Net Removal Research Articles

Pharmacokinetics of Vancomycin in Pediatric Patients Receiving Intermittent Hemodialysis or Hemodiafiltration

IntroductionVancomycin is a common antibiotic used to treat hemodialysis (HD) or hemodiafiltration (HDF)-related infections in pediatric patients, but optimal dosing remains unknown. This is the first observational study to characterize the pharmacokinetics and evaluate dosing of vancomycin in this population.MethodsEligible patients received IV vancomycin 10 mg/kg per dose postdialysis followed by a series of serum vancomycin concentrations collected before, immediately after, 1 hour after, and 4 hours after dialysis. The pharmacokinetic parameters were estimated using 1- and 2-compartment models and a nonlinear least-squares algorithm.ResultsAmong 42 vancomycin courses in 16 patients, 1 compartment model had the best fit for observed data. The net drug removal was 43 ± 13% (39% for HD and 50% for HDF) from an average 3-hour HD/HDF session. The mean elimination constant was 0.28 h−1 (standard deviation [SD], 0.11 h−1) during the intradialytic period compared with 0.0049 h−1 (SD, 0.004 h−1) when off dialysis. The mean volume of distribution was 0.65 (SD, 0.19) L/kg. Duration of dialysis session and mode of dialysis (HD vs. HDF) were significant predictors of vancomycin pharmacokinetic parameters. Half-life was shorter for HDF compared with HD (2.1 vs. 3.5 hours).ConclusionsBased on the simulations, an initial vancomycin dose of 10 mg/kg per dose and redosing postdialysis was optimal to achieve a vancomycin concentration range of 5 to 12 mg/L at 4 hours postdialysis and 24-hour area under the curve over minimum inhibitory concentration of ≥400 hours. Therapeutic drug monitoring is necessary to account for residual variability in vancomycin elimination in pediatric patients receiving HD/HDF.

Fabrication of rGO-CuO and/or Ag2O nanoparticles incorporated polyvinyl acetate based mixed matrix membranes for the removal of Cr6+ from anti-corrosive paint industrial wastewater

Herein we report the fabrication of ternary system mixed matrix membranes based on polyvinyl acetate (PVAc) incorporated reduced graphene oxide (rGO) and CuO or Ag2O nanoparticles as filler in different weight ratios via non-solvent induced phase inversion separation method. The fabricated membranes were characterized for chemical composition porosity, pore distribution, surface roughness, thickness, water contact angle and mechanical strength. Scanning electron microscopy and atomic force microscopy analyses revealed that pure PVAc exhibited smooth and uniform surface while PVAc/rGO/Ag2O and PVAc/rGO/ACuO membranes possessed rough and uneven topography and higher surface porosity. PVAc/rGO/CuO and PVAc/rGo/Ag2O membranes exhibited total permeate flux of 1.60 × 10–2 g/m2 s and 1.28 × 10–2 g/m2 s corresponding to net removal of 99.9% and 98.0% respectively from model wastewater of Cr6+ under the optimized experimental conditions. Interestingly, under these optimized conditions, PVAc/rGO/CuO membrane achieved Cr6+ removal of 99.9% from anti-corrosive paint industrial wastewater (as real sample) with a flux of 1.90 × 10-2 g/m2 s, which was much higher than many state of the art membranes. The uptake of Cr6+ from real solution was confirmed by EDX and AFM analysis of the post-separation membrane. The newly designed PVAc/rGO/CuO membrane, attributed to cost-effectiveness, environmental greenness, ease of syntheisis and high efficiency, can be envisioned of potential applications for the remediation of Cr6+ and other similar pollutants from real industrial wastewater.

Emergency deployment of direct air capture as a response to the climate crisis

Though highly motivated to slow the climate crisis, governments may struggle to impose costly polices on entrenched interest groups, resulting in a greater need for negative emissions. Here, we model wartime-like crash deployment of direct air capture (DAC) as a policy response to the climate crisis, calculating funding, net CO2 removal, and climate impacts. An emergency DAC program, with investment of 1.2–1.9% of global GDP annually, removes 2.2–2.3 GtCO2 yr–1 in 2050, 13–20 GtCO2 yr–1 in 2075, and 570–840 GtCO2 cumulatively over 2025–2100. Compared to a future in which policy efforts to control emissions follow current trends (SSP2-4.5), DAC substantially hastens the onset of net-zero CO2 emissions (to 2085–2095) and peak warming (to 2090–2095); yet warming still reaches 2.4–2.5 °C in 2100. Such massive CO2 removals hinge on near-term investment to boost the future capacity for upscaling. DAC is most cost-effective when using electricity sources already available today: hydropower and natural gas with renewables; fully renewable systems are more expensive because their low load factors do not allow efficient amortization of capital-intensive DAC plants.

