scholarly journals Removal and transformation of pharmaceuticals in wastewater treatment plants and constructed wetlands

2013 ◽  
Vol 6 (1) ◽  
pp. 97-117 ◽  
Author(s):  
E. Lee ◽  
S. Lee ◽  
J. Park ◽  
Y. Kim ◽  
J. Cho
Keyword(s):  
Wastewater Treatment ◽  
Constructed Wetlands ◽  
Surface Waters ◽  
Biological Treatment ◽  
Wastewater Treatment Plants ◽  
Wastewater Effluent ◽  
Trace Organic Compounds ◽  
Initial Transformation ◽  
The Stability ◽  
D Value

Abstract. Since trace organic compounds such as pharmaceuticals in surface water have been a relevant threat to drinking water supplies, in this study the removal of pharmaceuticals and transformation of pharmaceuticals into metabolites were investigated in the main sources of micropollutants such as wastewater treatment plants (WWTPs) and engineered constructed wetlands. Pharmaceuticals were effectively removed by different WWTP processes and wetlands. Pharmaceutical metabolites with relatively low log D value resulted in the low removal efficiencies compared to parent compounds with relatively high log D value, indicating the stability of metabolites. And the constructed wetlands fed with wastewater effluent were encouraged to prevent direct release of micropollutants into surface waters. Among various pharmaceuticals, different transformation pattern of ibuprofen was observed with significant formation of 1-hydroxy-ibuprofen during biological treatment in WWTP, indicating preferential biotransformation of ibuprofen. Lastly, transformation of pharmaceuticals depending on their structural position was investigated in terms of electron density, and the electron rich C1 = C2 bond of carbamazepine was revealed as an initial transformation position.

scholarly journals Removal and transformation of pharmaceuticals in wastewater treatment plants and constructed wetlands

2013 ◽  
Vol 6 (2) ◽  
pp. 89-98 ◽  
Author(s):  
E. Lee ◽  
S. Lee ◽  
J. Park ◽  
Y. Kim ◽  
J. Cho
Keyword(s):  
Constructed Wetlands ◽  
Surface Waters ◽  
Biological Treatment ◽  
Wastewater Treatment Plants ◽  
Wastewater Effluent ◽  
Trace Organic Compounds ◽  
Initial Transformation ◽  
The Stability ◽  
Trace Organic ◽  
D Value

Abstract. Since trace organic compounds such as pharmaceuticals in surface water have been a relevant threat to drinking water supplies, in this study removal of pharmaceuticals and transformation of pharmaceuticals into metabolites were investigated in the main source of micropollutants such as WWTPs and engineered constructed wetlands. Pharmaceuticals were effectively removed by different WWTP processes and wetlands. Pharmaceutical metabolites with relatively low log D value were resulted in the low removal efficiencies compared to parent compounds with relatively high log D value, indicating the stability of metabolites. And the constructed wetlands fed with wastewater effluent were encouraged to prevent direct release of micropollutants into surface waters. Among various pharmaceuticals, different transformation pattern of ibuprofen was observed with significant formation of 1-hydroxy-ibuprofen during biological treatment in WWTP, indicating preferential biotransformation of ibuprofen. Lastly, transformation of pharmaceuticals depending on their structural position was investigated in terms of electron density, and, the electron rich C1 = C2 bond of carbamazepine was revealed as an initial transformation position.

Evaluation of Small Wastewater Treatment Plants in the County of Århus – Denmark

1993 ◽  
Vol 28 (10) ◽  
pp. 33-41
Author(s):  
Jes la Cour Jansen ◽  
Bodil Mose Pedersen ◽  
Erik Moldt
Keyword(s):  
Wastewater Treatment ◽  
Constructed Wetlands ◽  
Biological Treatment ◽  
Wastewater Treatment Plants ◽  
Chemical Precipitation ◽  
Common Type ◽  
Treatment Efficiency ◽  
Effluent Quality ◽  
Different Types

