Influence of wastewater treatment on sludge production and processing

2015 ◽  
Vol 10 (1) ◽  
pp. 178-186 ◽  
Author(s):  
W. P. F. Barber
Keyword(s):  
Wastewater Treatment ◽  
Anaerobic Digestion ◽  
Thermal Energy ◽  
Energy Recovery ◽  
Energy Content ◽  
Primary Sludge ◽  
Secondary Sludge ◽  
Configuration Changes ◽  
Chemical Sludge ◽  
Sludge Production

The challenge of stricter wastewater standards is resulting in configuration changes to wastewater treatment. As facilities upgrade, the type of sludge produced is changing, with growing quantities of secondary and chemical sludge at the expense of primary sludge. It is already understood that secondary sludge is harder to treat than its primary equivalent; therefore, increasing the quantity of this type of sludge will have detrimental impacts downstream. As legislation tightens further, extended aeration times may be required during processing to remove more nutrients. Work has shown that extended aeration further exacerbates the difficulty of treating secondary sludge. This paper explains how tightening wastewater legislation fundamentally alters the nature of the sludge produced and how this affects further processing, especially with respect to sludge production and type; sludge energy content; performance of anaerobic digestion and dewatering, and potential for thermal energy recovery.

scholarly journals Modelling the bioenergy potential of municipal wastewater treatment plants

2018 ◽  
Vol 77 (11) ◽  
pp. 2613-2623 ◽  
Author(s):  
Kerstin Schopf ◽  
Johannes Judex ◽  
Bernhard Schmid ◽  
Thomas Kienberger
Keyword(s):  
Wastewater Treatment ◽  
Sewage Sludge ◽  
Energy Recovery ◽  
Municipal Wastewater ◽  
Energy Content ◽  
Treatment Plant ◽  
High Energy ◽  
Recovery Efficiency ◽  
Municipal Wastewater Treatment ◽  
Self Sufficiency

Abstract A municipal wastewater treatment plant accounts for a large portion of the total energy consumption of a municipality. Besides their high energy demand, the plants also display a significant bioenergy potential. This is due to the utilisation of the energy content of digester gas and sewage sludge if there exist suitable units. To maximise the energy recovery efficiency of wastewater treatment systems (WWTS), it is important to analyse the amount of digester gas and sludge produced in different types of plants. Therefore, the present paper deals with designing a tool to answer the following research questions: Which bioenergy potentials occur in different plant types? Which mass and energy flows are related to the specific potentials? Which utilisation processes for the potentials can lead to a high energy recovery efficiency of WWTS? Preliminary analyses with the designed tool were focused on estimating the level of electric and thermal energy self-sufficiency of different plant configuration scenarios including or excluding digester gas and/or sludge utilisation units. First results based on the level of self-sufficiency and associated energy and disposal costs show that a digester gas and sewage sludge utilisation should be considered when designing future WWTS.

Minimisation of excess sludge production in a WWTP by coupling thermal hydrolysis and rapid anaerobic digestion

2005 ◽  
Vol 52 (10-11) ◽  
pp. 255-263 ◽  
Author(s):  
J. Chauzy ◽  
S. Graja ◽  
F. Gerardin ◽  
D. Crétenot ◽  
L. Patria ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Anaerobic Digestion ◽  
Pilot Plant ◽  
Hydraulic Retention Time ◽  
Wastewater Treatment Plants ◽  
Control Line ◽  
Thermal Hydrolysis ◽  
Excess Sludge ◽  
Anaerobic Digesters ◽  
Sludge Production

In many cases, reducing sludge production could be the solution for wastewater treatment plants (WWTP) that here difficulty evacuating the residuals of wastewater treatment. The aim of this study was to test the possibility of minimising the excess sludge production by coupling a thermal hydrolysis stage and an anaerobic digestion with a very short HRT. The tests were carried out on a 2,500 p.e. pilot plant installed on a recycling loop between the clarifier and the actived sludge basin. The line equipped with the full scale pilot plant produced 38% TSS less than the control line during a 10 week period. Moreover, the rapid anaerobic digestion removed, on average, more than 50% of the total COD load with a hydraulic retention time (HRT) of 3 days. Lastly, the dryness of the remaining excess sludge, sanitised by the thermal hydrolysis, was more than 35% with an industrial centrifuge. This combination of thermal hydrolysis and rapid anaerobic digestion equally permits a significant gain of compactness compared to traditional anaerobic digesters.