Electrolysis-enhanced ecological floating bed and its factors influencing nitrogen and phosphorus removal in simulated hyper-eutrophic water.

To enhance ammonia nitrogen (NH3-N) and phosphate (PO43--P) removal in hyper-eutrophic water, electrolysis-enhanced ecological floating bed (EEEFB) was designed with a Mg-Al alloy anode, a Ir-Ta-Ti metal oxide-coated titanium anode, and an Fe anode with the same graphite cathode. The results showed that the Mg-Al alloy anode with graphite cathode had a better ability to enhance NH3-N and PO43--P removal. When the current density was 0.37 mA·cm-2, the electrolysis time was 24 h/d, and the net removal rates of NH3-N and PO43--P were 62% and 99.4%, respectively. In winter, the purification efficiencies of NH3-N and PO43--P were as high as 7388.4 mg·m-2 and 4297.5 mg·m-2, respectively, by EEEFBs which were significantly higher than the traditional ecological floating bed (p < 0.05). Scanning electron microscopy (SEM) and X-ray spectrometry confirmed that the PO43--P was deposited in the sediment of EEEFBs with Mg-Al alloy anode and Fe anode.

Negative emissions using Mg sourced from desalination brine or natural evaporite deposits

We establish a profitable negative emissions technology that converts desalination brine or salt deposits into saleable products while concurrently mineralizing atmospheric CO2 as Mg-carbonates. The process produces water, gypsum, salt, potash, aggregate, and hydrochloric acid with the ratios of products dependent on the brine or evaporite deposit composition. In addition to the negative emissions realized through direct removal of CO2 from the atmosphere, the co-products drive out existing production methods resulting in CO2 emissions reduction. Notably, the process uses no chemicals or fossil fuels and can be powered completely by electricity. This not only increases the net CO2 removal it also leverages the decreasing cost of renewables and batteries to increase operating profit. We outline how extant equipment and technologies can be used to implement this process. The net energy usage and CO2 removal of the process are calculated, accounting for differences with current production methods for the co-products. At large enough implementation, some products will saturate their respective markets, converting the excess product into a waste stream. As such, performance indices for the process (e.g., GJ/t-CO2, USD/t-CO2) depend on the extent of implementation. We limit our investigation to prior to such market saturation effects. Assuming the global average CO2 intensity of electricity generation, the process provides 4.1 t-CO2 of emissions reduction for every tonne of negative CO¬ emissions. Per tonne of total CO2 reduction (mitigated+removed), the process operates at an energy consumption of 2.1 GJ/t-CO2, falling to 1.1 GJ/t-CO2 if the system is powered by renewable energy. Via Monte Carlo analysis using global price distributions, we find that even without including a price on CO2 the process operates, on average, at a profit of 196 USD/t-CO2 (total reduction). Applying the process to evaporite deposits of Bischofite or Carnallite provides a profit of 47 USD/t-CO2 and 103 USD/t-CO2 (total reduction), respectively.

Nutrient removal in a slow-flowing constructed wetland treating aquaculture effluent

Danish model trout farms (MTFs) use stream-like constructed wetlands for effluent polishing, and the industry is keen to improve wetland removal efficiency. To facilitate this, we examined longitudinal and seasonal nutrient removals in an MTF wetland with a hydraulic retention time (HRT) of 1.7 d, a free water surface (FWS) area of 7510 m2, and a volume of 6008 m3. Biweekly, 24-h composite water samples were obtained for 1 yr at 6 sampling stations along the wetland. Assuming plug flow conditions, reductions in particulate and dissolved nutrient concentrations were modelled as first-order removal processes, and removal rate constants (k1,A, m d-1) were plotted to reveal seasonal fluctuations. Particulate phosphorus and organic matterk1,Afluctuated more or less randomly through the year, reflecting that particulate nutrient removal predominantly takes place by sedimentation. In contrast, dissolved nitrogen, phosphorus, and organic matterk1,Afluctuated seasonally, demonstrating that dissolved nutrient removal relies on biologically mediated processes. Temperature oscillations probably governed the observed seasonal fluctuations in nitrate-Nk1,Aand could be approximated with an Arrhenius temperature coefficient of 1.07. Furthermore, denitrification appeared to be carbon-limited. Incoming dissolved phosphorous and ammonia became incorporated in the natural wetland growth cycle that included periods of net removal and release, resulting in minimal annual net removal. In summary, this study shows that improving nitrate removal in a slow-flowing MTF wetland would require some kind of carbon dosing, while further improving ammonia and phosphorus removal would require a reduction of the amounts of ammonia and dissolved phosphorus entering the wetland.

