KRBL Limited
The Challenge
Ageing ETP Failing Under Peak Production Loads
KRBL Limited is India's largest basmati rice company and one of the world's leading rice exporters, with iconic brands including India Gate, Unity, and Nur Jahan. Operating state-of-the-art rice milling and processing facilities in Ghaziabad (Uttar Pradesh), Dhuri (Punjab), and Gautam Budh Nagar, KRBL processes over 1 million tons of rice annually for domestic and international markets across 90+ countries.
The company's rice milling, parboiling, and packaging operations generate substantial process wastewater from paddy washing, equipment cleaning, and utility systems. The existing ETP at their Ghaziabad facility used outdated trickling filter technology that was underperforming and struggling to meet Environmental Protection Act, 1986 discharge standards during peak production at 650 m³/day (BOD: 1,300 mg/L, COD: 3,000 mg/L). A comprehensive upgrade was required — but it had to be executed without disrupting continuous rice processing operations.
Key Issues:
- !Existing trickling filter technology underperforming and unable to consistently meet discharge standards during peak production
- !Zero-downtime requirement — any production shutdown would result in significant financial losses and impact international supply commitments
- !KRBL had substantial capital invested in existing civil structures that needed to be retrofitted rather than demolished
- !Water reuse pathway required — treated water needed to meet quality suitable for non-potable reuse applications
- !Investment budget of approximately ₹85 lakhs required maximum performance improvement with superior ROI
The Solution
Trickling Filter Converted to High-Performance Two-Stage MBBR System
Rather than proposing complete replacement, Spans Envirotech conducted a thorough assessment of existing infrastructure, wastewater characteristics, and operational patterns. We identified that the core civil structures were sound and could be repurposed, but the treatment process configuration needed fundamental transformation. Our strategy: convert the outdated single-stage trickling filter system into a high-performance two-stage aerobic biological treatment (2AB) system optimised for rice processing wastewater.
The most innovative aspect was transforming the existing trickling filter into a modern Moving Bed Biofilm Reactor (MBBR) and high-rate aeration tank — removing trickling filter media, installing high-efficiency diffused aeration systems (1,100–1,200 m³/hr capacity), and configuring the reactor to operate at high MLSS (6,000–8,000 mg/L). The retrofit was executed in carefully planned phases to ensure KRBL maintained wastewater treatment capability throughout the upgrade, with no impact on rice processing operations.
Technologies Deployed:
Implementation Timeline:
Phase 1: Audit & Redesign Strategy
Conducted a thorough assessment of existing infrastructure, wastewater characteristics, and operational patterns. Identified that core civil structures were sound and could be repurposed. Developed a phased retrofit plan to enable continuous operation throughout the upgrade.
Phase 2: Stage 2 Upgrade (Existing Aeration Tank)
Installed new equipment and enhanced aeration capacity (600 m³/hr) in the existing aeration tank while the original system continued operating. Gradually shifted treatment load to the upgraded Stage 2 reactor.
Phase 3: Stage 1 Conversion (Trickling Filter to MBBR)
Executed trickling filter conversion during a planned maintenance window — removing old media, installing high-efficiency diffused aeration systems (1,100–1,200 m³/hr), and configuring for high-MLSS bio-sorption mode at limiting dissolved oxygen.
Phase 4: Commissioning & Optimisation
Commissioned integrated two-stage system and optimised performance through controlled startup and biological acclimation. Conducted full-load performance testing across all parameters. Total project completed in 6 months with zero production downtime.
The Results
95%+ Removal, ₹1+ Crore Saved, Zero Downtime
95%+
COD Removal
COD reduced from 3,000 mg/L to <150 mg/L — consistently meeting EPA 1986 Schedule VI standards
98%+
BOD Removal
BOD reduced from 1,300 mg/L to <25 mg/L, well below the 30 mg/L discharge limit
₹1+ Cr
Infrastructure Saved
Existing tanks, clarifiers, and civil structures salvaged through creative retrofitting
₹85 Lakhs
Total Investment
Delivered versus potential ₹2+ Crore for new construction — a fraction of the cost
Zero
Production Downtime
100% operational continuity maintained throughout the 6-month upgrade period
100%
Compliance
Zero regulatory violations since commissioning, including during peak harvest season
“Spans Envirotech delivered what other vendors said was impossible — a complete ETP transformation without stopping our rice milling operations. Their creative conversion of our trickling filter into a high-performance MBBR system was brilliant engineering. We salvaged over ₹1 Crore in existing civil works, completed the project in half the time, and achieved 95%+ COD removal. Most impressively, they executed the entire retrofit without a single hour of production downtime. Spans proved that smart retrofitting beats new construction when you have the right engineering partner.”
Manoj Kumar
Engineering Manager, KRBL Limited, Ghaziabad
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