Index >> Microbes and Hydrosphere>>Microbiology of Water

Through the natural water cycle, the earth has recycled and reused water for millions of years. Water recycling, though, generally refers to projects that use technology to speed up these natural processes. Water recycling is often characterised as 'unplanned' or' planned'. A common example of unplanned water recycling occurs when cities draw their water supplies from rivers that receive waste water discharges upstream from these cities. Water from these rivers has been reused, treated and piped into the water supply a number of times before the last downstream use withdraws the water. Planned projects are those that are developed with the goal of beneficially reusing a recycled water supply.

There are two grades of recycled water produced normally: one is used for industry and the other for irrigation. Recycled water is safe for human contact, but it is not intended for drinking. Recycled water has been used extensively throughout the United States - including for food crops, over groundwater aquifers and in recreational lakes- for the past 40 years with no negative health impacts.

Throughout the world, alternative systems designed to mimic nature are operating to address the problems of conventional wastewater treatment facilities by making use of man-made ponds, constructed wetlands and designed soil filters to transform wastewater. At the Triangle School Wastewater Treatment Facility in Chatham County, North Carolina, water is being recycled for toilet flushing, thus helping the fishes to feed. Thus the wastewater is treated in a greenhouse, where it is used to produce plants and fish in an integrated cultivation system. In the case of less wealthy countries with serious health hazards resulting from insufficient sewage treatment facilities, affordable effective treatment alternatives incorporating large ponds and marshes are dramatically altering the quality of life. In Lima, Peru, water is treated by a series of ponds teaming with algae and organisms and fueled by sunlight. After 20 days, water is safe for reuse and feeds the fish ponds where phytoplankton gobble up remaining nutrients. Fish are harvested for human consumption and the sludge from the treatment ponds is used as a fertiliser on agricultural fields.