This study theoretically analyzes the concept of apparent saturation hysteresis, combined with the Scott et al. (1983) scaling approach, as suggested by Parker and Lenhard (1987), to account for the effect of air entrapment and release on the soil water hysteresis. We found that the theory of Parker and Lenhard (1987) is comprised of some mutually canceling mathematical operations, and when cleared of the superfluous intermediate calculations, their model reduces to the original Scott et al.’s (1983) scaling method, supplemented with the requirement of closure of scanning loops. Our analysis reveals that actually there is no effect of their technique of accounting for the entrapped air on the final prediction of the effective saturation (or water content) scanning curves. Our consideration indicates that the use of the Land (1968) formula for assessing the amount of entrapped air is in disaccord with the apparent saturation concept as introduced by Parker and Lenhard (1987). In this paper, a proper routine is suggested for predicting hysteretic scanning curves of any order, given the two measured main curves, in the complete hysteretic domain and some verification tests are carried out versus measured results. Accordingly, explicit closed-form formulae for direct prediction (with no need of intermediate calculation) of scanning curves up to the third order are derived to sustain our analysis. © 2018 Elsevier Ltd

Significant concerns have been raised up due to the presence of organic micropollutants in surface waters. The ability of two polymer-clay sorbents based on a functionalized cationic starch was examined for the removal of three pharmaceuticals: atenolol, sulfamethoxazole and diclofenac sodium. In batch experiments, the complex which exhibited a planar conformation of the polymer on the clay surface and higher cationic charge density showed higher sorption of diclofenac and sulfamethoxazole over those of the composite with a loops and tails configuration, but similar with atenolol. The introduction of functional moieties on the polymers that are capable to create a network of hydrogen-bonds with the pollutants promoted their removal as revealed by thermal and infrared techniques: diclofenac molecules formed an ion pair including hydrogen bonds through their secondary amine groups; sulfamethoxazole sorbed by strong electrostatic interactions followed by proton transfer involving its sulphon-nitrogen group and the hydroxyl moieties of the composite. Filtration experiments showed a better performance of the columns made of the composite with higher cationic charge density on the removal of diclofenac and sulfamethoxazole over that of granular activated carbon. The filtration processes were successfully modeled by using an adsorption-convection model which enabled predictions under different operational conditions used in drinking water plants. Experimental removal of diclofenac by filtration within the range found in environmental concentrations was in good agreement with the predicted amounts. © 2018

{The present report is a review of uses of quaternary ammonium cations (QACs) as free monomers or immobilized in micelle-clay complexes in bacteria removal from water. The removal of bacteria from water by filtration through a bed of a granulated QAC-clay micelle was improved by minute concentrations of QAC that were released from the complex during filtration, which exerted biostatic or biocidal effects on the bacteria that emerged from the filter. The relationships between antibacterial activity (minimum inhibition concentration, MIC; minimum lethal concentration, MLC) and structural parameters of the QACs (head group size and alkyl chain length) are discussed. The antibacterial activity of QACs in aqueous phases is mainly due to the free monomeric species. Bacterial inactivation is enhanced by QACs with longer alkyl chains. In most recorded cases, however, minimum MIC and MLC values occurred at n =14 16 and mostly at n = 16, where n is the number of C atoms in the alkyl chain. This outcome is explained by the combination of two antagonistic effects: (i) An increase in alkyl chain length (i.e., QAC hydrophobicity) enhances QAC binding, penetration, and destabilization of bacterial membranes; and (ii) an increase in alkyl chain length lowers the critical micelle concentration (CMC) of QACs and, thus, reduces QAC monomer concentrations, which more efficiently inactivate bacteria than the micelles. The octadecyltrimethylammonium (ODTMA

Irrigation with treated wastewater (TWW) and application of biosolids to arable land expose the agro-environment to pharmaceuticals and personal care products (PPCPs) which can be taken up by crops. In this project, we studied the effect of a carrier medium (e.g., biosolids and TWW) on plant (tomato, wheat and lettuce) uptake, translocation and metabolism of carbamazepine as a model for non-ionic PPCPs. Plant uptake and bioconcentration factors were significantly lower in soils amended with biosolids compared to soils irrigated with TWW. In soils amended with biosolids and irrigated with TWW, the bioavailability of carbamazepine for plant uptake was moderately decreased as compared to plants grown in soils irrigated with TWW alone. While TWW acts as a continuous source of PPCPs, biosolids act both as a source and a sink for these compounds. Moreover, it appears that decomposition of the biosolids in the soil after amendment enhances their adsorptive properties, which in turn reduces the bioavailability of PPCPs in the soil environment. In-plant metabolism of carbamazepine was found to be independent of environmental factors, such as soil type, carrier medium, and absolute amount implemented to the soil, but was controlled by the total amount taken up by the plant. Bioavailability of PPCPs originated from biosolids amendment is lower than the bioavailability of those introduced by irrigation with treated wastewater. © 2017 Elsevier Ltd

