Toxic Wastewater - How it is Caused and How You Can Prevent It

The toxicity of municipal effluents depends on aeffluents as well as toxic sewage.
variety of factors, including the size andMany chemicals detected in municipal effluents are
characteristics of the sewer-shed, the type andhydrophobic and may tend to adsorb particles in the
efficiency of treatment, the disinfection processeseffluent or sediments in the receiving environment,
and the physical, chemical & biologicalthan remain in the water phase. The distribution of
characteristics of the receiving waters.these chemicals may therefore differ considerably
In many cases, the acute toxicity of the municipalfrom more soluble compounds, which will tend to
wastewater effluents is due to unionized ammonia, inmove with the effluent plume.
the case of chlorinated effluents, it is because ofHydrophobic wastewater toxic chemicals may also
total residual chlorine that can make wastewatertend to bio-accumulate in organisms and move
toxic. Other causes of wastewater contaminationthrough food webs. The distribution and fate of
including cyanide, sulfides, phenols, surfactants andcontaminants in the environment is extremely
heavy metals, such as copper, zinc and chromium,complex. It is dependent on the physical and chemical
also contribute to acute or chronic toxicity.characteristics of the chemicals as well as the
Many factors including pH, hardness, dissolved organicphysical, chemical and biological characteristics of the
carbon and temperature can moderate the toxicity inreceiving environment.
the water treatment plant effluent or receivingAmmonia, chloramines, nonyl phenol and its
environment. Despite considerable investment inethoxylates and textile mill effluents are associated
treatment systems, acute and chronic toxicitywith municipal effluents and have been known to
remains a concern in many sites receiving municipalmake wastewater toxic.