Biosolids odor reduction by solids inventory management in the secondary activated sludge treatment system

A wastewater treatment plant consists of unit processes designed to achieve specific waste reduction goals. Offensive odors associated with these treatment processes are a constant source of public complaints. The purpose of this study was to statistically determine the process parameters that influence the formation of volatile sulfur compounds (VSCs) in the secondary treatment system. A statistical model was developed to relate the process parameters to the formation of VSCs in this system. The model established that F/M ratio, sludge blanket depth and SSV60 were the dominant process parameters that influenced the formation of VSCs in the secondary sedimentation basin. This model provides a useful tool for plant engineers to predict and control the VSC formation in a secondary activated sludge treatment system.

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

Water Science & Technology ◽

10.2166/wst.2000.0032 ◽

2000 ◽

Vol 41 (1) ◽

pp. 223-230 ◽

Cited By ~ 12

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.

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Investigations on Activated Sludge Microfauna and Treatment Plant Disfunctions

Water Science & Technology ◽

10.2166/wst.1992.0777 ◽

1992 ◽

Vol 26 (9-11) ◽

pp. 2519-2522 ◽

Cited By ~ 1

Author(s):

M. Cossignani ◽

L. Cingolani ◽

L. Giacché ◽

R. Miliani

Keyword(s):

Activated Sludge ◽

Process Parameters ◽

Treatment Plant ◽

Factorial Analysis ◽

Sludge Treatment ◽

Bod Removal

Factorial analysis was applied to data from a series of 24 samples collected in an activated sludge treatment plant from October 1990 to April 1991. Relationships between process parameters and protozoans suggested that Epistylis plicatilis aboundance is related to the best conditions of BOD removal. Moreover the presence of Litonotus fasciola related to a poor floc settling.

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Removal and inactivation of cryptosporidium oocysts by activated sludge treatment and anaerobic digestion

Water Science & Technology ◽

10.2166/wst.1995.0572 ◽

1995 ◽

Vol 31 (5-6) ◽

pp. 97-104 ◽

Cited By ~ 5

Author(s):

K. L. Stadterman ◽

A. M. Sninsky ◽

J. L. Sykora ◽

W. Jakubowskii

Keyword(s):

Wastewater Treatment ◽

Anaerobic Digestion ◽

Activated Sludge ◽

Sewage Treatment ◽

Treatment Plant ◽

Sludge Treatment ◽

Treatment Processes ◽

Secondary Effluents ◽

Immunofluorescent Technique ◽

Cryptosporidium Parvum Oocysts

To determine the fate of Cryptosporidium parvum oocysts during wastewater treatment, a model of an activated sludge treatment plant was designed with a flow of 17 ml/min and a detention time of 6 hours. Samples of raw sewage were seeded with oocysts and primary and secondary effluents were analyzed for C. parvum using an immunofluorescent technique. To compare removal efficiencies of oocysts by various wastewater treatment processes, raw sewage, activated sludge, trickling filter and biodisc effluents were seeded with oocysts and settled for 2 hr and for the respective detention times. Sludge produced by a wastewater treatment plant and anaerobically digested at 37° C in a laboratory digester was also seeded with C. parvum oocysts. Oocyst inactivation was measured by excystation and direct counts. Removal of oocysts in primary and secondary sedimentation averaged 83.4% and 90.7% respectively. The total oocyst removal in sewage treatment averaged 98.6%. In comparison with other treatment processes, activated sludge had the maximum oocyst removal efficiency at 92%. The anaerobic digestion process inactivated 90% of the oocysts within four hours of exposure. 99.9% of the oocysts were eliminated by anaerobic digestion after 24 hours. This demonstrates that the activated sludge process and anaerobic digestion can be effective for the removal and inactivation of C. parvum oocysts.

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Behaviour of Mechanically Blended Return-Sludge in Absence of Substrate

Water Quality Research Journal ◽

10.2166/wqrj.1970.004 ◽

1970 ◽

Vol 5 (1) ◽

pp. 34-54

Author(s):

Shyam D. Bokil ◽

Jatinder K. Bewtra

Keyword(s):

