Abstract: A combined membrane/sorption process is used to selectively remove ions from liquid streams. As an example, nitrate ions can be more effectively removed from an aqueous stream also containing sulfate ions. Sulfate ions normally are not required to be removed from drinking water, but are typically sorbed by the available ion exchange resins and result in inefficient use of the ion exchange capacity. The disclosed process and apparatus use an ion selective membrane to first remove the sulfate ions from the stream and then remove the nitrate ions by ion exchange.

Abstract: The invention is related to a tank for liquefied gas composed by a triple wall limiting three successive spaces from which two are insulation spaces.The external insulation space contains a substance able to sublime and condense from gaseous state to solid state when cooled by a flow of liquefied gas caused by accidental failure into space.An application is the construction of the tanks of methane carrier.