Dissolved organic carbon (DOC) is essential to balance the metabolic demands of four dominant North‐Atlantic deep‐sea sponges

AbstractSponges are ubiquitous components of various deep‐sea habitats, including cold water coral reefs, and form deep‐sea sponge grounds. Although the deep sea is generally considered to be a food‐limited environment, these ecosystems are known to be hotspots of biodiversity and carbon cycling. To assess the role of sponges in the carbon cycling of deep‐sea ecosystems, we studied the carbon budgets of six dominant deep‐sea sponges of different phylogenetic origin, with various growth forms and hosting distinct associated microbial communities, in an ex situ aquarium setup. Additionally, we determined biomass metrics—planar surface area, volume, wet weight, dry weight (DW), ash‐free dry weight, and organic carbon (C) content—and conversion factors for all species. Oxygen (O2) removal rates averaged 3.3 ± 2.8 μmol O2 g DWsponge h−1 (mean ± SD), live particulate (bacterio‐ and phytoplankton) organic carbon removal rates averaged 0.30 ± 0.39 μmol C g DWsponge h−1 and dissolved organic carbon (DOC) removal rates averaged 18.70 ± 25.02 μmol C g DWsponge h−1. Carbon mass balances were calculated for four species and revealed that the sponges acquired 1.3–6.6 times the amount of carbon needed to sustain their minimal respiratory demands. These results indicate that irrespective of taxonomic class, growth form, and abundance of microbial symbionts, DOC is responsible for over 90% of the total net organic carbon removal of deep‐sea sponges and allows them to sustain themselves in otherwise food‐limited environments on the ocean floor.

Billion-year exposure ages in Gale crater (Mars) indicate Mount Sharp formed before the Amazonian period

The erosion rates and mechanisms operating on Mount Sharp in Gale crater, Mars were assessed via experiments performed by the SAM instrument to determine the cosmogenic noble gas contents of Murray mudstone formation samples Mojave 2 and Quela. Previous measurements of samples from the Aeolis Palus depression between Mount Sharp and the north rim of Gale crater indicate that scarp retreat-generated surfaces formed within the last 100 Ma. In contrast, Mojave 2 yielded exposure ages of 1,320±240 (3He), 910±420 (21Ne), and 310±60 Ma (36Ar). Quela gave a 3He age of 1,460±200 Ma; 21Ne and 36Ar from this sample could not be quantified due to isobaric interferences. The discordant and young 36Ar exposure age in Mojave 2 is likely the result of interaction with water which dissolved the chlorine-bearing host phases of this nuclide. The most probable exposure scenario is that both Mojave 2 and Quela have been at the surface for the most recent ∼1 Ga after the overlying few meters of rock were removed in a geologically rapid exhumation episode. Based on local geomorphology, scarp retreat is the most likely mechanism for the exposure at these two sites. The exposure ages measured throughout Curiosity's traverse indicate that the net removal of rock has proceeded more recently on Aeolis Palus than on the lower slopes of Mount Sharp. The implied differential erosion rate is insufficient to explain how Mount Sharp formed, even over billions of years. Instead, given that the surfaces on Mount Sharp have existed for >1 Ga, the mountain must have formed early, likely during the Hesperian. This study provides direct quantitative support for inferences based on crater counts that Mount Sharp had eroded to close to its current form before onset of the Amazonian.

Ultrafiltration in critically ill patients treated with kidney replacement therapy.

