8T/H Sludge Powder Organic Fertilizer Plant in Indonesia

Client Background

The client is a leading waste management company in Indonesia, seeking to expand into organic fertilizer production. Their objective was to establish a facility that:

• Converts municipal sludge into environmentally safe, nutrient-rich fertilizer
• Meets Indonesian and international organic fertilizer standards
• Minimizes odor and environmental impact through advanced waste treatment technology

After understanding the client’s requirements, our team provided a full-service solution including: process design, equipment supply, plant layout, civil construction guidance, and installation supervision.

Project Scope and Facilities

The organic fertilizer production line project is located in a suitable industrial area in Indonesia and includes the following facilities:

Utilities

• Water Supply: Connected to municipal water supply; used for both production and staff consumption
• Drainage: Rainwater and wastewater separation, treated wastewater recycled in production
• Electricity: Supplied from local grid, sufficient for full operation

Environmental Control

• Wastewater: Life sewage treated by onsite septic tanks (10m³/d capacity)
• Air Emissions: Odor collected via closed system and treated by bio-spray; 15m exhaust stack, 10,000 m³/h fan
• Noise: Equipment mounted on vibration-isolated foundations
• Solid Waste: Sludge residuals sold for further use; general waste handled by local sanitation services

Production Capacity & Standards

Quality indicators include:

• Appearance: brown granules
• Organic matter: ≥25% (C basis)
• Moisture: <10%
• Particle size: 2.5–4.5 mm
• pH: 6–7.5
• Effective microbes: ≥1×10⁸ CFU/mL
• Heavy metals within safe limits (Hg, Cd, Cr, As, Pb)

Raw Materials and Chemicals

The sludge and straw are mixed and pre-treated to ensure optimal microbial activity, efficient fermentation, and odor reduction. Fermentation agents accelerate decomposition and maintain nutrient retention.

Main Production Equipment

Production Process

This sludge powder organic fertilizer plant in Indonesia combines advanced microbial treatment, odor control, and automation to achieve high product quality and environmental compliance.

Detailed Process Flow

1. Raw Material Reception and Pre-Treatment
   • Municipal sewage sludge (<50% moisture) is delivered daily in sealed tanker trucks and discharged into the semi-underground sludge storage tank (1,000 m³ capacity, waterproof design)
   • Crop residues (rice straw, corn stalks) are received from local farms, stored in covered area, and pre-crushed to 2–3 cm pieces for easier decomposition
   • All incoming materials are logged and sampled for moisture content, heavy metals, and pathogen counts
   • Sludge is mixed with pre-crushed crop residues at a ratio of approximately 4:1 by volume to achieve optimal C:N ratio (25:1 to 30:1)
   • Fermentation agent and activator are added at this stage to jumpstart microbial activity
2. Mixing and Homogenization
   • Blended materials are transferred to the semi-closed mixer (90 kW) via belt conveyor
   • Mixing duration is 5–8 minutes per batch, ensuring uniform distribution of sludge, residues, and microbial additives
   • Moisture content is adjusted to 50–55% during mixing; if too dry, water is added; if too wet, additional dry residues are incorporated
   • Plant-based deodorant is sprayed during mixing to suppress initial odor release
   • The mixer is equipped with dust collection to capture airborne particles during operation
3. Fermentation and Curing
   • Mixed material is transported to fermentation tanks (10 t/unit, 10 units total) via closed conveyor system
   • Anaerobic fermentation is conducted at controlled temperature (55–65°C) for 8 days
   • Temperature probes monitor core temperature continuously; ventilation is adjusted to maintain thermophilic conditions
   • High temperature phase (55–65°C) ensures pathogen destruction (Salmonella, E. coli, parasitic eggs) within 3–5 days
   • Odor control: closed fermentation system captures off-gases and routes them to bio-spray treatment tower
   • After 8 days, material undergoes natural curing for an additional 4–7 days to stabilize organic matter and reduce moisture further
4. Drying and Cooling
   • Cured material is fed into the dryer (electric heating) to reduce moisture from ~35% to below 10%
   • Drying temperature is controlled at 80–100°C to preserve microbial content while achieving target moisture
   • Dried material passes through an air-cooled cooler to bring temperature down to ambient before screening
   • Cooling prevents moisture re-absorption and prepares material for efficient screening
5. Screening and Classification
   • Dried and cooled material enters the screening system with 4.5 mm mesh
   • Oversized particles (>4.5 mm) are automatically returned to the crusher for re-processing
   • On-size granules (2.5–4.5 mm) proceed to the finished product bin
   • Fines (<2.5 mm) are collected separately and can be re-introduced into the mixing stage or sold as powder fertilizer
6. Granulation and Packaging
   • On-size material is compressed and formed into uniform granules using the granulation system (if required)
   • Final product is stored in the finished product bin before packaging
   • Automatic packaging machine fills bags (typically 25 kg, 40 kg, or 50 kg) with ±0.5% weight accuracy
   • Bags are sealed, labeled with batch number, nutrient analysis, and certification marks
   • Palletized bags are stretch-wrapped and stored in warehouse for distribution

Environmental Protection Measures

Workforce & Operation

• Employees: 30 staff, single-shift operation, 2400 working hours/year
• Work Schedule: 300 working days/year
• Management: Full record-keeping of incoming sludge and chemicals, storage monitoring to prevent leaks

The 8t/h sludge powder organic fertilizer plant in Indonesia demonstrates a comprehensive solution for sustainable sewage sludge management and organic fertilizer production. Through integrated equipment, strict quality control, and environmental measures, the plant produces high-quality organic fertilizer while minimizing environmental impact. This organic fertilizer production project serves as a benchmark for future sludge-to-fertilizer projects in Indonesia and the broader Southeast Asia region.