recharge (Mukherjee et al. 2020). Inadequately treated industrial, domestic, and
agricultural wastewater contains higher concentrations of HMs, which are usually
discharged into the river water in many developing countries (Das Gupta 2008; Liu
et al. 2011, 2012; Barsova et al. 2019). Such practices contaminate the river water
and the groundwater systems of the river discharge zones. Chemical weathering of
HM(s)-containing minerals in soils, igneous, and sedimentary rocks (basalt, granite,
shales, clays, and sandstones) and abiotic redox processes can mobilize the HMs into
the environment (Caporale and Violante 2016; Edelstein and Ben-Hur 2018). HMs
can also be released from the soil layers by biogeochemical processes to the surface
water systems through soil runoff and groundwater systems through leaching and
percolation (Haferburg and Kothe 2012). Humans, animals, and aquatic habitants are
exposed to the water HMs through ingestion, dermal contact, and inhalation pathways which can cause several carcinogenic and noncarcinogenic diseases (Singh and
Kumar 2017; Mukherjee et al. 2019; Mukherjee and Singh 2020). Exposure to the
HMs through water may cause tremors; headaches; mental fogginess; anxiety and
depression; infertility; deteriorating eye health; memory losses; kidney dysfunction;
digestive problems; tingling sensations in the hands, feet, and/or around the mouth;
poor immune function; recurrent infections; skin diseases; infertility; or even cancers
to humans. Therefore, it is necessary to remove those contaminants in order to
produce relatively safe water. Several technologies are available for HM removal/
recovery from water which include ion exchange, adsorption, membrane filtration,
chemical precipitation, coagulation-flocculation, and electrochemical treatment.
Several researchers have explored phytoremediation for removal of the toxic HMs.
The objectives of the present chapter are to emphasize (a) the sources, mobility, and
fate of the HMs into the water systems and (b) sustainable remediation approaches of
the HMs.
11.2 Sources of Heavy Metal(loid)s in Water Systems
Heavy metal contaminations in water systems of several regions are primarily
affected by the anthropogenic activities. However, these elements may also get
released from the natural sources.
11.2.1 Natural Sources
Heavy metals (HMs) and metalloids are the naturally occurring elements in the
earth’s crust (Ahmad and Bhattacharya 2019; Barsova et al. 2019). HMs are present
in the constituent matrix of several minerals of the soils and several rocks.
HM-containing minerals undergo dissolution caused by chemical weathering due
to rock-water interaction and continually release HMs into the water systems and
other environments at various degrees and concentrations. Mining process releases
256
I. Mukherjee et al.
agricultural wastewater contains higher concentrations of HMs, which are usually
discharged into the river water in many developing countries (Das Gupta 2008; Liu
et al. 2011, 2012; Barsova et al. 2019). Such practices contaminate the river water
and the groundwater systems of the river discharge zones. Chemical weathering of
HM(s)-containing minerals in soils, igneous, and sedimentary rocks (basalt, granite,
shales, clays, and sandstones) and abiotic redox processes can mobilize the HMs into
the environment (Caporale and Violante 2016; Edelstein and Ben-Hur 2018). HMs
can also be released from the soil layers by biogeochemical processes to the surface
water systems through soil runoff and groundwater systems through leaching and
percolation (Haferburg and Kothe 2012). Humans, animals, and aquatic habitants are
exposed to the water HMs through ingestion, dermal contact, and inhalation pathways which can cause several carcinogenic and noncarcinogenic diseases (Singh and
Kumar 2017; Mukherjee et al. 2019; Mukherjee and Singh 2020). Exposure to the
HMs through water may cause tremors; headaches; mental fogginess; anxiety and
depression; infertility; deteriorating eye health; memory losses; kidney dysfunction;
digestive problems; tingling sensations in the hands, feet, and/or around the mouth;
poor immune function; recurrent infections; skin diseases; infertility; or even cancers
to humans. Therefore, it is necessary to remove those contaminants in order to
produce relatively safe water. Several technologies are available for HM removal/
recovery from water which include ion exchange, adsorption, membrane filtration,
chemical precipitation, coagulation-flocculation, and electrochemical treatment.
Several researchers have explored phytoremediation for removal of the toxic HMs.
The objectives of the present chapter are to emphasize (a) the sources, mobility, and
fate of the HMs into the water systems and (b) sustainable remediation approaches of
the HMs.
11.2 Sources of Heavy Metal(loid)s in Water Systems
Heavy metal contaminations in water systems of several regions are primarily
affected by the anthropogenic activities. However, these elements may also get
released from the natural sources.
11.2.1 Natural Sources
Heavy metals (HMs) and metalloids are the naturally occurring elements in the
earth’s crust (Ahmad and Bhattacharya 2019; Barsova et al. 2019). HMs are present
in the constituent matrix of several minerals of the soils and several rocks.
HM-containing minerals undergo dissolution caused by chemical weathering due
to rock-water interaction and continually release HMs into the water systems and
other environments at various degrees and concentrations. Mining process releases
256
I. Mukherjee et al.