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Abstract Background Malaria vector control approaches that rely on mosquito releases such as the sterile insect technique (SIT) and suppression or replacement strategies relying on genetically modified mosquitoes (GMM) depend on effective mass production of Anopheles mosquitoes. Anophelines typically require relatively clean larval rearing water, and water management techniques that minimise toxic ammonia are key to achieving optimal rearing conditions in small and large rearing facilities. Zeolites are extensively used in closed-system fish aquaculture to improve water quality and reduce water consumption, thanks to their selective adsorption of ammonia and toxic heavy metals. The many advantages of zeolites include low cost, abundance in many parts of the world and environmental friendliness. However, so far, their potential benefit for mosquito rearing has not been evaluated. Methods This study evaluated the independent effects of zeolite and daily water changes (to simulate a continuous flow system) on the rearing of An. coluzzii under two feed regimes (powder and slurry feed) and larval densities (200 and 400 larvae per tray). The duration of larval development, adult emergence success and phenotypic quality (body size) were recorded to assess the impact of water treatments on mosquito numbers, phenotypic quality and identification of optimal feeding regimes and larval density for the use of zeolite. Results Overall, mosquito emergence, duration of development and adult phenotypic quality were significantly better in treatments with daily water changes. In treatments without daily water changes, zeolite significantly improved water quality at the lower larval rearing density, resulting in higher mosquito emergence and shorter development time. At the lower larval rearing density, the adult phenotypic quality did not significantly differ between zeolite treatment without water changes and those with daily changes. Conclusions These results suggest that treating rearing water with zeolite can improve mosquito production in smaller facilities. Zeolite could also offer cost-effective and environmentally friendly solutions for water recycling management systems in larger production facilities. Further studies are needed to optimise and assess the costs and benefits of such applications to Anopheles gambiae (s.l.) mosquito-rearing programmes. Graphic abstract

Background: Malaria vector control approaches that rely on mosquito releases such as the sterile insect technique (SIT) and suppression or replacement strategies relying on genetically modified mosquitoes (GMM) depend on effective mass production of Anopheles mosquitoes. Anophelines typically require relatively clean larval rearing water, and water management techniques that minimise toxic ammonia are key to achieving optimal rearing conditions in small and large rearing facilities. Zeolites are extensively used in closed-system fish aquaculture to improve water quality and reduce water consumption, thanks to their selective adsorption of ammonia and toxic heavy metals. The many advantages of zeolites include low cost, abundance in many parts of the world and environmental friendliness. However, so far, their potential benefit for mosquito rearing has not been evaluated. Methods: This study evaluated the independent effects of zeolite and daily water changes (to simulate a continuous flow system) on the rearing of An. coluzzii under two feed regimes (powder and slurry feed) and larval densities (200 and 400 larvae per tray). The duration of larval development, adult emergence success and phenotypic quality (body size) were recorded to assess the impact of water treatments on mosquito numbers, phenotypic quality and identification of optimal feeding regimes and larval density for the use of zeolite. Results: Overall, mosquito emergence, duration of development and adult phenotypic quality were significantly better in treatments with daily water changes. In treatments without daily water changes, zeolite significantly improved water quality at the lower larval rearing density, resulting in higher mosquito emergence and shorter development time. At the lower larval rearing density, the adult phenotypic quality did not significantly differ between zeolite treatment without water changes and those with daily changes. Conclusions: These results suggest that treating rearing water with zeolite can improve mosquito production in smaller facilities. Zeolite could also offer cost-effective and environmentally friendly solutions for water recycling management systems in larger production facilities. Further studies are needed to optimise and assess the costs and benefits of such applications to Anopheles gambiae (s.l.) mosquito-rearing programmes. [ABSTRACT FROM AUTHOR]

