Source Of Cu Research Articles

Effects of soil properties on heavy metal bioavailability and accumulation in crop grains under different farmland use patterns

Mining activities have increased the accumulation of heavy metals in farmland soil and in food crops. To identify the key soil properties influencing heavy metal bioavailability and accumulation in food crops, 81 crop samples and 81 corresponding agricultural soil samples were collected from rape, wheat, and paddy fields. Heavy metal (copper (Cu), zinc (Zn), lead (Pb), cadmium (Cd), iron (Fe), and manganese (Mn)) concentrations in soils and rape, wheat, rice grains were determined using inductively coupled plasma atomic emission spectroscopy, and soil physicochemical properties (pH, organic matter, total nitrogen, total phosphorus, available phosphorus, and available potassium (AK)) were analyzed. Soil extractable metals were extracted using various single extractants (DTPA, EDTA, NH4OAc, NH4NO3, and HCl). The average concentrations of Cu, Zn, Pb, Cd, and Mn in the soil samples all exceeded the local geochemical background value (background values of Cu, Zn, Pb, Cd, and Mn are 43.0, 81.0, 28.5, 0.196, and 616 mg/kg, respectively), and Cd over-standard rate was the highest, at 98%. Furthermore, soil total Cd concentrations (0.1–24.8 mg/kg) of more than 86% of the samples exceeded the soil pollution risk screening value (GB 15618-2018). The sources of Cu, Zn, Pb, Cd, and Mn in soils were mainly associated with mining activities. The key factors influencing heavy metal bioavailability were associated with the types of extractants (complexing agents or neutral salt extractants) and the metals. Cd and Pb concentrations in most wheat and rice grain samples exceeded the maximum allowable Cd and Pb levels in food, respectively, and Cd concentrations in approximately 10% of the rice grain samples exceeded 1.0 mg/kg. Furthermore, rice and wheat grains exhibited higher Cd accumulation capacity than rape grains, and despite the high soil Cd concentrations in the rape fields, the rape grains were safe for consumption. High soil pH and AK restricted Cd and Cu accumulation in wheat grains, respectively. Soil properties seemed to influence heavy metal accumulation in rice grains the most.

Biogeographic patterns of benthic microbial communities in metal(loid)-contaminated semi-enclosed bay

Anthropogenic activities can adversely impact biogeochemical processes essential for maintaining ecosystem health in semi-enclosed bays. However, the influence of anthropogenic contaminants such as potentially toxic elements on microbial communities that regulate biogeochemical cycles in semi-enclosed bays is poorly understood. We determined the concentrations of four potentially toxic elements (Cu, Zn, Pb, and As) in sediments from a typical tropical semi-enclosed bay in Guangdong, China. Source apportionment using Pearson's correlation analysis revealed that aquaculture activities were probably the primary source of Cu, Zn, and Pb. Using high-throughput sediment DNA sequencing, we found that Proteobacteria was the dominant phylum in sediments. There was no evidence suggesting site-specific variation in microbial function even though sediments adjacent to aquaculture discharge points had higher microbial diversity. In contrast, pollutant-specific variations were observed; for example, Zn and Pd showed potential adverse effects on the environmental information processing function, while As showed a negative correlation with metabolic function. Based on different environmental characteristics, future research should consider the impact of multiple factors on the bacterial community in aquaculture systems.

Relations between nutrients and bioactive compounds of commercial tomato varieties by the Principal Component Analysis

This study evaluated relations among nutrients, bioactive compounds and antioxidant activity of commercial tomato varieties grown in field conditions in order to identify their biological potential by the Principal Component Analysis (PCA). Four commercial tomato varieties (Long Life, Italian, Khaki and Cherry), homogenized by their maturation stage (color, sugar/acidity ratio and pH) were evaluated regarding macro components (sugars, pectin and minerals) and functional ones (carotenoids, phenolic compounds and ascorbic acid). Cherry tomatoes stood out for their pectin and lycopene contents and their sugar/acidity ratio. Tomato samples were good sources of Cu and Ca. The PCA showed that the antioxidant potential of phenolic compounds was related to protocatecoic acid and quercetin concentrations. Italian and Cherry varieties stood out for their carotenoid contents. In field conditions, Cherry and Italian tomatoes were the best sources of functional compounds among the most common varieties found in the human diet.

