The consequences of disposing wastewater in an endorheic wetland in southwest Iran

Click beetles (Coleoptera: Elateridae) of Khuzestan province (Iran): with three new species, Craspedostethus izehensis sp.n., Dicronychus khuzestanicus sp. n. and Gurjevelater catei sp. n

More than 730 specimens of Elateridae were collected in Khuzestan province. Thirty three species belonging to 18 genera and five subfamilies are listed. Three new species, Craspedostethus izehensis sp. n., Dicronychus khuzestanicus sp. n., Gurjevelater catei sp. n. are described, along with the female of Aeoloides iranicus Platia & Gudenzi, 2002. Dicronychus houschkai Platia, 2011 is recorded as a new species to Iran. A distributional map and climate data for each species, along with photographs of habitus and genitalia of eight species are presented.

Impact of methionine on a partial-nitritation biofilter

It has been demonstrated that an anaerobic digestion process cannot attain an efficient removal of several amino acids, with methionine being one of the most persistent of these. Thus, the effect that methionine amino acid has over the partial-nitritation process with fixed-biofilm configuration in terms of performance and bacterial community dynamics has been investigated. With respect to the performance with no addition, 100 mg/L methionine loading decreased ammonium oxidation efficiency in 60% and 100% at concentrations of 300 and 500 mg/L methionine, respectively. Bacterial biomass sharply increased by 30, 65, and 230% with the addition of 100, 300, and 500 mg/L methionine, respectively. Bacterial community analysis showed that methionine addition supported the proliferation of a diversity of heterotrophic genera, such as Lysobacter and Micavibrio, and reduced the relative abundance of ammonium oxidizing genus Nitrosomonas. This research shows that the addition of methionine affects the performance of the partial-nitritation process. In this sense, amino acids can pose a threat for the of partial-nitritation process treating anaerobic digester supernatant at full-scale implementation.