POLLUTION
Air pollution has always accompanied civilizations. Pollution started from prehistoric times, when man created the first fires. According to a 1983 article in the journal Science, "soot" found on ceilings of prehistoric caves provides ample evidence of the high levels of pollution that was associated with inadequate ventilation of open fires."[4] Metal forging appears to be a key turning point in the creation of significant air pollution levels outside the home. Core samples of glaciers in Greenland indicate increases in pollution associated with Greek, Roman, and Chinese metal production.Forms of pollution The Lachine Canal in Montreal, Quebec, Canada. Blue drain and yellow fish symbol used by the UK Environment Agency to raise awareness of the ecological impacts of contaminating surface drainage. The major forms of pollution are listed below along with the particular contaminant relevant to each of them: Air pollution: the release of chemicals and particulates into the atmosphere. Common gaseous pollutants include carbon monoxide, sulfur dioxide, chlorofluorocarbons (CFCs) and nitrogen oxides produced by industry and motor vehicles. Photochemical ozone and smog are created as nitrogen oxides and hydrocarbons react to sunlight. Particulate matter, or fine dust is characterized by their micrometre size PM10 to PM2.5.Electromagnetic pollution: the overabundance of electromagnetic radiation in their non-ionizing form, like radio waves, etc., that people are constantly exposed at, especially in large cities. It's still unknown whether or not those types of radiation have any effects on human health, though.Light pollution: includes light trespass, over-illumination and astronomical interference.Littering: the criminal throwing of inappropriate man-made objects, unremoved, onto public and private properties.Noise pollution: which encompasses roadway noise, aircraft noise, industrial noise as well as high-intensity sonar.Plastic pollution: involves the accumulation of plastic products and microplastics in the environment that adversely affects wildlife, wildlife habitat, or humans.Soil contamination occurs when chemicals are released by spill or underground leakage. Among the most significant soil contaminants are hydrocarbons, heavy metals, MTBE,[22] herbicides, pesticides and chlorinated hydrocarbons.Radioactive contamination, resulting from 20th century activities in atomic physics, such as nuclear power generation and nuclear weapons research, manufacture and deployment. (See alpha emitters and actinides in the environment.)Thermal pollution, is a temperature change in natural water bodies caused by human influence, such as use of water as coolant in a power plant.Visual pollution, which can refer to the presence of overhead power lines, motorway billboards, scarred landforms (as from strip mining), open storage of trash, municipal solid waste or space debris.Water pollution, by the discharge of wastewater from commercial and industrial waste (intentionally or through spills) into surface waters; discharges of untreated domestic sewage, and chemical contaminants, such as chlorine, from treated sewage; release of waste and contaminants into surface runoff flowing to surface waters (including urban runoff and agricultural runoff, which may contain chemical fertilizers and pesticides; also including human feces from open defecation – still a major problem in many developing countries); groundwater pollution from waste disposal and leaching into the ground, including from pit latrines and septic tanks; eutrophication and littering.Pollutants Main article: Pollutant A pollutant is a waste material that pollutes air, water, or soil. Three factors determine the severity of a pollutant: its chemical nature, the concentration and the persistence.Pollution control A litter trap catches floating waste in the Yarra River, east-central Victoria, Australia Air pollution control system, known as a Thermal oxidizer, decomposes hazard gases from industrial air streams at a factory in the United States of America. A dust collector in Pristina, Kosovo Gas nozzle with vapor recovery A Mobile Pollution Check Vehicle in India. Pollution control is a term used in environmental management. It means the control of emissions and effluents into air, water or soil. Without pollution control, the waste products from overconsumption, heating, agriculture, mining, manufacturing, transportation and other human activities, whether they accumulate or disperse, will degrade the environment. In the hierarchy of controls, pollution prevention and waste minimization are more desirable than pollution control. In the field of land development, low impact development is a similar technique for the prevention of urban runoff. Practices RecyclingReusingWaste minimisationMitigatingPreventingCompost Pollution control devices Air pollution controlThermal oxidizerDust collection systemsBaghousesCyclonesElectrostatic precipitatorsScrubbersBaffle spray scrubberCyclonic spray scrubberEjector venturi scrubberMechanically aided scrubberSpray towerWet scrubberSewage treatmentSedimentation (Primary treatment)Activated sludge biotreaters (Secondary treatment; also used for industrial wastewater)Aerated lagoonsConstructed wetlands (also used for urban runoff)Industrial wastewater treatmentAPI oil-water separators[38][68]BiofiltersDissolved air flotation (DAF)Powdered activated carbon treatmentUltrafiltrationVapor recovery systemsPhytoremediation
Abhinav Purohit