Improving sewage sludge compost process and quality by carbon sources addition.

Area of Science:

• Environmental Science
• Microbiology
• Soil Science

Background:

• Sewage sludge (SS) composting requires careful management of carbon and nitrogen ratios.
• Optimizing carbon sources is crucial for efficient organic matter degradation and nutrient conversion.

Purpose of the Study:

• To evaluate the impact of different carbon sources on the sewage sludge composting process.
• To assess the effects on compost quality, nitrogen conversion, and maturity.

Main Methods:

• Lab-scale composting experiments were conducted in 5 L reactors over 32 days.
• Sewage sludge was amended with various carbon sources, including readily degradable ones like glucose and sucrose.
• Key parameters monitored included dissolved organic carbon, CO2 emission, dehydrogenase activity, nitrification, germination index, and ammonia (NH3) emission.

Main Results:

• Readily degradable carbon sources promoted organic matter degradation and accelerated compost maturation.
• Addition of glucose and sucrose increased dissolved organic carbon, CO2 emission, dehydrogenase activity, and nitrification.
• NH3 emissions were significantly reduced by 26.9% with glucose and 32.1% with sucrose.

Conclusions:

• Readily degradable carbon sources enhance microbial activity and nutrient assimilation during SS composting.
• These sources effectively improve compost quality, reduce ammonia volatilization, and accelerate maturation.
• Optimizing carbon source addition is a viable strategy for sustainable sewage sludge management.