Nickel-iron-driven heterogenous bio-electro-fenton process for the degradation of methylparaben.

Discharge of emerging contaminants such as parabens in natural water bodies is a grievous concern. Among parabens, methylparaben (MP) is most prevalent due to its extensive usage in personal care and food products and has been purported to trigger hormonal-related diseases. In this regard, the bio-electro-Fenton (BEF) process garners attention for remediating refractory compounds because of its ability to generate in situ hydroxyl radicals (•OH) utilising the energy harvested from electroactive microorganisms. In the present investigation, a Ni-Fe-driven heterogenous BEF system (BEF-MFC) was used to degrade MP from different matrices. At neutral catholyte pH, 99.54 ± 0.22% of MP was removed from an initial concentration of 10 mg/L in 240 min of retention time with an estimated treatment cost of about 1.01 $/m3. The removal rate ameliorated when the catholyte pH was dropped to 3.0 and by imposing an external voltage of 0.5 V, requiring just 120 min to achieve comparable MP removal efficiencies. However, catalyst leaching was higher at acidic pH (leaching of Fe ions = 0.44 mg/L and Ni ions = 0.06 mg/L) and applying external voltage increased the treatment cost slightly to 1.08 $/m3. Further, treatment of 10 mg/L MP-spiked real wastewater at pH of 7.0 with the BEF-MFC attained 85.70 ± 3.30% and 56.50 ± 1.70% reduction in MP and total organic carbon, respectively, in 240 min. In addition, a maximum power density of 205.90 ± 2.27 mW/cm2 was harvested in the BEF-MFC; thus, portraying the dual benefit of Ni-Fe heterogeneous catalyst. Even though, Ni-Fe performed reasonably well as Fenton-cum-cathode catalyst, future endeavours should be poised to fine-tune catalysts to accelerate H2O2 and •OH generation, which will reinforce the scalability of this system.

A filamentous trio.

Opportunistic infections caused by fungi and unusual bacteria are predominantly encountered in the setting of immunosuppressed host. Co-infections with multiple such organisms can pose multiple challenges even to the astute clinician from establishing the diagnosis to drug interactions during treatment of such infections. We hereby present one such case of a triple opportunistic infection in an immunocompetent host and the difficulties faced in the therapeutic decision making.

A 51-Year-Old Woman With Pellets in the Sputum.

CASE PRESENTATION: A 51-year-old woman with no comorbidities presented with a 3-month history of cough with mucopurulent expectoration and intermittent fever. Over the past 1 month, she complained of streaky hemoptysis and gave history of expectorating "whitish pellets" in the sputum on two occasions. She had developed progressive breathlessness for a week prior to presentation to our hospital. There was no history of chest pain or loss of weight or appetite. She was a nonsmoker and did not consume alcohol. She had received multiple courses of antibiotics at another center with no relief of symptoms.