Solubility is not to be confused with the ability to 'dissolve' a substance, because the solution might also occur because of a chemical reaction. For example, zinc 'dissolves' (with effervescence) in hydrochloric acid as a result of a chemical reaction releasing hydrogen gas in a displacement reaction.
All three kidney, liver and lungs purify the blood. The lungs help remove carbon dioxide, the kidneys remove water-soluble waste and the liver removes fat soluble wastes and many other impurities from the blood....ref:http://www.pharmainfo.net/answers/pharmaquestion/which-organ-purifies-blood.
Red blood cells are released from the spleen into blood circulation to help compensate for blood loss. The spleen is a lymphatic organ that performs the valuable function of filtering blood. While it is an important organ, it can be removed when necessary without causing death. This is the case because other organs, such as the liver and bone marrow, can perform filtration functions in the body.