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Membranes Jun 2024Achieving sustainability in life involves increasing efforts to recover resources. This research proposes the recovery of Zn from the Milluni lagoons, an important water...
Achieving sustainability in life involves increasing efforts to recover resources. This research proposes the recovery of Zn from the Milluni lagoons, an important water supply for Bolivia, where high concentrations of Zn have been identified that exceed permitted limits, exposing a risk to health and ecosystems. The application of reverse osmosis (RO), operated with low pressures, is proposed as a first stage for the concentration of Zn and subsequent recovery of this metal through chemical precipitation. The aim was to maintain the separation efficiency of the RO operated at low pressures without presenting operational problems. As a result, 98.83% metal concentration was achieved with a laboratory-scale pilot system. The above means an important potential for large-scale Zn concentration, apart from orienting the RO toward sustainability by working with low pressures that reduce energy costs during its operation. This study can be used as a valuable reference for the advancement of sustainable technologies in the field of water treatment that simultaneously allow the recovery of resources to promote a circular economy. Finally, this study exposes an alternative for regions with heavy metal water contamination in Bolivia and worldwide.
PubMed: 38921498
DOI: 10.3390/membranes14060131 -
Membranes May 2024To date, life support systems on the International Space Center (ISS) or those planned for upcoming moon/Mars missions have not included biological reactors for...
To date, life support systems on the International Space Center (ISS) or those planned for upcoming moon/Mars missions have not included biological reactors for wastewater treatment, despite their ubiquitous use for the treatment of terrestrial wastewaters. However, the new focus on partial gravity habitats reduces the required complexity of treatment systems compared with those operating in micro-gravity, and the likely addition of large-volume wastewaters with surfactant loads (e.g., laundry and shower) makes the current ISS wastewater treatment system inappropriate due to the foaming potential from surfactants, increased consumable requirements due to the use of non-regenerative systems (e.g., mixed adsorbent beds), the complexity of the system, and sensitivity to failures from precipitation and/or biological fouling. Hybrid systems that combine simple biological reactors with desalination (e.g., Reverse Osmosis (RO)) could reduce system and consumable mass and complexity. Our objective was to evaluate a system composed of a membrane-aerated bioreactor (MABR) coupled to a low-pressure commercial RO system to process partial gravity habitat wastewater. The MABR was able to serve as the only wastewater collection tank (variable volume), receiving all wastewaters as they were produced. The MABR treated more than 20,750 L of graywater and was able to remove more than 90% of dissolved organic carbon (DOC), producing an effluent with DOC < 14 mg/L and BOD < 12 mg/L and oxidizing >90% of the ammoniacal nitrogen into NOx. A single RO membrane (260 g) was able to process >3000 L of MABR effluent and produced a RO permeate with DOC < 5 mg/L, TN < 2 mg/L, and TDS < 10 mg/L, which would essentially meet ISS potable water standards after disinfection. The system has an un-optimized mass and volume of 128.5 kg. Consumables include oxygen (~4 g/crew-day), RO membranes, and a prefilter (1.7 g/crew-day). For a one-year mission with four crew, the total system + consumable mass are ~141 kg, which would produce ~15,150 kg of treated water, resulting in a pay-back period of 13.4 days (3.35 days for a crew of four). Given that the MABR in this study operated for 500 days, while in previous studies, similar systems operated for more than 3 years, the total system costs would be exceedingly low. These results highlight the potential application of hybrid treatment systems for space habitats, which may also have a direct application to terrestrial applications where source-separated systems are employed.
PubMed: 38921494
DOI: 10.3390/membranes14060127 -
Membranes May 2024The removal of dissolved organic matter (DOM) from seawater before the reverse osmosis (RO) processes is crucial for alleviating organic fouling of RO membranes....
