Occurrence and reduction of pharmaceuticals in the water phase at Swedish wastewater treatment plants

2012 ◽  
Vol 66 (4) ◽  
pp. 783-791 ◽  
Author(s):  
P. Falås ◽  
H. R. Andersen ◽  
A. Ledin ◽  
J. la Cour Jansen

During the last decade, several screening programs for pharmaceuticals at Swedish wastewater treatment plants (WWTPs) have been conducted by research institutes, county councils, and wastewater treatment companies. In this study, influent and effluent concentrations compiled from these screening programs were used to assess the occurrence and reduction of non-antibiotic pharmaceuticals for human usage. The study is limited to full-scale WWTPs with biological treatment. Based on the data compiled, a total of 70 non-antibiotic pharmaceuticals have been detected, at concentrations ranging from a few ng/L to several μg/L, in the influent water. The influent concentrations were compared with the sale volumes and for many pharmaceuticals it was shown that only a small fraction of the amount sold reaches WWTPs as dissolved parent compounds. Pharmaceuticals with low reduction degrees at traditional WWTPs were identified. Further comparison based on the biological treatment showed lower reduction degrees for several pharmaceuticals in trickling filter plants compared with activated sludge plants with nitrogen removal.

1994 ◽  
Vol 30 (2) ◽  
pp. 165-174 ◽  
Author(s):  
Ralf Otterpohl ◽  
Thomas Rolfs ◽  
Jörg Londong

Computer simulation of activated sludge plant for nitrogen removal has become a reliable tool to predict the behaviour of the plant Models including biological phosphorus removal still require some practical experience but they should be available soon. This will offer an even wider range than today's work with nitrogen removal. One major benefit of computer simulation of wastewater treatment plants (WTP) is the optimization of operation. This can be done offline if hydrographs of a plant are collected and computer work is done with “historical” analysis. With online simulation the system is fed with hydrographs up to the actual time. Prognosis can be done from the moment of the computer work based on usual hydrographs. The work of the authors shows how accuratly a treatment plant can be described, when many parameters are measured and available as hydrographs. A very careful description of all details of the special plant is essential, requiring a flexible simulation tool. Based on the accurate simulation a wide range of operational decisions can be evaluated. It was possible to demonstrate that the overall efficiency in nitrogen removal and energy consumption of ml activated sludge plant can be improved.


2013 ◽  
Vol 68 (9) ◽  
pp. 1932-1939 ◽  
Author(s):  
Vera L. Barbosa ◽  
Richard M. Stuetz

Odours from wastewater treatment plants are comprised of a mixture of various gases with hydrogen sulphide (H2S) often being the dominant constituent. Activated sludge diffusion (ASD) as a biotreatment system for odour abatement has been conducted for over 30 years but has limited broad application due to disagreement in the literature regarding the effect that ASD may have on wastewater treatment performance. The effects of continuous H2S diffusion at 25 ppmv, with weekly peaks of approximately 100 ppmv, on H2S removal efficiency and wastewater treatment performance was evaluated over a 2-month period using an activated sludge pilot plant. H2S removal averaged 100% during diffusion at 25 ppmv, and 98.9% during the 100 ppmv peak periods. A significant increase in mixed liquor volatile suspended solids concentration (P < 0.01) was observed during H2S diffusion, which may be due to an increase in H2S-degrading microorganisms. There was no adverse effect of H2S on nitrification throughout the ASD trials. Ammonia (NH3) removal was slightly better in the test receiving H2S diffusion (87.6%) than in the control (85.4%). H2S diffusion appeared to improve robustness of the AS biomass to operational upsets.


1992 ◽  
Vol 26 (5-6) ◽  
pp. 1315-1323 ◽  
Author(s):  
H. Aspegren ◽  
B. Andersson ◽  
U. Nyberg ◽  
J. la C. Jansen

Optimization of wastewater treatment plants with extensive phosphorus and nitrogen removal is complicated. The Klagshamn wastewater treatment plant in Sweden is operated with pre-precipitation of phosphorus with ferric chloride and denitrification with methanol as carbon source. An activated sludge process, operated with pre-precipitation and denitrification with external carbon source in a compartmentalized plant, requires only small tank volumes but increases the need for proper operation and optimization. On-line nitrogen, ammonia, and TOC sensors are used for a day-to-day control and optimization while mathematical modelling is used for long term strategic planning. The on-line measurements are further used as the basis for the modelling. TOC and ammonia sensors at the influent clearly identify typical and extreme loading variations and nitrate measurements in the activated sludge tanks and the effluent shows the dynamics of the processes. These measurements provide a basis for model calibration. In combination low residuals of nitrogen, phosphorus and organic matter can be achieved.


