Preparation and properties of a metal-organic frameworks polymer material based on Sa-son seed gum capable of simultaneously absorbing liquid water and water vapor.

Atmospheric water harvesting (AWH) technology has attracted significant attention as an effective strategy to tackle the global shortage of freshwater resources. Work has focused on the use of hydrogel-based composite adsorbents in water harvesting and water conservation. The approaches adopted to make use of hygroscopic inorganic salts which subject to a "salting out" effect. In this study, we report the first use of modified UIO-66-NH2 as a functional steric cross-linker and Sa-son seed gum was used as polymeric substrate to construct super hygroscopic hydrogels by free radical copolymerization. The maximum water uptake on SMAGs (572 cm3·g-1) outperforms pure UIO-66-NH2 (317 cm3·g-1). Simultaneously, our first attempt to use it for anti-evaporation applications in an arid environment (Lanzhou, China) simulating sandy areas. The evaporation rate of the anti-evaporation material treated with 0.20 % super moisture-absorbent gels (SMAGs) decreased by 6.1 % over 64 h period under natural condition in Lanzhou, China. The prepared material can not only absorb liquid water but also water vapor, which can provide a new way for water collection and conservation technology. The design strategy of this material has wide applications ranging from atmospheric water harvesting materials to anti-evaporation technology.

Alpine ecosystem response to climate warming: Long-term monitoring data of stream chemistries revisited.

Alpine ecosystems are considered to be more sensitive to climate change than are downstream habitats because they exhibit less resilience to climate warming. Long-term monitoring of stream chemistries serves as a powerful tool to discern environmentally driven changes, in the context of cryospheric processes. According to the research hypothesis, the chemistry trends in the Green Lakes Valley, Colorado Front Range resulted from bedrock weathering in response to permafrost thawing coupled with exogenous sources. The median pH values during the 36 years of monitoring (1984-2020) have increased significantly in all five sampling sites from the headwater (5.7 at ~3800 m a.s.l) to the outlet (6.9 at ~3345 m a.s.l). The ANC increased significantly from a median of 10.6 µeq L-1 at the headwater to a median of 129 µeq L-1 at the outlet. These trends have occurred in spite of high sulfate concentrations in meltwater generated by oxidative weathering of pyrite (OWP). Analysis of the major cations and anions in the downstream sites revealed fairly consistent multi-segment trends. The first segment from 1984 to the mid 1990s exhibited a slight decrease in the electrolytes concentrations. Remarkably rapid upswings in electrolyte concentrations were observed in the mid 1990s to the mid 2000s. However, these trends significantly decreased from the mid 2000s onward. If climate warming is the mechanism that controls the rate of mineral weathering, then the electrolytes release rates from meltwater and permafrost thawing should increase over time, rather than flatten off or even decrease, as observed here. These spatiotemporal patterns of calcium and sulfate can be explained by a combination of mineral weathering and exogenous additions. Permafrost thawing is an important mechanism that adversely affects the OWP; consequently, it releases sulfuric acid and increases mineral weathering. However, the influence of eolian dust on alpine stream chemistry should not be overlooked.

Biological reconditioning of sodium enriched zeolite by halophytes: case study of dairy farm effluent treatment.

Constructed wetlands (CW) containing clinoptilolite zeolite and planted with five halophytes (Sesvium portulacastrum, Juncus effusus, Suaeda monoica, Inula crithmoides and Sarcocornia fruticosa) were irrigated with treated dairy farm effluent. The CW were operated for two years with retention time ranging from 2 to 7 d. Plant species did not affect SAR which was reduced in all treatments from 4.85 to 2.59 (mmol/L)0.5 due to ion exchange in zeolite. Halophytes increased evapotranspiration to 30 mm d-1 which countered sodium removal. Zeolite planted with Sesuvium portulacastrum had 15% lower sodium percentage (ESP, F1,118 = 12.53, p = 0.0006) and 5% higher calcium percentage (F1,118 = 7.44, p = 0.007) compared to non-planted zeolite, indicating reconditioning of zeolite with respect to sodium. Enhancement of SAR removal capability by reconditioned zeolite was demonstrated in 24 h batch experiments on excavated zeolite (n = 6) with saline water (SAR = 0, 17.6, 62.8, and 122.8 (mmol/L)0.5). Zeolite from Sesuvium planted CW reduced SAR to a greater extent than non-planted zeolite and was significant for inlet SAR 17.6 which was reduced to 3.33 ± 0.3 (mmol/L)0.5 compared to 3.68 ± 0.12 by non-planted zeolite (p < 0.05). In-situ biological reconditioning of active matrix in CW by tailored macrophytes is a novel strategy that may be applicable to other pollutants.

Assessing modified aluminum-based water treatment residuals as a plant-available phosphorus source.

