The hydrolysis and reduction of mixing primary sludge and secondary sludge with thermophilic bacteria pretreatment

2021 ◽  
Author(s):  
Cheng Sun ◽  
Liang Guo ◽  
Yongkang Zheng ◽  
Dan Yu ◽  
Chunji Jin ◽  
...  
Keyword(s):  
Thermophilic Bacteria ◽  
Primary Sludge ◽  
Secondary Sludge

An innovative sludge management system based on separation of primary and secondary sludge treatment

2004 ◽  
Vol 50 (9) ◽  
pp. 145-153 ◽  
Author(s):  
G. Mininni ◽  
C.M. Braguglia ◽  
R. Ramadori ◽  
M.C. Tomei
Keyword(s):  
Energy Conversion ◽  
Management System ◽  
Sewage Treatment Plant ◽  
Treatment Plant ◽  
Nitrogen And Phosphorus ◽  
Sludge Management ◽  
Sludge Treatment ◽  
Gas Treatment ◽  
Primary Sludge ◽  
Secondary Sludge

An innovative sludge management system based on separation of treatment and disposal of primary and secondary sludge is discussed with reference to a sewage treatment plant of 500,000 equivalent person capacity. Secondary sludge, if treated separately from primary sludge, can be recovered in agriculture considering its relatively high content of nitrogen and phosphorus and negligible presence of pathogens and micropollutants. One typical outlet for primary sludge is still incineration which can be optimised by rendering the process auto thermal and significantly reducing the size of the incineration plant units (dryer, fluidised bed furnace, boiler and units for exhaust gas treatment) in comparison with those required for mixed sludge incineration. Biogas produced in anaerobic digestion is totally available for energy conversion when sludge treatment separation is performed, while in the other case a large proportion may be used as fuel in incineration, thus reducing the net electric energy conversion from 0.85-0.9 to 0.35-0.4 MW for the plant considered.

Microflore hétérotrophe impliquée dans le procédé simultané de biolixiviation des métaux et de digestion des boues d'épuration

2001 ◽  
Vol 28 (1) ◽  
pp. 158-174 ◽  
Author(s):  
M Gamache ◽  
J F Blais ◽  
R D Tyagi ◽  
N Meunier
Keyword(s):  
Sewage Sludge ◽  
Heterotrophic Bacteria ◽  
Bacterial Species ◽  
Microbial Populations ◽  
Primary Sludge ◽  
Sludge Digestion ◽  
Isolation And Characterization ◽  
Secondary Sludge ◽  
Blastoschizomyces Capitatus

Until now, some microbiological studies have made it possible to highlight the role and identification of certain chimiolithotroph microorganisms directly involved in the simultaneous sewage sludge digestion and metal leaching (SSDML process). Moreover, some other studies have established the performance of the SSDML process for the destruction of pathogens. However, until now no study has been carried out to define the equilibrium of the heterotrophic microbial populations during the sludge acidification occurring during the operation of the SSDML process. Hence, the SSDML process was studied in batch and continuous mode employing different types of sludges (Communauté Urbaine de Québec (CUQ)-East primary sludge, Beauceville secondary sludge, and mixture of primary and secondary Valcartier sludge). The equilibrium of heterotrophic microbial populations was investigated along with sludge acidification and solids degradation. The results obtained during the SSDML process on different sludges showed a decrease followed by the destruction of a majority of heterotrophic bacterial species found in fresh sludges. The isolation and characterization of different microbial species showed that only two types of microorganisms persisted: the yeast Blastoschizomyces capitatus and an unidentified fungus.Key words: sewage sludge, simultanous bioleaching and digestion, heterotrophic bacteria, Blastoschizomyces capitatus, fungi.