Novel bi-functional nanofibrous membrane (APAN/CS/PVA-NM) was prepared by modified bipolar jets electrospinning for chemical filtration of BPA and Cd 2+ from water. Due to opposite charge, chelating fiber (APAN) and mesopore fiber (CS/PVA) intertwined each other in a rotating collector, and formed fibrous membrane APAN/CS/PVA-NM. With high mechanical strength and permeation performance, APAN/CS/PVA-NM was preferably applied in filtration model. Cd 2+ removal by APAN/CS/PVA-NM was primary due to chelating interaction, while BPA removal was mainly by intermolecular force and hydrogen bonds. Although the operation model of chemical filtration was much different from that of fix-bed adsorption, APAN/CS/PVA-NM could be considered as a thin layer fix-bed so that filtration breakthrough curves of BPA and Cd 2+ from single solution were well predicted by Thomas model. As simultaneous filtration of binary solution, Cd 2+ show adverse effect on BPA removal because of the competition for APAN/CS/PVA-NM amino groups. However, with the increase of filtration time, more BPA adsorbed on APAN/CS/PVA-NM by intermolecular force could subsequently act as bridge molecular to increase the Cd 2+ removal. Furthermore, although preload of Cd 2+ or BPA were replaced by each other and released into solution during the sequential filtration experiment, APAN/CS/PVA-NM could still remove BPA or Cd 2+ sequentially. Multiple filtration-elution experiments indicated that more than 96% of Cd 2+ and BPA could be sequentially desorbed by HCl solution (2.0 mol/L) and ethanol, respectively. Even after 10 times cycles, APAN/CS/PVA-NM could still remain high removal rate for Cd 2+ and BPA. Thus, the present work not only provided a promising membrane for simultaneous/sequential filtration of Cd 2+ and BPA from water/wastewater but also expanded the application of electrospinning fibrous membrane in environmental protection. [ABSTRACT FROM AUTHOR]

Chitosan nanofibers (average diameter of 75 nm) were electrospun on polyester (PET) scrim to form composite nanofiber membranes with controlled pore size. The membranes were then stacked as a membrane bed for chemical filtration of Cr (VI) of 1–5 mg/L. The performance of the bed with respect to loading capacity at breakthrough, bed saturation and utilization efficiency were carefully investigated. The results showed that while these three parameters were dependent on pH, flow rate, flow distribution and packed pattern of the membrane, the latter two were less affected by feed Cr (VI) concentration and bed length. The maximum bed loading capacity for 1 mg/L Cr (VI) filtration at breakthrough was found to be 16.5 mg-chromium/g-chitosan, higher than the static adsorption capacity of 11.0 mg-chromium/g-chitosan using nanofiber mats, indicating the membranes’ better potential for dynamic adsorption. The minimum bed length required to avoid breakthrough was determined to be three layers of stacked membranes with nanofiber deposition density of 1 g/m 2 by applying bed depth service time (BDST) model. [ABSTRACT FROM AUTHOR]

An air monitoring program is in place at a wafer fab to characterize outdoor air quality and its potential impact on manufacturing processes. Airborne molecular contamination (AMC), and specifically acid contamination, was of particular concern as the facility incorporated 90-nanometer (nm) manufacturing technology. Impinger ionic analysis, passive and real-time reactivity monitoring, and litmus paper hue readings were among the techniques used to assess air quality. Historical data for each monitoring technique was evaluated and compared to determine the applicability of each monitoring technique for these purposes. Data from this monitoring program also offered an opportunity to evaluate the performance of chemical filters installed in makeup air handling units for their ability to remove AMC. This study presents the results of air monitoring, detailing outdoor air quality and how that air quality compares to established specifications; comparison of different monitoring techniques used in the study; performance of installed chemical filter systems; recommendations for improving acid contamination control and evaluation of selected options; and recommendations for overall AMC monitoring and control programs. [ABSTRACT FROM AUTHOR]

