Study of oyster shell as a potential substrate for constructed wetlands

Area of Science:

• Environmental Engineering
• Water Treatment Technologies
• Waste Management

Background:

• Swine wastewater poses environmental challenges due to high phosphorus content.
• Constructed wetlands (CWs) are a viable treatment option for wastewater.
• Oyster shell (OS) is an abundant waste material with potential for phosphorus adsorption.

Purpose of the Study:

• To evaluate the efficacy of oyster shell (OS) as a substrate for phosphorus removal in constructed wetlands (CWs).
• To investigate the mechanisms and distribution of phosphorus removal within the OS substrate in a vertical subsurface flow (VSSF) system.

Main Methods:

• Utilized vertical subsurface flow constructed wetlands (VSSFs) filled with oyster shell (OS) to treat swine wastewater.
• Analyzed phosphorus removal efficiency and distribution within the substrate layers.
• Identified the predominant forms of phosphorus in the system.

Main Results:

• Significant phosphorus removal was achieved in the OS-filled VSSF CWs.
• Oyster shell adsorption and precipitation were the primary mechanisms for phosphorus removal.
• Calcium phosphate (Ca-P) was identified as the dominant phosphorus form.
• Phosphorus distribution correlated with the vertical flow of wastewater through the substrate.

Conclusions:

• Oyster shell (OS) is a suitable and effective substrate for phosphorus removal in constructed wetlands (CWs).
• The use of OS in CWs offers a sustainable approach by reusing waste material.
• This method contributes to more environmentally friendly wastewater treatment systems.