After the application of sludge enhancers on municipal sludge, the flocculation effect is remarkable. The specific manifestations and impacts are as follows:
I. Manifestation of Flocculation Effect
The flocs are of uniform size
Sludge enhancers aggregate sludge particles through bridging, forming relatively uniform flocs to prevent the residue of fine particles and enhance dewatering efficiency.
The floc structure is compact
Sludge enhancers disrupt the colloidal structure of sludge, reduce viscosity, promote the formation of circular and compact flocs, decrease water entrapment, and accelerate solid-liquid separation.
The flocs are concentrated in distribution
Flocs are concentrated in the sludge, forming larger flocs, which facilitate the treatment by dewatering equipment (such as filter presses and centrifuges) and enhance the dewatering efficiency.
Ii. The Mechanism of Action of Sludge Enhancers
Destroy the colloid structure
Decompose the colloidal particles in the sludge, release the bound water, reduce water entrapment and improve the dewatering performance.
Reduce the viscosity of sludge
Reduce the adhesion of sludge to equipment, enhance fluidity, lower the risk of equipment blockage, and decrease maintenance costs.
Promote the formation of flocs
Through charge neutralization and bridging, large and compact flocs are formed, accelerating sludge sedimentation and dewatering.
Improve the properties of sludge
Increase the particle size of bacterial flocs, improve the settling performance of sludge, and shorten the dewatering time.
Iii. Compatibility of Municipal Sludge Characteristics with Enhancers
High moisture content (>99%)
Municipal sludge has an extremely high moisture content and is difficult to dewater. Sludge enhancers significantly reduce the moisture content by disrupting the colloid structure, making sludge easier to dewater.
High content of organic matter
The sludge contains unstable organic compounds, which are prone to decompose and produce harmful substances. Sludge enhancers can accelerate the degradation of organic matter and reduce secondary pollution.
Colloid properties
The sludge particles are fine, with a large specific surface area and poor dewatering performance. Sludge enhancers form large flocs through bridging, improve colloidal properties and enhance dewatering efficiency.
Contain harmful substances
The sludge contains pathogenic microorganisms, heavy metals, etc. Sludge enhancers can simplify the treatment process, reduce the residue of harmful substances and lower environmental risks.
Iv. The Influence of Flocculation Effect on Dewatering Treatment
Improve dehydration efficiency
The excellent flocculation effect makes sludge easier to dewater, shortening the dewatering time by 30% to 50%, and the moisture content can be reduced to below 60%.
Reduce processing costs
Shorten the dehydration time and reduce energy consumption; Reduce equipment blockage and lower maintenance costs; Simplify the pretreatment steps and save the cost of chemicals.
Improve the properties of the mud cake
The moisture content of the mud cake is reduced, the volume is decreased, and it is convenient for transportation and disposal. The viscosity of the mud cake is improved, reducing the risk of secondary pollution.
V. Practical Application Cases
A case of deep dewatering of municipal sewage
Save 30% of processing costs.
The viscosity of the mud biscuits has increased, and the production volume has also risen.
Completely solve the problem of scaling on filter plates and pipes.
The original plan used polyacrylamide (PAM) and polyaluminium chloride (PAC), which made the conditioning process complex. The proportion of conditioning agents in the mud cake was large, and the metal content in the filtrate was high.
Solution: Use sludge enhancers to replace PAC and traditional flocculants.
Conclusion
After the application of sludge enhancers in municipal sludge, the flocculation effect was significantly improved, with uniform floc size, compact structure and concentrated distribution. Sludge enhancers improve the dewatering efficiency of sludge, lower the moisture content and reduce treatment costs through mechanisms such as destroying the colloid structure, reducing viscosity and promoting the formation of flocs. Practical application cases have proved the effectiveness and economy of sludge enhancers in municipal sludge treatment, providing efficient and economical sludge treatment solutions for sewage treatment plants.