Water Deposition Research Articles

Spatial Distributions, Compositional Profiles, Potential Sources, and Intfluencing Factors of Microplastics in Soils from Different Agricultural Farmlands in China: A National Perspective.

More attention has been paid to ubiquitous microplastics (MPs). As a major food producer, the situation of MPs in China's farmland is of even greater concern. Spatial distributions, characteristics, and compositions of MPs in five types of agricultural lands with representative crops were investigated by collecting 477 soil samples from 109 cities in 31 administrative regions of mainland China. To better control MPs in farmland, nearly 400 field questionnaires were obtained, and meteorological conditions, soil properties, and other statistics were collected to quantify potential sources and determine influencing factors. The average abundances of MPs was 2462 ± 3767 items/kg in the agricultural soils, and MP abundance in the greenhouses, farmlands with film mulching, and blank farmlands from four integrated physical geographic regions were determined. The contributions of agricultural films, livestock and poultry manures, irrigation water, and air deposition to MPs in farmlands have been calculated. Influencing factors, such as recovery method, plowing frequency, meteorological conditions, and part of soil properties, were significantly correlated with the abundances of MPs in the agricultural soils (p < 0.05), while mulching age mainly affected MPs in the greenhouses (p < 0.05). This study provides basic scientific data for decision-making and further analysis.

Fog Water, Throughfall, and Bulk Precipitation Chemistry and a Newly Developed Methodology for the Estimation of Fog Water Deposition

Fog Water, Throughfall, and Bulk Precipitation Chemistry and a Newly Developed Methodology for the Estimation of Fog Water Deposition

Assessing the Distribution of Water Ice and Other Volatiles at the Lunar South Pole with LUVMI-X: A Mission Concept

The search for exploitable deposits of water and other volatiles at the Moon’s poles has intensified considerably in recent years, due to the renewed strong interest in lunar exploration. With the return of humans to the lunar surface on the horizon, the use of locally available resources to support long-term and sustainable exploration programs, encompassing both robotic and crewed elements, has moved into focus of public and private actors alike. Our current knowledge about the distribution and concentration of water and other volatiles in the lunar rocks and regolith is, however, too limited to assess the feasibility and economic viability of resource-extraction efforts. On a more fundamental level, we currently lack sufficiently detailed data to fully understand the origins of lunar water and its migration to the polar regions. In this paper, we present LUVMI-X, a mission concept intended to address the shortage of in situ data on volatiles on the Moon that results from a recently concluded design study. Its central element is a compact rover equipped with complementary instrumentation capable of investigating both the surface and shallow subsurface of illuminated and shadowed areas at the lunar south pole. We describe the rover and instrument design, the mission’s operational concept, and a preliminary landing-site analysis. We also discuss how LUVMI-X fits into the diverse landscape of lunar missions under development.

Weather stressors correlate with Escherichia coli and Salmonella enterica persister formation rates in the phyllosphere: a mathematical modeling study

Enteric pathogens can enter a persister state in which they survive exposure to antibiotics and physicochemical stresses. Subpopulations of such phenotypic dormant variants have been detected in vivo and in planta in the laboratory, but their formation in the natural environment remains largely unexplored. We applied a mathematical model predicting the switch rate to persister cell in the phyllosphere to identify weather-related stressors associated with E. coli and S. enterica persister formation on plants based on their population dynamics in published field studies from the USA and Spain. Model outputs accurately depicted the bi-phasic decay of bacterial population sizes measured in the lettuce and spinach phyllosphere in these studies. Predicted E. coli persister switch rate on leaves was positively and negatively correlated with solar radiation intensity and wind velocity, respectively. Likewise, predicted S. enterica persister switch rate correlated positively with solar radiation intensity; however, a negative correlation was observed with air temperature, relative humidity, and dew point, factors involved in water deposition onto the phylloplane. These findings suggest that specific environmental factors may enrich for dormant bacterial cells on plants. Our model quantifiably links persister cell subpopulations in the plant habitat with broader physical conditions, spanning processes at different granular scales.

