Peel Residues Research Articles

Preparation of citrus fiber from lemon peel residue: Effects of structure and endogenous pectin components on emulsifying properties of citrus fiber

Preparation of citrus fiber from lemon peel residue: Effects of structure and endogenous pectin components on emulsifying properties of citrus fiber

Blue LED light improves the antioxidant composition of Valencia oranges during postharvest: Impact on orange juice, pulp portion and peel residue

Valencia orange is the major citrus fruit produced worldwide and its outstanding health benefits are well-established. However, there is a pressing need to further enhance the nutritional quality of fruits and to revalorize the resulting residues, providing benefits for both public health and the environment. Here, Valencia oranges were exposed to blue LED light for 30 days at room temperature in controlled environment chambers, using darkness as a control. Examination of the blue LED light effects was performed focusing on visual aspects, weight loss, organoleptic properties, antioxidant content and oxidation status, together with the analysis of the phytohormonal profile. Blue LED light was found to boost fruit weight loss, particularly through dehydration of the peel, without altering pulp firmness or external appearance. Organoleptic quality, including texture and flavor, as well as total soluble sugar and acidity remained unchanged. Notably, blue LED light increased antioxidant levels, more specifically vitamin C and total phenols in the juice, and enhanced total antioxidant capacity in the peel. This suggests that blue LED light can enhance nutritional quality while preserving organoleptic properties. The increase in antioxidants is likely a protective response against photooxidative stress induced by the blue LED light. These findings highlight the potential of blue LED light to improve postharvest fruit quality with direct health benefits and support a circular economy by enhancing the value of orange peel waste.

Extraction of bioactive compounds from peel and seeds of pitomba (Talisia esculenta) using eutectic solvents

SummaryThis study explores using pitomba peel and seeds to obtain a natural extract with high antioxidant capacity, employing extraction techniques with eutectic solvents combined with agitation and temperature control. The analysis revealed that, for the extraction with pitomba peel residues, the average levels of phenolic compounds did not show significant differences except for the extraction with ethanol. In contrast, the extractions performed with pitomba seeds showed significant differences, with the combination of choline chloride with lactic acid and choline chloride with glycerol providing the highest phenolic compound values. For flavonoids, the highest amount was obtained with the extraction using L‐proline and levulinic acid for the pitomba peel and ethanol and choline chloride with levulinic acid for the pitomba seeds. The results of the DPPH and FRAP assays indicate that, for antioxidant activity, the highest DPPH value was achieved with the extraction of pitomba peel using choline chloride with glycerol. In contrast, for pitomba seeds, elevated values were found with choline chloride with glycerol and choline chloride with levulinic acid. In the FRAP assay, the averages between L‐proline with levulinic acid and choline chloride with glycerol were not significantly different, showing high values. For pitomba seeds, the averages between ethanol and choline chloride with glycerol were also not significantly different and showed the highest obtained values. The results demonstrate that the extracts obtained from pitomba residues are rich in valuable compounds for potential applications in the food and pharmaceutical industries. They highlight the significant levels of flavonoids extracted from pitomba peel and seeds and emphasise the effectiveness of deep eutectic solvents (DES), particularly choline chloride with glycerol, in the extraction process.

Hyaluronic acid production by Streptococcus zooepidemicus MW26985 using potato peel waste hydrolyzate.

In this research, we examined the production of hyaluronic acid (HA) by Streptococcus zooepidemicus strain MW26985 using different substrates and potato peel waste (PPW) as an affordable substrate. First, culture medium components, including carbon and nitrogen sources, were optimized for bacterial HA production. Five different carbon sources (glucose, sucrose, lactose, sago starch, and potato starch, at a concentration of 30g/L) and three distinct nitrogen sources (peptone, yeast extract, and ammonium sulfate, at a concentration of 10g/L) were investigated. Glucose, among the carbon sources, and yeast extract, among nitrogen sources, produced the most HA which was determined as 1.41g/L. Afterward, potato peel sugars were extracted by dilute acid and enzymatic hydrolysis and then employed as a cost-effective carbon source for the growth of S. zooepidemicus. Based on the results, the fermentation process yielded 0.59g/L HA from potato peel sugars through acid hydrolysis and 0.92g/L HA from those released by enzymatic hydrolysis. The supplementation of both hydrolyzates with glucose as an additional carbon source enhanced HA production to 0.95g/L and 1.18g/L using acidic and enzymatic hydrolyzates, respectively. The cetyltrimethylammonium bromide (CTAB) turbidimetric method was used to evaluate the concentration of HA in the fermentation broth using the colorimetric method. Also, the peaks observed by Fourier transform infrared (FTIR) spectroscopy confirmed that the exopolysaccharide (EPS) was composed of HA. These observations demonstrate that potato peel residues can be a novel alternative as a carbon source for the economical production of HA by S. zooepidemicus.

