Assessing the Feasibility of Biorefineries for a Sustainable Citrus Waste Management in Korea.

Citrus fruits are one of the most widely used fruits around the world and are used as raw fruits, but are also processed into products such as beverages, and large amounts of by-products and waste are generated in this process. Globally, disposal of citrus waste (CW) through simple landfilling or ocean dumping can result in soil and groundwater contamination, which can negatively impact ecosystem health. The case of Korea is not much different in that these wastes are simply buried or recycled wastes are used as livestock feed additives. However, there are many reports that CW, which is a waste, has high potential to produce a variety of products that can minimize environmental load and increase added value through appropriate waste management. In this study, we aim to explore the latest developments in the evaluation and valorization of the growing CW green technologies in an effort to efficiently and environmentally transform these CW for resource recovery, sustainability, and economic benefits. Recent research strategies on integrated biorefinery approaches have confirmed that CW can be converted into various bioproducts such as enzymes, biofuels and biopolymers, further contributing to energy security. It was found that more efforts are needed to scale up green recovery technologies and achieve diverse product profiling to achieve zero waste levels and industrial viability.

PEIPNet: Parametric Efficient Image-Inpainting Network with Depthwise and Pointwise Convolution.

Research on image-inpainting tasks has mainly focused on enhancing performance by augmenting various stages and modules. However, this trend does not consider the increase in the number of model parameters and operational memory, which increases the burden on computational resources. To solve this problem, we propose a Parametric Efficient Image InPainting Network (PEIPNet) for efficient and effective image-inpainting. Unlike other state-of-the-art methods, the proposed model has a one-stage inpainting framework in which depthwise and pointwise convolutions are adopted to reduce the number of parameters and computational cost. To generate semantically appealing results, we selected three unique components: spatially-adaptive denormalization (SPADE), dense dilated convolution module (DDCM), and efficient self-attention (ESA). SPADE was adopted to conditionally normalize activations according to the mask in order to distinguish between damaged and undamaged regions. The DDCM was employed at every scale to overcome the gradient-vanishing obstacle and gradually fill in the pixels by capturing global information along the feature maps. The ESA was utilized to obtain clues from unmasked areas by extracting long-range information. In terms of efficiency, our model has the lowest operational memory compared with other state-of-the-art methods. Both qualitative and quantitative experiments demonstrate the generalized inpainting of our method on three public datasets: Paris StreetView, CelebA, and Places2.

Arterial Blood Gas Analysis for Survival Prediction in Pediatric Patients with Out-of-Hospital Cardiac Arrest.

Arterial blood gas analysis (ABGA) is one of the few tests performed during cardiopulmonary resuscitation (CPR). There have been some studies on the prediction of survival outcomes in adult out-of-hospital cardiac arrest (OHCA) patients during CPR using ABGA results. However, in pediatric OHCA patients, the prognosis of survival outcome based on ABGA results during CPR remains unclear. We retrospectively analyzed prospectively collected data from the Korean Cardiac Arrest Resuscitation Consortium (KoCARC) registry, a multicenter OHCA registry of Republic of Korea. We analyzed 108 pediatric (age < 19 years) OHCA patients between October 2015 and June 2022. Using multivariable logistic regression, an adjusted odds ratio (aOR) was obtained to validate the ABGA results of survival to hospital admission and survival to discharge. The variables associated with survival to hospital admission were non-comorbidities (aOR 3.03, 95% confidence interval (CI) 1.22-7.53, p = 0.017) and PaO2 > 45.750 mmHg (aOR 2.69, 95% CI 1.13-6.42, p = 0.026). There was no variable that was statistically significant association with survival to discharge. PaO2 > 47.750 mmHg and non-comorbidities may serve as an independent prognostic factor for survival to hospital admission in pediatric OHCA patients. However, the number of cases analyzed in our study was relatively small, and there have been few studies investigating the association between ABGA results during CPR and the survival outcome of pediatric OHCA patients. Therefore, further large-scale studies are needed.

A Numerical Study of an Ellipsoidal Nanoparticles under High Vacuum Using the DSMC Method.

