A common,\nyet tricky problem in pure water systems is the accumulation of biofouling on\nosmosis membranes, which is usually combated with chemical biocides. NWTR was\nthe first in the world to develop a better solution: an intermediate step with\na biological active carbon filter. <\/p>\n\n\n\n
This filter\nhas a large surface area for bacteria to attach to. After a start-up period of\na few months, this filter will be full of bacteria. Adding oxygen optimises the\nconditions for bacterial growth, to the point that they will use up all the\nnutrients present in the water. Now the water has been depleted of all\nnutrients, bacteria will no longer be able to grow, thus preventing the\naccumulation of biofouling in the rest of the process. The filters are rinsed\nperiodically to remove any excess bacteria, which are then returned to the\nWWTP. In order to optimise the process, the system consists of a series of two\nfilters.<\/p>\n\n\n\n