Parameters affecting greywater quality and its safety for reuse
Adi Maimon1, Eran Friedler2, Amit Gross1
1Albert Katz International School for Desert Studies, Department of Environmental Hydrology and Microbiology, Zuckerberg Institute for Water Research, The Jacob Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, Sede Boqer Campus, 84990, Israel.
The Science of the Total Environment
|April 23, 2014
Summary
Safe greywater (GW) reuse for irrigation hinges on effective treatment systems. Inadequately treated GW poses health risks, while professionally treated water meets acceptable safety standards, highlighting the need for robust risk assessment and regulation.
Area of Science:
- Environmental Science
- Public Health
- Microbiology
Background:
- Greywater (GW) reuse for on-site irrigation is increasing globally.
- Potential health and environmental risks are associated with GW reuse.
- Understanding these risks and influencing factors is crucial for safe implementation.
Purpose of the Study:
- To assess the health risks of on-site greywater reuse.
- To identify key factors influencing these risks.
- To evaluate the microbial quality of treated greywater.
Main Methods:
- Analysis of physicochemical parameters and microbial load (E. coli, P. aeruginosa, S. aureus) in GW from 34 Israeli households.
- Household questionnaires on GW sources, treatment, and usage.
- Quantitative Microbial Risk Assessment (QMRA) integrating microbial data and exposure scenarios.
Main Results:
- Treatment type significantly impacts treated GW quality.
- Professionally treated GW (excluding kitchen effluent) showed acceptable E. coli levels and risk across exposure scenarios.
- Inadequately treated GW presented risks exceeding WHO guidelines.
Conclusions:
- Effective and well-designed treatment systems are essential for safe greywater reuse.
- A risk-assessment approach is recommended for refining regulations and evaluating GW treatment systems.
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