Biorefinery potential of sustainable municipal wastewater treatment using fast-growing willow.

The use of willow plantations can be a sustainable approach for treating primary municipal wastewater, potentially reducing both the environmental and economic burdens associated with conventional treatment. However, the impact of wastewater irrigation upon the willow biorefinery potential has not yet been established. To investigate this effect, three-year-old field grown willows were harvested from plots kept as either controls or irrigated with primary municipal wastewater effluent at 29.5 million L ha-1 yr-1. Biomass compositional analysis, ionic liquid pretreatment and enzymatic saccharification were assessed and differential abundance of persistent extractable phytochemicals was evaluated using untargeted metabolite profiling. Glucan significantly increased by 8% in wastewater treated trees, arabinose and galactose were significantly decreased by 8 and 29%, respectively, while xylose, mannose and lignin content were unaltered. Ionic liquid pretreatment and enzymatic saccharification efficiencies did not vary significantly, releasing >95% of the cell wall glucose and recovering 35% of the lignin. From a total of 213 phytochemical features, 83 were significantly depleted and 14 were significantly enriched due to wastewater irrigation, including flavonoids and lignan derivatives. Considered alongside increased biomass yield from wastewater irrigation (+200%), lignocellulosic bioenergy yields increased to 8.87 t glucose ha-1 yr-1 and 1.89 t ha-1 yr-1 recovered lignin, while net extractives yields increased to 1.48 t ha-1 yr-1, including phytochemicals of interest. The maintenance of glucose accessibility after low-cost ionic liquid pretreatment is promising evidence that sustainable lignocellulose bioenergy production can complement wastewater treatment. Untargeted metabolite assessment revealed some of the phytochemical toolkit employed by wastewater irrigated willows, including accumulation of flooding and salinity tolerance associated flavonoids glabraoside A and glabrene. The extractable phytochemicals underpin a novel high biomass phenotype in willow and, alongside lignocellulosic yields, could help enhance the economic feasibility of this clean wastewater treatment biotechnology through integration with sustainable biorefinery.

Superior vena cava stent placement: results with the Wallstent endoprosthesis.

PURPOSE: To assess the clinical success and short-term patency of the Wallstent endoprosthesis in the treatment of superior vena cava (SVC) syndrome. MATERIALS AND METHODS: Twenty-one 14-mm-diameter endoprostheses were implanted in 15 patients (mean age, 60 years) treated for SVC syndrome due to malignant compression (n = 14) or postirradiation fibrotic stenosis (n = 1) of the SVC. RESULTS: Immediate technical success was achieved in all patients. Two early complications occurred: retroperitoneal hemorrhage due to venous iliac tear and early stent thrombosis. In the 14 patients without early stent occlusion, stent placement resulted in complete relief of SVC syndrome; clinical success was 93%. SVC syndrome did not recur from 1 to 14 months, until the patient died (n = 11) or until the end of the study (n = 3). Helical CT showed a patent stent in five patients, respectively, at 3, 6, 8, 10, and 11 months. CONCLUSION: SVC stent placement has good clinical results and a high patency rate at short-term follow-up in patients with SVC syndrome.

Renal artery stent placement: long-term results with the Wallstent endoprosthesis.

PURPOSE: To evaluate clinical success and long-term patency of a Wallstent in the renal artery. MATERIALS AND METHODS: Twenty-five Wallstents were placed in 21 patients to treat delayed restenosis after previous balloon angioplasty (n = 13) or inadequate immediate postangioplasty response (n = 8). Indications for angioplasty were hypertension in all patients and renal preservation in seven. Stenosis was atheromatous in 15 patients, involving ostium in seven. RESULTS: Stent placement was successful in all patients. At follow-up angiography (range, 12-60 months), four patients (20%) had stent restenosis. Of these, three had undergone treatment for restenosis after angioplasty and three had ostial lesions. Cumulative primary patency rate was 95%, 85%, and 77% at 7, 9, and 15 months, respectively. Hypertension was cured in three patients and improved in 18. CONCLUSION: Arterial stent placement has good clinical results and high long-term patency rates after conventional renal angiography or delayed restenosis, especially in ostial lesions.