New Technologies for Anaerobic Wastewater Treatment

Presently anaerobic wastewater treatment is becoming an accepted simple technology for the treatment of a variety of wastewaters. Of the different treatment systems that have been developed the UASB process (Upflow Anaerobic Sludge Blanket) has found the widest application. Almost all of the more than 60 full scale UASB reactors in operation now, are running satisfactorily. The excellent sludge retention generally found in UASB-reactors is obtained by sludge granulation, which can be seen as a sludge immobilization process. The presently available insight into the sludge granulation process is briefly presented, together with the strategy to be applied for performing a proper first start-up and secondary start-up of UASB reactors, viz. using granular seed sludge. The effect of the presence of SS with regard to the loading potentials of anaerobic treatment systems will be discussed. The experiences obtained with some full scale applications of the UASB-process are presented.