Economic and Life Cycle Assessment of Electrodialysis, Denitrification, and Anammox for Nitrogen Removal in Municipal Wastewater Treatment

Technologies to remove nitrogen from wastewater are employed to preserve drinking water and prevent environmental damage. Nitrification/denitrification and partial nitrification-anammox are two accepted wastewater nitrogen removal techniques for wastewater treatment plants. These processes require energy for aeration and can release fugitive greenhouse gases in the form of nitrous oxide. Electrodialysis could potentially be used as an alternative to remove ammonium from waste streams but previous experimentation has concluded that concentrate flows experience rapid scaling and fouling of membranes. A newly-patented electro dialysis technique, however, uses monovalent-selecting membranes to exceed previous technological limitations with the goal of extracting ammonium ions from sewage for market as ammonium-based fertilizer while limiting scale from poly valent ions. This life cycle assessment compares the three technologies and compiles literature values to attempt to compare the state of the art of municipal nitrogen removal to the new electrodialysis technique, accounting for the offset of Haber Bosch-derived ammonia. Nitrogen removal and recovery by electrodialysis is estimated to carry both lower initial capital costs and lower operation costs than traditional technologies. Electrodialysis is also projected to be environmentally favorable compared to the state of the art, projecting electricity savings similar to anammox and, with the offset of industrial ammonia manufacture, net negative emissions in several environmental categories

BioWin Modeling of CalPrex Phosphorus Recovery from Wastewater Predicts Substantial Nuisance Struvite Reduction

The wastewater treatment industry could benefit from new technologies for the removal and recovery of phosphorus (P). The CalPrex precipitation reactor has the potential to recover P in a readily land-applicable form by treating organic acid digestate with calcium hydroxide to produce brushite. Using data from a pilot-scale reactor at the local Nine Springs Wastewater Treatment Plant in Madison, WI, we modified the plant’s BioWin configuration using BioWin 6.2 to model the CalPrex technology and estimate performance under a variety of conditions. We produced dose/response curves for a range of possible lime dosages to estimate the impact of reagent dosage on the quantity and composition of precipitate produced by the CalPrex reactor and characterize the effects on downstream anaerobic digester performance. CalPrex was found to capture 46% of the plant’s influent P, reducing nuisance struvite precipitates by 57% and biosolid sludge production by 14%. The CalPrex module was also tested in two predesigned plant configurations in the BioWin cabinet with the intention of testing applicability to other configurations and searching for the impacts of CalPrex on treatment train performance. This is the first work simulating a full-scale implementation of CalPrex and the first to model interactions of CalPrex with other treatment processes

Improving BioWin Modeling of Phosphorus Solubilization in Acid-Phase Digesters

BioWin 6.0 does not accurately predict phosphorus (P) speciation in acidogenic anaerobic digesters under default kinetics characterization and parameterization. The accurate modeling of acid-phase digestion is needed to predict the performance of novel nutrient recovery technologies that act on these digester effluents. The main thrust of this work was to identify and correct the causes of inaccurate P partitioning and precipitation within BioWin models of acid-phase digestion reactors. A BioWin configuration including an organic acid digester was parameterized and recalibrated based on the known traits of acid-phase digestion and then validated against a full-scale digester in a municipal wastewater treatment plant. This digester, with pH 5.14 and 61–74% solubilized P, was predicted by BioWin default parameters to have only 27% soluble P and a net formation of P precipitates. Corrections to the polyphosphate-accumulating organism decay, endogenous product decay, hydrolysis rate, and brushite behavior resulted in 67% solubilization with no precipitate formation. Cabinet configurations showed similar behavior when modified to include an acid-phase digester under default parameters, but predictions were similarly amended by our parameter changes. This improved modeling technique should allow operators to effectively characterize acid digesters for their own treatment trains and allow engineers to predict the performance of novel nutrient recovery technologies acting on acidogenic digest

Life cycle assessment of electrodialysis for sidestream nitrogen recovery in municipal wastewater treatment

Nitrogen is removed during municipal wastewater treatment to reduce eutrophication of waterways and preserve drinking water quality. Nitrification-denitrification and sidestream partial nitrification-anammox are state-of-the-art municipal N removal technologies, but they require energy for aeration and can release nitrous oxide as a fugitive greenhouse gas. An emerging sidestream electrodialysis technology is intended to both remove and recover N as ammonium-based fertilizer. This midpoint life cycle assessment compiles literature values to compare the state-of-the-art technologies of municipal wastewater nitrogen removal to the new electrodialysis nitrogen removal and recovery technology, accounting for the offset of Haber-Bosch-derived ammonia. Electrodialysis is projected to be environmentally favorable compared to the state-of-the-art, predicting electricity savings similar to anammox and, with the offset of industrial ammonia manufacture, net negative emissions in five of ten midpoint environmental impact categories, including global warming potential

Reinventing American Protestantism: Christianity in the new millennium

During the past thirty years the American religious landscape has undergone a dramatic change. More and more churches meet in converted warehouses, many have ministers who've never attended a seminary, and congregations are singing songs whose melodies might be heard in bars or nightclubs. Donald E. Miller's provocative examination of these "new paradigm churches" - sometimes called megachurches or postdenominational churches shows how they are reinventing the way Christianity is experienced in the United States today.Drawing on over five years of research and hundreds of interviews, Miller explores three of the movements that have created new paradigm churches: Calvary Chapel, Vineyard Christian Fellowship, and Hope Chapel. Together, these groups have over one thousand congregations and are growing rapidly, attracting large numbers of worshipers who have felt alienated from institutional religion. While attempting to reconnect with first-century Christianity, these churches meet in nonreligious structures and use the medium of contemporary twentieth-century America to spread their message through contemporary forms of worship, Christian rock music, and a variety of support and interest groups.In the first book to examine postdenominational churches in depth, Miller argues that these churches are involved in a second Reformation, one that challenges the bureaucracy and rigidity of mainstream Christianity. The religion of the new millennium, says Miller, will connect people to the sacred by reinventing traditional worship and redefining the institutional forms associated with denominational Christian churches. Nothing less than a transformation of religion in the United States may be taking place, and Miller convincingly demonstrates how "postmodern traditionalists" are at the forefront of this change