Case Studies

The Challenge

A major caustic soda manufacturer in Dahej, Gujarat, was grappling with a growing environmental challenge—managing high volumes of sulphate-rich effluent generated during their production processes. These effluents posed compliance risks under India’s tightening wastewater discharge regulations, and traditional treatment methods failed to offer efficient sulphate separation or value recovery.

Given the scale of production and the critical need to achieve sustainability goals, the client required a solution that could recover usable materials, minimize waste, and align with Zero Liquid Discharge (ZLD) protocols.

The Solution

Geist designed and implemented India’s first Sodium Sulphate Recovery System tailored specifically for the caustic soda industry. The customized solution integrated:

• Advanced Crystallization Techniques to selectively recover high-purity sodium sulphate.

• Solid-Liquid Separation Technologies for enhanced system efficiency.

• ZLD Integration to eliminate liquid waste discharge and ensure regulatory compliance.

The system was developed to fit into the client’s existing infrastructure, minimizing civil work while maximizing process recovery and operational uptime.

Process Overview

The system includes a multi-stage treatment line involving:

• Pre-conditioning of the sulphate-rich effluent stream

• Controlled crystallization to induce selective sodium sulphate precipitation

• Centrifuge-based separation of high-purity crystals

• Filtrate recovery and recycling to upstream processes

• Final brine concentration integrated into the client’s ZLD architecture

The entire operation is automated with real-time monitoring of sulphate concentrations, temperature, and purity metrics, ensuring stable output quality.