100m³/day Kitchen and Bathroom Wastewater Reuse System Project Case

1. Case Basic Information

1.1 Project Subject

• Provider: HELLA WATER, a professional supplier of high-performance water treatment product, specializes in customized wastewater reuse solutions for commercial and residential scenarios.
• Core Product: 100m³/day Integrated Kitchen and Bathroom Wastewater Reuse System (combines A/A/O biochemical treatment, MBR membrane separation, and reverse osmosis technology)
• Project Objective: Treat 100m³/day of kitchen and bathroom wastewater to realize resource reuse (e.g., toilet flushing, greening irrigation, cleaning), achieving water conservation and environmental protection.

1.2 Treatment Scale & Water Quality Parameters

Inlet Water Quality

Parameter	Value
Turbidity	<100 NTU
Total Suspended Solids (TSS)	<150 mg/L
Fats and Oils	<10 mg/L
Chlorine	<1 mg/L
BOD₂₅	<300 mg/L
COD	<500 mg/L
TOC	<15 mg/L
pH	6.5 – 8.5

Effluent Water Quality (Reuse Standard)

Parameter	Value
Turbidity	<1 NTU
TSS	<5 mg/L
COD	<30 mg/L
BOD₂₅	<5 mg/L
Ammonia Nitrogen	<1 mg/L
Total Coliforms	<10 CFU/100mL
pH	6.5 – 8.5
Reuse Rate	≥80%

1.3 Core Equipment Specifications

Equipment Module	Specifications	Quantity
Integrated Wastewater Treatment Device	Size: 12m×2.4m×2.55m; Material: Carbon steel; Includes anoxic tank, anaerobic tank, aerobic tank, sedimentation tank, MBR membrane, disinfection tank	1 set
Reverse Osmosis (RO) Machine	Size: 3m×1m×2.2m; High-pressure pump power: 5.5kW; Membrane element: 8040 type (DOW composite membrane)	1 set
Pretreatment Equipment	Artificial grille (600×600mm), equalizing tank lift pump (QW10-10-0.75)	1 set (grille), 2 pcs (pumps)
Aeration & Control System	Roots blower (4kW, 2 pcs), full-specification electrical control box, liquid level controller	1 set (blower), 1 set (control system)
Disinfection Equipment	Chlorine dioxide disinfection dosing device (LR-100)	1 set

1.4 Design Standards & Compliance

The system adheres to industry core standards and quality requirements, including:

• GB 50335-2016: Code for Design of Building Water Supply and Drainage and Heating Engineering
• GB/T 18920-2022: Reclaimed Water for Urban Miscellaneous Use
• JB2932-1999: Technical Specifications for Water Treatment Equipment
• JC692: Technical Requirements for Reverse Osmosis Water Treatment Equipment
• ISO9001: Quality Management System Certification

1.5 Application Scenarios

• Wastewater reuse in commercial buildings (hotels, office buildings, shopping malls)
• Residential community kitchen and bathroom wastewater recycling
• Greening irrigation and road cleaning in industrial parks
• Supplementary water for landscape water bodies
• Small-scale municipal wastewater reuse projects, aligning with agricultural water purification for non-edible crop irrigation

2. Project Core Pain Points & Requirements

2.1 Industry Common Pain Points

1. Complex Pollutant Composition: Kitchen and bathroom wastewater contains fats, oils, suspended solids, and high-concentration organic matter (BOD/COD), which are difficult to treat with simple processes.
2. Water Quality Fluctuations: Wastewater discharge varies with usage peaks (e.g., morning and evening), leading to impact loads on treatment systems.
3. Low Reuse Rate: Traditional treatment only achieves discharge standards, wasting water resources; lack of deep treatment technology for reuse.
4. Large Footprint & High Labor Cost: Split-type equipment occupies significant space; manual operation and maintenance require professional personnel.
5. Odor & Sludge Issues: Anaerobic decomposition of organic matter produces odors; excess sludge increases disposal costs.

2.2 Customer Core Requirements

• Deep Purification: Efficiently remove fats, oils, organic matter, and pathogens to meet reuse standards for multiple scenarios.
• High Reuse Rate: Achieve ≥80% wastewater reuse to save freshwater resources and reduce water fees.
• Intelligent & Compact Design: Integrate multiple functions, reduce footprint, and realize automatic operation to minimize manual intervention.
• Stable Operation: Adapt to water quality/quantity fluctuations and ensure consistent effluent quality.
• Low Operating Cost: Reduce energy consumption, chemical dosage, and sludge production to lower long-term operating costs.

