Slow-releasing permanganate ions from permanganate core-manganese oxide shell particles for the oxidative degradation of an algae odorant in water.

In this work, potassium permanganate particles (KMnO) were modified with a manganese oxide (MnOx) shell comprising passages for the slow release of permanganate ions (MnO) in aquatic systems. The bare particle (KMnO) and KMnO core-MnOx shell particles (CP-60) were characterized by attenuated total reflectance (ATR)-Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), thermogravimetric analysis (TGA), and X-ray photoelectron spectroscopy (XPS). The CP-60 were evaluated as a slow source of MnO for the oxidative treatment of pure and lake water containing dimethyl trisulfide (DMTS), a water odorant produced by cyanobacteria in many eutrophic waters.

Interaction between bisphenol A and tannic acid: spectroscopic titration approach.

The interaction between tannic acid (TA) and bisphenol A (BPA), an endocrine disruptor, was studied by absorption and fluorescence titration techniques. The binding constants and corresponding thermodynamic parameters at different temperatures (294, 296, 298, 300 and 303 K) were determined. The intrinsic fluorescence of BPA was strongly quenched by TA and the quenching mechanism is attributed to static quenching.

Adhesion of bacterial exopolymers to alpha-FeOOH: inner-sphere complexation of phosphodiester groups.

Extracellular polymeric substances (EPS) constitute a heterogeneous mixture of polyelectrolytes that mediate biomineralization and bacterial adhesion and stabilize biofilm matrixes in natural and artificial environments. Although nucleic acids are exuded extracellularly and are purported to be required for biofilm formation, direct evidence of the active mechanism is lacking. EPS were extracted from both Bacillus subtilis (a gram-positive bacterium) and Pseudomonas aeruginosa (a gram-negative bacterium) and their interaction with the goethite (alpha-FeOOH) surface was studied using attenuated total internal reflection infrared spectroscopy.

Spectroscopic study of extracellular polymeric substances from Bacillus subtilis: aqueous chemistry and adsorption effects.

Reactions at ionizable functional groups in extracellular polymeric substances (EPS) from Bacillus subtilis are found to affect aqueous phase conformation and adsorption to mineral surfaces. Characterization by HPSEC, XPS, and FTIR indicates a wide range in apparent molecular mass (0.57-128 kDa), with functional group composition depending on cell growth phase (exponential vs stationary) and location in suspension (free vs cell-bound).