EDTA

28 6
2009 11
ENV IRONMENTAL CHEM ISTRY
Vol. 28, No. 6
November 2009
EDTA 3
3 3
(, , , , 210093)
EDTA, , EDTA
; /EDTA 1000mgl - 1 :
120gl - 1 , 20gl - 1 , pH3, EDTA1mmoll - 1 . 60m in,
8917% , 5318%. EDTA
, pH, /EDTA
6315% , 1915%. , ,
/EDTA.
, EDTA, , .
,
[ 1 ] . ,
, , . ,
, , H 2 O 2 Fenton,
[ 2 ] , EDTAFe 2 + H 2 O [ 3 ]
2 . FeEDTA
H 2 O 2 , ,
, FentonpH > 4.
EDTA, EDTA
, GC /MS, /
EDTA, EDTA.
1
111
1000mgl - 1 , ,
pH, 1000mgl - 1 , ,
EDTA. /EDTA (40, 80, 120, 160,
200 mgl - 1 ) pH(1, 3, 5, 7) EDTA( 015, 1, 2, 4, 6 mmoll - 1 ) ,
, .
112
CODGB11914219891COD: A % = C t /C 0
COD;
C t COD).
100% (C 0
(756MC). 400 nm , ,
, : A % = C t /C 0
, 1000 mgl - 1 ;
C t ).
100% (C 0
pHpH; EDTA(, SPD210AVP) [ 4 ] .
GC /MS(, 9890N /5360): 10m l, H 2 SO 4
2009110.
3 (W TW ER0719). 3 3 , E2mail: chenzzg@ nju1edu1cn

784
28
pH2, 30m l3, 2m l, GC /MS. :
(30 m 0125m, 0125m) , 501m in, 8 m in - 1 3001m in,
1l. :
E I, 70 eV , 200 .
2
211EDTA
1000 mgl - 1 . ,
80 gl - 1 20 gl - 1 pH 3. :
EDTA , EDTA 2 mmoll - 1 , 1000
mgl - 1 , COD EDTA . 2 mmoll - 1 EDTA ,
EDTA.
1( a)( b), , COD , 80m in,
EDTA, COD8817%6715% , 5318%
2914%. Fe 2 + [ H ] , ,
EDTA, EDTA /Fe 2 + O 2 H 2 O 2 Fenton, ,
. , EDTA.
1 ( c)( d), EDTA
, , , EDTA.
, EDTA, , EDTA /Fe 2 +
O 2 H 2 O 2 , . , Noradoun [ 3 ] FeEDTA,
EDTA C 3 CO 2 CO , C 3
CO 2 CO35% , FentonEDTA
COD, COD.
1EDTA
( a) /EDTA ( b) /EDTACOD
( c) EDTA ( d) /EDTA
F ig11The effect of EDTA on the degradation of 42NP in m icro2electrolysis system

6 : EDTA 785
212/EDTA
21211/EDTA
20 gl - 1 , pH3, EDTA2 mmoll - 1 , 2
1000 mgl - 1 . 40 gl - 1 120
gl - 1 , 60m in, 6014%8419%. 200 gl - 1
, 7619%. 120 gl - 1 ,
, Fe 2 + EDTA, Fenton; ,
, H 2 O 2 [ 5 ] , H 2 O 2 , Fe 2 + ,
H 2 O 2 , OH, OHOH [ 6 ] .
21212pH/EDTA
120 gl - 1 20 gl - 1 , EDTA 2 mmoll - 1 ,
pHpH /EDTA 1000 mgl - 1 , 3
, pH3, /EDTA8419% , , pH
7, 6315% ,
5318% , pH71915%. , Fe 2 + ,
; /EDTA, EDTAFe 2 + , Fenton
, , EDTApH.
2
F ig12Influence of iron on 42NP degradation
3pH
F ig13Influence of pH on 42NP degradation
21213EDTA/EDTA
120 gl - 1 , 20 gl - 1 , pH3, 4EDTA
. EDTA1 mmoll - 1 , 8917% , EDTA
, . EDTA [ Fe ( EDTA ) (O 2 ) ] 2 - [ 3 ] ,
[ Fe ( EDTA) (O 2 ) ] 2 - H 2 O 2 , [ Fe ( EDTA ) (O 2 ) ] 2 - H 2 O 2
. , EDTA1mmoll - 1 .
4EDTA
F ig14Influence of EDTA concentration on 42NP degradation

