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Effects of electrolytes on the reduction of 2,4‐dinitrotoluene by zero‐valent iron
Author(s) -
Fan JinHong,
Wang HongWu,
Wu DeLi,
Ma LuMing
Publication year - 2010
Publication title -
journal of chemical technology and biotechnology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.64
H-Index - 117
eISSN - 1097-4660
pISSN - 0268-2575
DOI - 10.1002/jctb.2407
Subject(s) - chemistry , zerovalent iron , sulfate , reactivity (psychology) , environmental remediation , degradation (telecommunications) , electrolyte , nuclear chemistry , inorganic chemistry , contamination , organic chemistry , medicine , ecology , telecommunications , alternative medicine , electrode , pathology , adsorption , computer science , biology
BACKGROUND: Dinitrotoluenes (DNTs) are environmentally persistent, making the remediation of contaminated streams and groundwater difficult. Zero‐valent iron (Fe 0 ) can be used as an electron source for the reduction of recalcitrant DNTs in waste‐water and thus enhance their biodegradability. However, little is known about the qualitative effects of major anions and cations present in waste‐water on the reduction of DNTs by Fe 0 . RESULTS: The presence of Na 2 SO 4 and NaCl at levels between 0.25 and 2 mmol L −1 was observed to enhance the reactivity of Fe 0 towards 2,4‐DNT. The positive effect of K 2 SO 4 is stronger than that of Na 2 SO 4 at the same level (1 mmol L −1 ). Varying (NH 4 ) 2 SO 4 from 0.1 to 1.0 mmol L −1 improved the efficiency of 2,4‐DNT degradation by Fe 0 . The effects of varying NaNO 3 and NaNO 2 from 0 mmol L −1 to 4.7 mmol L −1 and 0 mmol L −1 to 5.8 mmol L −1 , respectively, were also investigated. Both NaNO 3 and NaNO 2 at low concentration improved the efficiency of 2,4‐DNT degradation by Fe 0 , however, at high concentration, inhibiting effects appeared. CONCLUSION: SO 4 2− , Cl − , Na + , K + and NH 4 + notably enhanced 2,4‐DNT reduction by Fe 0 at the tested concentrations. The positive effect of K + , Cl − was relatively stronger than that of Na + and sulfate (SO 4 2− ). However, the effect of NH 4 + was relatively weaker at concentrations greater than 1.0 mmol L −1 . The presence of low concentrations of NO 3 − and NO 2 − promoted 2,4‐DNT reduction by Fe 0 and inhibited the reaction. The results suggest that 2,4‐DNT reduction by Fe 0 can be controlled by the ions composition of the waste‐water. Copyright © 2010 Society of Chemical Industry