2006 ◽  
Vol 54 (10) ◽  
pp. 79-86 ◽  
Author(s):  
G. Wandl ◽  
H. Kroiss ◽  
K. Svardal

Two-stage activated sludge plants succeed in stable treatment efficiency concerning carbon removal and nitrification with far less reactor tank volume than conventional single stage systems. In case of large treatment plants this fact is of great economic relevance. Because of the very small specific volume of these two-stage treatment plants in comparison with low loaded single-stage plants, internal cycles have to be applied to ensure sufficient nitrogen removal. Due to these internal cycles two stage activated sludge plants offer many possibilities in terms of process management which results in new process optimisation procedures as compared to conventional single-stage nutrient removal treatment plants. The proposed extension concept for the Main Treatment Plant of Vienna was validated with pilot plant investigations especially with regard to nitrogen removal where it proved to comply with the legal requirements. The operation of the treatment plant can easily be adapted to changes in temperature and sludge volume index occurring in full scale practice. Sludge retention time and aerobic volume in the second stage are controlled in order to secure sufficient nitrification capacity and to optimise nitrogen removal by means of the variation of the loading conditions for the two stages. The investigations confirmed that the specific two-stage activated sludge concept applied in Vienna is an economically advantageous alternative for large wastewater treatment plants with stringent requirements for nitrification and nutrient removal.


2019 ◽  
pp. 243-250
Author(s):  
Regimantas Dauknys

This article presents the wastewater treatment in small settlements and rural areas ofLithuania, including descriptions of capacity and loading of wastewater treatment plants(WWTPs), types of treatment facilities, and development trends of biological treatmentfacilities. In 2000 Lithuania had 597 WWTPs with capacity up to 1000 m3/d, 95% of them arethe biological treatment plants. Today the most of these WWTPs are unloaded due to thetendency to centralise wastewater treatment in rural areas of Lithuania that were in the eightand ninth decades.In small settlements and rural areas of Lithuania the aeration facilities are predominant. In theeight and ninth decades practically only the activated sludge systems were built. The situationbegan to change in the last decade of the last century: the biological filters and soil filtrationfacilities with discharge into surface waters were applied more frequently, so the building ofaeration facilities started to decrease.


2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Davood Nourmohammadi ◽  
Mir-Bager Esmaeeli ◽  
Hossein Akbarian ◽  
Mohammad Ghasemian

During the last decade, more stringent effluent requirements concerning the nutrients effluent values have been imposed by legislation and social concern. In this study, efficiency of total nitrogen removal in activated sludge and trickling filter processes (AS/TF) was investigated in Tehran North wastewater treatment plant. Biological system in this site was included, anoxic selector tank, aeration tank, final sedimentation, and trickling filter. A part of treated wastewater before chlorination was mixed with supernatant of dewatered sludge and fed to the trickling filter. Supernatant of dewatered sludge with high concentration of NH4-N was diluted by treated wastewater to provide complete nitrification in trickling filter Produced nitrate in trickling filter was arrived to the anoxic tank and converted to nitrogen gas by denitrification. According to the study result, low concentration of organic carbone and high concentration of NH4-N led to nitrification in TF, then nitrate denitrification to nitrogen gas occurred in selector area. NH4-N concentration decreased from 26.8 mg/L to 0.29 mg/L in TF, and NO3-N concentration increased from 8.8 mg/L to 27 mg/L in TF. Consequently, the total nitrogen decreased approximately to 50% in biological process. This efficiency has been observed in returned flow around 24% from final sedimentation into TF. It was concluded that, in comparison with biological nutrient removal processes, this process is very efficient and simple.


2006 ◽  
Vol 53 (12) ◽  
pp. 11-20 ◽  
Author(s):  
M.C.M. van Loosdrecht ◽  
S. Salem

Nitrogen removal in side stream processes offers a good potential for upgrading wastewater treatment plants (WWTPs) that need to meet stricter effluent standards. Removing nutrients from these internal process flows significantly reduces the N-load to the main treatment plant. These internal flows mainly result from the sludge processing and have a high temperature and a high concentration of ammonia. Therefore, the required reactor volumes as well as the required aerobic SRT are small. Generally, biological treatment processes are more economical and preferred over physical–chemical processes. Recently, several biological treatment processes have been introduced for sludge water treatment. These processes are available now on the activated sludge market (e.g. SHARON®, ANAMMOX® and BABE® processes). The technologies differ in concept and in the limitations guiding the application of these processes for upgrading WWTPs. This paper reviews and compares different biological alternatives for nitrogen removal in side streams. The limitations for selecting a technology from the available ones in the activated sludge market are noted and analysed. It is stressed that the choice for a certain process is based on more aspects than pure process engineering arguments.


2004 ◽  
Vol 50 (7) ◽  
pp. 49-52
Author(s):  
F. Laurich

Store and Treat (SAT) is a new concept for the management of ammonium-rich process waste aters at wastewater treatment plants. It combines the advantages of quantity management and separate biological treatment, whereby both operations are carried out in the same tank. Now the first full-scale application of that method was realized in Hamburg. As first experience shows the process can help to increase nitrogen removal and to reduce energy consumption.


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