3. Hella Water Customized Solutions

3.1 Process Design: Integrated A/A/O-MBR-RO Deep Treatment Technology

The solution adopts a “Grille → Regulating Pond → Hydrolysis Acidification Tank → A/A/O Biochemical Pool → MBR Membrane Separation → Reverse Osmosis (RO) → Disinfection” integrated process, realizing full-process wastewater purification and reuse:

1. Pretreatment Stage:
   • Artificial Grille: Removes large impurities (debris, fibers) to protect subsequent equipment.
   • Regulating Pond: Balances water quality and quantity, mitigating impact loads from peak discharge.
   • Hydrolysis Acidification Tank: Decomposes macromolecular organic matter (fats, proteins) into small molecules, improving biodegradability; reduces odor generation.
2. Biochemical Treatment Stage:
   • A/A/O Biochemical Pool: Divided into A-level (anoxic) and O-level (aerobic) pools.
     • A-level Pool: Facultative microorganisms convert organic nitrogen into ammonia nitrogen, and denitrify NO₂⁻-N/NO₃⁻-N into N₂, eliminating nitrogen eutrophication; dissolved oxygen (DO) ≈0.5mg/L.
     • O-level Pool: Autotrophic nitrifying bacteria convert ammonia nitrogen into nitrate nitrogen; DO ≥3mg/L, gas-water ratio 15:1. Elastic three-dimensional fillers (80% installation density) provide attachment sites for microorganisms.
3. Deep Separation Stage:
   • MBR Membrane Separation: Achieves efficient solid-liquid separation, retaining microorganisms and suspended solids; effluent TSS <5mg/L, ensuring RO system stability.
   • Reverse Osmosis (reverse osmosis): Further removes residual organic matter, salts, and micro-pollutants, producing high-quality reclaimed water meeting reuse standards.
4. Disinfection & Recycling Stage:
   • Chlorine Dioxide Disinfection: Inactivates pathogenic microorganisms (total coliforms <10 CFU/100mL) without toxic by-products.
   • Reclaimed Water Storage & Distribution: The treated water is stored in a clear water tank for reuse in toilet flushing, greening, and cleaning.

3.2 Core Technical Advantages

Technical Highlight	Description
Integrated Design	Combines pretreatment, biochemical treatment, membrane separation, and disinfection in one device; reduces footprint by 40% compared to split-type equipment.
Double Membrane Depth Treatment	MBR + RO combination ensures effluent quality; reuse rate reaches ≥80%, significantly saving freshwater resources.
Intelligent Control	PLC and SCADA system realize automatic start-stop, dosing adjustment, and membrane cleaning; liquid level controller links with pumps to adapt to flow fluctuations.
Sludge Reduction	MBR membrane retains high-concentration microorganisms, extending sludge age and reducing sludge production by 30-50% compared to traditional processes.
Odor Control	Hydrolysis acidification pre-treatment + aerobic decomposition minimizes anaerobic odor generation; closed equipment structure further reduces odor diffusion.

3.3 Key Supporting Systems

• Pre treatment filtration system: Grille + quartz sand/activated carbon filter ensures RO membrane inlet water quality.
• Chemical dosing system: PAM/PAC dosing device enhances flocculation effect, protecting MBR and RO membranes.
• Backwash System: Automatically backwashes filters and membranes to extend service life and maintain treatment efficiency.

4. Project Effectiveness Verification

4.1 Pollutant Removal Efficiency

Pollutant	Inlet Concentration	Effluent Concentration	Removal Rate
COD	<500 mg/L	<30 mg/L	≥94%
BOD₂₅	<300 mg/L	<5 mg/L	≥98%
TSS	<150 mg/L	<5 mg/L	≥97%
Fats and Oils	<10 mg/L	<0.5 mg/L	≥95%
Ammonia Nitrogen	<50 mg/L (estimated)	<1 mg/L	≥98%
Total Coliforms	10⁴-10⁶ CFU/100mL	<10 CFU/100mL	≥99.9%

4.2 Operational Performance

• Stability: Continuous operation for 7200 hours with stable effluent quality; adapts to ±40% flow fluctuations and ±30% COD concentration changes.
• Reuse Efficiency: Daily reclaimed water output ≥80m³, annual water saving ≥29,200m³ (based on 365 working days/year).
• Energy Consumption: Specific energy consumption ≤1.2 kW·h/m³, lower than similar systems (1.5-2.0 kW·h/m³).
• Maintenance Cycle: Routine maintenance once a month; MBR membrane service life 3-5 years; RO membrane service life 3-4 years.

4.3 Economic & Environmental Benefits

• Economic Benefits: Annual water fee savings ≥USD 5,840 (based on 1 USD/m³ freshwater price); reduced sewage discharge fees by 80%.
• Environmental Benefits: Reduced freshwater extraction and sewage discharge; annual reduction of COD emission by ≥175 kg; sludge reduction lowers secondary pollution risks.

