Financial and technical feasibility of distributed advanced technology water treatment systems .

摘要

This dissertation presents a technical and financial analysis of the implementation of advanced technology treatment units strategically located within water distribution networks. Such units would serve to provide supplemental water treatment to account for water quality degradation occurring within water distribution networks and levels of overall treatment greater than those provided by conventional central treatment systems.; Disinfection by-product (DBP) formation is used as a representative water quality degradation parameter posing risk accumulation in a distribution network. A linear DBP formation model is employed to predict exposure within a hypothetical water utility service population. The costs of upgrading centralized treatment facilities to meet DBP water quality standards are estimated and then apportioned over the fraction of residential service population receiving water degraded below required quality levels. In this way an equivalent or "breakeven" cost for the alternative approach of installing distributed treatment units to meet required quality levels for the entire population is estimated. For a range of different service populations, such costs are determined to range from {dollar}3,500 to {dollar}8,000 per unit. A sensitivity analysis of the impacts of various network parameters on breakeven costs reveals the existence of singularities---sudden shifts in optimal technology selection---resulting from relatively small variations in required treatment levels.; An analytical hierarchical process is used to select the initial treatment technology to be developed for the distributed treatment unit. Adsorptive media (e.g., granular activated carbon) is selected for initial feasibility investigation over separation and destruction technologies. Relevant ancillary requirements, e.g. remote monitoring and control, are delineated and a framework for functional analysis and technology selection is provided for both primary treatment method and ancillary requirements.; Treatment scenarios using a combination of both central and distributed technologies are examined. For any system in which risk accumulates after central treatment an arbitrary risk limit is met at minimum cost by employing specifically designed combinations of central and distributed treatment technologies. The approach described applies to both evolving water supply infrastructures (e.g., developing regions of the world) or the upgrading of existing infrastructures for expansion and/or advanced levels of water quality protection (e.g., developed nations).