Soil vulnerability to heavy metal pollution is low in soils exhibiting an ability to strongly adsorb heavy metals on their geochemical fractions. Organic matter (OM) is among other components of soils, one of the most effective sorbing fractions. Compost addition is often used for soil remediation thereby enriching the soil with OM. However, compost is often enriched with heavy metals and thereby may induce adverse effects on the soil and plants growing in them. Compost-derived dissolved organic matter (DOM) can mobilize heavy metals. The balance between two contrasting effects of compost—mobilization and immobilization of heavy metals—was studied under the conditions of adsorption–desorption batch experiment. Metal adsorption to different geochemical fractions of soil treated with compost was examined by a combined batch-adsorption experiment and a sequential extraction procedure. Compost-derived DOM mobilized Cu at low loading levels, whereas adsorption of Cd and Pb was not decreased by DOM application. Compost was found to be a source of an important reducible oxides fraction (RO—sorbing and fixation fraction) and also of the OM geochemical fractions that most commonly immobilizes heavy metals. The Langmuir and Freundlich models employed in our study exhibited a good fit for most of data the experimental data obtained on bulk samples. Adsorption of the metals on operationally defined geochemical fractions was described by a linear function in several experimental instances. © 2018, Springer-Verlag GmbH Germany, part of Springer Nature.

Pressure-irrigation systems and, in particular, micro-irrigation provide an effective methodology for increasing irrigation efficiency. However, emitter clogging is a major problem in micro-irrigation systems, especially under irrigation with treated wastewater (TWW). Currently, farmers treat their irrigation system by periodical application of solutions of chemicals or washing the lateral lines. The aim of this study was to characterize treatments for the prevention of clogging in drip irrigation systems utilizing different qualities of TWW (secondary and tertiary TWW). A model system was designed and assembled to compare the flow rate (FR), fouling accumulation and fouling composition in laterals and drippers subjected to different treatments. Under irrigation with secondary TWW, control treatment function decreased rapidly while chemical treatment prolonged proper function of the drippers by maintaining a normal FR and coefficient of variation (CV). Wash treatment improved to some extent the irrigation function. Under irrigation with tertiary TWW the function of all treatments was significantly better than that of the secondary treatments. The total suspended solids level was found to be a significant factor in the mechanism of clogging formation according to biofouling development. The deposit chemical characterization could shed light on the mode of growth mechanism and properties of the biofouling. In general, oxidation treatments using hydrogen peroxide or hypochlorite acid were found to eliminate biofouling and in accordance also prevented clogging. © 2018, Springer-Verlag GmbH Germany, part of Springer Nature.

Water desalination has been extensively developed in Israel, particularly in the last decade. The desalination process provides fresh water that typically lacks minerals, and among these are ions that are essential to human health and/or to agricultural production, such as Mg. We analyzed 28 tap water samples originating from different cities across Israel to document their concentrations of Mg and other elements. The data from this survey (summer 2016) were compared with the results of similar observations conducted in 2008. Regarding toxic elements, tap water across Israel does not pose any health risk for consumers and may be used as drinking water without any household pretreatment. This condition has not changed since 2008. However, the problem of Mg deficiency due to the use of desalinated water was observed in about half of the sampling locations in 2016, whereas no Mg deficiency had been detected in 2008. Moreover, household filtration of tap water prior to consumption as drinking water may worsen the situation due to the Mg status resulting from rejection of this ion; this could be harmful to the consumer, particularly under prolonged exposure. © 2017 Elsevier B.V.

Utilizing treated wastewater (TWW) for irrigation results in biological and chemical deposits. TWW components such as bacteria and suspend minerals interact under different environmental conditions, forming aggregates varying in size and stability that may adversely affect water flow in drippers. Our aim in this study was to characterize aggregates’ size and stability in suspensions of bacteria and clay particles, under different conditions prevailing in TWW. Flocculation value tests, thermal analysis, microscopy and particle size distribution were used to measure bacterial–clays interaction in suspension. Our results showed suspension stability increase with an increase in bacterial population. Dissolved organic carbon (DOC) produced by bacteria or added as fulvic acid was found to be the most important parameter involved in determining aggregate size and stability under similar environmental condition. The presence of these components most commonly resulted in higher stability of the suspension, mainly smaller particles in suspension. A novel measurement aimed to determine size and stability parameters for suspended particles has been established and was found to be useful in predicting suspended compound interactions. © 2018, Springer-Verlag GmbH Germany, part of Springer Nature.

