Laboratory experiments and modeling studies were performed to investigate the redox transformations of arsenic and iron in water treatment sludge during aging, and to evaluate the impact of those transformations on the leachability of arsenic determined with the U.S. EPA toxicity characteristic leaching procedure (TCLP). When the backwash suspension samples collected from a California surface w...

Abstract In this study, the production of indoor humidity-buffering coatings (IHC-s) from recycling waste silica sludges by using a room-temperature sol-gel method which is simple and energy-efficient route reported. The properties these IHC-s are identified scanning electron microscope, X-ray diffraction, fluorescence spectrometer, laser particle size analyzer, N 2 adsorption-desorption isothe...

Size-reduced samples of southern yellow pine dimensional lumber, each treated with one of five different waterborne chemical preservatives, were leached using 18-h batch leaching tests. The wood preservatives included chromated copper arsenate (CCA), alkaline copper quaternary, copper boron azole, copper citrate, and copper dimethyldithiocarbamate. An unpreserved wood sample was tested as well....

Stabilization was applied as a remediation option for immobilizing lead (Pb) in contaminated mine soil. Four types of waste materials were used stabilizing agents, namely oyster shells (WOS), calcined (COS), natural starfish (NSF), and spent-coffee-grounds-derived biochar (SCGB). The Pb-contaminated soil treated with the agents ranging from 0 to 10 wt% curing period 28 days. toxicity characteri...

The objective of this study is to use the geopolymer technique solidify/stabilize heavy metal contaminated soil. There are over 739,700 square meters heavy-metal-contaminated sites in Taiwan; most soil farmlands. These contaminants can also infiltrate into groundwater and cause more serious pollution problems. This explores possibility using solidify (CS), stabilize metal, produce good mechanic...

Phosphate rock (PR) and phosphoric acid (PA) are an effective combination of P sources for immobilizing Pb in contaminated soils. This column experiment examined the effectiveness of different application methods on Pb immobilization in a contaminated soil. Phosphate was applied at a P/Pb molar ratio of 4 with half as PR and half PA. While PR was mixed with the soil or placed as a layer, aqueou...

The distribution of lead in soil samples collected from both surface (0 to 10 cm) and profile (0 0 to 10 cm, E 11 to 30 cm, Eb 31 to 50 crn, Bw 51 to 100 cm, and C 181 to 200 cm) at a 14-year-old rifle/pistol shooting range located in central Florida were determined using EPA Method 3051a (microwave, HNO/HCI=3:1, v/v). In addition to total lead analysis, Toxicity Characteristic Leaching Procedu...

The application of a catalytic-activated carbon to the solidification/stabilization (S/S) process for immobilization of phenol and 2-chlorophenol and catalytic decomposition was investigated. The effect of the catalytic-activated carbon, in amounts of 0.25-1% (by dry sand wt.), on the leaching of phenol and 2-chlorophenol was studied. H2O2 was added as a source of oxygen in the amounts of 1 or ...