To learn more about the characteristics and effective methods for treating sludge, let's explore the article below with Nanoen!
A. CHARACTERISTICS OF SLUDGE
1. Organic matter content:
Sludge contains a high level of organic matter from biological or chemical sources.
Sludge can harbor abundant organic matter and nutrients, creating a valuable resource for producing organic fertilizers. However, sludge also has disadvantages and challenges when used as fertilizer, as follows:
-
Odor:
-
Sludge often emits an odor due to the decomposition of organic matter and the presence of gases such as methane and hydrogen sulfide.
-
The odor not only causes discomfort but also pollutes the surrounding air environment.
-
Bacteria and diseases:
+ Sludge contains various bacteria and microorganisms, some of which can cause diseases and environmental pollution.
+ Bacteria in sludge can pose risks to human and animal health if not properly treated.
-
High moisture content and difficult transportation:
-
Sludge contains a lot of water, resulting in high moisture content and free-flowing ability, making transportation difficult.
-
High moisture content also increases the weight and reduces the efficiency of use in the treatment and utilization of sludge.
-
Fresh sludge, immediately after collection and without treatment, is not recommended for direct use as fertilizer.
Read more: Aerobic granular sludge
2. Industrial wastewater sludge:
Can contain high levels of heavy metals such as copper (Cu), chromium (Cr), arsenic (As), nickel (Ni), cadmium (Cd), and other heavy metals. These heavy metals can pose environmental and human health risks if not properly treated.
Sludge Storage Tank
Source: Nano Environment Company; photo taken from actual project
3. The Weight and Density of Sludge Generated during Wastewater Treatment
B. METHODS OF SLUDGE TREATMENT
-
Sludge treatment by sludge thickening tank:
The sludge thickening tank operates on a principle similar to that of a circular settling tank. Accordingly, the sludge-containing solution enters the central pipe area of the tank. Due to the gravitational force in a static environment, the sludge in the water settles to the bottom. The clean water above flows out through the channels around the tank and continues to be treated.
Some systems with large capacities also feature sludge scrapers in the central bottom area. As the sludge settles downward, the sludge scraper arms push them to the tank bottom more rapidly. From this area, the sludge is then pumped into the sludge press.
Additionally, to create gaps and movement on the surface, rake arms of the scraper machine are attached from wooden or steel bars. When the machine rotates around the axis, these vertical bars stir the sludge mass, causing the water to overflow, making the sludge denser.
-
Sludge treatment by sludge drying bed:
A sludge drying bed is considered a stage to dry the sludge, reducing its moisture content to around 70 – 80%, meaning the dry matter content of the sludge increases by 20 – 30%.
A sludge drying bed is an enclosed area lined with impermeable materials or reinforced concrete. The bottom is lined with various sizes of stones to facilitate water drainage, above which a layer of sand is placed. The top porous layer is used to contain the sludge to be dried.
However, sludge drying beds occupy a relatively large area; therefore, this stage is only suitable for locations with ample space. Leachate from the sludge can pollute groundwater, so drying beds should be constructed in areas where the groundwater level is at least 1 meter below the ground level.
-
Sludge stabilization by anaerobic digestion:
This is a method of stabilizing sewage sludge and can reduce volume, stabilize sludge characteristics, and reduce pathogenic microorganisms in sewage sludge.
The anaerobic digestion process can be divided into several steps. The anaerobic digestion of sewage sludge takes place over a long period and at a relatively stable total temperature, typically at 35°C for 20 days to achieve results in disinfection and optimal methane production. Anaerobic digestion technology can yield a large amount of methane gas; however, the long duration requires the installation of large treatment tank systems, and the waste of this system still requires appropriate treatment technology such as landfilling or reuse as fertilizer.
-
Aerobic digestion:
The digestion process is carried out by aerobic microorganisms involved in decomposing organic matter and generating heat. The digestion temperature can reach 70°C. Typically, for aerobic digestion treatment, the sludge temperature can reach 50-65°C after 5 – 6 days, so pathogenic bacteria will be destroyed. The operational costs for aerobic digestion treatment are higher than those for anaerobic digestion treatment, but the time required is shorter. Similar to anaerobic digestion technology, the waste after aerobic digestion still requires suitable treatment technology such as landfilling or reuse as fertilizer.
Read more: Difficult to settle sludge and floating sludge reoccurrence
-
Sludge Treatment by Sludge Dewatering Machine:
The sludge dewatering machine is used in the final stage of the wastewater treatment process, playing a role in compacting liquid sludge into cake sludge with a certain degree of dryness, helping to minimize the pollution concentration of the water filtered out during the sludge dewatering process.
However, currently, the cost of sludge dewatering machines on the market is quite high. Additionally, during the operation of the sludge dewatering machine, there are cases where troubleshooting takes a considerable amount of time for repair and warranty, causing difficulties in the waste treatment process. Therefore, renting sludge dewatering machines has become a useful solution for businesses in waste treatment. Not only does it solve the problem of machinery and time, but our sludge dewatering machine rental service also saves costs for investors.
Source: Nano Environmental Company; photo taken from a real project
The unit providing sludge dewatering rental services in the Mekong Delta
Nanoen is a reputable provider of sludge dewatering rental services in the Mekong Delta region, committed to providing businesses with all necessary legal documentation for sludge treatment activities, along with the best rental prices in the market. Moreover, the rental process is ensured to be efficient, with streamlined procedures, minimal labor requirements, and maximum time savings for customers.
Source: Nano Environmental Company; photo taken from a real project
With experienced staff, Nanoen offers comprehensive services from environmental dossier consulting to design and construction, operation of environmental treatment systems, provision of microbial products, and sludge dewatering services.
Nanoen is committed to providing the best service experience tailored to the needs of customers.
Nanoen
Address: 661E/29, Vo Van Kiet Street, Binh Yen A Quarter, Long Hoa Ward, Binh Thuy District, Can Tho City
Hotline: 0941.777.519 - 0907.803.678 - 0901.229.798
Email: nanoentech@gmail.com
Facebook: www.facebook.com/nanoentech