Composting in closed polyethylene sleeves with forced aeration may minimize odor emissions, vectors attraction and leachates associated with open windrows. The present study demonstrates the use of this system for composting olive mill wastewater (OMW), the undesired stream associated with the olive milling industry. A polyethylene sleeve of 1.5-m diameter and ca. 20-m long was packed with shredded municipal green waste which was pre-soaked in OMW for 72 h. Process conditions were controlled by means of a programmable logic controller (PLC) equipped with temperature and oxygen sensors. Thermophilic temperatures (>45 °C) were maintained for one month followed by temperatures in the range of 30–40 °C, ca. 20 °C above ambient temperature, for a period of 3.5 months. Oxygen levels were controlled and the system was kept aerobic. Water content gradually decreased with sufficient levels for efficient composting. The finished compost was non-phytotoxic to Cress (Lepidium sativum L.) in a lab bioassay. It was also found suitable as an ingredient in peat, tuff, and coir based growing media, evaluated by plant growth tests with basil and ornamental plants. The viability of this approach for disposing off OMW is much dependent on the liquid absorption capacity of the vegetative waste. © 2018 Elsevier Ltd

Irrigation with treated waste water (TWW) is a common practice in agriculture, mainly in arid and semiarid areas as it provides a sustainable water resource available at all-season in general and at freshwater shortage in particular. However, TWW still contains abundant organic material which is known to decrease soil wettability, which in turn may promote flow instabilities that lead to the formation of preferential flow paths. We investigate the impact of long-term TWW irrigation on water wettability and infiltration into undisturbed soil cores from two commercially used orchards in Israel. Changes of water content during infiltration were quantitatively analysed by X-ray radiography. One orchard (sandy clay loam) had been irrigated with TWW for more than thirty years. In the other orchard (loamy sand) irrigation had been changed from freshwater to TWW in 2008 and switched back in some experimental plots to freshwater in 2012. Undisturbed soil cores were taken at the end of the dry and the rainy season to investigate the seasonal effect on water repellency and on infiltration dynamics in the laboratory. The irrigation experiments were done on field moist samples. A test series with different initial water contents was run to detect the influence on water movement at different wettabilities. In this study we show that the infiltration front stability is dependent on the history of waste water irrigation at the respective site and on the initial water content.

Regulation of the rate of transpiration is an important part of plants' adaptation to uncertain environments. Stomatal closure is the most common response to severe drought. By closing their stomata, plants reduce transpiration to better their odds of survival under dry conditions. Under mild to moderate drought conditions, there are several possible transpiration patterns that balance the risk of lost productivity with the risk of water loss. Here, we hypothesize that plant ecotypes that have evolved in environments characterized by unstable patterns of precipitation will display a wider range of patterns of transpiration regulation along with other quantitative physiological traits (QPTs), compared to ecotypes from less variable environments. We examined five accessions of wild barley (Hordeum vulgare ssp. spontaneum) from different locations in Israel (the B1K collection) with annual rainfall levels ranging from 100 to 900?mm, along with one domesticated line (cv. Morex). We measured several QPTs and morphological traits of these accessions under well-irrigated conditions, under drought stress and during recovery from drought. Our results revealed a correlation between precipitation-certainty conditions and QPT plasticity. Specifically, accessions from stable environments (very wet or very dry locations) were found to take greater risks in their water-balance regulation than accessions from areas in which rainfall is less predictable. Notably, less risk-taking genotypes recovered more quickly than more risk-taking ones once irrigation was resumed. We discuss the relationships between environment, polymorphism, physiological plasticity and fitness, and suggest a general risk-taking model in which transpiration-rate plasticity is negatively correlated with population polymorphism.

