Hydrogenotrophic biogas upgrading integrated into WWTPs: enrichment strategy.

Within the European circular economy roadmap, it is important for wastewater treatment plant (WWTPs) to recover energy and become energy-neutral or -positive. In the last few years, it has become increasingly interesting to boost energy recovery through the biogas upgrading. The aim of this work is to study a rapid hydrogenotrophic methanogenic culture enrichment strategy capable of limiting the organic degradation unbalance and allowing a fast start-up phase of the in situ biogas upgrading reactors, at pilot- or full-scale. The approach was tested with two, plus one control, laboratory-scale continuous stirred tank reactors filled with anaerobic sludge collected from a full-scale WWTP. The experimentation lasted 50 days and was divided into five phases: the anaerobic digestion start-up followed by four H2 injection phases (H2/CO2 ranging from 1:1 to 4:1 on molar basis). Despite a temporary slight increase in the total concentration of volatile fatty acids during phase II (2.56 gCH3COOH·L-1), and in phase III a mild pH increase (anyway, below 7.4) indicating the expected CO2 depletion, the strategy proposed was effective. In the last phase, in the biogas a methane content of about 80% was achieved, thus suggesting that the use of H2/CO2 above the stoichiometric value could further improve the biological biogas upgrading.

Autotrophic nitrogen removal by a two-step SBR process applied to mixed agro-digestate.

The aim of this research was to evaluate the applicability of partial-nitritation/anammox processes for biological N removal from a centrifuge supernatant coming from a full scale anaerobic digester fed on a mixture of piggery manure, poultry manure, and agro-wastes. Stable partial nitritation was achieved at pilot-scale (650L SBR), obtaining a suitable influent for the anammox lab-scale SBR reactor (3L). The anammox lab scale reactor was fed with increasing fractions of the partial nitritation effluent, blended with synthetic wastewater. In the last 100days no dilution was used. The nitrogen loading rate applied to the anammox reactor was 0.5-0.6gNL(-)(1)d(-)(1) and the average nitrogen removal was 91±10%. During the first days of operation with undiluted supernatant, the maximum anammox activity in the SBR decreased, but recovered afterwards, suggesting the ability of the anammox biomass to acclimate to the wastewater. N2O emissions in both reactors were also measured.

[Breast cancer: lonely encounter with fear to the unknown]. / Câncer de mama: encontro solitário com o temor do desconhecido.

This is a qualitative research whose goal is to understand the experiences of women during the process of discovering breast cancer. The study involved eight college women who developed breast cancer, with ages ranging from 30 to 57 years. The comprehension of the studied phenomenon derived from Merleau-Ponty's (1996) phenomenology and to analyze the data it was used the five steps of Giorgi's (1985, 1997) phenomenological method, adding to them a sixth step proposed by Comiotto (1992). From this analysis, emerged two dimensions related to the essence Lonely encounter with the fear f the unknown: from the moment of finding the lump to the crucial moment of diagnosis, and experienced conflicts within the most significant relationships (husband, children and parents).