Glossary
- Decantation (sedimentation)
- Gravity separation of water suspension solids. Laminar decantation supports a sedimentation rate up to one hundred times higher than classical procedures and reduces soil impregnation considerably.
- Denitrification
- The second stage in the biological elimination of nitrogen, carried out in particular in sewage plants. Denitrification is the reduction of nitrates (NO3-) into nitrogen gas (N2) by anoxic bacteria (lacking oxygen in its dissolved form).
- Desalination
- An operation used to transform seawater into vapour without any dissolved impurities by heating it or reducing its pressure.
- Desanding
- Gravitational separation in wastewater, of gravel, sand, and other materials with a density higher than that of water.
- Dioxin
- Chemical compound resulting from the combustion of organic matter. 210 types of dioxin exist, 17 of which are considered to be harmful.
- Disinfection
- Treatment designed to reduce pathogenic activity under a defined threshold. Example: a curing process using medium-pressure ultraviolet lamps.
- Distillation
- Distillation uses evaporation to separate the impurities from water. The drawback is that it consumes large quantities of thermal energy. This explains why the techniques involved have developed to a greater degree in the gas and oil-producing countries. The advantage of the technique is that in order to evaporate, water does not require pre-processing.
- DW (domestic waste)
- Waste resulting from household consumption and collected by traditional or selective collection.
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