I. Process Design

Process Flow

1.1 Pre-treatment

• Screen Filtration: Use sand filters to remove suspended solids and sand particles.
• Salting Out: Pre-treat with a salt bath (e.g., NaCl solution) to reduce the osmotic pressure of water and improve the quality of RO membrane effluent.
• UV Disinfection: Disinfect the pre-treated water with ultraviolet (UV) irradiation.

1.2 Reverse Osmosis

• RO Membrane Operation: Use RO membranes to remove the majority of salts and other impurities.

1.3 Pure Water Collection

• Collection of High-Purity RO Water: Collect the high-purity RO water and disinfect it (e.g., with UV or chlorination).

1.4 Reuse Treatment

• Further Treatment of Reused Brine: Treat the reused high-salinity water (e.g., neutralization, precipitation, or distillation) to meet the water quality requirements for reuse.

Detailed Process Steps

2.1 Pre-treatment

• Sand Filters: Remove suspended solids and sand particles.
• Salting Out: Pre-treat with NaCl solution, maintaining a salt concentration of 1:20 (NaCl:water).
• UV Disinfection: Disinfect the pre-treated water using UV lamps.

2.2 Reverse Osmosis

• High-Performance RO Membrane: Use high-performance RO membranes to remove the majority of salts and impurities.

2.3 Pure Water Collection

• Collector for RO Water: Collect RO water via a collector and disinfect it with UV or chlorination.

2.4 Reuse Treatment

• Neutralizer: Neutralize acidic or alkaline substances in RO water.
• Precipitation Filter: Perform precipitation treatment on the reused high-salinity water to remove suspended solids.
• Distilled Water Recovery: Distill the reused high-salinity water to collect high-purity water.

II. List of Required Materials

Equipment

1.1 RO Membrane

• High-Flux RO Membrane: (e.g., with a permeability of 100,000 and an area of 0.5–1 m²).
• RO Components: (including membrane housing and support structure).

1.2 Pre-treatment Equipment

• Sand Filters: (for filtering sand and suspended solids).
• Salting Out Equipment: (salt bath device with NaCl solution concentration of 1:20).

1.3 Pure Water Collection Equipment

• UV Disinfection Equipment: (UV lamps).
• Collector: (container for collecting high-purity water).

1.4 Reuse Treatment Equipment

• Neutralizer: (for neutralizing reused RO water).
• Precipitation Filter: (for precipitating reused high-salinity water). Distillation system (for further purification of reused water).

1.5 Auxiliary Equipment

• Acid Cleaning Equipment: (for cleaning RO membranes).
• Scale Removal Brushes, Filter Nets, Acid-Base Balancers, etc.

1.6 Other Equipment

• Piping and Connectors: (for water circulation and equipment connection).
• Control System: (e.g., PLC to control RO operation).

Materials

2.1 RO Membrane

• High-Flux RO Membrane: (e.g., with a permeability of 100,000 and an area of 0.5–1 m²).
• Removable or Fixed Membrane Housing.

2.2 Salts

• NaCl Solution: (concentration of 1:20).

2.3 Disinfectants

• UV Lamps or UV Disinfectants.

2.4 Acid Cleaning Scale Remover

• Acidic Solution: (e.g., HCl) for cleaning RO membranes.

2.5 Other Materials

• Sand Filter Material: (e.g., glass sand).
• UV Disinfection Lamps or UV Irradiation Equipment. Neutralizers, precipitants, etc.

III. Quality Requirements

1. RO Membrane: Complies with relevnt standards (e.g., ISO71271). PDI (permeability) meets design requirements.
2. Pre-treatment Equipment: Sand filter efficiency ≥95%. Salt addition in salting out equipment meets design requirements.
3. Pure Water Collection Equipment: UV disinfection equipment complies with safety standards. Collector capacity meets return water demand.
4. Reuse Treatment Equipment: Neutralizer and precipitation filter treatment capacity meets reuse demand. Distillation system has recovery capability.

Notes

1. High-Salinity Water Treatment: Consider the salt removal efficiency and return water treatment capacity when treating high-salinity water to prevent residual salts from affecting the RO membrane.
2. RO Membrane Selection: Choose the appropriate type of RO membrane based on water quality and effluent requirements.
3. Reuse Treatment: The reused high-salinity water must be treated (e.g., neutralized, precipitated, or distilled) to meet the water quality requirements for reuse.
4. Equipment Maintenance: Regularly clean the RO membrane and reuse treatment equipment to ensure the long-term stable operation of the system. The above design can be adjusted according to specific needs to ensure the efficient utilization of high-salinity groundwater and the stable operation of the RO membrane system.