Industrial Wastewater Sources And Treatment Methods
Most industrial processes use water and consequently, produce wastewater containing substances that are toxic. Factories producing pharmaceutical products, pesticides, paints, dyes, petrochemicals, or detergents, generate wastewater contaminated with particulates or dissolved by-products. Wastewater from fossil-fuel power plants generally contain mercury, cadmium, chromium, arsenic, selenium and nitrogen compounds in significant levels. Click the link for food industry wastewater treatment.
Wastewaters within agricultural and food processing operations may not have toxic and non-biodegradable content, but such liquid outputs usually have high concentrations of biochemical oxygen demand (BOD) and suspended solids. High levels of antibiotics, growth hormones and parasite control agents from animals may also be present in wastewater generated by slaughter houses. Wastwater from food processing facilities contain considerable amounts of fats, oil or grease (FOG); salt, acids, alkali, compounds used for flavoring; food preservatives and other plant organic material.
Water used as coolant or lubricant in iron and steel industrial plants are contaminated with gasification products like benzene, naphthalene, anthracene, ammonia, phenols, cresols and polycyclic aromatic carbons. High concentrations of toxic substances are found in mine tailings from copper, gold or silver mines contain. Water used in pulp and paper mills contain chloroform, dioxins, furans, phenols and high quantities of suspended solids. Wool processing generates wastewater that has insecticide residues as well as animal fats. Wastewater in the operation of nuclear plants and radio-chemical laboratories are radio-active. Water treatment plants also produce certain by-products that require further treatment.
Untreated wastewater is deemed to be a pollutant. Industries must comply with environmental protection laws which require the treatment of wastewater before being released into the environment (as effluent) or water recycling back for use in the industrial process. Various treatment processes are employed, with several methods able to isolate and accumulate compounds or elements that are re-injected into the industrial process involved, sold for use elsewhere, or rendered inert and disposed off in accordance with relevant regulations.
A common and usually basic stage in wastewater treatment is removal or recovery of suspended solids found in the water. Course-sized solids may easily be segregated as sludge or slurry that can be subjected to further treatment, depending on the chemicals such slurry may contain. Very fine solids (and those with densities approximating that of water) may have to undergo filtration and flocculation techniques. Skimmers may be employed to remove FOG suspended as large oil droplets on the water surface. More complex systems such as API (American Petroleum Institute) oil-water separators, parallel plate separators, or hydrocyclone oil separators may have to be employed for removing emulsified oils.
Conventional sewage treatment with either activated sludge or trickling filter systems are employed for treating biodegradable organic compounds. Synthetic organic materials found in wastewater can be treated through advanced oxidation processing, distillation, adsorption, vitrification, incineration, chemical immobilization and landfill disposal. Leakage of untreated wastewater into the ground may occur, requiring soil remediation techniques to decontaminate the soil as well. Learn more about it here: http://www.ehow.com/list_6904747_types-waste-water.html.