Nitrogen Dynamics of Pulp and Paper Sludge Amendment to Forest Soils

1991 ◽  
Vol 24 (3-4) ◽  
pp. 417-425 ◽  
Author(s):  
C. L. Henry
Keyword(s):  
Forest Soils ◽  
Soil Amendment ◽  
Growth Response ◽  
Pulp And Paper ◽  
Paper Sludge ◽  
Primary Sludge ◽  
Soil Storage ◽  
Secondary Sludge ◽  
Excellent Growth ◽  
Fate Of Nitrogen

The use of pulp and paper sludge as a forest soil amendment was investigated in these studies. The fate of nitrogen added from field applications of P&P sludge was determined. Primary sludge was found to immobilize small amounts of N, while secondary sludge mineralized over 70% of the N over a 21 month period. A large portion (39-82%) of the mineralized N was not accounted for by uptake, soil storage and nitrate leaching, and was assumed to be gaseous losses. Growth response from P&P sludge amendments was measured. Surface application of primary sludge apparently had a beneficial mulching effect, as growth was 52-131% greater than in control soils. Addition of N to primary sludge resulted in growth 151-223% greater than in controls. Secondary sludge surface-applied resulted in excellent growth compared to controls (112-319% greater).

Estimation of pharmaceutical residues in primary and secondary sewage sludge based on quantities of use and fugacity modelling

2002 ◽  
Vol 46 (3) ◽  
pp. 105-113 ◽  
Author(s):  
S.J. Khan ◽  
J.E. Ongerth
Keyword(s):  
Sewage Sludge ◽  
General Procedure ◽  
Analytical Data ◽  
Primary Sludge ◽  
Pharmaceutical Residues ◽  
Secondary Sludge

A general procedure was developed for estimating the concentrations of pharmaceutical residues in fresh primary and secondary sewage sludge. Prescribed quantities coupled with information on the various excretion ratios of 20 pharmaceuticals and 2 of their metabolites enabled prediction of the overall rates of excretion into Australian sewage. Fugacity modelling was applied to predict concentrations of these residues in fresh primary and secondary sludge. Predicted concentrations ranged from 10−3 - 884 μg/L in primary sludge and 10-4 - 36 μg/L in secondary sludge. Overall rates of removal to sludges ranged from 1-39%. The accuracy of the model was verified by comparison to analytical data.

scholarly journals Species and Bio-Availability of Inorganic and Organic Phosphorus in Primary, Secondary and Digested Sludge

2018 ◽  
Author(s):  
Shaoxiang Zhang ◽  
Wenli Huang ◽  
Dongfang Liu
Keyword(s):  
Sewage Sludge ◽  
Organic Phosphorus ◽  
Treatment Plant ◽  
Optimal Choice ◽  
Land Application ◽  
Digested Sludge ◽  
Primary Sludge ◽  
Secondary Sludge ◽  
Study Results ◽  
P Fraction

The species and bio-availability of phosphorus (P) in primary, secondary and digested sludge were fractionated and further analyzed in this study. Results showed that inorganic P (IP) was the primary P fraction in the secondary sludge and digested sludge, in which non-apatite IP (NAIP) amounted to 91.6% and 69.3% of IP, respectively. Organic P (OP), accounting for about 71.7% of total P (TP), was the dominant P composition in primary sludge. The content of bio-available P was about 9.7, 43.4, 29.8 mg-P/g-TS in primary sludge, secondary sludge and digested sludge, respectively, suggesting secondary sludge is the optimal choice when land application of sewage sludge is taken into consideration, followed by digested sludge and primary sludge. Polyphosphate and orthophosphate, comprising approximately 54.3% and 89.2% of TP, was the dominant P species in the secondary sludge and digested sludge, respectively. Monoester-P (54.6% of TP in extract) and diester- P (24.1%) were identified as OP species in primary sludge by Phosphorus-31 nuclear magnetic resonance (31PNMR). The present results would be helpful for P recovery and recycle from sewage sludge in wastewater treatment plant.

