Biosolids recycling: Nitrogen management and soil ecology

Abstract

Cogger, C. G., Forge, T. A. and Neilsen, G. H. 2006. Biosolids recycling: Nitrogen management and soil ecology. Can. J. Soil Sci. 86: 613-620. Biosolids are municipal wastewater treatment solids that meet regulatory standards for land application. Most biosolids are a rich source of N, P, and micronutrients. Although the use of biosolids on food crops remains controversial in the public eye, decades of research have led to the development of regulations for the safe and beneficial use of biosolids in agriculture. Emerging areas of research include biosolids in commercial and home horticulture, the fate of pathogens and organics in biosolids, the use of biosolids in the remediation of contaminated sites, and biosolids effects on soil ecology. Nutrient management remains the most critical day-to-day issue for land application of biosolids. Recent research on plant-available nitrogen (PAN) in biosolids has found that N availability is similar over a range of biosolids processing types, and that growing-season climate is a key factor affecting available N. Regionally based predictions of PAN have been developed for the United States, and could be extended into Canada. Relatively little is known about the effects of biosolids applications on soil ecology, but soil nematodes offer an opportunity to evaluate the structure and function of the soil ecosystem following biosolids applications. We have studied responses of nematode communities to application of municipal biosolids and composts, in forage production systems and orchards. Both types of amendments increased the abundance of enrichment opportunists, for up to 3 yr after single applications. These data on the persistence of increased enrichment opportunists have provided insight into the longevity of amendment-induced enhancement of biological activity and nutrient cycling. Cumulative biosolids applications of 90 Mg ha -1 have caused reductions in abundance of pollutant-sensitive Dorylaimida. The extent to which this change is the result of metal or nutrient loading is unclear and deserves more detailed study. On appelle « biosolides » les solides résultant de l'épuration des eaux usées par les municipalités et respectant les normes réglementaires en vue de leur application sur les terres. La plupart des biosolides sont riches en N, en P et en oligoélé-ments. Bien que la fertilisation des cultures vivrières par les biosolides continue de soulever la controverse au sein de la population, des dizaines d'années de recherche ont abouti à l'élaboration de règlements qui rendent cet usage aussi inoffensif que bénéfique. Parmi les nouveaux sujets de recherche, il faut mentionner l'usage des biosolides en horticulture commerciale et domestique, le sort des microorganismes pathogènes et de la matière organique dans les biosolides, la restauration des sites contaminés au moyen des biosolides et l'incidence des biosolides sur l'écologie du sol. La gestion des éléments nutritifs demeure la principale difficulté quotidienne liée à l'application des biosolides sur les terres....

Influence of pyrolysis temperature on production and nutrient properties of wastewater sludge biochar

“…Potassium was found to increase in concentration with increasing temperature mainly because of the inorganic association of potassium with the wastewater sludge. Biosolids commonly contain small amounts of K (0.1e0.6%) as indicated previously by Cogger et al (2006). Table 3 shows that total concentration of the other nutrient elements present in the wastewater sludge and sludge biochar.…”

The role of organic amendments in soil reclamation: A review

“…However, decreasing landfill space has become a societal concern and an environmental issue for many cities, with the result that many of these materials are now land applied. Cogger et al (2006) reported that approximately 60% of biosolids produced in Canada and the United States is recycled through land application. In 2005, Metro Vancouver applied Â15000 Mg (dry wt.)…”

“…(Cogger et al 2006), while paper mill sludge generated in Quebec alone was estimated at Â2 Tg wet wt. in 2002 (Camberato et al 2006).…”

Moisture Effects on Nitrogen Availability in Municipal Biosolids from End-of-Life Municipal Lagoons

“…Nitrogen mineralization in biosolids is influenced by biosolids type and properties, the wastewater treatment method used to generate the biosolids, and the type and length of the stabilization process used (Cogger et al, 2006; Corrêa et al, 2012). Generally, N min has been found to be greater in aerobically digested than in anaerobically digested biosolids (Hseu and Huang, 2005).…”