The removal of dissolved organic matter (DOM) from seawater before the reverse osmosis (RO) processes is crucial for alleviating organic fouling of RO membranes. However, research is still insufficiently developed in the comparison of the effectiveness of integrating coagulation with ultrafiltration (UF) or sand filtration (SF) in the pretreatment stage of seawater reverse osmosis (SWRO) for the removal of DOM. In this study, we investigated the effect of pretreatment technologies on RO fouling caused by DOM in seawater, including the integration of coagulation and sand filtration (C-S pretreatment) and the integration of coagulation and ultrafiltration (C-U pretreatment). Both integrated pretreatments achieved comparable DOM removal rates (70.2% for C-U and 69.6% for C-S), and C-S exhibited enhanced removal of UV-absorbing compounds. Although C-U was more proficient in reducing the silt density index (below 2) compared to C-S (above 3) and improved the elimination of humic acid-like organics, it left a higher proportion of tyrosine-protein-like organics, soluble microbial by-product-like organics, and finer organics in the effluent, leading to the formation of a dense cake layer on RO membrane and a higher flux decline. Therefore, suitable technologies should be selected according to specific water conditions to efficiently mitigate RO membrane fouling.
PubMed: 38921492
DOI: 10.3390/membranes14060125 -
Pediatric Investigation Jun 2024Critically ill children with pre-existing mental health conditions may have an increased risk of poor health outcomes.
IMPORTANCE
Critically ill children with pre-existing mental health conditions may have an increased risk of poor health outcomes.
OBJECTIVE
We aimed to evaluate if pre-existing mental health conditions in critically ill pediatric patients would be associated with worse clinical outcomes, compared to children with no documented mental health conditions.
METHODS
This retrospective observational cohort study utilized the TriNetX electronic health record database of critically ill subjects aged 12-18 years. Data were analyzed for demographics, pre-existing conditions, diagnostic, medication, procedural codes, and mortality.
RESULTS
From a dataset of 102 027 critically ill children, we analyzed 1999 subjects (284 [14.2%] with a pre-existing mental health condition and 1715 [85.8%] with no pre-existing mental health condition). Multivariable analysis demonstrated that death within one year was associated with the presence of pre-existing mental health conditions (odds ratio 8.97 [3.48-23.15], < 0.001), even after controlling for the presence of a complex chronic condition.
INTERPRETATION
The present study demonstrates that the presence of pre-existing mental health conditions was associated with higher odds of death within 1 year after receiving critical care. However, the confidence interval was wide and hence, the findings are inconclusive. Future studies with a larger sample size may be necessary to evaluate the true long-term impact of children with pre-existing mental health conditions who require critical care services.
PubMed: 38910847
DOI: 10.1002/ped4.12422 -
Journal of Environmental Management Jun 2024In this study, treated wastewater and Multi-Stage Flash (MSF) brine were integrated into the Forward Osmosis (FO) system using pressure stimuli-responsive Nanofiltration...
In this study, treated wastewater and Multi-Stage Flash (MSF) brine were integrated into the Forward Osmosis (FO) system using pressure stimuli-responsive Nanofiltration (PSRNF) membranes to dilute magnesium, calcium, and sulfate MSF plant brine reject. The deposition of magnesium sulfate and calcium sulfate in the heat exchanger is one of the main issues affecting the performance and efficiency of MSF thermal desalination plants. Reducing the concentration of the divalent ions can minimize scale formation and deposition to a level that allows the MSF plant to operate at high top brine temperature (TBT) and without scale problems. The PSRNF membranes were chosen in the FO process because of their high water permeability, rejection of divalent and monovalent ions, small structure parameter (S), and inexpensiveness compared to commercial FO membranes. Three PSRNF membranes were tested in the FO process with the feed solution facing the active membrane layer to avoid active layer delamination. Although the PSRNF membrane exhibited negligible water flux at 0 bar, it increased when a 2-4 bar was applied to the feed solution. The wastewater temperature was set at 25 °C while 40 °C was the brine operational temperature to mimic the field situation. A maximum average water flux of 39.5 L/mh was recorded at 4 bar feed pressure when the PSRNF membrane was used for the brine dilution, achieving up to 42% divalent ions dilution at 0.02 kWh/m specific power consumption. The average water flux in the PRSNF membrane was 35% higher than that in the commercial TFC FO membrane. Notably, the PSRNF membrane is ten times cheaper than commercial FO membranes. Notably, the PSRNF membrane is ten times cheaper than commercial FO membranes, achieving substantial cost reductions and pioneering advancements in FO purification technology.
