Leaching of arsenic from brick manufactured from arsenic and iron sludge has been investigated in this study. TCLP result shows that leached metal concentrations are far below the regulated TCLP limits and the quantities of metal leached from sludge are less than those from dried sludge. The results of Atterberg limits tests of moulded sludge-clay mixtures indicated that both plastic index and ...

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...

The potential ecological and human health risk related with urban street dust from urban areas of Tianjin, China was quantitatively analyzed using the method of toxicity characteristic leaching procedure (TCLP) and simple bioaccessibility extraction test (SBET). In the study, Hakason index, Nemerow index (P), the hazard index (HI) and the cancer risk index (RI) were calculated to assess the pot...

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....

In this paper, we describe TCLP, a Temporal Causal Link Planner which takes into account the duration of actions and accepts disjunctive temporal relations, while still using the principles of traditional planners which assume actions are instantaneous. We have defined a model of action with duration, and translate any temporal disjunctive relation between 2 actions with duration into a set of ...

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...

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 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 ...

Arsenic leachability in water treatment adsorbents was studied using batch leaching tests, surface complexation modeling and extended X-ray absorption fine structure (EXAFS) spectroscopy. Spent adsorbents were collected from five pilot-scale filters that were tested for removal of arsenic from groundwater in Southern New Jersey. The spent media included granular ferric hydroxide (GFH), granular...

A long-term field-scale demonstration project on the feasibility of using P to immobilize Pb in a Pb-contaminated urban soil was conducted. Phosphate was applied at an average rate of 3040 mg Pykg soil based on a PyPb molar ration of 4.0, with four treatments: T , no P application; T , H PO only; T , 1y2 H PO q1y2 CaH PO ; and T , 0 1 3 4 2 3 4 2 4 3 1y2 H PO q1y2 phosphate rock. Soil samples w...