As described by Cruz et al. (2013), this project was carried out in
an area reserved for research efforts at the School of Civil
Engineering, Architecture and Urbanism of UNICAMP, in Brazil.
The untreated wastewater was collected from the university
campus wastewater network, which had part of its outflow routed
to four anaerobic
filters. The reactors were made of stainless steel,
had a cylindrical shape and total volume of 500 L (Fig. 1). The
filters
were 1.68 m long, with a diameter of 0.76 m. A bamboo grid was
used to separate the coconut shells from the conical bottom, and
also served the purpose of improving wastewater distribution.