U-shaped plastic optical fiber sensor for scale deposition in hot spring water.

Fiber optic sensors for monitoring scale deposition in geothermal brine and hot spring water should be safe, easily fabricated, and readily disposable. These desired features already have been enhanced in plastic optical fibers (POFs) and U-shaped sensors for other applications. The present work reports a U-shaped POF sensor for CaCO3 scale deposition. The sensors were easily fabricated by thermally bending the bulk POF without removing the cladding. At the bend, the percentage of total internal reflection between the water and the POF surface is affected by the high refractive index of the CaCO3 deposit. The optical responses of the U-shaped sensor to CaCO3 formation were investigated in a mixture of calcium chloride dehydrate and sodium hydrogen carbonate using a white-light source and a spectroscopic detector. The sensor was responsive to CaCO3 formation on the sensor surface and was especially sensitive at small bending radii. The sensitivity was further enhanced by increasing the number of bends. Finally, the U-shaped POF sensor was applied to the monitoring of CaCO3 scale deposition in hot spring water sampled at Matsushiro, Japan.

Ontogenetic, dietary, and environmental shifts in Mesosauridae.

Mesosaurs are the first secondarily aquatic amniotes and one of the most enigmatic clades of reptiles from the early Permian. They have long puzzled paleontologists with their unique morphologies: possessing an elongated skull with thin needle-like teeth, a long neck, large webbed hindlimbs, banana-shaped pachyosteosclerotic ribs, and a long tail. Here, we look at a large dataset of morphometric measurements from 270 mesosaur specimens in collections around the world. These measurements characterize skull, tooth, and limb proportions and their variation with size. This data presents evidence of surprising ontogenetic changes in these animals as well as new insights into their taxonomy. Our results support the recent hypothesis that Mesosaurus tenuidens is the only valid species within Mesosauridae and suggest that “Stereosternum tumidum” and “Brazilosaurus sanpauloensis” represent immature stages or incomplete specimens of Mesosaurus by showing that all three species occupy an incomplete portion of the overall size range of mesosaurs. Under the single-species hypothesis, we highlight a number of ontogenetic trends: (1) a reduction in skull length accompanied by an elongation of the snout within the skull, (2) an elongation of teeth, (3) a reduction in hind limb length, and (4) a reduction in manus length. Concurrent with these changes, we hypothesize that mesosaurs went through a progressive ecological shift during their growth, with juveniles being more common in shallow water deposits, whereas large adults are more frequent in pelagic sediments. These parallel changes suggest that mesosaurs underwent a diet and lifestyle transition during ontogeny, from an active predatory lifestyle as juveniles to a more filter-feeding diet as adults. We propose that this change in lifestyle and environments may have been driven by the pursuit of different food sources, but a better understanding of the Irati Sea fauna will be necessary to obtain a more definitive answer to the question of young mesosaur diet.

Miniature semiconductor neutron spectrometer HardPix for surface mapping of lunar water

A current renaissance of lunar exploration enables to search for lunar water deposits directly on the surface of the Moon with robotic rovers. We present a novel miniature semiconductor neutron spectrometer capable of mapping the water deposits using non-invasive detection of neutrons created underground by cosmic rays and thermalized by hydrogen. This prospecting package consists of a radiation detector to monitor the cosmic rays background, a thermal/epithermal neutron detector to measure flux of neutrons moderated by water, and a gamma spectrometer suitable for monitoring local changes of major elemental components of the lunar regolith. Using miniature semiconductor detectors allows to deploy them even on small commercial rovers where resources are extremely limited. The prospecting package is being developed for ispace lunar rover and studied for ESA EL3 rover. It is based on Timepix pixel sensors, with space heritage onboard NASA, ESA and JAXA vessels.