Pollution Characteristics and Sources Analysis of Soil Heavy Metal in Taoyuan Coal Mine of Suzhou City

Soil is one of the most important resources and an important part of ecosystem in the development of human survival. The purposes of this study are to investigate concentration characteristics and sources analysis of heavy metals in Taoyuan coal mine of Suzhou City. 30 soil samples were collected and characterized for metal concentration (Cd, Cr, Cu, Pb, Zn and As), then the heavy metal pollution was evaluated by using pollution load index and geoaccumulation index and the sources of heavy metals were analyzed. The results revealed that the mean concentrations, except Cr, were considerably higher the reference values, especially Cd, Cu Pb and Zn in study area soil, than non-mining soil in Suzhou. The results of the geoaccumulation index (Igeo) showed the following sequence: Cd>Cu>Pb>Zn>As>Cr. At the same time, Cr and As of all samples were not contaminated, Zn and Pb were non-pollution to light pollution, Cd and Cu were light pollution to moderate pollution. The potential ecological ecological risk (Ei) values of Cd had a strong risk pollution and the other five metals belonged to a light ecological risk, the potential ecological risk (RI) mean implied moderate pollution for samples in the study area. The correlation analysis declared that the first principal component is dominated by Cd, Zn and Pb and marked correlation indicate that they should be related to coal mining, smelting processing, weathering, leaching and coal transportation. The second principal component was occupied by Cr, Cu and As, the source of Cu may be affected by Zn and Pb, Cr and As can be regarded as from the soil parent materials. It was believed that the heavy metals in the soil of Taoyuan Coal Mine were polluted to a certain extent and the accumulation of Cd, Zn and Pb were mainly affected by mining activities.

Assessing ecological risks and probable sources of Cu, Zn, and Mn in River Tana sediments, Kenya

ABSTRACT Current study aimed at finding the concentrations, ecological risks and probable sources of Cu, Zn, Mn and Fe heavy metals in River Tana surface sediments. Ecological risks were assessed using enrichment factors (EF) and potential ecological risk indices (PERI), while principal component analysis (PCA) was used to deduce the probable sources of the heavy metals. The average concentrations of Fe, Mn, Zn, and Cu (in mg/kg dry weight) were 338, 338, 4.71, and 2.23, respectively, and were below the permissible levels in sediments. The average Mn, Zn, and Cu enrichment was 63.2, 16.7, and 8.7, respectively. Based on the average EF, Mn was found to be extremely enriched while Cu and Zn enrichment was classified as significant. High Mn and Zn enrichment characterized the upper catchment areas compared to downstream. Cu was more enriched in the upper catchment and mid regions where extensive agriculture was practiced. However, the maximum recorded PERI was 4.13, therefore indicating low potential ecological risks. PCA analysis resulted to two principal components (PC). PC1 was loaded with Fe, Mn and Zn that was sourced from natural sources. PC2 contained Cu, which was sourced from anthropogenic activities including urban runoff, vehicular emissions and use of agricultural-based chemicals.

Soil Cu and Zn pools and their availability in response to forest residue management and micronutrient fertilization in a Eucalyptus grandis plantation

Eucalyptus is one of the most commonly planted genera worldwide for commercial timber purposes. Brazil has approximately 25% of the total Eucalyptus spp. planted worldwide. However, nutritional disorders caused by copper (Cu) and zinc (Zn) deficiencies have been more frequent in Eucalyptus plantations. Furthermore, the scientific knowledge regarding micronutrient fertilization is scarce. Sequential extraction can determine the distribution of metals in the soil, giving an order of magnitude to its bioavailability. The present study aimed to assess the soil Cu and Zn pools and evaluate the effects of mineral Cu and Zn fertilization on the nutritional status and nutrient fractionation in a Ferralsol in a cultivated Eucalyptus grandis plantation. The study considered two conditions—namely, forest residue management or removal of forest residues. The treatments included complete fertilization, no application of Cu, no application of Zn, maintenance of forest residues, and total removal of forest residues. High quantities of Cu and Zn were found in the soil, mainly in the low plant-available forms (>60%). There were no differences in the nutritional status of the trees, despite the absence of Cu and Zn via fertilizers and the removal of harvest residues. Foliar Cu concentration was positively correlated with soil exchangeable and oxide-bound Cu content, whereas foliar Zn concentration was positively correlated with soil exchangeable and organic matter-bound Zn content. The access to moderately labile forms of Cu and Zn by eucalypts may justify the absence of response to mineral fertilization, especially in areas where forest residues remain on the soil, and consequently, work as a source of Cu and Zn.

