Techno-economic feasibilty analysis of Zero Liquid Discharge (ZLD): a case study approach
Student name: Ms Rashmi Komal and Ms Snigdha Basu Ray
Guide: Dr Kamna Sachdeva
Year of completion: 2015
Host Organisation: ETI Dynamics, New Delhi
Supervisor (Host Organisation): Ms Garima Dhar
Abstract: Pollution due to industrial effluent has always been a major problem daunting India and has recently been in prime focus because of the intimidating plight of the rivers. Non-compliance of discharge standards and inefficient resource usage by industries ultimately necessitates to work towards Zero Liquid Discharge (ZLD) systems. This study endeavors to sketch the probable discharge scenarios of grossly polluting industries and proposes possible zero liquid and sludge discharge schemes using a case study approach. The study reveals that most of the industries are polluting the rivers and groundwater. Conventional treatment technologies are no longer sufficient in treating effluents. Further, the shortage of water and energy worsens the situation. Adopting better treatment options in industries is imperative to make them self-sustainable and environment friendly. The prominent industrial sectors like Distilleries, Pulp & Paper, Textile, Tanneries and Pharmaceuticals need special emphasis for enforcement of ZLD. Zero Liquid Discharge is recognized and certified based on two criteria which are, water consumption versus wastewater reused and corresponding solids recovered. The study emphasizes on the technology prerequisites and technical and economic feasibility analysis for achieving ZLD. Although the route to achieve ZLD leads to exorbitant financial burden on industries but resource recovery, reduced compliance pressure and improved public image makes it an attractive option for industries. Moreover, industries should use their technical expertise and astuteness to adopt the best viable option-economically and technically, available to achieve ZLD.
Keywords: Wastewater characteristics, Reverse Osmosis, Multiple Effect Evaporators, Sludge, SWOT
