Characterization of Phosphorus in Sludge Extracts Using Phosphorus‐31 Nuclear Magnetic Resonance Spectroscopy

Abstract

Nuclear magnetic resonance spectroscopy (31P NMR) was used to characterize the phosphorus (P) extracted from selected municipal sewage sludges. Aqueous and nonaqueous extraction schemes were studied. The trichloroacetic acid/KOH two‐step extraction and the 0.5 M NaOH extraction were effective in recovering P from sludges. It was found that the P distribution pattern is sludges was affected by the sludge digestion processes. Almost all of the P in anaerobically digested sludges was inorganic. In the waste‐activated sludge and aerobically digested sludges, more than 50% of the total P was present as P‐monoesters and P‐diesters. Several experiments were conducted to confirm P‐diester peak assignment. Incubation of the sludge with ribonuclease caused a decrease of the peak in the P‐diester region, indicating that at least a part of the P‐diesters is in the form of RNA. Results of a dialysis experiment appeared to indicate that P‐diesters were broken down from the molecular weight >1000 material to their lower molecular weight components during sludge digestion. The peaks appearing in the 31P NMR spectra of sludge‐borne phospholipids were tentatively assigned to phosphatidylcholine, phosphatidylserine, phosphatidylethanolamine, and phosphatidylglycerol or diphosphatidylglycerol.

Phytate as a novel phosphorus-specific paleo-indicator in aquatic sediments

“…Of the relatively large number of studies that have determined the phosphorus composition of sewage samples, only Cosgrove (1973) specifically measured phytate, although aerobicallydigested sewage is rich in phosphate monoesters, which almost certainly include some phytate (e.g. Hinedi et al 1989;Smith et al 2006).…”

Nutrient transfer by runoff from sewage sludge amended soil under simulated rainfall

“…2. Actually, after sludge spreading, mineral forms of phosphorus are likely to link to iron or aluminium present in soil (Chang et al, 1983), while organic forms are rapidly hydrolysed, both in acid or basic soils (Hinedi et al, 1989). Most sludges induce a decrease in the binding capacity of soil to phosphate ions, as soon as they are incorporated into soil, but it is not the case for limed sludges, which lead to an increase of this binding capacity.…”

Nitrogen and Phosphorus Availability Following Topsoil Application of Mineral and Organomineral Fertilisers (OMF)

“…With regards to the phosphorus present in biosolids, EC (2003) stated that a small amount of organic-P in the form of organic phosphates, generally not exceeding 6% (w w -1 ), may be found in sludges. This organic-P can contain organic-P species in the form of orthophosphate, pyrophosphate and polyphosphate (Hinedi et al 1989;Cade-Menun and Preston, 1996;Smith et al, 2006). Although the organic-P in the OMF 15 was not quantified for this experiment, to some extent, it could have contributed to increase marginally soil extractable-P levels in OMF 15 -amended soils compared with the unfertilised controls.…”