Bark Ash Research Articles

Optimisation of Charcoal and Sago (Metroxylon sagu) Bark Ash to Improve Phosphorus Availability in Acidic Soils

Soil acidity is an important soil factor affecting crop growth and development. This ultimately limits crop productivity and the profitability of farmers. Soil acidity increases the toxicity of Al, Fe, H, and Mn. The abundance of Al and Fe ions in weathered soils has been implicated in P fixation. To date, limited research has attempted to unravel the use of charcoal with the incorporation of sago (Metroxylon sagu) bark ash to reduce P fixation. Therefore, an incubation study was conducted in the Soil Science Laboratory of Universiti Putra Malaysia Bintulu Sarawak Campus, Malaysia for 90 days to determine the optimum amounts of charcoal and sago bark ash that could be used to improve the P availability of a mineral acidic soil. Charcoal and sago bark ash rates varied by 25%, whereas Egypt rock phosphate (ERP) rate was fixed at 100% of the recommendation rate. Soil available P was determined using the Mehlich 1 method, soil total P was extracted using the aqua regia method, and inorganic P was fractionated using the sequential extraction method based on its relative solubility. Other selected soil chemical properties were determined using standard procedures. The results reveal that co-application of charcoal, regardless of rate, substantially increased soil total carbon. In addition, application of 75% sago bark ash increased soil pH and at the same time, it reduced exchangeable acidity, Al3+, and Fe2+. Additionally, amending acidic soils with both charcoal and sago bark ash positively enhanced the availability of K, Ca, Mg, and Na. Although there was no significant improvement in soil Mehlich-P with or without charcoal and sago bark ash, the application of these amendments altered inorganic P fractions in the soil. Calcium-bound phosphorus was more pronounced compared with Al-P and Fe-P for the soil with ERP, charcoal, and sago bark ash. The findings of this study suggest that as soil pH decreases, P fixation by Al and Fe can be minimised using charcoal and sago bark ash. This is because of the alkalinity of sago bark ash and the high affinity of charcoal for Al and Fe ions to impede Al and Fe hydrolysis to produce more H+. Thus, the optimum rates of charcoal and sago bark ash to increase P availability are 75% sago bark ash with 75%, 50%, and 25% charcoal because these rates significantly reduced soil exchangeable acidity, Al3+, and Fe2+.

Combined Use of Charcoal, Sago Bark Ash, and Urea Mitigate Soil Acidity and Aluminium Toxicity

Highly weathered tropical acidic soils are characterized by low pH, low organic matter, and aluminium and iron toxicity. These factors pose a challenge to achieving sustainable agriculture. The continued increase in the human population with the accompanied increasing food demand have negatively impacted the global N cycle partly because of excessive use N fertilizers particularly urea which is commonly used in agriculture. Ammonia volatilization from urea as an example, negatives the environmental quality. This study focuses on soil-N availability, pH, exchangeable acidity, Al3+, and H+ of a highly weathered acid soils (Bekenu series) through the combined use of charcoal, sago bark ash, and urea. To this end, an incubation study was conducted for 90 days through the combined use of charcoal, sago bark ash, and urea to determine if this approach could improve soil N availability and pH at the same time reducing exchangeable acidity, and Al3+, and H+ toxicity. The amount of urea used was fixed at 100% as the recommended rate. Charcoal and sago bark ash were varied by 25%, 50%, 75%, and 100%, respectively of the recommended rate. Selected soil physico-chemical properties were determined using standard procedures. This study revealed that combined use of charcoal, sago bark ash, and urea increased soil pH and base cations simultaneously the approach also reduced exchangeable acidity, exchangeable Al3+, and exchangeable H+. There were no significant differences in soil total N, exchangeable NH4+, and available NO3− for the combined use of charcoal, sago bark ash, and urea and urea alone because of the acid neutralizing effect of the amendments. Apart from the sago bark ash’s liming effect, the high affinity of the functional groups of the charcoal for Al3+ might have impeded Al3+ from undergoing hydrolysis to produce more H+ because a complete one mole of Al3+ hydrolysis produces three moles of H+. Thus, the combined use of charcoal and sago bark ash can mitigate soil acidity and aluminium toxicity, although this approach has minimal effect on-N.