5. Case Corresponding Product Quotation Description

5.1 Quotation Overview

Item	Description	Quantity	Total Amount (USD)
Core Equipment	Integrated wastewater treatment device (A/A/O + MBR + disinfection)	1 set	Included in total
Deep Treatment Equipment	Reverse osmosis (RO) machine (including high-pressure pump, membrane element, filter)	1 set	Included in total
Pretreatment & Auxiliary Equipment	Grille, lift pumps, Roots blower, liquid level controller, internal pipelines/valves	1 set	Included in total
Control System	PLC + SCADA automatic control system, full-specification electrical control box	1 set	Included in total
Total Equipment Quotation	–	–	57,650
36-Month Consumables Cost	Precision filter cartridges, chemicals, RO membrane elements, MBR membrane, quartz sand/activated carbon	–	23,527

5.2 Quotation Terms

Term Type	Details
Validity Period	30 working days from the date of quotation
Payment Terms	T/T: 40% deposit for production, 60% balance paid before shipment
Production & Delivery Cycle	30 days (from receipt of deposit to delivery)
Incoterms	EXW (includes international transportation standard packaging)
Warranty Period	12 months from the date of delivery (free repair/replacement for non-human damage under correct usage)
Installation & Maintenance	– Online: Free (provides manual, video guidance, and online engineer support) – On-site: USD 15,000 (includes visa, air tickets, accommodation, labor costs; requires local workers’ assistance)
Customization	Accepts customization based on actual water quality and reuse requirements (price and production time adjusted accordingly)

5.3 Additional Notes

• The system is designed for 380V/3P/50Hz power supply; customized power supply can be provided upon request.
• Spare parts (membranes, pumps, aeration devices) are provided at preferential prices for long-term supply.
• The regulating pond can be built by the customer or included in the equipment set based on site conditions.

6. Frequently Asked Questions (FAQ)

6.1 Installation & Commissioning

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

A: The system requires a flat installation surface (load-bearing ≥3 tons/m²) with space matching equipment dimensions (12m×2.4m×2.55m for integrated device + 3m×1m×2.2m for RO machine). It needs access to 380V AC power supply and stable wastewater inlet/drainage pipelines. We provide detailed installation drawings; online commissioning takes 3-5 days, while on-site commissioning (if purchased) takes 7-10 days.

6.2 Maintenance & Upkeep

Q: How often do MBR and RO membranes need to be replaced, and what is the cost?

A: The MBR membrane has a service life of 3-5 years, with a replacement cost of USD 40/m² (450m² total: USD 18,000). The RO membrane element has a service life of 3-4 years, with a replacement cost of USD 330/pc (3 pcs total: USD 990). Routine maintenance includes monthly cleaning of membranes and quarterly replacement of precision filter cartridges.

Q: What are the key points of daily maintenance?

A: Daily maintenance focuses on: 1) Checking pump and blower operation status; 2) Monitoring water quality indicators (COD, turbidity, conductivity) via the control system; 3) Replenishing chemicals (flocculants, disinfectants) in a timely manner; 4) Cleaning the grille to prevent clogging; 5) Conducting monthly backwashing of filters and membranes.

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 components (MBR membrane module, RO membrane pressure vessel, pump, blower, control system). Damage from improper operation, natural wear, or unauthorized modification is not covered.

Q: How to get after-sales technical support?

A: You can contact our after-sales team via the official email or phone. We respond to inquiries within 2 hours and provide remote technical guidance; for complex faults, on-site technicians can be dispatched (additional fees apply for non-warranty services). We also conduct 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, chemicals, and consumables. For a 100m³/day system, the monthly electricity cost is about USD 360 (based on 0.1USD/kW·h), chemical cost about USD 111 (36-month average), and consumable cost about USD 654 (36-month average), with a total monthly operating cost of ≈USD 1,125 (varies by local prices).

6.5 Safety & Compliance

Q: Is the reclaimed water safe for multiple reuse scenarios?

A: Yes. The reclaimed water meets GB/T 18920-2022 “Reclaimed Water for Urban Miscellaneous Use” standards: it is safe for toilet flushing, greening irrigation (non-edible crops), road cleaning, and landscape water supplementation. It does not contain harmful residues and complies with environmental and health requirements.

Q: How to handle system failures to avoid untreated wastewater discharge?

A: The system is equipped with an emergency overflow pipeline and regulating pond (accident storage function) to temporarily store untreated wastewater during failures. The PLC control system triggers real-time alarms for abnormal conditions (e.g., pump failure, membrane blockage), and our technical team provides emergency guidance to minimize downtime and environmental impact.