Nutrients

Why monitor nutrients?– Plant and algae growth

Carbon, nitrogen, phosphorus, oxygen, silica, magnesium, potassium, calcium, iron, zinc, and copper

– Health concerns Reproductive problems Methemoglobinemia in infants

– Global warming Ozone depletion

Nutrients

Eutrophication– High nutrient concentrations stimulate

excessive algal blooms

Nutrients

Phytoplankton blooms– Could cause decrease of SAV– Harmful

Hypoxic

Anoxic

Nutrient Sources

Natural Sources1. Freshwater running over geologic

formations

2. Decomposing organic matter

3. Extraction from the atmosphere

Nutrient Sources

Anthropogenic Sources1. Atmospheric deposition

2. Surface water

3. Groundwater

Nutrient Levels

Water & Wastewater samples– Milligrams per liter

mg/L

– Micrograms per liter μg/L

Air, soils, sludges, & semisolids– Parts per million

ppm

– Parts per billion ppb

Nutrient Levels

Safe Water Drinking Act– Passed in 1974– Maximum Contaminant Levels– National Primary Drinking Water

Regulations

The Different Forms of Nutrients

Determined by environmental conditions

Nitrogen:– Nitrate NO3

-

– Nitrite NO2-

– NO– NO2

– Ammonium NH4+

– Ammonia NH3

– Urea Organic form

NOx

Forms of Phosphorus Phosphorus occurs naturally in rocks

– Weathering releases phosphate ions (PO4

-3)

Inorganic– Orthophosphates– Polyphosphates (Metaphosphates)

Organic phosphate

Forms of Phosphorus Orthophosphates

– Readily available to the biological community

– Typically found in low concentrations in unpolluted waters

H3PO4

H2PO4-

HPO42-

PO43-

Forms of Phosphorus Organic

– Phosphate bound or tied up in plant tissue, waste solids, or other organic material

– When decomposed thru bacterial action, phosphate released and returned to environment

Silica in Water Silicon dioxide

– SiO2 + 2H2O H4SiO4

H4SiO4 (monosilicic acid)

– Three forms:

1. Reactive

2. Colloidal

3. Suspended particles

The Nitrogen Cycle

Phosphate Cycle

Inputs: Riverine = 80% Aeolian

deposition = 7% Dissolution of

seafloor basalts = 7%

Hydrothermal vents = 6%

Turbidity Measure of relative

sample clarity

How much light is scattered by suspended particles

Turbidity Measurements Slow-moving, deep

waters– Secchi disk– Rule of Thumb: light

penetrates 2-3x Secchi depth

Turbidity Measurements Fast-moving,

shallow water– Turbidimeter

(Nephelometer)

– Nephelometric Turbidity Units (NTU’s)

NC Waters Average NTU’s

– Salt ~ 25 – Fresh ~ 50

http://h2o.enr.state.nc.us/

Factors Affecting Turbidity

1. High Flow Rate

2. Soil Erosion

3. Urban Runoff

4. Wastewater & Septic System Effluent

5. Decaying plants & animals

6. Bottom feeding fish

7. Algal blooms

8. Flooding

Sediment AnalysisOgeechee Corer

Sediment Analysis