Leaching Rate Of Copper Research Articles

Leaching Thermodynamics of Low-Grade Copper Oxide Ore from [(NH4)2SO4]-NH3-H2O Solution.

This paper describes a highly alkaline low-grade copper oxide ore. Copper can be selectively leached out while other metals are retained. A thermodynamic model of the CuO-(NH4)2SO4-NH3-H2O system was established for the leaching of tenorite (CuO) under conditions of mass and charge conservation. MATLAB's fitting functions, along with the diff and solve functions, were used to calculate the optimal ammonia concentration and total copper ion concentration of tenorite under different ammonium sulfate concentrations. The effects of various ammonia-ammonium salt solutions (ammonium sulfate, ammonium carbonate, ammonium chloride) on the copper leaching rate were investigated. Results show that under the conditions of an ammonia concentration of 1.2 mol/L, an ammonia-ammonium ratio of 2:1, a liquid-solid ratio of 3:1, a temperature of 25 °C, and a leaching time of 4 h, the copper leaching rate from the ammonium sulfate and ammonium chloride solutions reaches 70%, which is slightly higher than that of ammonium carbonate. Therefore, an ammonia-ammonium sulfate system is selected for leaching low-grade copper oxide due to its lower corrosion to equipment compared to the chlorination system. The impact of this study on industrial applications includes the potential to find more sustainable and cost-effective methods for resource recovery. The industry can reduce its dependence on resources and mitigate its environmental impact. Readers engaged in low-grade oxidized copper research will benefit from this study.

Sustainable strategies for recovering metallic copper from waste printed circuit boards: Clean leaching and micro-nano copper powder preparation

Recovery and utilization of valuable metals from waste printed circuit boards (WPCBs) have the dual significance of alleviating resource shortages and protecting the ecological environment. This study focuses on the feasibility analysis of copper in WPCBs for preparing micro-nano copper powders by clean leaching and chemical reduction processes. Firstly, the effect of temperature and other parameters on copper leaching rate in glycine-hydrogen peroxide (Gly-H2O2), ammonia-ammonium chloride (NH3·H2O-NH4Cl) leaching systems with sulfuric acid-hydrogen peroxide (H2SO4-H2O2) system as control group were emphasized. Subsequently, the leaching characteristics of copper concentrate particles were analyzed by leaching kinetics to elucidate the leaching mechanism and apparent activation energy of copper. Finally, the micro-nano copper powders were prepared using ascorbic acid and sodium borohydride reduction system with different copper leach solutions as precursors. The micro-nano copper morphology and phase compositions were analyzed by SEM and XRD. The results show that both the Gly-H2O2 and NH3·H2O-NH4Cl system can replace the H2SO4-H2O2 system to achieve efficient leaching of copper. Increasing temperature can significantly enhance the copper leaching rate. When the temperature was increased from 15 °C to 45 °C, the maximum copper leaching rate in the three systems increased from 58.13 %,71.26 %,78.26 % to 90.36 %,91.21 %,92.87 %, at − 0.074 mm for 40 min. The Avrami model accurately describes the leaching behavior of copper concentrate particles, and the copper leaching process is dominated by chemical reaction control. SEM and XRD results show that micro-nano copper particles of hundreds of nanometers are successfully prepared by both reduction systems.

Cadmium, zinc, and copper leaching rates determined in large monolith lysimeters

Soil mass balances are used to assess the risk of trace metals that are inadvertently applied with fertilizers into agroecosystems. The accuracy of such balances is limited by leaching rates, as they are difficult to measure. Here, we used monolith lysimeters to precisely determine Cd, Cu, and Zn leaching rates in 2021 and 2022. The large lysimeters (n = 12, 1 m diameter, 1.35 m depth) included one soil type (cambisol, weakly acidic) and distinct cropping systems with three experimental replicates. Stable isotope tracers were applied to determine the direct transfer of these trace metals from the soil surface into the seepage water. The annual leaching rates ranged from 0.04 to 0.30 for Cd, 2.65 to 11.7 for Cu, and 7.27 to 39.0 g (ha a)−1 for Zn. These leaching rates were up to four times higher in the year with several heavy rain periods compared to the dry year. Monthly resolved data revealed that distinct climatic conditions in combination with crop development have a strong impact on trace metal leaching rates. In contrast, fertilization strategy (e.g., conventional vs. organic) had a minor effect on leaching rates. Trace metal leaching rates were up to 10 times smaller than fertilizer inputs and had therefore a minor impact on soil mass balances. This was further confirmed with isotope source tracing that showed that only small fractions of Cd, Cu, and Zn were directly transferred from the soil surface to the leached seepage water within two years (< 0.07 %). A comparison with models that predict Cd leaching rates in the EU suggests that the models overestimate the Cd soil output with seepage water. Hence, monolith lysimeters can help to refine leaching models and thereby also soil mass balances that are used to assess the risk of trace metals inputs with fertilizers.

