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Presents a correction to the article "Inactivation of Ascaris suum Eggs in Digested and Dewatered Biosolids With Lime and Fly Ash at Bench Scale and Full Scale," by J. Brewster, J. Oleszkiewicz, G. Bujoczek, R. S. Reimers, M. Abu-Orf, D. Bowman and E. Fogarty.

Conditioning of wastewater sludges with polyelectrolytes prior to dewatering is necessary to increase the sludges' dewaterability. Duringthis conditioning process adequate mixing of the conditioner and thesludge must be attained. This research reports on results from full-scale experiments conducted to examine the effect of mixing parameters upon the conditioned sludge and liquid stream rheological characteristics. [ABSTRACT FROM AUTHOR]

Amplitude compression is an indispensable feature of contemporary audio production and especially relevant in modern hearing aids. The cortical fate of amplitude-compressed speech signals is not well-studied, however, and may yield undesired side effects: We hypothesize that compressing the amplitude envelope of continuous speech reduces neural tracking. Yet, leveraging such a 'compression side effect' on unwanted, distracting sounds could potentially support attentive listening if effectively reducing their neural tracking. In this study, we examined 24 young normal-hearing (NH) individuals, 19 older hearing-impaired (HI) individuals, and 12 older normal-hearing individuals. Participants were instructed to focus on one of two competing talkers while ignoring the other. Envelope compression (1:8 ratio, loudness-matched) was applied to one or both streams containing short speech repeats. Electroencephalography (EEG) allowed us to quantify the cortical response function and degree of speech tracking. With compression applied to the attended target stream, HI participants showed reduced behavioural accuracy, and compressed speech yielded generally lowered metrics of neural tracking. Importantly, we found that compressing the ignored stream resulted in a stronger neural representation of the uncompressed target speech. Our results imply that intelligent compression algorithms, with variable compression ratios applied to separated sources, could help individuals with hearing loss suppress distraction in complex multi-talker environments. Significant statement Amplitude compression, integral in contemporary audio production and hearing aids, poses an underexplored cortical challenge. Compressing the amplitude envelope of continuous speech is hypothesized to diminish neural tracking. Yet, capitalizing on this 'compression side effect' for distracting sounds might enhance attentive listening. Studying normal-hearing (NH), older hearing-impaired (HI), and older normal hearing individuals in dual-talker scenarios, we applied envelope compression to speech streams. Both NH and HI participants showed diminished neural tracking with compression on the speech streams. Despite weaker tracking of a compressed distractor, HI individuals exhibited stronger neural representation of the concurrent target. This suggests that adaptive compression algorithms, employing variable ratios for distinct sources, could aid individuals with hearing loss in suppressing distractions in complex multi-talker environments., (Copyright © 2025 the authors.)

Concerns surrounding potential health and environmental impacts of per- and polyfluoroalkyl substances (PFAS) are growing at tremendous rates because adverse health impacts are expected with trace-level exposures. Extreme measures are required to mitigate potential PFAS contamination and minimize exposures. Extensive PFAS use results in the release of diverse PFAS species from domestic, industrial, and municipal effluents to wastewater, which partition to biosolids throughout secondary treatment. Biosolids generated during municipal wastewater treatment are a major environmental source of PFAS due to prevailing disposal practices as fertilizers. Pyrolysis is emerging as a viable, scalable technology for PFAS removal from biosolids while retaining nutrients and generating renewable, raw materials for energy generation. Despite early successes of pyrolysis in PFAS removal, significant unknowns remain about PFAS and transformation product fates in pyrolysis products and emissions. Applicable PFAS sampling methods, analytical workflows, and removal assessments are currently limited to a subset of high-interest analytes and matrices. Further, analysis of exhaust gases, particulate matter, fly ashes, and other pyrolysis end-products remain largely unreported or limited due to cost and sampling limitations. This paper identifies critical knowledge gaps on the pyrolysis of biosolids that must be addressed to assess the effectiveness of PFAS removal during pyrolysis treatment., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

Selective attention modulates the neural tracking of speech in auditory cortical regions. It is unclear whether this attentional modulation is dominated by enhanced target tracking, or suppression of distraction. To settle this long-standing debate, we employed an augmented electroencephalography (EEG) speech-tracking paradigm with target, distractor, and neutral streams. Concurrent target speech and distractor (i.e., sometimes relevant) speech were juxtaposed with a third, never task-relevant speech stream serving as neutral baseline. Listeners had to detect short target repeats and committed more false alarms originating from the distractor than from the neutral stream. Speech tracking revealed target enhancement but no distractor suppression below the neutral baseline. Speech tracking of the target (not distractor or neutral speech) explained single-trial accuracy in repeat detection. In sum, the enhanced neural representation of target speech is specific to processes of attentional gain for behaviorally relevant target speech rather than neural suppression of distraction., Competing Interests: The authors declare no competing interests., (© 2023 The Author(s).)

