A new, efficient, one-step method for the removal of organic matter from clay-containing sediments

Abstract

For the purpose of clay examination, a new one-step method for the removal of organic matter was developed using sodium peroxodisulphate combined with different buffers such as sodium hydrogen carbonate, disodium hydrogen phosphate and disodium tetraborate. From an early Cretaceous black shale from the Apennines with a high organic carbon content, the <2 gm clay fraction was separated and contained 10.9 wt% organic carbon. To prevent decomposition of the clay layers, the period of oxidation was short (25-60 min) and the pH was kept between 5 and 9.5. Up to 98% of carbon was removed by this method.

Comparison of chemical fractionation methods for isolating stable soil organic carbon pools

“…Since traces of carbonate from the buffer remaining in the sample may interfere with 14 C analysis of Na 2 S 2 O 8 ‐resistant SOC (Mikutta et al , 2005b; v. Lützow et al , 2007), we added 20 ml 0.01 M HCl to the sample dispersed in 20 ml distilled water in order to remove traces of carbonate left after the treatment, as suggested by Meier & Menegatti (1997). After removal of carbonates, the sample was washed until neutral pH and freeze‐dried.…”

Stabilization of organic carbon in chemically separated pools in no-till and meadow soils in Northern Appalachia

“…The filter and residue were washed six times with distilled water. Oxidation of the SOC was achieved by treatment with Na 2 S 2 O 8 (Meier and Menegatti, 1997). Briefly, 0.5 g of ground bulk soil was dispersed in 250 ml of distilled water and allowed to react with 20 g of Na 2 S 2 O 8 , buffered with 22 g NaHCO 3 for 2 days at 80°C.…”

Mixture design and treatment methods for recycling contaminated sediment

“…The addition of coal fly ash led to pozzolanic reaction and formed secondary C-S-H gel that enhanced strength and reduced water absorption [21,22], whereas lime addition raised pH and supplied dissolved calcium to promote C-S-H and CH formation [17]. In addition, various pretreatment methods were potentially useful for removing organic matter and soluble salts from contaminated sediments, including water washing, alkali extraction, thermal decomposition, and chemical oxidation [16,[23][24][25]. Thus, different binder formulations and pretreatment methods were first evaluated.…”