Municipal Sludge Powder Fertilizer Production Line in Vietnam

RICHI MACHINERY

Why Vietnam? And Why Sludge-Based Fertilizer?

Vietnam’s urbanization, industrial processing and wastewater-treatment expansion are creating larger volumes of sludge that must be classified and managed correctly. For a fertilizer project, the opportunity is not simply that sludge exists; the decisive question is whether each sludge source is non-hazardous, traceable and acceptable within the registered fertilizer formulation.

The plant therefore works only with approved municipal wastewater sludge streams. QCVN 50:2013/BTNMT is relevant to hazardous-threshold classification for water-treatment sludge, but passing that classification does not by itself authorize agricultural use. The raw material must also fit the fertilizer registration, product-safety and environmental requirements that apply to the finished product.

Vietnam’s fertilizer framework has also changed. From 30 June 2026, QCVN 106:2025/BNNMT replaced QCVN 01-189:2019/BNNPTNT as the national technical regulation on fertilizer quality. Fertilizers using organic materials derived from municipal waste, food/agro-industrial waste or livestock waste are subject to specific limits for restricted elements and microbiological indicators.

Project Driver	Practical Meaning for This Plant
More wastewater treatment	Creates sludge streams requiring compliant treatment routes
Large livestock and food-processing sectors	Provide manure and controlled organic co-materials
Rice and crop-residue availability	Provides dry bulking material for aeration and carbon balance
Organic-agriculture development	Supports demand for registered organic soil inputs
Stricter waste traceability	Favors contracted sources and documented batch control

This is therefore a waste-to-resource project only when the feedstock qualification and finished-product registration both work. Sludge that is hazardous, contaminated by an industrial discharge or inconsistent with the approved formula is rejected from the fertilizer route.

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Raw Materials: What Goes Into the Fertilizer

The revised raw-material plan uses five controlled streams. The most important change is the addition of a dry structural bulking material. Municipal sludge, manure and wet organic residues alone can form a dense, low-porosity mass; rice husk, chopped straw or clean sawdust provides carbon, pore space and moisture control for aerobic composting.

Raw Material	Approx. Annual Input	Typical Receiving Condition	Function
Dewatered municipal wastewater sludge	36,000 T/A	About 65–70% moisture	Main recovered organic/mineral feedstock
Livestock manure	14,000 T/A	About 55–65% moisture	Organic matter and nutrients
Rice husk / chopped straw / clean sawdust	14,000 T/A	About 12–18% moisture	Bulking, carbon and porosity
Source-controlled food-processing residues	3,000 T/A	About 70–80% moisture	Biodegradable organic fraction
Compost inoculant / process amendment	About 200 T/A	Product-specific	Startup and process adjustment

Total gross input is approximately 67,200 T/A. Using representative moisture values, this mix contains about 30,000 tonnes of dry matter. Finished powder at 36,000 T/A and approximately 28% moisture contains about 25,900 tonnes of dry matter. The difference represents biodegradation of volatile solids and normal rejects, while roughly 27,000 tonnes of water is removed through controlled aerobic composting and curing.

The blended feed enters composting at approximately 54–58% moisture, which is much more realistic for aerobic treatment than a sludge-rich mix with no structural material. Operators adjust the proportion of rice husk, straw or sawdust according to actual sludge moisture, bulk density and pile response.

• Each sludge supplier is approved by source and treatment process, not only by price.
• Incoming sludge is sampled on a defined schedule for metals and other risk indicators relevant to the source.
• Loads showing abnormal odor, oil, solvent contamination or inconsistent solids are quarantined.
• Food-processing residues are source-separated; mixed restaurant waste is not accepted as a routine feedstock.
• Bulking materials must be clean and free from treated wood, plastic and excessive mineral contamination.

The product is described as organic powder fertilizer only after it meets the registered specification. It is not automatically called microbial or bio-organic fertilizer merely because an inoculant was used; that designation requires the relevant registered biological indicators to be demonstrated.

