Effects of Natural Organic Matter, Anthropogenic Surfactants, and Model Quinones on the Reduction of Contaminants by Zero-Valent Iron

Electrochemical and spectroscopic characteristics of dissolved organic matter in a forest soil profile

“…Numerous studies employing excitation emission matrix (Cory and Mcknight, 2005), electron spin resonance (Scott et al, 1998), and cyclic voltammetry (Nurmi and Tratnyek, 2002) have provided multiple lines of evidence for the presence of redox active quinone moieties in DOM. In addition, it is thermodynamically favorable for most quinones to shuttle electrons from the bulk electron donors to the terminal acceptors (Tratnyek et al, 2001). The majority of present day investigators favor a humification mechanism that lignin during microbiological attack undergoes enzymatic conversion to quinones, which polymerize in the presence or absence of amino compounds to form humic-like macromolecules.…”

Modification of ultrafiltration membrane with nanoscale zerovalent iron layers for humic acid fouling reduction

“…HS are commonly existed in natural waters in the range of a few mg/L to a few hundred mg/L C (Wall and Choppin, 2003). However, the presence of HS could cause various environmental and health problems including the followings: (1) HS could cause undesirable color and taste, which are also served as food for bacterial growth in water (Bai and Zhang, 2001); (2) HS could bind with heavy metals and biocides, yielding high concentration of these substances and enhancing their transport in water (Schmitt et al, 2003); (3) HS could react with chlorine during water treatment to form disinfection by-products, such as trihalomethane (Tian et al, 2013); (4) HS have been shown to compete with low MW synthetic organic chemicals and inorganic pollutants, reducing their adsorption rates and equilibrium capacities (Tratnyek et al, 2001;Klausen et al, 2003); (5) HS could act as a major foulant causing serious microfiltration (MF)/ultrafiltration (UF) membrane fouling during filtration Zydney, 1999, 2000). As such, the removal of HS has been widely investigated to minimize their impact on environmental and human health.…”

Decolorization and Degradation of Azo Dyes by Redox Mediator System with Bacteria

“…On the other hand, the inhibitory effects are also discussed in several reports [51,52]. However, there are few literatures about the exact and well catalytic mechanisms of dissolved or undissolved redox mediators, which are the bottlenecks of the accelerating/inhibitory effects, the fast development, and the more application of dissolved or undissolved redox mediators.…”