Adding a recyclable amendment to facilitate sewage sludge biodrying and reduce costs

Area of Science:

• Environmental Engineering
• Waste Management
• Biotechnology

Background:

• Industrial-scale biodrying requires economical and consistently available amendments.
• Sewage sludge treatment presents challenges in moisture reduction and cost-effectiveness.

Purpose of the Study:

• To develop and evaluate a novel recyclable biodrying amendment (RBA) for sewage sludge.
• To assess the impact of RBA on biodrying performance, microbial activity, and product quality.

Main Methods:

• Pilot-scale biodrying trials comparing RBA with sawdust (T_R) against sawdust alone (T_C).
• Monitoring of pile temperature, thermophilic phase duration, moisture content, and heat use efficiency.
• Analysis of enzyme activities (α-amylase, cellulase, etc.) and organic matter composition (FTIR, humic/fulvic acids).

Main Results:

• RBA addition led to higher pile temperatures and extended thermophilic phases compared to the control.
• Final moisture content was below 50% in both treatments with comparable heat use efficiency.
• RBA enhanced biodegradability of lipids, proteins, and polysaccharides, and promoted humification.
• Enzyme activity patterns indicated effective organic matter breakdown during thermophilic phase.
• RBA demonstrated a high recovery rate (95.6%) for reuse.

Conclusions:

• The recyclable biodrying amendment (RBA) is effective for sewage sludge treatment, improving process efficiency.
• RBA reduces amendment costs and results in a biodrying product suitable for incineration without energy deficit.
• The RBA's recyclability and performance support its industrial application in sustainable waste management.