Distribution, source identification and environmental risk assessment of potentially toxic elements (PTEs) in the surface sediment of Sanmen Bay, Zhejiang Province, China

In this paper, the distribution, degree of pollution and sources of Cu, Pb, Zn, Cd, Cr, As, Co, Ni and Hg in the surface sediment of Sanmen Bay were studied. The average concentrations of the identified potentially toxic elements (PTEs) were in the following order: Zn > Ni > Cr > Cu > Pb > Co > As>Cd > Hg. Almost all PTEs had a significant positive correlation with TOC, clay and Al; Cr had no significant correlations. Apart from Hg, the contamination levels of 8 PTEs were at those considered to be low-to-no pollution. Comparatively, the contamination level of Hg was much higher than the background value, which indicated moderate pollution. The source of this pollution may have included industrialization, urbanization and/or transport of industrial waste materials. Both geoaccumulation index (Igeo) and potential ecological risk (RI) values suggested that Hg was the major contributor to the ecological risk posed by the selected PTEs.

Different copper sources and levels affect growth performance, copper content, carcass characteristics, intestinal microorganism and metabolism of finishing pigs.

Copper (Cu) is an essential trace element in the production of swine. This study was conducted to investigate the effect of 3 different sources of Cu on growth performance, Cu metabolism, and intestinal microorganisms of finishing pigs, so as to estimate the bioavailability of the 3 sources for pigs. A total of 42 male finishing pigs (88.74 ± 5.74 kg) were randomly allocated to 7 treatments. The factors were 3 sources (CuSO4, Cu-glycine, Cu-proteinate) and 2 levels (5 and 20 mg/kg) of Cu, plus one negative control treatment (0 mg/kg added Cu level) for the entire 28-d experiment. The average daily gain (ADG) and feed to gain ratio (F:G) both increased when Cu was added. The Cu level in liver, bile, kidney, serum, lung, urine and feces rose (P < 0.001) with increasing dietary Cu level regardless of the source. Meanwhile, pigs receiving organic Cu (glycinate or proteinate) retained more Cu and excreted less Cu than those receiving inorganic Cu (CuSO4), which showed that organic forms were more bioavailable. At the transcriptional level, changes in the level and source of dietary Cu resulted in modulation of transporters. In the jejunal mucosa, import transporter high affinity copper uptake protein 1 (CTR1) and export transporter ATPase copper transporting alpha (ATP7A) in supplemental Cu treatments were down-regulated compared to the control. Also, peptide transporter 1 (PepT1) and lanine-serine-cysteine transporter, type-2 (ASCT2) were significantly (P < 0.01) up-regulated in 20 mg/kg Cu-proteinate and Cu-glycinate treatments, respectively. Microbial diversity was lowest in the 20 mg/kg CuSO4 treatment, and the ratio of Firmicutes to Bacteroidetes was higher in added Cu treatments, especially Cu-glycinate treatment. These results indicate that uptake of different Cu forms is facilitated by different transporters and transport mechanisms, and compared with inorganic Cu, organic Cu provides benefits to intestinal microflora and reduces Cu excretion.

Metal anomalies in zircon as a record of granite-hosted mineralization

Granite-hosted magmatic-hydrothermal mineral deposits are major sources of Cu, Mo, Sn, Li, and W, originating via mineralizing fluids exsolved from volatile-saturated magmas. We show how trace elements in zircon sampled from the granite-hosted Zaaiplaats tin deposit, Bushveld Complex, preserve a record of both the enrichment of incompatible metals during magma fractionation and those arising from magmatic-hydrothermal mineralization processes. The Zaaiplaats granites are subdivided into three groups; mineralized, altered, and unmineralized. Zircon trace element contents define two trends in a plot of Sn against Gd: Sn/Gd ratios in zircons from the unmineralized samples, as well as the majority of altered samples, define a magma fractionation trend with increasing Y at constant Sn/Gd, whereas those from the mineralized samples are displaced to high Sn/Gd ratios at similar Y. Elevated Sn in the Zaaiplaats zircons is attributed to the introduction of a Sn-rich mineralizing fluid during zircon growth, which occurred at an advanced stage of crystallization (>85%) of the host magma. This model is consistent with the preservation of whole-rock Sn zonation in the Zaaiplaats granites modelled by closed-system magma differentiation and the ensuing exsolution of an acidic, saline Sn-rich magmatic-hydrothermal fluid (Groves and McCarthy, 1978). A metal anomaly, Sn/Sn*, is defined which describes the deviation of Sn over that expected through magma fractionation alone (Sn*), and arises from Sn mobilization due to magmatic-hydrothermal mineralization processes. Identification of metal anomalies such as Sn/Sn* and Cu/Cu* in mineral archives or at the whole-rock level, provides an empirical link to the onset of mineralization processes in magmatic-hydrothermal systems, and can be coupled with geochemical proxies to yield a better understanding of the conditions leading up to, and subsequent to, volatile saturation.

