Suspended solids refers to small solid particles which remain in

suspension Suspension or suspended may refer to: Science and engineering * Suspension (topology), in mathematics * Suspension (dynamical systems), in mathematics * Suspension of a ring, in mathematics * Suspension (chemistry), small solid particles suspen ...

in water as a

colloid A colloid is a mixture in which one substance consisting of microscopically dispersed insoluble particles is suspended throughout another substance. Some definitions specify that the particles must be dispersed in a liquid, while others exten ...

or due to motion of the water. Suspended solids can be removed by

sedimentation Sedimentation is the deposition of sediments. It takes place when particles in suspension settle out of the fluid in which they are entrained and come to rest against a barrier. This is due to their motion through the fluid in response to t ...

if their size or density is comparatively large, or by filtration. It is used as one indicator of

water quality Water quality refers to the chemical, physical, and biological characteristics of water based on the standards of its usage. It is most frequently used by reference to a set of standards against which compliance, generally achieved through ...

and of the strength of

sewage Sewage (or domestic sewage, domestic wastewater, municipal wastewater) is a type of wastewater that is produced by a community of people. It is typically transported through a sewer system. Sewage consists of wastewater discharged from residenc ...

, or

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, industri ...

in general. It is an important design parameter for

sewage treatment Sewage treatment (or domestic wastewater treatment, municipal wastewater treatment) is a type of wastewater treatment which aims to remove contaminants from sewage to produce an effluent that is suitable for discharge to the surrounding e ...

processes. It is sometimes abbreviated SS, but is not to be confused with

settleable solids Settling is the process by which particulates move towards the bottom of a liquid and form a sediment. Particles that experience a force, either due to gravity or due to centrifugal motion will tend to move in a uniform manner in the direction e ...

, also abbreviated SS, which contribute to the blocking of sewer pipes.

Explanation

Suspended solids are important as

pollutant A pollutant or novel entity is a substance or energy introduced into the environment that has undesired effects, or adversely affects the usefulness of a resource. These can be both naturally forming (i.e. minerals or extracted compounds like o ...

s and

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 ger ...

s are carried on the surface of particles. The smaller the particle size, the greater the total surface area per unit mass of particle in grams, and so the higher the pollutant load that is likely to be carried.

Removal

Removal of suspended solids is generally achieved through the use of

and/or

water filter A water filter removes impurities by lowering contamination of water using a fine physical barrier, a chemical process, or a biological process. Filters cleanse water to different extents, for purposes such as: providing agricultural irrigation ...

s (usually at a municipal level). By eliminating most of the suspended solids in a water supply, the significant water is usually rendered close to drinking quality. This is followed by

disinfection A disinfectant is a chemical substance or compound used to inactivate or destroy microorganisms on inert surfaces. Disinfection does not necessarily kill all microorganisms, especially resistant bacterial spores; it is less effective than s ...

to ensure that any free floating pathogens, or pathogens associated with the small remaining amount of suspended solids, are rendered ineffective.

Effectiveness of filtering

The use of a very simple

cloth filter A cloth filter is a simple and cost-effective appropriate technology method for reducing the contamination of drinking water, developed for use mainly in Bangladesh. Water collected in this way has a greatly reduced pathogen count. Though not al ...

, consisting of a folded cotton

sari A sari (sometimes also saree or shari)The name of the garment in various regional languages include: * as, শাৰী, xārī, translit-std=ISO * bn, শাড়ি, śāṛi, translit-std=ISO * gu, સાડી, sāḍī, translit-std ...

, drastically reduces the load of cholera carried in the water, and is suitable for use by the very poor; in this case, an

appropriate technology Appropriate technology is a movement (and its manifestations) encompassing technological choice and application that is small-scale, affordable by locals, decentralized, labor-intensive, energy-efficient, environmentally sustainable, and loca ...

method of disinfection might be added, such as

solar water disinfection Solar water disinfection, in short SODIS, is a type of portable water purification that uses solar energy to make biologically-contaminated (e.g. bacteria, viruses, protozoa and worms) water safe to drink. Water contaminated with non-biological age ...

. A major exception to this generalization is

arsenic contamination of groundwater Arsenic contamination of groundwater is a form of groundwater pollution which is often due to naturally occurring high concentrations of arsenic in deeper levels of groundwater. It is a high-profile problem due to the use of deep tube wells for w ...

, as

arsenic Arsenic is a chemical element with the symbol As and atomic number 33. Arsenic occurs in many minerals, usually in combination with sulfur and metals, but also as a pure elemental crystal. Arsenic is a metalloid. It has various allotropes, bu ...

is a very serious pollutant which is soluble, and thus not removed when suspended solids are removed. This makes it very difficult to remove, and finding an alternative water source is often the most realistic option.

References

Water {{Waste-stub

Explanation

Removal

Effectiveness of filtering

See also

References