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28
213/EDTA
/EDTAGC /MSHPLC,
. 5/EDTA
HPLC, , , , EDTA .
, /EDTA, 6.
[ H ] , , EDTAFenton,
OH, OH , OH
, .
5/EDTAHPLC
F ig15The HPLC of 42NP in m icro2electrolysis/EDTA system
6/EDTA
F ig16Proposed degradation pathway of 42NP in m icro2electrolysis/EDTA system
3
(1) EDTA, EDTA
, 5318% , /EDTA
8817%.
(2) EDTApH, 120 gl - 1 , 20 gl - 1 ,
pH7, EDTA2 mmoll - 1 , 6315% ;
1915%.
(3) EDTA : 120 gl - 1 , 20
gl - 1 , pH 3, EDTA1 mmoll - 1 , 60m in, 8917%.

6 : EDTA 787
[ 1 ] , , , 2, 42[ J ] 1, 2008, 27 (2) 186189
[ 2 ] , , , FentonFenton2, 42D[ J ] 1, 2005, 24 (4) 365369
[ 3 ] Noradoun C E, Cheng I F, EDTA Degradation Induced by Oxygen Activation in a Zero Valent Iron /A ir/W ater Systerm [ J ] 1Environ.
Sci. Technol. , 2005, 39 (18) 71587163
[ 4 ] Bergers P J M, Degroot A C, The Analysis of EDTA in W ater by HPLC [ J ] 1W ater Res. , 1994, 28 (3) 639642
[ 5 ] Kavitha V, Palanivelu K, Degradation of N itrophenols by Fenton and Photo2Fenton Processes [ J ] 1Chem istry, 2005, 170 8395
[ 6 ] Juliana C B, M ilton D C, Ladislau M N et al1, Oxidation Decomposition of A trazine by a Fenton2L ike Reaction in a H 2 O 2 /Ferrihydrite
System [ J ] 1W ater R esearch,
2007, 41 5562
THE EFFECT O F ED TA O N THE D EGRADAT IO N O F
42N ITRO PHENOL IN M ICRO 2EL ECTROLY S IS SY STEM
L I S ongL IU B oWANG Q iYAN D ong2dongWU W en2feiCHEN Ze2zhi
( Engineering Center of W ater Treatment and Environment Remediation, M inistry of Education, National Key Laboratory
of Pollution Control and Resource Reuse, School of the Environment of Nanjing University, Nanjing, 210093, China)
ABSTRACT
The main disadvantage of conventional m icro2electrolysis treatment is that the degradation efficiency is not
very high1 To solve this p roblem, the effect of EDTA enhancement on the degradation of 42NP in the
m icro2electrolysis/EDTA system was investigated, during which EDTA and 42NP was degraded by the
m icro2electrolysis system1 The results showed that EDTA could imp rove the removal rate of 42NP1 The
operating conditions for degradation of 42NP ( 1000 mgl - 1 ) in the m icro2electrolysis/EDTA system were
op tim ized by individual factor experiments and they were as following: C (Fe) = 120 gl - 1 , C (C) = 20 gl - 1 ,
C (EDTA) =1 mmoll - 1 , pH = 31 Under this condition, 42NP removal rates reached 8917% within 60 m in,
while the removal rate of 42NP was only achieved 5318% by the convention m icro2electrolysis treatment1 The
most deserves attention was that m icro2electrolysis/EDTA system also disp layed a reasonable good degradation
activity in a neutral condition. The removal of 42NP in m icro2electrolysis/EDTA system was over 6315% at
pH of 7, while it was only 1915% in m icro2electrolysis system1 The degradation p roducts of 42NP were
identified with GC /MS methods and the degradation pathways of 42NP were discussed1
Keywords: m icro2electrolysis, EDTA, effect, 42nitrophenol.