CEE 697K ENVIRONMENTAL REACTION KINETICS. HAAs: Chlorine vs Chloramine

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1 Updated: 13 November Print version CEE 697K ENVIRONMENTAL REACTION KINETICS Lecture #17 Kinetic Modeling: Computer Models Case Study: Chloramination II Brezonik, pp. Introduction HAAs: Chlorine vs Chloramine Dihalo products, but little trihalo NOM Oxidation & Substitution (chlorine & chloramines) O O O O R'' C CCl C R' R'' C CCl C OH Hydrolysis Hydrolysis O Hydrolysis & Oxidation O R'' C CHCl Slow Cl HC C OH DCAA Substitution (free chlorine only) O R'' C CCl 3 Hydrolysis THM CHCl 3 Oxidative Hydrolysis O Cl 3 C C OH David TCAA A. Reckhow 1

2 hr. chlorination 4 hr. chlorination plus 48 hr. chloramination +1% +14% 3 THM Concentration (ug/l) % +18% +47% +6% +33% +36% +3% THMs: Chlorination followed by Chloramination The UMass- MWRA Study 0 ph 6, temp=c, 1.5 mg/l Cl ph 6, temp=c, 3.5 mg/l Cl ph 6, temp=0c, 1.5 mg/l Cl ph 6, temp=0c, 3.5 mg/l Cl ph 8, temp=c, 1.5 mg/l Cl ph 8, temp=c, 3.5 mg/l Cl ph 8, temp=0c, 1.5 mg/l Cl ph 8, temp=0c, 3.5 mg/l Cl ph 7.6, temp=0c, 3.5 mg/l Cl 1.5 mg/l PO hr. chlorination 4 hr. chlorination plus 48 hr. chloramination 4 HAA Concentration (ug/l) % +4% +14% +6% +31% +0% +9% +0% 10 HAAs: Chlorination followed by Chloramination The UMass- MWRA Study 0 ph 6, temp=c, 1.5 mg/l Cl ph 6, temp=c, 3.5 mg/l Cl ph 6, temp=0c, 1.5 mg/l Cl ph6, temp=0c, 3.5 mg/l Cl ph 8, temp=c, 1.5 mg/l Cl ph 8, temp=c, 3.5 mg/l Cl ph 8, temp=0c, 1.5 mg/l Cl ph 8, temp=0c, 3.5 mg/l Cl ph 7.6, temp=0c, 3.5 mg/l Cl 1.5 mg/l PO 4

3 Precursors & Behavior Mono & Dihalo- DBPs Trihalo-DBPs Precursor Origins Coag. or Oxidation Haloacids (DCAA) THMs General NOM Average Average Aldehydes Ketones (Dichloropropanone) Aldehydes (Chloral Hydrate) Ketones (Trichloropropanone) Oxidized NOM (bacterial, solar, ozone) Poor Good Nitroalkanes Nitriles (Dichloroacetonitrile) Amides (Dichloroacetamide) Cyanogen Halides (CNCl, CNBr) Nitroalkanes (Chloropicrin) Nitriles (Trichloroacetonitrile) Amides (Trichloroacetamide) reactive Nitrogen species Algal (autochthonous) General Trends Average Halobenzoquinones? Haloacids (TCAA) Terrestrial - Lignin (allochthonous) Good Preferentially formed by Chloramination 5 Removal by: Average Poor DBP control with DS management 6 Driven by Regulations THM Biodregradation Parameter Tri- HAAs Di- HAAs HANs TCP DCP CP Iodo- DBPs Time Cl ~ Dose ph ~ Cl to ~ ~ ~ NH Cl Temp ~ Notes: HANs: haloacetontriles, including DCAN TCP: trichloropropanone, a haloketone DCP: dichloropropanone: a haloketone CP: chloropicrin: a halonitromethane Iodo-DBPs: include CEE697K iodinated Lecture THMs, #17 HAAs, etc 3

