Using recycled chemical sludge as a coagulant aid in chemical wastewater treatment in Mobarakeh Steel Complex

2020 ◽  
Vol 22 (3) ◽  
pp. 745-756 ◽  
Author(s):  
Masoud Taheriyoun ◽  
Alireza Memaripour ◽  
Mohammad Nazari-Sharabian
Keyword(s):  
Wastewater Treatment ◽  
Chemical Sludge

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

Traitement des eaux usées par coagulation-floculation avec recirculation des boues chimiques : Influence des réactifs

2000 ◽  
Vol 27 (4) ◽  
pp. 719-734
Author(s):  
Frédéric Monette ◽  
François G Brière ◽  
Michel Létourneau ◽  
Marc Duchesne ◽  
Robert Hausler
Keyword(s):  
Wastewater Treatment ◽  
Wastewater Treatment Plant ◽  
Treatment Plant ◽  
Pollutant Removal ◽  
Sludge Recycling ◽  
Chemical Sludge ◽  
Flocculation Process

Three series of tests were carried out at laboratory and pilot levels to examine the functions of reagents (coagulant, flocculant, sludge) involved in a coagulation-flocculation process with chemical sludge recycling. Results showed that the recycled sludge participates favourably in the process. The gains in efficiency are particularely significant for lower coagulant concentrations when flocculant concentration is not limitative. The pollutant removal increases with the sludge recycling load but seems reversible and dependent on coagulant concentration. Results also revealed the advantages of recycling sludge before injecting coagulant. To decrease the total chemical costs at a wastewater treatment plant, the strategy must focus on diminishing the coagulant concentration and increasing the flocculant concentration while maintaining a sufficient recycling sludge load to ensure gains in efficiency.Key words: recycling, sludge, preformed flocs, reagents, coagulation-flocculation, treatment, wastewater.

Traitement des eaux usées par coagulation-floculation avec recirculation des boues chimiques : Performance générale et stabilité du procédé

2000 ◽  
Vol 27 (4) ◽  
pp. 702-718
Author(s):  
Frédéric Monette ◽  
François G Brière ◽  
Michel Létourneau ◽  
Marc Duchesne ◽  
Robert Hausler
Keyword(s):  
Wastewater Treatment ◽  
Wastewater Treatment Plant ◽  
Treatment Plant ◽  
Normal Plant ◽  
Plant Operation ◽  
Load Variations ◽  
Sludge Recycling ◽  
The Stability ◽  
Chemical Sludge ◽  
Flocculation Process

Six series of tests were carried out to have a better understanding of the stability and efficiency of a coagulation-flocculation process with chemical sludge recycling. The tests consisted in sequential sludge recycling in 100-L pilot reactors. Other tests were performed to examine the stability following wastewater loading variations. Results showed that stability was reached immediately during the first recycling sequences. Furthermore, to obtain improved results compared with those of a classical coagulation-flocculation process, the flocculant concentration must be increased according to the sludge recycling load. Results also revealed that recycling sludge does not absorb wastewater load variations. Consequently, the implementation of sludge recycling in a wastewater treatment plant would not cause effluent degradation or entail major changes in a normal plant operation routine. The predominant coagulation-flocculation mechanisms that explained the increase in efficiency, in comparison with the classical process, were identified as enmeshment and sweep flocculation. Finally, the recycled sludge produced were conditioned and dewatered in a fashion similar to that of a classical process.Key words: recycling, sludge, preformed flocs, coagulation-flocculation, treatment, wastewater, stability.

