scholarly journals An Integrated Approach to the Biological Reactor–Sedimentation Tank System

Resources ◽  
2019 ◽  
Vol 8 (2) ◽  
pp. 94 ◽  
Author(s):  
Serena Conserva ◽  
Fabio Tatti ◽  
Vincenzo Torretta ◽  
Navarro Ferronato ◽  
Paolo Viotti
Keyword(s):  
Activated Sludge ◽  
Biological Process ◽  
Wastewater Treatment Plants ◽  
Great Influence ◽  
Integrated Approach ◽  
Biological Processes ◽  
Sludge Characteristics ◽  
Activated Sludge System ◽  
Proposed Model ◽  
Tank System

Secondary clarifiers are demanded to separate solids created in activated sludge biological processes to achieve both a clarified effluent and to manage the biological processes itself. Indeed, the biological process may influence the sludge characteristics, and conversely, the settling efficiency of the sedimentation basin plays an important role on the biological process in the activated sludge system. The proposed model represents a tool for better addressing the design and management of activated sludge system in wastewater treatment plants. The aim is to develop a numerical model which takes into account both the conditions in the biological reactor and the sludge characteristics coupled to the hydrodynamic behavior of a clarifier tank. The obtained results show that the different conditions in the reactor exert a great influence on the sedimentation efficiency.

The effect of flow equalisation and prefermentation on the sludge production and sludge characteristics in a BNR plant

2008 ◽  
Vol 57 (12) ◽  
pp. 2023-2029 ◽  
Author(s):  
A. Mikola ◽  
J. Rautiainen ◽  
H. Kiuru
Keyword(s):  
Activated Sludge ◽  
Suspended Solids ◽  
Biological Process ◽  
Diurnal Variations ◽  
Full Scale ◽  
Waste Activated Sludge ◽  
Sludge Characteristics ◽  
Stable Conditions ◽  
Sludge Production ◽  
Sludge Concentration

A full-scale study investigated the influence of diurnal flow equalisation and prefermentation on the characteristics of sludge. The diurnal variations in the sludge concentration and the level of sludge blanket in the secondary clarifiers were evened out significantly with the use of an equalization basin. Stable conditions in the aeration basin and in the secondary clarifiers contributed to the improvements in the performance of the BNR plant. A decrease in the waste activated sludge production and an improvement in the settleability were also observed. The low WAS yield was attributed to the low yield COD compounds produced by the prefermentation, longer sludge age and constant conditions obtained by the flow equalisation. Some evidence was found that good settling properties would be related to the amount of suspended solids fed to the biological process as well as to the good performance of the biological process.

Apport des mesures respirométriques à la gestion d'une station d'épuration à boues activées

1998 ◽  
Vol 25 (2) ◽  
pp. 353-359
Author(s):  
B Weiss ◽  
N Roche ◽  
O Potier ◽  
M -N Pons ◽  
S Gauthier ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Oxygen Uptake ◽  
Activated Sludge ◽  
Control Strategy ◽  
Biological Process ◽  
Wastewater Treatment Plants ◽  
Good Control ◽  
Biological Sensors ◽  
Uptake Rates ◽  
First Results

New regulations for wastewater treatment that will insure greater reliability of the wastewater treatment plants are being established, that is to say in the case of an activated sludge plant, a better control of the biological process. The use of biological sensors would appear to increase the reliability of the plants by allowing the assessment of some characteristic variables of the process and by detecting as quickly as possible the influx of a toxin that is able to inhibit the biomass. We created a biosensor that measures oxygen uptake rates. According to the first results obtained, the data could lead to a good control strategy of the activated sludge process.Key words: wastewater treatment, activated sludge, respirometry, control.

Comparison between hybrid moving bed biofilm reactor and activated sludge system: a pilot plant experiment

2010 ◽  
Vol 61 (4) ◽  
pp. 891-902 ◽  
Author(s):  
Daniele Di Trapani ◽  
Giorgio Mannina ◽  
Michele Torregrossa ◽  
Gaspare Viviani
Keyword(s):  
Activated Sludge ◽  
Pilot Plant ◽  
Wastewater Treatment Plants ◽  
Biofilm Reactor ◽  
Additional Contribution ◽  
Moving Bed Biofilm Reactor ◽  
Moving Bed ◽  
Activated Sludge System ◽  
Hydraulic Load ◽  
Plant Experiment

The paper presents the comparison between the traditional activated sludge system (AS) and a hybrid moving bed biofilm reactor (HMBBR). In particular, an experimental campaign has been carried out at the WWTP in Palermo (Italy), on a pilot plant consisting of two pre-anoxic schemes. The aerated tank of the HMBBR line was filled with suspended carriers (AnoxKaldnes™ K1), with a 30% filling ratio. The hydraulic load of the HMBBR line was increased up to two times the AS one. Further, in order to distinguish the additional contribution of the attached biomass for the HMBBR system, in the two lines the Mixed Liquor Suspended Solids (MLSS) was maintained as equal as possible. The monitoring period lasted three months during which several parameters were monitored. The obtained results showed a good treatment ability of the HMBBR system, referring to the organic matter removal as well as to the ammonium removal. In particular, in spite of the increase of the hydraulic load for the HMBBR line, the two systems showed a similar performance in terms of both organic and nitrogen removal. The results demonstrate the higher treatment capacity of the HMBBR addressing such system as an effective technology for the upgrading of overloaded wastewater treatment plants.

