| 摘要 |
Acids contaminated with multi-valent metal salts are purified by a process which involves treatment in an acid sorption unit (ASU) and a nanofiltration unit (NFU). The feed solution can first be delivered to the ASU, which produces two solutions, one high in acid concentration and the other high in metal salt concentration. The high acid concentration solution can be treated in the NFU to produce an acid end product and a reject metal salt solution which can be recirculated to the feed of the NFU. Alternatively, the high metal salt solution can be treated in the NFU, and its permeate recirculated to the ASU as eluate. In an alternative configuration, the feed is delivered first to the NFU. In all cases, the membrane reject solution from the NFU is recirculated to increase the metal salt concentration. A second NFU can be used to process the solution from the ASU which contains a high metal salt concentration. |
