scholarly journals MATHEMATICAL MODELLING OF THE REMOVAL OF ORGANIC MICROPOLLUTANTS IN THE ACTIVATED SLUDGE PROCESS: A LINEAR BIODEGRADATION MODEL

2018 ◽  
Vol 60 (2) ◽  
pp. 191-229
Author(s):  
MARK I. NELSON ◽  
RUBAYYI T. ALQAHTANI ◽  
FAISAL I. HAI
Keyword(s):  
Residence Time ◽  
Wastewater Treatment Plants ◽  
Activated Sludge Process ◽  
Simple Condition ◽  
Removal Mechanism ◽  
Organic Micropollutants ◽  
Adsorption Model ◽  
Micropollutant Removal ◽  
Effluent Stream ◽  
Steady State Solutions

Before wastewaters can be released into the environment, they must be treated to reduce the concentration of organic pollutants in the effluent stream. There is a growing concern as to whether wastewater treatment plants are able to effectively reduce the concentration of micropollutants that are also contained in their influent streams. We investigate the removal of micropollutants in treatment plants by analysing a model that includes biodegradation and sorption as the main mechanisms of micropollutant removal. For the latter a linear adsorption model is used in which adsorption only occurs onto particulates.The steady-state solutions of the model are found and their stability is determined as a function of the residence time. In the limit of infinite residence time, we show that the removal of biodegradable micropollutants is independent of the processes of adsorption and desorption. The limiting concentration can be decreased by increasing the concentration of growth-related macropollutants. Although, in principle, it is possible that the concentration of micropollutants is minimized at a finite value of the residence time, this was found not to be the case for the particular biodegradable micropollutants considered.For nonbiodegradable pollutants, we show that their removal is always optimized at a finite value of the residence time. For finite values of the residence time, we obtain a simple condition which identifies whether biodegradation is more or less efficient than adsorption as a removal mechanism. Surprisingly, we find that, for the micropollutants considered, adsorption is always more important than biodegradation, even when the micropollutant is classified as being highly biodegradable with low adsorption.

scholarly journals Advanced Wastewater Treatment to Eliminate Organic Micropollutants in Wastewater Treatment Plants in Combination with Energy-Efficient Electrolysis at WWTP Mainz

Energies ◽  
2020 ◽  
Vol 13 (14) ◽  
pp. 3599 ◽  
Author(s):  
Oliver Gretzschel ◽  
Michael Schäfer ◽  
Heidrun Steinmetz ◽  
Erich Pick ◽  
Kim Kanitz ◽  
...  
Keyword(s):  
Water Management ◽  
Wastewater Treatment ◽  
Municipal Wastewater ◽  
Wastewater Treatment Plants ◽  
Biogas Production ◽  
Automatic Frequency ◽  
Municipal Wastewater Treatment ◽  
Organic Micropollutants ◽  
Micropollutant Removal

To achieve the Paris climate protection goals there is an urgent need for action in the energy sector. Innovative concepts in the fields of short-term flexibility, long-term energy storage and energy conversion are required to defossilize all sectors by 2040. Water management is already involved in this field with biogas production and power generation and partly with using flexibility options. However, further steps are possible. Additionally, from a water management perspective, the elimination of organic micropollutants (OMP) is increasingly important. In this feasibility study a concept is presented, reacting to energy surplus and deficits from the energy grid and thus providing the needed long-term storage in combination with the elimination of OMP in municipal wastewater treatment plants (WWTPs). The concept is based on the operation of an electrolyzer, driven by local power production on the plant (photovoltaic (PV), combined heat and power plant (CHP)-units) as well as renewable energy from the grid (to offer system service: automatic frequency restoration reserve (aFRR)), to produce hydrogen and oxygen. Hydrogen is fed into the local gas grid and oxygen used for micropollutant removal via upgrading it to ozone. The feasibility of such a concept was examined for the WWTP in Mainz (Germany). It has been shown that despite partially unfavorable boundary conditions concerning renewable surplus energy in the grid, implementing electrolysis operated with regenerative energy in combination with micropollutant removal using ozonation and activated carbon filter is a reasonable and sustainable option for both, the climate and water protection.