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The Site and Buildings (How 16,650m² Is Organized)

The 16,650 m² site is a reused industrial property rather than a greenfield fertilizer complex. Its size is justified mainly by enclosed composting, truck circulation, drainage separation and odor-control infrastructure rather than by the 6 T/H powder-finishing equipment itself.

Area	Approx. Covered Area	Main Use
Receiving and mixing building	700 m²	Sludge, manure, bulking material and mixer feed
Fermentation / curing hall	4,500 m²	Staggered aerobic composting and stabilization
Crushing and screening area	400 m²	Post-compost size reduction and recycle
Finished-product warehouse	450 m²	Short bagged-product buffer and dispatch
Office / QC / maintenance	150 m²	Laboratory, controls, spares and staff functions
Utilities / controlled waste room	50 m²	Chemical storage and maintenance waste
Total covered area	6,250 m²	Process and support buildings

The remaining site area is used for sealed truck routes, unloading control, biofilter and scrubber equipment, leachate/equalization tanks, stormwater management, fire access and future operating flexibility. The plant does not claim an arbitrary 500 m green buffer inside a 16,650 m² parcel.

Wet-material areas use sealed, chemically resistant floors with curbs and directed drainage. Clean stormwater is kept separate from process leachate. Fermentation air is maintained under controlled negative pressure so odorous air moves toward the treatment system instead of escaping through doors and roof openings.

The site was described during development as being in Binh Duong. Following Vietnam’s 2025 administrative consolidation, the former Binh Duong area is now within expanded Ho Chi Minh City, so current permits, addresses and competent-authority references should use the post-merger administrative structure.

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Equipment Configuration

This is a powder-fertilizer project, so no fertilizer pellet mill, rotary granulator, product dryer or pellet cooler is required. The main machinery is selected for wet feedstock preparation, controlled composting and final powder finishing.

Process Section	Main Equipment	Project Duty
Sludge receiving	Covered bunker / receiving hopper + screw feeder	Dewatered sludge cake handling
Manure / bulking intake	Separate hoppers and conveyors	Metered blending of wet and dry co-materials
Mixing	Twin-shaft heavy-duty mixer	Homogenizes sludge, manure, bulking material and amendments
Distribution	Reversible / traveling conveyor system	Fills compost lanes in sequence
Fermentation	Rail- or lane-mounted compost turner	Aeration and temperature control
Leachate handling	Sumps, pumps and equalization tank	Controlled recovery or treatment
Post-compost crushing	1 × 55 kW wet-material crusher	Breaks cured agglomerates
Screening	Vibrating screen + oversize recycle	Produces uniform powder
Packaging	Semi-automatic 25 / 50 kg bagging line	Approx. 6 T/H finished output
Odor control	Acid/chemical scrubber + biofilter	Approx. 50,000 m³/h captured air
Dust control	Local bag filter	Crushing, screening and bagging
Automation	PLC / MCC + temperature logging	Batch, turner and process interlocks

Because powder is the final product, the customer does not install fertilizer granulator equipment. If a future market requires pellets or granules, granulation, drying, cooling and a different packaging/storage design would be added as a separate expansion phase.

The RICHI equipment, automation and odor-control package is approximately USD 465,000. Civil rehabilitation, sealed floors, drainage, electrical work, laboratory systems, local installation, utilities and permitting sit outside that equipment figure and are included in the fixed USD 1.46 million total project investment.

The 6 T/H rating refers to cured-material crushing, screening and packaging. Receiving and composting are sized by daily wet-tonnage, residence time and bay volume; they cannot be represented accurately by the same hourly powder capacity.

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Process Flow 

The process is different from a biomass pellet production line. Moisture is retained during the biological stage, while drying and pelletizing are not normal unit operations. The key process is controlled aerobic stabilization followed by crushing, screening and packaging.