Assessing microplastic characteristics in bottled drinking water and air deposition samples using laser direct infrared imaging

There is an urgent need for data on microplastics (MPs) in uptake media relevant to humans. Here we apply Laser Direct Infra-Red (LDIR) spectroscopy for the rapid analysis of MP> 10 µm in clean matrices such as bottled drinking water and (deposited) air samples, using strict QA/QC criteria. Nine water bottles of three different brands were found to contain on average 96 particles/L (range 7–364, median 44 particles/L) with polymer abundances in the order polyethylene terephthalate and/or polyurethane > polyamide > polyvinylchloride. Further, for laboratory and household rooms, MP deposition rates were measured, ranging from 0 to 573 particles m−2 h−1. For household deposition samples, these rates translate to 7 MP (range 0–16) consumed in an average meal. Polyethylene terephthalate and/or polyurethane > polyamide > polypropylene were the most abundant polymers. We find a statistically significant positive relationship between the total surface area of textile per unit of room volume (m2/m3) and the deposition of MP. Power law distributions for particle width, height, area, volume and mass were constructed for both sample types, with slopes ranging from 1.9 to 3.8. LDIR appears to be a relatively fast MP measurement method, with MP recovery during sample preparation as a potential improvement point.

Non-destructive preservation state estimation of waterlogged archaeological wooden artifacts

Non-destructive preservation state estimation is an essential prerequisite for the preservation and conservation of waterlogged archaeological wooden artifacts. Herein, Near Infrared (NIR) spectroscopy coupled with orthogonal partial least squares discriminant analysis (OPLS-DA) were applied to assess sixty-four waterlogged archaeological woods collected from seven excavation sites in the period range of 2900 BCE-1912 CE, aiming at developing a non-destructive, accurate and rapid preservation state estimation methodology. The role of non-decayed recent wood of relevant species on preservation state estimation was studied in prior, showing the use of non-decayed recent wood could not improve the predictive ability. Besides, the high variability in terms of chemical structure between archaeological softwoods and archaeological hardwoods did affect the preservation state estimation. Thus, a simple OPLS-DA model of non-destructively distinguishing archaeological hardwoods from softwoods, R2Xcum of 0.659, R2Ycum of 0.836 and Q2cum of 0.763, was established to avoid and overcome destructive approach for wood identification. Then, the well-defined three grouped separations of slightly-decayed, moderately-decayed and severely-decayed waterlogged archaeological woods were revealed in OPLS-DA models, providing R2Xcum of 0.793, R2Ycum of 0.738, Q2cum of 0.680, and R2Xcum of 0.780, R2Ycum of 0.901, Q2cum of 0.870, for waterlogged archaeological hardwoods and waterlogged archaeological softwoods respectively. Potential predictive wood spectral bands were screened and tentatively identified as hydroxyls of crystalline cellulose, acetyl groups of hemicelluloses, C-H bands of lignin, which guaranteed the elimination of non-structural compounds, such as water and inorganic components interference. Furthermore, the developed NIR methodology was validated by an extensively used destructive method consisting of anatomical characteristics, maximum water content and basic density analyses. The results indicated that NIR coupled to chemometrics could non-destructively and accurately predict the preservation states of waterlogged archaeological wooden artifacts and avoid the interference of water and inorganic deposits.

Glacial state of the global carbon cycle: time-slice simulations for the last glacial maximum with an Earth-system model

Abstract. Three time-slice carbon cycle simulations for the last glacial maximum (LGM) constrained by the CO2 concentration in the atmosphere and the increase in the mean concentration of dissolved inorganic carbon in the deep ocean were carried out with a fully coupled comprehensive climate model (the Community Earth System Model version 1.2). The three modelled LGM ocean states yielded different physical features in response to artificial freshwater forcing, and, depending on the physical states, suitable amounts of carbon and alkalinity were added to the ocean to satisfy constraints from paleo-data. In all the simulations, the amount of carbon added was in line with the inferred transfers of carbon among various reservoirs during the evolution from the LGM to the pre-industrial (PI) period, suggesting that the simulated glacial ocean states are compatible with the PI one in terms of the carbon budget. The increase in total alkalinity required to simulate ocean states that were deemed appropriate for the LGM was in broad quantitative accord with the scenario of post-glacial shallow water deposition of calcium carbonate, although a more precise assessment would demand further studies of various processes such as the land chemical weathering and deep-sea burial of calcium carbonates, which have affected the alkalinity budget throughout history since the LGM. On the other hand, comparisons between the simulated distributions of paleoceanographic tracers and corresponding reconstructions clearly highlighted the different water-mass geometries and favoured a shallower Atlantic meridional overturning circulation (AMOC) for the LGM as compared to PI.

