Difference between co precipitation and post precipitation?

Answer 1

In chemistry, coprecipitation (CPT) or co-precipitation is the carrying down by a precipitate of substances normally soluble under the conditions employed.[1] Analogously, in medicine, coprecipitation is specifically the precipitation of an unbound "antigen along with an antigen-antibody comple

There are three main mechanisms of coprecipitation: inclusion, occlusion, and adsorption.[3] An inclusion occurs when the impurity occupies a lattice site in the crystal structure of the carrier, resulting in a crystallographic defect; this can happen when the ionic radius and charge of the impurity are similar to those of the carrier. An adsorbate is an impurity that is weakly bound (adsorbed) to the surface of the precipitate. An occlusion occurs when an adsorbed impurity gets physically trapped inside the crystal as it grows.

Besides its applications in chemical analysis and in radiochemistry, coprecipitation is also "potentially important to many environmental issues closely related to water resources, including acid mine drainage, radionuclide migration in fouled waste repositories, metal contaminant transport at industrial and defense sites, metal concentrations in aquatic systems, and wastewater treatment technology"[4].

Coprecipitation is also used as a method of magnetic nanoparticle synthesis.[5]

Answer 2

Co-precipitation occurs when an impurity is incorporated into the precipitate during the initial precipitation process, while post-precipitation refers to a separate precipitation process that occurs after the initial precipitation is complete. Co-precipitation is often unintentional and can lead to impurity incorporation, whereas post-precipitation can be a deliberate step to further purify the precipitate or isolate specific components.