Correlation of wood-based components and dewatering properties of waste activated sludge from pulp and paper industry.

Large amounts of wet sludge are produced annually in municipal and industrial wastewater treatment. Already in pulp and paper industry, more than ten million tons of primary sludge, waste activated sludge, and de-inking sludge is generated. Waste activated sludge contains large quantities of bound water, which is difficult to dewater. Low water content would be a matter of high calorific value in incineration but it also has effects on the volume and the quality of the matter to be handled in sludge disposal. In this research waste activated sludges from different pulp and paper mills were chemically characterised and dewatered. Correlations of chemical composition and dewatering properties were determined using multivariate analysis. Chemical characterisation included basic sludge analysis, elementary analysis and analysis of wood-based components, such as hemicelluloses and lignin-derived material. Dewatering properties were determined using measurements of dry solids content, flux and flocculant dosage. The effects of different variables varied according to the response concerned. The variables which were significant regarding cake DS increase in filtration or centrifugation and flocculant dosage needed in filtration were different from those which were significant regarding flux.

Respiratory symptoms, bronchial hyper-responsiveness, and eosinophilic airway inflammation in patients with moderate-to-severe atopic dermatitis.

BACKGROUND: Patients with atopic dermatitis (AD) often have symptoms suggestive of asthma or rhinitis. The prevalence and signs of respiratory disease in AD patients have been studied to a limited extent. OBJECTIVES: To assess the prevalence and clustering of respiratory symptoms, bronchial hyper-responsiveness (BHR), and eosinophilic airway inflammation in patients with moderate-to-severe AD. METHODS: Eighty-six consecutive patients with moderate-to-severe AD and 49 randomly selected control subjects without AD were studied by questionnaire, flow volume spirometry, histamine challenge to detect BHR, induced sputum test to detect eosinophilic airway inflammation, and skin prick tests (SPTs) and total serum immunoglobulin (Ig)E measurements to detect atopy. RESULTS: The patients with AD showed increased risk of physician-diagnosed asthma (36% vs. 2%, odds ratio (OR) 10.1, confidence interval (CI) 1.3-79.7, P=0.03), physician-diagnosed allergic rhinitis (AR) (45% vs. 6%, OR 4.5, CI 1.2-16.7, P=0.02), BHR (51% vs. 10%, OR 5.5, CI 1.5-20.1, P=0.01), and sputum eosinophilia (81% vs. 11%, OR 76.1, CI 9.3-623.5, P<0.0001) compared with the control subjects. In AD patients, elevated s-IgE and positive SPTs were associated with the occurrence of physician-diagnosed asthma and AR, BHR, and the presence of sputum eosinophilia. CONCLUSIONS: BHR and eosinophilic airway inflammation are more common in patients with AD than in control subjects. The highest prevalences were seen in patients with AD who were SPT positive and had high IgE levels. Longitudinal studies are needed to assess the outcome of patients with signs of airway disease, in order to identify those who need early initiation of asthma treatment.

Effects of 1-year intermittent treatment with topical tacrolimus monotherapy on skin collagen synthesis in patients with atopic dermatitis.

BACKGROUND: Topical corticosteroids decrease collagen synthesis during short-term treatment and can induce skin atrophy when applied over the long term. In contrast, short-term tacrolimus ointment therapy does not affect collagen synthesis. OBJECTIVES: Our aim was to evaluate the long-term effects of 0.1% tacrolimus ointment on collagen synthesis and on skin thickness in adults with moderate to severe atopic dermatitis (AD) and to compare the findings with the effects of conventional steroid-based therapy. METHODS: Fifty-six patients with AD were treated with 0.1% tacrolimus ointment in a 1-year, open-label, prospective clinical trial. Thirty-six patients with AD applied conventional steroid-based therapy and 27 healthy subjects were recruited as controls. The primary endpoint was the change in levels of procollagen propeptides I and III measured by radioimmunoassay between baseline and month 12. Additional endpoints included the change in skin thickness measured by ultrasound between baseline and month 12. RESULTS: Procollagen propeptide baseline values were significantly lower in the group to be treated with tacrolimus ointment than in healthy controls. One-year treatment with tacrolimus ointment was associated with an increase in collagen synthesis; the median increase in combined procollagen propeptide levels was 272 micro g L-1 (+ 140.9%, P < 0.001) and was accompanied by a significant increase in skin thickness. In three patients with visible skin atrophy, this condition ameliorated. Corticosteroid-based therapy had no significant effect on collagen synthesis; the median increase in combined procollagen propeptide levels was 11 micro g L-1 (+ 3.9%). A significant reduction in skin thickness was demonstrated. CONCLUSIONS: Long-term tacrolimus ointment therapy in patients with AD is nonatrophogenic and reverses corticosteroid-induced skin atrophy.