Рост и состояние смешанных древостоев лесных насаждений Каменной Степи

By now, a vast amount of experimental material has been accumulated in the field of protective afforestation of the Central Chernozem Region of Russia, which allows estimating the stability and longevity of various trees and shrubs in different environmental conditions. Good growth and high vitality of woody vegetation largely depend on growing conditions and are determined primarily by the relationship between species (individuals within a species) when they are placed in the forest area and the type of terrain. The researchdifferent combinations in tree and shrub mixing schemes and unequal location by types of terrain. The study was carried out in mature (115–118-year-old) forest strips laid out by the staff of the Kamennaya Steppe experimental forestry G.F. Morozov and N.A. Mikhailov on the territory of the Kamennaya Steppe (Voronezh region, Talovsky district) using archival materials, scientific works of the authors of this article and the employees of the Department of Agroforestry. A comparative analysis of the materials of forest survey work carried out in protective forest plantations created according to the tree-shrub type of mixing on different types of terrain revealed an excess of biometric indicators of tree species growing on the upland type of terrain over those on the slope. It is shown that the initial percentage of participation of English oak is a significant, but not always decisive factor in the creation of oak plantations. They can also be grown with a smaller proportion of this species in the culture, but in this case, timely thinning will be of paramount importance. Over time, there have been significant changes in the composition of plantations, the number of trees and their valuation indicators. There are no viable ash and elm specimens left in the upper tier of the stands. They are severely damaged by stem pests. Certain tree species are damaged by the following pests: common ash by large ash bark beetle (Hylesinus crenatus) and ash bark beetle (Hylesinus fraxini); elm species by cambium-feeding beetles (large elm bark beetle (Scolytus scolytus), European elm bark beetle (Scolytus multistriatus), and pygmy elm bark beetle (Scolytus pygmaeus); English oak by gold pit oak splendour beetle (Chrysobothris affinis), oak borer (Agrilus angustulus), longhorn beetle (Plagionotus detritus), and European oak bark beetle (Scolytus intricatus). The predominant number of trees of all tree species belongs to the categories of limited viable and inviable.

UJI KUAT TEKAN DAYA SERAP AIR DAN MASSA JENIS BATU BATA MERAH BERBAHAN TAMBAHAN ABU KULIT DAN JANGGEL JAGUNG DI WULUHAN JEMBER

The increase in Indonesia's development activities increases people's consumption of more quality construction materials and is easy to reach in terms of price. Building materials with good quality can improve the quality of building construction. The increasing need of the community for building materials triggered the development of the brick-making industry. Redbrick is an element of building used in building construction made from clay base material with or without other mixed materials. This research is a type of experimental research. The purpose of this study is to know and analyze the composition of the addition of corn bark ash and ash corn cob appropriately to produce the quality of bricks with high compressive strength, low water absorption, and large density. Additional materials in this study in the form of corn bark ash and ash corn cob. The quality of red bricks is seen from three aspects, namely compressive strength, water absorption, and density. The largest compressive strength was obtained in the addition of ash corn cob by 2.5% by 37.2 Kg/Cm2 and the compressive strength of 49.5 Kg/Cm2 on the addition of corn skin ash by 2.5%. Water absorption measurement of all types of red bricks the results of the study showed all the results of water absorption is not eligible sni. The highest density was obtained from a mixture of 2.5% ash corn cob material of 17.5 gr/Cm3. the best composition to produce bricks with strong compressive value and high density and have low water absorption is 2.5% addition of ash corn cob and the addition of 2.5% corn skin ash.
 Keywords: Red bricks, strong press, water absorption, density.

Effect of cashew (Anacardium occidentale) nut shell stored and fresh extracts on cowpea bruchid, Callosobruchus maculatus (Fabricius.) (Coleoptera: Chrysomelidae)

Effect of cashew (Anacardium occidentale) nut shell stored and fresh extracts on cowpea bruchid, Callosobruchus maculatus (Fabricius.) (Coleoptera: Chrysomelidae)

Development of environment friendly water-based self-rechargeable battery

There is a growing demand for the development of sustainable electrical energy generation devices with a high energy-to-price ratio. On the other hand, industrial waste, such as fly ash is a hazard to environmental pollution. However, here for the first time, water-based self-rechargeable batteries have been fabricated by using bio-waste (golden shower tree bark ash (TBA)), a rural pollutant (cow dung ash), and industrial pollutant (coal fly ash). The TBA-based battery, out of all three batteries, shows the highest open-circuit voltage of ∼1.48 V and a specific capacity of 183 mAhg−1. Further, the TBA based cell has retained ∼97% columbic efficiency even after 2000 cycles. It has been found that pH of TBA ash is the highest, i.e. ∼12 in presences of tap water and it is found that the TBA ash is composed of a large number of metal oxides. The materials present in the ash powder have generated oxides and hydroxides ions which have, in turn, caused the generation of the potential difference between the two electrodes. The fabricated devices are portable and can power up a large number of electronic gadgets, including light-emitting diodes (LEDs). It is envisioned that this work may open the door to the development of sustainable, environment-friendly, and low-cost bio-waste ash-based self-rechargeable energy devices in future.