The Mina Justa Iron Oxide Copper-Gold (IOCG) Deposit, Peru: Constraints on Metal and Ore Fluid Sources

Abstract Iron oxide copper-gold (IOCG) deposits are major sources of Cu, contain abundant Fe oxides, and may contain Au, Ag, Co, rare earth elements (REEs), U, and other metals as economically important byproducts in some deposits. They form by hydrothermal processes, but the source of the metals and ore fluid(s) is still debated. We investigated the geochemistry of magnetite from the hydrothermal unit and manto orebodies at the Mina Justa IOCG deposit in Peru to assess the source of the iron oxides and their relationship with the economic Cu mineralization. We identified three types of magnetite: magnetite with inclusions (type I) is only found in the manto, is the richest in trace elements, and crystallized between 459° and 707°C; type Dark (D) has no visible inclusions and formed at around 543°C; and type Bright (B) has no inclusions, has the highest Fe content, and formed at around 443°C. Temperatures were estimated using the Mg content in magnetite. Magnetite samples from Mina Justa yielded an average δ56Fe ± 2σ value of 0.28 ± 0.05‰ (n = 9), an average δ18O ± 2σ value of 2.19 ± 0.45‰ (n = 9), and Δ’17O values that range between –0.075 and –0.047‰. Sulfide separates yielded δ65Cu values that range from –0.32 to –0.09‰. The trace element compositions and textures of magnetite, along with temperature estimations for magnetite crystallization, are consistent with the manto magnetite belonging to an iron oxide-apatite (IOA) style mineralization that was overprinted by a younger, structurally controlled IOCG event that formed the hydrothermal unit orebody. Altogether, the stable isotopic data fingerprint a magmatic-hydrothermal source for the ore fluids carrying the Fe and Cu at Mina Justa and preclude significant input from meteoric water and basinal brines.

PSXIII-16 Supplementing organic-complexed or inorganic Co, Cu, Mn, and Zn to beef cows during gestation: physiological and productive responses of cows and their offspring until weaning

Abstract Pregnant, non-lactating beef cows (n = 190; 117 ± 2.2 d of gestation; d 0) were assigned to receive: 1) sulfate sources of Cu, Co, Mn, and Zn (INR; n = 95) or 2) an organic complexed source of Cu, Mn, Co, and Zn (AAC; Availa®4, Zinpro; n = 95). From d 0 to calving, cows were maintained in a single pasture and individually offered treatments three times weekly. Cow BW and BCS were recorded on d -30, d 97, upon calving, and at weaning and liver biopsies performed in 30 cows/treatment. Milk production was estimated at 42 ± 0.5 d postpartum via weigh-suckle-weigh (WSW). Liver and longissimus muscle (LM) biopsies were performed in 30 calves/treatment upon calving and 24 h later, at WSW, and at weaning. No treatment effects were detected (P ≥ 0.49) for cow BCS, despite AAC cows having greater (P = 0.04) BW on d 97. Liver Co (P &amp;lt; 0.01) concentrations were greater for AAC compared to INR cows, and liver concentrations of Cu were greater (P = 0.02) for INR compared to AAC cows on d 97. Upon calving, INR cows had greater (P ≤ 0.01) liver Cu and Zn concentrations compared to AAC cows. Cows receiving AAC had greater (P = 0.04) hepatic mRNA expression of metallothionein 1A at calving, and their calves had greater (P = 0.04) hepatic mRNA expression of superoxide dismutase at weaning. Milk production did not differ between AAC and INR cows (P = 0.70). No treatment effects were detected (P ≥ 0.29) for mRNA expression of LM genes in calves at birth and weaning. Calf birth and weaning BW were similar (P ≥ 0.19) between treatments. Hence, supplementing AAC or INR to beef cows during the last 5 mo of gestation yielded similar cow-calf productive responses until weaning.

