Large-scale Application of Klozur® CR for the Treatment of an Aquifer Contaminated with Heavy Hydrocarbons and MTBE in Southern Italy

Klozur® CR is a combined remedy treatment technology consisting of Klozur® SP and PermeOx® Ultra. Klozur CR is a single, all-in-one formulated product that can be readily applied to either source areas or plumes with mixed petroleum and chlorinated solvents contamination. Klozur CR destroys contaminants in soil and groundwater by promoting three modes of action: Klozur activated persulfate chemical oxidation, aerobic bioremediation and anaerobic bioremediation. This technology was successfully applied to a site in southern Italy, contaminated by the storage and sale of fuels. The groundwater was contaminated by heavy chain hydrocarbons (TPH> 2500 μg / l) and MTBE (> 150 μg / l) in proximity to the reservoir park. During the site maintenance activities, the qualitative status of adjacent coastal waters was also verified, which, however, were found to be compliant. Previously the site used a pump and treat system, but it was unable to achieve remedial goals. Klozur CR was injected and within 4 months, the concentrations of the contaminants were found to have reached the remedial goals. In addition, monitoring data also confirmed enhanced ISCO conditions and enhanced aerobic bioremediation were present at the site.

Sustainable remediation of antibacterials, metals and DNA

The global antibacterial crisis requires urgent attention from environmental engineering and bioengineering. Here, unit operation efficiencies are assessed, in a novel water treatment train capable of remediating antibacterials, metals and DNA. This technological cycle relies on bioremediation, high temperature and pressure. The analyses used 14C-respirometry, spectrometry, and a set of molecular analyses. Multiresistant bacteria hold antibacterial resistance genes (ARGs); they were harnessed for bioremediation of pollutant mixtures. Treatment efficiencies were 25-71% for 8-days aerobic metal reduction and removal (CrVI: 255, Cd: 0.65, and Pb: 0.65 mg L-1 initial concentrations); 34.8% erythromycin (ERY) 20-days biodegradation (from 750 mg L-1). The anaerobic digestion (AD) bioremediated mixed antibacterials (65-73% in 60 days from initial 100 mg L-1). However, high concentrations of mixed antibacterials (SMX+ERY) induced stronger inhibition of enzymatic activity, higher sensitivity of bacteria and acetoclastic methanogens, and higher diversity of ARGs. ARGs justified complete DNA degradation (60°C at 5.8 kPa for 10 min). The suggested coupling sequence of operations was metal then antibacterial aerobic bioremediation (as pre-treatments to anaerobic digestion), anaerobic bioremediation (also yielding biomethane as heat source), recirculation of ARGs in situ, and thermal-barometric DNA degradation.