While natural organic matter (NOM) surrogates are established in disinfection byproduct (DBP) research, their use in fractionation studies is rare. To understand how surrogates relate to drinking waters, a range of NOM surrogates were fractionated with XAD resins. Their trihalomethane (THM), haloacetic acid (HAA), haloacetaldehyde, haloacetonitrile, and haloketone formations after chlorination were recorded. While compounds with higher log K(ow) values behaved as hydrophobic acids, fractionation of the more hydrophilic compounds did not clearly correlate to the log K(ow). High HAA formation from ferulic and aspartic acids and 1,1,1-trichloropropanone (1,1,1-TCP) formation from 3-oxopropanoic acid were notable. Three amino acids, asparagine, aspartic acid, and tryptophan, formed significant levels of dichloroacetonitrile (DCAN) and trichloroacetaldehyde (TCA). Formation of DBPs did not correlate to any compound physical property; however, there were several correlations between DBP groups. The most significant were between dichloroacetic acid (DCAA) and dichloroacetonitrile (DCAN), DCAN and TCA, and dichloroacetaldehyde (DCA) and trichloroacetaldehyde, indicating the possibility of similar relationships in natural waters.

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Filamentous bulking caused by Thiothrix species is responsible for sludge washout and loss of performance in dairy wastewater treatment plants. A long-term study was conducted over 1.5 years to test three different mitigation strategies in a full-scale plant composed of two parallel sequential batch reactors (SBR1 and 2). Strategies based on polyaluminium chloride addition and volatile fatty acids reduction were ineffective to permanently solve the problem. On the contrary, modification of the reactor cycle based on the implementation of a periodic starvation proved efficient to solve the biomass wash-out and drastically reduce the sludge volume index in both reactors. Bacterial diversity analysis using 16S amplicon sequencing and quantitative PCR indicated a reduction of Thiothrix abundance from 51.9 to 1.0% in SBR1 and from 71.8 to 0.6% in SBR2. Simultaneously, the abundance of the glycogen-accumulating bacterium Candidatus Competibacter increased in both reactors. Microscopy analysis confirmed the transition between a bulking sludge towards a granular-like sludge. This study confirms the applicability of a periodic starvation to (1) solve recurring Thiothrix bulking, (2) convert loose aggregates into dense and compact granular-like structures and (3) considerably reduce energy demand for aeration.

This study aimed to explore the bacterial diversity of smoked fish and smoked‐dried fish. Forty‐eight fish samples were collected from various processing sites and markets in Benin. The bacterial diversity was analyzed using high‐throughput sequencing of the 16S rRNA gene on the Illumina MiSeq platform. In total, 16 bacterial phyla were identified across all samples, with the majority of sequences belonging to Firmicutes (43.3%) and Proteobacteria (43.6%). Families, Staphylococcaceae, Moraxellaceae, Planococcaceae, Enterobacteriaceae, Vibrionaceae, and Bartonellaceae, were well represented. A total of 384 distinct genera was identified, with the most abundant represented by the Gram‐negative, Acinetobacter, Bartonella, Enterobacter, Morganella, and Photobacterium, and the Gram‐positive, Aerococcus, Bacillus, Kurthia, Macrococcus, Staphylococcus, and Weissella. OTUs related to pathogenic bacteria, such as Salmonella spp., Staphylococcus aureus, and Listeria monocytogenes, were not detected in these popular foods sold in street markets in Benin. However, the presence of potentially harmful histamine‐producing bacteria has been revealed. Practical application In West Africa, fish is mainly preserved by hot smoking, which can be followed by an additional drying step using the heat that emanates from the kiln. Although several studies have investigated the microbiological quality of smoked and smoked‐dried fish, their overall microbial diversity has remained so far poorly explored. Therefore, this study has investigated the bacterial diversity of these popular foods. The results of this work provide useful information on bacteria potentially participating in food spoilage or compromising the safety of these popular foods and can be useful for improving their quality and safety.