Due to the lower energy consumption and waste production compared to traditional methods, the environmental bioremediation methods based on natural processes have been gradually becoming more prevalent in environmental engineering. Biological methods are used in waste management, wastewater treatment, gas treatment or soil remediation. For the low solubility of some pollutants and lower bioavailability, the use of biological methods may be hampered. This problem might be mitigated with the use of surfactants. This paper presents the results of studies regarding the eff ect of dosing a selected surfactant from the Tween group (Tween 20) on the efficiency of toluene elimination from the air by biofi ltration. The obtained maximum biofi ltration rate was 21.2 g/m3/h and 19.8 g/m3/h for the control bed and for the bed to which the Tween 20 solution was dosed, respectively. The eff ect of Tween was neutral (the effectiveness of toluene removal was insignificantly comparable to the effectiveness of the control series), it did not affect the effectiveness or limited the development of the biofilter microflora.

The removal of benzene (B) and toluene (T) from aqueous solution by multi walled, single walled, and hybrid carbon nanotubes (MWCNTs, SWCNTs, and HCNTs) was evaluated for a nanomaterial dose of 1 g/l, concentration of 10-100 mg/l, and pH 7. The equilibrium amount removed by SWCNTs (B: 9.98 mg/g and T: 9.96 mg/g) was higher than for MWCNTs and HCNTs. Toluene has a higher adsorption tendency on CNTs than benzene, which is related to the increasing water solubility and the decreasing molecular weight of the compounds. The SWCNTs performed better for B and T sorption than the MWCNTs and HCNTs. Isotherms study based on isofit program indicate that the Generalized Langmuir-Freundlich (GLF) isotherm expression provides the best fit for benzene sorption, and that Brunauer-Emmett-Teller (BET) isotherm is the best fit for toluene adsorption by SWCNT. SWCNTs are efficient B and T adsorbents and possess good potential applications to water and wastewater treatment and maintain water of high quality that could be used for cleaning up environmental pollution.

Results of toluene and p-xylene containing model gases biofiltration are presented. Process was carried out on columns packed with two kinds of non-modified composts. Velocity and efficiency of biofiltration was determined and plotted vs. impurities concentration and linear gas velocity. Highest, average for the top section of the column, values of the decomposition velocity were found to be ca. 80 g/m3 /h, and average for the whole column ca. 40 g/m3/h respectively. Fluctuations of these values at similar, well controlled, measurement parameters were however encounter, most probable due to varying hardly adjustable humidity of the column bed.