Geochemical features of source rocks and oil in saline and freshwater lake environments: A case study in the southwest Qaidam Basin

The Qaidam Basin is a Cenozoic continental salt-lake basin in China. The lakes within this basin develop various salinities. This paper studies the geochemical characteristics of source rocks and petroleum in different salinity environments. Our results indicate that from the Paleogene to the Neogene, the salinity in the western Hongshi Sag gradually decreased and that the salinity in the eastern Zhahaquan Sag gradually increased, reflecting the eastward movement of the sedimentary center of the Paleogene basin. However, the salinities of western strata are still higher than those of the eastern strata. Due to the salinity differences between sedimentary water sources, the geochemical characteristics of source rocks and their products are also different. We can categorize these oils into two types according to their geochemical characteristics: Type A and Type B. Type A materials are produced around the Hongshi Sag and are the product of salt water deposition, while Type B materials are produced around the Zhahaquan Sag and are the products of freshwater deposition. Compared with Type B, Type A has the advantages of a high gamma paraffin index, a low Pr/Ph value, and a uniform carbon number of n-alkanes. Simultaneously, some geochemical parameters (Ts/Tm, OEP, Pr/Ph, etc.) lose their significance due to high salinity during formation. Geochemical differences between these sedimentary environments make it relatively easy to distinguish the source rocks for each type: Type A materials come from the E32 source rock in the Hongshi Sag and Type B materials come from the E32 source rock in the Zhahaquan Sag. This study is significant for revealing the geochemical characteristics of source rocks and crude oil, refining the law of oil and gas migration and further characterizing the sedimentary environment in Salt-Lake Basin.

Low oxygen seawater and major shifts in the paleoenvironment towards the terminal Ediacaran: Insights from the Portfjeld Formation, North Greenland

Earth’s environment during the diversification of metazoans in the Late Ediacaran was characterised, amongst other factors, by changing oxygen levels and an extreme negative carbon isotope (δ13C) excursion, the Shuram Excursion. The Portfjeld Formation, North Greenland, deposited in the Franklinian Basin of eastern Laurentia, presents a unique opportunity to investigate a previously geochemically unstudied succession of Ediacaran marine carbonates to better understand the environment at this time. The succession encompasses a δ13C excursion (from +4 to −8‰) comparable to the Shuram Excursion, as well as the Portfjeld Biota, fossils akin to the earliest putative metazoan life forms, the Weng’an Biota. We present a multiproxy geochemical study of 44 samples including rare earth element (and yttrium; REE + Y), chromium isotope (δ53Cr) and strontium isotope (87Sr/86Sr) compositions.The Portfjeld Formation reveals that low oxygen waters existed beneath oxic surface waters in a stratified early Franklinian Basin. Samples from an interval including bituminous cherty dolomites are enriched in cerium relative to its neighbouring REE+Y’s, expressed as positive cerium anomalies (Ce/Ce* = 1.15–1.38), as well the redox sensitive element molybdenum (EF(Mo) = 23–179). This indicates deposition in waters with active metal oxyhydroxide dissolution, which necessitates dissolved oxygen levels as low as <10 μM. This has potential implications for the habitable environment of early putative metazoan forms, as the Portfjeld Biota fossils are found in this interval.The δ53Cr composition of carbonates can be used to track redox related paleoenvironmental changes. A stratigraphic increase in the estimated authigenic δ53Cr composition (from +0.75 to +1.28‰) occurs throughout the nadir and recovery of the succession’s δ13C carbon excursion. This δ53Cr shift coincides with an increase in detrital element concentration and 87Sr/86Sr values. Therefore, in this instance the δ53Cr composition of the carbonates of the Portfjeld Formation appears to have responded to elevated on-land weathering, and thus nutrient input, which may have induced further fractionation associated with surface water Cr (VI) back reduction by primary producers, in line with modern ocean observations. These geochemical changes indicate that Ediacaran carbon isotope excursions may be tied to environmental shifts that eventually led to the dramatic increase in metazoan complexity that ensued.