PubMed: 38908153
DOI: 10.1016/j.jenvman.2024.121517 -
The Science of the Total Environment Jun 2024Reverse osmosis (RO) plays a pivotal role in shale gas wastewater resource utilization. However, managing the reverse osmosis concentrate (ROC) characterized by high...
Reverse osmosis (RO) plays a pivotal role in shale gas wastewater resource utilization. However, managing the reverse osmosis concentrate (ROC) characterized by high salinity and increased concentrations of organic matter is challenging. In this study, we aimed to elucidate the enhancement effects and mechanisms of pre-ozonation on organic matter removal efficacy in ROC using a biological activated carbon (BAC) system. Our findings revealed that during the stable operation phase, the ozonation (O and O/granular activated carbon)-BAC system removes 43.6-72.2 % of dissolved organic carbon, achieving a 4-7 fold increase in efficiency compared with that in the BAC system alone. Through dynamic analysis of influent and effluent water quality, biofilm performance, and microbial community structure, succession, and function prediction, we elucidated the following primary enhancement mechanisms: 1) pre-ozonation significantly enhances the biodegradability of ROC by 4.5-6 times and diminishes the organic load on the BAC system; 2) pre-ozonation facilitates the selective enrichment of microbes capable of degrading organic compounds in the BAC system, thereby enhancing the biodegradation capacity and stability of the microbial community; and 3) pre-ozonation accelerates the regeneration rate of the granular activated carbon adsorption sites. Collectively, our findings provide valuable insights into treating ROC through pre-oxidation combined with biotreatment.
PubMed: 38906281
DOI: 10.1016/j.scitotenv.2024.174080 -
Chemosphere Jun 2024Electro-osmosis offers an effective method for dewatering and remediating low permeability soil. Long-term observations on nonlinear behavior of electro-osmosis and the...
Electro-osmosis offers an effective method for dewatering and remediating low permeability soil. Long-term observations on nonlinear behavior of electro-osmosis and the influencing factors are not commonly reported. Connection between cessation and direction reversal of electro-osmotic flow (EOF), and the evolution of electro-chemical parameters inside of the soil mass thus remains unclear. The dynamic response of EOF in variable charge soil could be significant, whereas the investigations on which are currently lacking. A series of electro-osmotic experiments were performed with two natural variable charge soils. The results indicated that initial electro-osmotic rate was positively proportional to electric current and initial electrical conductivity of the pore fluid, which could be explained by the ion migration model. The dynamic evolution of electro-osmotic rate and electro-chemical parameters corresponding to the solute and pH conditionings at the electrode compartments demonstrated that: 1) coupling effects of non-uniform distribution of voltage gradient and pH determined the magnitude and direction of EOF rate; 2) compared to the final pH value, the bigger, close and smaller values of the novel index "voltage gradient weighed mean of spatial pH " represented the forward, terminated and reversed EOF respectively; 3) the classical Helmholtz-Smoluchowski model are proved to be more applicable interpreting the coupled nonlinearity of electro-osmosis during the later steady phase. This work would facilitate future research for a comprehensive electro-osmotic model, and provide guidance to condition the initial and boundary conditions in application of electro-osmotic dewatering and electrokinetic remediation.
PubMed: 38906191
DOI: 10.1016/j.chemosphere.2024.142661 -
Environmental Science and Pollution... Jun 2024The agricultural sector uses 70% of the world's freshwater. As clean water is extracted, groundwater quality decreases, making it difficult to grow crops. Brackish water...
