No abstract

No abstract

Jet-loop type reactors developed in our group have been successfully used for biological treatment of winery and olive oil wastewaters. The objective of the present work was to study the influence of the reactor hydrodynamics, causing high shear stress applied on the nozzle and its influence on the composition of the microbial population. Winery and olive oil industry effluents were treated and analysed. Microbial consortia were enriched and selected under different bio-treatment conditions of the effluents. In the case of the winery wastewaters, the isolates identified belong to the genera of Pseudomonas and Bacillus. Saccharomyces cerevisiae was also present in the consortia but no filamentous fungi were detected. In the case of the olive oil wastewaters, Bacillus megaterium 2 was the predominant microorganism. It was not detected any type of fungi.

The present work describes a coke oven soil treatability study by land-farming, conducted on-site in a field scale facility covering 100 m2. The soil contamination was mainly due to high concentrations of polynuclear aromatic hydrocarbons (PAHs) up to 1,140 mg/Kg dry weight (sigma EPA). Along the treatment process the soil was characterised at the chemical, microbiological and ecotoxicological levels. After 3 months a reduction of 63% in total PAHs concentration was observed, being detected a more pronounced reduction for PAHs with 2, 3 and 4 rings (79%). Concomitantly, a change in the composition of the microbial population was observed with a significant increase in the PAHs degrading and total heterotrophic colonies. Concerning the ecotoxicity and genotoxicity data no effect was detected in the treated soil samples eluates.

The use of two commercial microbial inocula (Bi–Chem and Biolen M112) as reference organisms for the 5‐day biochemical oxygen demand (BOD5) test was studied using both dilution and manometric methods with the standard glucose–glutamic acid solution. A comparative study was carried out performing this test for several real effluent samples with the two commercial inocula and with a treatment plant inoculum. The microbiological characterization of these inocula was performed with the API identification system (bioMérieux S.A., France). The results obtained for the BOD5 of the standard solution are within the range for activated sludge as found in the standards of the cited methods (mean values obtained were BOD5 = 199.4 mg/L O2 [variation coefficient, VC = 4.52%] and BOD5 = 176.8 mg/L O2 [VC = 4.66%] for the Bi–Chem inoculum and BOD5 = 209.8 mg/L O2 [VC = 7.35%] and BOD5 = 228.6 mg/L O2 [VC = 9.37%] for the Biolen M112 inoculum, with the dilution and manometric methods, respectively). Moreover, Pearson rank correlation analysis for the real effluent samples indicates that correlations between the BOD5 values for the two commercial inocula and for the treatment plant inoculum were highly significant to 95% confidence (r2 = 0.922 to 1.00, p < 0.05).