The invention relates to a plant (1) for acidification of animal manure (5). The plant (1) comprises a process tank (2) provided with a mixing unit (3) for mixing an acidification agent (4) with a quantity of animal manure (5) in said process tank (2), and wherein said process tank (2) is furthermore provided with supply means (6) for supply of the acidification agent (4) to the animal manure (5) in the process tank (2). Moreover, the plant (1) comprises conveying means (7) for conveying a quantity of animal manure (5) from a livestock stable (8) to the process tank (2), and return means (9) for returning at least a portion of the acidified animal manure (5) from the process tank (2) to a livestock stable (8). The plant (1) is characterized in that said supply means (6) are arranged at an upper part (10) of the process tank (2) so that the acidification agent (4) can be supplied to the animal manure (5) in the process tank (2) at an upper part (11) of the animal manure (5).