4 Chloramines vs Free Chlorine 7 DBPs Lower levels of trihalogenated byproducts Easier to meet current DBP regulations Less impact on dihalogenated compound Some are higher with chloramines More of some types of N-DBPs Organic chloramines, nitriles, amides, nitro compds Other concerns Growth of ammonia oxidizing bacteria Loss of residual, formation of reactive intermediates Reduction of Lead (IV) Public perception & direct health effects Theoretical Breakpoint Curve 8 8 Chlorine Residual mg Cl /mg NH 4 -N NHCl HOCl + OCl - NH Cl NCl Chlorine Dose, mg Cl /mg NH 4 -N 4

Distribution Diagram for Chloramine Species with ph 9 100 Total Combined Chlorine (%) 80 60 40 0 Monochloramine Dichloramine Nitrogen Trichloride 3 5 6 7 8 ph Jafvert &

5 Distribution Diagram for Chloramine Species with ph Total Combined Chlorine (%) Monochloramine Dichloramine Nitrogen Trichloride ph Jafvert & Valentine Model 10 Jafvert, C. T. and R. L. Valentine (199). "Reaction Scheme for the Chlorination of Ammoniacal Water." Environmental Science & Technology 6(3):

6 Model Equations Vikesland, P. J., K. Ozekin, et al. (001). "Monochloramine decay in model and distribution system waters." Water Research 35(7): # Reaction Rate coefficient/equilibrium References constant (5 C) 1.1 HOCl+NH 3 NH Cl+H O k 1.1 = M 1 h 1 Morris and Isaac (1981) 1. NH Cl+H O HOCl+NH 3 k 1. = h 1 Morris and Isaac (1981) 1.3 HOCl+NH Cl NHCl +H O k 1.3 = M 1 h 1 Margerum et al. (1978) 1.4 NHCl +H O HOCl+NH Cl k 1.4 = h 1 Margerum et al. (1978) 1.5 NH Cl+NH Cl NHCl +NH 3 k d a Vikesland et al. (001) 1.6 NHCl +NH 3 NH Cl+NH Cl k 1.6 = M h 1 Hand and Margerum (1983) 1.7 NHCl +H O I k 1.7 = M 1 h 1 Jafvert and Valentine (1987) 1.8 I+NHCl HOCl+products k 1.8 = M 1 h 1 Leao (1981) 1.9 I+NH Cl products k 1.9 = M 1 h 1 Leao (1981) 1.10 NH Cl+NHCl products k 1.10 =55.0 M 1 h 1 Leao (1981) 1.11 HOCl H++OCl pk a =7.5 Snoeyink and Jenkins (1980) 1.1 NH 4+ NH 3 +H + pk a =9.3 Snoeyink and Jenkins (1980) 1.13 H CO 3 HCO 3 +H + pk a =6.3 Snoeyink and Jenkins (1980) 1.14 HCO 3 CO 3 +H + pk a =10.3 Snoeyink and Jenkins (1980) Vikesland modification 1 Modified version of equation #5 for carbonate k d =k H+ [H + ]+k HCO3 [H CO 3 ]+k HCO3 [HCO 3 ] Where k H+ =.5 x 10 7 M - h -1 k HCO3 = 4 x 10 4 M - h -1 k HCO3 = 800 M - h -1 I is the unidentified monochloramine auto-decomposition intermediate Vikesland, P. J., K. Ozekin, et al. (001). "Monochloramine decay in model and distribution system waters." Water Research 35(7):