Controlling Activated Sludge Process Using EFOR

1992 ◽  
Vol 26 (3-4) ◽  
pp. 783-790
Author(s):  
J. Pedersen
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Wastewater Treatment Plants ◽  
Treatment Plant ◽  
Simulation Program ◽  
Activated Sludge Process ◽  
Activated Sludge Model

A newly developed simulation program, based on the Activated Sludge Model No. 1, has been investigated for its controlling abilities. The program is capable of simulating most of the control types which have been applied to wastewater treatment plants. The program was tested on a nitrifying and a denitrifying treatment plant. The results showed that the model makes good simulations of the applied controls.

scholarly journals Rethinking micropollutant removal assessment methods for wastewater treatment plants – how to get more robust data?

2017 ◽  
Vol 75 (12) ◽  
pp. 2964-2972 ◽  
Author(s):  
Jean-Marc Choubert ◽  
Samuel Martin Ruel ◽  
Cécile Miege ◽  
Marina Coquery
Keyword(s):  
Wastewater Treatment ◽  
Removal Efficiency ◽  
Suspended Solids ◽  
Wastewater Treatment Plants ◽  
Sampling Strategy ◽  
Sampling Uncertainty ◽  
Limit Of Quantification ◽  
Sources Of Uncertainty ◽  
Micropollutant Removal ◽  
The Impact

This paper covers the pitfalls, recommendations and a new methodology for assessing micropollutant removal efficiencies in wastewater treatment plants. The proposed calculation rules take into account the limit of quantification and the analytical and sampling uncertainty of measured concentrations. We identified six cases for which a removal efficiency value is reliable and four other cases where result is highly variable (uncertain) due to very low or unquantified concentrations in effluent or when the influent–effluent concentrations differential is below the measurement uncertainty. The influence of the proposed calculation rules on removal efficiency values was scrutinized using actual results from a research project. The paper arrives at detailed recommendations for limiting the impact of other sources of uncertainty during sampling (sampling strategy, cleaning and field blank), chemical analyses (suspended solids and sludge) and data processing according to the targeted objectives.

Fate of tetracycline resistant bacteria as a function of activated sludge process organic loading and growth rate

2007 ◽  
Vol 55 (1-2) ◽  
pp. 291-297 ◽  
Author(s):  
S. Kim ◽  
J.N. Jensen ◽  
D.S. Aga ◽  
A.S. Weber
Keyword(s):  
Growth Rate ◽  
Activated Sludge ◽  
Wastewater Treatment Plants ◽  
Tetracycline Resistance ◽  
Organic Loading Rate ◽  
Resistant Bacteria ◽  
Activated Sludge Process ◽  
Organic Loading ◽  
Specific Growth Rates ◽  
Evaluation Parameters

The objective of this research was to elucidate the fate of tetracycline resistant bacteria as a function of activated sludge organic loading rate and growth rate. Techniques employed to evaluate the effect of these factors on the fate of tetracycline resistant bacteria were: (1) resistant bacteria concentrations in the SBR biomass; (2) production of tetracycline resistant bacteria as measured by a combination of effluent efflux and intentional solids wasting; (3) net specific growth rates as determined by an SBR population balance; and (4) percentage of resistance as determined by normalising resistant concentrations to total concentrations. Based on these evaluation parameters, increases in organic loading and growth rate both resulted in amplification of tetracycline resistance. These trends were observed for activated sludge reactors loaded with typical municipal background tetracycline concentrations (∼1 μg/L) and those receiving influent augmented with 250 μg/L tetracycline. Accordingly, biological wastewater treatment plants, such as the activated sludge process, may be significant sources of antibiotic resistance to the environment.

Characteristics and evaluation of natural attenuation processes for organic micropollutant removal during riverbank filtration

2007 ◽  
Vol 7 (3) ◽  
pp. 1-7 ◽  
Author(s):  
C.K. Schmidt ◽  
F.T. Lange ◽  
H.-J. Brauch
Keyword(s):  
Urban Areas ◽  
Wide Spectrum ◽  
Riverbank Filtration ◽  
Organic Micropollutants ◽  
Micropollutant Removal ◽  
Trace Compounds ◽  
High Level ◽  
Underground Passage ◽  
Organic Trace Compounds

In industrialized and urban areas, surface waters are to a high level exposed to anthropogenic environmental impacts and are therefore often contaminated with a wide spectrum of organic trace compounds. Riverbank filtration is a well established technique in Europe and is most often used as an important component of the multiple-barrier system. During its underground passage, surface water undergoes a diversity of physical, biological and chemical processes, improving water quality significantly and adjusting it in ideal cases to the quality of natural groundwater. By means of examples taken from recent research projects and related to organic micropollutants currently under discussion, this contribution will report on characteristics of riverbank filtration with regard to its purification capacity for different classes of organic micropollutants.

