Optimization of Polymer Dosing for Improved Belt Press Performance in Wastewater Treatment Plants

A factorial trial approach was used to determine the relationship between process parameters and filtrate suspended solids, solids capture, cake solids, and yield stress. The work was conducted in a large-scale wastewater treatment plant where there is sludge thickening on a linear screen before filter press. The work demonstrated that there is a relationship between filtrate suspended solids, the rheology of sludge, and the optimum dewatering of the filter belt press. A relationship between the yield stress of the sludge on the BFP and the filtrate suspended solids was found. The sludge flow rate was the most influential parameter on the filtrate suspended solids and solids capture as well as yield stress. The linear screen speed was a significant main parameter for cake solids. The results showed clearly that the interaction between sludge flow rate and either polymer dosing rate or polymer concentration was consistently more significant than polymer concentration and polymer dosing rate individually. An important outcome from this work is that it shows that changes in polymer concentration rather than polymer dosing rate are more important for optimization and control

Portal vein thrombosis in patients with cirrhosis

Portal vein thrombosis (PVT) is frequent in patients with liver cirrhosis and possible severe complications such as mesenteric ischemia are rare, but can be life-threatening. However, different aspects of clinical relevance, diagnosis and management of PVT are still areas of uncertainty and investigation in international guidelines. In this article, we elaborate on PVT classification, geographical differences in clinical presentation and standards of diagnosis, and briefly on the current pathophysiological understanding and risk factors. This review considers and highlights the pitfalls of the various treatment approaches and prophylactic treatments. Finally, we review the controversial issue of clinical impact of PVT on prognosis, especially considering liver transplantation and future perspectives