7 Temperature Effects 13 Reaction Rate coefficient/equilibrium constant References HOCl+NH 3 NH Cl+H O k 1.1 = exp( 1510/T) M 1 h 1 Morris and Isaac (1981) NH Cl+H O HOCl+NH 3 k 1. = exp( 8800/T) h 1 Morris and Isaac (1981) HOCl+NH Cl NHCl +H O k 1.3 = exp( 010/T) M 1 h 1 Margerumet al.(1978) NH Cl+NH Cl NHCl +NH 3 k 1.5 =kh + [H + ]+khco 3 [HCO 3 ]+kh CO 3 [H CO 3 ] k H+ = exp( 169/T) M h 1 Granstrom (1954) k HCO3 = exp( 144/T) M h 1 Vikesland et al. (001) k HCO3 = exp( 406/T) M h 1 Vikesland et al. (001) H CO 3 HCO 3 +H + pka= (T) (T)+1. Snoeyink and Jenkins (1980) HCO 3 H ++CO 3 pka= (T) (T)+3.6 Snoeyink and Jenkins (1980) NH 4 + NH 3 +H + pka= (T) (T)+7.6 Bates and Pinching (1950) HOCl OCl +H + pk a = (T) (T)+0.5 Chloramine Decay 14 NH 3 1 / NO 3 - H O HCl + 1 / H + HOCl NH Cl H O NHCl NH 3 H O HCl NOH H O + HCl HOCl + HCl N H O HOCl + 3HCl H O NCl 3 7

8 Valentine Model #1 15 Chloramine Formation and Decay pathway HOCl H O NH 3 k k 1 HOCl H Equilibrium NH Cl NH Cl k d k 3 HOCl Rate Limiting Step NH 3 H O NH Cl NHCl Fast 3Cl -, 3H + N Valentine Model # 16 Looking at the Rate Limiting Step d NH Cl 3k dt NH ClNH Cl k NH ClHOCl d 3 NH Cl NH Cl NH Cl HOCl NH Cl HOCl k d k 3 k d k 3 NH 3 H O NH 3 H O NH Cl NHCl NH Cl NHCl 3Cl -, 3H + N 3Cl -, 3H + N 8

9 Valentine Model #3 17 Re-arranging: d NH Cl 3k dt d d NH Cl 3k dt NH ClNH Cl k NH ClHOCl d 3 NH Cl k NH ClHOCl d 3 NH Cl HOCl 3k d k3 NH Cl dt NH Cl Valentine Model #4 18 Looking at the first step Forward reaction rate equals reverse rate equilibrium 1 HOCl NH3 k NH Which leads to Cl k k HOCl k1 NH Cl NH 3 HOCl H O NH 3 k k 1 NH Cl HOCl H O 9

10 Valentine Model #5 19 Combining dnh Cl HOCl 3k d k3 NH Cl dt NH Cl We get: k HOCl k1 NH Cl NH 3 d NH Cl dt k k 3 k1 3kd Cl NH3 NH 0 ph effects Ammonia and chloramine species are prone to protonation Dichloramine is more prevalent at low ph Why? The protonated form of monochloramine reacts more quickly than the neutral form or the reverse reaction is slower NH 3Cl NH NH Cl NHCl 4 10

Nitrogen Trichloride 1 Acute Human toxicity?? Drinking Water, showers and swimming pools Blatchley s group: Weng, S.C., W.A. Weaver, M.Z. Afifi, T.N. Blatchley, J.S. Cramer, J. Chen, and E.R.

11 Nitrogen Trichloride 1 Acute Human toxicity?? Drinking Water, showers and swimming pools Blatchley s group: Weng, S.C., W.A. Weaver, M.Z. Afifi, T.N. Blatchley, J.S. Cramer, J. Chen, and E.R. Blatchley Dynamics of gas-phase trichloramine (NCl(3)) in chlorinated, indoor swimming pool facilities. Indoor Air 1: Trichloramine (NCl 3 ), which is often associated with the chlorine odor of swimming pools, has been identified as a common by-product of chlorination of many organic-n compounds that are common to swimming pools, including urea, creatinine, and amino acids. NCl 3 is a respiratory irritant to mice, and more recent studies have indicated NCl 3 to contribute to acute ocular and respiratory irritation symptoms in lifeguards and swimming pool workers. Retrospective studies have shown positive correlation between irritation symptoms among swimmers and patrons and high gas-phase NCl 3 concentration at indoor pool facilities. Measuring chloramines DPD titrimetric method C H 5 C H 5 C H 5 C H 5 N N HOCl HO, HCl I3- I-, HI N N Colorless H H Fe(+III) H Fe(+II), H+ Red 11