Enhanced leaching of copper from refractory oxidized copper ore by calcium fluoride: Behavior and mechanism

The Luanshya area of Zambia is rich in copper oxide resources. However, copper mainly exists in biotite and phlogopite, which presents challenges for efficient extraction. To improve the leaching rate of copper from these ores, local hydrometallurgical plants use heating and stirring; however, the leaching rate is not high. To address the issue in this work, CaF2 was introduced as a leaching aid, and the effects of various parameters on leaching were systematically studied. The results revealed that when the dosage of CaF2 is 5wt% of raw ore mass, the dosage of sulfuric acid is 120 kg/t, the leaching temperature is 60 °C, and the leaching time is 200 min with a slurry concentration of 30wt%, the leaching rate of copper can reach 80.44%. Compared with regular heating stirring acid leaching, the copper leaching rate was found to increase by 8.76%, while the leaching temperature decreased by 5 °C and the leaching time shortened by 40 min. The results of the HSC Chemistry 6.0 thermodynamic calculations and mechanism analysis indicated that F can promote the fracture of Si–O and Al–O bonds in the crystal structure of biotite and phlogopite in sulfuric acid solution, enabling a direct reaction between the acid and copper. The proposed method can be applied not only to the treatment of cupriferous mica ores but also to the processing of other copper ores. This process is more efficient and cost-effective than the regular heating–stirring acid leaching process.

Chalcopyrite Leaching in the Presence of Isopropanol-The Kinetic and Mechanistic Studies.

Oxidative leaching, as a basic step of the hydrometallurgical process of pure copper production from chalcopyrite, is a slow process in which mineral acids with strong oxidants addition are usually used as a leaching medium. It was found experimentally that the copper leaching from chalcopyrite in the H2SO4-H2O2-H2O system, in the presence of isopropanol (IPA) and under other conditions (H2O2 concentration, rate of mixing and temperature), takes place with satisfactory rate and efficiency. To quantify how much the change of these crucial variables affects the rate of the process, experimentally obtained kinetic curves (conversion over time) were analyzed using a Shrinking Core Model (SCM). The determined values of the copper leaching rate constants (kobs) confirmed the positive influence of increasing IPA and H2O2 concentrations as well as the temperature on the kinetics and efficiency of the leaching. The kinetic studies were also supported by using X-ray diffraction (XRD), 57Fe Mössbauer spectroscopy, scanning electron microscopy (SEM), and adsorption measurements. The positive influence of IPA was explained by its stabilizing role for iron compounds (hematite, magnetite, and pyrite), which are catalysts during the Cu dissolution, as well as H2O2 protection from decomposition during free radical reactions. Finally, the optimal conditions for efficient leaching, the rate-limiting step as well as the mechanism suggestion of the copper dissolution, were given.

Mechanism and kinetics study on waste acid leaching from copper smelting dust

AbstractCopper smelters generate large amounts of copper smelting dust (CSD) that has a high recycling value because it contains about 20% copper. Waste acid can be used to leach CSD. Here, the effects of different temperatures, times and liquid–solid ratios on copper, iron and arsenic leaching rates were investigated. The optimal conditions were determined to be a temperature of 95°C, leaching time of 3 h, and liquid–solid ratio of 7:1. Under these condition, the leaching rate of copper reached 96.37%, and the copper ion concentration was 32.71 g/L. The leaching kinetics date revealed that the leaching of copper and iron was controlled by two different reaction models. The leaching of copper conformed to the Johnson–Mehl–Avrami (JMA) model and was diffusion controlled, and the reaction was rapid in the first 60 min. In contrast, leaching of iron was controlled by a chemical reaction. Copper and iron activation energies were 2.579 and 62.791 kJ/mol, respectively. These results show that CSD waste acid is can be used to dispose of arsenic‐containing hazardous waste in a green, sustainable, and ecologically method.