Ultrasonic extraction of onion (Allium cepa) peel dye, its applications on silk fabric with bio-mordants and its antibacterial activity

Ecofriendly natural dye was extracted ultrasonically from the red onion peel (Allium cepa). It is applied on silk fabric with and without bio-mordants. Bio-mordants used were tea leaves, tamarind, aloe vera and acacia bark ash. Colorfastness, color measurement and antibacterial properties were studied. Among colourfastness properties colourfastness to washing, light, heat, rubbing, seawater and dry-cleaning were studied. Dyed fabrics were also subjected to colour measurement values i.e Tristimulus properties (XYZ), Labs values and Munsell renotations (Hue,Vivideness and Chroma). Antibacterial properties against three strains of bacteria i.e escherichia coli, staphylococeus aureus and pseudomonas aeruginosa were also performed.

Retraction Note to: Artificial neural networks application to predict the compressive damage of lightweight geopolymer

In this work, compressive strength of lightweight geopolymers produced by fine fly ash and rice husk–bark ash together with palm oil clinker (POC) aggregates has been investigated experimentally and modeled based on artificial neural networks. Different specimens made from a mixture of fine fly ash and rice husk–bark ash with and without POC were subjected to compressive strength tests at 2, 7, and 28 days of curing. A model based on artificial neural networks for predicting the compressive strength of the specimens has been presented. To build the model, training and testing using experimental results from 144 specimens were conducted. The data used in the multilayer feed-forward neural networks models are arranged in a format of six input parameters that cover the quantity of fine POC particles, the quantity of coarse POC particles, the quantity of FA + RHBA mixture, the ratio of alkali activator to ashes mixture, the age of curing and the test trial number. According to these input parameters, in the neural networks model, the compressive strength of each specimen was predicted. The training and testing results in the neural networks model have shown a strong potential for predicting the compressive strength of the geopolymer specimens in the considered range.

SO2 Absorption by Multiple Biomass Ash Types.

As the severity of environmental pollution continues to increase and ultralow emission standards are proposed, biomass power plants must implement additional processes to control SO2 emission. Biomass ash can be utilized as a sorbent for flue gas desulfurization because of its strong alkalinity. In this study, the characteristics of SO2 absorption in simulated flue gas using four types of typical biomass ashes were studied in fixed bed experiments. The results showed that the addition of water, the increase in water vapor, and the lower temperature were beneficial for SO2 absorption. The main components of wheat straw ash are KCl and SiO2, cotton stalk ash is rich in K2O and calcium compounds, poplar bark ash has a considerable content of calcium compounds, and corncob ash contains large amounts of KCl and K2O. Alkali substances, such as oxides or carbonates of potassium and calcium, play a crucial role in SO2 absorption. The SO2 removal effect of corncob ash was the best owing to the abundance of potassium oxides. Meanwhile, wheat straw ash performed worst in SO2 removal due to the small amount of K2O and Ca. The desulfurization products were mainly potassium and calcium sulfate.

Investigating the Simultaneous Effect of Macro Fly Ash and Oak Bark Ash on Mechanical Properties of Concrete

Due to the increasing use of concrete, researchers and engineers are constantly tried to improve its mechanical and physical properties as well as its efficiency. Hence, they have made use of the most diverse products and the most modern concere technologies. In the present study, oak bark ash and macro fly ash have been used as the most widely used pozzolans in the concrete industry. The parameters of concrete and the percentages of materials used in its structure remained constant, but different percentages of oak bark ash and macro fly ash have been added to the mix design. Brazilian method and bending strength of concrete was applied. The parameters of concrete density, concrete consistency, compressive strength, and tensile strength have been investigated..Therefore, the existing materials required necessary tests; based on obtained resulted, an optimal design for the concrete mix was introduced from which the necessary specimens were taken into consideration. Then, oak bark ash was used as an additive, in proportions of 0.2 and 0.4% by the total weight of cement, and macro fly ash was used to replace cement as a variable in various proportions of 5, 10, 15 and 20% by total weight of cement. Based on the existing variables and the control design, a total of 15 groups of mix designs were introduced. The statistical population includes 45 cubic specimens (15×15×15), and 45 cylindrical specimens (15×30) for tensile strength test using Brazilian method. Also 45 bending beam specimens having dimensions of 10×10×50 were examined. Finally, after analysis of the obtained results, we dentified the superior mix design had the best performance and that both additives affected all studied parameters, including concrete consistency, density, compressive strength, tensile strength, and bending strength of concrete. However, macro fly ash had a great effect on the conrete strength. The obtained results also indicated that excessive use of any additive could have adverse effects on the mechanical properties of the concrete.

