Environmental engineering is the application of
science and
engineering principles to minimise the adverse effects of human activities on the environment (pollution of air, water, and/or land resources). Altough it is widely considered impossible to eliminate all negative impacts, it is thought human effects can be decreased and controled through
public education[?],
conservation, regulations, and the application of good engineering practices (set up of processes, and facilities).
Two of the principal environmental problems are
- the increasing number of humans on Earth. Along this line, one of the first applications of environmental engineering is the removal of sewage from cities, which became increasingly important as population grew. There were (and still is in many countries) initially no treatment : wastes are for example simply brought to the nearest stream. However, since sewage disposal eventually cause damages to natural waters, methods of treating wastewaters prior to discharge were developped. This has evolved into a large industry.
- the second major factor is the rising standard of living in many nations, such as in Europe and Australia. A higher living standard generate more consumption of natural resources and more wastes. The standard of living of developed nations is due in part to development of synthetic chemical industry in the XX century and to the exploitation of fossil fuels for energy production. These industries produceed toxic and hazardous chemicals in great quantities long before they were known to be dangerous. Unlike sewage, even small amounts of these molecules may be harmful, but the technology to detect them at low levels did not existed when the new industries appeared. It was then impossible to detect and identify them as factors in human health or environmental problems. There were initially no attemps to control their production, use and disposal.
"Pollutants" may be chemical, biological, thermal, radioactive, or even mechanical. Environmental engineering emphasizes several areas: process engineering, environmental chemistry, water and wastewater treatment (sanitary engineering), waste reduction, and pollution prevention. It is a branch of civil engineering, chemical engineering and sometimes a branch of public health and mechanical engineering.