Water Treatment Solutions for Municipal, Industrial, and Marine

Water filtration plays a critical role in various industries, from municipal drinking water purification to seawater desalination and ballast water treatment for ships. Each application requires specialized filtration processes to meet specific quality standards and ensure environmental and public health safety. Below are detailed filtration processes for some of the most important water treatment applications.

1. Municipal Drinking Water Treatment

Application: Purification of surface or groundwater for residential and public use.

Core Goals: Removal of suspended solids (SS ≤ 1 NTU), microorganisms (bacteria, viruses), and heavy metals (such as arsenic and lead).

Filtration Products and Process:

Pre-treatment:

1. Multimedia Filters (Quartz Sand + Manganese Sand): Removes suspended solids (>50 µm) and iron/manganese ions (concentration ≤ 0.3 mg/L).

2. Activated Carbon Filters: Adsorbs organic matter (TOC ≤ 2 mg/L) and residual chlorine (≤ 0.5 mg/L).

Core Filtration:

1. Ultrafiltration Membranes (UF): Pore size 0.01–0.1 µm, removes bacteria and colloidal particles with a flux rate ≥ 50 LMH.

2. Reverse Osmosis (RO): Optional for high Total Dissolved Solids (TDS) water sources (>500 ppm), desalination rate ≥98%.

Disinfection:

1. Ultraviolet (UV) Sterilization: Wavelength of 254 nm, dose ≥ 40 mJ/cm², inactivates 99.99% of microorganisms.

2. Ozone Generator (Optional): Degrades organic micropollutants (e.g., pesticide residues).

Filtration Process:

1. Raw water → Screening → Multimedia filtration → Activated carbon adsorption → Ultrafiltration → UV disinfection → Water distribution network.

Compliance: Meets China's Drinking Water Health Standards (GB 5749-2022).

2. Seawater Desalination

Application: Supply of freshwater in coastal areas for industrial and residential use, as well as for islands.

Core Goals: Removal of salt (TDS ≤ 500 ppm), microorganisms, and boron (concentration ≤ 0.5 mg/L).

Filtration Products and Process:

Pre-treatment:

1. Self-cleaning Filters (316L Stainless Steel): Traps particles >100 µm (such as algae and larvae).

2. Ultrafiltration (UF): SDI ≤ 3 to prevent fouling of RO membranes.

Core Desalination:

1. Reverse Osmosis Membranes (RO, e.g., DOW SW30HR): Desalination rate ≥99.7%, operating pressure 5.5–6.5 MPa.

Post-treatment:

1. Boron Selective Resins: Adsorb boron to ≤ 0.5 mg/L.

2. Ultraviolet (UV) Sterilization: Inactivates residual microorganisms.

Filtration Process:

1. Seawater → Self-cleaning filtration → Ultrafiltration → RO desalination → Boron adsorption → UV disinfection → Freshwater storage tank.

Technical Challenge: High energy consumption (3–4 kWh/m³), reduced to 1.5–2 kWh/m³ with Energy Recovery Devices (ERD).

3. Ballast Water Treatment Systems (BWTS)

Application: Biological purification of ballast water from ships before discharge to prevent invasive species.

Core Goals: Inactivation of microorganisms (≤50 µm biological survival rate <10%), removal of suspended solids (≤50 µm).

Filtration Products and Process:

Physical Filtration:

1. Self-cleaning Filters (50 µm): Traps plankton and particles, handling flow rates ≥ 3000 m³/h.

Sterilization:

1. Ultraviolet (UV) Sterilization: High-intensity UVC (254 nm), dose ≥100 mJ/cm² to inactivate microorganisms.

2. Electro-chlorination System: Generates sodium hypochlorite (1–2 ppm) and neutralizes residual chlorine to ≤ 0.1 ppm.

Neutralization and Monitoring:

1. Activated Carbon Filters: Adsorb residual chlorine and organic compounds.

2. Online Sensors: Real-time monitoring of total suspended solids (TSS) and microorganism concentrations.

Filtration Process:

1. Ballast water → Self-cleaning filtration → UV disinfection → Electro-chlorination → Neutralization → Activated carbon adsorption → Discharge compliant with IMO's Ballast Water Management Convention (D-2 standard).

4. Wastewater Treatment (Municipal/Industrial)

Application: Treatment and reuse of municipal and industrial wastewater, including nutrient removal (nitrogen and phosphorus).

Core Goals: COD ≤ 50 mg/L, Suspended solids ≤ 10 mg/L, Nitrogen (TN ≤ 15 mg/L), Phosphorus (TP ≤ 0.5 mg/L).

Filtration Products and Process:

Pre-treatment:

1. Screening / Hydrocyclone Separators: Remove >5 mm debris (e.g., plastic, fibers).

Biological Treatment:

1. Activated Sludge Process: Degrades organic matter, combined with Membrane Bioreactor (MBR) membranes (pore size 0.04 µm) for solid-liquid separation.

Advanced Filtration:

1. Sand Filters: Remove suspended solids (SS ≤ 5 mg/L).

2. Reverse Osmosis (RO): Used for industrial water reuse, ensuring conductivity ≤ 100 µS/cm.

Disinfection:

1. Ozone/Chlorine Disinfection: Inactivates pathogens, with E. coli ≤ 1000 CFU/L.

Filtration Process:

1. Wastewater → Screening → Sedimentation → Activated sludge → MBR filtration → Sand filtration → RO → Ozone disinfection → Reuse/Discharge.

Innovation: Anammox process for anaerobic ammonia oxidation reduces nitrogen removal energy consumption by 30%.