Phosphate (PO43) is an anion of phosphorus compounds having phosphorus atom that is completed by four oxygen atoms located at the corner of the tetrahedron. Total phosphates can be measured directly by calorimeter or by the digestion process first before sample measurement.
There are 3 (three) types of phosphoric acid are known, namely: ortho phosphoric acid (H3PO4), acid pyrophosphate (H4P2O7) and meta phosphoric acid (HPO3). Ortho phosphoric is the most stable and most important (these substances are often called phosphate only), a solution of pyrophosphate and meta phosphate change to be ortho phosphoric slowly at ordinary temperatures, and faster to seethe. Ortho phosphoric acid is acid that has three alkalis which form three rows of salt such as primer ortho phosphoric (NaH3PO4), secondary ortho phosphoric (Na2HPO4) and tertiary ortho phosphoric (Na3PO4).
Each phosphate compounds present in dissolved form, suspended or bound in the cells of organisms in water. Phosphate compounds in waste water can be derived from the wastes of the population, industry and agriculture. In agricultural areas ortho phosphoric derived from fertilizer ingredients that go into the river via drainage (drain) and the flow of rain water.
Polyphosphate can enter rivers through the sewage of the population and industries that use materials such as detergents containing phosphate-laundering industry, metal industry and so on. Organic phosphate present in the sewage of the population (feces) and food scraps.
Organic phosphates can also occur of ortho phosphoric dissolved through biological processes due to both bacteria and plants to absorb phosphate for growth. The different types of phosphate are also used for the processing of anti-rust and anti-crust on heating water.