Blackwater vs Greywater
Without water life would be impossible. It is very important for the survival of man and all living things. We drink it to quench our thirst, use it to grow our food, to cleanse our bodies and utensils, and for recreation and exercise.
In the daily activities and chores where we use water, most of it is collected as wastewater. When we take a shower or wash dishes, we produce wastewater which is usually collected in tanks.
Wastewater is classified into two categories, blackwater and greywater. They must be kept in separate tanks because although they are both used water, they have different levels of contamination and must be treated differently.
They can be recycled and used for watering plants and cleaning. They can be recycled through filtration, composting, distillation, or several other mechanical or biological treatment systems.
Blackwater is wastewater from bathrooms and toilets that contain fecal matter and urine. Also called sewage or brown water, it can carry disease causing bacteria that are harmful to man.
It can also refer to floodwater that usually comes from overflowing bodies of water as a result of heavy rain, typhoon, hurricanes, or tsunamis that combine with sewage water that can be laden with bacteria.
In recycling and treating blackwater for use as fertilizer, it must be processed and decomposed properly to destroy bacteria. Heat that is generated in composting can kill bacteria that blackwater contains.
There are composting and vermicomposting toilets available now. Some industrial and business organizations are already using them to help reduce blackwater.
Greywater is wastewater that comes from sinks, washing machines, and bathtubs. It contains a lower level of contaminants than blackwater and is easier to treat and process.
It can even be used directly in home gardens provided that there are no harmful chemicals like soap and detergents in them that can harm the plants and the soil.
Recycled greywater can be used for irrigation and in constructed wetlands. If the greywater is from the sink, food particles in it can nourish plants. It can also be used for washing and flushing toilets.
In times of drought, recycled greywater is very useful. The flow of greywater from washing dishes or clothes can even be used to heat water for bathing, reducing energy use.
Although there are some people who think that recycling blackwater and greywater in homes for use in washing machines can entice people to use more water rather than conserve it, using recycled wastewater is still good, especially in places where water is scarce.
People should be properly educated and informed about how to use water in such a way that will help in its conservation.
Summary
1. Blackwater is wastewater from toilets, while greywater is wastewater from sinks, dishwashers, bathtubs, and washing machines.
2. Blackwater is contaminated with disease carrying bacteria, while greywater has lesser contaminants.
3. Blackwater can only be recycled as fertilizer for plants, while recycled greywater can be used for irrigation, for flushing toilets, and for cleaning cars and floors.
4. Blackwater is more hazardous than greywater.