The potential for thermal energy recovery from wastewater treatment works in southern England

2012 ◽  
Vol 3 (4) ◽  
pp. 287-299 ◽  
Author(s):  
Christopher Hawley ◽  
Richard Fenner
Keyword(s):  
Wastewater Treatment ◽  
Carbon Footprint ◽  
Thermal Energy ◽  
Energy Recovery ◽  
Shadow Price ◽  
Economic Feasibility ◽  
Heat Extraction ◽  
Southern England ◽  
Financial Feasibility ◽  
Discharge Temperature

This paper asks how much heat could be recovered from wastewater treatment plants under UK climatic conditions, and can this heat be used effectively to reduce their carbon footprint? Four wastewater treatment sites in southern England have been investigated and the available heat quantified. Issues relating to the environmental, economic and practical constraints on how this energy can be realistically recovered and utilised are discussed. The results show there is a definite possibility for thermal energy recovery and demonstrates that the financial feasibility of three options for using the heat (either for district heating, sludge drying or thermophilic heating in sludge digestion processes) is highly dependent upon the current shadow price of carbon. Without the inclusion of the cost of carbon, the financial feasibility is significantly limited. An environmental constraint for the allowable discharge temperature of effluent after heat extraction was found to be the major limitation to the amount of energy available for recovery. The paper establishes the true potential of thermal energy recovery from wastewater in English conditions and the economic feasibility of reducing the carbon footprint of wastewater treatment operations using this approach.

Evaluation of chemical sludge production in wastewater treatment processes

2015 ◽  
Vol 57 (35) ◽  
pp. 16346-16352 ◽  
Author(s):  
Natália Rodrigues Guimarães ◽  
Sidney Seckler Ferreira Filho ◽  
Bruno Piotto Hespanhol ◽  
Roque Passos Piveli
Keyword(s):  
Wastewater Treatment ◽  
Treatment Processes ◽  
Chemical Sludge ◽  
Sludge Production

scholarly journals ANAEROBIC DIGESTION OF SLUDGE IN WASTEWATER TREATMENT PLANT FOR ENERGY RECOVERY – A CASE STUDY OF HANOI URBAN DISTRICT

2018 ◽  
Vol 54 (2A) ◽  
pp. 21
Author(s):  
Bui Thi Thuy
Keyword(s):  
Wastewater Treatment ◽  
Anaerobic Digestion ◽  
Wastewater Treatment Plant ◽  
Energy Recovery ◽  
Biogas Production ◽  
Treatment Plant ◽  
Waste To Energy ◽  
Urban District ◽  
Additional Energy ◽  
Sludge Stabilization

In a wastewater treatment plant (WWTP) energy optimization is a big concern whilst sludge stabilization and energy recovery by anaerobic digestion implementation has recently gained importance. The calculation of an urban district level (selected as Long Bien) with 352,000 populations showed that with a total energy required of 39,750 kWh per day in WWTP, it could be supplied by utilization of biogas production, varying from 0% to ~ 43.44 % depending upon the non-application or application of anaerobic digestion for sludge treatment. In mesophylic anaerobic digestion, the biogas yields production of the calculated WWTP was obtained at 3,710 m3/day; equal to 8,394 kWh power and 13,919 kWh heat per day. As a conventional treatment process, centrifugal dewatering of sludge required an additional energy of 1,376 kWh per day for recycling, pumping, mixing as well as transporting sludge. The conclusion was that anaerobic digestion can reduce the green-house gases versus conventional dewatering. The results from this research can thus demonstrate the applicability of anaerobic digestion on conversion of waste to energy, looking forward to resource recovery.

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