Biodegradable organic matter and rapid-rate biofilter performance: A review

Area of Science:

• Environmental Science
• Water Treatment Engineering
• Organic Chemistry

Background:

• Biodegradable organic matter (BOM) is prevalent in surface waters and presents challenges for drinking water treatment.
• BOM can cause bio-regrowth in distribution systems, form disinfection by-products, and include specific compounds of concern.

Purpose of the Study:

• To critically review the occurrence and oxidant effects on BOM.
• To evaluate the performance of rapid-rate biofiltration in removing BOM.
• To analyze the impact of preozonation, oxidant backwashing, empty bed contact time (EBCT), and temperature on biofiltration.

Main Methods:

• Literature data analysis of 100 studies on non-ozonated water and 103 studies on ozonated water.
• Analysis of 117 biofilter operation conditions.
• Quantification of total organic carbon (TOC), biodegradable organic carbon (BDOC), and assimilable organic carbon (AOC).

Main Results:

• Non-ozonated water contained a median of 20% BDOC and 3% AOC.
• Ozonated water showed increased median values of 30% BDOC and 9% AOC.
• Biofilters with an average EBCT of 12 minutes removed a median of 12% of influent TOC.
• Higher TOC removal (15% median) was observed for ozonated waters compared to non-ozonated waters (10% median).
• Increasing temperature from ≤10°C to ≥20°C enhanced TOC removal from 10% to 17% (median).

Conclusions:

• Biofiltration is an efficient technology for removing a portion of BOM from drinking water influent.
• Optimizing biofiltration processes, including preozonation and temperature control, can maximize BOM removal.
• Understanding BOM characteristics and biofiltration performance is crucial for effective water treatment strategies.