The characterization of uranium and other radionuclides is important to programs in nuclear forensics. Commonly, isotope-ratio mass spectrometry (IRMS) is employed as a laboratory-based system for quantification of isotope ratios (IR) to shed light on the degree of processing. Transporting nuclear material from the field to the laboratory is problematic while laborious sample processing and long analysis times make IRMS less amenable to real-time measurement. Because size, weight, and power (SWaP) requirements make conventional IRMS difficult to implement for on-site applications, it is attractive to develop IR analysis on an ion trap mass spectrometer which is amenable to field portability. A hindrance to in situ analysis includesmatrix interferences which are best handled by some separation method. Notably, ion mobility instruments have been commonly demonstrated in field use, and, in particular, differential mobility spectrometry (DMS) is a promising companion separation technique to ion traps. DMS enables tunable filtration prior to ion trap MS analysis, removing chemical interferences to address the heterogeneous nature of radionuclides and fission products. DMS may be particularly useful for removing molecular isobaric interferences and, as such, pairing DMS with ion trap MS has potential for fieldable IR analysis. Herein, DMS was coupled to a linear ion trap (LIT) for pre-filtration of uranyl ion (UO 2 +) from chemical background produced from nano electrospray ionization. Subsequently, isotopic analysis was conducted on the uranyl ion. The 235U/238U ratio measured with the DMS-MS system showed improved signal-to-background, compared to MS alone. Pairing DMS to LITMS improves the accuracy of the MS, while precision of the MS appears to be limited by the precision of the LIT. After DMS filtration, the isotope ratio measurement of 235U/238U decreased from 0.00913 to 0.00713, with the standardized uncertainty improving from 26.58% to 7.21%. Such results indicate that DMS may generally impart greater confidence of nuclear IRMS measurements. [Display omitted] • Differential mobility spectrometry (DMS) permits filtration of isobaric interferences removing a source of systematic uncertainty. • Solution standards of uranium in inorganic mixtures are nanosprayed into DMS coupled to LITMS. • Accuracy is improved with relative errors ∼5% for 235U/238U to better support classification of nuclear materials. • Determination of uranium isotope ratios may potentially be enabled in fieldable ion trap systems by coupling with DMS. [ABSTRACT FROM AUTHOR]

Rotating cylindrical stamp-based nanoimprint technique has many advantages, including the continuous fabrication of intriguing micro/nanostructures and rapid pattern transfer on a large scale. Despite these advantages, the previous nanoimprint lithography has rarely been used for producing sophisticated nanoscale patterns on a non-planar substrate that has many extended applications. Here, the simple integration of nanoimprinting process with a help of a transparent stamp wrapped on the cylindrical roll and UV optical source in the core to enable high-throughput pattern transfer, particularly on a fabric substrate is demonstrated. Moreover, as a functional resin material, this innovative strategy involves a synergistic approach on the synthesis of molecularly imprinted polymer, which are spatially organized free-standing perforated nanostructures such as nano/microscale lines, posts, and holes patterns on various woven or nonwoven blank substrates. The proposed materials can serve as a self-encoded filtration medium for selective separation of formaldehyde molecules. It is envisioned that the combinatorial fabrication process and attractive material paves the way for designing next-generation separation systems in use to capture industrial or household toxic substances., (© 2021 Wiley-VCH GmbH.)

Water quality plays an important role in ensuring the healthy growth of aquatic living. Fish in ponds release nitrogen, phosphorus, ammonia, nitrates and organic waste. The presence of these chemicals in water leads to an increment in the pH level of the pond water, which could affect the growth of the fish. Therefore, it is vital to have an effective filter system for pond water to remove the unwanted waste. At current literature, the filtering effectiveness of activated carbon and zeolite in fresh water pond systems are remained inexplicit. In this work, a lab-scale filtering system was set up to study the ammonia removal efficiency of activated carbon and zeolite. The efficiency of these two types of filtering media was first studied separately and then combined as a hybrid filter with a weight ratio of 1:1. The effectiveness of the single filter media and hybrid media filter were evaluated based on the measurement of the concentration of ammonia, nitrite and nitrate, and the pH level. It was found that the hybrid filter – a combination of activated carbon and zeolite – tended to have higher efficiency in maintaining good water quality compared to the single media system; the ammonia level was reduced from 4 mg/L to 1 mg/L in 2.5 days. The greater the amount of the hybrid filter media presents in the system, the better the conversion rate of ammonia to nitrate. A combination of activated carbon and zeolite (150 g each) was found to be able to maintain suitable water quality (1 mg/L ammonia, 0 mg/L nitrite, <50 mg/L nitrate, 6.8–8.0 pH) for fish. [ABSTRACT FROM AUTHOR]