2.2. Aging treatments
On the basis of our preliminary investigation, the application
rates of bamboo biochar were set at 0.1% and 0.5% (w/w) of soil
weight. Soils were mixed with biochars using a soil mixer and were
directly used in the sorption and desorption experiments. An additional
set of samples, after adjusting the water content of soil to
about 70% of maximum water-holding capacity, were equilibrated
at 25 ± 1 C for 30 d to evaluate the effect of aging. The samples
were checked daily for water loss by weighing, and appropriate
amount of deionized water was added to compensate for water
loss when required. Other well-mixed samples were incubated
under the same conditions and aging time, and added to compensate
for water loss every 10 d (alternating wet and dry).