PSXIII-17 Supplementing organic-complexed or inorganic Co, Cu, Mn, and Zn to beef cows during gestation: post-weaning responses of offspring reared as replacement heifers or feeder cattle

Abstract Beef cows and their progeny were used to evaluate the effects of supplementing organic-complexed or inorganic Co, Cu, Mn, and Zn during gestation: on offspring reared as replacement heifers or feeder cattle. Non-lactating, pregnant beef cows (n = 190) were ranked by parity, pregnancy type, body weight (BW) and body condition score (BCS), at 117 ± 2.2 d of gestation (d 0) and assigned to receive a supplement containing: 1) sulfate sources of Cu, Co, Mn, and Zn (INR; n = 95) or 2) an organic complexed source of Cu, Mn, Co, and Zn (AAC; Availa®4; Zinpro Corporation, Eden Prairie, MN; n = 95). From d 0 to calving, cows were maintained in a single pasture and individually offered treatments three times a week. Calves were weaned at 6 mo of age (d 367) and preconditioned for 45-d. Heifer puberty status was verified weekly (d 437 to d 619) based on plasma progesterone concentrations. Steer calves were shipped to a commercial feedlot on d 493, where they were managed as a single group until slaughter (d 724). Plasma cortisol concentration was greater (P = 0.05) in AAC calves at weaning but tended to be less (P = 0.10) on d 370 compared with INR calves. Mean plasma haptoglobin concentration was greater (P = 0.03) in INR vs. AAC calves during preconditioning, and no treatment effects were noted (P = 0.76) for preconditioning average daily gain (ADG). Puberty attainment was hastened in AAC heifers during the experiment (treatment × day; P &amp;lt; 0.01), despite similar (P = 0.39) ADG between treatments from d 412 to 620. No treatment effects were detected (P ≥ 0.24) for steer ADG from d 412 until slaughter, nor for carcass quality traits. Therefore, supplementing Co, Cu, Zn, and Mn as organic complexed instead of sulfate sources to beef cows during the last 5 mo of gestation did not improve performance of steer progeny until slaughter, but hastened puberty attainment in female progeny reared as replacement heifers.

101 Awardee Talk: Impacts of Gestational and Early-life Nutrition on Productive Responses of Beef Cattle

Abstract Nutritional management during gestation as well as postnatally is critical to optimize efficiency and profitability of beef cattle systems. Two experiments were performed evaluating the effects of trace mineral supplementation during gestation and supplementation with calcium salts of soybean oil (CSSO) to nursing beef steers on performance and physiological responses. In experiment one, the impact of inorganic or organic Co, Cu, Mn, and Zn supplementation to beef cows during gestation were evaluated on parameters associated with offspring performance and physiological responses. One hundred and ninety non lactating pregnant beef cows were assigned to the experiment at 117 ± 2.2 days of gestation (d 0) and received diets containing either 1) sulfate sources of Cu, Co, Mn, and Zn (INR), or 2) organic complexed source of Cu, Co, Mn, and Zn (AAC). No treatment differences were detected (P ≥ 0.19) for calf body weight at birth or at weaning. Heifers born to INR cows had delayed puberty attainment (treatment ×day interaction; P &amp;lt; 0.01), whereas no treatment differences were detected (P ≥ 0.24) for carcass traits when male offspring were reared as feeder cattle. In experiment two, the impacts of supplementing CSSO at 2 months of age via creep-feeding and/or postweaning via preconditioning were evaluated on parameters associated carcass quality and development. Steers receiving CSSO at 2 mo of age had greater (P ≤ 0.01) mRNA expression of genes associated with lipid metabolism in the longissimus muscle later in life, although no treatment differences were detected for performance or carcass traits (P ≥ 0.18). Outcomes of these experiments may be used to develop nutritional strategies to enhance productive efficiency in beef cattle systems. Research is still warranted to examine the effects of such supplementation during these periods of developmental plasticity on cattle productivity.

