Assessing effluent fluoride concentrations following physicochemical wastewater treatment

1992 ◽  
Vol 19 (4) ◽  
pp. 649-659 ◽  
Author(s):  
R. Gehr ◽  
R. Leduc
Keyword(s):  
Drinking Water ◽  
Wastewater Treatment ◽  
Fluoride Concentration ◽  
Treatment Plant ◽  
Full Scale ◽  
Untreated Wastewater ◽  
Balance Analysis ◽  
Full Scale Tests ◽  
St Lawrence River ◽  
Raw Wastewater

The anticipated fluoride concentrations in untreated wastewater, as well as their removal during physicochemical treatment, were determined in order to assess potential risks to the aquatic ecosystem of the St. Lawrence River due to proposed fluoridation of Montreal's drinking water. Monitoring of the raw wastewater yielded average daily fluoride concentrations of 0.22–0.58 mg/L, but discrete sample concentrations ranged from 0.20 to 1.11 mg/L. This indicates that significant massive point discharges occur in the Montreal Urban Community (MUC) sewer system. Jar tests suggest that no precipitation of fluoride would occur following ferric chloride and polyelectrolyte addition at doses similar to those used on the full-scale wastewater treatment plant. This is confirmed by thermodynamic analysis of the solubility of various fluoride species. Full-scale tests, conducted by applying a continuous fluoride dose to the plant influent, confirmed that no removal would result from the treatment process. However, the plant did dampen the shock loads of fluoride from industrial sources. The predicted average raw wastewater fluoride concentration, including ground water and unidentified industrial discharges, was calculated to be 0.83 mg/L. Unidentified sources contribute 132 kg/d (~ 40% of the total). The average fluoride flux in the St. Lawrence River, as a result of fluoridation of the drinking water, would increase by 1.2%. Key words: fluoridation, physicochemical wastewater treatment, St. Lawrence River, mass balance analysis.

Boosting nitrification with the BABE technology

2005 ◽  
Vol 52 (4) ◽  
pp. 63-70 ◽  
Author(s):  
D.H.J.G. Berends ◽  
S. Salem ◽  
H.F. van der Roest ◽  
M.C.M. van Loosdrecht
Keyword(s):  
Wastewater Treatment ◽  
Wastewater Treatment Plants ◽  
Low Cost ◽  
Treatment Plant ◽  
Full Scale ◽  
Nitrifying Bacteria ◽  
Stable Operation ◽  
Main Process ◽  
Model Studies ◽  
Full Scale Tests

Over the past years there has been a growing interest for compact, simple, low cost and robust technologies to upgrade wastewater treatment plants for nitrogen removal. The BABE (Bio Augmentation Batch Enhanced) technology is such a new concept. This patented system for biological treatment of sludge liquor – the effluent produced from digested sludge – uses a new principle, boosting the nitrifying bacteria in a side stream in such a way that the activated sludge in the main process is augmented. This augmentation increases the nitrification capacity of the wastewater treatment plant (wwtp). Experiments on a practical scale have demonstrated the effective and stable operation of the BABE technology. Model studies supported by the results of the full-scale tests showed that the technology can be applied in several situations, i.e. 1) introducing nitrification at high loaded wwtps; 2) enhancing nitrification at wwtps with incomplete nitrification; 3) enlarging denitrification at wwtps with complete nitrification. Most likely this year a full-scale application will be realized in the Netherlands at a wwtp with insufficient nitrification throughout the year.

