Phenolic compounds exist in water bodies due to the discharge of polluted wastewater from industrial, agricultural and domestic activities into water bodies. They also occur as a result of natural phenomena. These compounds are known to be toxic and inflict both severe and long‐lasting effects on both humans and animals. They act as carcinogens and cause damage to the red blood cells and the liver, even at low concentrations. Interaction of these compounds with microorganisms, inorganic and other organic compounds in water can produce substituted compounds or other moieties, which may be as toxic as the original phenolic compounds. This chapter dwells on the sources and reactivity of phenolic compounds in water, their toxic effects on humans, and methods of their removal from water. Specific emphasis is placed on the techniques of their removal from water with attention on both conventional and advanced methods. Among these methods are ozonation, adsorption, extraction, photocatalytic degradation, biological, electro‐Fenton, adsorption and ion exchange and membrane‐based separation.
Part of the book: Phenolic Compounds
Recently, several pollutants such as dyes, pharmaceuticals and phenolic compounds, which can cause toxic effects to human health, have identified in water resources. Water pollution has extensively studied and several conventional techniques, such as chemical treatment, adsorption, biological treatment, and membrane-based separation, have adopted for pollutants removal from wastewater/ water resources. However, these techniques had led to the production of soluble refractory organic compounds and health-threatening bacteria that are hard to be removed. Recently, photocatalysis has considered as one of the most viable technology for water treatment using sunlight to eliminate harmful bacteria and pollutants owing to its cost-effectiveness and high efficiency. Metal oxide and polymers have become promising materials for water treatment owing to their properties, such as surface mobility, large surface area and superb magnetic and optical properties. This book chapter discusses recent design and synthesis of visible light response polymer/metal oxide nanocomposite through several synthetic strategies for water treatment. The results show that the polymer-metal oxide nanocomposite possesses a superior photodegradation activity toward pollutants under simulated visible light. Major challenges in polymer-metal oxide nanocomposite synthesis and future research perspectives for developing alternate synthesis methodologies are also discussed.
Part of the book: Descriptive Inorganic Chemistry Researches of Metal Compounds
Bismuth-based nanoparticles are a unique category of materials that possess interesting properties such as excellent chemical, electrical, optical and catalytic activities among others. The application of bismuth-based nanoparticles as photocatalytic materials has caught the interest of the scientific community in recent times due to these unique properties. Consequently, a number of data have been generated in relation to the photocatalytic application of these nanoparticles. This chapter intends to organise and provide the recently generated information on the use of bismuth-based nanoparticles in photocatalytic degradation processes. A detailed discussion is provided on bismuth-based nanoparticles including bismuth chalcogenides, bismuth vanadate, bismuth oxyhalides and other bismuth-related nanoparticles. Attention was also paid to the modification of these nanoparticles to improve their photocatalytic activities. The application of the modified nanoparticles in various photocatalytic processes with emphasis on water treatment, waste gas treatment, hydrogen production and air purification has also been thoroughly discussed.
Part of the book: Bismuth