Ecotoxicological evaluation of pig slurry

Area of Science:

• Environmental Science
• Ecotoxicology
• Analytical Chemistry

Background:

• Swine sewage is a potential source of environmental contaminants.
• Nutrients and pollutants in wastewater can pose ecological risks.
• Farm wastewater treatment systems require rigorous environmental risk assessment.

Purpose of the Study:

• To estimate the environmental risk of swine wastewater from various farm treatment systems.
• To identify key contributors to toxicity, including copper (Cu), zinc (Zn), and ammonia (NH3).
• To quantify organic compounds using advanced extraction techniques.

Main Methods:

• Acute toxicity testing using Daphnia magna.
• Assessment of Cu, Zn, and ammonia concentrations.
• Quantification of organic compounds via Solid Phase Microextraction (SPME) devices, Solid Phase Extraction (SPE), and solvent extraction.
• Exhaustive extraction for indole, phenol, Polychlorinated Biphenyls (PCBs), and fatty acids.

Main Results:

• Ammonia (NH3) and copper (Cu) were identified as primary contributors to toxicity, with LC50 values observed at 1-5% dilution.
• Advanced extraction methods yielded significantly higher recoveries of indole and phenol.
• Quantification revealed PCB levels at 430 ppb and fatty acids at approximately 150 ppm.

Conclusions:

• Swine wastewater poses a significant ecotoxicological risk, primarily driven by ammonia and copper.
• Comprehensive extraction methods are crucial for accurately assessing the full spectrum of organic pollutants, including PCBs and fatty acids.
• Effective management and treatment of swine wastewater are essential to mitigate environmental impacts.