Traitement des eaux usées par coagulation-floculation avec recirculation des boues chimiques : Évaluation et validation à grande échelle

2000 ◽  
Vol 27 (4) ◽  
pp. 735-753
Author(s):  
Frédéric Monette ◽  
François G Brière ◽  
Michel Létourneau ◽  
Marc Duchesne ◽  
Robert Hausler
Keyword(s):  
Wastewater Treatment ◽  
Treatment Plant ◽  
Water Tank ◽  
Small Particles ◽  
Recycling Process ◽  
Sludge Recycling ◽  
Work Done ◽  
Chemical Sludge ◽  
Flocculation Process

Two sequences of tests were carried out at the Centre d'épuration Rive-Sud wastewater treatment plant (Longueuil, Que.) to evaluate the performances of a coagulation-flocculation process with chemical sludge recycling. The tests consisted in following the evolution of the quality of the treated water when two flowsheets are supplied simultaneously in parallel with the same wastewater, one flowsheet incorporating the sludge recycling process. Results showed that the recycled sludge contributes significantly to water degradation compared with a classical coagulation-flocculation system. These results do not corroborate the previous work done by Monette et al. (F. Monette et al. Canadian Journal of Civil Engineering, 27: 702-718, 719-734, 2000). The problems observed are explained by inadequate plant installations for sludge recycling. High coagulant concentrations also limit the gains in efficiency associated with recyling. The process reacts rapidly to wastewater loading and reagent modifications. The recycled sludge conditioning is slightly more difficult because of the small particles created by recycling pump turbulence. Finally, turbidity measurements in the flocculator water tank could be used as an excellent indicator for sludge recycling load estimation.Key words: recycling, sludge, coagulation-flocculation, treatment, wastewater, full scale.

Wastewater Sludge Dewatering for Champion-Hamilton Treatment Facility

1999 ◽  
Vol 40 (11-12) ◽  
pp. 155-162
Author(s):  
Roscoe F. Ward ◽  
Billy Huston
Keyword(s):  
Wastewater Treatment ◽  
Treatment Plant ◽  
Wastewater Sludge ◽  
Sludge Dewatering ◽  
Paper Mills ◽  
Sludge Disposal ◽  
Sludge Cake ◽  
Motor Load ◽  
Chemical Sludge ◽  
Made In

Paper mills are under constant pressure to increase their profits and to reduce their wastewater treatment costs. Champion International Mill in Hamilton, Ohio, is not an exception. The mill produces 340 to 365 tons/day of coated and uncoated printing and writing papers. Prior to 1996, Champion used less than 60 tons/day of secondary fiber. The usage of secondary fiber has increased to 100 to 114 tons/day. In 1996 improvements were made in the mill to reduce fiber losses. At that time the corporation also changed suppliers of polymers. As a result of these changes, the wastewater treatment plant saw its sludge disposal costs increasing. The solids from their screw presses decreased from 55% to 48%. This paper reports the series of options that were examined to improve the dewatering and to lower disposal costs. Included are changes in polymers and polymer applications, changes in the chemical sludge mixing, improved press orifice cleaning, and screw press motor load control systems. The effects of these changes have resulted in improved dewatering and the potential for even higher solids in the sludge cake. The economics of the sludge dewatering system are reviewed.

Dewatering of Drying Beds–Combined Biological-Chemical Sludge Behaviour

1993 ◽  
Vol 28 (10) ◽  
pp. 65-72 ◽  
Author(s):  
S. Marklund
Keyword(s):  
Wastewater Treatment ◽  
Wastewater Treatment Plant ◽  
Treatment Plant ◽  
Drying Rate ◽  
Controlled Environment ◽  
Air Humidity ◽  
Digested Sludge ◽  
Drying Time ◽  
Total Solids ◽  
Chemical Sludge

Aerobically digested sludge from a small wastewater treatment plant was dewatered on five sand drying pilot beds and four small drainage beds. The experiment was conducted in a controlled environment with constant air humidity and temperature. A total of between 147 and 263 kg of a combined biological-chemical sludge was used on each of the sand drying beds. Initial sludge total solids (TS) content was 4.6 - 5.5%. Sludge drainage was completed within 28 days, and the thinner sludge layers were drained within 16 days. The sludge evaporation phase, prior to equilibrium with air moisture, lasted a maximum of 84 days and resulted in a final TS content of 88 - 92%. The drying time to achieve 30% TS was 35-50 days, depending on initial sludge thickness. Sludge cracking behaviour or rate did not control the drying rate at less than 30% TS.

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.

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