CEE 370 Environmental Engineering Principles Lecture #25 Water - PDF document

CEE 370 Lecture #25 11/6/2019 Print version Updated: 6 November 2019 CEE 370 Environmental Engineering Principles Lecture #25 Water Quality Management III: Lakes & toxic models Reading: Mihelcic & Zimmerman, Chapter 7 & 3.10 Reading: Davis & Cornwall, Chapt 5-4 Reading: Davis & Masten, Chapter 5-6 & 9-4 David Reckhow CEE 370 L#25 1 Lake Pollution  Percent impaired by pollutant  Percent impaired by sources From Masters, section 5.4 2 CEE 370 L#25 David Reckhow Lecture #25 Dave Reckhow 1

CEE 370 Lecture #25 11/6/2019 Lake life cycle  Succession in lakes  Oligotrophic  Mesotrophic  Eutrophic  Other  Dystrophic  Hyper- eutrophic 3 CEE 370 L#25 David Reckhow Lake Eutrophication  As lakes age, they become more productive  Natural processes: natural Eutrophication  Pollutant loading: cultural Eutrophication  Limiting nutrient  Liebig’s law of minimum  Redfield Ratio  C:N:P in most phytoplankton is 106:16:1  When P<16*N, it limit’s growth 4 CEE 370 L#25 David Reckhow Lecture #25 Dave Reckhow 2

CEE 370 Lecture #25 11/6/2019 Nutrient loading and Eutrophication 5 CEE 370 L#25 David Reckhow Estrogen lake study 6 CEE 370 L#25 David Reckhow Lecture #25 Dave Reckhow 3

CEE 370 Lecture #25 11/6/2019 Concern over drinking water  Drugs? CEE 370 L#25 7 David Reckhow Organic Compounds: Types? Pharmaceuticals, etc Natural Compounds   Anti-epileptics  Fulvics  Beta-blockers  Proteins, carbohydrates, etc  Domestic WW Organics X-ray contrast media   Industrial Synthetic Organics antibiotics    Plasticizers: phthalates Home & Personal Care Products   solvents: tetrachloroethylene triclosan   waxes: chlorinated parafins Musks, flame retardants   others: PCB’s Endocrine Disrupters  Hydrocarbons & oil derivatives Steroidal estrogens    includes products of combustion: Natural process byproducts  PAH’s Conjugated pharmaceuticals  Agricultural Chemicals  Engineered process byproducts   pesticides: DDT, kepone, mirex disinfection byproducts, etc  8 CEE 370 L#25 David Reckhow Lecture #25 Dave Reckhow 4

CEE 370 Lecture #25 11/6/2019 Pollutant loss in lakes  Photolysis  Destruction by solar light energy  Biodegradation  Metabolism by microorganism  Hydrolysis  Chemical decomposition  Volatilization  Loss to the atmosphere  Adsorption and settling  Loss to particles that end up buried in sediments 9 CEE 370 L#25 David Reckhow Photolysis  Chemical breakdown initiated by light energy  two types  direct photolysis  sensitized (or indirect) photolysis  Several steps  some solar light reaches water surface  some of this light penetrates to the solute  some of this is absorbed by the solute  some of absorbed light is capable of causing a reaction 10 CEE 370 L#25 David Reckhow Lecture #25 Dave Reckhow 5

CEE 370 Lecture #25 11/6/2019 Solar Radiation 11 CEE 370 L#25 David Reckhow Susceptible bonds? 12 CEE 370 L#25 David Reckhow Lecture #25 Dave Reckhow 6

CEE 370 Lecture #25 11/6/2019 Biotransformation  Microbially mediated transformation of organic and inorganic contaminants  Biochemical processes:  Metabolism: toxicant is used for synthesis or energy  Cometabolism: not “used”, but transformed anyway  Chemical Effects:  Detoxication: Toxic to Non-toxic  mineralization  Activation: Non-toxic to Toxic 13 CEE 370 L#25 David Reckhow Refer to lecture #17 Bio kinetics  X  Michaelis-Menten equation:  k max   m  Y k c  µ max = maximum growth rate (yr -1 ) s  X=microbial biomass (#cells/m 3 )  Y= yield coefficient (cells produced per mass toxicant removed, #cells/µg)  k s = half-saturation constant (µg/m 3 )  k b = rate of biotransformation (yr -1 )  If c<<k s , then:   X  k max k X m m 2 Yk s 14 CEE 370 L#25 David Reckhow Lecture #25 Dave Reckhow 7