12 Oxidation of DPD 3 Reaction with free chlorine or iodine From Gordon et al., 1987 Red David A. Reckhow Speciation with DPD 4 FRC Direct reaction of HOCl/OCl - with DPD Monochloramine Oxidation of I - to I 3- by NH Cl, and subsequent oxidation of DPD Require only a small amount of iodide Dichloramine Oxidation of I - to I 3- by NHCl, and subsequent oxidation of DPD Require a large amount of iodide and longer reaction time David A. Reckhow 1

13 DPD titrimetric method 5 C H 5 C H 5 C H 5 C H 5 N N HOCl HO, HCl I3- I-, HI N N Colorless H H Fe(+III) H Fe(+II), H+ Red David A. Reckhow DPD titrimetric method 6 ph control Low ph leads to protonated forms High ph catalyzes DPD oxidation by atmospheric oxygen Potential interference Any substance that can directly oxidize DPD MCA can do this a bit, so we sometimes add HgCl Any substance that can oxidize iodide Hydrogen peroxide, persulfate David A. Reckhow 13

14 Figure 1 Schematic representation of the MIMS system (a) and configuration of the membrane cell (b). 7 Published in: Chii Shang; Ernest R. Blatchley; Environ. Sci. Technol. 1999, 33, DOI: /es Copyright 1999 American Chemical Society Figure Representative EI mass spectra (35 m/z 15) of: (a) free chlorine (000 mg/l as Cl), (b) monochloramine (40 mg/l as Cl), (c) dichloramine (0 mg/l as Cl), and (d) trichloramine (0 mg/l as Cl). 8 Published in: Chii Shang; Ernest R. Blatchley; Environ. Sci. Technol. 1999, 33, DOI: /es Copyright 1999 American Chemical Society 14

15 Figure 3 Effects of membrane temperature and liquid flow rate on the MIMS system performance (dichloramine at 9. and 8.5 mg/l as Cl, respectively):, signal abundance;, signal response time;, signal noise. 9 Published in: Chii Shang; Ernest R. Blatchley; Environ. Sci. Technol. 1999, 33, DOI: /es Copyright 1999 American Chemical Society Figure 4 (a) Quantification of monochloramine by the MIMS method at m/z = 53: concentrations refer to titrimetrically determined values (as Cl) up to the limit of detection (see insert). (b) Linear response curves of the MIMS method for chloramines:, monochloramine (m/z = 53);, dichloramine (m/z = 87);, trichloramine (m/z = 119). 30 Published in: Chii Shang; Ernest R. Blatchley; Environ. Sci. Technol. 1999, 33, DOI: /es Copyright 1999 American Chemical Society 15

16 Figure 5 Residual chlorine concentrations as a function of Cl:N mass ratio after 30 min chlorination of an aqueous solution containing (a) ammonia and (b) glycine (0.5 mg/l as N) at ph 7. For each Cl:N ratio, residual chlorine was measured by DPD/FAS titration (left bar) and MIMS/EI (right bar). 31 Published in: Chii Shang; Ernest R. Blatchley; Environ. Sci. Technol. 1999, 33, DOI: /es Copyright 1999 American Chemical Society 3 Chlorine dose DPD MIMS Lafayette wastewater (NH 4+ -N, 1. mg/l; org-n, 13.1 mg/l) species mean RSD b (%) mean RSD b (%) DPD MIMS DPD 1.0 free Purdue p otable wa ter (NH 4+ - N, 0.05 m g/l; org- N, 0.35 m g/l) mono (n = 6) di (n = 6) 0.03 (n = 6) tri free (n = 6) (n = 6) mono (n = 6) di 0.40 (n = 6) 0. 1 (n = 6) tri free.9 (n = 3).58 1 (n = 3) mono (n = 3) (n = 3) di (n = 3) (n = 3) tri (n = 3)

