Blackwater in a
sanitation
Sanitation refers to public health conditions related to clean drinking water and treatment and disposal of human excreta and sewage. Preventing human contact with feces is part of sanitation, as is hand washing with soap. Sanitation syste ...
context denotes
wastewater
Wastewater is water generated after the use of freshwater, raw water, drinking water or saline water in a variety of deliberate applications or processes. Another definition of wastewater is "Used water from any combination of domestic, industrial ...
from toilets, which likely contains
pathogen
In biology, a pathogen ( el, πάθος, "suffering", "passion" and , "producer of") in the oldest and broadest sense, is any organism or agent that can produce disease. A pathogen may also be referred to as an infectious agent, or simply a germ ...
s which may spread by the
fecal–oral route. Blackwater can contain
feces,
urine
Urine is a liquid by-product of metabolism in humans and in many other animals. Urine flows from the kidneys through the ureters to the urinary bladder. Urination results in urine being excreted from the body through the urethra.
Cellular ...
, water and toilet paper from
flush toilet
A flush toilet (also known as a flushing toilet, water closet (WC) – see also toilet names) is a toilet that disposes of human waste (principally urine and feces) by using the force of water to ''flush'' it through a drainpipe to another loca ...
s. Blackwater is distinguished from
greywater
Greywater (or grey water, sullage, also spelled gray water in the United States) refers to domestic wastewater generated in households or office buildings from streams without fecal contamination, i.e., all streams except for the wastewater fro ...
, which comes from sinks, baths, washing machines, and other kitchen appliances apart from toilets. Greywater results from washing food, clothing, dishes, as well as from showering or bathing.
Blackwater and greywater are kept separate in "ecological buildings", such as
autonomous building
An autonomous building is a building designed to be operated independently from infrastructural support services such as the electric power grid, gas grid, municipal water systems, sewage treatment systems, storm drains, communication services, ...
s.
Recreational vehicles often have separate holding tanks for greywater from showers and sinks, and blackwater from the toilet.
Definition
According to one source:
Water coming from domestic equipment other than toilets (e.g., bathtubs, showers, sinks, washing machines) is called greywater. In some sanitation systems, it is preferred to keep the greywater separate from blackwater to reduce the amount of water that gets heavily polluted and to simplify treatment methods for the greywater.
Terminology
Blackwater is a term dating to at least the 1970s and, in
Hong Kong
Hong Kong ( (US) or (UK); , ), officially the Hong Kong Special Administrative Region of the People's Republic of China (abbr. Hong Kong SAR or HKSAR), is a city and special administrative region of China on the eastern Pearl River Delta i ...
regional usage, an alternative term for blackwater is "soil water".
Drainage - Designing Buildings Wiki
/ref>
Treatment processes
Blackwater contains pathogens that must decompose before they can be released safely into the environment. It is difficult to process blackwater if it contains a large quantity of excess water, or if it must be processed quickly, because of the high concentrations of organic material.
Composting
However, if blackwater does not contain excess water, or if it receives primary treatment to de-water, then it is easily processed through composting. The heat produced by naturally occurring thermophilic
A thermophile is an organism—a type of extremophile—that thrives at relatively high temperatures, between . Many thermophiles are archaea, though they can be bacteria or fungi. Thermophilic eubacteria are suggested to have been among the earl ...
microorganisms will heat the compost to over , and destroy potential pathogens.
Blackwater generation can be avoided by making use of composting toilets and vermifilter
A vermifilter (also vermi-digester or lumbrifilter) is an aerobic treatment system, consisting of a Bioreactor, biological reactor containing media that filters Organic matter, organic material from wastewater. The media also provides a habitat f ...
toilets. In certain autonomous buildings, such as earthships, this is almost always present and allows the water requirements of the building (which, with earthships, are self-generated) to be heavily reduced. Besides saving water, composting toilets allow the user to reuse the nutrients found therein (e.g., for growing crops/trees).
See also
* Algae fuel
Algae fuel, algal biofuel, or algal oil is an alternative to liquid fossil fuels that uses algae as its source of energy-rich oils. Also, algae fuels are an alternative to commonly known biofuel sources, such as corn and sugarcane. When made fr ...
* Container-based sanitation
* Constructed wetland
A constructed wetland is an artificial wetland to treat sewage, greywater, stormwater runoff or industrial wastewater. It may also be designed for land reclamation after mining, or as a mitigation step for natural areas lost to land development ...
* Ecological sanitation
* Night soil
Night soil is a historically used euphemism for human excreta collected from cesspools, privies, pail closets, pit latrines, privy middens, septic tanks, etc. This material was removed from the immediate area, usually at night, by workers em ...
References
{{Authority control
Sanitation
Sewerage
Water pollution