Experiments were conducted on arsenic and lead volatility from simulated slags containing either arsenic or lead. Samples were exposed to temperatures up to 900 C and atmospheres that were inert, oxidizing, reducing, or contained hydrogen chloride. Both arsenic and lead deposited within the system during the experiment, requiring a cleaning procedure to remove and capture the metal for measurement. Arsenic or lead volatility increased with increasing treatment time, temperature, and CO concentration. Lead volatility also increased with increasing HC1 concentration. The arsenic volatilized was two orders of magnitude less than lead for the same experimental conditions. The results show that under conditions similarly occurring in a hazardous waste incinerator, arsenic in a slag is relatively involatile, and only a small fraction of either arsenic or lead is volatilized.

Experiments were conducted in a tube furnace on the volatility of arsenic from contaminated kaolin clay. The experimental temperatures ranged from 522 to 1125°C. The gas compositions used were nitrogen, oxygen and nitrogen, carbon monoxide and nitrogen, and hydrogen chloride and nitrogen. At 522°C, 10 to 22% or less of the arsenic volatilized in all experiments. At 1125°C under inert and oxidizing atmospheres, about 40% of the arsenic volatilized. Arsenic volatility was higher for the reducing and the hydrogen chloride-containing atmospheres. At 950°C and residence times of 1 h or longer, 80% or more of the arsenic was lost for both the reducing and the hydrogen-chloride containing atmospheres. At 1125°C, arsenic volatilization ranged from 82 to 92% for the reducing atmosphere and 91 to 98% for the hydrogen chloride-containing atmosphere. The low arsenic volatility in the oxidizing experiments is similar to results in pilot-and full-scale incinerator tests.

No abstract

Saturated hydraulic conductivities K(µm/s) of soils of spodic and argillic horizons were measured in several Florida soils. The soils were Haplaquods, Haplohumods, Glossaqualfs, and Argiaquolls. Two methods of measurement were compared. The core method consistently gave larger hydraulic conductivity values than the piezometer method. The lowest K(µm/s) rates were in argillic horizons. The permeability classification of most soils studied depended upon the measurement method used.

No abstract