Comparison is made between a combined quantum mechanics/interatomic potential function approach ~QM-Pot! and its fully quantum-mechanical limit, ab initio calculation applying periodic boundary conditions. The Hartree–Fock ~HF! method is combined with ab initio-parametrized ion pair shell model potential functions. The CRYSTAL code is employed for the periodic Hartree–Fock calculations. The sam...

The removal efficiency of sediment phosphorus (P) in all fractions with in-situ adsorption-biological combined technology was studied in West Lake, Hangzhou, China. The removal amounts of sediment Ca-P, Fe/Al-P, IP, OP and TP by the combined effect of PCFM (Porous ceramic filter media) and V. spiralis was 61 mg/kg, 249 mg/kg, 318 mg/kg, 85 mg/kg and 416 mg/kg, respectively, and the correspondin...

The mobility of phenanthrene (PHE) in soils depends on its sorption and is influenced by either the existing soil humus or exogenous humic substances. Exogenous humic acids (HAs) were added to soil to enhance the amount of soil organic carbon (SOC) by 2.5, 5.0, and 10.0 g kg(-1). PHE desorption of the treated soils was determined at two pH levels (3.0 and 6.0) and temperatures (15 and 25 degree...

The adsorption of selenite on goethite (a-FeOOH) has been analyzed with the charge distribution (CD) and the multi-site surface complexation (MUSIC) model being combined with an extended Stern (ES) layer model option. The geometry of a set of different types of hydrated iron-selenite complexes has been calculated using Molecular Orbital / Density Functional Theory (MO/DFT). The optimized geomet...

A series of styrene/butadiene polymers were combined with up to 90 wt% UiO-66 to form mixed-matrix membranes with varying physical properties. Notably, polystyrene-block-polybutadiene (SBS) membranes retained much of the processability and flexibility of the native polymer component and the porosity, chemical tunability, and adsorption of the native MOF.

Based on single molecule manipulation experiments in a combined scanning tunneling microscope/frequency modulated atomic force microscope, we quantify the individual binding energy contributions to an organic-metal bond experimentally. The method allows the determination of contributions from, e.g., local chemical bonds, metal-molecule hybridization, and van der Waals interactions, as well as t...

Remediation of Cr(VI)-contaminated soil usually includes reducing Cr(VI) to Cr(III) with sub-sequent solidification. In this paper, a treatment technique that combines reduction, adsorption, and solidification was proposed. By introducing an adsorbent into the reduction process, remediation effectiveness improved amount solidified agent decreased. Synthetic precipitation leaching procedure (SPL...

Organic matter (OM)-mineral complexation plays a critical role in soil carbon (C) stabilization. However, direct investigations of organo-mineral associations have been hampered by a lack of methods that can simultaneously characterize soil organic matter and soil minerals. We have applied scanning transmission X-ray microscopy (STXM), combined with near edge X-ray absorption fine structure (NE...