What are the different methods of sludge digestion in STPs?
A biological process called sludge digestion converts the particles in the sludge, into stable compounds. In addition to eliminating the pathogens, the process decreases the mass of the solids and dewaters the sludge.
Let’s understand the different methods of sludge digestion in STPs!
1: Dewatering
To reduce waste, sludge is dewatered to separate it into liquids and solids. Sludge dewatering methods include centrifuging, screw pressing, geomembranes, plate & frame and belt filter presses, among others.
It is vital to remember that dewatering just separates the solid and liquid components, to make handling the different phases for eventual disposal simpler and more affordable. Dewatering is not meant to remediate the sludge or liquid. Both the solid and liquid parts of the sludge may include contaminants, which need to be handled individually after it has been dewatered.
Why is sludge dewatering necessary?
Sludge dewatering is primarily done to reduce waste and increase overall disposal cost effectiveness. Stabilized sludge also lessens health risks and allows for safer handling. Certain sludges can really be applied to the land and have a very positive utilization. Generally speaking, both the public and private sectors must dispose of sludge in a way, that is permitted by regulatory bodies, complies with their own organizational needs, and is safe for the environment.
In order to keep disposal costs, including transportation, to a minimum, sludge dewatering normally focuses on lowering the weight and volume of the sludge. Before sludge waste can be handled or disposed of in the most cost-effective manner, water removal is the main method of volume reduction.
2: Composting
It is possible to declare that composting is one of the greatest techniques to handle sludge, because it is an excellent aerobic digestion process. Sewage sludge can be combined with other wastes like wood chips, straw, or green wastes, to form a pasteurized product before it is composted.
About 20–30% of the volatile solids can be converted to carbon dioxide during composting. Composting is a low-energy process that combines natural mesophilic and thermophilic aerobic decomposition, in a largely static system that is aerated by natural diffusion.
3: Anaerobic Digestion
One of the most popular methods for stabilizing wastewater treatment plant sludge is anaerobic digestion. Anaerobic digestion is a crucial phase in the sludge treatment process before drying and burning, because it can lower the amount of organic matter by up to 50%, enhancing the post-treatment procedure and reducing expenses. Also, the methane-rich biogas that is produced can be used as a source of energy.
Advantages of anaerobic digestion
1. Production of CH4 as an extra energy source.
2. Reducing organic debris and enhancing subsequent treatments.
3. The leftover sludge can be applied to the soil to improve it.
4. Decreases the emission of greenhouse gas methane from landfills.
4: Drying-incineration
Complete combustion, or incineration, is the quick exothermic oxidation of combustible substances in sludge. In the presence of oxygen, dewatered sludge will catch fire at temperatures between 420 and 500 °C (788 and 932 °F). Organic materials must be completely burned at temperatures between 760 and 820°C (1400 and 1508°F).
The organic materials in sludge are transformed into oxidized end products during incineration, chiefly carbon dioxide, water vapor, and ash. The choice of treatment plan for the exhaust gases before venting them into the atmosphere, is determined by the presence of particles and other gases in the exhaust.
Conclusion
The features, volume, timing, and disposal alternatives are only a few of the variables, which affect the choice of sludge treatment procedure.
In order to get the most affordable solution, it's critical to look for a partner who can offer a full range of dewatering services, and apply the appropriate technology to your unique problems.
How can we assist?
Netsol Water is a provider of industrial and process waste pumping, dredging, sludge dewatering, and treatment services. We have seasoned engineers, project managers, operators, technicians, fabricators, scientists, mechanics, and health and safety experts on our team.
Our goal is to deliver high-calibre, secure, and economical services while exceeding clients' expectations. Some of our clients discover that the materials returned to the plant are worth enough, to cover the cost of the sludge dewatering service in part. For further information, contact us at +91 9650608473 or enquiry@netsolwater.com