Evolutionary-ecological analysis of trends in phenogenetic variation of homologous morphological structures: From populations to ecological series of species

An evolutionary-ecological analysis of homologous variations in cranial morphological structures (phenes) has been performed at the level of populations and subspecies exposed to technogenic, climatic, and landscape-geographic changes in the environment, as well as with ecological series of 46 species and infraspecific forms differing in ecological specialization within the family Cricetidae. On this basis, consistent manifestations of phenogenetic variation have been revealed. Species with the same ecological specialization show parallel directional changes in the frequencies of homologous phenes and their individual combinations. These changes apparently have adaptive significance and result from rearrangements in the ancestral epigenetic system. It is shown that similar ecological requirements imposed by the environment historically lead to unidirectional transformations of homologous morphological structures in different species, which may account for high incidence of homoplasy as well as for the parallel and, in part, directional evolution of closely related taxa with similar ecological specialization.     

Comparison of the performance of different methods to stabilize mercury-containing waste

Journal of Material Cycles and Waste Management - The work is devoted to the study of a possible technology for the immobilization of mercury in waste, based on the principles of converting mercury...     

Catalytic oxidation of TNT by activated carbon

Activated carbon can remove 2,4,6-trinitrotoluene (TNT) and 1,3,5-trinitrobenzene (TNB) from aqueous solution and promote oxidation of TNT. After equilibrating a 0.35 mM TNT solution with activated carbon (0.2-1% w/v), HPLC and GC/MS analysis confirmed the presence of 2,4,6-trinitrobenzaldehyde (TNBAld) and 2,4,6-trinitrobenzene (TNB), and provided strong evidence supporting 2,4,6-trinitrobenzyl alcohol (TNBAlc) as an intermediate of TNT oxidation. After 6 d, TNT and its oxidation products were strongly bound to the activated carbon, while TNB was extractable with acetonitrile. Observations indicate that activated carbon catalyzes TNT oxidation to TNBAlc, which is readily oxidized to TNBAld and TNB in the absence of activated carbon under dark conditions. While adsorbed TNB was extractable with acetonitrile, activated carbon promoted rapid TNT oxidation and formation of unextractable residues. Strong binding is attributed to catalyzed oxidation of the TNT methyl group, probably through a free radical mechanism, and subsequent chemisorption of oligomers and polymerized products that are not desorbed from micropores. Our observations indicate TNT oxidation and bound residue formation after sorption by activated carbon increases the effectiveness of activated carbon to decontaminate water.     

Dynamics of PCB removal and detoxification in historically contaminated soils amended with activated carbon

Activated carbon (AC) can help overcome toxicity of pollutants to microbes and facilitate soil bioremediation. We used this approach to treat a Histosol and an Alluvial soil historically contaminated with PCB (4190 and 1585 mg kg⁻¹, respectively; primarily tri-, tetra- and pentachlorinated congeners). Results confirmed PCB persistence; reductions in PCB extractable from control and AC-amended soils were mostly due to a decrease in tri- and to some extent tetrachlorinated congeners as well as formation of a bound fraction. Mechanisms of PCB binding by soil and AC were different. In addition to microbial degradation of less chlorinated congeners, we postulate AC catalyzed dechlorination of higher chlorinated congeners. A large decrease in bioavailable PCB in AC-amended soils was demonstrated by greater clover germination and biomass. Phytotoxicity was low in treated soils but remained high in untreated soils for the duration of a 39-month experiment. These observations indicate the utility of AC for remediation of soils historically contaminated with PCB.     

Express-phytotest for choosing conditions and following process of soil remediation

Environmental Geochemistry and Health - Phyto- and bioremediation are perspective methods for soil recultivation. In spite of resistance of plant-hyperaccumulators and degrading microorganisms to...