Thermal pre-treatment of primary and secondary sludge at 70 °°C prior to anaerobic digestion

2005 ◽  
Vol 52 (1-2) ◽  
pp. 161-166 ◽  
Author(s):  
I.V. Skiadas ◽  
H.N. Gavala ◽  
J. Lu ◽  
B.K. Ahring
Keyword(s):  
Organic Matter ◽  
Anaerobic Digestion ◽  
Low Cost ◽  
Methane Recovery ◽  
Primary Sludge ◽  
Thermophilic Anaerobic Digestion ◽  
Secondary Sludge ◽  
Thermophilic Digestion ◽  
Pre Treatment ◽  
Digestion Step

In general, mesophilic anaerobic digestion of sewage sludge is more widely used compared to thermophilic digestion, mainly because of the lower energy requirements and higher stability of the process. However, the thermophilic anaerobic digestion process is usually characterised by accelerated biochemical reactions and higher growth rate of microorganisms resulting in an increased methanogenic potential at lower hydraulic retention times. Furthermore, thermal pre-treatment is suitable for the improvement of stabilization and could be realized at relatively low cost especially at low temperatures. The present study investigates the effect of the pre-treatment at 70 °C on thermophilic (55 °C) anaerobic digestion of primary and secondary sludge in continuously operated digesters. Thermal pre-treatment of primary and secondary sludge at 70 °C enhanced the removal of organic matter and the methane production during the subsequent anaerobic digestion step at 55 °C. It also greatly contributed to the destruction of pathogens present in primary sludge. Finally it results in enhanced microbial activities of the subsequent anaerobic step suggesting that the same efficiencies in organic matter removal and methane recovery could be obtained at lower HRTs.

Digestion and Disposal of Primary and Secondary Sludge

2019 ◽  
pp. 255-292
Keyword(s):  
Wastewater Treatment ◽  
Sewage Sludge ◽  
Chemical Precipitation ◽  
Complex Problem ◽  
Waste Biomass ◽  
Primary Sludge ◽  
Treatment Processes ◽  
Secondary Sludge ◽  
Biological Treatments ◽  
Treatment And Disposal

Sewage sludge is the solid, semisolid, or slurry residual material that is produced as a byproduct of wastewater treatment processes. This residue is commonly classified as primary and secondary sludge. Primary sludge is generated from chemical precipitation, sedimentation, and other primary processes, whereas secondary sludge is the activated waste biomass resulting from biological treatments. Quite often the sludges are combined together for further treatment and disposal. Sludge from biological treatment operations is sometimes referred to as wastewater biosolids. Of the constituents removed by the treatment, solids and biosolids are by far the largest in volume, and their processing, reuse, and disposal present perhaps the most challenging environmental problem and complex problem in wastewater treatment processes. Therefore, the chapter is devoted to the discussion of the sources, characteristics, quantities, disposal, digestion, and stabilization of sludge so as to present background data and information on these topics that will serve as a basis for the designing of sludge processing, treatment, and disposal facilities.

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.

A comparison of ultrasound treatment on primary and secondary sludges

2004 ◽  
Vol 50 (9) ◽  
pp. 91-97 ◽  
Author(s):  
T. Mao ◽  
S.-Y. Hong ◽  
K.-Y. Show ◽  
J.-H. Tay ◽  
D.-J. Lee
Keyword(s):  
Particle Size ◽  
Treatment Method ◽  
Ultrasound Treatment ◽  
Shear Forces ◽  
Optimal Range ◽  
Primary Sludge ◽  
Remarkable Improvement ◽  
Solids Concentration ◽  
Secondary Sludge ◽  
Key Factor

Ultrasound treatment of primary and secondary sludges was conducted to improve the qualities of sludges for the anaerobic digestion. The impacts of different sonication times, sonication densities and olids concentrations on ultrasonication efficiency were examined. The experimental results indicated that the significant reduction in particle size and increase in soluble organics could be achieved, implying that ultrasonication could offer a feasible treatment method to efficiently disintegrate sludge. The greater decrease in particle size and increase in soluble organics of sludge indicated that the secondary sludge has a more remarkable improvement after sonication over the primary sludge. With respects to the extent of disintegration and energy consumption, higher sonication density performed more effectively in terms of specific energy. There exists an optimal solids concentration range for both the sludges for optimum sonication. Within the optimal solids concentration range, efficient sonication can be effected and sludge would be disintegrated efficiently. The ultrasound would be attenuated by scattering and absorption if the solids concentration exceeds the optimal range. It appeared from the study that the mechanical shear forces caused by ultrasonic cavitation could be a key factor for sludge disintegration and collapse of cavitation bubbles could significantly alter the sludge characteristics.

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