Inorganic phosphorus (P) fertilizers are a finite resource; alternative means of creating P fertilizers from current municipal and agricultural waste sources may reduce our reliance on phosphate rock mining, and improve waste disposal and nutrient cycling. Previous research demonstrated that organic aluminum water treatment residual composites (Al/O-WTR), created by mixing aluminum water treatment residuals (Al-WTR) with swine wastewater, have the potential to be a source of plant-available P. A greenhouse study was conducted to compare spring wheat (Triticum aestivum L.) growth with increasing application rates of swine wastewater-derived Al/O-WTR and commercial P fertilizer (both applied at 34, 67, and 135 kg P2O5 ha-1) in either sandy loam or sandy clay loam soil. Spring wheat straw and grain P uptake were comparable across all treatments in the sandy loam, while straw and grain P uptake were lower with Al/O-WTR in the sandy clay loam. The Al/O-WTR did not affect soil organic P concentrations, but did increase phosphatase activity in both soils. Increased phosphatase activity suggests that Al/O-WTR application stimulated microorganisms and enhanced the extent to which microbial communities mineralized Al/O-WTR-bound organic P. Overall, these results suggest that Al-WTR can be used to make P fertilizer, combining two "waste" products to create a useful product. Phosphorus harvesting via Al/O-WTR may be a feasible future alternative to mining phosphate rock, while avoiding unnecessary waste disposal and improving agricultural nutrient cycling.

Phosphorus Sorption Characteristics in Aluminum-based Water Treatment Residuals Reacted with Dairy Wastewater: 1. Isotherms, XRD, and SEM-EDS Analysis.

We examined P sorption characteristics in Al-based water treatment residuals (Al-WTR) generated from slightly alkaline surface water and in an organic residual composite (WW-Al/O-WTR), produced by using the Al-WTR to treat organic-rich and high P concentration dairy wastewater. Solids from both residuals were examined using scanning electron microscopy-energy dispersive spectroscopy (SEM-EDS) and X-ray diffraction (XRD), and exposed to P additions of 0 to 4000 mg L in a sorption experiment. The Al-WTR removed ∼97% of the added P, whereas WW-Al/O-WTR removed only 78% of the added P in the addition range of 0 to 100 mg P L. With P additions of ≥100 mg L, the removal rate declined to <38% by Al-WTR and to 16% by WW-Al/O-WTR, possibly implying a change in sorption mechanisms. Analysis by XRD indicated that the major mineral was calcite, with some silica and poorly crystalline Al hydroxides. Analysis by SEM-EDS, which used three-element overlay maps of the residual surfaces, indicated that P was sparsely sorbed on both calcic and Al (hydr)oxide surfaces, along with a few clusters, even at low P concentrations of the treated waters. Ternary clusters of P, Al, and Ca were more abundant on the WW-Al/O-WTR. Carbon distribution suggested that organic substances covered Al surfaces. Sorption of P onto WW-Al/O-WTR may be reversible due to relatively weak Ca-P and Al-P bonds induced by the slight alkaline nature and in the presence of organic moieties, enhancing the WW-Al/O-WTR potential to act as a P source, rather than a P sink, in agricultural applications.

Phosphorus Sorption to Aluminum-based Water Treatment Residuals Reacted with Dairy Wastewater: 2. X-Ray Absorption Spectroscopy.

Phosphorus capture from wastewater can decrease water pollution and provide a P-rich fertilizer alternative for use in agricultural production. This study was conducted to elucidate P retention mechanisms in Al-based water treatment residuals (Al-WTR) to gain insight regarding P sorption and the potential for P release from Al-WTR after reaction with dairy wastewater. Synchrotron-based microfocused X-ray fluorescence (micro-XRF) spectrometry, bulk P -edge X-ray absorption near edge structure spectroscopy (XANES), and P -edge micro-XANES spectroscopy were used to determine P distribution and speciation within the Al-WTR materials. Bulk XANES analyses indicated a shift from ∼56 P atom % Ca-associated P in the initial Al-WTR to ∼32% P atom % Ca-associated P after reaction with wastewater; Al-associated P made up the remainder of the P species. According to XANES analyses, adsorption appeared to be the primary P retention mechanism in the Al-WTR materials. However, micro-XANES analyses depicted a more complicated picture of P retention mechanisms, with regions of primarily Al-associated P, regions of primarily Ca-associated P, regions of mixed Al- and Ca-associated P, and distinct apatite- or octocalcium phosphate-like P grains. Synchrotron micro-XRF mapping further suggested that exposure of the aggregate exteriors to wastewater caused P to diffuse into the porous Al-WTR aggregates. Organic P species were not explicitly identified via P -edge XANES despite high organic matter content, suggesting that organic P may have been predominantly associated with mineral surfaces. Although diffusion and sorption to Al may decrease P bioavailability, Ca-associated P may increase P bioavailability from Al-WTR that is reused as a soil amendment.

The impact of olive mill wastewater spreading on soils using integrated approach of proximal soil survey, spatial, and multivariate analyses.