Effect of Molasses Addition on the Fermentation Quality and Microbial Community during Mixed Microstorage of Seed Pumpkin Peel Residue and Sunflower Stalks

Effect of Molasses Addition on the Fermentation Quality and Microbial Community during Mixed Microstorage of Seed Pumpkin Peel Residue and Sunflower Stalks

Enhancing Cutin Extraction Efficiency from Industrially Derived Tomato Processing Residues by High-Pressure Homogenization.

This study primarily aimed to enhance the extraction of cutin from industrial tomato peel residues. Initially, the conventional extraction process was optimized using response surface methodology (RSM). Subsequently, high-pressure homogenization (HPH) was introduced to improve extraction efficiency and sustainability. The optimization process focused on determining the optimal conditions for conventional extraction via chemical hydrolysis, including temperature (100-130 °C), time (15-120 min), and NaOH concentration (1-3%). The optimized conditions, determined as 130 °C, 120 min, and 3% NaOH solution, yielded a maximum cutin extraction of 32.5%. Furthermore, the results indicated that applying HPH pre-treatment to tomato peels before alkaline hydrolysis significantly increased the cutin extraction yield, reaching 46.1%. This represents an approximately 42% increase compared to the conventional process. Importantly, HPH pre-treatment enabled cutin extraction under milder conditions using a 2% NaOH solution, reducing NaOH usage by 33%, while still achieving a substantial cutin yield of 45.6%. FT-IR analysis confirmed that cutin obtained via both conventional and HPH-assisted extraction exhibited similar chemical structures, indicating that the main chemical groups and structure of cutin remained unaltered by HPH treatment. Furthermore, cutin extracts from both conventional and HPH-assisted extraction demonstrated thermal stability up to approximately 200 °C, with less than 5% weight loss according to TGA analysis. These findings underscore the potential of HPH technology to significantly enhance cutin extraction yield from tomato peel residues while utilizing milder chemical hydrolysis conditions, thereby promoting a more sustainable and efficient cutin extraction process.

Exploring the integration of orange peel for sustainable gluten-free flatbread making

In response to the growing demand for sustainable and nutritious gluten-free (GF) products, this study explore orange peel by-products as a breadmaking ingredient of GF rice or corn flatbreads. The orange peel powder exhibited remarkable water retention properties attributed to its high dietary fiber content. Partial pre-gelatinization of rice (64 g/100 g) and corn (67 g/100 g) flour allowed obtaining doughs with sufficient consistency and extensibility to obtain GF flatbreads. The inclusion of orange peel powder (0–9 g/100 g) influenced the consistency and thermal behavior of the dough. Modifying hydration levels mitigated the hardness resulting from orange peel powder substitution, leading to improved folding properties. Final products exhibited enhanced nutritional profiles, including higher ash and dietary fiber content. The optimum nutritional and technological outcomes were observed when employing the maximum substitution rate of 9 g/100 g, along with adjusted hydration (164 g/100 g for corn and 169 g/100 g for rice), with notable emphasis on the improved extensibility of the final products. Compared to rice-based flatbreads, corn-based flatbreads displayed more uniform dough consistency, lower gelatinization enthalpy, higher yellowness, and decreased extensibility due to the stiffer dough texture. This study suggests that orange peel residue holds significant promise as a nutritional and technological enhancer for gluten-free flatbreads.

Bioinformatics-based identification of GH12 endoxyloglucanases in citrus-pathogenic Penicillium spp