PSVII-16 Effects of different forms of Cu on in vitro ruminal fermentation and digestibility of a lactation diet

Abstract Vistore® mineral products are hydroxychloride minerals that feature high metal content and improved bioavailability. This study was conducted to compare different sources of copper (Cu) on in vitro rumen fermentation parameters. Three ruminally-cannulated Jersey heifers were adapted to a lactation diet for two weeks before being used as donors. Three sources of Cu at 4 ppm: No supplemental Cu (CON), CuSO4, Vistore Cu, and another Cy hydroxychloride product (Vistore-competitor). The concentration of Cu in this study was selected from a titration study (0 to 8 ppm CuSO4) to identify the minimum concentration of CuSO4 affecting rumen fermentation. The lactation diet (TMR) was dried and ground to 1mm and used as the substrate. Rumen fluid was collected two hours after feeding. Substrate (0.5 g) was inoculated with 100 mL of a 3:1 McDougall’s buffer: ruminal fluid mixture at 39ºC for 24 h. Each treatment was run in triplicate and in three runs. Data were analyzed with R 4.0. The model included fixed effect of treatment and random effect of run. CuSO4 tended to increase lag time (0.78 vs -0.57 h, P = 0.06), reduced (P &amp;lt; 0.05) DMD (52.4 vs. 56.1%), cellulose digestibility (4.9% vs. 41.9%), isobutyrate molar % (0.58 vs. 0.78%) and NH3-N concentration (5.46 vs. 6.91 mg/dL). Vistore and Vistore-competitor maintained the fermentation and digestibility compared to CON. In general, Vistore Cu and Vistore-competitor maintained ruminal fermentation and digestibility parameters while negative effects of CuSO4 were observed. These results indicate different Cu mineral sources may affect the rumen differently.

Porphyry CU deposits in the Central Andes of Argentina: An overview

Porphyry Cu deposits are the world's most important source of Cu and the Central Andes of South America hold some of the largest Cu resources worldwide. In Argentina many porphyry-type deposits and prospects with different degrees of exploration straddle along ~1500 km of the Central Andes. The review and analysis of the tectono-magmatic, metallogenic and economic data of the better-known deposits and prospects allow to define the controls of porphyry-type mineralization and the metallogenic epochs and belts which in turn indicate the potential for porphyry-type mineralization in some relatively poorly explored segments of the Central Andes.Slab shallowing (particularly linked to the subduction of aseismic ridges) and associated eastward arc migration/expansion appears to be a favorable geodynamic scenario for Paleozoic and Cenozoic mineralizing magmatism which show variable adakitic signatures probably as a result of a progressive crustal thickening. In this context the V/Sc and especially the Sr/Y ratios are a useful tools for assessing magma fertility. Major WNW-trending deep crustal pre-Andean structures controlled the inland migration of the magmatism and are a first order control on porphyry emplacement during these epochs of magmatic activity.There are five favorable metallogenic epochs linked to the arc magmatism in Argentina: Permian, Upper Cretaceous-Eocene, late Eocene-early Oligocene, late Oligocene-early Miocene and Miocene-Pliocene. The Permian and Upper Cretaceous-Eocene metallogenic epochs are represented by a small number of deposits with low metal (Cu–Mo–Au) content; however, the extension of the magmatism of both epochs suggests they are favorable for further exploration. The late Eocene–early Oligocene magmatism involves few deposits but formed the second largest known copper resource in Argentina. The Miocene-Pliocene magmatism, particularly between ~11 and 6 Ma, generated the largest porphyry-type deposits with the greatest metal resources. Based on the available information ten metallogenic belts are outlined: 1) Permian Puna-Frontal Cordillera/Neuquén basement, 2) Upper Cretaceous–Eocene Neuquén, 3) late Eocene-early Oligocene, 4) late Oligocene-early Miocene, 5) middle Miocene Puna-Frontal Cordillera, 6) middle Miocene Precordillera, 7) late Miocene Cordillera, 8) late Miocene-Pliocene Cordillera, 9) late Miocene-Pliocene Northern Sierras Pampeanas, 10) late Miocene-Pliocene Famatina. These ten metallogenic belts accumulate 74.21 Mt Cu, 1.70 Mt Mo, 2160.66 t Au and 23,876.71 t Ag of known resources and approximately 239 Mt Cu, 6.4 Mt Mo, 4240 t Au and 77,900 t Ag contained in undiscovered deposits. The Miocene belts are the most endowed, confirming their economic importance as well as their prospectivity for exploration. The largest total known resources are hosted by the late Miocene belt in the Frontal Cordillera, followed by the late Eocene-Early Oligocene one and the Miocene-Pliocene belt in the Sierras Pampeanas. The continuation of the late Miocene-Pliocene Cordillera belt that extends from Los Bronces and El Teniente in Chile, further south into Argentina, is here considered the most prospective underexplored belt.