Modeling of ash (Fraxinus excelsior) bark thickness in urban forests using artificial neural network (ANN) and regression models

Bark is a protective layer in trees, as well as living texture, so estimating bark thickness is very important in future decisions in urban forestry. The purpose of this article is to compare artificial neural network (ANN) and regression modeling to prepare the most accurate model for predicting the thickness of ash bark and effective variables in the urban forestry. A total of 10 variables including age of tree, collar diameter, diameter at the breast height, slope of habitat, aspect of habitat, altitude, wind direction, direction of wind protection, direction of light on crown and direction of light on the 600 ash trees were measured. Based on SPSS analysis, the age of tree variable had the greatest effect on bark thickness. Among the models of linear regression, S model with a R2 of 0.616 was selected as the best model. Artificial neural network model was designed simulated in the Neuro-Solutions ver.5 software. Multi- layer perceptron network with two hidden layers and eight neurons makes the best function for optimizing topology with highest coefficient of determination ~ 0.830. Based on the results of sensitivity analysis, tree age was the most important factor influencing bark thickness. Finally, the model of ANN with higher coefficient of determination and less error was determined as the best model in predicting ash bark thickness in urban forests.

Retraction Note to: Fuzzy logic-based prediction of compressive strength of lightweight geopolymers

In the present work, compressive strength of lightweight inorganic polymers (geopolymers) produced by fine fly ash and rice husk–bark ash together with palm oil clinker (POC) aggregates has been investigated experimentally and modeled based on fuzzy logic. To build the model, training, validating and testing were conducted using experimental results from 144 specimens. The used data in the ANFIS models were arranged in a format of six input parameters that cover the quantity of fine POC particles, the quantity of coarse POC particles, the quantity of FA + RHBA mixture, the ratio of alkali activator to ashes mixture, the age of curing and the test trial number. According to these input parameters, in the model, the compressive strength of each specimen was predicted. The training, validating and testing results in the model have shown a strong potential for predicting the compressive strength of the geopolymer specimens in the considered range.

Retraction Note to: Artificial neural networks for prediction compressive strength of geopolymers with seeded waste ashes

In the present work, compressive strength of inorganic polymers (geopolymers) made from seeded fly ash and rice husk bark ash has been predicted by artificial neural networks. Different specimens were subjected to compressive strength tests at 7 and 28 days of curing. One set of the specimens were cured at room temperature until reaching to 7 and 28 days, and the other sets were oven-cured for 36 h at the range of 40–90 °C and then room cured until 7 and 28 days. A model based on artificial neural networks for predicting the compressive strength of the specimens has been presented. To build the model, training and testing using experimental results from 120 specimens were conducted. The data used in the multilayer feed-forward neural networks models are arranged in a format of six input parameters that cover the percentage of fine fly ash in the ashes mixture, the percentage of coarse fly ash in the ashes mixture, the percentage of fine rice husk bark ash in the ashes mixture, the percentage of coarse rice husk bark ash in the ashes mixture, the temperature of curing, and the time of water curing. According to these input parameters, in the neural networks model, the compressive strength of each specimen was predicted. The training and testing results in the neural networks model have shown a strong potential for predicting the compressive strength of the geopolymer specimens.

Retraction Note to: ANFIS-based prediction of the compressive strength of geopolymers with seeded fly ash and rice husk–bark ash

Additionally, the article shows evidence of peer review manipulation and authorship manipulation.

Natural and insecticide-free methods for protecting wood piles from bark beetles - using the example of the ash bark beetle (Hylesinus fraxini [Panzer, 1779]) on Common Ash (Fraxinus excelsior [L.

