Emulsified oils (volatile, low molecular weight, and high molecular weight petroleum hydrocarbons as well as food based oils) and polycyclic aromatic hydrocarbons (PAHs)

Poorly settling solids such as silt, clay, cement, wood extractives, poorly soluble organics, microorganisms, and contaminants that add turbidity to water

Contaminants such as ammonia, cyanide, sulphide, arsenic, and iron that react with oxygen

Negatively charged metals such as arsenic, molybdenum, chromium, and phosphate that form co-precipitates with iron or aluminum

Positively charged heavy metals such as copper, cadmium, nickel, lead, and zinc that form insoluble hydroxides