Explore the vast range of titles available.

To deal with issues of process sustainability, cost, and efficiency, we developed materials reengineered from fibers to serve as super-bridging agents, adsorbents, and ballast media. These sustainable fiber-based materials considerably increased the floc size (~6,630 µm) compared to conventional physicochemical treatment using a coagulant and a flocculant (~520 µm). The materials also reduced coagulant usage (up to 40%) and flocculant usage (up to 60%). These materials could be used in synergy with coagulants and flocculants to improve settling in existing water treatment processes and allow facilities to reduce their capital and operating costs as well as their environmental footprint. Moreover, the super-sized flocs produced using fiber-based materials (up to ~13 times larger compared to conventional treatment) enabled easy floc removal by screening, eliminating the need for a settling tank, a large and costly process unit. The materials can be effective solutions at removing classical (e.g., natural organic matter (NOM) and phosphorus) and emerging contaminants (e.g., microplastics and nanoplastics). Due to their large size, Si- and Fe-grafted fiber-based materials can be easily recovered from sludge and reused multiple times.

A compact three-in-one water treatment process, combining a flocculant, a fibrous super-bridging agent, and a screen-based floc retention system, simultaneously improves water treatment and sludge dewatering. The presence of fibrous materials allows for the formation of very large flocs, efficient floc separation via screening (without settling), and sludge dewatering through a compact press-filter system. The implementation of this three-in-one process is possible due to the formation of very large fiber-based flocs. The sludge containing fibers was subsequently dewatered using a screen-based press filter without further chemical addition. The use of fibers also significantly improved the removal of total organic carbon, nanoplastics, and microplastics. This three-in-one process could be used for decentralized water treatment in drinking water and wastewater applications in small cities, marginalized communities, and developing countries. The compact process, which also performs sludge dewatering, would reduce the risks associated with mismanaged sludge to the environment and human health.

Growing genetic evidence is converging in favor of common pathogenic mechanisms for autism spectrum disorders (ASD), intellectual disability (ID or mental retardation) and schizophrenia (SCZ), three neurodevelopmental disorders affecting cognition and behavior. Copy number variations and deleterious mutations in synaptic organizing proteins including NRXN1 have been associated with these neurodevelopmental disorders, but no such associations have been reported for NRXN2 or NRXN3 . From resequencing the three neurexin genes in individuals affected by ASD ( n  = 142), SCZ ( n  = 143) or non-syndromic ID ( n  = 94), we identified a truncating mutation in NRXN2 in a patient with ASD inherited from a father with severe language delay and family history of SCZ. We also identified a de novo truncating mutation in NRXN1 in a patient with SCZ, and other potential pathogenic ASD mutations. These truncating mutations result in proteins that fail to promote synaptic differentiation in neuron coculture and fail to bind either of the established postsynaptic binding partners LRRTM2 or NLGN2 in cell binding assays. Our findings link NRXN2 disruption to the pathogenesis of ASD for the first time and further strengthen the involvement of NRXN1 in SCZ, supporting the notion of a common genetic mechanism in these disorders.

Polyacrylamide polymers (PAM) are one of the most common water treatment chemicals used in clarification processes. Concerns have been raised with regards to the aquatic and human toxicity of acrylamide monomer. Greener polymers, produced using potato starch, were investigated at lab-scale as a potential non-toxic alternative to the use of PAM within a ballasted flocculation process (Actiflo®). Even under extreme temperature (1 °C), starch and PAM showed comparable turbidity removal performances, although higher starch dosages (four to five times) were needed to achieve such results. Compared to PAM, activated starch polymers also benefited from the use of lower mixing energy and smaller microsand. A slight biodegradable dissolved organic carbon (BDOC) release (≈0.15 mg C/L) was also measured while using starch polymer, but this did not impact trihalomethane and haloacetic acid formation. These results indicate that activated starch polymers represent a promising alternative to the use of PAM polymers in a ballasted flocculation process.