Study on the hydrogen production promotion effect and immobilization mechanisms of copper during the pyrolysis process of waste cotton textiles

Landfilling waste textiles causes a waste of resources. Copper is the main metal in waste textiles, and it is one of the widely used pyrolysis catalysts. This research investigated the role of copper during the pyrolysis process of waste cotton textiles, including the promoting effect on hydrogen generation and its immobilization in biochar. The pyrolysis experiment was conducted on waste pure cotton textiles impregnated with different concentrations of copper nitrate solutions. The experimental results showed that the addition of copper increased the hydrogen concentration by 121%, while the pyrolysis process reduced the copper leaching rate by 57.5%. Hydrogen concentration increased by 123% as the temperature increased, but the high temperature would affect the immobilization of copper. Hydrogen production and copper immobilization could be improved simultaneously around 700 ℃. The gas evolution was monitored by TG-MS and the biochar was characterized by XRD, FTIR, and XPS. The results indicated that the complexation of oxygen−containing functional groups and the generation of metallic copper decreased the leaching of copper, the heterostructure of copper on the surface of biochar catalyzed the secondary cleavage of organic fraction, increasing the production of hydrogen. The mechanism of hydrogen generation involved the decomposition of cellulose, the cleavage of organic macromolecules, and the secondary reaction of small molecule gases.

Experimental Study on the Influence of Surfactants on Ore Surface Wettability.

To reveal the evolution law of ore surface wettability under the condition of adding surfactant and chemical reaction, the test experiments of ore surface morphology, roughness, and chemical element distribution were carried out. The results show that the contour of the ore surface morphology was relatively flat in the early stage of leaching and the roughness factor increased slowly, while the contour fluctuated significantly in the late stage of leaching and the roughness factor increased sharply. With the leaching reaction, the roughness factor and spreading coefficient of the ore with a 0.008 mol/L surfactant (sodium dodecyl sulfate) concentration were always higher than those without surfactant and the surfactant enhanced the erosion effect of the solution on the ore surface. During the leaching process, the chemical elements Cu, Al, and K were dissolved on the ore surface, and the content of Cu decreased significantly from 2.01 to 0.86%; the leaching rate of copper was about 57.2%. According to the morphology characteristics of the ore surface during leaching and the distribution law of chemical elements on the ore surface before and after leaching, the leaching process was divided into four stages of "contact-penetration-reaction-disintegration". The surfactant had the most obvious effect on the ore surface morphology in the two stages of "reaction" and "disintegration".

A new process of selective separation and extraction of copper and germanium during zinc hydrometallurgy

ABSTRACT In view of the poor enrichment of copper and germanium and low recovery of copper during traditional zinc hydrometallurgy, this study develops a new process of acid leaching. The behaviours of zinc, iron, copper and germanium were studied under different conditions. The results showed that the final pH had significant impacts on the behaviour of metals during the leaching process. Under conditions of final pH 3.5–4.0, time 2.0 h, temperature 80°C and no oxidant, the copper leaching rate was 45.88% using weak acid leaching and the precipitation rates were 9.09% and 84.31% for germanium and iron, respectively. The next stage of low acid leaching under conditions including final pH 0.1–0.2, time 2.0 h and temperature 80°C, the total leaching rates were 92.66% and 65.64% for zinc and copper, respectively. The weak acid leachate was then subjected to copper reductive precipitation and neutralisation. The process showed that the Cu grade was 20.12% in the residue. The Cu, Fe and Ge precipitation rates were respectively 83.74%, 99.98% and 91.02% during the neutralisation, which was beneficial to the subsequent treatment. The proposed process provides high separation efficiency of copper and germanium and a high leaching rate of zinc and copper.

Dissolution and Passivation Mechanism of Chalcopyrite during Pressurized Water Leaching

In this study, chemical leaching, XRD, SEM, and XPS analyses were conducted to investigate the dissolution and passivation mechanisms of chalcopyrite under pressurized oxidative conditions in water. The chemical leaching results showed that the chalcopyrite could be dissolved by pressurized leaching without any acid addition, i.e., in an O2–H2O system, and the copper leaching rate reached 96.4% under the optimal conditions of 180 °C, 1.5 MPa, 900 rpm, and 90 min. The XRD, SEM, and XPS data suggested that a large proportion of the chalcopyrite dissolved in solution via the mineral phase transformation of CuFeS2→Cu2+ and CuFeS2→CuS→Cu2+, i.e., some of the chalcopyrite directly leached into solution as Cu2+, and some of it was first converted to CuS and then to Cu2+. The primary passivation layers during the chalcopyrite pressurized water leaching were hematite, pyrite, and covellite; however, none of them covered the un-leached mineral surface or inhibited chalcopyrite dissolution, as long as the agitation speed and leaching time were maintained over 700 rpm and 60 min, respectively. Finally, a model of chalcopyrite’s dissolution and passivation mechanism during pressurized water leaching was proposed.

