Md. Saffat Hossain

Water, a natural element which we need everyday and every moment. We use water for drinking, washing, construction, cooking, and all over industry and life are dependent on water. In the world, about 97.4 percent of all water is salt water, with fresh water making up only 2.6 percent of all water on Earth. Of the 2.6 percent of freshwater, 72.5 percent is frozen, 28.15 percent is groundwater, and 0.30 percent is fresh surface water. So it is important to use water efficiently otherwise life will fall in danger on earth and already many of the cities are suffering from shortage of water badly. As we need water and we also pollute water everyday and every moment. Especially developing countries are polluting water just because of their industries and production houses. It is important to use water and to be economically rich for a country and it is also important for everyone to save the earth's water. So we have to reuse and recycle the used water as much as we can.

Water recycling and reuse are essential for sustainable water management, especially in regions facing water scarcity. By treating and reusing wastewater, we can reduce our reliance on freshwater sources, conserve this precious resource, and minimize the environmental impact of wastewater discharge. Recycled water can be used for various purposes, including irrigation, industrial processes, toilet flushing, and even groundwater recharge. This practice not only helps alleviate water shortages but also reduces the strain on natural ecosystems and improves water quality in rivers and lakes.

In industries, there are mostly two systems to reuse or recycle the polluted water. They are the Effluent Treatment Plant (ETP) and Water Treatment Plant (WTP). ETP makes water to reuse for external works, and WTP recycles the water and makes it fresh and clear to the earth.

An Effluent Treatment Plant is a crucial component of water reuse strategies. These specialized facilities are designed to treat industrial wastewater, removing contaminants and pollutants before it is either safely discharged into the environment or recycled for reuse within the industrial process. ETPs employ various treatment methods, including physical, chemical, and biological processes, to purify the wastewater to meet specific quality standards. By effectively treating wastewater, ETPs contribute to environmental protection, resource conservation, and sustainable industrial practices. Effluent Treatment Plants (ETPs) are specifically designed to treat industrial wastewater, transforming it from a pollutant into a reusable resource.

Firstly, wastewater generated from industrial processes is collected and channeled into the ETP. Then start the process of removing large debris, such as grit and sand, through screening and grit removal processes. After removing large particles, the next stage focuses on removing suspended solids through processes like sedimentation and flotation. The next stage is 'Secondary Treatment.' This stage typically involves biological processes, such as activated sludge or trickling filters, to break down organic matter and reduce biochemical oxygen demand (BOD). There is an optional stage that aims to remove specific pollutants, such as nutrients (nitrogen and phosphorus), heavy metals, or pathogens, using advanced technologies like membrane filtration or chemical precipitation. And the final stage is 'Disinfection' to eliminate harmful microorganisms, often using chlorine or ultraviolet light. The treated water makes it easy to reuse water for Watering gardens, parks, and golf courses; cooling towers, boiler feedwater, and process water; non-potable water for flushing toilets; or groundwater recharge.

A Water Treatment Plant (WTP) plays a crucial role in water recycling by purifying wastewater to meet specific quality standards. WTPs employ various treatment processes, including physical, chemical, and biological methods, to remove contaminants and pollutants from the wastewater. This treated water can then be reused for various purposes, such as irrigation, industrial processes, toilet flushing, and even groundwater recharge. By effectively treating wastewater, WTPs contribute to water conservation, environmental protection, and sustainable water management practices.

Water Treatment Plants (WTPs) play a crucial role in water recycling by purifying wastewater to meet specific quality standards. This process starts with removing large debris and grit from the wastewater, preparing it for further treatment. Then the wastewater is passed through sedimentation tanks, allowing suspended solids to settle at the bottom. This process removes a significant portion of organic matter and other pollutants. After that, the water goes to Secondary Treatment. This is the biological treatment phase where microorganisms break down organic matter into simpler substances. This process significantly reduces the biochemical oxygen demand (BOD) and other organic pollutants. Nutrients, pathogens, and other specific contaminants are removed by Tertiary Treatment. Finaly the disinfection started. The treated water can then be reused for various purposes, such as irrigation, industrial processes, toilet flushing, or even groundwater recharge. By effectively treating wastewater, WTPs contribute to water conservation, environmental protection, and sustainable water management practices.

According to the benefit of nature, WTP is better than ETP. But there are some barriers to using WTPs for water recycling compared to ETPs. While Water Treatment Plants (WTPs) can be adapted for water recycling, there are several challenges compared to using dedicated Effluent Treatment Plants (ETPs) such as the infrastructure of existing ETP, capacity, concerns about the safety of recycled water, discomfort, and funding for making new WTP.

In Bangladesh, where water scarcity and pollution are significant challenges, adapting Water Treatment Plants (WTPs) for water recycling offers substantial economic benefits like reduced reliance on freshwater sources, sustainable water management, agricultural productivity and reduced water costs, industrial growth, environmental benefits (reduced pollution, improved water quality), and economic development. To achieve all of this, we need to create a mentality for investing in advanced water treatment technologies, upgrading existing ETPs, WTPs, and increasing the volume of wastewater. Raising public awareness about the benefits of water recycling is essential to overcoming potential resistance and ensuring community acceptance. A proper supportive regulation is needed to encourage water recycling and ensure safety.

Water is limited, but we have the opportunity to recycle the wastewater and to be efficient while using water. It is the high time where many cities are suffering a shortage of water, where we have much water and the time to save water. So take steps from every stage to prevent the scarcity of water for the upcoming future.

The writer is a Masters of Science Govt. Shahid Suhrawardy College