Development of the basics of complex technology for capturing and disposing of heavy metals from surface drains of cities.

For the first time, the basics of waste-free technology for capturing heavy metal ions from urban surface runoff from residential areas of the city with the final utilization of the regenerate were developed. The technology eliminates the subsequent contamination of the lithosphere and atmosphere by regeneration products. The expediency of using fibrous chemosorbents (cationic and polyampholyte) for capturing heavy metal ions from urban surface runoff of residential areas of megalopolises has been justified because of possibility of recycling heavy metal ions and regenerating the sorbent.

Symmetric C-C stretching mode splitting versus CH2-chain conformation order in sodium montmorillonite modified by cetyltrimethylammonium bromide.

Exploiting Raman spectroscopy and computational modeling, for the first time, we report and explain an interesting phenomenon in clay modified by cetyltrimethylammonium bromide. A splitting of the CH(2)-chain's symmetric C-C stretching Raman mode found at ~1128 cm(-1) in cetyltrimethylammonium bromide into two bands at 1128 and 1139 cm(-1) in clay modified by cetyltrimethylammonium bromide is observed. We demonstrate that this splitting appears if two types of trans-segments with nonequivalent lengths and terminal groups coexist in the CH(2)-chain of the alkylammonium ion embedded into the clay interlayer space.

Raman spectroscopic characterization of the interlayer structure of Na+-montmorillonite clay modified by ditetradecyl dimethyl ammonium bromide.

Raman spectroscopy has been applied for the rapid and nondestructive monitoring of the interlayer structure of sodium montmorillonite (MMT) clay modified by ditetradecyl dimethyl ammonium (DDA+) bromide. This work demonstrates that a detailed analysis of Raman spectra in the fingerprint region (600-1600 cm(-1)), in combination with model simulation, allows one to distinguish different conformational states of DDA+ in the interlayer space of the modified clay, namely, a liquidlike state but rich in trans conformers, disordered conformational states, and a crystallike conformation appearing at increasing modifier content. These conformations differ in the angle between their alkyl chains, the relative content of trans and gauche conformers and the relative length of trans segments.