Activated Sludge ◽

Suspended Solids ◽

Treatment Plant ◽

Aeration Rate ◽

Batch Experiments ◽

Sludge Treatment ◽

Waring Blender ◽

Settling Characteristics

Abstract Nine sets of batch experiments, each of ten to twelve days duration, were conducted in the laboratory on return-sludge samples collected from activated sludge treatment plant at Windsor. The thickened sludge samples were blended daily in a waring blender and were continuously aerated in twelve-litres capacity jars. Parallel runs were made on control sludge samples which were not blended. Amongst the parameters varied were the speed and frequency of blending and the aeration rate. The effects of these variables on progressive bio-degradation of volatile suspended solids and the settling characteristics of the sludge were determined. Blended sludge showed significant improvement in the rate of bio-degradation and its settling characteristics as compared to the control unblended sludge

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Deemulsification of Water-in-Oil Emulsion with Sludges

Water Quality Research Journal ◽

10.2166/wqrj.1987.034 ◽

1987 ◽

Vol 22 (3) ◽

pp. 437-443 ◽

Cited By ~ 5

Author(s):

N. Kosaric ◽

Z. Duvnjak

Keyword(s):

Activated Sludge ◽

Room Temperature ◽

Petroleum Refinery ◽

Treatment Plant ◽

Granular Sludge ◽

Activated Sludge Process ◽

Sludge Treatment ◽

Oil Emulsion ◽

Water In Oil Emulsion ◽

Aerobic Sludge

Abstract Aerobic sludge from a municipal activated sludge treatment plant, sludge from a conventional municipal anaerobic digester, aerobic sludge from an activated sludge process of a petroleum refinery, and granular sludge from an upflow sludge blanket reactor (USBR) were tested in the deemulsification of a water-in-oil emulsion. All sludges except the last one, showed a good deemulsification capability and could he used for a partial deemulsification of such emulsions. The rate and degree of the deemulsifications increased with an increase in sludge concentrations. The deemulsifications were faster at 85°C and required smaller amounts of sludge than in the case of the deemulsifications at room temperature. An extended stirring (up to a certain limit) in the course of the dispersion of sludge emulsion helped the deemulsification. Too vigorous agitation had an adverse effect. The deemulsification effect of sludge became less visible with an increase in the dilution of emulsion which caused an increase in its spontaneous deemulsification.

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System Identification and Control of the Activated Sludge Process by Use of a Statistical Model

Water Science & Technology ◽

10.2166/wst.1989.0316 ◽

1989 ◽

Vol 21 (10-11) ◽

pp. 1161-1172 ◽

Cited By ~ 8

Author(s):

M. Hiraoka ◽

K. Tsumura

Keyword(s):

Control System ◽

System Identification ◽

Statistical Model ◽

Activated Sludge ◽

Sewage Treatment Plant ◽

Treatment Plant ◽

Ar Model ◽

Diurnal Changes ◽

Activated Sludge Process ◽

And Control

The authors have been developing a hierarchical control system for the activated sludge process which consists of an upper level system controlling long-term seasonal variations, a control system of intermediate level aiming at optimization of the process and a control system of lower level controlling diurnal changes or hourly fluctuations. The control system using the multi-variable statistical model is one of the most appropriate control systems based on the modern control theory, for applying the lower level control of the activated sludge process. This paper introduces our efforts for developing the reliable data acquisition system, the control experiments applying the AR-model, one of the statistical models which were conducted at a pilot plant and present studies on the system identification and control at a field sewage treatment plant.

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Solids Concentrations in a Treatment Plant Effluent

Water Science & Technology ◽

10.2166/wst.1992.0783 ◽

1992 ◽

Vol 26 (9-11) ◽

pp. 2543-2546

Author(s):

M. Defrain ◽

F. Schmidt

Keyword(s):

Waste Water ◽

Activated Sludge ◽

Federal Republic ◽

Treatment Plant ◽

Analysis Procedure ◽

Process Water ◽

Federal Republic Of Germany ◽

Output Variable ◽

Sludge Treatment ◽

Sewerage Network

In the calculations customarily used to dimension nitrification and denitrification plants in the Federal Republic of Germany, solids in the influent of the biological stage represent a significant output variable. Numerous modified methods based on nationally and internationally standardized analysis procedures are available to determine solids concentrations in waste-water. Tests showed that different values are measured depending on the method of analysis employed. Harmonization of the analysis procedure is advisable to ensure comparable conditions for the calculation of activated sludge tank volumes. The solids reaching a treatment plant originate from two main sources. Filterable materials are passed to the treatment plant via the preceding sewerage network with its industrial and commercial users, but are also carried by process water from sludge treatment. The influence of process water on wastewater composition is illustrated by reference to the Wuppertal-Buchenhofen treatment plant.

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