Step 1: Raw Material Intake and Mixing

Dewatered sludge arrives in sealed tipper trucks or containers rather than as a dilute liquid pumped from tankers. Loads are weighed, checked against the approved supplier list and discharged inside the enclosed receiving zone. Manure, food-processing residues and dry bulking materials enter through separate hoppers.

Feeders meter each component into the twin-shaft mixer. The operator adjusts the bulking-material proportion from actual sludge solids, moisture and pile structure; one fixed wet-weight recipe is not used for every supplier batch.

Mixing Control	Project Target
Blended moisture	Typically about 54–58%
Structure	Porous, non-pasty material that can hold free air space
C/N balance	Adjusted from actual laboratory data and bulking material
Foreign material	Removed before compost lanes
Daily gross feed	About 220–225 tonnes on operating days

Step 2: Distribution to Fermentation Hall

Mixed material is transferred by enclosed conveyors to staggered compost lanes. Lane filling is planned by batch date and feedstock source so temperatures, turning history and QC status remain traceable.

The 4,500 m² fermentation/curing hall provides the inventory volume needed for several weeks of active composting and stabilization without assuming that one small 1,728 m² hall can hold the entire daily flow.

Step 3: Fermentation (The Critical Step)

Active aerobic composting typically lasts about 14–18 days, followed by approximately 7–10 days of curing depending on temperature, oxygen demand, odor, moisture and maturity indicators. The plant does not release material solely because a fixed calendar day has been reached.

Temperature is measured at multiple points in each active lane and recorded by batch. Turning frequency is adjusted to oxygen and temperature response; it is normally more frequent during the high-rate biological phase and reduced as the material stabilizes.

• Temperature history is used as part of the hygienization record.
• Moisture is kept high enough for biological activity but low enough to preserve air space.
• Excessive ammonia indicates nitrogen loss or poor mix balance and triggers recipe/airflow adjustment.
• Anaerobic odor or black wet zones trigger additional turning and bulking-material correction.
• Maturity is confirmed by stable temperature, odor, respiration/plant response or another validated QC method.

The enclosed hall operates under controlled extraction. Approximately 50,000 m³/h of captured air passes through a scrubber for ammonia/acid-gas control and then a biofilter sized from actual air flow and media loading. Activated carbon or other polishing can be added only if monitoring shows it is necessary.

Step 4: Discharge from Fermentation Hall

Cured material is removed by loader or discharge conveyor and transferred to the powder-finishing section. Leachate and wash water are collected separately from clean stormwater; suitable process liquid can be returned to the mixer only when its quality and moisture balance allow.

Step 5: Crushing (Breaking Agglomerates)

The wet-material crusher breaks cured lumps rather than pulverizing the compost. A 55 kW machine provides approximately 6–8 T/H depending on moisture, fiber content and agglomerate size. The crusher is selected for moist organic material and a larger opening than dry feed-grain milling.

Step 6: Screening

A vibrating screen removes oversize material and sends it back to the crusher or compost rework stream. The commercial powder is normally controlled to pass a project-selected top screen, typically around 6–8 mm, with final particle condition defined by the registered product specification.

The client does not use an organic fertilizer pellet making machine in this phase. Powder avoids granulation, drying and cooling, but it still requires moisture control and free-flowing handling to prevent bridging in hoppers and bags.

Step 7: Finished Product Storage

Screened product enters a low-profile surge hopper and then moves to bagging. Finished material is not held for long periods at elevated moisture; warehouse turnover is coordinated with QC release and delivery schedules.