Influent and effluent data from about 120 small wastewater treatment plants (100 - 2000 PE) have been collected and processed. Seven different types of plants are represented. The effluent quality and the treatment efficiency have been evaluated. The most common type of plant is mechanical/biological treatment plants. Some of them are nitrifying and some are also extended for chemical precipitation of phosphorus. Constructed wetlands and biological sandfilters are also represented among the small wastewater treatment plants.

scholarly journals The present situation and trends of wastewater treatment in small settlements and rural areas of Lithuania

2019 ◽  
pp. 243-250
Author(s):  
Regimantas Dauknys
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Surface Waters ◽  
Rural Areas ◽  
Biological Treatment ◽  
Wastewater Treatment Plants ◽  
Present Situation ◽  
Treatment Facilities ◽  
Biological Filters ◽  
Activated Sludge Systems

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.

Ammonia removal in a pilot-scale WSP complex in Northeast Brazil

1996 ◽  
Vol 33 (7) ◽  
pp. 165-171 ◽  
Author(s):  
J. Soares ◽  
S. A. Silva ◽  
R. de Oliveira ◽  
A. L. C. Araujo ◽  
D. D. Mara ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Surface Waters ◽  
Wastewater Treatment Plants ◽  
Pilot Scale ◽  
Ammonia Removal ◽  
Northeast Brazil ◽  
Environmental Legislation ◽  
Aerobic Conditions ◽  
High Degree

Ammonia removal was monitored in a waste stabilisation pond complex comprising ponds of different geometries and depths under two different operational regimes. It was found that a high degree of ammonia removal commenced in the secondary maturation ponds, with the highest removals occurring in the shallowest ponds as a consequence of improved aerobic conditions. The tertiary maturation ponds produced effluents with mean ammonia concentrations of < 5 mg N/l, the maximum permitted recommended by Brazilian environmental legislation for the discharge of effluents of wastewater treatment plants into surface waters. Ammonia removal in the secondary facultative and maturation ponds could be modelled using equations based on the volatilization mechanism proposed by Middlebrooks et al. (1982).

Research on Variable Metric Chaos Optimization Modeling for the Prediction of Wastewater Treatment Plants Performance

2012 ◽  
Vol 428 ◽  
pp. 169-175
Author(s):  
Guo Kai Fu ◽  
Yi Yue Hu ◽  
Zhi Zhang
Keyword(s):  
Neural Network ◽  
Wastewater Treatment ◽  
Wastewater Treatment Plant ◽  
Wastewater Treatment Plants ◽  
Treatment Plant ◽  
Treatment System ◽  
Variable Metric ◽  
Chaos Optimization ◽  
Actual Operation ◽  
The Stability

A reliable model for any wastewater treatment plant is essential in order to provide a tool for predicting its performance and to form a basis for controlling the operation of the process. This would minimize the operation costs and assess the stability of environmental balance. For the multi-variable, uncertainty, non-linear characteristics of the wastewater treatment system, a variable metric chaos optimization neural network (VMCNW) prediction model is established standing on the actual operation data in the wasterwater treatment system. The model overcomes several disadvantages of the conventional BP neural network. Namely:slow convergence, low accuracy and difficulty in finding the global optimum.The results of model calculation show that the predicted value can better match measured value,played a effect of simulating and predicting and be able to optimize the operation status. The establishment of the predicting model provide a simple and practical way for the operation and management in wastewater treatment plant,and have good research and engineering practical value.

scholarly journals Global Internal Recirculation Alternative Operation to Reduce Nitrogen and Ammonia Limit Violations and Pumping Energy Costs in Wastewater Treatment Plants

Processes ◽  
2020 ◽  
Vol 8 (12) ◽  
pp. 1606
Author(s):  
Ignacio Santín ◽  
Ramon Vilanova ◽  
Carles Pedret ◽  
Marian Barbu
Keyword(s):  
Wastewater Treatment ◽  
Flow Rate ◽  
Biological Treatment ◽  
Fuzzy Controller ◽  
Wastewater Treatment Plants ◽  
Nitrate Concentration ◽  
Great Influence ◽  
Energy Costs ◽  
Recirculation Flow ◽  
Operational Costs

