An object of the invention is to provide a heat-resistant hexavalent chromium removal agent, which is capable of remaining in a leather or leather article for a long period of time and stably detoxifying hexavalent chromium over the long term even when a leather or leather article contains hexavalent chromium, and a leather or leather article, in which the hexavalent chromium content is less than 3 ppm. The leather or leather article of the present invention contains at least: an organic compound (A) having a structure shown in chemical formula (1) and hydroxyphenyl but not aldehyde and carboxyl, which organic compound has a property to reduce hexavalent chromium to trivalent chromium; and trivalent chromium, and the hexavalent chromium content determined in accordance with ISO 17075: 2008-02 is less than 3 ppm.

A method for precipitating metal waste is characterized in that the waste which contains one or more dissolved metal salts, is mixed with a boron compound, and the pH is adjusted to a value at which precipitation takes place in the presence of precipitation nuclei necessary for the formation of metal borates.

Provided are astexin-1, astexin-2 and astexin-3 lasso peptides, which are based on sequences identified in Asticcacaulis excentricus, and methods of making and using same.

Astexin-1 is highly polar, in contrast to many lasso peptides that are primarily hydrophobic, and has modest antimicrobial activity against Caulobacter crescentus, a bacterium related to Asticcacaulis excentricus. The solution structure of astexin-1 was determined, revealing a unique topology that is stabilized by hydrogen bonding between segments of the peptide. Astexins-2 and -3 are intracellular lasso peptides.

Provided is a hexavalent chromium treatment agent capable of penetrating inside of a leather and capable of reducing not only hexavalent chromium present in the vicinity of the surface of the leather but also hexavalent chromium present inside the leather into trivalent chromium. The hexavalent chromium treatment agent of the present invention comprises a hexavalent chromium-reducing compound capable of reducing hexavalent chromium into trivalent chromium, a nonionic surfactant, and an aqueous solvent. The hexavalent chromium-reducing compound preferably comprises an organic compound (A) that has a specific structure capable of acting to reduce hexavalent chromium into trivalent chromium, that has a hydroxyphenyl group, and that has no aldehyde groups and no carboxyl groups.

Provided is a practically valuable and economically excellent insolubilizing material for a specific toxic substance: that is useful for insolubilizing treatment for a heavy metal or the like conducted by applying the insolubilizing material for a specific toxic substance to soil or on the surface of the soil; that is capable of effectively insolubilizing and immobilizing the heavy metal or the like; that is capable of making treated matter neutral so as to be reusable and environment-friendly; and moreover that is capable of imparting strength to the treated matter as necessary; and with which the heavy metal or the like is not re-eluted even when the treated matter is exposed to an environment under a neutral condition or an acidic condition. An insolubilizing material for a specific toxic substance to be used so that soil does not reach a strongly alkaline region of a pH of 11 or more, wherein the insolubilizing material for a specific toxic substance comprises an amorphous aluminum compound or a derivative thereof as a main component, or an insolubilizing material for a specific toxic substance to be used so that soil containing a heavy metal or the like does not reach a strongly alkaline region of a pH of 11 or more, the insolubilizing material for a specific toxic substance functioning also as a solidifying material, wherein the insolubilizing material for a specific toxic substance comprises gypsum obtained by adding and mixing, to the gypsum, the amorphous aluminum compound and the derivative thereof in a range of 0.5 to 60 mass parts relative to 100 mass parts of the gypsum, and a method for improving soil using the insolubilizing material for a specific toxic substance.

Provided are: a novel heavy metal treatment agent having improved performance for treating elements of groups 6-16 of the periodic table or compounds thereof, including treatment of incinerated ash and wastewater, etc.; and a method for treating incinerated ash and wastewater using the heavy metal treatment agent. This heavy metal treatment agent includes at least one dithiocarbamate of one or more amine compounds represented by any of formulae (I) to (III):

##STR00001## wherein m represents an integer of 3 to 6;

##STR00002## wherein each of the n Xs independently represents a hydrogen atom or a 2-aminoethyl group, at least one X is a 2-aminoethyl group, n is an integer of 1 to 3 and the total number of nitrogen atoms is 4 to 8; and

##STR00003## wherein o is an integer of 0 to 2, p is 0 or 1, q is 0 or 1, r is an integer of 0 to 3, the sum of o, p and r is greater than or equal to 1, and the total number of nitrogen atoms is 3 to 7.

Provided are astexin-1, astexin-2 and astexin-3 lasso peptides, which are based on sequences identified in Asticaccaulis excentricus, and methods of making and using same. Astexin-1 is highly polar, in contrast to many lasso peptides that are primarily hydrophobic, and has modest antimicrobial activity against Caulobacter crescentus, a bacterium related to Asticaccaulis excentricus. The solution structure of astexin-1 was determined, revealing a unique topology that is stabilized by hydrogen bonding between segments of the peptide. Astexins-2 and -3 are intracellular lasso peptides.

Disclosed is a method for stabilizing metallic mercury in the form of mercury sulfide. The method includes the following steps: a) dispersing metallic mercury in a polysulfide aqueous solution so as to convert the metallic mercury into mercury sulfide; and b) separating the mercury sulfide.

Disclosed herein is a method of remediating chromated copper arsenate (CCA) treated timber. Particularly, the method comprises contacting the CCA timber with an oxidative solvent and an acidic solvent which provides remediated timber and a variety of extracts containing amongst other things the metals of concern. One or more of the steps is conducted using continuous counter current extraction (CCE).

A method of treating, stabilizing, precipitating, or otherwise removing heavy metal ions contained in a contaminated media, which method includes: providing a sodium-iron-sulfide mineral or crystalline phase, either alone or in combination with a pH adjusting substance; contacting said contaminated media containing heavy metal ions with the sodium-iron-sulfide mineral or crystalline phase, either alone or in combination with a pH adjusting substance; and allowing the contaminated media containing the heavy metal ions to react with said sodium-iron-sulfide mineral or crystalline phase, either alone or in combination with a pH adjusting substance, such that the contaminated media containing heavy metal ions form single or mixed metal-sulfide precipitates or co-precipitates.