Today water recycling is considered the key to our water crisis. With great breakthroughs in all the areas of science, we have come to a conclusion that only self sustaining and holistic solutions are the way to go forward for a secure future. One of the areas that has been focused globally over the past few years is Water Management which stresses on Waste Water Treatment and Water Recycling. Water Management is essential for our survival as we have a limited supply of potable water on the planet and with deforestation, the rate of replenishment of this resource has deteriorated disastrously over the past decades. Everywhere around the world, waste water treatment for water recycling is stressed upon each day. This not only eases efficient water management but also provides a way for decentralization of the resource. Decentralization is essential for sustainability as it distributes the resource and its management along with its total stock amongst the community. This results in equal and viable distribution all over the community making them self reliant and helps in managing the resource at the community’s level. This paves a way for sustainability. When we talk about water recycling and waste water management, even that can and should be carried out at every level by the community. Over the years technology has had various developments to effectively implement Water Recycling by using Waste Water Treatment or Sewage Treatment Plants.
Earlier these plants were limited to industrial applications, however they have gained popularity amongst the public to be used in residential complexes for water recycling and have various benefits such as:
- 1) Since the treated water can be used for purposes which do not require potable water, such as irrigation, landscaping, washing etc, Waste water treatment plants help in managing the water supply.
- With reuse of water, the water consumption can be decreased which results in reducing the water costs.
- Treated Grey water is full of nutrients and hence very much beneficial to the vegetation and environment.
- With water recycling we are essentially reducing our carbon footprint and giving back to the nature and our ecosystem.
Although most of the Waste Water Treatment Plants have been developed to treat waste water into reusable grey water, with time many projects have come up that use water recycling indirectly for potable purposes. These plants consist of recharging groundwater aquifers and augmenting surface water reservoirs with recycled water.These are often called Groundwater recharge projects. In such projects recycled water is injected or spread into the groundwater aquifers to augment groundwater supplies.
Water Recycling Process
Water Recycling Process uses physical, biological and chemical principles to decontaminate water and make it fit for reuse. It consists of three levels of treatments: Primary Treatment, Secondary Treatment and Tertiary Treatment.
Simple mechanical and physical processes are implemented in Primary treatment which removes approximately half of the contaminants from wastewater.
Bar screens: At the beginning of the water recycling process, the raw sewage is passed through a system of mechanical bar screens which removes large solids such as sticks, rags, and plastic material from the wastewater stream. A horizontal rake on a toothed gear drive removes the captured material out of the chamber for removal to a sanitary landfill.
Grit chamber: The wastewater flows through an aerated grit chamber and where the stream is saturated with very fine air bubbles which encourage settling of the fine grit particles.
Primary clarification: At this point the flow velocity of the wastewater is slowed to encourage solids settling. Biosolids are digested and used for purposes like conditioning the soil or composting.
Biological processes are used in the Secondary treatment which removes most of the remaining contaminants.
Aeration Basins: Oxygen is mixed into the water as it flows through an aeration basin. Here, bacterial microorganisms remove the organic material and convert non-settleable solids to settleable solids which are later captured in final clarifiers.
Final Clarifiers: Most of the solid materials gets thickened and settles out into the final clarifiers but some are returned to the aeration tank to reintroduce incoming water with microorganisms.
Tertiary Treatment is the additional purification or advanced treatment of the water. Once the water reaches this level, water is passed through sand before undergoing chemical disinfection in chlorine contact chambers, which kills any remaining microorganisms and the chlorine is removed using sulfur dioxide. Today we are standing at the crossroads of our future. With water recycling, we can reuse the water supply and manage our water resources effectively. How we handle the crisis today, will determine what our future generations will have to face in order to survive.