The topsoils of the Mashavera valley in SE Georgia are highly contaminated with Cu, Zn and Cd from mining activities in the upper reaches of the Mashavera River. Previous laboratory experiments have shown that an in situ immobilization of these metals (M) by Fe-oxides would be an adequate remediation technique for the study area. A field experiment was thus initiated in 2008 in order to assess such a treatment under natural conditions. To verify the results a pot experiment was conducted in a growth chamber. Two experimental fields with differing degrees of M contamination were chosen close to the town of Bolnisi, Georgia, and divided into 8 (Field I, weakly contaminated) and 16 (Field II, heavily contaminated) plots. Half of the plots at each field were chosen for remediation. A 1% (w/w) zerovalent iron grit was applied homogeneously and mixed in the topsoils (to a depth of 0-20 cm) of the treatment plots. Composite samples of all plots were taken directly after remediation

Agriculturally used soils (Kastanozems) of experimental fields in the Mashavera Valley in southeast Georgia show various degrees of trace metal contamination (Cd, Cu, and Zn). Therefore, one part of the soils was remediated with iron grit. The effects of the remediation in comparison to nonremediated soils on microbial diversity and activity were analyzed with the single-strand conformation polymorphism (SSCP) and microbial respiratory activity. All topsoils were characterized by neutral to weakly alkaline pH values, high contents of Corg, and clay. The total contents ranged between 0.46 and 5.89 mg kg−1 for Cd, between 1.19 and 81.4 mg kg−1 for Cu, and between 210 and 976 mg kg−1 for Zn. Basal respiration was significantly (p ≤ 0.05) lower in the heavily contaminated soils as compared to the weakly contaminated and control soils. Phylogenetic analyses of the DNA bands found 40 operational taxonomic units with ≥98 % sequence identity. The phylum Acidobacteria dominated with 57.7 %. Other groups detected were Proteobacteria (α (2.8 %), β (8.5 %), γ (14.1 %), δ (4.2 %)), Bacteroidetes (5.6 %), Firmicutes (4.2 %), Actinobacteria (1.4 %), and Nitrospira (1.4 %). Furthermore, the results of the SSCP analysis and the Shannon–Weaver indices suggested that microbial diversity was lower in the heavily contaminated soils, but DNA band profiles of the remediated soils were in higher number than in the untreated soils. Due to the remediation, a recovery of the microbial diversity seems attainable

The aim was to find an adequate, cost-efficient in situ remediation technique for the Mashavera valley, a mining area in SE Georgia heavily contaminated with Cd, Cu, and Zn. A 12-month experiment was conducted to test: iron grit, natural zeolite, biochar, and Divergan ® (a scavenger) for soil melioration. The amendments were added in different concentrations to the topsoil of a Kastanozem. Mobile metal concentrations decreased with increasing concentrations of amendments in the sequence Divergan ® >> iron grit ≈ natural zeolite > biochar. In the same order amendments enhanced activities of soil microbial respiration, alkaline phosphatase, and dehydrogenase; microbial C also followed this trend. A sequential extraction confirmed a shift from easily mobilized to heavily bound fractions. The addition of 2% (w/w) of Divergan ® was sufficient to lower mobile trace metal concentrations below German thresholds by chemisorption, and soil microbial activity was significantly increased. The effects of all other treatments were at a much lower level and not found suitable due to needed application rates.

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Chemical tools that recognise post-translational modifications have promising applications in biochemistry and in therapy. We report a simple carboxycalixarene that selectively binds molecules containing di/trimethylammonium moieties in isolation, in cell lysates and when incorporated in histone peptides. Our findings reveal the potential of using carboxycalixarene-based receptors to study epigenetic regulation.