Management of fluid overload is one of the most challenging problems in the care of critically ill patients with oliguric acute kidney injury. Various clinical practice guidelines support fluid removal using ultrafiltration during kidney replacement therapy. However, ultrafiltration is associated with considerable risks. Emerging evidence from observational studies suggests that both slow and fast rates of net fluid removal (that is, net ultrafiltration (UFNET)) during continuous kidney replacement therapy are associated with increased mortality compared with moderate UFNET rates. In addition, fast UFNET rates are associated with an increased risk of cardiac arrhythmias. Experimental studies in patients with kidney failure who were treated with intermittent haemodialysis suggest that fast UFNET rates are also associated with ischaemic injury to the heart, brain, kidney and gut. The UFNET rate should be prescribed based on patient body weight in millilitres per kilogramme per hour with close monitoring of patient haemodynamics and fluid balance. Dialysate cooling and sodium modelling may prevent haemodynamic instability and facilitate large volumes of fluid removal in patients with kidney failure who are treated with intermittent haemodialysis, but the effects of this strategy on organ injury are less well studied in critically ill patients treated with continuous kidney replacement therapy. Randomized trials are required to examine whether moderate UFNET rates are associated with a reduced risk of haemodynamic instability, organ injury and improved outcomes in critically ill patients.

Constraining the Global Ocean Cu Cycle With a Data‐Assimilated Diagnostic Model

AbstractCopper (Cu) is a biologically important trace metal for marine plankton, but it is also toxic at high concentrations. Understanding the global distribution of Cu and the processes controlling its cycling in the ocean is important for understanding how the distribution of this important element can respond to climate change. Here, we use available observations of dissolved copper, an artificial neural network, and an ocean circulation inverse model, to derive a global estimate of the three‐dimensional distribution and cycling of dissolved Cu in the ocean. We find that there is net removal by bio‐assimilation and/or scavenging of dissolved Cu in the surface ocean at a rate of ~1.7 Gmol yr−1 and that both the concentration and export of dissolved Cu are highest in the Southern Ocean. In the subsurface above the near‐sediment layer, dissolved Cu is removed at a net rate of ~2.4 Gmol yr−1, consistent with scavenging onto sinking particles, contributing to an increase in the flux of particulate Cu with depth. This removal of Cu by scavenging in the interior ocean is balanced by a net near‐sediment source of dissolved Cu, which sustains a gradual increase in the concentration of dissolved Cu with depth. Globally, this net near‐sediment source is estimated at ~2.6 Gmol yr−1 in the deep ocean and ~0.8 Gmol yr−1 along continental shelves and slopes. Our results suggest an active oceanic dissolved Cu cycle with a mean internal ocean residence time of ~530 years, highlighting the potential for climate‐driven changes in the marine Cu cycle.

Small-scale biochar production on Swedish farms: A model for estimating potential, variability, and environmental performance

Several small-scale pyrolysis plants have been installed on Swedish farms and uptake is increasing in the Nordic countries. Pyrolysis plants convert biomass to biochar for agricultural applications and syngas for heating applications. These projects are driven by ambitions of achieving carbon dioxide removal, reducing environmental impacts, and improving farm finances and resilience. Before policy support for on-farm pyrolysis projects is implemented, a comprehensive environmental evaluation of these systems is needed. Here, a model was developed to jointly: (i) simulate operation of on-farm energy systems equipped with pyrolysis units; (ii) estimate biochar production potential and its variability under different energy demand situations and designs; and (iii) calculate life cycle environmental impacts. The model was applied to a case study farm in Sweden. The farm’s heating system achieved net carbon dioxide removal through biochar carbon sequestration, but increased its impact in several other environmental categories, mainly due to increased biomass throughput. Proper dimensioning of heat-constrained systems is key to ensure optimal biochar production, as biochar production potential of the case farm was reduced under expected climate change in Sweden. To improve the environmental footprint of future biochar systems, it is crucial that expected co-benefits from biochar use in agriculture are realised. The model developed here is available for application to other cases.

Formation of crystal-rich, mixed, intermediate lavas at Pouakai Volcano and the evolution of the Taranaki volcanic lineament, western North Island, New Zealand