Modelling the performance of anaerobic wastewater stabilization ponds

1995 ◽  
Vol 31 (12) ◽  
pp. 171-183 ◽  
Author(s):  
M. M. Saqqar ◽  
M. B. Pescod
Keyword(s):  
Wastewater Treatment ◽  
Water Temperature ◽  
Removal Efficiency ◽  
Wastewater Treatment Plant ◽  
Suspended Solids ◽  
Treatment Plant ◽  
Pond Water ◽  
Removal Efficiencies ◽  
Wastewater Stabilization Ponds ◽  
Raw Wastewater

The performance of the primary anaerobic pond at the Alsamra Wastewater Treatment Plant in Jordan was monitored over 48 months. Overall averages for the removal efficiencies of BOD5, COD and suspended solids were 53%, 53% and 74%, respectively. An improvement in removal efficiency with increase in pond water temperature was demonstrated. A model, which takes into account the variability of raw wastewater at different locations, has been developed to describe the performance of a primary anaerobic pond in terms of a settleability ratio for the raw wastewater. The model has been verified by illustrating the high correlation between actual and predicted pond performance.

Evaluating the treatment performance of a full scale Activated Sludge Plant in Islamabad, Pakistan

2012 ◽  
Vol 7 (1) ◽  
Author(s):  
S. S. Fatima ◽  
S. Jamal Khan
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Wastewater Treatment Plant ◽  
Suspended Solids ◽  
Treatment Plant ◽  
Oxygen Demand ◽  
Full Scale ◽  
Operational Parameter ◽  
Mixed Liquor ◽  
Treatment Performance

In this study, the performance of wastewater treatment plant located at sector I-9 Islamabad, Pakistan, was evaluated. This full scale domestic wastewater treatment plant is based on conventional activated sludge process. The parameters which were monitored regularly included total suspended solids (TSS), mixed liquor suspended solids (MLSS), mixed liquor volatile suspended solids (MLVSS), biological oxygen demand (BOD), and chemical oxygen demand (COD). It was found that the biological degradation efficiency of the plant was below the desired levels in terms of COD and BOD. Also the plant operators were not maintaining consistent sludge retention time (SRT). Abrupt discharge of MLSS through the Surplus Activated sludge (SAS) pump was the main reason for the low MLSS in the aeration tank and consequently low treatment performance. In this study the SRT was optimized based on desired MLSS concentration between 3,000–3,500 mg/L and required performance in terms of BOD, COD and TSS. This study revealed that SRT is a very important operational parameter and its knowledge and correct implementation by the plant operators should be mandatory.

Enhancing nitrogen removal efficiency in a dyestuff wastewater treatment plant with the IFFAS process: the pilot-scale and full-scale studies

2017 ◽  
Vol 77 (1) ◽  
pp. 70-78 ◽  
Author(s):  
Yanjun Mao ◽  
Xie Quan ◽  
Huimin Zhao ◽  
Yaobin Zhang ◽  
Shuo Chen ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Removal Efficiency ◽  
Nitrogen Removal ◽  
Treatment Plant ◽  
Oxygen Demand ◽  
Pilot Scale ◽  
Full Scale ◽  
Nitrification And Denitrification ◽  
Dyestuff Wastewater

Abstract The activated sludge (AS) process is widely applied in dyestuff wastewater treatment plants (WWTPs); however, the nitrogen removal efficiency is relatively low and the effluent does not meet the indirect discharge standards before being discharged into the industrial park's WWTP. Hence it is necessary to upgrade the WWTP with more advanced technologies. Moving bed biofilm processes with suspended carriers in an aerobic tank are promising methods due to enhanced nitrification and denitrification. Herein, a pilot-scale integrated free-floating biofilm and activated sludge (IFFAS) process was employed to investigate the feasibility of enhancing nitrogen removal efficiency at different hydraulic retention times (HRTs). The results showed that the effluent chemical oxygen demand (COD), ammonium nitrate (NH4+-N) and total nitrogen (TN) concentrations of the IFFAS process were significantly lower than those of the AS process, and could meet the indirect discharge standards. PCR-DGGE and FISH results indicated that more nitrifiers and denitrifiers co-existed in the IFFAS system, promoting simultaneous nitrification and denitrification. Based on the pilot results, the IFFAS process was used to upgrade the full-scale AS process, and the effluent COD, NH4+-N and TN of the IFFAS process were 91–291 mg/L, 10.6–28.7 mg/L and 18.9–48.6 mg/L, stably meeting the indirect discharge standards and demonstrating the advantages of IFFAS in dyestuff wastewater treatment.