This paper is investigating the insecticide-free protection of ash wood piles through the use of semiochemical dispensers with allochthonous kairomones to control ash bark beetle populations. For this purpose, borehole counts and brood gallery analyses were carried out on log piles of ash wood stored in the forest. Studies have shown that Hylesinus fraxini is repelled by the attractant dispenser with the substance mixture Sexowit, which was actually developed to catch Ips sexdentatus. In addition, the substance mixture has an aggregating effect on various bark beetle antagonists. This causality should be used to find a form of application to protect freshly stacked ash wood from H. fraxini infestation. A recommended form of application should be transferable to other bark beetle- and tree species and substances. In adaptation to the so-called Island Method of bark beetle traps, the wood piles of the five test variants were also arranged like islands. Commercially available Sexowit pheromone dispensers were used, which were attached to the piles. Besides a control without Sexowit dispenser there were test treatments with one, two, four and nine Sexowit dispensers.Within the scope of the investigation, effects between the tested variants could be determined and a recommended application method derived. Compared to control most effective protection of ash log piles was reached with variants treated with four or nine lures of Sexowit. In relation to control infestation was reduced by 78.1% on 4-dispenser variant Sexowit and 88.9% on 9-dispenser variant Sexowit.

STW1 and Its Versatile Pharmacological and Clinical Effects in Rheumatic Disorders: A Comprehensive Report.

Aim To review the published and unpublished experimental and clinical studies about the efficacy and tolerability of STW1 and to compare the results to the efficacy and tolerability of investigated NSAIDs in parallel. Content. STW1 (Phytodolor®) contains a fixed combination of extracts from aspen leaves and bark (Populus tremula), common ash bark (Fraxinus excelsior), and goldenrod herb (Solidago virgaurea). It belongs to the group of anti-inflammatory and antirheumatic drugs, and it is authorized for the treatment of painful disorders of degenerative and inflammatory rheumatic diseases. The individual components have complementary effects. Its multifocal mode of action includes antiphlogistic, analgesic, antiexudative, antioxidative, antipyretic, and antiproliferative properties. The effects of both STW1 and its components have been verified in comprehensive pharmacological investigations. Open and randomized, placebo- and verum-controlled, and single-blind (sb) or double-blind (db) clinical trials, performed in different subtypes of rheumatic diseases confirm the pharmacological evidence. Its efficacy is comparable to a range of standard nonsteroidal anti-inflammatory drugs (NSAIDs) studied in parallel, but it has a superior safety profile. Conclusion STW1 is a reasonable alternative to NSAIDs with comparable efficacy and a superior safety profile. It is also suitable to reduce the intake of NSAIDs.

Situation and perspectives of European ash (Fraxinus spp.) in Ukraine: focus on eastern border

The health condition of European ash (Fraxinus excelsior) stands in Ukraine has become worse since 2006. Firstly, in 2011 an alien invasive pathogenic fungus Hymenoscyphus fraxineus was identified in the eastern part of the country and, subsequently, its presence was confirmed in the western and central parts. The aims of our research were to evaluate the health of ash trees and identify the main causes of ash decline in different regions of Ukraine with emphasis on ash dieback and its association with collar rots.
 Results showed that since 2013 the number of trees with ash dieback symptoms has been gradually increasing, reaching up to 92 % in 2018. Total mortality due to ash dieback was up to 9 % in 2018. Disease intensity remains high in northern and central Ukraine comparing with the east. Branch dieback, collar rots, epicormic shoots and bacterial disease of ash occurred more often in the eastern region, some symptoms were observed simultaneously. Ash bark beetle galleries, as well as foliage browsing insects, were found mostly in weakened and/or dying trees.
 It was indicated that collar rots significantly increase the mortality of ash trees. Armillaria spp. fungi were found to be frequently associated with ash dieback on living stems and fallen trees in 2017, causing high rates of mortality in the northern and central regions. For further ash conservation and breeding programmes, resistant trees in severely damaged regions should be selected to preserve genetic diversity in ash populations.
 
 Keywords: Fraxinus excelsior, ash dieback, collar rot, bacterial disease, epicormic shoots, Hymenoscyphus fraxineus, Armillaria spp.