Over the past ~2 Ma, volcanic activity in the western North Island of New Zealand has been focused along the NW to SE-younging Taranaki volcanic lineament (TVL). Geophysical imaging of the convergent boundary between the Pacific and Indo-Australian plates shows that the subducted slab lies at least ~200 km below the present TVL and the <200 ka andesitic Mt. Taranaki. Pouakai is the second youngest (~0.25 Ma) volcanic edifice of the TVL and lies immediately NW of Mt. Taranaki. It is deeply eroded with limited exposure, but it has been sampled by a major collapse event that generated the 0.21–0.24 Ma Maitahi debris avalanche deposit. The Pouakai lavas sampled by the Maitahi deposit are medium-K, pyroxene-bearing basalts and amphibole- and pyroxene- bearing basaltic andesites and andesites. Plagioclase, clinopyroxene and amphibole are the dominant phenocryst phases. Olivine and orthopyroxene are rare. Compared to younger Mt. Taranaki lavas, the Pouakai volcanic rocks have lower K, P, Ba, Rb, Sr and Zr and higher Sc and V abundances, and they define subtly different trends on TiO2, MgO and K2O versus SiO2 variation diagrams. Most Pouakai eruptives are similar to the older ring plain debris avalanche deposits of Mt. Taranaki, but Pouakai summit lavas are compositionally similar to younger Mt. Taranaki eruptives. For the Pouakai sample suite, the geochemical trends and patterns are broadly consistent with control by fractional crystallisation (FC), or assimilation fractional crystallisation (AFC). However, textural and geochemical evidence indicates that the rocks are not representative of simple magmas related by a common liquid line of descent. Pouakai basaltic andesites and andesites are highly porphyritic and phenocrysts show complex zoning and disequilibrium reaction textures. Mg# [mol. MgO/(MgO + FeO)] of amphibole and clinopyroxene compositions vary beyond the range expected if the minerals had equilibrated with melts having bulk whole rock compositions. Furthermore, geothermobarometry based on amphibole and pyroxene compositions indicates that mafic phenocrysts in all rock types, as well as in individual samples, equilibrated with comparatively felsic melts over a wide range of pressures. Therefore, each lava sample represents a mixed magma, comprising felsic melts derived from a range of crustal and mantle sources hosting a complex, polybaric phenocryst assemblage. The whole rock compositions were derived through varying degrees of bulk fractionation of phenocryst phases with net removal of amphibole and clinopyroxene and consequent concentration of plagioclase phenocrysts.

Hemodialysis With the Quanta SC+: Efficacy and Safety of a Self-care Hemodialysis Machine

Rationale & ObjectiveMost patients with kidney failure receive hemodialysis 3 times per week in a facility. More frequent and longer duration dialysis prescriptions improve a number of key outcome measures. These prescriptions are best suited to self-care and home regimens. The Quanta SC+ hemodialysis system is a novel device with demonstrated ease of use for patients and health care practitioners through human factors testing. The primary objective of this study is to report the efficacy and safety of the SC+ system using conventional hemodialysis prescriptions.Study DesignNonrandomized observational study.Setting & ParticipantsPrevalent hemodialysis patients in 4 sites in the United Kingdom were recruited to switch from their current device to the SC+ system with no other changes to their prescription.InterventionsSC+ hemodialysis system.OutcomesEfficacy data were collected in terms of dialysis adequacy, urea reduction ratios, and net fluid removal accuracy.Results60 patients were enrolled in the study, resulting in 1,333 evaluable treatments. The threshold single-pool Kt/V of 1.2 was exceeded in 96.6% of treatments in patients receiving 3-times-weekly regimens, whereas the threshold standard Kt/V of 2.1 was exceeded in 94% of treatments and 97.6% of treatments in patients without significant residual kidney function. Ultrafiltration accuracy was determined by measuring net fluid removal and validated to be within acceptable limits. The adverse event profile during treatment was typical of hemodialysis. There were no serious adverse events.LimitationsFew patients on high-frequency treatment regimens were enrolled.ConclusionsThe SC+ system delivers safe and effective hemodialysis across a range of patients and dialysis prescriptions. It is one of the smallest systems available and has validated usability for patients to perform self-care safely with minimal training. This device may encourage patients to feel empowered to take on home hemodialysis, unlocking beneficial clinical and patient-reported outcomes associated with these modalities.

Performance and community structure dynamics of microbial electrolysis cells operated on multiple complex feedstocks