With growing concerns over plastic accumulation in the environment, it is imperative to quantify nanoplastic and microplastic release to water bodies via water treatment plant effluent streams. Current methodological limitations present a major challenge for continuous monitoring of nanosized pollutants in effluent streams. In this work, a novel correlation was established between removal of nanoplastics and total suspended solids (TSS) during aggregation-based wastewater treatment. The established correlation successfully predicted nanoplastic removal for a wide range of relevant nanoplastic properties, including polymer type, size, surface functionalization and ageing history, under 41 different physico-chemical and activated sludge treatment conditions (R2 = 0.92; n = 117). The results of our correlation reveal a predicted nanoplastic removal between 39% and 69% for typical water treatment effluent streams governed by current TSS regulations in North America. The study also reveals the potential of using TSS as a simple metric to estimate microfibre, microsphere and microfragment removal.Although it is widely acknowledged that nanoplastic and microplastic contaminants are omnipresent in the environment, the role of water treatment plants in the fate of these contaminants is unclear. Correlating nanoplastic removal with total suspended solids removal in water is shown to be a reliable method for predicting how much nanoplastic can be removed by wastewater treatment plants.

Due to technological, economic and environmental constraints, contemporary treatment plants cannot treat all wastewater. In particular, the very high amount of agricultural and urban runoff to be treated is increasingly concerning, especially with more erratic — and unpredictable — rainfall events. Passive ecosystem services can be combined with engineered processes to create hybrid, locally adapted, inexpensive and sustainable technologies to more feasibly treat runoff and wastewater globally.

Schizophrenia likely results from poorly understood genetic and environmental factors. We studied the gene encoding the synaptic protein SHANK3 in 285 controls and 185 schizophrenia patients with unaffected parents. Two de novo mutations (R1117X and R536W) were identified in two families, one being found in three affected brothers, suggesting germline mosaicism. Zebrafish and rat hippocampal neuron assays revealed behavior and differentiation defects resulting from the R1117X mutant. As mutations in SHANK3 were previously reported in autism, the occurrence of SHANK3 mutations in subjects with a schizophrenia phenotype suggests a molecular genetic link between these two neurodevelopmental disorders.

The oceans globally constitute an important sink for carbon dioxide (CO₂) due to phytoplankton photosynthesis. However, the marine environment imposes serious restraints to carbon fixation. First, the equilibrium between CO₂ and bicarbonate (HCO₃⁻) is pH dependent, and, in normal, slightly alkaline seawater, [CO₂] is typically low (approximately 10 μM). Second, the rate of CO₂ diffusion in seawater is slow, so, for any cells unable to take up bicarbonate efficiently, photosynthesis could become carbon limited due to depletion of CO₂ from their immediate vicinity. This may be especially problematic for those dinoflagellates using a form II Rubisco because this form is less oxygen tolerant than the usually found form I enzyme. We have identified a carbonic anhydrase (CA) from the free-living marine dinoflagellate Lingulodinium polyedrum that appears to play a role in carbon acquisition. This CA shares 60% sequence identity with δ-class CAs, isoforms so far found only in marine algae. Immunoelectron microscopy indicates that this enzyme is associated exclusively with the plasma membrane. Furthermore, this enzyme appears to be exposed to the external medium as determined by whole-cell CA assays and vectorial labeling of cell surface proteins with ¹²⁵I. The fixation of ¹⁴CO₂ is strongly pH dependent, suggesting preferential uptake of CO₂ rather than HCO₃⁻, and photosynthetic rates decrease in the presence of 1 mM acetazolamide, a non-membrane-permeable CA inhibitor. This constitutes the first CA identified in the dinoflagellates, and, taken together, our results suggest that this enzyme may help to increase CO₂ availability at the cell surface.

La floculation lestée est largement utilisée en Amérique du Nord et en Europe lors du traitement des eaux potables, usées et industrielles. Sa popularité s’explique notamment par son efficacité d’enlèvement des flocs, sa compacité, sa facilité de mise en œuvre et sa robustesse vis-à-vis des variations de qualité de l’affluent. Cette technologie de traitement requiert l’utilisation d’un média lestant, ce dernier permettant d’augmenter la densité et la taille des flocs. Plusieurs types de médias peuvent être utilisés. Des technologies employant du sable de silice, de la magnétite, du charbon actif ou des boues de décantation comme médias lestants sont commercialisées depuis plus de 30 ans. Un floculant synthétique de poids moléculaire élevé (viz, le polyacrylamide) est indispensable à la floculation lestée. En plus de permettre la liaison entre les microflocs coagulés et le média lestant, il améliore la cinétique d’agrégation et augmente la résistance des flocs au cisaillement.