7
Dissolved Organic Matter in Natural Waters
or assimilation (Mostofa et al. 2005a, 2009b; Zhang et al. 2009; Kim
et al. 2006; Li et al. 2008; Yamashita and Jaffé 2008; Carrillo et al. 2002;
Kopáček et al. 2004; Fu et al. 2005). Simultaneously, DOM can release
nutrients upon exposure to natural sunlight in waters (Bronk 2002; Zhang
et al. 2004, 2008; Kim et al. 2006; Vähätalo and Järvinen 2007; Li et al.
2008). Increases in nutrients and autochthonous DOM severely deteriorate
the drinking water quality, but DOM can also balance acidity and alkalinity
through its photoinduced or microbial decomposition (Mostofa et al. 2009a;
Oliver et al. 1983; Wigington et al. 1996; Pace and Cole 2002; Hudson et al.
2003; Kopáćek et al. 2003).
(8) OM can maintain global carbon cycle processes through production, distribution, transportation and decomposition of carbon compounds in the biosphere
(Mostofa et al. 2009a; Brandt et al. 2009; Rutledge et al. 2010; Omar et al.
2010; Ballaré et al. 2011; Zepp et al. 2011; Hedges 1992; Amon and Benner
1994; Ogawa and Tanoue 2003; Freeman et al. 2004; Lavoie et al. 2005;
Fenner et al. 2007a, b; Wolf et al. 2007). The photoinduced and microbial
decomposition of DOM and POM yields CO 2 , CO, CH 4 , DIC (DIC is defined
jointly as dissolved CO 2 , H 2 CO 3 , HCO 3
− , and CO 3
2− ), low molecular weight
DOM and other inorganic ions (Jones and Amador 1993; Miller and Zepp
1995; Lovley and Chapelle 1995; Lovley et al. 1996; Moran and Zepp 1997;
Miller 1998; Conrad 1999; Johannessen and Miller 2001; Ma and Green
2004; Xie et al. 2004; Johannessen et al. 2007; Yoshioka et al. 2007; Brandt
et al. 2009; Rutledge et al. 2010; Omar et al. 2010; Ballaré et al. 2011; Zepp
et al. 2011). The produced CO 2 and CH 4 increase the atmospheric green
house gases and contribute to the global carbon cycle (Davidson and Janssens
2006; Porcal et al. 2009). Elevated atmospheric CO 2 can enhance DOC supply, particularly in peat soils. This is attributed to elevated net primary productivity of plants and increased root exudation of DOC in soil environments,
which ultimately leach into the aquatic ecosystem (Freeman et al. 2004;
Lavoie et al. 2005; Fenner et al. 2007a, b; Wolf et al. 2007; Kang et al. 2001;
Pastor et al. 2003).
(9) Character and energy functions of OM in the water ecosystem. DOM and
POM can provide a major source of energy, in the form of C and N, which
are essential to all living organisms in natural waters (Mostofa et al. 2009a;
Tranvik 1992; Salonen et al. 1992; Wetzel 1984, 1992). Thermal energy
produced during the photoinduced and microbial degradation of DOM and
organic matter, photoinduced redox reactions, microbial loop, as well as
photosynthesis are key drivers in aquatic ecosystems (Mostofa et al. 2009a;
Komissarov 1994, 1995, 2003; Miller and Moran 1997; Sherr and Sherr 1989;
Carrick et al. 1991; Jones 1992; Tranvik 1992; Salonen et al. 1992; Wetzel
1984, 1992; Hedges et al. 2000). DOM itself can provide energy and matter
for the growth of bacterial films on the surface of drinking-water pipes, a process that involves also fulvic and humic acids (humic substances) depending
on their occurrence in groundwater in developing and developed countries
(Mostofa et al. 2009a).
Dissolved Organic Matter in Natural Waters
or assimilation (Mostofa et al. 2005a, 2009b; Zhang et al. 2009; Kim
et al. 2006; Li et al. 2008; Yamashita and Jaffé 2008; Carrillo et al. 2002;
Kopáček et al. 2004; Fu et al. 2005). Simultaneously, DOM can release
nutrients upon exposure to natural sunlight in waters (Bronk 2002; Zhang
et al. 2004, 2008; Kim et al. 2006; Vähätalo and Järvinen 2007; Li et al.
2008). Increases in nutrients and autochthonous DOM severely deteriorate
the drinking water quality, but DOM can also balance acidity and alkalinity
through its photoinduced or microbial decomposition (Mostofa et al. 2009a;
Oliver et al. 1983; Wigington et al. 1996; Pace and Cole 2002; Hudson et al.
2003; Kopáćek et al. 2003).
(8) OM can maintain global carbon cycle processes through production, distribution, transportation and decomposition of carbon compounds in the biosphere
(Mostofa et al. 2009a; Brandt et al. 2009; Rutledge et al. 2010; Omar et al.
2010; Ballaré et al. 2011; Zepp et al. 2011; Hedges 1992; Amon and Benner
1994; Ogawa and Tanoue 2003; Freeman et al. 2004; Lavoie et al. 2005;
Fenner et al. 2007a, b; Wolf et al. 2007). The photoinduced and microbial
decomposition of DOM and POM yields CO 2 , CO, CH 4 , DIC (DIC is defined
jointly as dissolved CO 2 , H 2 CO 3 , HCO 3
− , and CO 3
2− ), low molecular weight
DOM and other inorganic ions (Jones and Amador 1993; Miller and Zepp
1995; Lovley and Chapelle 1995; Lovley et al. 1996; Moran and Zepp 1997;
Miller 1998; Conrad 1999; Johannessen and Miller 2001; Ma and Green
2004; Xie et al. 2004; Johannessen et al. 2007; Yoshioka et al. 2007; Brandt
et al. 2009; Rutledge et al. 2010; Omar et al. 2010; Ballaré et al. 2011; Zepp
et al. 2011). The produced CO 2 and CH 4 increase the atmospheric green
house gases and contribute to the global carbon cycle (Davidson and Janssens
2006; Porcal et al. 2009). Elevated atmospheric CO 2 can enhance DOC supply, particularly in peat soils. This is attributed to elevated net primary productivity of plants and increased root exudation of DOC in soil environments,
which ultimately leach into the aquatic ecosystem (Freeman et al. 2004;
Lavoie et al. 2005; Fenner et al. 2007a, b; Wolf et al. 2007; Kang et al. 2001;
Pastor et al. 2003).
(9) Character and energy functions of OM in the water ecosystem. DOM and
POM can provide a major source of energy, in the form of C and N, which
are essential to all living organisms in natural waters (Mostofa et al. 2009a;
Tranvik 1992; Salonen et al. 1992; Wetzel 1984, 1992). Thermal energy
produced during the photoinduced and microbial degradation of DOM and
organic matter, photoinduced redox reactions, microbial loop, as well as
photosynthesis are key drivers in aquatic ecosystems (Mostofa et al. 2009a;
Komissarov 1994, 1995, 2003; Miller and Moran 1997; Sherr and Sherr 1989;
Carrick et al. 1991; Jones 1992; Tranvik 1992; Salonen et al. 1992; Wetzel
1984, 1992; Hedges et al. 2000). DOM itself can provide energy and matter
for the growth of bacterial films on the surface of drinking-water pipes, a process that involves also fulvic and humic acids (humic substances) depending
on their occurrence in groundwater in developing and developed countries
(Mostofa et al. 2009a).