scholarly journals Sulphide Biooxidation in Activated Sludge Diffusion Process: Microbiological and Biochemical Effects

Proceedings ◽  
2018 ◽  
Vol 2 (11) ◽  
pp. 646 ◽  
Author(s):  
Massimo Blonda ◽  
Angelantonio Calabrese ◽  
Raffaele Palumbo ◽  
Elvira Giorgio
Keyword(s):  
Activated Sludge ◽  
Wastewater Treatment Plants ◽  
Batch Reactors ◽  
Biological Processes ◽  
Sequencing Batch Reactors ◽  
Diffusion Test ◽  
Biochemical Activity ◽  
Sludge Flocs ◽  
Biochemical Effects ◽  
Odorous Compound

Sulphide was adopted as odorous compound in a simulation of AS Diffusion, an interesting process to treat odors at wastewater treatment plants by diffusing odorous air into aerobic basins. Its behaviour were experimentally evaluated along with its effects on the biomass and the biological processes supposed by some author in an AS diffusion test. Two bench scale sequencing batch reactors (SBRs) were fed in parallel on real primary sewage and monitored after adding increasing concentrations of sulphide to one of them. In this reactor, an average sulphide removal of 94% was measured. Microbial biochemical activity and composition did not show relevant variations after the addition of sulphide, and the good features of activated sludge flocs were maintained also in terms of sludge settleability.

scholarly journals Effect of Aluminium Salt Dosing on Activated Sludge Settleability Indicators: A New Settleability Model Development

Water ◽  
2019 ◽  
Vol 11 (1) ◽  
pp. 179 ◽  
Author(s):  
Peter Ojo ◽  
Augustine Ifelebuegu
Keyword(s):  
Activated Sludge ◽  
Wastewater Treatment Plants ◽  
Model Development ◽  
Chemical Precipitation ◽  
Significant Rise ◽  
Volume Index ◽  
Engineering Practice ◽  
Proposed Model ◽  
The Impact ◽  
Sludge Settleability

There has been a significant rise in the use of aluminium salts (Al3+) for the chemical precipitation of phosphates in wastewater treatment plants due to growing stricter regulatory requirements for wastewater effluent release to the environment. The modelling of the settleability of the resultant Al3+ sludge in present engineering practice for design and optimisation are still based on conventional sludge settleability models. This paper describes a novel activated sludge settleability model which is designed to analyse the effects of Al3+ dosing on activated sludge settleability indicators, zone settling velocity (ZSV), and stirred specific volume index (SSVI). The impact of Al3+ dosing concentrations on ZSV and SSVI of full scale activated sludge plant were analysed in the laboratory over a three years’ period and the exponential form of the Vesilind equation was optimised and validated to include alum chemical dosing parameters. The proposed model equation was found to effectively describe the settleability of Al3+ dosed sludge for dosing concentrations range of 0 to 100 mg/L.

Influence of Oxic and Anoxic Mixing Zones in Compartment Systems on Substrate Removal and Sludge Characteristics in Activated Sludge Plants

1987 ◽  
Vol 19 (5-6) ◽  
pp. 897-910 ◽  
Author(s):  
H. Hoffman
Keyword(s):  
Activated Sludge ◽  
Mixed System ◽  
Mixing Zone ◽  
Cascade System ◽  
Compartment System ◽  
Sludge Characteristics ◽  
Substrate Removal ◽  
Volume Load ◽  
Activated Sludge System ◽  
Solids Concentration

During a research program the influence of activated sludge compartment systems with and without anoxic mixing zone on the efficiency of the system and the settleability and dewatering characteristics of the activated sludge was tested. COD-load, number and volume of the compartments and the mixing zones were varied. Experiments were carried out with two pilot plants, a compartment system and a totally mixed system. The tests clearly indicate that a four-stage cascade system with a BOD-load of about 1.0 kg/(m3.d) could improve settleability and dewatering characteristics, but bulking sludge could not be avoided. Using a nonaerated upstream zone with a volume load of 4.0 kg/(m3.d)the settling properties in the compartment system(total BOD-load 1.0 kg/(m3.d)) could be improved to such an extent that the formation of bulking sludge was prevented. Better settleability leads to the higher solids concentration in the cascade system and to a lower sludge load. Therefore lower BOD-outflow-concentrations and higher efficiency of the activated sludge system were available.

Oxidation Ditch

2018 ◽  
Author(s):  
Gede H Cahyana
Keyword(s):  
Activated Sludge ◽  
Special Form ◽  
Oxidation Ditch ◽  
End Point ◽  
Activated Sludge System

As a part of activated sludge system, oxidation ditch has a special form like a canal without end point. Rotor is used to diffuse oxygen from air to the water.

Sign in / Sign up

Export Citation Format

Share Document