Dataset Advanced modelling to determine free ammonia concentrations during (hyper-)thermophilic anaerobic digestion in high strength wastewaters

Experimental batch data belonging to the following publication: Advanced modelling to determine free ammonia concentrations during (hyper-)thermophilic anaerobic digestion in high strength wastewaters, Journal of Environmental Chemical Engineering, 2021, 9(6), 106724, https://doi.org/10.1016/j.jece.2021.10672

Advanced modelling to determine free ammonia concentrations during (hyper-)thermophilic anaerobic digestion in high strength wastewaters

Anaerobic digestion is an attractive treatment technology for concentrated waste streams. However, high ammonia concentrations cause inhibition of methanogenesis, especially when operated at elevated temperatures like (hyper-)thermophilic (55 and 70 °C) anaerobic digestion. These emerging (hyper-)thermophilic technologies are beneficial due to high conversion rates and pathogen removal, but are more susceptible for ammonia toxicity as consequence of a temperature-induced pKa shift. Determination of NH3-N (free ammonia nitrogen (FAN); toxic form) concentrations is conventionally based on an equilibrium model and the total ammonia nitrogen concentration (TAN). However, the conventional equilibrium model overestimates the FAN concentration and therefore we developed an Ionic Activity Model which takes the ionic strength and organic matter interactions into account. The difference between the two models could mainly be attributed to the high ionic strength of the waste stream, whereas interactions with organic matter had a smaller effect. Based on this Ionic Activity Model and batch experiments at hyper-thermophilic conditions, we found that acetoclastic methanogenesis was completely inhibited at FAN concentrations exceeding 588 mg/L, whereas hydrogenotrophic methanogenesis could produce methane up to 925 mg/L. During thermophilic and hyper-thermophilic black water treatment, the ionic strength and organic matter interactions resulted in NH3 concentrations below the inhibitory threshold

Dataset Advanced modelling to determine free ammonia concentrations during (hyper-)thermophilic anaerobic digestion in high strength wastewaters

Experimental batch data belonging to the following publication: Advanced modelling to determine free ammonia concentrations during (hyper-)thermophilic anaerobic digestion in high strength wastewaters, Journal of Environmental Chemical Engineering, 2021, 9(6), 106724, https://doi.org/10.1016/j.jece.2021.10672

Oral contraceptives and rheumatoid arthritis : Further evidence for a preventive effect

To investigate a reported negative association between the use of oral contraceptives (OC) and the development of rheumatoid arthritis, a case-control study was undertaken to compare the histories of OC use between 228 women with a diagnosis of probable or definite rheumatoid arthritis and 302 women with the diagnosis of soft-tissue rheumatism and/or osteoarthritis. The use of OCs before the onset of joint complaints was acknowledged by 31·1% of the rheumatoid arthritis patients and by 55·6% of the controls. After adjustment for possible confounding variables, the rate ratio for ever use became 0·42 (95% confidence interval 0·27-0·65), while it was 0·40 (0·22-0·72) for ex-users and 0·45(0·28-0·75) for current users. These findings confirm the finding from the Royal College of General Practitioners Oral Contraceptive Study that the incidence rate of rheumatoid arthritis among OC users was halved