Modeling and Simulating a Novel Biohydrogen Production Technology as an Integrated Part of a Municipal Wastewater Treatment Plant

A series of mathematical models and simulations was developed and performed using BioWin software suit in order to determine the suitability of implementing a biohydrogen production technology in an existing wastewater treatment plant. The evaluation of the performance of these approach was based on biohydrogen yield and effluent quality. The simulations show high biohydrogen production rates, with picks during the summer months, while most of the effluent environmental parameters remain at the same or even lower levels compared with the currently used technology

Vulvar melanoma presenting as postmenopausal bleeding: A case report

Primary melanomas of the vulva are extremely rare, creating obstacles in the differential diagnosis of other epithelial and non-epithelial malignancies. Due to their rarity, there are only approximately 250 cases reported in the current literature. Vulvar melanomas tend to relapse locally, as well as develop locoregional and distant metastasis through lymph node and haematic dissemination. The authors describe a case of an 84-year-old Caucasian female patient, presenting with postmenopausal bleeding, consistent with primary vulvar melanoma cause, which was successfully diagnosed and treated accordingly

Selenite Removal from Aqueous Solution Using Silica–Iron Oxide Nanocomposite Adsorbents

In recent years, during industrial development, the expanding discharge of harmful metallic ions from different industrial wastes (such as arsenic, barium, cadmium, chromium, copper, lead, mercury, nickel, selenium, silver, or zinc) into different water bodies has caused serious concern, with one of the problematic elements being represented by selenium (Se) ions. Selenium represents an essential microelement for human life and plays a vital role in human metabolism. In the human body, this element acts as a powerful antioxidant, being able to reduce the risk of the development of some cancers. Selenium is distributed in the environment in the form of selenate (SeO42–) and selenite (SeO32–), which are the result of natural/anthropogenic activities. Experimental data proved that both forms present some toxicity. In this context, in the last decade, only several studies regarding selenium’s removal from aqueous solutions have been conducted. Therefore, in the present study, we aim to use the sol–gel synthesis method to prepare a nanocomposite adsorbent material starting from sodium fluoride, silica, and iron oxide matrices (SiO2/Fe(acac)3/NaF), and to further test it for selenite adsorption. After preparation, the adsorbent material was characterized by scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDX). The mechanism associated with the selenium adsorption process has been established based on kinetic, thermodynamic, and equilibrium studies. Pseudo second order is the kinetic model that best describes the obtained experimental data. Also, from the intraparticle diffusion study, it was observed that with increasing temperature the value of the diffusion constant, Kdiff, also increases. Sips isotherm was found to best describe the experimental data obtained, the maximum adsorption capacity being ~6.00 mg Se(IV) per g of adsorbent material. From a thermodynamic point of view, parameters such as ΔG0, ΔH0, and ΔS0 were evaluated, proving that the process studied is a physical one