Cu(I)-based molecular emitters for quantification of fluoride and phosphate in surface waters

Advances in material science, optics, and electronics allow the creation of simple and low-cost measuring devices for various applications. In the present work, an optical multisensor system was designed using Cu(I) molecular emitters as a light source. The major advantage of this measuring platform is the ability to adjust the source wavelength for a particular analytical task. Here the possibility to measure fluoride and phosphate content in natural and tap waters using the optical setup with a UV flashlight as an excitation source for Cu(I) complexes has been demonstrated. The root mean-square prediction error (RMSEP) value for analyzed water samples attained with partial least-squares (PLS) regression method was 0.07 mg/L for both fluoride (0–0.4 mg/L concentration range) and phosphate (0–0.96 mg/L). These values are comparable with those for standard analytical techniques. This proof of concept study confirms the possibility of constructing adjustable optical multisensor systems based on Cu(I) emitters for real-life applications.

Pollutant source, ecological and human health risks assessment of heavy metals in soils from coal mining areas in Xinjiang, China

This study aims to analyze the pollution characteristics and sources of heavy metal elements for the first time in the Zhundong mining area in Xinjiang using the linear regression model. Additionaly, the health risks with their probability and infleuencing factors on different groups of people's were also evaluated using Monte Carlo (MC) simulation approach. The results shows that 89.28% of Hg was from coal combustion, 40.28% of Pb was from transportation, and 19.54% of As was from atmospheric dust. The main source of Cu and Cr was coal dust, Hg has the greatest impact on potential ecological risks. which accounted for 60.2% and 81.46% of the Cu and Cr content in soil, respectively. The all samples taken from Pb have been Extremely polluted (100%). 93.3% samples taken from As have been Extremely polluted. The overall potential ecological risk was moderate. Adults experienced higher non-carcinogenic risks of heavy metals from their diets than children. Interestingly, body weight was the main factor affecting the adult's health risks. This research provides more comprehensive information for better soil management, soil remediation, and soil pollution control in the Xinjiang mining areas.

Spatio-temporal Distribution Characteristic and Risk Assessment of Heavy Metals in Soils Around Centralized Drinking Water Sources in Wuhan

In the present study, the spatio-temporal distribution characteristics of heavy metals (Cd, Hg, As, Pb, Cr, Cu, Ni, and Zn) in soil around 19 centralized drinking water sources in Wuhan were investigated. Single-factor and comprehensive pollution indexes were used to determine soil pollution levels. The potential ecological hazard index was employed to evaluate soil potential ecological risks. The correlation and cluster analysis were conducted to identify pollution sources. The results showed that higher concentrations of heavy metals were present in soil from centralized drinking water source located in core area than suburb area of Wuhan. The concentrations of heavy metals in soil from centralized drinking water sources near the Yangtze River were higher than that in the sites near the tributaries of the Yangtze River. The average single potential ecological risk index of Hg, As, Pb, Cr, Cu, Ni, and Zn were lower than 40, which suggests a slight potential ecological risk. The average single potential ecological risk index of Cd was 80-160, which indicates a high potential ecological risk. The average comprehensive potential ecological risk index of heavy metals in soil around centralized drinking water sources in Wuhan was 142.12, which corresponded to a slight potential ecological risk. The correlation analysis showed that the sources of Cu, Pb, and Cr were similar and came from transport. The sources of Ni, As, Cr, and Cu were similar and could be attributed to metallurgical industries. The sources of Zn, Hg, and Cr were similar and could be related to antiseptic and catalytic industries. The long-term monitoring of Wuhan Dijiao and Baishazhou waterworks indicated that the concentrations of heavy metals around centralized drinking water sources in Wuhan were markedly decreased after 2017 and that ecological risk may be further reduced in the future.