Finished Product Control	Project Release Basis
Form	Screened organic powder
Moisture	Typically about 25–30%
Organic matter	At or above the registered value; current QCVN 106 organic-fertilizer category requires at least 20% for basic organic fertilizer
Arsenic	Within current QCVN 106 limit; ≤10 mg/kg for relevant organic/waste-derived fertilizers
Mercury	Within current QCVN 106 limit; ≤2 mg/kg for relevant category
Cadmium	Within current QCVN 106 limit; ≤5 mg/kg for relevant category
Salmonella spp.	Not detected /25 g where the waste-derived organic-fertilizer rule applies
E. coli	Below the current QCVN 106 microbiological limit

N, P and K are declared only at values demonstrated by testing and recognized in the product registration. The plant does not assume every sludge/manure blend will automatically deliver 5–6% total NPK.

Step 8: Packaging

Released product is packed in 25 kg or 50 kg woven bags with an inner moisture barrier when required by the customer. A semi-automatic scale, bag closer, conveyor and pallet wrapping system are adequate for the 6 T/H output.

Each dispatch lot is linked to incoming sludge sources, compost lane records, processing date and laboratory release results. Product that fails a safety criterion is quarantined; it is not diluted into a new batch or relabeled as soil conditioner to bypass fertilizer requirements.

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Quality Control Laboratory

The on-site laboratory is used for rapid production control, while accredited external laboratories are used for tests that require validated instrumental methods or official conformity evidence. This is particularly important for sludge-derived fertilizer because heavy metals and microbiological safety cannot be managed by visual inspection.

Control Item	Routine Frequency	Typical Route
Incoming moisture / solids	Each delivery or composite lot	On-site oven / moisture method
pH / conductivity	Each process batch	On-site
Compost temperature	Multiple readings daily	On-site probes + batch log
Organic matter / nutrient trend	Scheduled composite batches	On-site screening + accredited confirmation
As, Hg, Pb, Cd and other required metals	Supplier qualification + periodic finished product	Accredited laboratory
Salmonella / E. coli	Finished-product release program	Accredited microbiology laboratory
Maturity / stability	Each compost batch	Validated internal method
Retained sample	Each released lot	Stored by defined traceability procedure

A portable XRF instrument can be useful for screening some metals, but it is not treated as the sole legal release method for every element or matrix. Supplier certificates, representative sampling and accredited laboratory confirmation remain part of the control plan.

The laboratory area therefore focuses on sample preparation, moisture, pH and routine process measurements. More complex metals and microbiological analyses are outsourced when required. This avoids claiming that a small plant laboratory can reliably quantify every trace contaminant with basic equipment.

Chemical waste from digestion reagents, standards and contaminated consumables is kept in labeled compatible containers within a controlled storage area and transferred to an authorized waste contractor. The project does not assume several tonnes of laboratory hazardous waste from a small QC workload without supporting records.

QCVN 106:2025/BNNMT is the current fertilizer-quality basis from 30 June 2026. TCVN 7185:2002 remains a standard for microbial organic fertilizer, but it applies specifically when selected living microorganisms are part of the marketed product; it is not the default standard for every composted sludge powder.

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Utility Requirements and Consumption

The plant’s largest continuous electrical load is ventilation and odor control, not the 6 T/H crusher. Compost turning, mixing and powder finishing operate intermittently, while negative-pressure extraction and environmental systems run whenever odorous material is present.

Utility	Practical Annual Use	Planning Basis
Electricity	Approx. 1.1–1.4 million kWh/year	Mixing, turner, ventilation, crusher, screening, packing and buildings
Electrical service	Approx. 315–400 kVA	Allows process and odor-control loads with starting margin
Fresh water	Approx. 2,500–3,500 m³/year	Scrubber make-up, cleaning, lab and domestic use
Diesel	Approx. 10,000–14,000 L/year	Loader, forklift and yard handling
Process heat	Not normally required	No product dryer in the base process

The scrubber operates with recirculation, but make-up and controlled blowdown are still required. Forty cubic metres of water per year would not be credible for a continuously operated scrubber plus cleaning, laboratory and staff use.

Leachate and dirty wash water are collected in a process-water system and reused only when quality and compost moisture allow; excess water is treated or managed under the site’s environmental permit. Clean stormwater is routed separately so the plant does not rely on an unrealistic blanket ‘zero discharge’ claim.