The agricultural sector uses 70% of the world's freshwater. As clean water is extracted, groundwater quality decreases, making it difficult to grow crops. Brackish water desalination is a promising solution for agricultural areas, but the cost is a barrier to adoption. This study investigated the performance of the fertilizer drawn forward osmosis (FDFO) process for brackish water desalination using response surface methodology (RSM) and artificial neural network (ANN) approaches. The RSM model was used to identify the optimal operating conditions, and the ANN model was used to predict the water flux (J) and reverse solute flux (J). Both models achieved high accuracy, with RSM excelling in predicting J (R = 0.9614) and ANN performing better for J (R = 0.9801). Draw solution (DS) concentration emerged as the most critical factor for both models, having a relative importance of 100% for two outputs. The optimal operating conditions identified by RSM were a DS concentration of 22 mol L, and identical feed solution (FS) and DS velocities of 8.1 cm s. This configuration yielded a high J of 4.386 LMH and a low J of 0.392 gMH. Furthermore, the study evaluated the applicability of FDFO for real brackish groundwater. The results confirm FDFO's potential as a viable technology for water recovery in agriculture. The standalone FO system proves to be less energy-intensive than other desalination technologies. However, FO exhibits a low recovery rate, which may necessitate further dilution for fertigation purposes.
PubMed: 38904877
DOI: 10.1007/s11356-024-34011-4 -
Water Research Jun 2024A large amount of organophosphorus-containing wastewater is produced in spent lithium-ion battery disposal. Forward osmosis (FO) offers unique advantages in purifying...
A large amount of organophosphorus-containing wastewater is produced in spent lithium-ion battery disposal. Forward osmosis (FO) offers unique advantages in purifying this kind of wastewater if suitable draw solutes - the core of FO technology, are available. Herein we synthesize several pH-sensitive zinc complexes, namely ZnATMP-iNa (i = 0, 1, 2, 3, 4), from ZnSO and amino tris(methylene phosphonic acid) (ATMP) obtained from scale inhibitor wastes for organophosphorus-containing wastewater remediation. Among these ZnATMP-iNa, ZnATMP-3Na best meets the standards of an ideal draw solute. This makes ZnATMP-3Na outperform other reported draw solutes. 0.6 M ZnATMP-3Na produces a water flux of 12.7 LMH, 136 % higher than that of NaCl and a solute loss of 0.015 g/L, lower than that of NHHCO (0.83 g/L). In organophosphorus-containing wastewater treatment, ZnATMP-3Na has higher water recovery efficiency (8.3 LMH) and sustainability than NaCl and NHHCO, and is sufficient to handle large quantities of wastewater. Remarkably, the pH-responsive property allows ZnATMP-3Na to be readily recovered through pH-control and reused in FO. The ionic property, expanded cage-like structure and easy-recycling make ZnATMP-3Na achieve sustainable FO separation and superior to other draw solutes. This study provides inspiration for draw solute design from wastes and extends FO application to organophosphorus-containing wastewater remediation.
PubMed: 38901308
DOI: 10.1016/j.watres.2024.121939 -
Lab on a Chip Jun 2024We combine two-photon-excited fluorescence microscopy and acoustofluidic trapping in a spherical microchamber to study cells and cell clusters three-dimensionally close...
We combine two-photon-excited fluorescence microscopy and acoustofluidic trapping in a spherical microchamber to study cells and cell clusters three-dimensionally close to conditions. The two-photon microscopy provides the in-depth 3D analysis of the spherical microchamber dimensions as well as the positions of trapped samples therein with high spatial precision and high temporal resolution enabling even tracking of the fast moving particles. Furthermore, optical sectioning allows to gather information of individual cells in trapped cell clusters inside the chamber. We demonstrate real-time monitoring of osmosis in A549 lung cells and red blood cells as one possible biomedical application. The observed osmosis reduced the cell membrane diameter by approximately 4 μm in the A549 cells and by approximately 2 μm in the red blood cells. Our approach provides an important optical tool for future investigations of cell functions and cell-cell interactions avoiding wall-contact inside an acoustofluidic device.
PubMed: 38895892
DOI: 10.1039/d4lc00144c