Nature's Voice Our Choice

Waste Water Treatment Using Aquatic Plants
and Constructed Wetlands

The Need for a Simple Natural System to Treat and Reuse Waste Water

In Developing Cities throughout the world, over 1 billion people are living without access to safe drinking water.  In addition, they do not have access to water for irrigation and small industrial uses that could provide economic solutions and a path out of poverty. 

Waste Water Dumped in Slums and Open Lots in Developing Cities

Nature's Voice Our Choice has developed a Waste Water Treatment system that treats water for reuse in the irrigation of agriculture, building, and small industry processes.  This system is built using simple, locally available materials and uses local aquatic plant species to treat the waste water.

How the system works:  In a conventional Waste Water Treatment Plant there are 3 phases: Primary, Secondary, and Advanced treatment.  The same is true with natural systems.  However, the plants and micro-organisms (bacteria) are performing all the work. 

Primary Treatment:  Waste water influent enters the settling tank from septic trucks or collection pipes.  Sedimentation of solids of solids occurs.  Waste water then flows by gravity to the first of a series of basins containing aquatic plants.

Diagram of Treatment Process

Advanced treatment:  Filtration through subsurface flow constructed wetlands trenches containing sand, gravel, and a diverse array of wetland plants.  This phase provides typical gravel and sand filtration.  However, the presence of wetlands plants prevents the need to backwash the system thus reducing maintenance requirements.  The wetland plants take in the remaining unwanted nutrients left in the water.

Arial View of Waste Water Treatment System

Aeration Requirements:  The primary working component of this system is Aerobic (beneficial) bacteria.  As described above these bacteria thrive in aerobic (high oxygen) environments.  During the day, through photosynthesis, plants provide dissolved oxygen in water, however, at night they use oxygen.  Therefore to maintain an oxygen rich environment where bacteria can thrive; it is necessary to aerate the ponds twice a day.  Once in the evening for 2 hours to provide needed oxygen throughout the night and once in the morning to replenish depleted oxygen supplies.

Recycle Flow Requirements:  Bacteria is the only living organism that has the ability to continuously naturally genetically modify itself to operate at maximum performance in its environment.  In nature, the bacteria’s environment is constantly changing and this ‘Chaos’ is what forces the bacteria to stay active and effective.  In a constructed controlled system with the same influent, bacteria can become stagnant, resistant, and less effective overtime.  Therefore, by varying the recycle flow from the final basin to the other basins, we can continuously ‘change’ the environment and ensure that the bacteria remain active.  This also adds some aeration to the system.

Energy Needs:  The system is designed so that water flows by gravity between the basins.  The minimal energy needed for aeration and recycle flow can be achieved with solar panels or simple wind turbines.

Mosquito Control:  Frogs, Mosquito Fish, and or catfish are introduced into the system to eliminate the mosquito problem associated with standing water and help to create a balanced ecosystem.