Units and Measurement  Units of concentration ppmM (for solids and Liquids) ppmV (For gases, consider Temp & Pressure) difference between mg/L and ppm Molarity Molality Normality (Concept of Equvalent weight)  Acid and Bases (pH = -Log 10 [H + ] Weak acid (less than 100% dissociation) Strong Acids (100% dissociation) Buffers

Mass Balance Batch Reactor CSTR First Order Kinetics Zero Order Kinetics

Dissolution of gases in Water  Henrys Law: X A = K H p A – Important to remember: X A is mole fraction of gas in water

Toxicity & Dose Response Mutagen Teratogen attacks Germ Cel Carcinogen (attacks Somatic Cells) Transmissible to Progeny Lead to Cancer (not death necessarily)

Methods to Test Toxicity  Epidermiologic Data Analysis  From past incidences Love Canal, Kippon Disaster, Chernobile, Bhopal  Controlled Animal Testing  Use of bacteria to Chipms Controlled Human Studies  Doctors office (the free Treatment)

Dose Response Curve Points to Remember Carcinogen: No Threshold LD 50 : 50% of subject dies

How to Calculate Cancer Risk Risk = CDI * Potency factor CDI: Chronic Daily Dose CDI=

Water Quality  Soilds Total dissolved solids Suspended Solids Volatile Suspended Soilds  Liquid Hardness Alkalinity BOD, BODu, BOD5, BODt

More on Water Quality ThoD: Theoretical Oxygen Demand BOD t =BOD u (1-e -k 1 t ) Temperature Dependence of BOD K T =K 20  (T-20)

Steeter Phelps Equation  How to find critical DO and the distance when it happens