The semiconductor and display manufacturing process requires high precision. Therefore, inside the equipment, fine impurity particles affect the yield rate of production. However, since most manufacturing processes are performed under high-vacuum conditions, it is difficult to estimate particle flow with conventional analytical tools. In this study, high-vacuum flow was analyzed using the direct simulation Monte Carlo (DSMC) method, and various forces acting on fine particles in a high-vacuum flow field were calculated. To compute the computationally intensive DSMC method, GPU-based computer unified device architecture (CUDA) technology was used. The force acting on the particles in the high-vacuum rarefied gas region was verified using the results of previous studies, and the results were derived for the difficult-to-experiment region. An ellipsoid shape with an aspect ratio rather than a spherical shape was also analyzed. The change in drag force according to various aspect ratios was analyzed and compared with the results of the spherical shape under the same flow conditions.

Phytochemistry and Applications of Cinnamomum camphora Essential Oils.

Camphor tree (Cinnamomum camphora) is an ornamental plant that has been cultivated for a long time to obtain wood or camphor. Furthermore, its essential oil can be used as an alternative medicine and is an important source of perfume. Camphor obtained from camphor trees has long been used as a treatment for various symptoms such as inflammation, infection, congestion, muscle pain, and irritation in various regions. The purpose of this literature review is to provide knowledge of the well-established, wide, and extensive applications of camphor both in traditional and modern applications. Despite many studies focused on the essential oil of the camphor tree, there is a lack of systematic studies of its extraction or separation. Besides, various components of camphor are not fully understood, and further research is needed on the medicinal effects of individual components of C. camphor. The genus Cinnamomum has crucial economic value and theoretical significance. However, further systematic reviews and investigative studies based on existing research are needed to promote the modernization process of traditional applications of camphor. For proper use of the essential oil of C. camphora, it is imperative to consider its possible effects on humans and the environment.

Revitalization of Total Petroleum Hydrocarbon Contaminated Soil Remediated by Landfarming.

Soil health deteriorates through the contamination and remediation processes, resulting in the limitation of the reuse and recycling of the remediated soils. Therefore, soil health should be recovered for the intended purposes of reuse and recycling. This study aimed to evaluate the applicability and effectiveness of several amendments to revitalize total petroleum hydrocarbon contaminated soils remediated by the landfarming process. Ten inorganic, organic, and biological amendments were investigated for their dosage and duration, and nine physicochemical, four fertility, and seven microbial (soil enzyme activity) factors were compared before and after the treatment of amendments. Finally, the extent of recovery was quantitatively estimated, and the significance of results was confirmed with statistical methods, such as simple regression and correlation analyses assisted by principal component analysis. The landfarming process is considered a somewhat environmentally friendly remediation technology to minimize the adverse effect on soil quality, but four soil properties-such as water holding capacity (WHC), exchangeable potassium (Ex. K), nitrate-nitrogen (NO3-N), available phosphorus (Av. P), and urease-were confirmed to deteriorate through the landfarming process. The WHC was better improved by organic agents, such as peat moss, biochar, and compost. Zeolite was evaluated as the most effective material for improving Ex. K content. The vermicompost showed the highest efficacy in recovering the NO3-N content of the remediated soil. Chlorella, vermicompost, and compost were investigated for their ability to enhance urease activity effectively. Although each additive showed different effectiveness according to different soil properties, their effect on overall soil properties should be considered for cost-effectiveness and practical implementation. Their overall effect was evaluated using statistical methods, and the results showed that compost, chlorella, and vermicompost were the most relevant amendments for rehabilitating the overall health of the remediated soil for the reuse and/or recycling of agricultural purposes. This study highlighted how to practically improve the health of remediated soils for the reuse and recycling of agricultural purposes.

Evaluation of Two Amendments (Biochar and Acid Mine Drainage Sludge) on Arsenic Contaminated Soil Using Chemical, Biological, and Ecological Assessments.

Various types of organic and inorganic materials are widely examined and applied into the arsenic (As) contaminated soil to stabilize As bioavailability and to enhance soil quality as an amendment. This study deals with two types of amendments: biochar for organic amendment and acid mine drainage sludge (AMDS) for inorganic amendment. Each amendment was applied in two types of As contaminated soils: one showed low contaminated concentration and acid property and the other showed high contaminated concentration and alkali property. In order to comprehensively evaluate the effect of amendments on As contaminated soil, chemical (As bioavailability), biological phytotoxicity (Lactuca sativa), soil respiration activity, dehydrogenase activity, urease activity, ß-glucosidase activity, and acid/alkali phosphomonoesterase activity, an ecological (total bacterial cells and total metagenomics DNA at the phylum level) assessment was conducted. Both amendments increased soil pH and dissolved organic carbon (DOC), which changes the bioavailability of As. In reducing phytotoxicity to As, the AMDS was the most effective regardless of soil types. Although soil enzyme activity results were not consistent with amendments types and soil types, bacterial diversity was increased after amendment application in acid soil. In acid soil, the results of principal component analysis represented that AMDS contributes to improve soil quality through the reduction in As bioavailability and the correction of soil pH from acidic to neutral condition, despite the increases in DOC. However, soil DOC had a negative effect on As bioavailability, phytotoxicity and some enzyme activity in alkali soil. Taken together, it is necessary to comprehensively evaluate the interaction of chemical, biological, and ecological properties according to soil pH in the decision-making stages for the selection of appropriate soil restoration material.

