Abstract: A method for decomposing struvite comprises dissolving of a feed material comprising struvite in a mineral acid. Thereby a solution having an acid pH is formed. Magnesium is removed from the solution. The removing of magnesium comprises increasing a pH of the solution to a pH in the range of 4.5 to 6, precipitating magnesium compounds that do not comprise ammonium, and separating the precipitated magnesium compounds from the solution. Thereby, the solution, after the removing of magnesium, comprises an ammonium salt of the mineral acid. An arrangement for performing such a method is also disclosed. Also, a method and arrangement for recovering at least nitrogen from waste material, based on the decomposing of struvite are disclosed.

Abstract: Method for optimising the placement of at least two pieces of information in at least one display section of a display area managed by a system, wherein said system communicates with an Information Optimisation Centre through the sending and receiving of packets of instructions and/or requests, wherein said packets of instructions comprise data regarding a location of at least one piece of information and instructions regarding at least two pieces of information are sent in the same packet.