Upgrading of a small wastewater treatment plant in a cold climate region using a moving bed biofilm reactor (MBBR) system

2000 ◽  
Vol 41 (1) ◽  
pp. 177-185 ◽  
Author(s):  
G. Andreottola ◽  
P. Foladori ◽  
M. Ragazzi
Keyword(s):  
Wastewater Treatment ◽  
Wastewater Treatment Plant ◽  
Treatment Plant ◽  
Internal Surface ◽  
Full Scale ◽  
Biofilm Reactor ◽  
Cold Climate ◽  
Moving Bed Biofilm Reactor ◽  
Moving Bed ◽  
North East

The aim of this study was to evaluate the performance of a full-scale upgrading of an existing RBC wastewater treatment plant with a MBBR (Moving Bed Biofilm Reactor) system, installed in a tank previously used for sludge aerobic digestion. The full-scale plant is located in a mountain resort in the North-East of Italy. Due to the fact that the people varied during the year's seasons (2000 resident people and 2000 tourists) the RBC system was insufficient to meet the effluent standards. The MBBR applied system consists of the FLOCOR-RMP®plastic media with a specific surface area of about 160 m2/m3 (internal surface only). Nitrogen and carbon removal from wastewater was investigated over a 1-year period, with two different plant lay-outs: one-stage (only MBBR) and two stage system (MBBR and rotating biological contactors in series). The systems have been operated at low temperature (5–15°C). 50% of the MBBR volume (V=79 m3) was filled. The organic and ammonium loads were in the average 7.9 gCOD m−2 d−1 and 0.9 g NH4−N m−2 d−1. Typical carbon and nitrogen removals in MBBR at temperature lower than 8°C were respectively 73% and 72%.

scholarly journals Niche Differentiation among Three Closely RelatedCompetibacteraceaeClades at a Full-Scale Activated Sludge Wastewater Treatment Plant and Putative Linkages to Process Performance

2018 ◽  
Vol 85 (5) ◽  
Author(s):  
Veronica R. Brand ◽  
Laurel D. Crosby ◽  
Craig S. Criddle
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Wastewater Treatment Plant ◽  
Treatment Plant ◽  
Niche Differentiation ◽  
Full Scale ◽  
Pure Oxygen ◽  
Operational Parameters ◽  
Metabolic Potential ◽  
Operational Conditions

ABSTRACTMultiple clades within a microbial taxon often coexist within natural and engineered environments. Because closely related clades have similar metabolic potential, it is unclear how diversity is sustained and what factors drive niche differentiation. In this study, we retrieved three near-complete Competibacter lineage genomes from activated sludge metagenomes at a full-scale pure oxygen activated sludge wastewater treatment plant. The three genomes represent unique taxa within theCompetibacteraceae. A comparison of the genomes revealed differences in capacity for exopolysaccharide (EPS) biosynthesis, glucose fermentation to lactate, and motility. Using quantitative PCR (qPCR), we monitored these clades over a 2-year period. The clade possessing genes for motility and lacking genes for EPS biosynthesis (CPB_P15) was dominant during periods of suspended solids in the effluent. Further analysis of operational parameters indicate that the dominance of the CPB_P15 clade is associated with low-return activated sludge recycle rates and low wasting rates, conditions that maintain relatively high levels of biomass within the system.IMPORTANCEMembers of the Competibacter lineage are relevant in biotechnology as glycogen-accumulating organisms (GAOs). Here, we document the presence of threeCompetibacteraceaeclades in a full-scale activated sludge wastewater treatment plant and their linkage to specific operational conditions. We find evidence for niche differentiation among the three clades with temporal variability in clade dominance that correlates with operational changes at the treatment plant. Specifically, we observe episodic dominance of a likely motile clade during periods of elevated effluent turbidity, as well as episodic dominance of closely related nonmotile clades that likely enhance floc formation during periods of low effluent turbidity.

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