Polymer coatings on nano-sized remediation agents and subsurface heterogeneity will affect their transport, likely in a pH-dependent manner. The effect of pH on the aggregation of polymer-coated nanoscale zerovalent iron (nZVI) and its deposition onto sand and clay (kaolinite) surfaces was studied. nZVI coatings included a high molecular weight (90 kg/mol) strong polyanion, poly(methacrylic aci...

The presence of heavy metals in the industrial effluents has recently been a challenging issue for human health. Efficient removal of heavy metal ions from environment is one of the most important issues from biological and environmental point of view, and many studies have been devoted to investigate the environmental behavior of nanoscale zerovalent iron (NZVI) for the removal of toxic heavy ...

This paper introduces the concept of 'Precision Mining' of metals which can be defined as a process for the selective in situ uptake of a metal from a material or media, with subsequent retrieval and recovery of the target metal. In order to demonstrate this concept nanoscale zerovalent iron (nZVI) was loaded onto diatomaceous earth (DE) and tested for the selective uptake of Cu from acid mine ...

Small-scale and household low-cost technologies to provide water free of arsenic for drinking purposes, suitable for isolated rural and periurban areas not connected to water networks in Latin America are described. Some of them are merely adaptation of conventional technologies already used at large and medium scale, but others are environmentally friendly emerging procedures that use local ma...

Polyelectrolyte coatings significantly increase the mobility of nanoscale zerovalent iron (NZVI) in saturated porous media. The effect can be attributed to improved colloidal stability of NZVI suspensions, decreased adhesion to soil surfaces, or a combination of the two effects. This research explicitly examines how coatings control NZVI adhesion to model soil surfaces. NZVI was coated with thr...

To date, chloroethyne in the environment has been proposed to occur as a reactive intermediate during the reductive dechlorination of tri- and tetrachloroethene with zerovalent metals. Such artificial conditions might possibly be found at organohalide-contaminated sites that are surrounded by remediation barriers made of metallic iron. In this paper, it is shown that the highly reactive chloroe...

Despite keen interest in the development of efficient materials for removal polycyclic aromatic hydrocarbons (PAHs) wastewater, application advanced composite is still unexplored and needs attention. Therefore, this study focused on synthesis oil palm leaves’ waste activated-carbon (OPLAC) nano zerovalent iron (NZVI) at Fe:OPLAC = 1:1 (N-OPLAC-1) 1:2 (N-OPLAC-2). The with enhanced surface prope...

We propose a model molecular wire sensor that can detect zerovalent chromium by a strong increase in conductance when included in a metal-molecule-metal junction. An essential part of the sensor is a paracyclophane unit that binds to the metal atom. The nature and the energies of the molecular orbitals change drastically after the complex is formed, resulting in a 10- to 12-fold increase in con...

The development of slow-release chemical oxidants for sub-surface remediation is a relatively new technology. Our objective was to develop slow-release persulfate-paraffin candles to treat BTEX-contaminated groundwater. Laboratory-scale candles were prepared by heating and mixing Na(2)S(2)O(8) with paraffin in a 2.25 to 1 ratio (w/w), and then pouring the heated mixture into circular molds that...

Subsurface injection of nanoscale zerovalent iron (NZVI) has been used for the in situ remediation of chlorinated solvent plumes and DNAPL source zones. Due to the cost of materials and placement,the efficacy of this approach depends on the NZVI reactivity and longevity, selectivity for the target contaminant relative to nonspecific corrosion to yield H2, and access to the Fe0 in the particles....