Biomass Yield and Fuel Properties of Different Poplar SRC Clones

The goal of the research was to determine the biomass yield and fuel properties of ten different poplar clones. The research was conducted in an experimental plot established in Forest Administration Osijek, Forest Office Darda, in the spring of 2014. The layout of the plot consisted of three repetitions per clone with 40 plants per repetition in spacing 3x1 m. Based on the DBH distribution, in the early spring of 2018, one sample tree of an average DBH per repetition was selected, thus forming a sample of 30 trees. Average survival rate of the investigated trees after four vegetation periods was 74.54 ±13.85% ranging from 52.08% (Koreana) to 91.67% (SV885 and SV490). Average DBH of the sample trees was 8.2 ±1.9 cm, height 9.3 ±1.8 m and root collar diameter 10.7 ±1.9 cm. Moisture content in fresh state (just after the felling) ranged from 51.6% (Hybride 275) to 55.9% (SV885). Bark content averaged 18.4%, from 15.4% (Baldo) to 21.1% (V 609). Average nominal density of the sampled trees amounted to 383.5 ±35.9 kg/m3. Bark ash content was on average ten times higher (6.44 ±0.65%) than wood ash content (0.64 ±0.07%) resulting in average ash content of 1.7 ±0.1% (taking the bark content into account). The clone SV490 showed the highest biomass yield with 15.8 t/ha/year, while the lowest biomass yield was recorded for the clone Hybride 275 with 2.8 t/ha/year. High inter-clonal productivity variation stresses the importance of selection work to find the most appropriate clones with the highest productivity potential for the given area where the poplar SRC plantations are to be established. Due to high initial moisture content, if direct chipping harvesting systems are preferred, wood chips could be efficiently used in CHP (Combined Heat and Power) plants that operate on the principle of biomass gasification (where a gasifier is coupled to a gas engine to produce electric power and heat). In several CHP gasification plants operating in Croatia, wood chips with high initial moisture content (from traditional poplar plantations) are used as a feedstock that has to be pre-dried using the surplus heat. In this respect SRC poplar wood chips could make an ideal feedstock supplement.

Suitability study of secondary raw materials for prevention of acid rock drainage generation from waste rock

Prevention and mitigation of acid rock drainage (ARD) from mine wastes are crucial for limiting environmental impact. However, preventive measures are often too expensive, potentially harmful to the environment or not applied early enough. This study aimed to test the potential of different secondary raw materials for maintaining a circumneutral pH (6–7) in a sulfide oxidation environment, allowing secondary minerals to form on reactive sulfide surfaces to prevent release of acid, metals and metalloids, and thereby ARD generation. Five materials (blast furnace slag, granulated blast furnace slag, cement kiln dust, bark ash, lime kiln dust) were selected based on their alkaline properties, availability and yearly yield. High sulfidic (>50 wt%, sulfide) waste rock from an active Cu–Zn–Au–Ag open pit mine in northern Sweden was leached in small-scale laboratory test cells under ambient condition for 4–8 weeks before adding secondary raw materials on the surface in an attempt to prevent ARD generation. During 52 subsequent weeks of leaching, the pH and electrical conductivity in the leachate from the waste rock varied between 1.7-4.6 and 2.1–22.8 mS/cm, respectively. All secondary raw materials were able to increase the pH to circumneutral. However, blast furnace slag, granulated blast furnace slag and cement kiln dust were not able to maintain a circumneutral pH for an extended time due to self-cementation or carbonation, whereas bark ash (1 wt%) and lime kiln dust (5 wt%) prevented acidity, metal and metalloid leaching. Materials such as cement kiln dust and bark ash contained elevated concentrations of, e.g., Cd and Zn, but the release of metals and metalloids was generally low for most elements, except for Cl, K and Na, most likely due to salt dissolution.

Enhanced soil washing with copper recovery using chemical precipitation

Worldwide, the number of contaminated sites is large, and remediation methods including recovery of metals have potential to be key aspects of a sustainable and circular economy. Soil washing, followed by chemical precipitation is a possible method for recovery of metals. The purpose of this study is to propose a complete recovery method, where Cu is efficiently leached from samples with contaminated bark ash and soil. Thereafter the Cu is precipitated as metal hydroxide. The results show that pH is the most important parameter that controls the leaching of Cu. The leaching process was independent of the liquid to solid ratio (L/S) for the soil, while the leaching increased with the L/S ratio for the bark ash. The shaking method used for leaching affected the results, as a low leaching efficiency was achieved with the turn-over-end technique used. The final Cu precipitation product from the bark ash contained ≥40 wt % Cu, whereas the corresponding soil precipitation product contained ≤15 wt % Cu. The conclusion is that the bark ash precipitation product is of interest for further refining within the metal industry. Due to inefficient leaching and washing, the soil and bark ash residues left after leaching are classified as hazardous waste.