Wet oxidation of domestic sludge and process integration: the Mineralis process

Wet oxidation (WO) in subcritical conditions is a new alternative to usual routes for sewage sludge treatment that complies with environmental standards. This paper presents tests carried out using a batch reactor and continuous pilot and industrial units, treating municipal sewage sludge. The main products after oxidation are CO2, water, VFA and ammonia. The results highlight the considerable influence of the treatment temperature and of the type of sewage sludge which is treated. At temperatures around 240 degrees C, VFA fraction present in WO supernatant is limited to 50% because of the presence of non-degraded fatty compounds and surfactants. Moreover, the COD reduction is limited to 70%. On the contrary, at 300 degrees C, COD removal efficiencies greater than 80% are achieved without any catalyst addition and, in addition, only highly biodegradable compounds remain in the oxidised liquor. In order to treat the residual ammonia nitrogen by biological processes, it is therefore necessary to obtain a VFA fraction as high as possible for achieving denitrification and then to operate the WO process at high temperature and without catalyst addition.

Effects of nutrient intake on growth, insulin-like growth factors, and their binding proteins in a Laron-type dwarf

In Laron-type dwarfism, a basal growth rate independent of GH and insulin-like growth factor-I (IGF-I) is maintained. This represents a unique model to further assess the relationship between growth and nutritional status. In a child aged 3 yr, 7 months with severe anorexia, growth was followed in relation to his caloric intake. While receiving 496 Cal/day with 11.6 g/day protein, he grew at a rate of 2 cm/yr (period I). The mean plasma IGF-I level was below 0.07 U/mL, insulin was 3.8 +/- 0.2 microU/mL, and blood glucose was 2.9 +/- 0.3 mM/L. During moderate hyperalimentation with 1280 Cal/day and 38.3 g/day protein (period II) for 7 months, growth rate increased to 9 cm/yr with no significant change in plasma IGF-I and persistence of relative hypoinsulinemia (low response to oral glucose tolerance test). IGF-binding proteins, analyzed by Western ligand blotting, showed that 41.5- and 38.5-kilodalton forms, which were initially low, increased to form a pattern similar to that observed in hypopituitarism. These results suggest that catch-up growth did not require normal circulating GH and/or IGF-I activity. Therefore, nutrition contributes to catch-up growth and achievement of potential statural growth by a distinct cellular effect.

[Circulating somatomedin activity and growth hormone secretion. Changes during late diagnosed celiac disease and effects of treatment]

Sixteen children, aged 5-19 years with late diagnosed coeliac disease who presented with significant growth delay were studied. Plasma somatomedin was decreased in all patients (mean 0.28 +/- 0.1) but the circulating growth hormone levels were normal in 12 patients. No inhibitory activity could be detected. Somatomedin activity was partially corrected in six patients who were re-examined after 3 months on a gluten free diet. This suggests that low somatomedin levels may be the result of the nutritional abnormalities during the active phase of the disease.