Diethyldithiocarbamate (DDTC) has been employed in the sulfide ore flotation process, due to its excellent collection performance. Herein, we investigated the interfacial adsorption behavior of DDTC on four mineral phases of high-sulfur residue — sulfur, pyrite, sphalerite and lead sulfate. The adsorption behavior — adsorption structure and energy and electron localization function cross section — of DDTC and H2O were explored using density function theory calculation. The result was helpful to construct a co-adsorption model of DDTC and H2O, which was validated by the pure minerals flotation operation and the characterization of fourier transform infrared spectra. The co-adsorption model indicated that the DDTC adsorption on the sulfur, sphalerite and lead sulfate was weak with physical bonding, while its adsorption on the pyrite was strong with chemical bonding. Practical bench-scale operation of high-sulfur residue flotation was performed, whose result was different from that obtained from the pure mineral flotation. To explain the difference, our developed model predictions and the mineral fugacity pattern analysis on the high-sulfur residue flotation were synergistically used. Overall, this work first proposed the co-adsorption model of DDTC and H2O and provided important insights into the interfacial adsorption in the high-sulfur residue flotation.

Ureaplasma species (Ureaplasma spp.) are commonly found as commensals in the human urogenital tracts , but their overgrowth can lead to infection in the urogenital tract and at distal sites. Treatment of Ureaplasma spp. infections is difficult. The lack of a cell wall confers resistance to all β-lactam and glycopeptide antibiotics whereas the lack of de novo synthesis of folic acid makes them resistant to sulfonamides and diaminopyrimidines. Thus, there is a need to search for new drugs effective against these bacteria. In the presented studies, the effect of N,N-diethyldithiocarbamate (DDC) at a concentration of 2 µg/ml, 20 µg/ml and 200 µg/ml on the growth and survival of Ureaplasma urealyticum and Ureaplasma parvum was tested. Our results indicated that all DDC concentrations used showed both bacteriostatic and bactericidal activity against both tested strains In brief, for the first time we showed the bacteriostatic and bactericidal activity of DDC against Ureplasma urealyticum and Ureaplasma parvum. Based on literature data, we conclude that this DDC activity is related to the inhibition of urease activity, which is an indispensable enzyme for these bacteria. Further research is needed and the results obtained in the present study should be verified in in vivo models of infection.