Leaching potential of pervious concrete and immobilization of Cu, Pb and Zn using pervious concrete.
J Contam Hydrol
; 161: 35-48, 2014 Jun.
Article
in En
| MEDLINE
| ID: mdl-24748027
ABSTRACT
This paper investigates the leaching potential of pervious concrete and its capacity for immobilizing Cu, Pb and Zn, which are common contaminants in urban runoff. Batch experiments showed that the leachability of Cu, Pb and Zn increased when pH<8. According to PHREEQC equilibrium modeling, the leaching of major ions and trace metals was mainly controlled by the dissolution/precipitation and surface complexation reactions, respectively. A 1-D reactive transport experiment was undertaken to better understand how pervious concrete might function to attenuate contaminant migration. A porous concrete block was sprayed with low pH water (pH=4.3±0.1) for 190 h. The effluent was highly alkaline (pH~10 to 12). In the first 50 h, specific conductance and trace-metal were high but declined towards steady state values. PHREEQC modeling showed that mixing of interstitial alkaline matrix waters with capillary pore water was required in order to produce the observed water chemistry. The interstitial pore solutions seem responsible for the high pH values and relatively high concentrations of trace metals and major cations in the early stages of the experiment. Finally, pervious concrete was sprayed with a synthetic contaminated urban runoff (10 ppb Cu, Pb and Zn) with a pH of 4.3±0.1 for 135 h. It was found that Pb immobilization was greater than either Cu or Zn. Zn is the most mobile among three and also has the highest variation in the observed degree of immobilization.
Key words
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Soil Pollutants
/
Construction Materials
/
Environmental Pollution
Aspects:
Determinantes_sociais_saude
Language:
En
Journal:
J Contam Hydrol
Journal subject:
TOXICOLOGIA
Year:
2014
Document type:
Article