A new, simple, sensitive and selective method for the simultaneous determination of trace iron and aluminum by catalytic spectrophotometry was presented, based on the catalytic effects of iron and aluminum on the discoloring reaction of xylene cyanol FF proceeded by hydrogen peroxide and potassium periodate in weak nitric acid medium. No catalytic effect was obtained in the presence of hydrogen...

The removal of xylene vapors was studied in a biofilter packed with a new hybrid (scoria/compost) packing material at various inlet loads (IL) and empty bed residence times (EBRT) of 90, 60, and 40s. The best performance was observed for EBRT of 90s, where a removal efficiency of 98% was obtained under steady state condition for inlet xylene concentration of 1.34 g m(-3), while a maximum elimin...

Alkylbenzenes, such as toluene and m-xylene, are an important class of contaminant hydrocarbons that are widespread and tend to accumulate in subsurface anoxic environments. The peripheral pathway for the anaerobic oxidation of toluene in bacteria consists of an initial activation catalyzed by a benzylsuccinate synthase (encoded by bss genes), and a subsequent modified β-oxidation of benzylsucc...

Molecular sieving MFI-type zeolite membranes were prepared by a secondary growth method without using an organic template. Silicalite membranes with intercrystalline pores minimized or eliminated were obtained by this synthesis method which avoids the template removal step. The silicalite membrane exhibits molecular sieving characteristics with pervaporation separation factor for p-xylene to o-...

Four pure cultures of denitrifying bacteria, which had previously been isolated on defined alkylbenzenes, were capable of anaerobic growth with crude oil as the only source of organic substrates. Chemical analyses after growth revealed that the known growth substrates toluene, ethylbenzene, and m-xylene were selectively consumed from the oil. o-Xylene and p-xylene, which as pure compounds did n...

A physiological pharmacokinetic model of the transfer of organic solvents in the human body was developed. The model was comprised of seven compartments, i.e., lungs, vessel-rich tissues, vessel-poor tissues, muscles, fat tissues, gastrointestinal tissues, and liver, each being connected to the others by blood fiow. The transfer of organic solvents was expressed by simultaneous differential equ...

Toluene and o-xylene were completely mineralized to stoichiometric amounts of carbon dioxide, methane, and biomass by aquifer-derived microorganisms under strictly anaerobic conditions. The source of the inoculum was creosote-contaminated sediment from Pensacola, Fla. The adaptation periods before the onset of degradation were long (100 to 120 days for toluene degradation and 200 to 255 days fo...