600m³/day Cheese Factory Wastewater Treatment Project Case

1. Case Basic Information

1.1 Project Subject

• Provider: HELLA WATER, a trusted supplier of high-performance water treatment product, specializes in customized industrial wastewater treatment solutions for food processing industries.
• Project Name: Tunisia 600 Tons/Day Cheese Production Wastewater Treatment Project
• Core Objective: Treat high-concentration organic wastewater from cheese production to meet local discharge standards (DB 37/599-2006), realize energy recovery (biogas utilization), and minimize environmental impact.

1.2 Treatment Scale & Water Quality Parameters

Inlet Water Quality (Comprehensive Production Wastewater)

Parameter	Value
CODcr	21800 mg/L
BOD₅	9600 mg/L
Suspended Solids (SS)	1600 mg/L
Kjeldahl Nitrogen	298 mg/L
Total Phosphorus	164 mg/L
Oil	250 mg/L
Detergent	4.1 mg/L
pH	3.2 (acidic)

Effluent Discharge Standard (Local Requirements)

Parameter	Value
CODcr	≤200 mg/L
BOD₅	≤50 mg/L
SS	≤50 mg/L
Kjeldahl Nitrogen	≤5 mg/L
Total Phosphorus	≤2 mg/L
Oil	≤10 mg/L
Detergent	≤1 mg/L
pH	6.5-9.0

1.3 Core Equipment & Process Configuration

Process Unit	Key Equipment	Specifications	Quantity
Pretreatment	Mechanical Grille + Dissolved Air Flotation Machine	Hydraulic curved screen; PAM/PAC dosing device	1 set (grille), 1 set (flotation machine)
Regulation & Neutralization	pH Adjustment Pool + Equalization Tank	Semi-underground steel-concrete structure; Effective volume: 200 m³	1 set each
Anaerobic Treatment	UASB Anaerobic Reactor	Volume: 180 m³; Volume load: 5-10 kgCOD/m³·d	1 unit
Aerobic Treatment	Multi-stage A/O Reaction Tank	Level I A/O: 1200 m³; Level II A/O: 500 m³; Tubular microporous aerator	1 set
Solid-Liquid Separation	Secondary Sedimentation Tank	Surface load: 8 m³/m²·h; Total volume: 800 m³	1 unit
Sludge Treatment	Spiral Dewatering Machine + Sludge Thickener	DYLT-301 type; PAM dosing device (JY-500)	1 set each
Energy Recovery	Biogas Collection & Purification System	Desulfurization tower + gas storage tank + flame arrester	1 set
Automatic Control	PLC Control System + Online Monitors	DO, pH, level, flow rate monitors; Central control cabinet	1 set

1.4 Design Standards & Compliance

The project adheres to industry core standards and regulations, including:

• DB 37/599-2006: Local Wastewater Discharge Standard
• GBJ 14-87 (1997 edition): Code for Design of Outdoor Drainage
• GBJ 13-86: Outdoor Water Supply Design Code
• GB 141-90: Code for Structural Design of Water Supply and Drainage Engineering
• JB2932-1999: Technical Specifications for Water Treatment Equipment
• ISO9001: Quality Management System Certification

1.5 Application Scenarios

• High-concentration organic wastewater treatment in dairy/cheese factories
• Food processing industry wastewater purification (containing proteins, fats, sugars)
• Industrial wastewater treatment projects requiring energy recovery (biogas)
• Acidic wastewater treatment with corrosion protection requirements
• Compliance-oriented wastewater treatment in regions with strict discharge standards

2. Project Core Pain Points & Requirements

2.1 Industry Common Pain Points

1. High Pollution Load: Cheese wastewater is high-concentration organic wastewater (COD up to 21800 mg/L) with high nitrogen and phosphorus, leading to severe eutrophication if discharged directly.
2. Acidic Corrosion: pH=3.2 acidic wastewater corrodes equipment and pipelines, requiring special anti-corrosion treatment.
3. Ammonia Nitrogen Surge: Anaerobic treatment of protein-rich wastewater increases ammonia nitrogen concentration (200-600 mg/L), making denitrification difficult.
4. Large Sludge Production: Traditional processes generate massive sludge, increasing disposal costs and secondary pollution risks.
5. High Operating Costs: Aerobic treatment of high-concentration wastewater consumes excessive energy; lack of resource recovery leads to waste.

2.2 Customer Core Requirements

• 达标排放: Efficiently remove COD, BOD, ammonia nitrogen, and phosphorus to meet local discharge standards.
• Corrosion Resistance: Ensure equipment and structures withstand acidic wastewater and long-term stable operation.
• Energy Recovery: Utilize biogas generated from anaerobic treatment to reduce energy consumption and operating costs.
• Sludge Reduction: Minimize sludge production and simplify sludge disposal to lower environmental and economic burdens.
• Intelligent Operation: Realize automatic control of pH, flow rate, and aeration to reduce manual intervention.

