Compact small-scale waste water treatment plant for country districts is flexible at high and low volume rates and requires less energy

摘要

A biological waste water treatment plant for use in country districts has a conventional three-chamber (17) assembly operated by a control unit, with pumps and ventilators. The overall size of the assembly is determined primarily by the size of the biological stage (2). The assembly especially has chambers which are discrete and whose walls are not penetrated by slits, slots or pipes. The component parts of the assembly are a primary sludge and balancing tank (1), a biological treatment tank (2) and an excess sludge holder (3). In addition to the water inlet and outlet, the assembly consists only of pumps (7, 11, 12), float-switches (4, 5, 6) and ventilation distributor (9). The size of the biological treatment tank (2) is chosen to stabilize the sludge at 0.05 g COD (5/g dry matter and a sludge life of 20 d. Control of the process and assembly is by means of a programmable logic control module which calculates actions using information based on volume flow and installation depth. The container may be made from any suitable material.