Sea Ranching Feasibility of the Hatchery-Reared Tropical Sea Cucumber Stichopus monotuberculatus in an Inshore Coral Reef Island Area in South China Sea (Sanya, China)

Sea ranching of tropical edible sea cucumbers is an effective way to relieve the overfishing stress on their natural resources and protect the coral reef ecosystem, yet only a few species have been applied in the sea ranching practice based on hatchery-reared juveniles around the world. In this study, an 8-month (April to December) sea ranching study for hatchery-reared edible sea cucumber Stichopus monotuberculatus juveniles was carried out at a tropical coral reef island area in Sanya, China. Several growth performance indexes and basal nutritional components were monitored. Results revealed that the sea cucumbers had a growth rate of 0.35~0.78 mm day-1 during the experimental period, reaching 15.9 cm long before winter. The weight gain reached 491.13% at the end, and most sea cucumbers were able to grow to the commercial size (over 150 g WW) in the first year of sea ranching. The overall specific growth rate (SGR) and survival rates were 0.73 and 27.5%. Most of the death occurred in the first month after release (25.0%–37.5%), and this is probably due to inadaptation to the sudden change of the environment from the hatchery to the wild, which is proved by the remarkable decrease in nutritional indexes (amino acids, total lipid, and crude protein). Stable isotope and lipid biomarkers revealed that the food source mainly comes from water deposits (with microbes), Sargassum sanyaense seaweed debris, phytoplankton, and coral mucus-derived organics. The study proved the feasibility of the sea ranching of the hatchery-reared S. monotuberculatus juveniles in the tropical coral reef island area. Also, it is highly recommended that appropriate acclimation operation before release should be carried out to improve the survival rate of this species.

Valorization of Citrus reticulata (Mandarin) Waste in Inhibition of Scaling Deposit of Natural Hard Water, Electrochemical and Morphological Characterization

Valorization of Citrus reticulata (Mandarin) Waste in Inhibition of Scaling Deposit of Natural Hard Water, Electrochemical and Morphological Characterization

Validation of a mechanistic dynamic pre-weaned lamb growth and body composition simulation model

Lamb growth and body composition simulation models can provide valuable insights into the assessment of feeding regimens and rearing systems, allowing optimisation of farm profitability without the need for in-vivo trials. The objective of the present study was to evaluate the performance of a published mechanistic dynamic model on the growth and body composition of pre-weaned lambs using independently published data sets. Data generated from eight treatments, representing three artificial lamb rearing experiments (n = 77 lambs) were used. Initial body composition data were obtained from four lambs at approximately two days of age, with the remaining lambs being provided with defined nutritional treatments until the trial end-point. The body composition of lambs at slaughter was determined in six treatments across two experiments. Feed intake and live weight (LW) of lambs were recorded in all treatments. The LW, average daily gain (ADG) and ash deposition rates of lambs were accurately simulated by the model (paired t-test, P > 0.05). The overall empty body weight (EBW), gutfill, protein and fat deposition rates were overestimated, and water deposition rate was underestimated by the model (paired t-test, P < 0.05). Collectively, these results suggest that the model can be used at the farm level with acceptable accuracy to determine lamb growth. Further improvements in the model are required for protein, fat and water deposition rates, gutfill and EBW to make it more applicable for wider usage.

