Lab 3

what are the nine parameters that test WQI

• temperature

• pH

• DO

• BOD (biochemical oxygen demand)

• total solids

• turbidity

• nitrate

• fecal california

• total phosphate

how to calculate water quality index score

• get Q value for each

• multiply each by weighing factor

• add added together

what is the least and most important parameter

• most: dissolved oxygen (0.17 weighing factor)

• least: total solids (0.07)

what are the ranges for WQI rating

• 100-90 is excellent

• 90-70 is good

• 70-50 is medium

• 50-25 is poor

• 0-25 is very poor

what is the difference between lotic and lentic sources

• lotic: flowing water

• lentic: still water

what is the difference between point source pollution and nonpoint source pollution

• point source: any contaminant that enters the environment from an easily identifiable and contained place

  • factories or sewage treatment plants

• non point source: from many general sources

  • runoff, precipitation, snow melting

how does temperature affect water

• even small degree changes can be signs of thermal pollution

• measured over a section of water not just one spot

• affects solubility of gases

  • more soluable in cold water

• increase in temperature also increases plant life

• the shallower the water, the more susceptiable to changes

what is thermal stratification

• recycling of nutrients in water

• in the summer, water is warm on top and cold underneath

  • separated by thermocline

• as fall comes, the top water cools, sinks and cycles with the water underneath

when is water the coldest and warmest

• warmest: late summer to early fall, late afternoon

• coldest: late winter to early spring, early morning

what is pH

• measure of OH and H ions in a solution

• a 1 pH change measures a ten fold increase or decrease in ion concentration

• algae bloom: more basic (higher pH)

what is dissolved oxygen

• concentration of dissolved oxygen in water

• caused by diffusion between air and surface of water, aeration as water flows over debris, churning of water bby waves and wind, photosynthesis

how do DO levels change throughout the day

• rise in the morning

• peak in the afternoon

• decrease at night

• algae bloom: higher DO

• algae die: low DO due to decomposition by bacteria

what is BOD

• the need for oxygen

• in running water, oxygen is replenished faster than it is used up

• in standing bodies, aerobic bacteria uses up more oxygen than can be made

how does matter affect BOD

• more dead material, more bacteria, hgiher BOD

hwo to test pH

• plug prob into the labquest

• invert the nalgene bottle to mix

• rinse the tip of the probe with distilled water and wipe off with a kim wipe

• place the tip into water and wait a couple minutes

• press play then stop

• go to analyze and then statistics and record the mean

how to record total solids

• measure each beaker

• add water

• place in oven

• after a week, measure the mass of the beaker with the solids

• subtract

how to measure turbidity

• connect the sensor to the labquest and allow to warm up for a minute

• uses macro plastic cuvettes

• label on side nearest to top NOT ON TOP

• fill with 3.5 mL using a serological pipette

• place the cuvette into the sensor

how to test DO

• plug DO probe into the labquest invert

• unscrew the protective case and rinse the tip with water

• switch the probe to % saturation

• submerge the probe and allow it to be submerged for a minute uses macro

• begin data collection and record the mean

how to test BOD

• get samples and record each DO in mg/mL

• after a week in a dark place, do the same again