Environmental Contamination by Heavy Metals

Abstract

The environment and its compartments have been severely polluted by heavy metals. This has compromised the ability of the environment to foster life and render its intrinsic values. Heavy metals are known to be naturally occurring compounds, but anthropogenic activities introduce them in large quantities in different environmental compartments. This leads to the environment's ability to foster life being reduced as human, animal, and plant health become threatened. This occurs due to bioaccumulation in the food chains as a result of the nondegradable state of the heavy metals. Remediation of heavy metals requires special attention to protect soil quality, air quality, water quality, human health, animal health, and all spheres as a collection. Developed physical and chemical heavy metal remediation technologies are demanding costs which are not feasible, time-consuming, and release additional waste to the environment. This chapter summarises the problems related to heavy metal pollution and various remediation technologies. A case study in South Africa mines were also used.

Biosorption of heavy metal polluted soil using bacteria and fungi isolated from soil

“…Heavy metals are generated from both anthropogenic and natural sources and are eventually discharged into the environment [6,7]. The main natural discharge of heavy metals is during volcanic eruptions and weathering of metal-bearing rocks [2].…”

“…The main natural discharge of heavy metals is during volcanic eruptions and weathering of metal-bearing rocks [2]. The discharge of heavy metals through various man-made activities, for example excessive application of chemical fertilizers, wood burning, coal combustion, vehicle exhaust, mining, smelting and incineration [2], has caused a wide spread disruption of the normal biogeochemical cycles of metals causing a larger accumulation of heavy metals in the environment, especially the soil [6][7][8]. The major heavy metals of concern include lead, cadmium, arsenic, mercury, copper and chromium because of their toxic impact on human health; for instance, environmental exposure to high concentrations of heavy metals has been linked with various cancers and kidney issues [9].…”

“…There is also the risk of leaching of heavy metals, and this may contaminate underground water and in turn affect human health, especially those that consume underground water through boreholes and well water [1]. The increase in industrialization and urbanization offers ascend to heavy metal pollution of the environment, which might have resulted from the discharge of effluents containing metals such as lead, cadmium, chromium, nickel and mercury [6,7,15].…”

“…Biosorbents of biological origin particularly various microorganisms have received growing interest for the removal of heavy metal and recovery owing to their greater performance [7,24]. Although biosorption is influenced by many factors such as pH, temperature and contact time [6,25], the use of microorganisms as biosorbent materials offers a selective removal of heavy metals under varied physicochemical properties, adsorption and desorption and another advantage of microorganisms is their high surface-to-volume ratio [7,17].…”

“…Biosorbents of biological origin particularly various microorganisms have received growing interest for the removal of heavy metal and recovery owing to their greater performance [7,24]. Although biosorption is influenced by many factors such as pH, temperature and contact time [6,25], the use of microorganisms as biosorbent materials offers a selective removal of heavy metals under varied physicochemical properties, adsorption and desorption and another advantage of microorganisms is their high surface-to-volume ratio [7,17]. Several microorganisms have been used for biosorption, examples include Bacillus cereus used in Cd [26] and Cu [6] removal, Cellulosimicrobium funkei AR6 and Cellulosimicrobium funkei AR8 used in biosorption of Cr [20,21], Bacillus safensis used to biosorb aluminum [15], Aspergillus niger used for fluoride biosorption [22], and Pugazhendhi et al [6] reported lead biosorption using Ralstonia solanacearum.…”