scholarly journals Integration of high-rate DAF technology within a municipal biofiltration plant for the treatment and thickening of backwash wastewaters

2018 ◽  
Vol 13 (4) ◽  
pp. 812-820
Author(s):  
Roche Clement ◽  
Manic Gildas ◽  
Lacroix Isabelle
Keyword(s):  
Municipal Wastewater ◽  
Cost Optimization ◽  
Treatment Plant ◽  
Water Concentration ◽  
Full Scale ◽  
High Rate ◽  
Municipal Wastewater Treatment ◽  
Design Integration ◽  
Performance Results ◽  
Direct Discharge

Abstract Industrial full-scale application of high-rate dissolved air floatation (DAF) in the municipal wastewater treatment plant (WWTP) of Grenoble (France) has highlighted outstanding performance results leading to new design-to-cost perspectives. The integration of DAF technology to treat the returns from the backwash waters of submerged biological aerated filters (BAF) (nitrification stage) has demonstrated removal efficiencies that allow further room for global process optimization. The results obtained on nitrifying BAF backwash water showed a DAF outlet water concentration of less than 25 mg.L−1 of total suspended solids at 25 m.h−1, with only polymer conditioning. Such high clarification performance allows leveraging of valuable cost optimization of global process design integration. Direct discharge from DAF's outlet into the receiving body can be implemented. Hydraulic and solid return loads can therefore be significantly reduced at the inlet of the WWTP. Moreover, floated sludge extracted from the DAF units achieved 4.4% dryness on average. The high thickening operational performance of this DAF technology is able to produce sludge directly compatible with anaerobic digestion. These full-scale results demonstrate that Suez's GreenDAF™-BWW technology in such application can leverage new rooms for design improvement for BAF treatment and total cost optimization of both the mainstream water treatment line and sludge line.

Nitrogen removal from digester supernatant via nitrite - SBR or SHARON?

2003 ◽  
Vol 48 (8) ◽  
pp. 9-18 ◽  
Author(s):  
C. Fux ◽  
K. Lange ◽  
A. Faessler ◽  
P. Huber ◽  
B. Grueniger ◽  
...  
Keyword(s):  
Municipal Wastewater ◽  
Flow Reactor ◽  
Batch Reactor ◽  
Treatment Plant ◽  
Full Scale ◽  
Municipal Wastewater Treatment ◽  
Nitrite Oxidation ◽  
High Concentrations ◽  
Nitrite Nitrate ◽  
Sharon Process

Separate biological elimination of nitrogen from the digester supernatant of a municipal wastewater treatment plant (WWTP) was investigated in pilot and full-scale plants. Denitrification mainly via nitrite was achieved in a sequencing batch reactor (SBR) and a continuous flow reactor (CSTR or SHARON). Suppression of nitrite oxidation in the SBR was feasible at short aerobic/anaerobic intervals allowing for immediate denitrification of the produced nitrite. Nitrate production could also be stopped by exposing the biomass to anaerobic conditions for 11 days. Temporarily high concentrations (up to 80 gNH3-Nm-3) of free ammonia could not be considered as the major reason for inhibiting nitrite oxidation. In a full-scale SBR plant 90% of the nitrogen load was denitrified in a total hydraulic retention time (HRT) of 1.6 days and with a sludge age between 15 and 20 days. Ethanol and methanol were used for denitrification. The specific average substrate consumption was 2.2 gCODdosedg-1Nremoved with an effective biomass yield of 0.2 gCODbiomassg-1CODdosed. No dosing with base was required. In the SHARON process full nitrogen elimination was achieved only with a total HRT greater than 4 days at 29°C. The overall costs were estimated at €1.4 kg-1Nremoved for the SBR and €1.63 kg-1Nremoved in SHARON mode, respectively. The SHARON process is simple in operation (CSTR) but the tank volume has to be significantly greater than in SBR.

scholarly journals Genes encoding tetracycline resistance in a full-scale municipal wastewater treatment plant investigated during one year

2009 ◽  
Vol 8 (2) ◽  
pp. 247-256 ◽  
Author(s):  
Stefan Börjesson ◽  
Ann Mattsson ◽  
Per-Eric Lindgren
Keyword(s):  
Wastewater Treatment ◽  
Wastewater Treatment Plant ◽  
Municipal Wastewater ◽  
Treatment Plant ◽  
Tetracycline Resistance ◽  
Full Scale ◽  
Municipal Wastewater Treatment ◽  
Genes Encoding ◽  
Total Dna ◽  
One Year

Tetracycline-resistant bacteria and genes encoding tetracycline resistance are common in anthropogenic environments. We studied how wastewater treatment affects the prevalence and concentration of two genes, tetA and tetB, that encode resistance to tetracycline. Using real-time polymerase chain reaction (PCR) we analysed wastewater samples collected monthly for one year at eight key-sites in a full-scale municipal wastewater treatment plant (WWTP). We detected tetA and tetB at each sampling site and the concentration of both genes, expressed per wastewater volume or per total-DNA, decreased over the treatment process. The reduction of tetA and tetB was partly the result of the sedimentation process. The ratio of tetA and tetB, respectively, to total DNA was lower in or after the biological processes. Taken together our data show that tetracycline resistance genes occur throughout the WWTP, and that the concentrations are reduced under conventional operational strategies.

scholarly journals Enhancement of struvite pellets crystallization in a full-scale plant using an industrial grade magnesium product

2016 ◽  
Vol 75 (3) ◽  
pp. 609-618 ◽  
Author(s):  
D. Crutchik ◽  
N. Morales ◽  
J. R. Vázquez-Padín ◽  
J. M. Garrido
Keyword(s):  
Municipal Wastewater ◽  
High Efficiency ◽  
Treatment Plant ◽  
Full Scale ◽  
Phosphate Concentration ◽  
Phosphorus Recovery ◽  
Municipal Wastewater Treatment ◽  
Industrial Grade ◽  
Struvite Crystallization ◽  
High Level

A full-scale struvite crystallization system was operated for the treatment of the centrate obtained from the sludge anaerobic digester in a municipal wastewater treatment plant. Additionally, the feasibility of an industrial grade Mg(OH)2 as a cheap magnesium and alkali source was also investigated. The struvite crystallization plant was operated for two different periods: period I, in which an influent with low phosphate concentration (34.0 mg P·L−1) was fed to the crystallization plant; and period II, in which an influent with higher phosphate concentration (68.0 mg P·L−1) was used. A high efficiency of phosphorus recovery by struvite crystallization was obtained, even when the effluent treated had a high level of alkalinity. Phosphorus recovery percentage was around 77%, with a phosphate concentration in the effluent between 10.0 and 30.0 mg P·L−1. The experiments gained struvite pellets of 0.5–5.0 mm size. Moreover, the consumption of Mg(OH)2 was estimated at 1.5 mol Mg added·mol P recovered−1. Thus, industrial grade Mg(OH)2 can be an economical alternative as magnesium and alkali sources for struvite crystallization at industrial scale.

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