Uncertainty analysis of Hydraulic Boundary Conditions of the Wadden Sea: Phase 1 of activity 2.3

The goal of the uncertainty analyses within the SBW Wadden Sea project is to find out which accuracy in HBC can be achieved, given the current state of scientific knowledge and technical instruments. Furthermore, we wish to quantify the contribution of the SWAN model and other components to the overall uncertainty in HBC. In order to answer these and related questions we first need to identify and quantify all the possible sources of uncertainty in the HBC calculation. This report gives an overview of the sources of uncertainty that contribute to the overall uncertainty of the HBC in the Wadden Sea. Most of the uncertainties can only be quantified roughly, for example by an estimate of the bandwidth or variance. For the present study this is sufficient. The next step is to analyse how the sources of uncertainty propagate in the resulting HBCs. This report gives a specification of the calculations that are expected to give insight in the error propagation of the relevant sources of uncertainty. The calculations themselves will be done in the second half of 2007 and the results will be reported in a follow-up document.SB

A five-stage treatment train for water recovery from urine and shower water for long-term human Space missions

Long-term human Space missions will rely on regenerative life support as resupply of water, oxygen and food comes with constraints. The International Space Station (ISS) relies on an evaporation/condensation system to recover 74–85% of the water in urine, yet suffers from repetitive scaling and biofouling while employing hazardous chemicals. In this study, an alternative non-sanitary five-stage treatment train for one “astronaut” was integrated through a sophisticated monitoring and control system. This so-called Water Treatment Unit Breadboard (WTUB) successfully treated urine (1.2-L-d−1) with crystallisation, COD-removal, ammonification, nitrification and electrodialysis, before it was mixed with shower water (3.4-L-d−1). Subsequently, ceramic nanofiltration and single-pass flat-sheet RO were used. A four-months proof-of-concept period yielded: (i) chemical water quality meeting the hygienic standards of the European Space Agency, (ii) a 87-±-5% permeate recovery with an estimated theoretical primary energy requirement of 0.2-kWhp-L−1, (iii) reduced scaling potential without anti-scalant addition and (iv) and a significant biological reduction in biofouling potential resulted in stable but biofouling-limited RO permeability of 0.5 L-m−2-h−1-bar−1. Estimated mass breakeven dates and a comparison with the ISS Water Recovery System for a hypothetical Mars transit mission show that WTUB is a promising biological membrane-based alternative to heat-based systems for manned Space missions.Sanitary Engineerin