Particle removal in a novel sequential mechanical filter system loaded with blackwater

Area of Science:

• Environmental Engineering
• Wastewater Treatment Technologies
• Sustainable Materials

Background:

• Onsite wastewater treatment systems often face challenges with high-strength influents.
• Traditional primary treatment methods may require significant space or energy.
• There is a need for efficient and cost-effective primary treatment solutions for decentralized wastewater management.

Purpose of the Study:

• To develop and evaluate a novel sequential mechanical filter system for primary onsite wastewater treatment.
• To assess the system's performance in removing key pollutants from blackwater.
• To determine the suitability of the system for high-strength wastewater streams.

Main Methods:

• A sequential mechanical filter system combining screening and a counter-flow wood-shavings filter was designed.
• The system was tested using blackwater from a student dormitory under batch loading conditions simulating high-frequency toilet flushing.
• Performance was evaluated based on the removal of suspended solids, chemical oxygen demand (COD), and total phosphorus (P).

Main Results:

• The filter system achieved high removal efficiencies: 78-85% for suspended solids, 60-80% for COD, and 42-57% for total phosphorus.
• The retentate produced had a dry matter content ranging from 13-20%.
• Higher removal performance was observed with increased inlet concentrations, indicating suitability for high-strength wastewater.

Conclusions:

• The novel sequential mechanical filter system presents a viable alternative for primary onsite wastewater treatment.
• The system demonstrates effective removal of pollutants from blackwater, particularly in high-concentration scenarios.
• Wood-shavings as a biodegradable matrix offer a sustainable approach to wastewater filtration.