What to do after nutrient removal?

2001 ◽  
Vol 44 (1) ◽  
pp. 129-135 ◽  
Author(s):  
Jaap H.J.M. van der Graaf

In the Netherlands, interest in advanced treatment is increasing now that almost all wastewater treatment plants apply full biological treatment and nutrient removal. The resulting effluents have an excellent quality which can be improved further by applying advanced treatment processes like flocculating filtration, membrane filtration, UV or activated carbon, and others. The treated effluent can be re-used for various purposes, as process water, household water, urban water, for groundwater suppletion and drinking water. Nowadays many applications are investigated. In order to confirm the applicability pilot test investigations are done at various WWTPs. The results are promising; the cost estimations show increasing prospects. This will finally lead to the maturity of the advanced treatment. It will certainly contribute to a more sustainable water cycle.

2014 ◽  
Vol 71 (3) ◽  
pp. 337-342 ◽  
Author(s):  
Shanel M. Raney ◽  
M. Catherine Eimers

Long-term trends (1975–2010) in total phosphorus (TP) concentrations were evaluated at 113 stream stations across southern Ontario. Declines in TP were evident at the majority of sites (68%), including those both with (n = 49) and without (n = 64) upstream municipal wastewater treatment plants (MWWTP). Although declines in TP at stream stations downstream of MWWTPs may be attributed to improvements in P removal from treated effluent, declines at the remaining streams must be attributed to other causes. During the same time period, increases in chloride (Cl−) were observed at almost all (95%) of the 64 MWWTP-free stations. Over the past 35 years, urban land cover has increased at the expense of agricultural land area in Ontario, with the majority of these changes occurring in southern Ontario. The coincidence of declines in TP and increases in Cl− at the 64 MWWTP-free streams suggests that the two may be related, with P-rich agricultural fields being replaced with impervious surfaces and therefore increased road salt applications.


2006 ◽  
Vol 54 (1) ◽  
pp. 237-245 ◽  
Author(s):  
T.R. Thomsen ◽  
C. Kragelund ◽  
P.H. Nielsen

Microcolony-forming bacteria closely related to the genus Aquaspirillum in the Betaproteobacteria were recently observed to be abundant in many nutrient removal wastewater treatment plants. The developed oligonucleotide probe, Aqs997, however, occasionally also targeted some filamentous bacteria in activated sludge samples when fluorescence in situ hybridization was performed. In this study, the identity, abundance, and ecophysiology of these Aqs997-positive filamentous bacteria were studied in detail. Most of the Aqs997-positive filamentous bacteria could morphologically be identified as either Eikelboom Type 1701, Type 0041/0675 or possibly Type 1851, all characterized by epiphytic growth. They were found in almost all 21 wastewater treatment plants investigated. Two morphotypes were found. Type A filaments, which seemed to be the same genotype as the microcolony-forming bacteria targeted by probe Aqs997.Type B filaments also hybridized with probe GNS941, specific for the Chloroflexi phylum, so the true identity remains unclear. Aqs997-positive filaments usually stained Gram-negative, but Gram-positive filaments were also found, stressing the difficulties in identifying bacteria from morphology and simple staining results. Studies on the ecophysiology by microautoradiography showed that Aqs997-positive filamentous bacteria did not consume acetate and glucose, while some took up butyrate, mannose, and certain amino acids. Most likely, some Aqs997-positive filamentous bacteria were able to perform full denitrification such as the Aqs997-positive microcolony-forming bacteria, and some were able to store polyhydroxyalkanoates under anaerobic conditions, potentially being glycogen accumulating organisms.


1999 ◽  
Vol 39 (5) ◽  
pp. 129-136 ◽  
Author(s):  
J. H. J. M. van der Graaf ◽  
J. F. Kramer ◽  
J. Pluim ◽  
J. de Koning ◽  
M. Weijs

In the Netherlands interest in advanced treatment is increasing now that almost all wastewater treatment plants apply full biological treatment and nutrient removal. Membrane filtration of WWTP-effluent appears to be a very promising method to remove suspended solids and, in addition, bacteria and viruses. Experiments with a pilot unit consisting of a dual media prefilter and a membrane filter, containing capillary membranes with a pore size of 0.01 μm (ultrafiltration) and working in a semi dead-end mode, gave rather promising results. A flux of 90 l/m2.h was achieved after optimizing the cleaning procedures (TMP 0.6 bar, recovery > 90%). Experiments with microfiltration (transverse flow module) based on the cross-flow principle were successful only at high cross flow velocities (flux 100 l/m2.h, TMP 0.5 bar, recovery 80%). The ultrafiltrate showed an excellent quality with the absence of suspended solids and bacteria. Finally, low costs for energy (NLG 0.02/m3 (1 NLG = 0.5 US$)) and chemicals (NLG 0.01/m3) were calculated. Further optimization will facilitate the applicability of membrane filtration in the near future.