CEE 370 Lecture #25 11/6/2019 Bio kinetics (cont.)  Wide environmental range  phenol: k m =4.0 d -1 OH  diazinon: k m =0.016 d -1 C 2 H 5 S O CH 3 P O N CH O CH 3  Temperature correction C 2 H 5 N   =1.04-1.095 CH 3        T 20 k k m m T 20 15 CEE 370 L#25 David Reckhow Hydrolysis  Reaction with water and its constituents  H 2 O k  k h  n     OH - k k OH h b     H +  k k H h a     Autodissociation    K w OH H      Combining:      k k OH k k H h b n a  or: K     pH k k w k k 10 h b  n a pH 10 16 CEE 370 L#25 David Reckhow Lecture #25 Dave Reckhow 8

CEE 370 Lecture #25 11/6/2019 Volatilization: The two film theory p g p i Interface c i c 17 CEE 370 L#25 David Reckhow Two film model  Flux from the bulk liquid to the interface   J K ( c c ) l l i  Flux from the interface ot the bulk gas K Mass transfer g   J ( p p ) g RT g i velocities (m/d) a  And the K’s are related to the molecular diffusion coefficients by: D D  l g K  K l z g z l g 18 CEE 370 L#25 David Reckhow Lecture #25 Dave Reckhow 9

CEE 370 Lecture #25 11/6/2019 Whitman’s 2 film model (cont.)  According to Henry’s law:  p H c i e i  And relating this back to the bulk concentration   J     p H l c   i e K   l  now solving and equating the fluxes, we get: 1 1 RT   a v K H K The net transfer v l e g velocity across the air- water interface (m/d) 19 CEE 370 L#25 David Reckhow Whitman’s 2 film model (cont.) H  Which can be  v K e v l   K  rewritten as: H RT   l K e a   g  Now, applying it to Contaminant Environment specific specific toxicants  p g  0  And converting to the v appropriate units: v  k v H 20 CEE 370 L#25 David Reckhow Lecture #25 Dave Reckhow 10

CEE 370 Lecture #25 11/6/2019 Volatilization: Parameter estimation  Liquid film mass transfer coefficient (d -1 ) Compound 0 . 25  32   K K   molecular l l , O  M  2 weight  Gas film mass transfer coefficient (d -1 ) 0 . 25  18   K 168 U   g W  M  Wind velocity (mps) 21 CEE 370 L#25 David Reckhow Toxics Model: CSTR with sediments  Internal Transport Processes (between compartments)  dissolved: diffusion  particulate: settling, resuspension & burial  Expressed as velocities (e.g., m/yr) Water (1) Settling (v s ) Resuspension (v r ) Diffusion (v d ) Mixed Sediments (2) Burial (v b ) Deep Sediments (3) 22 CEE 370 L#25 David Reckhow Lecture #25 Dave Reckhow 11

CEE 370 Lecture #25 11/6/2019 Functionally identical to M&Z equ# 3.32 Sorption 𝐿 � 𝑟 𝐷 C  Linear Isotherm K  particulat e C dissolved '   c c d p See M&Z, M s k ad section 3.10 Particle k de  K     k v s s   1 K  Particle can then settle v s 23 CEE 370 L#25 David Reckhow Also in Lecture #16 biomagnification & Lecture #22 on groundwater retardation Octanol:water partitioning  2 liquid phases in a separatory funnel that don’t mix  octanol  water  Add contaminant to flask  Shake and allow contaminant to reach equilibrium between the two  Measure concentration in each (K ow is the ratio)  Correlate to environmental K K  fn ( K ) ow 24 CEE 370 L#25 David Reckhow Lecture #25 Dave Reckhow 12

CEE 370 Lecture #25 11/6/2019 From Lecture #16 Bioaccumulation  Mercury in food chain  Data from Onondaga Lake Biomass Concentration (box size) (Shading) 25 CEE 370 L#25 David Reckhow From Lecture #16 Lab to Field  Octanol water partition coefficients and bioconcentration factors 26 CEE 370 L#25 David Reckhow Lecture #25 Dave Reckhow 13

CEE 370 Lecture #25 11/6/2019 Completely-mixed lake or CMFR  Often useful to assume perfect mixing  same concentration throughout system     Accumulation loading outflow reaction settling Outflow C C Loading Q C in reaction Q V settling 27 CEE 370 L#25 David Reckhow Other Terms in the Mass Balance  Outflow  Outflow Qc  Reaction   Re action kM kVc  Settling J=vc  Settling vA c s A s  k Vc s Sediment- Note HW#6, water interface problem 2  v H V A H s  k Since: s 28 CEE 370 L#25 David Reckhow Lecture #25 Dave Reckhow 14