17 33 DPD MIMS Lafayette wastewater (NH 4+ - N, 1. mg/l; org- N, 13.1 mg/l) Purdue potable water (NH 4+ -N, 0.05 mg/l; org-n, 0.35 mg/l) chlorine species mean RSD b (%) mean RSD b (%) DPD MIMS DPD MIMS dose 1.0 free mono (n = 6) di (n = 6) 0.03 (n = 6) tri free (n = 6) (n = 6) mono (n = 6) di 0.40 (n = 6) 0. 1 (n = 6) tri free.9 (n = 3).58 1 (n = 3) mono (n = 3) (n = 3) di (n = 3) CEE697K 0.37 Lecture 0 (n#17 = 3) David A Reckhow 34 DPD based method for NCl 3 Schematic of impinger method for gas-phase NCl 3 measurement. The arrows indicate the air flow pattern Validation experiment setup. A gaswashing bottle containing an aqueous solution of the target compound was prepared and connected to the air entrance of measuring impinger system Weng, S.C., W.A. Weaver, M.Z. Afifi, T.N. Blatchley, J.S. Cramer, J. Chen, and E.R. Blatchley Dynamics of gas-phase trichloramine CEE697K (NCl(3)) Lecture in #17 chlorinated, indoor swimming pool facilities. Indoor Air 1:

35 Compound Typical liquidphase concentration (mg/l) a Henry s law constant (atm, 0 C) b Equilibrium gasphase Concentration (mg/m 3 ) Reported gasphase concentration at pool area (mg/m 3 ) HOCl c 1.

18 35 Compound Typical liquidphase concentration (mg/l) a Henry s law constant (atm, 0 C) b Equilibrium gasphase Concentration (mg/m 3 ) Reported gasphase concentration at pool area (mg/m 3 ) HOCl c N.A Cl c N.A NH Cl N.A NHCl N.A NCl d CHCl e CHBr Cl e CHBr e CNCl N.A CNCHCl N.A CH 3 NCl f 36 Dynamics of gas phase trichloramine (NCl3) in chlorinated, indoor swimming pool facilities Indoor Air Volume 1, Issue 5, pages , 14 MAR 011 DOI: CEE697K /j x Lecture #

37 Dynamics of gas phase trichloramine (NCl3) in chlorinated, indoor swimming pool facilities Indoor Air Volume 1, Issue 5, pages 391-399, 14 MAR 011 DOI: CEE697K 10.1111/j.1600-0668.011.00710.

19 37 Dynamics of gas phase trichloramine (NCl3) in chlorinated, indoor swimming pool facilities Indoor Air Volume 1, Issue 5, pages , 14 MAR 011 DOI: CEE697K /j x Lecture #17 Dynamics of gas phase 38 trichloramine (NCl3) in chlorinated, indoor swimming pool facilities Indoor Air Volume 1, Issue 5, pages , 14 MAR 011 DOI: CEE697K /j x Lecture #

20 Liquid vs gas concentration 39 Relationship between DPD-based liquid-phase NCl 3 concentration and gas-phase NCl 3 concentration in Pool A facility. The results showed no significant correlation between these two parameters for this facility. The correlation coefficients between liquid-phase and gas-phase NCl 3 concentrations were and for the diving well and competition pool, respectively. Gas-phase NCl 3 Concentration (mg/m 3 as Cl ) Diving Well Competition Pool Liquid-phase NCl 3 Concentration (mg/l as Cl ) Loss in Tedlar bag 40 Comparison of gas-phase NCl 3 measurement at pool deck and in the laboratory with a Tedlar gas-sampling bag. The results showed apparent loss of NCl 3 from the gas-sampling bag during transport Gas-phase NCl 3 Concentration (mg/m 3 as Cl ) Glassware on Pool Deck Gas Sampling Bag 0.0 6/8 6/ 7/6 7/0 8/3 Time 0

21 41 To next lecture 1

DBP Control: Chloramine Chemistry. Chris Griffin Hach Company

DBP Control: Chloramine Chemistry Chris Griffin Hach Company 1 BEFORE WE BEGIN 2 Who currently Uses Chlorine only? Before we begin. Uses Chloramination at their water plant or in distribution? Uses Chloramination