3. Hella Water Customized Solutions

3.1 Process Design: Anaerobic-Aerobic Integration + Energy Recovery

The solution adopts a “Pretreatment → Regulation & Neutralization → UASB Anaerobic → Multi-stage A/O → Solid-Liquid Separation → Disinfection” integrated process, combined with biogas energy recovery:

1. Pretreatment Stage:
   • Mechanical Grille: Removes large suspended solids (e.g., cheese residues, fibers) to protect subsequent equipment.
   • Dissolved Air Flotation Machine: Cooperates with chemical dosing system (PAM/PAC) to remove 85% of oil and 90% of SS, reducing the burden on biological treatment.
2. Regulation & Neutralization Stage:
   • Equalization Tank: Balances water quality and quantity (retention time: 5h) to mitigate impact loads; adjusts pH by recycling effluent (no additional neutralizer needed during stable operation).
   • pH Adjustment Pool: Temporarily adjusts acidic wastewater during commissioning to ensure suitable conditions for anaerobic/aerobic microorganisms.
3. Anaerobic Treatment Stage (Energy Recovery):
   • UASB Anaerobic Reactor: Degrades 60-70% of COD through hydrolysis, acidification, and methanogenesis; generates biogas (methane content ≥65%).
   • Biogas Utilization: Biogas is purified (desulfurization + dehydration) and used for boiler combustion, power generation, or factory canteen use, reducing energy costs by 30%.
4. Aerobic Treatment Stage (Deep Purification):
   • Multi-stage A/O Reaction Tank:
     • Level I A/O: Denitrification with organic carbon sources in wastewater; reduces nitrate nitrogen to N₂.
     • Level II A/O: Nitrification (DO=2-3 mg/L) converts ammonia nitrogen to nitrate nitrogen; realizes deep denitrification and phosphorus removal.
     • Tubular microporous aerators ensure high oxygen transfer efficiency, reducing aeration energy consumption.
5. Solid-Liquid Separation & Sludge Treatment:
   • Secondary Sedimentation Tank: Separates activated sludge from treated water; sludge reflux to A/O tank maintains microbial concentration.
   • Spiral Dewatering Machine: Dewaters excess sludge (moisture content ≤60%); granular sludge from UASB is sold as commercial inoculant, realizing resource utilization.

3.2 Core Technical Advantages

Technical Highlight	Description
High-Efficiency Anaerobic-Aerobic Synergy	UASB removes most COD (energy-saving) + multi-stage A/O achieves deep denitrification; total COD removal rate ≥99%, ammonia nitrogen removal rate ≥98%.
Corrosion Protection Design	Steel-concrete structures with fiberglass lining; acid-resistant pumps/pipelines; adapts to pH=3.2 acidic wastewater.
Energy Recovery	Biogas generation (≈0.5 m³ biogas/kgCOD degraded) reduces energy consumption by 30-40% compared to traditional processes.
Sludge Reduction	Anaerobic sludge production (0.05 kg/kgCOD) is 1/10 of aerobic processes; granular sludge recycling reduces disposal costs.
Intelligent Control	PLC automatic control of pH, flow rate, and aeration; online monitors (DO, pH, level) trigger alarms and adjust parameters in real time.

3.3 Key Supporting Systems

• Pre treatment filtration system: Grille + flotation machine ensures inlet water quality for UASB and A/O systems.
• Anti-corrosion System: Fiberglass lining for tanks, acid-resistant pipelines/pumps, and stainless steel components to extend service life.
• Emergency Protection: Overflow pipes and accident tanks prevent untreated wastewater discharge during equipment failure.

4. Project Effectiveness Verification

4.1 Pollutant Removal Efficiency

Pollutant	Inlet Concentration	Effluent Concentration	Removal Rate
CODcr	21800 mg/L	≤200 mg/L	≥99.1%
BOD₅	9600 mg/L	≤50 mg/L	≥99.5%
SS	1600 mg/L	≤50 mg/L	≥96.9%
Kjeldahl Nitrogen	298 mg/L	≤5 mg/L	≥98.3%
Total Phosphorus	164 mg/L	≤2 mg/L	≥98.8%
Oil	250 mg/L	≤10 mg/L	≥96.0%

4.2 Operational Performance

• Stability: Continuous operation for 8000 hours with stable effluent quality; adapts to ±30% flow fluctuations and ±25% COD concentration changes.
• Energy Efficiency: Biogas generation ≈10,900 m³/d (based on 21800 mg/L COD); annual energy saving ≈360,000 kW·h, reducing operating costs by USD 36,000 (0.1 USD/kW·h).
• Sludge Reduction: Annual sludge production ≤150 tons (moisture content 60%), 70% less than traditional aerobic processes.
• Corrosion Resistance: No equipment corrosion reported after 2 years of operation; anti-corrosion components maintain good performance.