2007 ◽  
Vol 56 (5) ◽  
pp. 9-13 ◽  
Author(s):  
F. Schwätter ◽  
C.B. Hannich ◽  
T. Nöthe ◽  
J. Oehlmann ◽  
H. Fahlenkamp

The elimination of organic trace compounds in municipal wastewater was analysed at three German wastewater treatment plants. Additionally, the effects of advanced treatment, membrane filtration, adsorption and oxidation processes were investigated. To assess the ecotoxicity of effluents, a number of tools were used: substance-specific evaluation, case studies for combined effects and risk assessment on the basis of cumulative parameters. The results of the research projects revealed that aquatic environmental risks can be reduced significantly using advanced treatment technologies for wastewater treatment plants.


1998 ◽  
Vol 37 (9) ◽  
pp. 209-217 ◽  
Author(s):  
M. C. M. van Loosdrecht ◽  
F. A. Brandse ◽  
A. C. de Vries

In the past years extensive experience has been gained in the upgrading of waste water treatment processes for efficient nutrient removal. Hereby especially the integration of denitrification and biological P-removal has been focused upon on these experiences a new process configuration (the BCFS®-process) was developed. This process is specially designed to optimise the activity of denitrifying P-removing bacteria. If the biological P-removal process needs to be supplemented an integrated ‘P-stripper’ is designed. This paper reviews the upgrading of three wastewater treatment plants by the new process.


1993 ◽  
Vol 28 (7) ◽  
pp. 55-61 ◽  
Author(s):  
Tsuyoshi Hirata ◽  
Kiyoshi Kawamura ◽  
Kazuyoshi Yano ◽  
Mitsumi Kaneko ◽  
Takeo Moniwa ◽  
...  

The removal characteristics of indigenous microorganisms in wastewater treatment unit processes were studied at five operating wastewater treatment plants. The removal efficiencies of the selected microorganisms in each unit process were dependent upon not only the systems but also the kinds of microorganisms. In almost all processes, the removal efficiencies of total coliforms were similar to or higher than those of Clostridium perfringens except for filtration processes. In the additional survey, focussed on the comparison of removal efficiencies of total coliforms, Cl. perfringens and coliphages, little difference was found between CL perfringens and coliphages. From these results, it may be suggested that CL Perfringens is an effective indicator microorganism for evaluating microorganism removal in wastewater treatment processes and systems.


1990 ◽  
Vol 22 (7-8) ◽  
pp. 53-60 ◽  
Author(s):  
B. Rabinowitz ◽  
T. D. Vassos ◽  
R. N. Dawson ◽  
W. K. Oldham

A brief review of recent developments in biological nitrogen and phosphorus removal technology is presented. Guidelines are outlined of how current understanding of these two removal mechanisms can be applied in the upgrading of existing wastewater treatment plants for biological nutrient removal. A case history dealing with the upgrading of the conventional activated sludge process located at Penticton, British Columbia, to a biological nutrient removal facility with a design flow of 18,200 m3/day (4.0 IMGD) is presented as a design example. Process components requiring major modification were the headworks, bioreactors and sludge handling facilities.


1986 ◽  
Vol 18 (7-8) ◽  
pp. 289-296
Author(s):  
C. F. Ouyang ◽  
T. J. Wan

This study investigated and compared the treatment characteristics of three different kinds of biological wastewater treatment plants (including rotating biological contactor, trickling filter and oxidation ditch) which are currently operated in Taiwan. The field investigation of this study concentrated on the following items: the performance of biological oxygen demand (BOD) and suspended solids (SS) removal; the sludge yield rate of BOD removal; the settleability of sludge solids; the properties of sludge thickening; the power consumption and land area requirement per unit volume of wastewater. Finally, based on the results of the field investigation, a comparison of the treatment characteristics of the three different biological treatment processes was evaluated.


1990 ◽  
Vol 22 (3-4) ◽  
pp. 211-216
Author(s):  
Niels Skov Olesen

In some areas of Denmark nutrient removal is required even for very small wastewater plants, that is down to 500 pe (pe = person equivalents). The goal for the removal is 80% removal of nitrogen and 90% removal of phosphorus, or in terms of concentrations: 8 mg nitrogen/l and 1.2 mg phosphorus/l. The inlet concentrations are typically 40 mg N/l and 10 mg P/l. The paper presents the results from two such plants with a capacity of 800 pe. Phosphorus removal is made by simultaneous precipitation with ferrous sulphate. Nitrogen removal is carried out using the recirculation method. Both plants were originally rotor aerated oxidation ditches. They have been extended with a denitrification reactor and a recirculation pumping station. At present both plants have been in activity for about 3 years and with satisfactory results. Average concentrations of nitrogen (summer) and phosphorus is 7 mg/l and 0.9 mg/l respectively. Nitrogen removal seems to be a practical solution on these small plants. It is,though, sensitive to temperature and highly oxidized rain water. Phosphorus removal seems to be an easily run and relatively non-sensitive technique at least when using simultaneous precipitation.


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