Overview of on‐farm bioremediation systems to reduce the occurrence of point source contamination

Abstract

Contamination of ground and surface water puts pressure on the use of pesticides. Pesticide contamination of water can often be linked to point sources rather than to diffuse sources. Examples of such point sources are areas on farms where pesticides are handled and filled into sprayers, and where sprayers are cleaned. To reduce contamination from these point sources, different kinds of bioremediation system are being researched in various member states of the EU. Bioremediation is the use of living organisms, primarily microorganisms, to degrade the environmental contaminants into less toxic forms. The systems available for biocleaning of pesticides vary according to their shape and design. Up till now, three systems have been extensively described and reported: the biobed, the Phytobac and the biofilter. Most of these constructions are excavations or different sizes of container filled with biological material. Typical overall clean-up efficiency exceeds 95%, realising even more than 99% in many cases. This paper provides an overview of the state of the art of these bioremediation systems and discusses their construction, efficiency and drawbacks.

Robust Linuron Degradation in On-Farm Biopurification Systems Exposed to Sequential Environmental Changes

“…In case effects occur, the restoration of the selective conditions seems to rapidly result into the reestablishment of the pesticide-degrading capacity. Those data are in support of the use of BPS for the treatment of pesticidecontaminated wastewater at farm yards (6).…”

“…The treatment of pesticide-contaminated wastewater in onfarm biopurification systems (BPS) is a low-cost and effortless solution for farmers to minimize the direct losses of pesticides to surface water (6). On-farm BPS operate as biofilters in which the pesticides are removed from the wastewater by biodegradation and sorption processes occurring in the biofilter matrix.…”

“…On-farm BPS operate as biofilters in which the pesticides are removed from the wastewater by biodegradation and sorption processes occurring in the biofilter matrix. The matrix in a BPS, designated a biomix, is composed of a mixture of soil, peat, and straw or other organic waste materials (6,9). The addition of pesticide-primed soil to BPS has been proposed as an alternative for bioaugmentation with axenic cultures of specialized pesticide-degrading bacteria to accelerate pesticide degradation and avoid the production of toxic metabolites (7,18).…”

“…Such changes might induce stresses for specific pesticide-degrading populations in the BPS, resulting in changes in their population sizes and disturbance of BPS degradation performance (6). However, it is unknown how pesticide-degrading populations present in a BPS respond to periods of less favorable conditions, especially when they are sequentially imposed.…”

Planktonic versus Biofilm Catabolic Communities: Importance of the Biofilm for Species Selection and Pesticide Degradation

“…The influence of the biofilm architecture on the pesticide degradation characteristics also suggests that for bioaugmentation of on-farm bioremediation systems such as biofilters, phytobacs, or biobeds, the use of biofilm catabolic communities might be a proficient alternative to using planktonic freely suspended cultures (11). On-farm bioremediation systems are mostly based on sorption and the formation of more mobile intermediates (such as 3-chloroaniline) should be avoided since this could lead to a faster breakthrough of the filter system.…”