Clean recovery of copper from waste printed circuit boards using ceric ammonium nitrate

A clean approach was proposed to recycle copper from waste printed circuit boards (WPCBs), which involved leaching, purification, and electrolysis. Ceric ammonium nitrate (CAN) was used as the leaching agent to dissolve copper from WPCBs, due to its strong oxidizing property and recyclability through electrolytic oxidation. The results showed that the copper leaching rate was 99.9 % under the optimized conditions.The leaching process of copper was in accordance with the mixed control model, and the apparent activation energy was 47.56 kJ/mol. After the leaching, the solution was purified to remove Ag and Sn by activated carbon, and the removal behaviors of Ag and Sn followed the pseudo-second-order model. Using the purified solution as the electrolyte to conduct the diaphragm electrolysis, copper with a purity of 99.998 % was produced at the cathode, and Ce3+ ions were simultaneously oxidized into Ce4+ ions at the anode. By using this process, copper was recycled from WPCBs, and CAN was regenerated.

Surface oxidation using chlorine dioxide for cuprite and its oxidation leaching mechanism in sulfuric acid solution

Cuprite (Cu2O) is difficult to directly leach in acidic solutions. In the absence of oxygen, the acidic leaching process of cuprite occurs via a disproportionation reaction and can achieve a maximum cuprite leaching rate of only 50%. Furthermore, to improve the copper leaching rate, Cu(Ι) in cuprite must be oxidized via electrochemical reactions. In this study, chlorine dioxide (ClO2), a novel environmentally-friendly oxidant, was used to oxidize cuprite to enhance the leaching effect in sulfuric acid (H2SO4)solution. Leaching experiments, electrochemical measurements, atomic force microscopy (AFM), scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM-EDS), X-ray photoelectron spectroscopy (XPS), and time-of-flight secondary ion mass spectrometry (ToF-SIMS) were used to analyze the oxidation leaching mechanism of cuprite under different reaction conditions. Under the condition of a leaching temperature of 50 °C, sulfuric acid concentration of 0.14 mol/L, average particle size of 60 μm, stirring speed of 800 rpm, and leaching time of 30 min, the leaching rate of cuprite reached 90.18% after adding 0.07 mol/L of ClO2. Electrochemical measurements demonstrated that a higher ClO2 concentration increased the corrosion rate of cuprite and oxidation efficiency. Moreover, the surface characterization results showed that with the addition of ClO2, monovalent copper on the cuprite surface was oxidized to divalent copper, which promoted the acidic leaching process of cuprite. In addition, once the cuprite surface was oxidized during oxidation leaching, sulfuric acid leached this layer until the end of the leaching process. The DFT calculation results further proved that with the participation of ClO2, the leaching reaction of cuprite in an acidic solution was more likely to occur. This oxidation leaching method might provide a reference for the effective leaching of cuprite.

Evaluating glycine as an alternative lixiviant for copper recovery from waste printed circuit boards

Current hydrometallurgical processing routes for copper recovery from waste printed circuit boards (PCBs) utilise strong mineral acids, which pose environmental hazards. Glycine has been proposed as an alternate lixiviant with a lower environmental impact. This study aimed to investigate the effectiveness of glycine as lixiviant for copper dissolution from waste PCBs. Bench scale laboratory leaching tests were performed to investigate the effect of key process variables such as temperature, oxidant type and lixiviant concentration on the rate, extent and selectivity of copper leaching.In the presence of oxygen as oxidant, the glycine concentration did not have a significant effect on the rate or extent of copper leaching in the range 1 M to 2 M. Increasing the temperature from 25 °C to 60 °C increased copper dissolution after 22 h from 29.6% to 81.2% when using a glycine concentration of 1 M. When air instead of oxygen was used as oxidant, the copper dissolution achieved with 1 M glycine after 22 h at 60 °C decreased by 43.9 percentage points to 37.3%, due to the lower concentration of dissolved oxygen in the system. Using hydrogen peroxide instead of oxygen as oxidant, did not improve the overall extent of copper leaching achieved.Leaching with 1 M glycine and oxygen as oxidant at 60 °C is proposed as the most feasible operating conditions within the ranges investigated, because these conditions yielded the highest copper dissolution (81.2%) with relatively low (1.3%) gold co-extraction.

