The pig raising industry in Vietnam currently tends to shift from a small scale to a concentrated raising with different farm-scales. Along with that trend, the problem of environmental pollution from livestock production in rural areas is becoming more and more serious due to the high density of livestock in one location while waste treatment methods are still simple (mainly biogas) and can not fully treat the pollution problem. Currently, there are many technologies applicable for waste and wastewater treatment in pig-rising sector, including: (i) natural treatment solution which is cheap but requires a lot of space (ponds, lakes, wetland, etc.)
(ii) high treatment efficiency (Aerotank, MBR, JOHKASOU) using less space requirement but expensive
and (iii) semi-natural treatment technologies that combines two biological treatment processes (anaerobic, aerobic) to limit the disadvantages and take advantages of the two above mentioned technologies. This paper presents the results of research on selection of a reasonable number of anaerobic treatment modules, including: Anaerobic Baffle Reactor (ABR) and Anaerobic Filter (AF) of the wastewater treatment plan in pig-farm raising sector as a basis for standardizing the technological solution of wastewater treatment for small and medium-scaled in the North Central Region in Vietnam