Millions of tons of citrus peel waste are produced every year as a byproduct of the juice industry. Citrus peel is rich in pectin and xyloglucan, but while the pectin is extracted for use in the food industry, the xyloglucan is currently not valorized. To target hydrolytic degradation of citrus peel xyloglucan into oligosaccharides, we have used bioinformatics to identify three glycoside hydrolase 12 (GH12) endoxyloglucanases (EC 3.2.1.151) from the citrus fruit pathogens Penicillium italicum GL-Gan1 and Penicillium digitatum Pd1 and characterized them on xyloglucan obtained by alkaline extraction from citrus peel. The enzymes displayed pH-temperature optima of pH 4.6–5.3 and 35–37°C. PdGH12 from P. digitatum and PiGH12A from P. italicum share 84% sequence identity and displayed similar kinetics, although kcat was highest for PdGH12. In contrast, PiGH12B from P. italicum, which has the otherwise conserved Trp in subsite −4 replaced with a Tyr, displayed a 3 times higher KM and a 4 times lower kcat/KM than PiGH12A, but was the most thermostable enzyme of the three Penicillium-derived endoxyloglucanases. The benchmark enzyme AnGH12 from Aspergillus nidulans was more thermally stable and had a higher pH-temperature optimum than the enzymes from Penicillum spp. The difference in structure of the xyloglucan oligosaccharides extracted from citrus peel xyloglucan and tamarind xyloglucan by the new endoxyloglucanases was determined by LC-MS. The inclusion of citrus peel xyloglucan demonstrated that the endoxyloglucanases liberated fucosylated xyloglucan oligomers, implying that these enzymes have the potential to upgrade citrus peel residues to produce oligomers useful as intermediates or bioactive compounds.

Acremonium sp. diglycosidase-aid chemical diversification: valorization of industry by-products

The fungal diglycosidase α-rhamnosyl-β-glucosidase I (αRβG I) from Acremonium sp. DSM 24697 catalyzes the glycosylation of various OH-acceptors using the citrus flavanone hesperidin. We successfully applied a one-pot biocatalysis process to synthesize 4-methylumbellipheryl rutinoside (4-MUR) and glyceryl rutinoside using a citrus peel residue as sugar donor. This residue, which contained 3.5 % [w/w] hesperidin, is the remaining of citrus processing after producing orange juice, essential oil, and peel-juice. The low-cost compound glycerol was utilized in the synthesis of glyceryl rutinoside. We implemented a simple method for the obtention of glyceryl rutinoside with 99 % yield, and its purification involving activated charcoal, which also facilitated the recovery of the by-product hesperetin through liquid-liquid extraction. This process presents a promising alternative for biorefinery operations, highlighting the valuable role of αRβG I in valorizing glycerol and agricultural by-products.Keypoints• αRβG I catalyzed the synthesis of rutinosides using a suspension of OPW as sugar donor.• The glycosylation of aliphatic polyalcohols by the αRβG I resulted in products bearing a single rutinose moiety.• αRβG I catalyzed the synthesis of glyceryl rutinoside with high glycosylation/hydrolysis selectivity (99 % yield).Graphical

Novel Electromagnetic Heat Hydrodistillation for Extraction of Essential Oil from Tangerine Peel.

A novel electromagnetic heat method is presented for green extraction of natural compounds from peel residue. In the processing cavity obtained through 3D printing, a core made of amorphous alloy was applied to strengthen the magnetic flux. During the process, an induced electric field was produced in the extract medium owing to an oscillating magnetic field at 50 kHz rather than a pair of electrodes; thus, electrochemical reactions could be avoided. A thermal effect and temperature rise were observed under the field, and essential oil was obtained via this electromagnetic heat hydrodistillation. In addition, the numerical relationships between magnetic field, induced electric field (IEF), induced current density, and temperature profile were elaborated; they were positively correlated with the extraction yield of essential oils. It was found that the waveforms of the magnetic field, induced electric field, and excitation voltage were not consistent. Using a higher magnetic field resulted in high current densities and terminal temperatures in the extracts, as well as higher essential oil yields. When the magnetic field strength was 1.39 T and the extraction time was 60 min, the maximum yield of essential oil reached 1.88%. Meanwhile, conventional hydrodistillation and ohmic heating hydrodistillation were conducted for the comparison; all treatments had no significant impact on the densities. In addition, the essential oil extracted by electromagnetic heat had the lowest acid value and highest saponification value. The proportion of monoterpenoids and oxygen-containing compounds of essential oil extracted by this proposed method was higher than the other two methods. In the end, the development of this electromagnetic heat originating from magnetic energy has the potential to recover high-value compounds from biomass waste.

