Secondary wastewater disposal for crop irrigation with minimal risks

Area of Science:

• Environmental Science
• Microbiology
• Agricultural Engineering

Background:

• Wastewater reuse is crucial for water security and minimizing environmental risks.
• Assessing microbial and pathogen reduction in soil-plant systems is vital for safe water reuse.
• Irrigation methods influence the fate of microorganisms in reclaimed wastewater.

Purpose of the Study:

• To investigate the survival of fecal coliforms, coliphages (F+ and CN13), and helminth eggs in reclaimed wastewater applied to a vineyard.
• To compare the efficacy of on-surface and subsurface drip irrigation systems in reducing microbial load.
• To evaluate the impact of wastewater reuse on soil and potential health hazards.

Main Methods:

• Collection and analysis of wastewater from a stabilization pond.
• Sampling and testing of soil from a vineyard orchard.
• Application of reclaimed wastewater using on-surface and subsurface drip irrigation.
• Microbiological analysis to quantify fecal coliforms, coliphages, and helminth eggs.

Main Results:

• A significant decrease in microorganisms was observed in both irrigation systems.
• Subsurface drip irrigation demonstrated superior performance in reducing microbial counts compared to on-surface drip.
• Wastewater application resulted in a considerable reduction of fecal coliforms, coliphages, and helminth eggs in the soil.

Conclusions:

• Reclaimed wastewater irrigation can effectively reduce microbial contamination in vineyard soils.
• Subsurface drip irrigation is a more effective method for pathogen reduction in wastewater reuse applications.
• Further studies are needed to fully understand organism decay rates under various conditions for safe water reuse.