Freeform 3D Ice Printing (3D-ICE) at the Micro Scale.

Water is one of the most important elements for life on earth. Water's rapid phase‐change ability along with its environmental and biological compatibility also makes it a unique structural material for 3D printing of ice structures reproducibly and accurately. This work introduces the freeform 3D ice printing (3D‐ICE) process for high‐speed and reproducible fabrication of ice structures with micro‐scale resolution. Drop‐on‐demand deposition of water onto a −35 °C platform rapidly transforms water into ice. The dimension and geometry of the structures are critically controlled by droplet ejection frequency modulation and stage motions. The freeform approach obviates layer‐by‐layer construction and support structures, even for overhang geometries. Complex and overhang geometries, branched hierarchical structures with smooth transitions, circular cross‐sections, smooth surfaces, and micro‐scale features (as small as 50 µm) are demonstrated. As a sample application, the ice templates are used as sacrificial geometries to produce resin parts with well‐defined internal features. This approach could bring exciting opportunities for microfluidics, biomedical devices, soft electronics, and art.

Species-specific efficiency in PM2.5 removal by urban trees: From leaf measurements to improved modeling estimates

The growing population in cities is causing a deterioration of air quality due to the emission of pollutants, causing serious health impacts. Trees and urban forests can contribute through the interception and removal of air pollutants such as particulate matter (PM). The dry deposition of PM by vegetation depends on air pollutant concentration, meteorological conditions, and specific leaf traits. Several studies explored the ability of different plant species to accumulate PM on leaf structures leading to the development of models to quantify the PM removal. The i-Tree Eco is the most used model to evaluate ecosystem services provided by urban trees. However, fine particulate matter (PM2.5) removal is still calculated with a poorly evaluated function of deposition velocity (which depends on wind speed and leaf area) without differentiating between tree species. Therefore, we present an improvement of the standard model calculation introducing a leaf trait index to distinguish the species effect on PM net removal. We also compared model results with measurements of deposited leaf PM by vacuum filtration. The index includes the effect of morphological and functional leaf characteristics of tree species using four parameters: leaf water storage, deposition velocity, resuspension rate and leaf washing capacity. Leaves of 11 common urban tree species were sampled in representative areas of the city of Ferrara (Italy) and at different times of the year from 2018 to 2021. This includes four deciduous broadleaf trees (Tilia cordata, Platanus acerifolia, Acer platanoides, Celtis australis), three evergreen broadleaf trees (Quercus ilex, Magnolia grandiflora, Nerium oleander), and four conifers (Thuja orientalis, Cedrus libani, Pinus pinaster, Picea abies). The results provide significant advancement in assessing PM removal using decision support tools such as models to properly select tree species for future urban tree planting programs aimed at improving air quality.

Lithological-genetic features of Starorusskaya, Vasileostrovskaya and Siverskaya formations of the Upper Vendian-Lower Cambrian Baltic-Ladoga Monocline

Research subject. Sections of the Upper Vendian-Lower Cambrian, opened at the beginning of the XXI century by wells Avloga-12R, Utkina Zavod - 1 and Thais-2 with a depth of 150-370 m, in the north and in the central part of the Leningrad region. Methods. The analysis of the structural and textural features of the rocks of the contact layers, the distribution of allotigenic (quartz, feldspar) and autigenic (pyrite, siderite, glauconite) minerals in them allowed us to supplement the characteristics of the Old Russian, Vasileostrovsky and Siverskaya formations previously isolated in these wells. The use of the structural-genetic method made it possible to clarify the volumes and boundaries of the formations, to prove the absence in the section of the Lomonosov formation, previously isolated in the well Thais-2. Results. Based on the reconstruction of sedimentation conditions and settings, the development of sedimentation processes over time, three transgressive-regressive sequences of layers - cyclothemes were established in sections. The first corresponds to the Old Russian, the second - Vasileostrovskaya, and the third - Siverskaya formation. It is shown that in the studied part of the paleobasin at the end of the Vendian-the beginning of the Cambrian, there were open shelf environments (an area of mobile shallow water with underwater shafts (zone Y), an area of relative deep water with background and storm sedimentation (zone X) and a transitional zone of patchwork sands between X and Y with a variable hydrodynamic regime. The maxima of transgressions corresponding to the development of the deepest water environments occurred in the middle of the Old Russian, Vasileostrovsky and Siversky time, and the maxima of regressions marked by shallow water deposits belong to the end of these time intervals. According to isochronous levels - maxima of transgressions and regressions, correlation of well sections was performed.

