ABSTRACT
The accumulation of discharged of unwanted industrial by-products released into the environment without treatment is harmful. Effective treatment is needed before industrial wastewaters are discharged into the environment or reused for irrigation, livestock, and groundwater recharge and for many other purposes. Natural treatment systems are environmentally friendly and use solar-driven biological processes to treat pollutants. CWs have been used for decades for the treatment of different types of wastewater and have been recognized as a reliable wastewater treatment technology. Large volumes of fresh water are extracted and consumed for use by petroleum industries in the process of refining crude oil and as cooling agent. Contamination of water and lands by petroleum chemicals is a global issue and is of particular concern in developing countries such as Nigeria where industrial pollution is one of its major problems. The chapter also presents an overview of the key concepts discussed in this book.
