[Mainland China] New Discharge Standard of Water Pollutants for the Textile Industry (GB 4287—2026) to Take Effect; Industrial Wastewater Regulation Shifts to "Characteristic Pollutants + Comprehensive Toxicity + Risk Control"

Introduction

Starting September 1, 2026, a batch of new water environment standards enters its implementation window, including the new Discharge Standard of Water Pollutants for the Textile Industry (GB 4287—2026) and the Technical Guideline for Formulating Water Pollutant Discharge Standards for Centralized Wastewater Treatment Facilities in Industrial Parks (HJ 945.4—2026). The new textile standard adds a zebrafish egg acute toxicity parameter, and the Ministry of Ecology and Environment (MEE) simultaneously issued the standard Water Quality—Determination of Acute Toxicity—Zebrafish Method (HJ 1455—2026). Industry analysts note that industrial wastewater regulation is shifting from meeting conventional indicators to characteristic pollutants + comprehensive toxicity + real risk control, with chemical, printing and dyeing, pharmaceutical, new materials, and coal chemical parks most affected.

I. Core Changes of the New Standard: Regulatory Upgrade from Conventional Indicators to Toxicity Screening

The core feature of this standard upgrade is the introduction of a biological toxicity assessment dimension alongside conventional indicators such as chemical oxygen demand (COD), ammonia nitrogen, total nitrogen (TN), and total phosphorus (TP).

Key changes in GB 4287—2026:

• New zebrafish egg acute toxicity parameter — biological toxicity assessment replaces some chemical indicators, more directly reflecting the real risk of wastewater to aquatic ecosystems.
• Strengthened control of characteristic pollutants — stricter discharge limits are set for characteristic pollutants unique to the dyeing and printing industry, such as refractory organics, heavy metals, and dye intermediates.
• Differentiated park-based control — HJ 945.4—2026 requires industrial parks to set discharge standards one park, one policy based on the types of enterprises and wastewater characteristics, ending the one-size-fits-all approach.

Technical support from HJ 1455—2026:

• It designates the zebrafish method as the standard method for determining acute toxicity in water quality, applicable to domestic sewage, industrial wastewater, and other water types.
• It provides parks and enterprises with a unified technical specification for toxicity screening, supporting regulatory enforcement and self-monitoring.

II. A Shift in Regulatory Paradigm: From After-the-Fact Remediation to Proactive Prevention

According to the MEE's policy interpretation on industrial wastewater pollution risk prevention, the regulatory gate is moving significantly upstream:

• Enterprise side — shifting from the after-the-fact remediation model of "exceedance → inspection → firefighting" to proactive prevention of "advance screening → pre-rectification → record keeping."
• Park side — shifting from the extensive model of "unified intake and unified treatment" to refined governance of "water quality identification, segregated treatment, toxicity screening, and risk response."
• Enforcement side — shifting from "checking conventional indicators" to "checking characteristic pollutants + comprehensive toxicity + risk control records."

This shift means that industrial park wastewater treatment is no longer just about building a plant that meets standards; it now requires:

• Water quality identification capability — the ability to identify the characteristic pollutant composition of wastewater discharged by different enterprises.
• Segregated treatment capability — applying differentiated treatment processes to different water qualities, avoiding a one-size-fits-all approach.
• Toxicity screening capability — establishing routine toxicity monitoring mechanisms to promptly detect abnormal discharges.
• Risk response capability — developing emergency plans and response procedures for sudden pollution incidents.

III. Industry Impact: Five Sectors Under Pressure, Technology Upgrade Imminent

The new standard has the most direct impact on the following five sectors:

• Chemical parks — with many types of high-concentration characteristic pollutants, they face the strictest requirements for segregated treatment and toxicity control.
• Printing and dyeing industry — dyes, auxiliaries, and sizing agents produce wastewater with high color and many refractory organics, making it a key target of zebrafish toxicity testing.
• Pharmaceutical industry — emerging contaminants such as antibiotics and hormones are now under regulatory scrutiny, requiring treatment process upgrades.
• New materials industry — emerging contaminants such as nanomaterials and functional chemicals lack mature treatment technologies.
• Coal chemical parks — high-salinity, high-COD, high-toxicity wastewater places higher demands on zero liquid discharge (ZLD) technology.

For centralized wastewater treatment facilities in parks, this means:

• Process upgrade — moving from conventional processes such as A²/O and oxidation ditches to a full-chain refined treatment system of pretreatment + biological treatment + advanced treatment + toxicity control.
• Enhanced monitoring — adding new monitoring methods such as online monitoring of characteristic pollutants and online toxicity early warning.
• Higher operating standards — operators need stronger technical and emergency response capabilities, with correspondingly higher operating costs.

IV. Compliance Pathways: How Enterprises Can Meet the New Standard's Challenges

Facing the regulatory upgrade, enterprises and parks can take action in the following areas:

• Source reduction — optimize production processes to reduce the generation of characteristic pollutants, lowering end-of-pipe treatment pressure from the source.
• Segregated collection — implement clean-dirty separation and segregated collection at the workshop level to avoid mixing different wastewaters and multiplying treatment difficulty.
• Process adaptation — select treatment processes suited to wastewater characteristics, such as advanced oxidation, membrane separation, and activated carbon adsorption for advanced treatment.
• Toxicity monitoring — establish a self-monitoring system and conduct regular zebrafish toxicity tests to detect exceedance risks in advance.
• Record keeping — improve operation ledgers and monitoring records to provide a basis for regulatory inspections and compliance proof.

V. Outlook: Industrial Wastewater Treatment Enters the Era of Precision Control

The implementation of GB 4287—2026 and HJ 945.4—2026 marks a new stage in China's industrial wastewater treatment, moving from concentration compliance to risk control. Going forward, three-dimensional control of conventional indicators + characteristic pollutants + comprehensive toxicity will become the norm, driving the industrial wastewater treatment industry toward higher technical standards and more refined management.

This article is compiled from MEE standard announcements, industry analysis reports, and publicly available information.

About TIANYI TECH Co., Ltd. (TIANYI LIMITED)

TIANYI TECH Co., Ltd. specializes in wastewater treatment and water reuse, and is committed to providing municipal and industrial customers with efficient, low-carbon, and sustainable water treatment solutions. The company's business spans wastewater treatment engineering design, water reuse system construction, membrane separation technology applications, and smart water operation services, helping customers achieve water resource recycling as well as energy-saving and emission-reduction goals.