Olive oil production generates a large amount of olive mill wastewater (OMW), the most difficult to treat of agro-industrial effluents. Spreading of OMW across the soilscape has become the most frequently used practice in several Mediterranean basin countries but is hotly debated because of its potential to impair soil environs. The research hypothesis states that soil deterioration is correlated strongly with the spatiotemporal rate of OMW application; thus, the spatial pattern of the soil attributes should be established in conjunction with the rate of OMW spreading. The spatial pattern was ascertained using proximal soil sensing that measures the apparent electrical conductance (ECa). Eight representative locations were identified using grouping analysis of the ECa data. The soils were analyzed for selected physical and chemical attributes known to be affected by OMW spreading as well as ancillary parameters needed for the calibration of the ECa. Discriminant analysis successfully categorized 76% of the ECa groups, selecting CEC, sand, pH, and ESP as the most powerful discriminatory variables in the grouping analysis. The correlation coefficients between the measured ECa, and the calculated ECa, and soil moisture were very high (r > 0.77, P < 0.05), suggesting that the proximal soil survey results are well calibrated. The spreading of untreated OMW over more than 7 years did not impair the soils under study. No significant changes in soil chemo-physical properties such as pH (< 7.66), electrical conductivity in saturated paste (< 3.58 dS m-1), sodium adsorption ratio (< 2.3), potassium adsorption ratio (< 0.33), exchangeable sodium percentage (< 3.85%), and unsaturated hydraulic conductivity (< 0.3 cm h-1) were found in comparison with untreated soils. The results support the premise that moderate quantities of OMW (50-70 m3 ha-1 year-1) equally spread over the soilscape will have little impact on soil health.

Evaluation of the ornithogenic influence on the trophic state of East Mediterranean wetland ecosystem using trend analysis.

The Great Rift Valley portion of the East African-Eurasian Migratory Flyway is extremely important globally because of the numbers (>500 million) and diversity of seasonal traveling birds. The construction of the Agmon wetland (1.1km(2)) in the Hula Valley, Israel in 1994 and a change in crop type and rotation has attracted increasing number of Eurasian cranes (Grus grus) to winter in the wetland (>40,000 in 2014). The birds are fed in an area of 100ha and roost during the night in the wetland for protection from predators. Feeding practices have yielded an eco-tourism bonanza with over 400,000 visitors annually. However, this practice may have negative impacts on the trophic state of the wetland. We performed trend analyses using monthly means of selected constituents collected from mid-1994 to 2014. The temporal distribution of TN and TP concentrations in the inlets did not change with time. The concentrations of TN and TP in the outlet increased significantly during the earlier monitoring period. Kendall-Theil regression showed that TP concentrations in the outlet increased significantly from a monthly mean of 180µgL(-1) in 2010 to a monthly mean of 260µgL(-1) in 2014. Similarly, the results of chlorophyll a concentrations in the outlet showed a sharp upturn in the latter part of the series from a mean of 66mgL(-1) in 2010 to a mean of 122mgL(-1) in 2014. The concurrent increase of TP and chlorophyll a, the two most important parameters affecting a waterbody trophic index coincided with the observed increase in the number of roosting cranes in the wetland. Hence, we assume that the continued increases in TP concentrations could transform the wetland from a mild eutrophic to a permanent hypereutrophic state. Reducing the number of roosting cranes may prevent this from happening.

The impact of ornithogenic inputs on phosphorous transport from altered wetland soils to waterways in East Mediterranean ecosystem.

Large flocks of Eurasian crane (Grus grus, >35,000) have begun wintering in an altered wetland agro-ecosystem located in Northern Israel, a phenomenon that attracts more than 400,000 eco-tourists a year. A 100-ha plot has been used to feed the cranes in order to protect nearby fields. The objective of this study was to evaluate the influence of this bird's feeding practice on the P status of the altered wetland soils and waterways. We installed a series of wells at two depths (40 and 90 cm) between two major waterways in the feeding area and monitored the hydraulic heads and collected groundwater samples for elemental analyses. We collected six soil cores and four sediment samples from the waterways and conducted sequential P extraction. We found significant increase in groundwater soluble reactive P (SRP) (>0.5 mg l(-1)) compared with much lower concentrations (~0.06 mg l(-1)) collected in the period prior to the feeding. We found significant decrease in Fe((II)), Ca, and SO4 concentrations in the shallow groundwater (33, 208, and 213 mg l(-1), respectively) compared with the period prior to the feeding (47, 460, and 370 mg l(-1) respectively). An increase in the more labile P fraction was observed in soils and sediments compared with the period before the feeding. The P input by bird excrement to the feeding area was estimated around 700 kg P per season, while P removal by plant harvesting was estimated around 640 kg Pyr(-1). This finding supports the current eco-tourism practices in the middle of intensive farming area, suggesting little impact on waterways.