Brief Introduction to Industrial Reclaimed Water System Overview

An industrial reclaimed water system takes enterprise production wastewater, circulating blowdown water and comprehensive plant wastewater as raw water. After graded purification treatment, it produces reclaimed water with water quality between raw water and pure water. Its core goals are water conservation, emission reduction, and lower water intake and sewage discharge costs, with a water resource reuse rate reaching 85%~95%.

1. Core Process Flow

Influent → Pretreatment → Biochemical/Physicochemical Main Treatment → Membrane Advanced Treatment → Disinfection → Reclaimed Water Storage Tank → Production Reuse

2. Process Function Description

(1) Pretreatment Unit

Composed of mechanical bar screens, equalization tanks, coagulation sedimentation tanks and multimedia filters. It intercepts large particulate impurities, balances water quality and volume, removes suspended solids, colloids, floating oil and partial organic matter, eliminates impacts of fluctuating water quality and volume on downstream processes, and prevents membrane module clogging and fouling.

(2) Main Treatment Unit

Two mainstream processes are available:

① Physicochemical Process: Chemical dosing, flocculation and activated carbon adsorption. Applicable to wastewater with low COD and no nitrogen & phosphorus control requirements.

② Biochemical Process: A/O and MBR (Membrane Bioreactor). It efficiently degrades soluble pollutants including COD, ammonia nitrogen and total nitrogen, replaces traditional secondary sedimentation tanks, delivers excellent solid-liquid separation, generates less excess sludge, and fits most industrial wastewater scenarios.

(3) Advanced Treatment Unit

Centered on dual-membrane process of Ultrafiltration (UF) + Reverse Osmosis (RO). Ultrafiltration removes colloids, bacteria and macromolecular organic substances; reverse osmosis eliminates dissolved salts, heavy metals and trace organics, and precisely controls effluent conductivity to meet diverse water quality demands for circulating cooling water and precision production makeup water.

(4) Disinfection & Reuse Unit

Ultraviolet (UV) or ozone disinfection is adopted to kill aquatic microorganisms and restrain their reproduction. Treated reclaimed water is stored in dedicated storage tanks, then pressurized and conveyed to each water consumption point via pump sets to form a closed-loop water circulation system within the plant.

3. Process Selection Principles

Process selection shall be based on raw water quality, reuse standards, land occupation and operation & maintenance costs:

Low-standard reuse (cooling, flushing): Pretreatment + Physicochemical Treatment + Disinfection

Medium & high-standard reuse (process makeup water): Pretreatment + MBR + Dual-membrane Treatment + Disinfection

4. Core Advantages

Modular integrated design and easy operation & maintenance; stable water quality with strong shock resistance; drastically reduced municipal water intake and sewage discharge fees, complying with industrial water conservation and environmental compliance requirements.