Chlorobenzene removal efficiencies and removal processes in a pilot-scale constructed wetland treating contaminated groundwater

Performance evaluation of different horizontal subsurface flow wetland types by characterization of flow behavior, mass removal and depth-dependent contaminant load

“…The use of CWs has been successfully tested in pilot- (Braeckevelt et al, 2011) and field-scale (Ferro et al, 2002;Moore et al, 2002) applications, providing data on overall contaminant removal efficiency on the basis of either concentrations or loads. CW treatment efficiency primarily depends on the contact time between the contaminated water and the filter material, including biota, as longer residence times enhance contaminant turnover (Werner and Kadlec, 1996).…”

Adaptation of a Constructed Wetland to Simultaneous Treatment of Monochlorobenzene and Perchloroethene

“…Concentration removal was most efficient in 0.3 m depth, with an annual mean concentration reduction of 64% (55.3 µmol L −1 ) between the inflow and 4 m. Annual mean concentration decrease was less pronounced in 0.5 m depth, accounting for only 29% (24.9 µmol L −1 ). The decrease of MCB concentrations was slightly lower than in 2005 (before PCE addition) when annual mean concentration decrease was found to be 76% in 0.3 m and 36% in 0.5 m depth (Braeckevelt et al 2011). Presumably, this was due to the presence of PCE and its metabolites resulting in competition for electron acceptors and nutrients, and in changes in the microbial community being potentially disadvantageous for MCB oxidizers.…”

Hexachlorobenzene dechlorination in constructed wetland mesocosms

“…Moreover, Takagi et al (2009) isolated and obtained a novel aerobic pentachloronitrobenzene-degrading bacterium which enables aerobic mineralization of HCB. Furthermore, Braeckevelt et al (2007Braeckevelt et al ( , 2011 found evidence that reductive dechlorination or other anaerobic degradation pathways of CB may simultaneously occur with aerobic degradation pathways in CWs.…”