The internal recirculation plays an important role in different areas of the biological treatment of wastewater treatment plants because it has a great influence on the concentration of pollutants, especially nutrients. A usual manipulation of the internal recirculation flow rate is based on the target of controlling the nitrate concentration in the last anoxic tank. This work proposes an alternative for the manipulation of the internal recirculation flow rate instead of nitrate control, with the objective of avoiding limit violations of nitrogen and ammonia concentrations and reducing operational costs. A fuzzy controller is proposed to achieve it based on the effects of the internal recirculation flow rate in different areas of the biological treatment. The proposed manipulation of the internal recirculation flow rate is compared to the application of the usual nitrate control in an already established and published operation strategy by using the internationally known benchmark simulation model no. 2 as a working scenario. The results show improvements with reductions of 59.40% in ammonia limit violations, 2.35% in total nitrogen limit violations, and 38% in pumping energy costs.

Performance of activated sludge diffusion for biological treatment of hydrogen sulphide gas emissions

2013 ◽  
Vol 68 (9) ◽  
pp. 1932-1939 ◽  
Author(s):  
Vera L. Barbosa ◽  
Richard M. Stuetz
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Hydrogen Sulphide ◽  
Biological Treatment ◽  
Suspended Solids ◽  
Wastewater Treatment Plants ◽  
Broad Application ◽  
H2s Removal ◽  
Treatment Performance ◽  
Solids Concentration

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.

Design Recommendations for Subsurface Flow Constructed Wetlands for Nitrification and Denitrification

1999 ◽  
Vol 40 (3) ◽  
pp. 257-263 ◽  
Author(s):  
Christoph Platzer
Keyword(s):  
Wastewater Treatment ◽  
Constructed Wetlands ◽  
Wastewater Treatment Plants ◽  
Subsurface Flow ◽  
Oxygen Demand ◽  
Oxygen Balance ◽  
Vertical Flow ◽  
Soil Aeration ◽  
Return Rates ◽  
Nitrification And Denitrification

The paper presents a design for nitrogen removal in subsurface flow wetlands. The nitrification in the vertical-flow beds (VFBs) is clearly determined by the oxygen balance in the filter. Full nitrification can only be achieved when the oxygen balance is positive. For sizing purposes equations for the calculation of oxygen demand and oxygen input are given. Three possibilities to achieve sufficient soil aeration are presented and explained. For the denitrification two possibilities are presented. From technical wastewater treatment plants predenitrification is well known. Return rates up to 200% can be used without hydraulic problems for the VFBs. In cases of low C/N ratios an additional application of HFBs has to be used. The design can be carried out using a design of 1 g NO3-N/m2,d achieving a 65% removal in more than 90% of the cases. The paper discusses some of the equations presented internationally. The suitability of the use of k-values for the processes nitrification and denitrification is especially questioned.

Investigation of a Full-Scale Anaerobic-Aerobic and Constructed Wetlands Integrated System Treating Livestock Wastewater

2010 ◽  
Vol 113-116 ◽  
pp. 1189-1194
Author(s):  
Yong Ming Wu ◽  
Jin Bao Wan ◽  
Ji Hai Xiong ◽  
Shun Fa Wang ◽  
Ping Gu
Keyword(s):  
Constructed Wetlands ◽  
Biological Treatment ◽  
Large Scale ◽  
Wastewater Treatment Plants ◽  
Removal Rate ◽  
Full Scale ◽  
Integrated System ◽  
Tertiary Treatment ◽  
Livestock Wastewater ◽  
Aerobic Process

A full-scale integrated system of the IOC-SBBR and CWs for the biological treatment of livestock wastewater was carried out in this study, the combined IOC-SBBR process had the removal rates of COD, NH4+-N, TN reached 96.5%, 89% and 81.1%, respectively. CWs were used for the further tertiary treatment of livestock wastewater, which the average removal rate of the NH4+-N and TN was 61.3% and 60.2%, the overall integrated system was superior to the direct anaerobic or aerobic process for the treatment of large-scale livestock wastewater, would provide the valuable design and operation for the livestock wastewater treatment plants.

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