Dry deposition of ozone (O3) to vegetation is an important pathway for its removal from the troposphere, and it can lead to adverse effects in plants and changes in climate. However, our mechanistic understanding of O3 dry deposition is insufficient to adequately account for it in global and regional models, primarily because this process is highly complicated by feedback mechanisms and sensitivity to specific characteristics of vegetative environment and atmospheric dynamics and composition. We hypothesized that measuring dry deposition of O3 to vegetation near the Eastern Mediterranean (EM) coast, where large variations in meteorological conditions and photochemical air pollution frequently occur, would enable identifying the mechanisms controlling O3 deposition to vegetation. Moreover, we have only limited knowledge of O3 deposition to vegetation occurring near a coastline, under air pollution, or in the EM. This study investigated O3 deposition to mixed Mediterranean vegetation between the summers of 2015 and 2017, 3.6 km away from the EM coast, using the eddy covariance technique to quantify vertical flux of O3 and its partitioning to stomatal and non-stomatal flux, concurrent with nitrogen oxide (NOx), sulfur dioxide and carbon monoxide. Surprisingly, nighttime O3-deposition velocity (Vd) was smaller than daytime Vd by only ~20–37% on average for all measurement periods, primarily related to moderate nighttime atmospheric stability due to proximity to the seashore. We provide evidence for the role of sea-salt aerosols in enhancing O3 deposition via surface-wetness buildup at low relative humidity near the coast, and for daytime enhancement of O3 deposition by the combined effects of biogenic volatile organic compound emission and surface-wetness buildup. We further show that NOx emitted from elevated emission sources can reduce O3 deposition, and even lead to a positive O3 flux, demonstrating the importance of adequately taking into account the impact of air pollution on O3 deposition to vegetation.

Abstract Ecosystem evapotranspiration (ET) can approach annual precipitation (P) often leaving a residual [P-ET], referred to as an ecosystem water yield (WYe). Using a mobile lab, we estimate ET and WYe, in paired forest and nonforest (shrub or grassland) sites along the precipitation gradient (285?755 mm a?1) in Israel. WYe was 69 mm in the dry sites and was further reduced by ?51 mm by forestation. Both WYe and the impact of forestation increased in the wetter sites, with forestation reducing WYe by >200 mm, equivalent to ?30% of the local P. This was associated with increase in ET by a factor of 2.2 and 1.8 in the forest and nonforest sites, respectively, along the rainfall gradient. Losses in WYe due to forestation approached a maximum of ?200 mm above P ? 500 mm, but the forest WYe could vary between ?300 mm at P?=?900 mm and ?100 mm at P?=?500 mm (with equivalent change in WYe between 500 and 300 mm in the nonforest sites), reflecting the increasing ?hydrological cost? associated with vegetation ET and the expected climate change in these regions. The results quantify the interactions of land use and climate on ecosystem ET, indicating that in dry climates, afforestation impact on WYe varies significantly across small spatial scales and can reduce WYe with significant impacts on local hydrology. Such impact may be diminished by management (e.g., plant species, thinning, and grazing) but should also consider the trade-offs with other ecosystem services (e.g., carbon sequestration, soil protection, and surface cooling).

Carbamazepine and lamotrigine prescribed antiepileptic drugs are highly persistent in the environment and were detected in crops irrigated with reclaimed wastewater. This study reports pharmacokinetics of the two drugs and their metabolites in cucumber plants under hydroponic culture, testing their uptake, translocation, and transformation over 96 h in single and bisolute systems at varying pH. Ruling out root adsorption and transformations in the nutrient solution, we demonstrate that carbamazepine root uptake is largely affected by the concentration gradient across the membrane. Unlike carbamazepine, lamotrigine is adsorbed to the root and undergoes ion trapping in root cells thus its translocation to the shoots is limited. On the basis of that, carbamazepine uptake was not affected by the presence of lamotrigine, while lamotrigine uptake was enhanced in the presence of carbamazepine. Transformation of carbamazepine in the roots was slightly reduced in the presence of lamotrigine. Carbamazepine metabolism was far more pronounced in the shoots than in the roots, indicating that most of the metabolism occurs in the leaves, probably due to higher concentration and longer residence time. This study indicates that the uptake of small nonionic pharmaceuticals is passive and governed by diffusion across the root membrane.Carbamazepine and lamotrigine prescribed antiepileptic drugs are highly persistent in the environment and were detected in crops irrigated with reclaimed wastewater. This study reports pharmacokinetics of the two drugs and their metabolites in cucumber plants under hydroponic culture, testing their uptake, translocation, and transformation over 96 h in single and bisolute systems at varying pH. Ruling out root adsorption and transformations in the nutrient solution, we demonstrate that carbamazepine root uptake is largely affected by the concentration gradient across the membrane. Unlike carbamazepine, lamotrigine is adsorbed to the root and undergoes ion trapping in root cells thus its translocation to the shoots is limited. On the basis of that, carbamazepine uptake was not affected by the presence of lamotrigine, while lamotrigine uptake was enhanced in the presence of carbamazepine. Transformation of carbamazepine in the roots was slightly reduced in the presence of lamotrigine. Carbamazepine metabolism was far more pronounced in the shoots than in the roots, indicating that most of the metabolism occurs in the leaves, probably due to higher concentration and longer residence time. This study indicates that the uptake of small nonionic pharmaceuticals is passive and governed by diffusion across the root membrane.