The objective of this study was to investigate the use of ultrasonic energy in an internal recycle and pretreatment mode of operation relative to a conventional mode of mesophilic anaerobic digestion. The primary focus was to determine if using ultrasonics in a pretreatment mode and in an internal recycle line produced changes in performance relative to each other and the control. Using a relatively low-energy sonication system, the data showed that the addition of ultrasonic energy, in either a recycle line or as a pretreatment technology, improved anaerobic digestion efficiency for waste-activated sludge. There was a 13 to 21% increase in biogas yield and an increase in total and volatile solids destruction of 3 to 10.3 additional percentage points, depending on the ultrasonic dose and location. Dewatering of the biosolids following ultrasonic treatment was poorer, as measured by an increase in the optimum polymer conditioning dose. The addition of ultrasonics to the digestion systems generated a more stable biosolids product, with a 2 to 58% reduction in organo-sulfur gas production from dewatered biosolids cakes.

A combination of bench- and full-scale studies were conducted to determine the effectiveness of high-intensity mechanical shear in an internal recycle loop to enhance mesophilic anaerobic digestion and the implications of this process for routine operations of a digestion system. During short-term batch digestion (56 hours), a 46% increase in biogas production was observed. However, it was found that the degree of digestion enhancement was sludge-specific, with increases in volatile solids destruction ranging from 16.6 to 110%. A full-scale demonstration showed increased total and volatile solids destruction of 22 and 21% for the primary digester and 17.2 and 11% for the secondary digester, respectively. The data also suggest that increased protein degradation is one of the major mechanisms associated with the observed increases in volatile solids destruction. The full-scale demonstration also determined that shear enhanced digestion can be operated without process upset, based on volatile fatty acid profile and headspace biogas composition (methane and carbon dioxide). Dewatering properties, as measured by polymer demand, deteriorated in the primary digester, but there was improvement in the secondary digester. High-intensity shear does not appear to enhance pathogen reduction based on total and fecal coliform bacterial enumeration.

The cationic organic polymers used to enhance thickening and dewatering processes are potential sources of strong odors. These polymers vary in chemical structure, and some may be more susceptible to biotic or abiotic degradation than others. The product organic amines will be volatilized most noticeably at high pH, as in lime addition. These possibilities were examined using several structural types of polymers combined with anaerobically digested sludge. Two commonly used polymers gave significant production of trimethylamine (TMA), which was released upon lime addition. Their structures were correlated with reactions that yield TMA. An initial ester hydrolysis step appears to be biologically mediated, but subsequent steps can occur due to alkaline conditions. An alternative cationic polymer structure did not generate TMA but required a much higher dose to effect sufficient conditioning of the sludge. The acrylamide-based polymers were shown to be the predominant source of TMA in limed sludges.

Dewatering problems associated with the sludge from autothermal thermophilic aerobic digestion (ATAD) of sludge, result in large chemical conditioning costs for effective dewatering. A variety of chemical conditioners were used to improve dewatering, but none of them were able to dewater the sludge as desired at acceptable conditioning doses. It was found that during the digestion process, chemical precipitation of divalent cations occurred. Some of the ATAD sludge colloids were found to have a positive zeta potential and these were thought to be the precipitated divalent cations. Sequential polymer dosing using either iron or cationic polymer, followed by anionic polymer, was found to improve dewatering. The use of anionic polymer is essential and allows the use of smaller amounts of iron or cationic polymer for effective dewatering. The use of the less expensive anionic polymer along with cationic polymers has the potential to make the use of the ATAD process more economical.

Complaints from the public due to odor emissions are one of the biggest problems associated with any biosolids land application program. Chemical additives to reduce or mask odors are one option for producers; however, many chemicals are too expensive or are too unstable to use safely. This project provides a preliminary evaluation of nitrate or nitrate + anthraquinone as additives in controlling odors from limed biosolids. Over a twenty-four day period, odors were measured in the headspace over several treatment levels using two different chemical analysis tools along with olfactometric evaluation of odor intensity and hedonic tone. On six days during the sample period, hydrogen sulfide was measured using a Jerome 631X, a sensor that also responds to other reduce sulfur gases. Other specific sulfides, amines, and mercaptans were also determined using solid phase microextraction with gas chromatography-mass spectrometry. A simple sniff test approach was used with six panelists on five days during the project. The chemical analysis results revealed that the addition of nitrate and especially nitrate + anthraquinone was effective in reducing concentrations of hydrogen sulfide and methylmercaptan when compared to untreated limed biosolids. However, the olfactometric results did not reveal any significant differences between treatments. The panelists also found that all treatments exhibited a fishy or ammonical character, indicative of amines, or ammonia. More advance olfactometric analysis utilizing dilution techniques might have been able to distinguish between treatments, but it is likely that amines were the dominant odorant released from all treatments. This preliminary project suggests that chemical addition of nitrate or nitrate + anthraquinone would be most effective in controlling odors from unlimed biosolids such as anaerobically digested materials.

