Biofilter (right picture)
The biofilter originated in Belgium. This system consists of a number of plastic containers, 1 cubic meter of size, stacked in a vertical pile and connected with plastic valves and pipes.
Each container is filled with the biomixture where the pesticides are retained and degraded. The polluted water is collected in a tank and circulated through the filters. The effluent from the filters goes through final tanks with plants where the water is evaporated by evapotranspiration.
The biofilter can consist of two to three units depending on several factors but especially on the amounts of water to be treated.
Photo: Wageningen UR-PPO
Phytobac (left picture). This is a commercial system, developed by Bayer CropScience and inspired by the Swedish concept of the biobed. It consists of a 60 cm deep basin made of watertight materials to ensure complete retention of contaminants and effluents. The substrate consists of topsoil and chopped straw. No grass layer is placed on the top, and a cover protects the bed from rainfall. The Phytobac is intended to treat all of the contaminated volumes of water coming from tank waste and spillages during mixing/ loading, rinsing, and cleaning of sprayers. It can be used alone or connected to the mixing/loading and sprayer cleaning area. In the latter case, it is connected to a buffer tank where the effluents are collected and recirculated onto the Phytobac. The water in the Phytobac is regulated by evaporation only.
Photo: Bayer CropScience
Biodep (right picture). The biodep originated in Guatemala and was developed by Agrequima. It is inspired by the Swedish biobed, but the difference is the size of the bed. It is much smaller and enough for a person standing and filling a backpack sprayer. This is a good example of a biobed adapted to smaller farms.
Photo: Agrequima, Guatemala