Every type of manufacturing industry consumes energy and raw materials, and the environmental impacts of industrial activities are greater if the materials used are non-renewable. Different industrial activities affect the environment in different ways, as described below.
- carry the risk of explosions, fires and spills of hazardous substances into water bodies;
- may result in emissions of particulate matter, sulphur dioxide (SO2), nitrogen oxide (NOx), carbon monoxide (CO), volatile organic compounds (VOCs) and other organic chemicals, depending on the methods used and the end product;
- consume water for processing and cooling;
- affect water quality by releasing organic compounds, heavy metals (cadmium, mercury), suspended solids, organic matter, phenols and cyanide;
- produce waste that contaminates soil; and
- create waste disposal problems.
Paper and pulp production
Environmental hazards include:
- emissions of SO2, NOx, mercaptans, chlorine compounds and dioxins into the atmosphere; and
- the release of suspended solids, organic matter, chlorinated organic compounds and toxins into water bodies.
Cement, glass and ceramics production
Iron and steel industry
- pollute the air with dust, chromium, lead, arsenic, SO2, vanadium, hydrogen fluoride, soda ash, potash, silica and fluorine compounds;
- contaminates processing water with oils and heavy metals;
- requires the extraction of raw materials; and
- releases metals that cause soil contamination and waste-disposal problems.
- release a wide range of pollutants;
- may result in emissions of ultraviolet and infrared radiation, as well as ionising radiation, from heat sources or heated materials;
- carry the risk of explosions and fires; and
- consume water and affect water quality by emitting organic matter, tars and oils, suspended solids, metals, benzene, phenols, acids, sulphides, sulphates, ammonia, cyanide, fluoride, lead and zinc.
Non-ferrous metallurgical industry
The production of non-ferrous metals:
- results in emissions of particulate matter, SO2, NOx and lead; and
- contaminates scrubber water with heavy metals.
The process units in refining plants:
- release emissions of hazardous gases, such as sulphur and NOx, hydrogen sulphide (H2S), hydrocarbons, benzene, CO, carbon dioxide (CO2), particular matter, toxic organic compounds and odours;
- are vulnerable to the risk of explosions and fires;
- take in water for cooling and return it to its source at a higher temperature, causing thermal pollution that decreases oxygen and affects ecosystems; and
- release hydrocarbons, mercaptans, caustic substances, oil, phenols, chromium and effluents from gas scrubbers.
Leather tanning techniques:
- produce emissions of dust, H2S, CO2 and chromium compounds; and
- release effluents containing suspended solids, sulphates and chromium.
The production of foods and beverages:
- depends directly on the natural environment for the supply of raw materials; and
- involves extensive processing that has a considerable potential impact on the environment.