Nutrient Recovery from Anaerobically Treated Blackwater and Improving Its Effluent Quality through Microalgae Biomass Production

The blackwater stream of domestic wastewater contains energy and the majority of nutrients that can contribute to a circular economy. Hygienically safe and odor-free nutrient solution produced from anaerobically treated source-separated blackwater through an integrated post-treatment unit can be used as a source of liquid fertilizer. However, the high water content in the liquid fertilizer represents a storage or transportation challenge when utilized on agricultural areas, which are often situated far from the urban areas. Integration of microalgae into treated source-separated blackwater (BW) has been shown to effectively assimilate and recover phosphorus (P) and nitrogen (N) in the form of green biomass to be used as slow release biofertilizer and hence close the nutrient loop. With this objective, a lab-scale flat panel photobioreactor was used to cultivate Chlorella sorokiniana strain NIVA CHL 176 in a chemostat mode of operation. The growth of C. sorokiniana on treated source-separated blackwater as a substrate was monitored by measuring dry biomass concentration at a dilution rate of 1.38 d−1, temperature of 37 °C and pH of 7. The results indicate that the N and P recovery rates of C. sorokiniana were 99 mg N L−1d−1 and 8 mg P L−1d−1 for 10% treated BW and reached 213 mg N L−1d−1 and 35 mg P L−1d−1, respectively when using 20% treated BW as a substrate. The corresponding biomass yield on light, N and P on the 20% treated BW substrate were 0.37 g (mol photon)−1, 9.1 g g−1 and 54.1 g g−1, respectively, and up to 99% of N and P were removed from the blackwater.

A new species of Heterotrissocladius Spärck, 1923 (Diptera: Chironomidae: Orthocladiinae) from Georgia, USA

Heterotrissocladius spiesi sp. n. is described from headwaters of two small Georgia streams, below the Fall Line in the Coastal Plain Physiologic Province, Atlantic Slope drainage. One stream is near the coast (Lower Coastal Plain) and characterized as a“blackwater” stream due to high tannin concentrations. The other stream is inland (Upper Coastal Plain), clear and not noticeably affected by tannins. The description is based on adult males, pharate male pupae and one attached larval skin. The new species is assignable to the H. marcidus species group with some exceptions. Males differ from the previous group by a reduced number of rather weak, short acrostichal setae (0-3, previously considered as typical of the subpilosus group) as well as by a very reduced wing squamal fringe compared to most members of the H. marcidus group. Males are recognizable by an elongate, thin virga, distinctive anal point and inflated/triangular gonostylus. The female is not described; the immature stages are very similar in some features to H. boltoni Sæther. At the inland stream, an adult male of the new species was found together with pharate male pupae (one with larval skin) of another, as yet undetermined species of Heterotrissocladius (marcidus group) also known from elsewhere in the state. Female adults and a pharate female pupa collected at the blackwater stream site are noted but not included in the description or type series.

A new species of Cryptonympha Lugo-Ortiz & McCafferty (Ephemeroptera, Baetidae) from Cerro Duida (Venezuela)

The genus Cryptonympha includes three species: C. copiosa Lugo-Ortiz & McCafferty, 1998; C. dasilvai Salles & Francischetti, 2004 and C. genevievae Thomas, Manchon & Glémet, 2013, known only from the nymphal stage. A description of the nymph of a fourth representative, Cryptonympha tracheata sp. n. is provided here, based on material collected in a blackwater stream on the slopes of the Cerro Duida mountain in south-western Venezuela. The nymph of the new species can be easily distinguished from the other species of the genus by very long tracheal gills II–VII, 2.5 times the length of each tergum, gill I small, nearly half length of gill IV and by posterior margin of terga with rounded spines. A complete description of the new species and a key for nymphs of all known Cryptonympha species are provided.