Uranium enrichment associated with geothermal alteration: An example from Rehai, Tengchong volcanic area of China

For the continental rift‐related geothermal system, the hydrothermal alteration zones are rarely studied for uranium exploration. High uranium concentrations (up to 36 ppm) are shown in the altered sandstones at the Rehai geothermal field (RHGF) in Tengchong, China. To demonstrate the uranium enrichment mechanism, this study comparatively examines the trace element (uranium in particular) and rare earth element (REE + Y) concentrations of hot spring water, spring deposits (sinters and sulphates), and altered host sandstones from the RHGF of the Tengchong volcanic area. Along the central north‐south trending fault at Rehai, sinters and sulphates are precipitated from hot spring water, and the Neogene sandstones have been altered by hydrothermal fluids into zones formed of various clay minerals. The δD and δ18O values for the hot spring water indicate that the geothermal water originates from meteoric water. The spring water and hot spring deposits have identical REE distribution patterns which are featured with heavy REE (HREE) enrichment and negative Eu anomalies. Among the hot spring deposits, the yellowish earthy aggregates (tamarugite) deposited at the acidic Zhenzhu Spring have the maximum U concentration (27 ppm). The altered sandstones at Rehai, however, display the highest U concentrations (14–36 ppm). The U enrichment in the hot spring deposits and altered host rocks at the Rehai geothermal field is probably related to the multiple cycles of uranium leaching from granites, transportation upward along fault structures by geothermal water, decompression, and fixation in the hot spring deposits and/or alteration products. The results indicate that alteration zones associated with geothermal systems are also potential targets for uranium exploration.

Investigation of Corrosion and Scaling Potential in Drinking Water in Rafsanjan, Iran

Introduction: Corrosion and scaling are important factors affecting drinking water quality, causing health and economic problems. This study aimed to investigate the indicators of corrosion and scaling in Rafsanjan drinking water.&#x0D; Materials and Methods: The present descriptive cross-sectional study was conducted in winter 2018 and spring 2019 in Rafsanjan. The 56 samples were randomly taken from the drinking water distribution and transmission networks. Physicochemical parameters, such as pH, temperature, total dissolved solids (TDS), total hardness (TH), calcium hardness (CH), electrical conductivity (EC), and alkalinity were measured. Finally, corrosion and scaling indices, including langelier index (LI), ryznar index (RI), aggressiveness index (AI), and Puckorius index (PI) were calculated and analyzed.&#x0D; Results: The mean temperature, pH, CH, TH, TDS, alkalinity, and EC were 17.79 ± 0.80 °C, 8.08 ± 0.11, 56.34 ± 2.72 mg/L.CaCO3, 140.86 ± 6.81 mg/L.CaCO3, 530 ± 110 mg/L, 181.21 ± 13.65 mg/L, and 840 ± 180 µs/cm, respectively. The mean corrosion and scaling indices, including LI = 0.18 ± 0.12, RI = 7.72 ± 0.14, AI = 12.09 ± 0.11, and finally PI = 7.96 ± 0.10 were obtained.&#x0D; Conclusion: Based on the obtained data, drinking water in the transmission and distribution network of Rafsanjan has scaling properties. Water scaling and deposition causes problems, such as blockage of water transmission and distribution pipes, reduction of flow rate and increase of pressure drop in the network, and finally increase of water facilities operation costs. Therefore, measures should be considered to control the scaling of water in this region.