Acute and sub-lethal toxicity of landfill leachate towards two aquatic macro-invertebrates: demonstrating the remediation potential of air stripping.
A specific leachate that contained 1.036 mg l(-1) of 2-chlorobiphenyl was used in the study (255 mg l(-1) COD and 133 mg l(-1) BOD5). Bench scale (20 l) air stripping trials were used to simulate on a small-scale the treatment potential of this method. Air stripping effectively reduced the leachates COD concentration. Regardless of the volume of air supplied (1-5 l of air per minute) the leachates COD reached a <50 mg l(-1) equilibrium after 96-h exposure, however, increasing the volume of air accelerated the process. In untreated leachate, the LC50 for Asellus aquaticus was 57% v/v leachate in deionised water and 5% for Gammarus pulex (96-h, static LC50 tests without nutrition and oxygen depleting conditions). After being exposed to air stripping, these values rose from 90% to below the LC50 threshold for Asellus when 1-5 l of air per minute were applied and 30-90% for Gammarus. Furthermore, in sub-lethal concentrations of air stripped leachate (leachate that had been exposed to 5-l of air per minute for 96-h) the population dynamics of both test species remained unaltered.
Bloor
M C
MC
School of Civil Engineering and the Environment, University of Southampton, Highfield, Southampton SO17 1BJ, UK. M.C.Bloor@soton.ac.uk
Banks
C J
CJ
D000388:Air; D033304:Amphipoda; D000818:Animals; D001713:Biphenyl Compounds / Q000302:isolation & purification / Q000633:toxicity*; D033321:Isopoda; D007928:Lethal Dose 50; D011157:Population Dynamics; D014865:Waste Disposal, Fluid; D014873:Water Pollutants / Q000302:isolation & purification / Q000633:toxicity*; D018508:Water Purification
D001713:Biphenyl Compounds; D014873:Water Pollutants; C055142:2-chlorobiphenyl