Evaluation of factors affecting arsenic uptake by Brassica juncea in alkali soil after biochar application using partial least squares path modeling (PLS-PM).

Biochar application to As-contaminated soil can alter various soil chemical properties, and it can affect available As, plant As uptake, and As phytotoxicity. Increased dissolved organic carbon (DOC) and P released from biochar affect As behavior in the soil system. In this study, we evaluated the effect of biochar application on the chemical properties of soil and phytotoxicity in Brassica juncea using correlation analysis and partial least squares path modeling (PLS-PM). Biochar application increased electrical conductivity (EC), DOC, available P and available As. However, the increased available As did not significantly affect As uptake by B. juncea due to the decrease in the relative ratio and effect of available As with increase in available P derived from biochar. Moreover, biochar application negatively affected soil chemical properties (pH, EC, DOC, available P, and available As) and As uptake by B. juncea. Therefore, correlation analysis and PLS-PM analysis are useful tools to interpret the interactions among influencing factors in the soil-plant system. An approach at the equivalent molecular level rather than concentration should be adopted in future studies.

RF Transceiver for the Multi-Mode Radar Applications.

In this work, a multi-mode radar transceiver supporting pulse, FMCW and CW modes was designed as an integrated circuit. The radars mainly detect the targets move by using the Doppler frequency which is significantly affected by flicker noise of the receiver from several Hz to several kHz. Due to this flicker noise, the long-range detection performance of the radars is greatly reduced, and the accuracy of range to the target and velocity is also deteriorated. Therefore, we propose a transmitter that suppresses LO leakage in consideration of long-range detection, target distance, velocity, and noise figure. We also propose a receiver structure that suppresses DC offset due to image signal and LO leakage. The design was conducted with TSMC 65 nm CMOS process, and the designed and fabricated circuit consumes a current of 265 mA at 1.2 V supply voltage. The proposed transmitter confirms the LO leakage suppression of 37 dB at 24 GHz. The proposed receiver improves the noise figure by about 20 dB at 100 Hz by applying a double conversion architecture and an image rejection, and it illustrates a DC rejection of 30 dB. Afterwards, the operation of the pulse, FMCW, and CW modes of the designed radar in integrated circuit was confirmed through experiment using a test PCB.

Human Health Risk Assessment for Toxic Trace Elements in the Yaro Mine and Reclamation Options.

The aim of this study was to investigate the environmental impact and human health risks associated with toxic trace element (TTE) exposure in the abandoned Yaro Mine, Korea. Carcinogenic and non-carcinogenic risks were assessed separately for adults and children. Among the various pathways, the rate of TTE intake from the ingestion of groundwater was highest, followed in descending order by crop consumption, soil ingestion, and soil contact. The carcinogenic risk from the ingestion of groundwater was highest, followed by crop consumption and ingestion of contaminated surface soil. The non-carcinogenic risk from the ingestion of groundwater was highest (53.57% of the total non-carcinogenic risk), followed by crop intake (38.53%) and surface soil ingestion (4.80%). The risk assessment revealed that contaminated soil around Yaro mine posed a high risk to the health of inhabitants, mainly via groundwater ingestion and crop consumption. Reclamation measures should include methods of disrupting the high-risk routes between the source and recipient. Stabilization and covering techniques are promising options for reducing the hazard (i.e., exposure to the bioavailable fraction of TTE) and creating a chemical or physicochemical barrier to the potential migration pathways.

Bardoxolone ameliorates TGF-ß1-associated renal fibrosis through Nrf2/Smad7 elevation.

