Enhanced phosphorus removal in the DAF process by flotation scum recycling for advanced treatment of municipal wastewater

2015 ◽  
Vol 72 (4) ◽  
pp. 600-607 ◽  
Author(s):  
Dong-Heui Kwak ◽  
Ki-Cheol Lee
Keyword(s):  
Removal Efficiency ◽  
Municipal Wastewater ◽  
Wastewater Treatment Plants ◽  
Advanced Treatment ◽  
Municipal Wastewater Treatment ◽  
Application Process ◽  
Additive Process ◽  
Dissolved Air Flotation ◽  
Equilibrium Control ◽  
P Removal

To remove phosphorus (P) from municipal wastewater, various types of advanced treatment processes are being actively applied. However, there is commonly a space limit in municipal wastewater treatment plants (MWTPs). For that reason, the dissolved air flotation (DAF), which is well known for small space and flexible application process, is preferred as an additive process to enhance the removal of P. A series of experiments were conducted to investigate the feasibility of flotation scum recycling for effective P removal from a MWTP using a DAF pilot plant over 1 year. The average increases in the removal efficiencies due to flotation scum recycling were 22.6% for total phosphorus (T-P) and 18.3% for PO4-P. A higher removal efficiency of T-P was induced by recycling the flotation scum because a significant amount of Al components remained in the flotation scum. The increase in T-P removal efficiency, due to the recycling of flotation scum, shifted from the boundary of the stoichiometric precipitate to the equilibrium control region. Flotation scum recycling may contribute to improving the quality of treated water and reducing treatment costs by minimizing the coagulant dosage required.

Expenditure on the operation of municipal wastewater treatment plants for nutrient removal

2000 ◽  
Vol 41 (9) ◽  
pp. 281-289 ◽  
Author(s):  
O. Nowak
Keyword(s):  
Nutrient Removal ◽  
Municipal Wastewater ◽  
Wastewater Treatment Plants ◽  
General Scheme ◽  
Operating Costs ◽  
Municipal Wastewater Treatment ◽  
Wastewater Purification ◽  
Labour Costs ◽  
Municipal Wastewater Treatment Plants ◽  
P Removal

Operating costs of Austrian municipal treatment plants are evaluated for 1989/90 and for 1997, respectively. The results indicate that presently the expenses which can be directly connected to wastewater purification, i.e. energy and chemicals for P removal, comprise only about 20% of the total operating costs. Today, in Austria like in other EU countries, the predominating factor is “labour costs”, even at nutrient removal plants. A general scheme for estimating operating costs is presented that can be applied to WWTPs in other parts of the world. In this scheme the important factors relevant to the operating costs are integrated.

Comparison of wastewater treatment processes on the removal efficiency of organophosphate esters

2016 ◽  
Vol 74 (7) ◽  
pp. 1602-1609 ◽  
Author(s):  
Long Pang ◽  
Peijie Yang ◽  
Jihong Zhao ◽  
Hongzhong Zhang
Keyword(s):  
Wastewater Treatment ◽  
Removal Efficiency ◽  
Flame Retardants ◽  
Municipal Wastewater ◽  
Wastewater Treatment Plants ◽  
Removal Rate ◽  
Municipal Wastewater Treatment ◽  
Triphenyl Phosphate ◽  
Organophosphate Esters ◽  
Municipal Wastewater Treatment Plants

Organophosphate esters (OPs), widely used as flame retardants and plasticizers, are regarded as a class of emerging pollutants. The effluent of municipal wastewater treatment plants is generally considered to be the main contributor of OP pollution to the surface water. In this study, anoxic–oxic (AO) and University of Capetown (UCT) processes were selected to investigate the removal efficiency of OPs. The results indicated that the UCT process showed better removal efficiency than that of the AO process. For the chlorinated OPs, approximately 12.3% of tri(2-chloroethyl)phosphate and 11.8% of tri(chloropropyl)phosphate can be removed in the UCT process, which was 12% and 7.8% higher than that of the AO process. In contrast, non-chlorinated OPs, including tris(2-butoxyethyal)phosphate, triphenyl phosphate, and tributyl phosphate, were able to be removed in both processes, with the removal rate of 85.1%, 74.9%, and 29.1% in the AO process, and 88.4%, 63.6%, and 25.2% in the UCT process. Furthermore, linear correlation between the removal rate and logKow of OPs (r2 = 0.539) was observed in the AO process, indicating that OPs with high Kow value (e.g. tri(dichloropropyl)phosphate and triphenyl phosphate) are prone to be removed by adsorption on the residual activated sludge.

Enhanced denitrification with methanol at WWTP Zürich-Werdhölzli

1996 ◽  
Vol 33 (12) ◽  
pp. 117-126 ◽  
Author(s):  
I. Purtschert ◽  
H. Siegrist ◽  
W. Gujer
Keyword(s):  
Wastewater Treatment ◽  
Carbon Source ◽  
Removal Efficiency ◽  
Nitrogen Removal ◽  
Municipal Wastewater ◽  
Wastewater Treatment Plants ◽  
Treatment Plant ◽  
Yield Coefficient ◽  
Adaptation Period ◽  
Municipal Wastewater Treatment

