Nitrogen production from five thermally-dried biosolids plants was measured in two contrasting soil types and compared with samples of undried digested sludge cake from the same treatment works, using a controlled laboratory incubation-extraction procedure. Inorganic-N was lost from the digested biosolids during hightemperature drying by ammonia volatilisation. Nevertheless, the production of nitrate-N in soil amended with thermally-dried biosolids was similar to, or greater than, conventionally-treated dewatered sludge. The results indicate that thermal conditioning significantly increases the mineralisable organic-N content in digested biosolids. Soil properties had subtle effects on the patterns of nitrogen release, but did not significantly affect the overall accumulation of mineral-N from the biosolids. The results showed that thermally-dried anaerobically-digested biosolids are potentially highly-consistent products and effective replacements for inorganic-N fertiliser in agricultural production.
No abstract
An important requirement in thick, high-porosity scaffolds is to maximise cellular penetration into the interior and avoid necrosis during culture in vitro. Hitherto, reproducible control of the pore structure in nonwoven scaffolds has proved challenging. A new, channelled scaffold manufacturing process is reported based on water jet entanglement of fibres (hydroentangling) around filamentous template to form a coherent scaffold that is subsequently removed. Longitudinally-oriented channels were introduced within the scaffold in controlled proximity using 220 µm diameter cylindrical templates. In this case study, channelled scaffolds composed of poly(l-lactic acid) were manufactured and evaluated in vitro. Environmental scanning electron microscope and µCT (X-ray microtomography) confirmed channel openings in the scaffold cross-section before and after cell culture with human dermal fibroblasts up to 14 weeks. Histology at week 11 indicated that the channels promoted cell penetration and distribution within the scaffold interior. At week 14, cellular matrix deposition was evident in the internal channel walls and the entrances remained unoccluded by cellular matrix suggesting that diffusion conduits for mass transfer of nutrient to the scaffold interior could be maintained.
Developing successful scaffolds requires clinicians to adopt a multidisciplinary approach in order to understand and stimulate the natural bone regeneration process. A variety of natural and synthetic biomaterials, including naturally extracted, chemically functionalised collagen and synthetic Poly(epsilon-caprolactone) (PCL), can be manufactured into fibres, enabling the formation of nonwoven scaffolds. Many different nonwoven architectures and structural features can then be introduced, depending on the manufacturing parameters. This chapter introduces methods for producing scaffolds with appropriate pore sizes by means of electrospinning, and it outlines the opportunities that exist for other nonwoven manufacturing technologies in the development of biomimetic products.Comment: 4 figures, 1 table, Biomedical Textiles for Orthopaedic and Surgical Applications (book) 201
In 1996, Thames Water launched a range of peat‐free compost products based on biosolids. In order to keep up with demand and to maintain the high standards of product quality, the company has investigated higher‐rate composting processes and optimisation of the maturation stage. Agitated‐bay composting systems are the preferred in‐vessel technology for large sludge treatment centres using woodchip as a bulking agent. These automated systems (i) accelerate the composting process, (ii) maximise throughput on a smaller footprint, and (iii) achieve better control of odour emissions. A maturation trial with composted material from the US Filter agitated‐bay system confirmed that a horticultural‐grade product could be attained. Small‐scale maturation trials showed that seeding with mature green waste compost can accelerate nitrification to such a rate that near zero levels of ammonia can be achieved after one month of maturation.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.