The most common systems are the UASB, Anaerobic Filter, and the Contact Process. The anaerobic process is more sensitive to potential toxicants than aerobic systems. Industrial sewage treatment is widespread in Europe, with Germany and The Netherlands as the leading countries. Also many reactors are constructed in developing countries. Mostly these reactors are of western design, but increasingly also local companies become active on the market.
Anaerobic treatment has to be combined with a proper post-treatment.
Recommendations Most big industries can invest in a high-tech western technology, that needs little extra support. There is however a strong need for the support of smaller industries. Usually these industries have little money to invest and to control the system. This indicates that there is a strong need for simple to construct and simple to operate systems for this sector. Reactors need to be constructed from construction materials that will not be attacked by corrosion.