Abstract
Abstract Solutions of 0.1M and 0.25M potassium hydroxide (KOH) were used to extract the humic substances from two different types of peat (sphagnum and Carex) at 20, 50 and 80°C. The effects of temperature on the yield of humic and fulvic acids (HA and FA) and on the characteristics of the former were investigated. The highest extraction yields were obtained at the two higher temperatures and by using the most concentrated alkali solution. The higher temperatures resulted in a decrease of the HA/FA ratio in the sphagnum peat although the opposite generally occurred with the Carex peat. As shown by chemical analyses and gel permeation chromatography, the HA released from sphagnum by hot KOH solutions exhibited less oxidized molecules, a lower content of functional groups and larger molecular size than it did at room temperature; whereas the characteristics of the HA released from Carex peat by heat depended on both the alkali concentration and the temperature employed for the extraction.
Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