A workforce of approximately 26–30 people is used in the project plan. Fermentation ventilation runs around the clock, while receiving, powder finishing and bagging are scheduled around incoming trucks and the 20 effective production hours required to achieve about 36,000 T/A.

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Environmental Compliance 

Compliance is handled through feedstock classification, the project’s environmental approval/permit, controlled emissions and fertilizer registration. The regulatory route is not reduced to three generic permits or a single set of stack limits copied from another industry.

QCVN 50:2013/BTNMT is used to determine hazardous thresholds for sludge from water-treatment processes. A sludge stream that is classified as hazardous is not accepted into this fertilizer process. Non-hazardous classification, however, is only the first gate; the finished fertilizer must separately comply with its recognized circulation/quality requirements.

For industrial exhaust, QCVN 19:2024/BTNMT took effect on 1 July 2025 with transitional provisions for existing approved projects. The applicable emission values depend on the source, project status and permit basis, so this page does not publish invented particulate, NH3, H2S, VOC or odor monitoring results.

Environmental Area	Project Control
Odor / ammonia	Enclosed receiving + negative-pressure hall + scrubber + biofilter
Powder dust	Local bag filtration at crusher, screener and packing
Leachate	Curbed floors, collection sumps and process-water tank
Stormwater	Separated clean drainage from process wastewater
Rejected feedstock	Quarantine and return / authorized waste route
Hazardous maintenance / lab waste	Controlled storage + licensed contractor
Noise	Equipment enclosure and current local/national noise requirements
Monitoring	Permit-based air, water, waste and operating records

The administrative authority also changed after the 2025 merger of Binh Duong, Ba Ria–Vung Tau and Ho Chi Minh City. Current environmental documents should therefore use the competent agencies of expanded Ho Chi Minh City rather than referring indefinitely to Binh Duong DONRE as a current provincial authority.

The plant does not claim zero waste to landfill as an absolute achievement. Clean screen oversize can return to processing, but contaminated rejects, unsuitable sludge, spent filter media or hazardous residues follow the legally required disposal route.

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How RICHI Machinery Customized This Line

The process was customized around four constraints: variable dewatered sludge, powder rather than granules, a fixed existing site and the need to control odor without making the biological process overly complex.

1. RICHI added dry bulking-material dosing so the mixer can correct porosity and moisture instead of relying on sludge plus manure alone.
2. Receiving uses separate wet and dry routes, with covered sludge handling and controlled drainage.
3. The fermentation hall is divided into traceable staggered lanes so incoming batches do not mix indiscriminately.
4. The project ends at crushing, screening and packaging; pelletizing, drying and cooling are excluded from the base line.
5. Odorous air is captured from receiving and fermentation and routed through a scrubber/biofilter system sized around the actual exhaust volume.
6. Automation records mixer batches, temperature history, turner schedules and finished-lot identification.

The powder line is intentionally simpler than a granulated organic-fertilizer plant, but the sludge route requires more environmental and QC engineering. RICHI therefore concentrates engineering on material consistency, compost aeration, wet-material conveying, odor capture and safe finished-product release.

The scope covers process engineering, equipment manufacture, factory inspection, export packing, controls integration, installation guidance, commissioning and operator training. Local contractors execute civil rehabilitation, drains, electrical installation and environmental works under the approved site design.

Equipment can be shipped from Qingdao to a southern Vietnam gateway such as Cat Lai / Ho Chi Minh City port facilities and then moved by road to the site. The final route is selected from cargo dimensions, port schedule, customs and local access conditions.

A comparable project normally needs about 6–9 months from design freeze to commissioning when environmental approvals, building rehabilitation and equipment manufacture proceed in parallel.