A Newly Acidophilic Bacterium Acidomyces acidothermus Was Isolated to Efficiently Bioleach Copper from Waste Printed Circuit Boards (WPCBs)

An acidophilic metal-resistant bacterial strain, Acidomyces acidothermus (A. acidothermus), was isolated and identified by morphology, physiology, biochemistry, and 16S rDNA. A. acidothermus culture conditions were optimized by response surface methodology (RSM). Results showed that with a temperature of 40 °C, a pH of 3 in a 9k medium, and a rotation speed of 140 r/min, the copper leaching rate reached the highest value of 39.8%. Furthermore, SEM images and a heatmap of differential metabolites indicated that A. acidothermus adsorbed on the surface of WPCBs and extracellular polymeric substances (EPS), mainly D-glucuronic acid, were secreted, suggesting the highly efficient mechanism of copper recovery from WPCBs.

Effect of Microwave Pretreatment on the Leaching and Enrichment Effect of Copper in Waste Printed Circuit Boards.

The use of efficient and clean methods for the recycling of waste circuit boards is an ongoing challenge. In this research, the effect of microwave pretreatment on the leaching and enrichment of copper from waste print circuit board (WPCB) was studied. The morphology and chemical structure of WPCB particles before and after microwave pretreatment were analyzed by SEM/EDS and Fourier infrared spectroscopy. Leaching experiments and copper enrichment tests were designed to investigate the effect of different microwave irradiation powers and microwave irradiation times on the copper leaching rate and copper enrichment rate in WPCB. The leaching experiment results showed that microwave pretreatment can effectively improve the leaching rate of WPCB. When the microwave irradiation power was 700 W, the irradiation time was 120 s, and the leaching time was 15 min, the copper leaching rate in WPCB was 57.01%, which was 24.34% higher than that in the untreated condition. The results of copper enrichment experiment show that microwave pretreatment can effectively improve the copper enrichment of WPCB. After microwave pretreatment, copper was effectively enriched in the 4-2 and 2-1 mm particle sizes. When the microwave irradiation time was 120 s, the copper enrichment rates in the 4-2 and 2-1 mm particle sizes were 1.74 and 1.66, which increased by 0.63 and 0.32, respectively, compared to the untreated condition. Microwave pretreatment enables the effective separation of metallic copper from non-metallic components in WPCB, increasing the exposure area of copper and promoting the monomer separation of copper, thus improving the leaching and enrichment of copper.

Phase transformation mechanism of oxidation roasting of low-grade polymetallic chalcopyrite ore in the presence of CaO

Low-grade polymetallic chalcopyrite ore has a high lead and iron content and a low softening point, which is difficult to treat using conventional pyrometallurgical and hydrometallurgical processes. In order to investigate the suitable methodology for efficient utilization, it was pelletized with CaO for oxidation roasting in the present work. By controlling the Po2 and Pso2 in the gas phase, the metal sulfide in the ore was converted into easily soluble metal oxide, the thermal analysis of the roasting process was carried out and the acid leaching of the extracted calcine at atmospheric pressure was investigated. The results show that by pelletizing with CaO and then roasting at 800 ? for 1 h, chalcopyrite is converted into CuO, which can be easily dissolved, galena and pyrite are converted into PbO2 and Fe2O3, respectively, and sulfur reacts with CaO and turns into CaSO4, which can fix the sulfur in the calcine. The copper leaching rate of calcine can reach 98.60 wt.% under atmospheric pressure in the H2SO4-H2O system. CaO can increase the softening point of raw materials, improve the roasting effect, promote the phase transformation of chalcopyrite in the oxidation process, and convert sulfur into CaSO4 to fix sulfur, effectively avoiding SO2 pollution to the environment.