The Relation between Trace Element Composition of Cu-(Fe) Sulfides and Hydrothermal Alteration in a Porphyry Copper Deposit: Insights from the Chuquicamata Underground Mine, Chile

Porphyry Cu-Mo deposits are among the world’s largest source of Cu, Mo, and Re, and are also an important source of other trace elements, such as Au and Ag. Despite the fact that chalcopyrite, bornite, and pyrite are the most common sulfides in this deposit type, their trace element content remains poorly constrained. In particular, little is known about minor and trace elements partitioning into Cu-(Fe) sulfides as a function of temperature and pH of the hydrothermal fluid. In this study, we report a comprehensive geochemical database of chalcopyrite, bornite, and pyrite in the super-giant Chuquicamata porphyry Cu-Mo deposit in northern Chile. The aim of our study, focused on the new Chuquicamata Underground mine, was to evaluate the trace element composition of each sulfide from the different hydrothermal alteration assemblages in the deposit. Our approach combines the electron microprobe analysis (EMPA) and laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) of sulfide minerals obtained from six representative drill cores that crosscut the chloritic (propylitic), background potassic, intense potassic, and quartz-sericite (phyllic) alteration zones. Microanalytical results show that chalcopyrite, bornite, and pyrite contain several trace elements, and the concentration varies significantly between hydrothermal alteration assemblages. Chalcopyrite, for example, is a host of Se (≤22,000 ppm), Pb (≤83.00 ppm), Sn (≤68.20 ppm), Ag (≤45.1 ppm), Bi (≤25.9 ppm), and In (≤22.8 ppm). Higher concentrations of Se, In, Pb, and Sn in chalcopyrite are related to the high temperature background potassic alteration, whereas lower concentrations of these elements are associated with the lower temperature alteration types: quartz-sericite and chloritic. Bornite, on the other hand, is only observed in the intense and background potassic alteration zones and is a significant host of Ag (≤752 ppm) and Bi (≤2960 ppm). Higher concentrations of Ag and Sn in bornite are associated with the intense potassic alteration, whereas lower concentrations of those two elements are observed in the background potassic alteration. Among all of the sulfide minerals analyzed, pyrite is the most significant host of trace elements, with significant concentrations of Co (≤1530 ppm), Ni (≤960 ppm), Cu (≤9700 ppm), and Ag (≤450 ppm). Co, Ni, Ag, and Cu concentration in pyrite vary with alteration: higher Ag and Cu concentrations are related to the high temperature background potassic alteration. The highest Co contents are associated with lower temperature alteration types (e.g., chloritic). These data indicate that the trace element concentration of chalcopyrite, bornite, and pyrite changed as a function of hydrothermal alteration is controlled by several factors, including temperature, pH, fO2, fS2, and the presence of co-crystallizing phases. Overall, our results provide new information on how trace element partitioning into sulfides relates to the main hydrothermal and mineralization events controlling the elemental budget at Chuquicamata. In particular, our data show that elemental ratios in chalcopyrite (e.g., Se/In) and, most importantly, pyrite (e.g., Ag/Co and Co/Cu) bear the potential for vectoring towards porphyry mineralization and higher Cu resources.

Distribution, sources and ecological risk assessment of metals in Kura river sediments along a human disturbance gradient

Monitoring the pollution status of freshwater resources is an important step in sustainable planning. This study aimed to determine the distribution and sources of metals in the sediments of the transboundary eastern Anatolian/Caucasus region Kura river as well as its ecological risk level. Surface sediment samples were collected from eight sites along the human disturbance gradient. Multi-element analyses of the collected samples were performed using Inductively Coupled Plasma Mass Spectrometry (ICP-MS). Chlorophyll degradation product (CDP) analysis was performed spectrophotometrically. OC analysis was carried out using the titration method. The data obtained were evaluated using the indices of enrichment factor, geo-accumulation, modified hazard quotient and ecological contamination index and potential ecological risk. The average content of metals in the sediment at the eight sites was of the following descending order from highest to lowest: Al > Mn > Zn > V> Ni > Cr > Cu > Co > Pb > As > Cd > Tl > Hg. According to the distribution of raw metal values, urbanization is not the only factor controlling metal distribution. Adsorption processes and organic material content also emerge as an important factor. Enrichment factor values were of the following order: T1 > Pb > Mn > Hg > Cr > Co > Cd > Ni > As > Zn > Al > Cu > V. Results revealed that the sources of Cu, V and Al were lithogenic, in contrast to Tl, Pb, Mn, Hg, Cr, Co, Cd, Ni, and As, thus pointing to human-induced accumulation. According to the potential ecological risk index, these elements have the potential to create medium-to-high level ecological risks and were substantially of atmospheric origin. The ecological contamination index is also consistent with these findings in terms of risk level. A municipal waste stream, fossil fuel burning and a cement plant operating in close proximity also appeared to be the possible sources.