4.3 Economic & Environmental Benefits

• Economic Benefits: Annual energy savings USD 36,000; sludge disposal cost reduction USD 20,000; granular sludge sales income USD 15,000; total annual economic benefit ≈USD 71,000.
• Environmental Benefits: Annual reduction of COD emission by ≈7,900 tons; ammonia nitrogen emission by ≈107 tons; phosphorus emission by ≈60 tons; biogas utilization reduces greenhouse gas (methane) emission.

5. Case Corresponding Product Quotation Description

5.1 Quotation Overview

Item	Description	Total Amount (USD)
Core Equipment	UASB reactor, multi-stage A/O tank, flotation machine, sludge dewatering system	Included in total
Auxiliary Systems	Biogas purification system, automatic control system, online monitors	Included in total
Engineering Design & Installation	Civil construction design, equipment installation, pipeline connection	Included in total
Total Project Quotation	–	2,171,450

5.2 Quotation Terms

Term Type	Details
Validity Period	45 working days from the date of quotation
Payment Terms	Negotiable (reference: 30% advance payment, 40% during construction, 30% after acceptance)
Project Cycle	7 months (1 month design + 3 months civil construction + 2 months equipment installation + 1 month commissioning)
Warranty Period	12 months from the date of acceptance (free repair/replacement for non-human damage)
Incoterms	DAP (Delivered at Place, Tunisia)
Additional Services	Free operator training (2-3 personnel); 24/7 online technical support

5.3 Additional Notes

• The quotation includes equipment, design, installation, and commissioning; civil construction materials (steel, concrete) are excluded.
• Spare parts (aerators, pumps, filters) are provided at 15% of the equipment price for long-term supply.
• Biogas utilization system can be customized (power generation/boiler combustion) based on factory needs.

6. Frequently Asked Questions (FAQ)

6.1 Installation & Commissioning

Q: What are the on-site installation requirements for the UASB reactor?

A: The UASB reactor requires a flat foundation with load-bearing ≥5 tons/m²; installation space ≥10m×6m×8m (length×width×height). It needs to be connected to biogas storage and purification facilities; we provide detailed installation drawings and dispatch 2-3 engineers for on-site guidance. Commissioning takes 1 month, including granular sludge inoculation and system stabilization.

6.2 Maintenance & Upkeep

Q: How often does the UASB reactor and A/O tank require maintenance?

A: Routine maintenance includes: 1) UASB reactor: Check three-phase separator and water distributor every 3 months; desulfurize biogas system every 6 months. 2) A/O tank: Clean aerators every 6 months; replace worn aerator membranes every 2 years. 3) Sludge dewatering machine: Clean screw shaft every week; replace filter screen every 1 year.

Q: What is the service life of core equipment?

A: UASB reactor (15-20 years), multi-stage A/O tank (15 years), biogas purification system (10 years), sludge dewatering machine (8-10 years). We provide lifelong technical support and preferential spare parts supply.

6.3 Warranty & After-Sales

Q: What is covered under the 1-year warranty period?

A: Within the warranty period, we provide free repair or replacement for faults caused by design, manufacturing, or material defects, including core equipment (UASB reactor, A/O tank, control system), pumps, aerators, and monitors. Damage from improper operation, corrosion due to non-compliant water quality, or natural disasters is not covered.

Q: How to get after-sales technical support for overseas projects?

A: We provide 24/7 online support via email and video calls; for urgent on-site issues, technicians can be dispatched to Tunisia within 72 hours (additional fees apply for international travel). We also conduct semi-annual return visits to monitor system operation.

6.4 Operational Cost

Q: What is the estimated monthly operating cost of the system?

A: The main operating costs include electricity (aeration, pumps), chemicals (PAM/PAC), and labor. For a 600m³/d system, the monthly electricity cost is about USD 4,500 (excluding biogas energy savings), chemical cost about USD 1,200, and labor cost about USD 2,000. With biogas energy savings (≈USD 3,000/month), the net monthly operating cost is ≈USD 4,700.

6.5 Safety & Compliance

Q: Is biogas utilization safe, and how to prevent explosion risks?

A: Yes. The biogas system is equipped with desulfurization towers (removes H₂S), flame arresters, and pressure relief valves. The gas storage tank is installed in an open area ≥10m away from buildings; online biogas flow monitors trigger alarms for abnormal pressure. We provide safety training for operators to ensure compliant use.

Q: How to handle sudden increases in ammonia nitrogen concentration?

A: The multi-stage A/O system has strong shock resistance; the PLC control system automatically increases the nitrification liquid reflux ratio (up to 300%) and adjusts aeration intensity to enhance denitrification. If ammonia nitrogen exceeds 500 mg/L, the system activates emergency dosing of external carbon sources (e.g., methanol) to ensure effluent compliance.