What Is ZLD System?

Zero Liquid Discharge (ZLD) explained in simple terms — meaning, process flow, cost and compliance requirements.

Meaning of Zero Liquid Discharge (ZLD)

Zero Liquid Discharge (ZLD) is a wastewater treatment approach where no liquid effluent is discharged outside the plant boundary. All wastewater is treated, recycled, and reused, leaving behind only solid waste.

ZLD System Process Flow

Pre-Treatment

ETP / STP treatment to reduce COD, BOD and TSS

Membrane System

RO, UF or NF to recover maximum reusable water

Evaporation

MEE / ATFD for handling RO reject

ZLD System Cost in India

  • ✔ Small industries: ₹1 – ₹3 Crore
  • ✔ Medium industries: ₹3 – ₹8 Crore
  • ✔ Large industries: ₹10 Crore+
  • ✔ High power & O&M cost compared to ETP

Why CPCB Mandates ZLD

Water Conservation

Maximum reuse of treated wastewater

Pollution Control

Prevents discharge into rivers and drains

Regulatory Compliance

Mandatory for many industrial sectors

Suggested Blogs

CPCB Guidelines for STP & ETP

Understand regulatory requirements.

ETP Plant Cost in India

Cost factors before implementing ZLD.

MBBR vs SBR vs MBR

Technology comparison for pre-treatment.

Planning a ZLD System?

A2Z Enviro Services designs ZLD systems with optimized recovery, lower operating cost and full CPCB compliance.

Consult ZLD Experts
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