Analysing recycled water for reuse-challenges and solutions

Introduction

As the demand for freshwater rises and water scarcity becomes an increasingly pressing issue, the recycling of water for reuse has gained significant attention as a sustainable solution. However, the analysis of recycled water presents various challenges that must be addressed to ensure its safety and suitability for different purposes. This blog examines the challenges associated with analyzing recycled water for reuse and explores potential solutions to overcome these hurdles. By addressing these challenges effectively, we can enhance the reliability and acceptance of recycled water as a valuable resource in water management strategies.

https://ase.aseglobal.com/esg/water-reclamation/

Challenges and solutions

The presence of various contaminants in recycled water necessitates robust treatment processes to ensure its safe and effective reuse. Here's a closer look at the challenges associated with removing these contaminants:

Microbiological Contaminants:

Types: Bacteria (e.g., E. coli), viruses (e.g., rotavirus), protozoa (e.g., Giardia lamblia), and helminths (worms).
Health Risks: Can cause gastrointestinal illnesses, skin infections, and respiratory problems.
Analysis: Microbiological analysis typically involves culturing the water sample on specific media to identify and quantify viable microorganisms. Additionally, molecular techniques like PCR (polymerase chain reaction) can detect specific pathogens.
Emerging Concerns: Antibiotic-resistant bacteria pose a growing concern.

Chemical Contaminants:

Dissolved Organic Matter (DOM): Naturally occurring organic material from decaying plants and animals. Can promote microbial growth and disinfection byproduct formation.
Pharmaceuticals and Personal Care Products (PPCPs): Residuals of medications and personal care products like antibiotics, hormones, and disinfectants. Can have ecological and human health impacts.
Industrial Chemicals: Depending on the source of wastewater, industrial chemicals like solvents, pesticides, and heavy metals can be present.

Analysis: A wide range of analytical techniques are used depending on the specific chemical of concern. These can include:

Chromatography: Separates and identifies different organic compounds based on their size and affinity to the stationary phase.
Mass Spectrometry: Provides detailed information about the structure and molecular weight of identified compounds.
Atomic Absorption Spectroscopy (AAS): Measures the concentration of specific metal elements in the water.

Nutrient Contaminants:

Types: Primarily nitrogen (nitrates, ammonia) and phosphorus.
Impacts: Excess nutrients can stimulate excessive algae growth (eutrophication) in receiving water bodies, leading to oxygen depletion and ecological imbalance.
Analysis: Standard methods measure total nitrogen and phosphorus concentrations, sometimes with further breakdown into specific forms (e.g., nitrate, ammonia).

Salinity:

Concerns: High salt content can damage crops and reduce soil quality for irrigation.
Analysis: Electrical conductivity (EC) provides a general measure of dissolved salts in water. For detailed analysis, ion chromatography can quantify specific ions like sodium, chloride, and calcium.

Challenges in Analysis:

Emerging Contaminants: New contaminants like microplastics and per- and polyfluoroalkyl substances (PFAS) are a growing concern. Developing effective detection methods for these emerging contaminants is ongoing.
Complexity of Mixtures: Recycled water can contain a complex mixture of contaminants. Analytical methods need to be sensitive enough to detect individual components at low concentrations.
Cost and Time: Some advanced analytical techniques can be expensive and time-consuming. Optimizing methods for cost-effectiveness and rapid analysis is crucial for routine monitoring.

Importance of Analytical Methods:

Effective detection and quantification of contaminants are essential for:

Protecting Public Health: Ensuring recycled water meets safety standards for its intended use.
Environmental Protection: Preventing harmful contaminants from entering the environment through reuse.
Optimizing Treatment Processes: Monitoring data helps evaluate treatment efficiency and identify areas for improvement.

Market overview

The Water Recycle and Reuse Market is estimated to be worth USD 16.1 billion in 2023 and is expected to increase at a compound annual growth rate of 10.8% from 2023 to 2028, reaching USD 27.0 billion by 2028. The main influence of the market is the substantial utilization of water recycling and reuse equipment across diverse end-use industries.