Transforming growth factor-ß (TGF-ß) is a potent pathogenic factor of renal injury through the upregulation of extracellular matrix (ECM) expression and facilitation of renal fibrosis. Nuclear factor erythroid 2-like 2 (Nfe2l2; Nrf2), a master regulator of antioxidant and detoxifying systems, is mainly controlled by the binding with cytosolic protein Kelch-like ECH-associated protein 1 (Keap1) and subsequent proteasomal degradation. The protective effect of Nrf2 on renal injury has been attributed to its antioxidant role, where it aids in coping with oxidative stress-associated progression of renal disease. In this study, we investigated the effect of Nrf2 activation on ECM production and TGF-ß/Smad signaling using Keap1-silenced MES-13 cells (a genetic glomerular mesangial cell model with Nrf2 overexpression). The TGF-ß1-inducible expression of fibronectin and α-smooth muscle actin (α-Sma) was suppressed and Smad2/3 phosphorylation was blocked in Nrf2-high mesangial cells as compared with that in control cells. Notably, in these Nrf2-high mesangial cells, levels of TGF-ß1 receptor 1 (TßR1) were substantially diminished, and the protein levels of Smad7, an inhibitor TGF-ß1/Smad signaling, were increased. Nrf2-mediated Smad7 elevation and its anti-fibrotic role in Keap1-silenced cells were confirmed by studies with Nrf2-or Smad7-silencing. As a molecular link for Smad7 elevation in Nrf2-high cells, the reduction of Smad-ubiquitination-regulatory factor 1 (Smurf1), an E3 ubiquitin ligase for Smad7, was notable. Silencing of Smurf1 increased Smad7 in the control mesangial cells; however, forced expression of Smurf1 repressed Smad7 levels in Keap1-silenced cells. Additionally, we demonstrate that bardoxolone (BARD; CDDO-methyl), a pharmacological activator of Nrf2, increased Smad7 levels and attenuated TGF-ß/Smad/ECM expression in MES-13. Moreover, in an aristolochic acid (AA)-mediated nephropathy mouse model, the renal expression of Nrf2 and Smad7 was elevated by BARD treatment, and AA-induced tubular necrosis and interstitial fibrosis were substantially ameliorated by BARD. Collectively, these results indicate that the Nrf2-Smad7 axis plays a key role in the protection of TGF-ß-induced renal fibrosis, and further suggest a novel molecular mechanism of beneficial effect of BARD on renal disease.

Embryos of an Antarctic zooplankton require anoxia for dormancy, are permeable to lipophilic chemicals, and reside in sediments containing PCBs.

Zooplankton in Antarctic maritime lakes face challenges imposed by anthropogenic chemicals. Studies on temperate species suggest that lipophilic chemicals will accumulate in dormant embryos of Antarctic zooplankton and decrease hatching success, thereby threatening centuries of accumulated genetic diversity that would increase population resilience in the face of climate change. We evaluated the potential for lakes to act as sinks for legacy pollutants in the maritime Antarctic by testing sediments for polychlorinated biphenyls (PCBs) previously identified in soil, flora and fauna of lake catchments. Direct tests of embryo permeability to chemicals are confounded by potential adhesion of chemicals to the embryo surface and limited biomass available. Therefore, in order to assess the potential for lipophilic chemicals to penetrate and passively accumulate in dormant embryos of Antarctic lacustrine zooplankton, we evaluated the effect of anoxia on post-diapause development in the calanoid copepod, Boeckella poppei, and then used chemical anoxia induced by rotenone as a reporter for permeability of these embryos to moderately lipophilic chemicals. The data presented demonstrate that embryos of B. poppei from Antarctic lake sediments will passively accumulate moderately lipophilic chemicals while lying dormant in anoxic sediments. Implications for legacy POPs in sediments of Antarctic maritime lakes are discussed.

The Effects of Various Amendments on Trace Element Stabilization in Acidic, Neutral, and Alkali Soil with Similar Pollution Index.

Many studies have examined the application of soil amendments, including pH change-induced immobilizers, adsorbents, and organic materials, for soil remediation. This study evaluated the effects of various amendments on trace element stabilization and phytotoxicity, depending on the initial soil pH in acid, neutral, and alkali conditions. As in all types of soils, Fe and Ca were well stabilized on adsorption sites. There was an effect from pH control or adsorption mechanisms on the stabilization of cationic trace elements from inorganic amendments in acidic and neutral soil. Furthermore, acid mine drainage sludge has shown great potential for stabilizing most trace elements. In a phytotoxicity test, the ratio of the bioavailable fraction to the pseudo-total fraction significantly affected the uptake of trace elements by bok choy. While inorganic amendments efficiently decreased the bioavailability of trace elements, significant effects from organic amendments were not noticeable due to the short-term cultivation period. Therefore, the application of organic amendments for stabilizing trace elements in agricultural soil requires further study.

