Chemicals industry
A range of industries manufacture or use complex organic chemicals. These include pesticides, paints and dyes, petro-chemicals, pharmaceuticals, plastics, detergents, paper pollution, etc. Waste waters can be contaminated by feed-stock materials, by-products, product material in soluble or particulate form, washing and cleaning agents, solvents and added value products such as plasticizers. Treatment facilities that do not need control of their effluent typically opt for a type of aerobic treatment.
Food and beverages industry
Waste water generated from agricultural and food operations has distinctive characteristics that set it apart from common municipal waste water managed by public or private sewage treatment plants throughout the world. It is biodegradable and nontoxic,
but that has high concentrations of biochemical oxygen demand (BOD) and suspended solids. The constituents of food and agriculture waste water are often complex to predict due to the differences in BOD and pH in effluents from vegetable, fruit, and meat products and due to the seasonal nature of food processing and post harvesting. Vegetable washing generates waters with high loads of particulate matter and some dissolved organics. It may also contain surfactants. Animal slaughter and processing produces very strong organic waste from body fluids, such as blood, and gut contents. This waste water is frequently contaminated by significant levels of antibiotics and growth hormones from the animals and by a variety of pesticides used to control external parasites. Processing food for sale produces wastes generated from cooking which are often rich in plant organic material and may also contain salt, flavourings, coloring material and acids or alkali. Very significant quantities of oil or fats may also be present.
but that has high concentrations of biochemical oxygen demand (BOD) and suspended solids. The constituents of food and agriculture waste water are often complex to predict due to the differences in BOD and pH in effluents from vegetable, fruit, and meat products and due to the seasonal nature of food processing and post harvesting. Vegetable washing generates waters with high loads of particulate matter and some dissolved organics. It may also contain surfactants. Animal slaughter and processing produces very strong organic waste from body fluids, such as blood, and gut contents. This waste water is frequently contaminated by significant levels of antibiotics and growth hormones from the animals and by a variety of pesticides used to control external parasites. Processing food for sale produces wastes generated from cooking which are often rich in plant organic material and may also contain salt, flavourings, coloring material and acids or alkali. Very significant quantities of oil or fats may also be present.
Iron and steel industry
The production of iron from its ores involves powerful reduction reactions in blast furnaces. Production of coke from coal in coking plants also requires water cooling and the use of water in by-products separation. Cooling waters are inevitably contaminated with products especially ammonia and cyanide. Contamination of waste streams includes gasification products such as benzene, naphthalene, anthracene, cyanide, ammonia, phenols, cresols together with a range of more complex organic compounds known collectively as polycyclic aromatic hydrocarbons. Final treatment of iron and steel products before onward sale into
manufacturing includes pickling in strong mineral acid to remove rust
and prepare the surface for tin or chromium plating or for other surface
treatments such as galvanization or painting. The conversion of iron or steel into sheet, wire or rods requires hot and cold mechanical transformation stages frequently employing water as a lubricant and coolant. Contaminants include hydraulic oils, tallow and particulate solids. The two acids commonly used are hydrochloric acid and sulfuric acid. Many steel industry waste waters are contaminated by hydraulic oil also known as soluble oil.