The importance of resource recovery for environmental sustainability of an energy self-sufficient sewage treatment plant

We have applied a state-of-the-art env. sustainability assessment to an energy positive sewage treatment plant, its supply chain and resource recovery: electricity production out of biogas from sludge digestion and the associated stabilized digestate, applied as agricultural fertilizer, production. Prominent aspects of our study are: a holistic environmental impact assessment, measurement of greenhouse gas emissions (including N2O), and accounting for infrastructure, toxicity of metals present in the digestate and replacement of conventional fertilizers and electricity. The impact of latter products is prevented. Overall, the system leads to a prevention of resource extraction from nature and a potential prevention of ecosystem diversity loss (though for some impact categories this cannot be quantified) but it also leads to a damaging effect on human health, mainly via climate change (dominated by N2O) and heavy metal (mainly Zn) toxicity of digestate. Resource recovery plays a crucial role in the environmental sustainability though the assessment methodology needs improvement

The Pine Needle, March 1947

Libraries and archives collect materials from different cultures and time periods to preserve and make available the historical record. As a result, materials such as those presented here may reflect sexist, misogynistic, abusive, racist, or discriminatory attitudes or actions that some may find disturbing, harmful, or difficult to view. Both a humor and literary magazine, The Pine Needle was a University of Maine student-produced periodical that began publication in the fall of 1946, the first post-World War II semester that saw GIs returning to campus. The Needle reflected an edginess and rebellion not found in previous UMaine student publications. While past student publications relied on euphemisms for alcohol and dating on campus, The Needle overtly sexualized co-eds and discussed the use of drugs, tobacco, and alcohol by students who experienced war. Cover art for this issue depicts a pen-and-ink illustration by Lloyd Shapleigh (1924-2008), of barefoot man lounging under a tree, reading an issue of New Yorker magazine with a corked jug beside his right elbow. Lloyd P. Shapleigh, Jr. was born in Bangor, Maine, graduating from high school in 1942 before joining the Army Air Corps during World War II where he qualified as MOE 867-Pathfinder technician and served as a ground crew chief with the 458 Bomb Group (H), 2nd Air Division, 8th Air Force. After the war, Shapleigh used the G.I. Bill to earn Bachelor\u27s Degrees at the University of Maine and Rhode Island School of Design. Shapleigh eventually joined the industrial design team at Whirlpool where, in 1966, he conducted research testing the feasibility of household trash compaction. The trash compactor became the first new, major household appliance released by the Whirlpool corporation since before the war

Modeling the decay of nitrite oxidizing bacteria under different reduction potential conditions

[EN] Autotrophic growth and decay rates of ammonium and nitrite oxidizing bacteria (AOB and NOB, respectively) have a significant impact on the design and on the process performance of wastewater treatment systems where nitrification occurs. Literature data on the separate decay rates of AOB and NOB is scarce and inconsistent. In this study, batch experiments based on respirometric techniques were conducted to determine the NOB decay rates under different oxidation-reduction potential conditions, in order to widen the understanding of nitrite dynamics. The decay rate measured under anoxic conditions was 85% lower than under aerobic conditions, whereas under anaerobic conditions the decay rate reduction was 92%. A design and simulation tool was used to assess the impact of applying these results in differentiated areas of an activated sludge system. Simulations show a greater impact for systems with a sludge retention time under 10 days, for which up to a 16-fold increase in NOB biomass concentration and up to 86% and 80% reductions in ammonium and nitrite concentrations in the effluent were calculated. Therefore, this work demonstrates that considering different decay rates for autotrophic biomass under different ORP conditions avoids underestimating system performance and over dimensioning new activated sludge schemes.This research project has been supported by the Spanish Ministry of Economy, Industry and Competitiveness (MINECO,project CTM2017-86751-C2), whose support is gratefully acknowledged.Ruiz Martinez, A.; Claros Bedoya, JA.; Serralta Sevilla, J.; Bouzas Blanco, A.; Ferrer, J. (2018). Modeling the decay of nitrite oxidizing bacteria under different reduction potential conditions. Process Biochemistry. 71:159-165. https://doi.org/10.1016/j.procbio.2018.05.021S1591657