In coordination with the EU-guidelines the large wastewater treatment plants in Switzerland have to be extended with enhanced nitrogen removal. Due to the existing plant configuration, the low COD/N ratio and dilute wastewater, denitrification supported by an external carbon source instead of extending the plant may be an interesting and cost effective solution for municipal wastewater treatment. At the wastewater treatment plant Zürich-Werdhölzli different experiments were performed with methanol addition to predenitrification from March to July 1994. The aim of this work was to evaluate the use of methanol as an alternative to plant extension to achieve a higher nitrogen removal efficiency. Therefore, two parallel denitrifying lanes were investigated, one served for methanol addition experiments and the other as a control. The effect of oxygen input into the anoxic zone due to influent, return sludge and mixing was investigated, too. The results show that nitrogen removal efficiency can be substantially increased as compared to the reference lane. The adaptation period for methanol degradation was only a few days and the process was relatively stable. Based on total nitrogen in the inflow, the average denitrification was 55% with methanol addition and 35% without methanol. The yield coefficient YCOD was 0.4 g CODX g−1 CODMe. Due to the small net growth rate of the methanol degraders the denitrification capacity is relatively low and nitrate peak loads cannot be fully denitrified. Hence, methanol as a carbon source requires more or less constant dosing. To prevent nitrate limitation, methanol addition should be controlled by the anoxic nitrate concentrations.

Occurrence and efficacy of bisphenol A (BPA) treatment in selected municipal wastewater treatment plants, Bangkok, Thailand

2015 ◽  
Vol 72 (3) ◽  
pp. 463-471 ◽  
Author(s):  
Intira Pookpoosa ◽  
Ranjna Jindal ◽  
Daisy Morknoy ◽  
Kraichat Tantrakarnapa
Keyword(s):  
Wastewater Treatment ◽  
Bisphenol A ◽  
Activated Sludge ◽  
Removal Efficiency ◽  
Municipal Wastewater ◽  
Wastewater Treatment Plants ◽  
Nutrients Removal ◽  
Municipal Wastewater Treatment ◽  
Treatment Processes ◽  
Municipal Wastewater Treatment Plants

Investigations were carried out on the occurrence and fate of bisphenol A (BPA) in five wastewater treatment plants (WWTPs) in Bangkok, namely, Rattanakosin, Chong Non Si, Din Daeng (DD), Nong Khaem and Thungkru (TK) during three sampling events between October 2013 and February 2014. Based on the results, the influent and effluent BPA concentrations ranged between 128.5 ng/L and 606.0 ng/L; and 38.7 ng/L and 270.5 ng/L, respectively. The effluent BPA concentrations of most of the five WWTPs were lower than the influent levels. TK had the highest removal efficiency in October 2013 (80.4%) and December 2013 (90.7%) and the second highest in February 2014 (69.2%). DD had the highest removal efficiency in February 2014 (91.8%). The treatment processes employed at TK and DD were vertical loop reactor activated sludge process and activated sludge with nutrients removal, respectively. Thus, these processes seem to be good for BPA degradation.

scholarly journals Technology for Upgrading the Tailwater of Municipal Sewage Treatment Plants: The Efficacy and Mechanism of Microbial Coupling for Nitrogen and Carbon Removal

Water ◽  
2021 ◽  
Vol 13 (20) ◽  
pp. 2850
Author(s):  
Yinan Zhang ◽  
Shihuan Lu ◽  
Yuxin Fang ◽  
Kexin Yang ◽  
Jiafeng Ding ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Removal Efficiency ◽  
Municipal Wastewater ◽  
Field Experiments ◽  
Wastewater Treatment Plants ◽  
Sewage Treatment ◽  
Treatment Plant ◽  
Municipal Sewage ◽  
Municipal Wastewater Treatment ◽  
Carbon Removal

The efficient removal of carbon (COD) and nitrogen (NH3-N) is vital to improving tailwater from municipal wastewater treatment plants. In this study, denitrification and decarburization bacteria with stable removal efficiencies were introduced into a membrane bioreactor (MBR) for 45 days of field experiments in a QJ Wastewater Treatment Plant (Hangzhou, China) to enhance carbon and nitrogen removal. After adding the decarbonization microorganisms into the denitrification reactor, COD removal increased from 31.2% to 80.2%, while compared to the same MBR with only denitrification microorganisms, the removal efficiency of NH3-N was greatly increased from 76.8% to 98.6%. The results of microbial analysis showed that the cooccurrence of Proteobacteria and Bacillus with high abundance and diverse bacteria, such as Chloroflexi, with autotrophic decarburization functions might account for the synchronous high removal efficiency for NH3-N and COD. This technology could provide a reference for industrial-scale wastewater treatment with the goal of simultaneous nitrogen and carbon removal.

The use of dissolved air flotation in municipal wastewater treatment

2001 ◽  
Vol 43 (8) ◽  
pp. 75-81 ◽  
Author(s):  
H. Ødegaard
Keyword(s):  
Wastewater Treatment ◽  
Municipal Wastewater ◽  
Wastewater Treatment Plants ◽  
Primary Treatment ◽  
Chemical Plants ◽  
Municipal Wastewater Treatment ◽  
Dissolved Air Flotation ◽  
Biofilm Reactors ◽  
Municipal Wastewater Treatment Plants ◽  
Dissolved Air

Flotation can be used in municipal wastewater treatment plants in different ways. Since the pollutants in wastewater to such a large extent are associated with particles, a very substantial treatment efficiency can be reached at a very small space, by using flotation in a chemical (or enhanced primary) treatment scheme. This is demonstrated in this paper with reference to results from small, prefabricated chemical plants based on flotation, which are frequently used in Norway. If used in connection with biological plants (for instance for nitrogen removal), the combination of biofilm reactors and flotation is especially advantageous because coagulation/flocculation/flotation can be placed directly after the bioreactor. Results from two such plants in Norway are presented. Recommendations with respect to design and operation of flotation plants in wastewater treatment are given.

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