[Stabilization of Cd-contaminated Soil with Thiol-modified Biochar and Response of Soil Microorganisms].

To explore the stabilization effect of livestock manure biochar on Cd-contaminated soil and its impact on the soil environment, a pot experiment was conducted to investigate the stabilization efficiency of cattle manure-biochar （BC） and thiol-modified biochar （SBC） on Cd in soil and their effect on the soil properties and microbial community. The structural equation model （SEM） was used to analyze the effect pathways of BC and SBC on the soil microbial community. The results showed that BC and SBC increased soil pH, available potassium, available phosphorus, and organic matter content but decreased soil available nitrogen content compared with those in CK. The stabilization efficiency of BC for Cd in soil was 14.97%, which was much lower than that of SBC （85.71%）. Moreover, SBC increased the abundance of dominant bacterial phyla in soil, with Proteobacteria, Bacteroidota, and Cyanobacteria increasing most significantly. SBC decreased the diversity of soil microorganisms, but the decrease was insignificant （P≥0.05） compared with that in CK and BC. SEM analysis indicated that the available phosphorus, available potassium, organic matter, and soil pH were the key factors influencing Cd availability in soil, whereas organic matter and Cd availability were the key factors affecting the soil microbial community. Overall, SBC could stabilize Cd effectively and increase the abundance of dominant bacteria and has great potential in the remediation of Cd-contaminated soil.

Enrichment and immobilization of heavy metal ions from wastewater by nanocellulose/carbon dots-derived composite.

Heavy metal ions (HMIs) have been widely applied in various industries because of their excellent physicochemical properties. However, their discharging without appropriate treatment brought about serious pollution problems. So it is desirable but challenging to rapidly and completely clean up these toxic pollutants from water, especially utilizing environmentally friendly and naturally rich biomass materials. In this work, we prepared nanocellulose/carbon dots/magnesium hydroxide (CCMg) ternary composite using cotton via a simple hydrothermal method. The removal mechanism towards Cd2+ and Cu2+ was investigated using a combination of experimental techniques and density functional theory calculations. CCMg shows a good ability to remove HMIs. It is realized that the interaction between each component of CCMg and cadmium nitrate is mainly of hydrogen/dative bonds. Cadmium nitrate is preferentially enriched by the Mg(OH)2 moiety, proved by calculated thermodynamics, interfacial interactions and charges. After transformation, the cadmium carbonate precipitate is fixed on the surface by nanocellulose (NC) via chemical coupling; and of interest is that copper ion precipitates in the form of basic sulfate. Due to its high adsorption effect and simple recovery operation, CCMg is having a wide range of application prospects as a water treatment agent.

1-Benzoyl-3,6-diphenyl-1,4-dihydro-1,2,4,5-tetra-zine.

In the title compound, C(21)H(16)N(4)O, the central tetra-zine ring adopts an unsymmetrical boat conformation with the two N atoms as the bow and stern. The crystal packing is stabilized by inter-molecular N-H-O hydrogen bonds.