Comparison of sphalerite concentrate leaching by chemical and microbially produced ferric sulfate

High-temperature ferric leaching is a promising method to improve the recovery of nonferrous metals from sulfide ores and concentrates. In this study, differences in the leaching kinetics of a sphalerite concentrate using chemical and biogenic ferric iron have been revealed. A comparison of leaching with a (i) biosolution containing ferric iron produced by microbial cells assigned to the strain Leptospirillum ferriphilum BUT, (ii) cell-free iron-containing L. ferriphilum culture liquid, and (iii) commercial reagent of ferric iron indicated that the latter allowed the maximum zinc and copper extraction into the solution. It is suggested that the products of the microbial cell lysis interacted with metal cations, decreasing their reactivity, and slowed down the removal of products from the reaction zone. This led to the formation of a dense layer of reaction products coating sulfide minerals. Probably, the rate of zinc and copper leaching was controlled by both the diffusion of the oxidant through a layer of the reaction products and a chemical reaction on the surface of mineral particles, indicating a mixed type of control. This pattern was independent of the chemical or biological origin of the ferric iron solution. The results provide new insights into the kinetic patterns and structural changes of sulfide minerals during ferric leaching and may contribute to the intensification of the processing of sulfide raw materials.

Modelling in-situ recovery (ISR) of copper at the Kapunda mine, Australia

In-situ recovery (ISR) is a low-cost, percolation leaching method that recovers minerals by dissolving them in situ with a lixiviant and extracting the product through bore holes. It is widely used for uranium production and is increasingly being considered for the extraction of copper and other metals. Evaluating ISR mining projects requires a reliable prediction of the operational and commercial potential for extracting minerals by ISR. The predicted production can be evaluated by simulating the solution extraction process in the subsurface using reactive transport modelling techniques. This paper presents a case study in which the in-situ copper recovery from an abandoned mine site at Kapunda, Australia is evaluated as part of a scoping study. In this study, copper leaching and the transport of the resulting solution under well operating conditions (injection and extraction) are modelled over the mining area. COMSOL Multiphysics was used to establish an integrated simulation model of reactive fluid flow through different domains, including wells, fractured rock masses and old underground workings from previous mining operations. This paper also describes the derivation of the major input parameters from site investigations including the estimation of hydraulic conductivity from the fracture information and the copper leaching rate from the initial leaching tests. The potential for the Kapunda mine site to become the first operating in-situ copper recovery mine in Australia is currently being evaluated and the project is currently at the scoping study stage. This paper contributes to the evaluation by presenting an ISR copper production model for the Kapunda site that can be used in an initial economic analysis.

Effect of copper/nickel ratio on the efficiency of biobeneficiation of bulk copper-nickel sulfide concentrates

The dependence of the efficiency of biobeneficiation (via bioleaching) of bulk copper-nickel sulfide concentrates on the ratio of copper to nickel sulfide minerals was studied. The copper content in the concentrates ranged from 10.8 to 19.1% (copper occurred in chalcopyrite), while the content of nickel was within 4.6–9.5% (nickel occurred in pentlandite and violarite). Although the copper content was higher than the content of nickel in all concentrates, the rate of nickel leaching significantly exceeded that of copper leaching. For the concentrates characterized by copper/nickel ratio (k) equal to 1.15 and 1.5, the average nickel leaching rate was ˃8 times higher than the copper leaching rate. Bioleaching of all studied concentrates allowed the obtainment of copper concentrates in solids (copper content of 15.6–18.7%) in which nickel content was low (0.27–1.49%). The high level of nickel dissolution and the maximum increase in the copper content in the solids were shown for the concentrate with the initial copper and nickel content of 10.9 and 7.2%, respectively (k of 1.5). In this bioleach residue, the copper content increased by 4.7%, while the nickel content decreased by 6.86% compared to the original concentrate. Thus, bioleaching of copper-nickel concentrates can be considered biobeneficiation, and the highest efficacy of the process may be achieved at a copper/nickel ratio of ∼1.5.

Copper leaching from recreational vessel antifouling paints in freshwater: A Berlin case study

Copper leached from recreational vessel antifouling paints can pose a threat to aquatic organisms. To date, leaching rates have mainly been studied in seawater and brackish water. The aim of this study was to investigate the copper input from antifouling paints to freshwater using field and laboratory studies. Therefore, a large sailing area in Berlin was sampled. According to a risk assessment, the use of copper containing antifouling paints in Berlins is predicted to have no significant impact on aquatic organisms. An exception was found in sport boat marinas where, in dependence on the boat number, the sediment copper concentrations were up to 2 times higher than the German environmental quality standard for sediments. The most important result revealed by the laboratory batch tests is that the copper leaching rate in freshwater is much lower compared to seawater and brackish water. The dissolution of copper from antifouling paints into freshwater is overestimated up to now. Nevertheless, the leached copper from antifouling paints is the second largest anthropogenic copper source in the urban area of Berlin and the third largest anthropogenic copper source in German freshwaters.