English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

The leachability of Pb from natural greek clinoptilolite was investigated according to the standard procedures TCLP/EPA/RCRA (1311), EPA Methods 1310, 1320 and DIN 38414-S4. Through SEM/EDAX analysis it was shown that lead was uniformly loaded onto the particles subjected to acid treatment. Sorption was fast during the first few hours and equilibrium was practically attained after 24 h. pH was the dominant factor affecting leaching and for values 3 and higher less than 1% of the metal was leached out while at pH=1 up to 20% of the lead initially present on the solid was leached out. At 1.5 and 2, lead was re-adsorbed after initial leaching. % leaching after 24h was found to increase with increasing initial load (17 to 44% for 15 to100 mgPb/gclin). Agitation rate (50-180 rpm) and particle size (1.4-2 mm and 5-6 mm) did not affect leaching. Higher temperature (25-40 C) resulted in increased leaching rates. Despite the limited number of data, leaching seems to follow third-order kinetics. Finally, exposure to acid conditions increased markedly the specific surface (from 35.1 to 79.4 m g) and lowered the average pore diameter (from 80.8 to 42.9 Å) of the clinoptilolite particles.

Leaching of lead from clinoptilolite at acidic conditions