ABSTRACT
Batch equilibrium phosphorus concentration (EPC0) methods were applied to determine phosphorus capacity of sediments from three agriculturally influenced tributaries in southern Ontario - Belle River, Big Creek, and Nissouri Creek. Aliquots of sediments were amended with soluble reactive phosphorus and incubated at four temperatures (5, 15, 25, and 35°C). Batches of sediments from each location and temperature were also subjected to a treatment; gamma (γ)-irradiated at 28 kGy over 24-h (sterilized) and compared to non-sterilized biotic samples. Treatment showed a significant effect on EPC0 in Belle River and Nissouri Creek but non-significant effect in Big Creek. Temperature showed a significant effect in Belle River, Nissouri Creek, and the biotic subset of Big Creek. While direction of shift was not consistent in all cases, the biotic subsets of all three locations showed a significant effect of temperature.
Subject(s)
Geologic Sediments/chemistry , Geologic Sediments/microbiology , Microbiota , Phosphorus/analysis , Rivers/chemistry , Water Pollutants, Chemical/analysis , Adsorption , Agriculture , Models, Theoretical , OntarioABSTRACT
A comparative bench-scale and field site analysis of BioCord was conducted to investigate seasonal microbial community dynamics and its impact on nitrogen removal in wastewater. This was assessed using metabolite (NO3 -) stable isotope analysis, high-throughput sequencing of the 16S rRNA gene, and RT-qPCR of key genes in biological treatment representing nitrification, anammox, and denitrification. Bench-scale experiments showed an increase in nitrifiers with increasing ammonia loading resulting in an ammonia removal efficiency up to 98 ± 0.14%. Stable isotope analysis showed that 15É and δ18ONO3 could be used in monitoring the efficiency of the enhanced biological nitrification. In the lagoon field trials, an increase in total nitrogen promoted three principle nitrifying genera (Nitrosomonas, Nitrospira, Candidatus Nitrotoga) and enhanced the expression of denitrification genes (nirK, norB, and nosZ). Further, anaerobic ammonia oxidizers were active within BioCord biofilm. Even at lower temperatures (2-6°C) the nitrifying bacteria remained active on the BioCord.
