The functional membrane is conducive to improve green waste composting process related microenvironment

Area of Science:

• Environmental Science
• Biotechnology
• Waste Management

Background:

• Aerobic composting of green waste (GW) is sustainable but faces challenges like slow processing, low efficiency, nitrogen loss, and poor quality.
• Conventional methods often fail to optimize the composting microenvironment for efficient bioconversion.

Purpose of the Study:

• To investigate the impact of functional membranes with varying air and moisture permeability on the green waste composting microenvironment.
• To assess the effects of these membranes on composting efficiency, product quality, and economic viability.

Main Methods:

• Three functional membrane treatments (T1-T3) and an uncovered control (CK) were employed.
• Key parameters monitored included temperature, moisture, nitrogen content, organic matter degradation, enzyme activity, and compost maturity.
• A membership function model was used for comprehensive evaluation (compost product index - CEI).

Main Results:

• The T2 membrane treatment achieved a maximum temperature of 66.4°C and an extended thermophilic phase of 12 days.
• T2 significantly improved moisture content (+29.3%), nitrogen forms (+36.3% ammonium, +63.0% nitrate), organic matter degradation (+15.9%), and humic substances (+8.3% humic acid, +11.1% fulvic acid) compared to CK.
• Composting maturity was reduced to 26 days, with a CEI of 0.88 for T2, and composting costs decreased by 18.6%.

Conclusions:

• Optimal membrane configuration creates a favorable microenvironment by regulating gas-liquid exchange, enhancing composting performance.
• Membrane-assisted composting improves nitrogen retention, accelerates organic matter transformation, and yields higher quality compost.
• This approach offers an efficient and cost-effective solution for green waste management.