BackgroundMicrobial electrolysis is a promising technology for converting aqueous wastes into hydrogen. However, substrate adaptability is an important feature, seldom documented in microbial electrolysis cells (MECs). In addition, the correlation between substrate composition and community structure has not been well established. This study used an MEC capable of producing over 10 L/L-day of hydrogen from a switchgrass-derived bio-oil aqueous phase and investigated four additional substrates, tested in sequence on a mature biofilm. The additional substrates included a red oak-derived bio-oil aqueous phase, a corn stover fermentation product, a mixture of phenol and acetate, and acetate alone.ResultsThe MECs fed with the corn stover fermentation product resulted in the highest performance among the complex feedstocks, producing an average current density of 7.3 ± 0.51 A/m2, although the acetate fed MECs outperformed complex substrates, producing 12.3 ± 0.01 A/m2. 16S rRNA gene sequencing showed that community structure and community diversity were not predictive of performance, and replicate community structures diverged despite identical inoculum and enrichment procedure. The trends in each replicate, however, were indicative of the influence of the substrates. Geobacter was the most dominant genus across most of the samples tested, but its abundance did not correlate strongly to current density. High-performance liquid chromatography (HPLC) showed that acetic acid accumulated during open circuit conditions when MECs were fed with complex feedstocks and was quickly degraded once closed circuit conditions were applied. The largest net acetic acid removal rate occurred when MECs were fed with red oak bio-oil aqueous phase, consuming 2.93 ± 0.00 g/L-day. Principal component analysis found that MEC performance metrics such as current density, hydrogen productivity, and chemical oxygen demand removal were closely correlated. Net acetic acid removal was also found to correlate with performance. However, no bacterial genus appeared to correlated to these performance metrics strongly, and the analysis suggested that less than 70% of the variance was accounted for by the two components.ConclusionsThis study demonstrates the robustness of microbial communities to adapt to a range of feedstocks and conditions without relying on specific species, delivering high hydrogen productivities despite differences in community structure. The results indicate that functional adaptation may play a larger role in performance than community composition. Further investigation of the roles each microbe plays in these communities will help MECs to become integral in the 21st-century bioeconomy to produce zero-emission fuels.

BECCS based on bioethanol from wood residues: Potential towards a carbon-negative transport and side-effects

Bioenergy with carbon capture and storage (BECCS) is gaining broad interest as an effective strategy to go beyond carbon neutrality. So far, most of the work on BECCS focused on power systems, while its application to the transport sector has received much less attention. To contribute to filling this gap, this work investigates the potential of BECCS as a carbon-negative strategy in the transport sector by applying process modelling and life cycle assessment (LCA) to bioethanol production from lignocellulosic waste. The process was analyzed following a cradle-to-wheel approach, i.e., from biomass growth to the combustion of biofuel in the cars, assuming that the CO2 emitted in the fermentation and cogeneration units is captured, compressed and transported to be stored permanently in geological sites. Several scenarios differing in the bioethanol-gasoline blends (10–85% bioethanol) were considered for a functional unit of 1 km of distance travelled, comparing with fossil-based gasoline. Our results show that blends above 85% (ethanol/gasoline) could have the potential to deliver a net-negative emissions balance of −2.74 kg CO2 eq per 100 km travelled and up to −5.05 kg CO2 eq per 100 km using a low carbon electricity source. The final amount of net CO2 removal is highly dependent on the carbon intensity of the electricity and the heating utilities. Biofuels blends could, however, lead to burden-shifting in eutrophication, ozone depletion and formation, toxicity, land use, and water consumption. This work highlights the potential of BECCS in the transport sector, and the need to analyze impacts beyond climate change in future studies to avoid shifting burdens to other categories.

Toward a national emission inventory for the catering industry in China

Catering oil fumes are a major hazard to human health. In particular, the typical Chinese cooking style is characterised by a high temperature frying process that produces high levels of cooking oil fumes. However, limited data relating to this sector mean that national emission inventory data specific to the catering service industry do not exist. To address above deficiency and thus to establish the inventory of a city, or a province, or even a country, a door-to-door survey campaign was launched in the Chinese cities of Heze and Linfen to determine the structure of local catering industries. Data revealed that the number of catering businesses per 104 people was 17 ± 4. Of these, 3.0 ± 1.4, 15.0 ± 1.4, and 82.0 ± 0.0% were classified as large, medium, and small enterprises, respectively. Furthermore, the installation rates of fume purifiers were 74 ± 13, 66 ± 9, and 51 ± 14% for large, medium, and small enterprises, respectively, with net removal efficiencies of 63 ± 11, 50 ± 7, and 31 ± 8%, respectively. This information was extrapolated across all provincial regions of China to construct a provincial and national emission inventory. In 2017, China's national catering industry released approximately 34 kt of volatile organic compounds (VOCs), 38 kt of particulate matter with a diameter less than 2.5 μm (PM2.5), 48 kt of particulate matter with a diameter less than 10 μm (PM10), 1 kt of black carbon (BC), and 27 kt of organic carbon (OC). A significant correlation was observed between vegetable oil consumption and emissions (e.g., for VOCs, y = 14.94 x + 76.50, R2 = 0.87, where y is VOCs emissions and x is vegetable oil consumption), indirectly corroborating the rationality of the inventory. Moreover, this correlation provides the potential for a dynamic inventory based on vegetable oil consumption. Future studies are proposed to address more influential factors to improve the reliability of the national inventory and refer to big data, rather than door-to-door investigation, to identify the amount of catering service businesses in a region.