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Market Outlook for Organic Fertilizer from Sludge in Vietnam

Vietnam has a clear policy direction toward organic agriculture, circular use of agricultural residues and lower dependence on purely inorganic inputs. That supports demand for registered organic fertilizers, but sludge-derived products face a higher trust and testing burden than manure- or crop-residue-based compost.

The project’s market therefore starts with buyers who value documented quality: commercial farms, soil-improvement contractors, landscaping users and fertilizer distributors that can review batch test data. The plant does not assume that sludge-derived fertilizer is automatically accepted by certified organic farms.

The current fertilizer-quality framework is also more specific than the previous page suggested. QCVN 106:2025/BNNMT has applied since 30 June 2026, and fertilizer is subject to a 5% VAT rate under Vietnam’s current VAT framework rather than a blanket 0% rate.

Market Factor	What It Means for the Client
Low-cost waste feedstock	Useful only when testing and treatment costs are controlled
Competing manure/crop-residue compost	Requires transparent quality and traceability
Seasonal farm demand	Needs flexible warehouse and distributor planning
Urban / industrial waste-service contracts	Can provide a second revenue logic separate from fertilizer sales
Current contaminant limits	Favor stable, well-controlled municipal sludge sources over mixed industrial sludge

The project is therefore positioned as a regional resource-recovery facility with fertilizer sales, not as a guaranteed high-margin fertilizer factory. Gate fees, sludge transport, testing, bulking-material cost, odor treatment, packaging and distributor discounts all influence economics.

Expansion should follow secured sludge contracts and repeat product acceptance. A second plant in another province or region should not be assumed until feedstock qualification, environmental permitting and local fertilizer demand have been verified.

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Thinking About a Sludge-to-Fertilizer Project?

The most important lesson from this organic fertilizer production project is that sludge quality determines whether the project is a fertilizer business at all. Equipment cannot correct hazardous contamination after it has entered the feedstock.

Start with solids content, contamination history and source type. Municipal biological sludge, mixed industrial sludge and septic sludge are not interchangeable. Each has different metals, organics, pathogens, moisture and regulatory implications.

Design the compost recipe around air space as well as nutrients. A sticky sludge/manure blend needs a structural carbon source such as rice husk, straw or clean sawdust; otherwise larger mixers and turners will not solve oxygen limitation inside the pile.

Odor control should be designed from captured airflow and contaminant load. Enclosure and negative pressure are usually more effective than trying to treat diffuse open-yard emissions after they have escaped.

Powder is appropriate when the customer accepts it, but it is not automatically easier to store. Moist compost powder can bridge, cake and heat if insufficiently mature. Final moisture, maturity and warehouse residence time still need control.

For Vietnam projects, use the current fertilizer-quality and environmental rules in force at the time of commissioning. The regulatory framework changed materially in 2025–2026, so older references should not be reused without verification.

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Considering a Sludge Processing or Organic Fertilizer Project?

A sludge fertilizer project should begin with laboratory data and legal classification, not with the hourly capacity of a crusher or compost turner.

1. Identify each sludge source and whether industrial wastewater enters the municipal system.
2. Obtain representative moisture, solids, organic matter, metals and microbiological data.
3. Confirm the sludge is non-hazardous under the applicable waste-classification framework.
4. Define the finished fertilizer category and the current registration / quality limits before fixing the recipe.
5. List available manure, rice husk, straw, sawdust or other bulking materials by season.
6. Provide site area, building height, drainage, neighboring receptors and available electrical capacity.
7. Define whether the commercial product is powder or granulated fertilizer before selecting downstream equipment.

A 6 T/H powder section does not by itself dictate a minimum 10,000 m² site. Required land depends far more on wet-feed tonnage, compost residence time, pile depth, receiving/storage policy, odor enclosure and truck circulation.

RICHI can configure an Organic fertilizer production line around the actual waste analysis and registered product route, including fermentation, wet-material crushing, screening and packaging, with granulation added only where the market and product specification justify it.