There are a few ways that watercress can be used in contaminated water at a large scale:

1. Phytoremediation: Watercress can be used as a plant in a phytoremediation process, where it absorbs contaminants from the water and helps to clean it. This process involves growing watercress in contaminated water, allowing the plant to absorb pollutants such as heavy metals and chemicals, and then harvesting and disposing of the contaminated plant material.
2. Constructed wetlands: Watercress can be grown in constructed wetlands, where it helps to filter and clean contaminated water as it passes through the wetland. The watercress absorbs contaminants, while other plants and microorganisms in the wetland help to break down pollutants and improve water quality.
3. Biofiltration: Watercress can also be used in biofiltration systems, where contaminated water is passed through a bed of watercress to remove pollutants. The watercress absorbs contaminants such as nitrates and phosphates, improving water quality as it passes through the system.
Overall, watercress can be a valuable tool in cleaning contaminated water at a large scale, and can be used in a variety of ways to help improve water quality.
What are the True gaps will taken into consideration for future research studies

Some potential gaps for future research studies on the use of watercress in contaminated water remediation could include:

1. Understanding the long-term effectiveness of using watercress in phytoremediation, constructed wetlands, and biofiltration systems. It is important to investigate how well watercress can sustainably remove contaminants from water over extended periods of time.
2. Optimizing the conditions for watercress growth and pollutant removal. Research could focus on identifying the ideal water quality parameters, nutrient levels, and environmental conditions for maximizing the efficiency of watercress in cleaning contaminated water.
3. Assessing the potential risks and limitations of using watercress in large-scale water treatment systems. It is important to investigate any potential negative impacts of using watercress, such as the accumulation of pollutants in the plant tissue or impacts on other organisms in the ecosystem.
4. Exploring novel technologies and approaches for incorporating watercress into water remediation processes. Future research could investigate innovative ways to enhance the efficiency and effectiveness of watercress in cleaning contaminated water, such as genetic engineering or bioreactor systems.
Overall, future research studies should aim to address these gaps in knowledge to further advance the use of watercress as a sustainable and effective solution for treating contaminated water.