Flow balance optimization and fluid removal accuracy with the Quanta SC+ hemodialysis system

ABSTRACT Background Fluid management is integral to hemodialysis, both to correct abnormalities in a patient’s plasma composition and to maintain fluid balance. Consequently, accurate net fluid removal during treatment is a critical design element of hemodialysis machines. As dialyzers have evolved, with increased ranges of ultrafiltration coefficients available, it has become more challenging for dialysis machines to minimize errors in flow balance and net fluid removal. Research design and methods This paper describes the design, evaluation and experimental performance of the flow balance and ultrafiltration module of the SC+ system to deliver clinically specified fluid removal with both passive and active control measures, in laboratory conditions designed to simulate a wide range of therapies. Results The use of passive and active control allows the errors to be minimized across a wider dynamic range of conditions. For the SC+ system, the average flow balance error was 1 mL/hr with an SD of 19 mL/hr and with ultrafiltration it was 13 mL/hr and an SD of 20 ml/hr across all conditions. Conclusions This paper demonstrates that the SC+ hemodialysis system, a small, simple and versatile CE marked device, operates within the limits required by international standards across a wide range of experimental conditions.

Potassium Fertilisation Is Required to Sustain Cassava Yield and Soil Fertility

Cassava is often grown in low-fertility soils and has a reputation for having modest nutrient requirements. The storage roots that are harvested, however, contain relatively large amounts of potassium (K). We carried out a field experiment in Laos to determine the growth response to K fertiliser and to examine the field’s K balance over the cropping season. Four different rates of K (0-40-80-120 kg K2O equivalents ha−1) were applied to cassava variety Rayong11. Harvests were done at 8 and 10 months after planting, when the crop was at early and full maturity respectively, to assess if any benefits for productivity or K balance could be achieved by early harvest. We found a positive effect of K fertiliser (up to 39% yield increase compared to no K fertiliser at early harvest, 21% at late harvest) and a positive effect of late harvest (on average a 35% increase compared to early harvest) on cassava root yield. Low-K crops benefited more from a late harvest. At 10 months, the harvested cassava contained 99–142 kg K ha−1, indicating that there was a net removal of K from the fields, even at high K fertilisation levels. This experiment was carried out in comparatively fertile soil with relatively high background K levels, yet, yield benefits of K fertilisation were observed and soil K reserves were depleted by the harvest. It can be concluded that K fertilisation of cassava is advisable for better yields and to avoid progressive depletion of the soil K capital.

P0637SAFETY, EFFICACY AND OUTCOMES OF SLOW LOW EFFICIENCY DIALYSIS (SLED) IN CRITICALLY ILL PATIENTS WITH ACUTE KIDNEY INJURY (AKI) IN MEDICAL INTENSIVE CARE UNITS (ICU)- A PROSPECTIVE STUDY IN A TERTIARY CARE HOSPITAL IN INDIA