Involvement of NRF2 Signaling in Doxorubicin Resistance of Cancer Stem Cell-Enriched Colonospheres.

Cancer stem cells (CSCs) are a subset of tumor cells, which are characterized by resistance against chemotherapy and environmental stress, and are known to cause tumor relapse after therapy. A number of molecular mechanisms underlie the chemoresistance of CSCs, including high expression levels of drug efflux transporters. We investigated the role of the antioxidant transcription factor NF-E2-related factor 2 (NRF2) in chemoresistance development, using a CSC-enriched colonosphere system. HCT116 colonospheres were more resistant to doxorubicin-induced cell death and expressed higher levels of drug efflux transporters such as P-glycoprotein (Pgp) and breast cancer resistance protein (BCRP) compared to HCT116 monolayers. Notably, levels of NRF2 and expression of its target genes were substantially elevated in colonospheres, and these increases were linked to doxorubicin resistance. When NRF2 expression was silenced in colonospheres, Pgp and BCRP expression was downregulated, and doxorubicin resistance was diminished. Collectively, these results indicate that NRF2 activation contributes to chemoresistance acquisition in CSC-enriched colonospheres through the upregulation of drug efflux transporters.

Redox Modulating NRF2: A Potential Mediator of Cancer Stem Cell Resistance.

Tumors contain a distinct small subpopulation of cells that possess stem cell-like characteristics. These cells have been called cancer stem cells (CSCs) and are thought to be responsible for anticancer drug resistance and tumor relapse after therapy. Emerging evidence indicates that CSCs share many properties, such as self-renewal and quiescence, with normal stem cells. In particular, CSCs and normal stem cells retain low levels of reactive oxygen species (ROS), which can contribute to stem cell maintenance and resistance to stressful tumor environments. Current literatures demonstrate that the activation of ataxia telangiectasia mutated (ATM) and forkhead box O3 (FoxO3) is associated with the maintenance of low ROS levels in normal stem cells such as hematopoietic stem cells. However, the importance of ROS signaling in CSC biology remains poorly understood. Recent studies demonstrate that nuclear factor-erythroid 2-related factor 2 (NRF2), a master regulator of the cellular antioxidant defense system, is involved in the maintenance of quiescence, survival, and stress resistance of CSCs. Here, we review the recent findings on the roles of NRF2 in maintenance of the redox state and multidrug resistance in CSCs, focusing on how NRF2-mediated ROS modulation influences the growth and resistance of CSCs.

The effectiveness of spent coffee grounds and its biochar on the amelioration of heavy metals-contaminated water and soil using chemical and biological assessments.

Spent coffee grounds (SCG) and charred spent coffee grounds (SCG-char) have been widely used to adsorb or to amend heavy metals that contaminate water or soil and their success is usually assessed by chemical analysis. In this work, the effects of SCG and SCG-char on metal-contaminated water and soil were evaluated using chemical and biological assessments; a phytotoxicity test using bok choy (Brassica campestris L. ssp. chinensis Jusl.) was conducted for the biological assessment. When SCG and SCG-char were applied to acid mine drainage, the heavy metal concentrations were decreased and the pH was increased. However, for SCG, the phytotoxicity increased because a massive amount of dissolved organic carbon was released from SCG. In contrast, SCG-char did not exhibit this phenomenon because any easily released organic matter was removed during pyrolysis. While the bioavailable heavy metal content decreased in soils treated with SCG or SCG-char, the phytotoxicity only rose after SCG treatment. According to our statistical methodology, bioavailable Pb, Cu and As, as well as the electrical conductivity representing an increase in organic content, affected the phytotoxicity of soil. Therefore, applying SCG during environment remediation requires careful biological assessments and evaluations of the efficiency of this remediation technology.

Influence of amendments and aided phytostabilization on metal availability and mobility in Pb/Zn mine tailings.

