◽  
Process Conditions ◽  
Physical Parameters ◽  
Municipal Wastewater Treatment ◽  
Bench Scale ◽  
Conventional Activated Sludge

Membrane bioreactors allow for higher sludge concentrations and improved degradation efficiencies with respect to conventional activated sludge. However, in the current practice these systems are often operated under sub-optimal conditions, since so far no precise indications have yet been issued on the optimal operating conditions of MBR for municipal wastewater treatment. This paper reports some results of four years of operation of a bench scale membrane bioreactor where steady state conditions were investigated under different sludge retention times. The whole experimental campaign was oriented towards the investigation of optimal process conditions in terms of COD removal and nitrification, biomass activity and growth, and sludge characteristics. The membrane bioreactor treated real municipal sewage, and four different sludge ages were tested (20, 40, 60, and 80 days) and compared with previous data on complete sludge retention. The results showed that the the biology of the system, as assessed by the oxygen uptake rate, is less affected than the sludge physical parameters. In particular, although the growth yield was observed to dramatically drop for SRT higher than 80 days, the biological activity was maintained under all the tested conditions. These considerations suggest that high SRT are convenient in terms of limited excess sludge production without losses of the treatment capacity. Physical characteristics such as the viscosity and the filterability appear to be negatively affected by prolonged sludge retention times, but their values remain within the ranges normally reported for conventional activated sludge.

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%.

Chemical characterization and biotreatability of effluents from an integrated alkaline-peroxide mechanical pulping/machine finish coated (APMP/MFC) paper mill

1997 ◽  
Vol 35 (2-3) ◽  
pp. 7-14 ◽  
Author(s):  
A. Schnell ◽  
M. J. Sabourin ◽  
S. Skog ◽  
M. Garvie
Keyword(s):  
Activated Sludge ◽  
Aquatic Toxicity ◽  
Wood Chip ◽  
Chemical Characterization ◽  
Toxicity Testing ◽  
Sampling Period ◽  
Paper Mill ◽  
Alkaline Peroxide ◽  
Conventional Activated Sludge ◽  
Treated Effluent

As part of an extensive audit of the Alkaline-Peroxide Mechanical Pulping (APMPTM) plant at the Malette Quebec Inc. mill in St. Raymond, Que., effluents were sampled from various stages of the process for comprehensive chemical characterizations, aquatic toxicity testing and anaerobic biotreatability assessments. In addition, untreated and secondary treated combined effluent from the integrated paper mill were sampled to determine the effectiveness of a conventional activated sludge process at the mill site. During the one-day sampling period, the APMP plant processed a mixed wood furnish consisting of 50% spruce/balsam fir and 50% aspen, with a chemical charge of 3.5% sodium hydroxide and 3.8% hydrogen peroxide on oven-dry fibre, while the Machine Finish Coated (MFC) paper production rate was 100 odt/d (oven dry metric tonnes per day). Measured production-specific contaminant discharge loadings from the novel APMP process were 56 kg BOD5/odt and 155 kg COD/odt in a combined effluent flow of 28 m3/odt. Sources of process effluent were chip washing, three stages of wood chip pretreatment and chemical impregnation (i.e., Impressafiner stages), interstate washing and pulp cleaning. The three Impressafiner pressates were found to be the most concentrated (i.e., 12-26 g COD/L) and toxic streams. Microtox testing of the pressates revealed EC50 concentrations of 0.07-0.34% v/v. The warm and concentrated effluents generated by the non-sulphur APMP process were found to be highly amenable to anaerobic degradation as determined by batch bioassay testing. Filterable BOD5 and COD(f) of the process effluents were reduced by 87-95% and 70-77%, respectively, with corresponding theoretical methane yields being attained. Acid-soluble dissolved lignin compounds exhibited biorecalcitrance, as revealed by limited removals of 34-55%, and were the main constituents contributing to residual COD(f), while resin and fatty acids (RFA) were reduced by 80-94%. The conservatively operated full scale activated sludge treatment process achieved a similar high 74% COD(f) removal from the whole mill effluent, while BOD5 and RFA reductions were virtually complete and the treated effluent was non-toxic, as measured by Microtox.

Carbon Dioxide in Pulp and Paper Mill Effluents from Oxygen-Activated Sludge Treatment Plants as a Potential Source of Distress and Toxicity to Fish

2000 ◽  
Vol 35 (2) ◽  
pp. 189-200 ◽  
Author(s):  
Brian O’Connor ◽  
Tibor Kovacs ◽  
Sharon Gibbons ◽  
Al Strang
Keyword(s):  
Carbon Dioxide ◽  
Rainbow Trout ◽  
Activated Sludge ◽  
Treatment Plant ◽  
Carbon Dioxide Concentration ◽  
Regulatory Compliance ◽  
Sludge Treatment ◽  
Ph Adjustment ◽  
Paper Mill Effluents ◽  
Treated Effluent