Regulations and standards

Region	Description	Example
European Union	The EU Water Reuse Regulation (2020/741) establishes a framework for safe water reuse across the member states. It classifies reuse water quality into categories (A, B, C, D, E) with varying levels of stringency based on potential health and environmental risks. Each category outlines specific water quality parameters and mandatory minimum treatment levels.	- Category A: Highest quality, suitable for irrigation of edible crops after minimal disinfection (e.g., greens, fruits). Category E: Lowest quality, restricted to industrial applications with minimal human contact (e.g., toilet flushing).
United States Environmental Protection Agency (USEPA)	The USEPA does not have national mandatory regulations for reuse water. However, they provide Guidelines for Water Reuse which offer recommendations for treatment, monitoring, and management practices based on intended use. Many states have adopted or adapted these guidelines into their own regulations.	- The USEPA framework emphasizes a risk-based approach, tailoring requirements to specific reuse applications. Guidelines address factors like public health protection, environmental impacts, and agricultural suitability.
India	The National Framework on safe reuse of wastewater by the National Mission for Clean Ganga (NMCG) provides guidelines for reuse in India. It categorizes reuse water based on quality and outlines minimum treatment requirements. The framework also emphasizes adoption of local regulations based on specific water needs and environmental conditions.	- Similar to the EU, India's framework classifies reuse water into different categories. The framework promotes adoption of advanced treatment technologies for higher quality reuse applications.

Mandatory and Optional Analyses for Reuse Water

The specific analyses required for reuse water depend on regulations and the intended use of the treated wastewater. However, here's a breakdown of common mandatory and optional analyses:

Mandatory Analyses

Microbiological: These analyses are crucial for protecting public health and ensuring the water is free from harmful bacteria, viruses, and parasites. Common tests include:

Total Coliform Bacteria
coli
Fecal Coliform Bacteria

Physical and Chemical: These analyses assess various properties of the water to ensure its suitability for the intended use. They may include:

pH (acidity/alkalinity)
Electrical Conductivity (EC) (salinity)
Total Dissolved Solids (TDS) (dissolved minerals)
Turbidity (cloudiness)
Chlorine Residual (disinfectant level)
Nutrients (nitrogen, phosphorus) - especially important for agricultural reuse

Optional Analyses

Metals: Depending on the source of wastewater and potential industrial contamination, testing for specific metals like lead, cadmium, or chromium might be necessary.
Emerging Contaminants: These include pharmaceuticals, personal care products, and endocrine-disrupting chemicals. Testing for these may be required in specific situations or for research purposes.
Organic Compounds: Analysis for specific organic compounds may be needed if there's a concern about industrial or agricultural runoff in the wastewater source.
Toxicity Tests: These tests assess the overall impact of the treated water on living organisms, particularly for reuse in sensitive environments like aquaculture.

Eurofins role in analysis of recycled water for reuse

Eurofins, a global scientific leader, can play a crucial role in analyzing recycled water for reuse applications. Here's how their expertise can be valuable:

Water Quality Testing: Eurofins has extensive experience in testing water samples for various parameters, including physical, chemical, and microbiological contaminants. This ensures that recycled water meets specific reuse standards set by regulatory bodies.
Microbiological Analysis: Eurofins can analyze the presence of pathogens like bacteria, viruses, and parasites in recycled water. This helps assess the potential health risks associated with reuse.
Emerging Contaminants: Eurofins can also test for emerging contaminants like pharmaceuticals, personal care products, and industrial chemicals that may not be routinely monitored but can be present in recycled water.

By providing a comprehensive analysis of recycled water quality, Eurofins can help ensure its safe and sustainable reuse for various applications, including:

Irrigation: Recycled water can be used for agricultural irrigation, reducing pressure on freshwater resources.
Industrial Processes: Many industries require large volumes of water for cooling and other processes. Recycled water can be a cost-effective and sustainable alternative.
Non-Potable Uses: Recycled water can be used for toilets, laundry, and other non-drinking purposes, reducing reliance on potable water supplies.

Overall, Eurofins' expertise in water quality testing and analysis can play a significant role in promoting the safe and responsible reuse of recycled water, contributing to a more sustainable water management approach.

References

https://eurlex.europa.eu/legalcontent/EN/TXT/PDF/?uri=CELEX:32020R074
https://nmcg.nic.in/writereaddata/fileupload/32_SRTW%20Framework_Final_23_11_2021%20(1).pdf
https://www.epa.gov/sites/default/files/2019-08/documents/2004-guidelines-water-reuse.pdf
https://www.marketsandmarkets.com/Market-Reports/water-recycle-reuse-market-
Tortajada, C. (2020). Contributions of recycled wastewater to clean water and sanitation Sustainable Development Goals. Npj Clean Water, 3(1), 1-6. https://doi.org/10.1038/s41545-020-0069-3