A greenhouse experiment was conducted to evaluate the effect of four different amendments, bone mill, bottom ash, furnace slag, and red mud, as immobilizing agents and the plant species Miscanthus sinensis and Pteridium aquilinum in aided phytostabilization of Pb/Zn mine tailings. The effects of amendments and plants on the availability and mobility of heavy metals were evaluated using single extraction, sequential extraction, pore-water analysis, and determination of heavy metal concentrations in plants. The application of Fe-rich amendments significantly reduced the amount of soluble and extractable heavy metals in the tailings (p < 0.05). Furnace slag and M. sinensis reduced CaCl2-extractable heavy metals by 56-91%, red mud and P. aquilinum treatment was the most effective at decreasing bioaccessible Pb, reducing it to 34% of the total Pb. Compared to control, water soluble Cd, Cu, Pb, and Zn were reduced by 99, 99, 98, and 99%, respectively, in the red mud and P. aquilinum tailings. M. sinensis accumulated heavy metals mainly in the root, and had lower translocation factors compared with P. aquilinum. The results of this study suggest that M. sinensis can be used in aided phytostabilization for these types of mine tailings and Fe-rich amendments are effective for the in situ immobilization of metals.

Involvement of the Nrf2-proteasome pathway in the endoplasmic reticulum stress response in pancreatic ß-cells.

The ubiquitin-proteasome system plays a central role in protein quality control through endoplasmic reticulum (ER)-associated degradation (ERAD) of unfolded and misfolded proteins. NF-E2-related factor 2 (Nrf2) is a transcription factor that controls the expression of an array of phase II detoxification and antioxidant genes. Nrf2 signaling has additionally been shown to upregulate the expression of the proteasome catalytic subunits in several cell types. Here, we investigated the role of Nrf2 in tunicamycin-induced ER stress using a murine insulinoma ß-cell line, ßTC-6. shRNA-mediated silencing of Nrf2 expression in ßTC-6 cells significantly increased tunicamycin-induced cytotoxicity, elevated the expression of the pro-apoptotic ER stress marker Chop10, and inhibited tunicamycin-inducible expression of the proteasomal catalytic subunits Psmb5 and Psmb6. The effects of 3H-1,2-dithiole-3-thione (D3T), a small molecule Nrf2 activator, on ER stress were also examined in ßTC-6 cells. D3T pretreatment reduced tunicamycin cytotoxicity and attenuated the tunicamycin-inducible Chop10 and protein kinase RNA-activated-like ER kinase (Perk). The protective effect of D3T was shown to be associated with increased ERAD. D3T increased the expression of Psmb5 and Psmb6 and elevated chymotrypsin-like peptidase activity; proteasome inhibitor treatment blocked D3T effects on tunicamycin cytotoxicity and ER stress marker changes. Similarly, silencing of Nrf2 abolished the protective effect of D3T against ER stress. These results indicate that the Nrf2 pathway contributes to the ER stress response in pancreatic ß-cells by enhancing proteasome-mediated ERAD.

Arsenic mobility in the amended mine tailings and its impact on soil enzyme activity.

The objectives of this study were to elucidate the effects of soil amendments [Ferrous sulfate (Fe(II)), red mud, Fe(II) with calcium carbonate (Fe(II)/L) or red mud (RM/F), zero-valent iron (ZVI), furnace slag, spent mushroom waste and by-product fertilizer] on arsenic (As) stabilization and to establish relationships between soil properties, As fractions and soil enzyme activities in amended As-rich gold mine tailings (Kangwon and Keumkey). Following the application of amendments, a sequential extraction test and evaluation of the soil enzyme activities (dehydrogenase and ß-glucosidase) were conducted. Weak and negative relationships were observed between water-soluble As fractions (As(WS)) and oxalate extractable iron, while As(WS) was mainly affected by dissolved organic carbon in alkaline tailings sample (Kangwon) and by soil pH in acidic tailings sample (Keumkey). The soil enzyme activities in both tailings were mainly associated with As(WS). Principal component and multiple regression analyses confirmed that As(WS) was the most important factor to soil enzyme activities. However, with some of the treatments in Keumkey, contrary results were observed due to increased water-soluble heavy metals and carbon sources. In conclusion, our results suggest that to simultaneously achieve decreased As(WS) and increased soil enzyme activities, Kangwon tailings should be amended with Fe(II), Fe(II)/L or ZVI, while only ZVI or RM/F would be suitable for Keumkey tailings. Despite the limitations of specific soil samples, this result can be expected to provide useful information on developing a successful remediation strategy of As-contaminated soils.