effluent

effluent — noun

1. liquid waste containing chemicals or sewage that factories, farms, or treatment

1.nounB2
Definition

liquid waste containing chemicals or sewage that factories, farms, or treatment plants release into natural waterways such as rivers and the ocean.

Example

The factory was fined for releasing untreated effluent into the river near Samir's town.

untreated effluent — waste that has not been cleaned or processed

Élise tested the creek water below the industrial plant's main effluent pipe.

effluent pipe — a pipe that carries liquid waste

Common collocations
  • untreated effluent
  • raw effluent
  • industrial effluent
  • chemical effluent
  • treated effluent
  • effluent discharge
  • effluent treatment
  • effluent pipe
  • toxic effluent
Synonyms
  • sewage

    refers specifically to human and household waste, not industrial chemicals

  • wastewater

    broader term that includes used water from homes and businesses

  • discharge

    can refer to solid, liquid, or gaseous waste being released

  • runoff

    rainwater that carries pollutants from land surfaces, not from pipes or plants

Antonyms
  • fresh water

    clean, unpolluted water from natural sources

Grammar Patterns

effluent + noun (attributive)

uncountable in general reference

Usage Note

Typically uncountable when referring to waste in general ('The river was polluted by effluent'). Becomes countable when specifying different kinds or sources ('Several industrial effluents were found in the sample').

Common Mistakes

The rich effluent businessman bought a new car.
The affluent businessman bought a new car.
'effluent' (waste) and 'affluent' (wealthy) sound similar but have very different meanings.
The river was polluted by many effluents.' (when referring to general waste)
The river was polluted by effluent.
For general reference, use the uncountable form.
Effluent is the same as human sewage.
Sewage is one type of effluent; industrial chemical waste is another.
Sewage is a subset of effluent, not a synonym.

effluent — adjective

Word family

  • effluence
    nounC2
  • efflux
    nounC2
  • influent
    adjectiveC2

Synonym discussion

Sense: noun/1

All four terms describe unwanted liquids, but they differ in origin and scope. 'Sewage' is the narrowest — it refers specifically to human and household waste carried through sewer systems. 'Wastewater' is broader: it includes sewage plus used water from industry, washing, and agriculture. 'Effluent' overlaps with 'wastewater' but carries a stronger environmental and regulatory tone — it is the term used in pollution control laws and environmental impact reports. 'Discharge' is the most general: it can describe any liquid (or gas) being released, whether polluted or not. 'Runoff' differs in source — it is rain or irrigation water that flows over land surfaces, picking up fertilisers, oil, and debris along the way, rather than being released from a pipe or plant. For example, a factory releases 'effluent' from a pipe; a farm field generates 'runoff' after a heavy rain.

sewagewastewater ↗discharge ↗runoff

Etymology

LatinEnglish

The word 'effluent' comes from Latin 'effluentem', meaning 'flowing out'. This is formed from the prefix 'ex-' (out) and the verb 'fluere' (to flow). The noun sense — focusing on liquid waste that flows out — became common in the 19th century during industrialisation, when factory waste and sewage disposal became major environmental concerns. The adjective sense preserves the original Latin meaning of simply 'flowing outward'.