Abstract Rainbow trout exposed to effluent from a UNOX (oxygen activated sludge) treatment plant were found to exhibit signs of distress during the first hours of exposure. While the final effluent was not acutely lethal at full strength, it was still important to determine the cause of the distress to ensure that the mill's effluents remain in regulatory compliance. The use of a series of effluent manipulations involving pH adjustment and aeration as well as observations of symptoms exhibited by the fish were successful in identifying carbon dioxide as the cause of fish distress for the UNOX-treated effluent. For rainbow trout, the symptoms of exposure to elevated levels of carbon dioxide of 100 mg/L or greater included loss of equilibrium, erratic swimming, gasping at the surface, sinking to the bottom of the test container and paralysis. The fish were found to eventually recover as the carbon dioxide was stripped from the effluent due to aeration during the test. A carbon dioxide concentration of 250 mg/L, however, was found to be lethal to trout A survey of mills using oxygen activated sludge treatment systems indicated that the carbon dioxide levels in effluents from such operations can range from 48 to 251 mg/L. Solutions for eliminating the fish distress and possible mortality associated with such effluents would be to lower the carbon dioxide level to below 100 mg/L by aeration or pH adjustment.

scholarly journals Estimating the impact of inhibitory substances on activated sludge denitrification process

2019 ◽  
Vol 14 (4) ◽  
pp. 863-871 ◽  
Author(s):  
Kati Klein ◽  
Taavo Tenno
Keyword(s):  
Standard Deviation ◽  
Oxygen Uptake ◽  
Activated Sludge ◽  
Process Efficiency ◽  
Sludge Treatment ◽  
Conventional Activated Sludge ◽  
Uptake Rates ◽  
Relative Standard ◽  
The Impact ◽  
Denitrification Process

Abstract Industrial wastewater frequently contains substances which inhibit activated sludge treatment processes. Inhibitory characteristics of different substances are usually evaluated based on testing the impact of respective substance on activated sludge nitrification or oxygen uptake rates. However, denitrification is always before aerobic processes in conventional activated sludge treatment plants and thereby more exposed to inhibitory compounds. There is no easily applicable and validated method available for determination of denitrification process efficiency and inhibition. In this study, a method for evaluation of inhibition on the activated sludge denitrification process was developed and validated using 3,5-dichlorophenol (3,5-DCP) as a model inhibitory compound and additionally controlled with real wastewater produced in the shale oil industry. Average IC50 value (5.5 ± 2.2 mg L−1) for 3,5-DCP showed that denitrifiers were less sensitive than nitrifiers (IC50 = 2.9 ± 0.7 mg L−1) and more sensitive than aerobic heterotrophs (IC50 = 7.2 ± 2.4 mg L−1). Methodological aspects like accumulation of nitrite nitrogen, acclimatization of biomass and technical issues were discussed. Achieved validation characteristics were similar with ISO Standards estimating activated sludge nitrification and oxygen uptake rates, which proves the reliability of the method: standard deviation, 95.4% confidence level, relative standard deviation were calculated to be 2.2 mg L−1, 1.2 … 9.8 mg L−1 and 39.2%, respectively.

Removal of tetracyclines from swine manure at full-scale activated sludge treatment plants

2015 ◽  
Vol 36 (15) ◽  
pp. 1966-1973 ◽  
Author(s):  
Nuria Montes ◽  
Marta Otero ◽  
Ricardo N. Coimbra ◽  
Rosa Méndez ◽  
Javier Martín-Villacorta
Keyword(s):  
Activated Sludge ◽  
Swine Manure ◽  
Full Scale ◽  
Sludge Treatment

Methane Emissions from Aerated Zones in a Full-Scale Nitrifying Activated Sludge Treatment Plant

2013 ◽  
Vol 225 (1) ◽  
Author(s):  
Amina Aboobakar ◽  
Mark Jones ◽  
Peter Vale ◽  
Elise Cartmell ◽  
Gabriela Dotro
Keyword(s):  
Activated Sludge ◽  
Treatment Plant ◽  
Methane Emissions ◽  
Full Scale ◽  
Sludge Treatment

Full-scale control of Mycolata foam by FEX-120 addition

2010 ◽  
Vol 61 (10) ◽  
pp. 2443-2450 ◽  
Author(s):  
C. Kragelund ◽  
B. Nilsson ◽  
K. Eskilsson ◽  
A. M. Bøgh ◽  
P. H. Nielsen
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Wastewater Treatment Plant ◽  
No Reduction ◽  
Treatment Plant ◽  
Full Scale ◽  
Filamentous Bacteria ◽  
Gram Positive ◽  
Sludge Treatment ◽  
Scale Control

Foaming incidents in activated sludge treatment plants are a worldwide problem and occur on a regular basis in both municipal and industrial activated sludge treatment plants. Foaming is most often caused by excessive growth of filamentous bacteria, especially the gram-positive ones affiliated within the Actinobacteria, e.g. the branched Mycolata or CandidatusMicrothrix parvicella. Previous studies have shown that populations of Microthrix can be controlled by addition of certain polyaluminium compounds, but until now no effective chemicals have been identified to control other important foam formers such as the Mycolata. A new chemical (FilamentEx, FEX-120) was tested in full-scale in a Swedish wastewater treatment plant (WWTP) with immense foaming problems. In total, three different dosing events were carried out for more than 1 year. After only 8–17 weeks in each period, all foam had disappeared, and dosing of FEX-120 was stopped. Another 11 full-scale WWTPs in different countries were treated with FEX-120 because of severe Mycolata foaming on process tanks. In nine out of 11 plants, where the causative organisms were Gordonia or Skermania, a significant reduction of foam up to 100% was observed after treatment for approx. 10 weeks. In two WWTPs with unknown Mycolata organisms, no reduction was observed.

Sign in / Sign up

Export Citation Format

Share Document