Micropollutant removal by attached and suspended growth in a hybrid biofilm-activated sludge process

2013 ◽  
Vol 47 (13) ◽  
pp. 4498-4506 ◽  
Author(s):  
P. Falås ◽  
P. Longrée ◽  
J. la Cour Jansen ◽  
H. Siegrist ◽  
J. Hollender ◽  
...  
Keyword(s):  
Activated Sludge ◽  
Activated Sludge Process ◽  
Micropollutant Removal ◽  
Suspended Growth

scholarly journals POTENSI SELULASE DAN PENGARUH LAJU PEMBEBANAN PADA EFEKTIVITAS PENGOLAHAN AIR LIMBAH KERTAS PROSES LUMPUR AKTIF (POTENTIAL OF CELLULASE AND EFFECT OF LOADING RATE ON TREATMENT OF PAPER WASTEWATER OF ACTIVATED SLUDGE PROCESS)

2016 ◽  
Vol 6 (02) ◽  
Author(s):  
Andri Taufick Rizaluddin ◽  
Sri Purwati
Keyword(s):  
Activated Sludge ◽  
Residence Time ◽  
Industrial Wastewater ◽  
Organic Pollutant ◽  
Continuous Process ◽  
Oxygen Demand ◽  
Activated Sludge Process ◽  
Effluent Quality ◽  
Paper Wastewater ◽  
Enzyme Dosage

As the effluent quality standards for industrial wastewater are becoming more stringent, it is important for the industry to improve their wastewater treatment efficiency. The research about potential of cellulase application in the activated sludge process has been done. Theoritically, the addition of cellulase was required to support the activity of microorganism on the activated sludge. Since cellulose is the major organic pollutant component in the wastewater, it was expected that cellulase addition could improve the performance of activated sludge process. The experiments were conducted in a continuous process and consisted of two treatments which were with and without activated sludge at about 2400 mg MLVSS/L. The variations in each treatment were the enzyme dosages of 0; 0.2; 0.5; and 0.7 unit/g COD, and the residence time of 4, 8, 12, and 24 hours. The experiment result showed that the addition of cellulase can increase COD and BOD reduction compared to the treatment without enzymes. The highest COD reduction increment was 7.9% at the enzyme dosage of 0.2 unit/g COD and the residence time of 4 hours, while the highest BOD reduction increment was 14.6% at the same enzyme dosage and residence time. In conclusion, celullase application can be combined with the activated sludge process which will be effective in the high load organic wastewater. ABSTRAKDengan semakin ketatnya baku mutu air limbah, peningkatan efisiensi dalam pengolahan limbah menjadi sangat penting bagi industri. Penelitian ini dilakukan untuk mengetahui potensi selulase dan pengaruh laju pembebanan pada efektifitas pengolahan air limbah kertas sistem lumpur aktif. Secara teori, penambahan selulase diperlukan untuk membantu aktivitas mikroorganisme lumpur aktif. Dengan adanya kandungan selulosa sebagai komponen utama pencemar organik dalam air limbah, penambahan selulase diharapkan dapat meningkatkan kinerja proses lumpur aktif. Percobaan dilakukan dengan proses kontinyu yang terdiri dari dua perlakuan, yaitu tanpa dan dengan lumpur aktif pada MLVSS sekitar 2400 mg/L. Variasi pada setiap perlakuan berupa variasi dosis selulase (0; 0,2; 0,5; dan 0,7 unit/g COD) dan variasi laju pembebanan dengan mengatur waktu tinggal 4, 8, 12, dan 24 jam. Hasil percobaan menunjukkan bahwa perlakuan lumpur aktif dengan penambahan selulase dapat menghasilkan peningkatan reduksi COD dan BOD bila dibandingkan perlakuan tanpa menggunakan selulase. Peningkatan reduksi COD tertinggi mencapai 7,9% dengan perlakuan selulase dosis 0,2 unit/g COD dan waktu tinggal 4 jam, sedangkan peningkatan reduksi BOD tertinggi mencapai 14,6%. Perlakuan selulase dapat dikombinasikan dengan proses lumpur aktif yang berjalan efektif pada waktu tinggal yang lebih singkat atau pada beban tinggi.Kata kunci: selulase, lumpur aktif, chemical oxygen demand, biological oxygen demand

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