[Chinese Mainland] The Concept of "Segregated Collection and Segregated Treatment" for Park Wastewater Gains Traction: Front-End Identification of Water Quality Differences, Source Pretreatment and Reuse

Introduction

"Segregated Collection and Segregated Treatment" is becoming the mainstream concept for Industrial Wastewater treatment in Industrial Parks. Its core is to collect wastewater by water quality differences at the front end of the pipe network, implement segregated treatment and cascade reuse for high-salinity, highly refractory, and low-concentration clean drainage, and resolve complex pollution risks by moving them forward. The growing popularity of this approach reflects a paradigm shift in Industrial Park water management from "mixing and dilution, end-of-pipe兜底" to "source classification, process reuse."

Background

Traditional parks mostly adopt a "single-pipe collection, mixed treatment" model. After wastewater from different enterprises and different process sections is mixed, water quality fluctuates sharply, which not only increases the difficulty of end-of-pipe treatment and the consumption of chemicals and electricity, but also makes clean Reclaimed Water that could have been reused difficult to utilize because it is diluted by polluted water. As water intake constraints tighten and discharge standards become stricter, both the economics and compliance of mixed treatment are under pressure, and "how to separate and how to reuse" has become a core issue for park operators.

Core

The implementation of "Segregated Collection and Segregated Treatment" includes three levels of action: first, tiered pipe networks—separate collection systems are set up for clean drainage, general production wastewater, and high-salinity/high-toxicity characteristic wastewater to avoid "good water being contaminated by bad water"; second, source pretreatment—desalination, oil removal, and removal of characteristic pollutants are completed at pollution-generating nodes to reduce the load on centralized facilities; third, cascade reuse—clean Reclaimed Water is directly reused for cooling and washing, while concentrate enters specialized Zero Liquid Discharge / ZLD or salt separation units. Front-end classification makes it possible to "reuse what should be reused and finely treat what should be treated."