Table 3

From: Chemical, ecotoxicological characteristics, environmental fate, and treatment methods applied to cyanide-containing wastewater

Biological oxidation

\({{\rm{HCOO}}}_{({\rm{aq}})}^{-}+{{\rm{NH}}}_{{\bf{4}}({\rm{aq}})}^{+}\to {\rm{N}}{{\rm{H}}}_{{\rm{3}}({\rm{aq}})}+{{\rm{HCO}}}_{{\rm{3}}({\rm{aq}})}^{-}\)

(11)

\(\begin{array}{cc}{{\rm{SCN}}}_{({\rm{aq}})}^{-}\to {\rm{N}}{{\rm{H}}}_{3({\rm{aq}})}+{{\rm{HC}}{{\rm{O}}}_{3}^{-}}_{({\rm{aq}})}+{{\rm{HS}}{{\rm{O}}}_{4}^{-}}_{({\rm{aq}})}\end{array}\)

(12)

\(\begin{array}{cc}{\left[{\rm{M}}{\left({\rm{CN}}\right)}_{{\rm{m}}}\right]}_{\left({\rm{aq}}\right)}^{{\rm{n}}-}\to {\rm{N}}{{\rm{H}}}_{3\left({\rm{aq}}\right)}+{{\rm{HCO}}}_{3\left({\rm{aq}}\right)}^{-}+{{\rm{M}}}_{\left({\rm{aq}}\right)}^{{\rm{x}}+}\end{array}\)

(13)

\({{\rm{CN}}}_{({\rm{aq}})}^{-}\to {\rm{N}}{{\rm{H}}}_{3({\rm{aq}})}+{{\rm{HCO}}}_{3({\rm{aq}})}^{-}\)

(14)

Nitrification

\(\begin{array}{cc}{\rm{N}}{{\rm{H}}}_{3\left({\rm{aq}}\right)}+{{\rm{HCO}}}_{3\left({\rm{aq}}\right)}^{-}\to {{\rm{NO}}}_{3\left({\rm{aq}}\right)}^{-}+{{\rm{NO}}}_{2\left({\rm{aq}}\right)}^{-}\end{array}\)

(15)

Anaerobic metabolism

\({{\rm{HCN}}}_{({\rm{aq}})}+{{\rm{S}}}_{({\rm{s}})}^{0}\to {\rm{HSC}}{{\rm{N}}}_{\left({\rm{aq}}\right)}\)

(16)

\({{\rm{HSCN}}}_{({\rm{ac}})}\mathop{\to }\limits^{{2{\rm{H}}}_{2}{\rm{O}}}{{\rm{NH}}}_{3\left({\rm{g}}\right)}+{{\rm{H}}}_{2}{{\rm{S}}}_{({\rm{g}})}+{\rm{C}}{{\rm{O}}}_{2\left({\rm{g}}\right)}\)

(17)

\({{\rm{HCN}}}_{({\rm{aq}})}+3{{\rm{H}}}_{2({\rm{g}})}\to {\rm{C}}{{\rm{H}}}_{4({\rm{g}})}+{\rm{N}}{{\rm{H}}}_{3\left({\rm{g}}\right)}\)

(18)

\(\begin{array}{cc}{{\rm{HCN}}}_{({\rm{aq}})}\mathop{\to }\limits^{{2{\rm{H}}}_{2}{\rm{O}}}{{\rm{HCOO}}}_{({\rm{aq}})}^{-}+{{\rm{NH}}}_{4({\rm{aq}})}^{+}\end{array}\)

(19)

\({{\rm{HCOO}}}_{({\rm{aq}})}^{-}+{{\rm{NH}}}_{4({\rm{aq}})}^{+}\to {\rm{N}}{{\rm{H}}}_{3({\rm{g}})}+{\rm{C}}{{\rm{O}}}_{2\left({\rm{g}}\right)}\)

(20)

\({\rm{C}}{{\rm{O}}}_{2({\rm{g}})}+2{{\rm{H}}}_{2({\rm{g}})}\to {\rm{C}}{{\rm{H}}}_{4\left({\rm{g}}\right)}+{{\rm{O}}}_{2({\rm{g}})}\)

(21)

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