The feasibility of full-scale anoxic disinfection of dewatered and digested sludge from Winnipeg, Manitoba with low lime doses and lagoon fly ash was investigated to determine if a class A product could be produced. Lime doses of 50 g, 100 g, and 200 g per kg of biosolids (dry) were used along with fly ash doses of 500 g, 1,000 g, and 1,500 g per kg of biosolids (dry). The mixed product was buried in eight-10 cubic metre trenches at the West End Water Pollution Control Center in Winnipeg. The trenches were backfilled with dirt and trapped to simulate anoxic conditions. Sampling cages were packed with the mixed product and pathogens non-indigenous to Winnipeg's biosolids. The cages were buried amongst the mixed biosolids in the trench. The non-indigenous pathogens spiked in the laboratory were the helminth Ascaris suum and the enteric virus reovirus. Samples were removed at days 12, 40, 69, 291, and 356 and were tested for the presence of fecal Coliform, Clostridium perfringens spores, Ascaris suum eggs, and reovirus. The pH, total solids, and free ammonia content of the mixed product were also determined for each sample. Odor was quantified for samples at both 291 and 356 days. Fecal Coliform bacteria and reovirus were completely inactivated for doses as low as 100 g lime per kg biosolids (dry) and 50 g lime + 500 g fly ash per kg biosolids (dry). Spores of the bacteria C. perfringens experienced a 4-log reduction when treated with 100 g lime per kg biosolids and a 5-log reduction when treated with doses as low as 50 g lime + 500 g fly ash per kg biosolids (dry) after 69 days. Ascaris eggs were completely inactivated in 5 gram packets for all treatments involving 100 g lime per kg biosolids (dry) after 69 days. Class A pathogen requirements were met for all treatments involving a lime dose of at least 100 g per kg biosolids. The odor potential from the produced biosolids is also assessed.

This paper reports on two modifications to the typical practice of polymer conditioning intended to enhance the dewaterability of autothermal thermophilic aerobic digested (ATAD) biosolids. One modification was a chemical pretreatment, using ferric chloride prior to polymer conditioning, and the other was a physical pretreatment using an electrical arc technology before polymer addition. These modifications were evaluated separately and in combination, in laboratory conditioning experiments using ATAD biosolids. Results showed that neither ferric chloride nor the arc treatment is sufficient to produce dewaterable biosolids without the use of polymer. However, use of a ferric chloride dose as low as 100 g per kg of dry solids reduced the polymer requirement by about 50%. The arc treatment provided further enhancement of dewaterability, but the observed benefits might not justify its use without further optimization. For this purpose, additional methods were utilized to assist in understanding the pretreatment mechanisms.

Gene flow and introgression from cultivated plants may have important consequences for the conservation of wild plant populations. Cultivated beets (sugar beet, red beet and Swiss chard: Beta vulgaris ssp. vulgaris) are of particular concern because they are cross-compatible with the wild taxon, sea beet (B.vs. ssp. maritima). Cultivated beet seed production areas are sometimes adjacent to sea beet populations; the numbers of flowering individuals in the former typically outnumber those in the populations of the latter. In such situations, gene flow from cultivated beets has the potential to alter the genetic composition of the nearby wild populations. In this study we measured isozyme allele frequencies of 11 polymorphic loci in 26 accessions of cultivated beet, in 20 sea beet accessions growing near a cultivated beet seed production region in northeastern Italy, and 19 wild beet accessions growing far from seed production areas. We found one allele that is specific to sugar beet, relative to other cultivated types, and a second that has a much higher frequency in Swiss chard and red beet than in sugar beet. Both alleles are typically rare in sea beet populations that are distant from seed production areas, but both are common in those that are near the Italian cultivated beet seed production region, supporting the contention that gene flow from the crop to the wild species can be substantial when both grow in proximity. Interestingly, the introgressed populations have higher genetic diversity than those that are isolated from the crop. The crop-to-wild gene flow rates are unknown, as are the fitness consequences of such alleles in the wild. Thus, we are unable to assess the long-term impact of such introgression. However, it is clear that gene flow from a crop to a wild taxon does not necessarily result in a decrease in the genetic diversity of the native plant.