Abstract Background and Aims Slow low efficiency dialysis (SLED) is increasingly being used as a renal replacement therapy in hemodynamically unstable, critically ill patients with acute kidney injury (AKI). SLED may reduce intradialytic hemodynamic instability as compared with conventional intermittent haemodialysis, while reducing resource demands of continuous renal replacement therapies (CRRT). There are very few studies which have evaluated its safety, efficacy and outcome despite its increasing use, especially in Indian subcontinent. Method We conducted a single centre, prospective study to demonstrate safety, efficacy and outcome of SLED.. Net fluid removal and duration of SLED were based on need and hemodynamic status of the individual patient as decided by treating nephrologist. SOFA score was used as severity illness score. Efficacy of SLED was studied in terms of ability to achieve ultrafiltration goal, correction of acidosis and urea reduction ratio. Safety was studied in terms of hemodynamic and cardiovascular stability and complications during and after SLED. Outcomes were noted at time of discharge and six months later in terms of dialysis dependence, renal parameters (if dialysis independent) and mortality (In hospital and 6 months following discharge). We included hemodynamically unstable patients with AKI from medical ICUs with age &amp;gt;18 years of either gender. We excluded patients with AKI who could tolerate conventional haemodialysis or ESRD on maintenance haemodialysis. Results We analysed 228 patients with AKI in medical ICUs who underwent 576 SLED sessions over period of six months. Mean age was 57.48 ± 15.67 years and 74% (n=169) were male. Comorbidities were hypertension (56%), diabetes mellitus (43%), CKD (33%) and cardiovascular diseases (28%). Sepsis (93%) and hypoperfusion (68%) were most common causes for AKI. Refractory fluid overload (91%) and refractory metabolic acidosis (79%) were most common indications for SLED. Mean SOFA score was 12.2 ± 7.75 with 61 % patients had SOFA score more than 11. 66% were on mechanical ventilator. Out of 576 sessions, 555 sessions (96%) completed the planned duration without any adverse event. Planned ultrafiltration goal was achieved in 94%. SLED was able to correct metabolic acidosis in majority (86.1%). 68% SLED sessions required a vasopressor support and 34.8 % of SLED sessions were associated with hemodynamic instability. Total 14(6.2 %) patients died during SLED session. No documented arrhythmias developed after starting SLED. In-hospital mortality occurred in 61% patients. At 6 months follow up, another 13% patients died. In subgroup analysis, mortality was significantly higher in patients with SOFA score more than 11 (P&amp;lt;0.0001). Ventilatory requirement was also significantly high in non-survivors(P&amp;lt;0.0001). Univariate logistic regression analysis showed that inotropic requirement, higher SOFA severity score, acidosis with pH &amp;lt;7.25 and presence of underlying CKD were associated with significant mortality. Conclusion Our study demonstrated efficacy and safety of SLED in critically ill AKI patients in medical ICU. SLED was able to achieve planned ultrafiltration goal and correct metabolic acidosis in majority of patients. SLED had good hemodynamic tolerability. Mortality was noted in 61 % of patients (not attributable to SLED per se). High SOFA score, underlying co morbidities, vasopressor requirement and severe acidosis (pH &amp;lt;7.25) were associated with high mortality. SLED is a reasonable cost-effective option of RRT in hemodynamically unstable patients with AKI especially in developing countries.

P1516DEMONSTRATION OF FLUID REMOVAL ACCURACY USING THE SC+ HAEMODIALYSIS SYSTEM

Abstract Background and Aims Fluid management is an integral component for managing patients to correct abnormalities in plasma composition and maintain fluid balance. Consequently, accurate fluid removal during treatment is a critical design element of haemodialysis machines. The SC+ haemodialysis system developed by Quanta Dialysis Technologies, is a small, simple-to-use dialysis system designed to improve patient access to self-care and home haemodialysis. This paper describes the design, evaluation and performance of the flow balance and ultrafiltration module of SC+ to deliver specified fluid removal in accordance with the international technical standards for haemodialysis defined in IEC 60601-2-16 using a number of unique proprietary technologies. Method SC+ uses volumetric flow balancing chambers which are contained within a single use disposable cartridge. During normal operation of SC+, dialysis fluid flows through the cartridge in discrete packets. This is achieved by the application of pneumatic pressure and vacuum to manipulate a flexible PVC membrane that, in turn, opens and closes a sequential series of valves and pump cavities that constitute the flow balance chambers. Proof of system performance was undertaken using a range of dialysers and venous pressures, with and without ultrafiltration, to quantify the net fluid removal error, in order to simulate a range of patient conditions in typical clinical practice. Results In total, the tests comprised 22 separate runs on multiple machines, with 88 individual 30-minute measurement samples, taken over a range of environmental conditions, dialyser types (with differing KuF), dialysate flowrates, and venous pressures. Across all results, there was a mean error of 7.4g/hour rate error, (max allowed is 100g/hr) of positive flow from the blood to the dialysate side with a standard deviation of 19.88g/hr. The maximum permissible rate stated in IEC 60601-2-16 is +/-100g/hr. In specific detail, without ultrafiltration the flow balance error was measured as 2.2g/hr with a deviation of 19.0g/hr, and with ultrafiltration the mean error was 12.8g/hr with a standard deviation of 19.5g/hr. Conclusion It has been demonstrated that flow balance error and fluid removal attainable with the SC+ haemodialysis system lies well within the acceptable standards permitted for haemodialysis machines. This essential performance parameter as defined within IEC 60601-2-16 has been demonstrated across a range of clinically relevant parameters at dialysate flow rates of up to 500ml/min