Nickel ion adsorption from water by Nano Fe2O3/PP prepared from pomegranate peel residue and treated magnetically

In this study, biochar produced from pomegranate peels and treated by magnetization was prepared in the treatment of water contaminated with nickel ions. The percentage of nickel removal at a weight of (0.025) mg/L of magnetized biochar was (98.761%) at a concentration of (15 ppm), and the percentage of nickel removal under the influence of the acid function was (99.188%) where pH=3 at the same weight and concentration, while the percentage of nickel removal at the shaking time was (99.402%) at a shaking time of 15 minutes and a weight of 0.025 mg/L and a concentration of 15 ppm. As for the impact of temperature on the adsorption process, we find that the amount of adsorption of nickel ions increases with increasing temperature. This indicates that the adsorption process is an endothermic process. This means that the value of ΔH is a positive value. This indicates the presence of an absorption and adsorption process at the same time, weight, concentration, pH value 3, and temperature 328 is (99.615%). From the results, we find that the amount of adsorbed material increases as the weight of the adsorption material Nano Fe2O3/PP decreases. This is due to the increase in the surface area of the material, as the nickel ion is linked to the active sites by electrostatic forces.

Valorization of Prickly Pear Peel Residues (Opuntia ficus-indica) Using Solid-State Fermentation.

Prickly pear peel (Opuntia ficus-indica) residues can be used as a substrate in solid-state fermentation to obtain bioactive compounds. The kinetic growth of some Aspergillus strains was evaluated. A Box-Hunter and Hunter design to evaluate the independent factors was used. These factors were temperature (°C), inoculum (spores/g), humidity (%), pH, NaNO3 (g/L), MgSO4 (g/L), KCl (g/L), and KH2PO4 (g/L). The response factors were the amount of hydrolyzable and condensed tannins. The antioxidant and antimicrobial activity of fermentation extracts was evaluated. Aspergillus niger strains GH1 and HT3 were the best for accumulating tannins. The humidity, inoculum, and temperature affect the release of hydrolyzable and condensed tannins. Treatment 13 (low values for temperature, inoculum, NaNO3, MgSO4; and high values for humidity, pH, KCl, KH2PO4) resulted in 32.9 mg/g of condensed tannins being obtained; while treatment 16 (high values for all the factors evaluated) resulted in 3.5 mg/g of hydrolyzable tannins being obtained. In addition, the fermented extracts showed higher antioxidant activity compared to the unfermented extracts. Treatments 13 and 16 showed low inhibition of E. coli, Alternaria sp., and Botrytis spp. The solid-state fermentation process involving prickly pear peel residues favors the accumulation of condensed and hydrolyzable tannins, with antioxidant and antifungal activity.

The Progressive Utilization of Ponkan Peel Residue for Regulating Human Gut Microbiota through Sequential Extraction and Modification of Its Dietary Fibers.

As a by-product of citrus processing, ponkan (Citrus reticulata Blanco, cv. Ponkan) peel residue is a source of high quality dietary fiber (DF). To make a full utilization of this resource and give a better understanding on the probiotic function of its DF, soluble dietary fiber (SDF) and insoluble dietary fiber (IDF) were extracted from ponkan peel residue (after flavonoids were extracted) using an alkaline method, followed by modifications using a composite physical-enzymatic treatment. The in vitro fermentation properties of the modified SDF and IDF (namely, MSDF and MIDF) and their effects on short-chain fatty acids (SCFA) production and changes in the composition of human gut microbiota were investigated. Results showed that MSDF and MIDF both significantly lowered the pH value and enhanced total SCFA content in the broths after fermented for 24 h by fecal inocula (p < 0.05) with better effects found in MSDF. Both MSDF and MIDF significantly reduced the diversity, with more in the latter than the former, and influenced the composition of human gut microbiota, especially increasing the relative abundance of Bacteroidetes and decreasing the ratio of Firmicutes to Bacteroidetes (F/B) value. The more influential microbiota by MSDF were g-Collinsella, p-Actinobacteria and g-Dialister, while those by MIDF were f-Veillonellaceae, c-Negativicutes and f-Prevotellacese. These results suggested that the modified ponkan peel residue DF can be utilized by specific bacteria in the human gut as a good source of fermentable fiber, providing a basis for the exploitation of the citrus by-product.

Ultrasonic-Microwave extraction of glucoside alkaloids from potato peel residue and its antibacterial activity

A new extraction and bacteriostatic ability of glucoside alkaloids in potato peel. To make better use of glucoside alkaloids, this experiment adopted ultrasonic microwave combined extraction of glucoside alkaloids from potato peel; then, the extracts of potato peel were subjected to bacteriostatic assays. The optimum experimental condition of response surface method was that the solid-liquid ratio was 1:18.00 g/mL, the ultrasonic power 505.00 W, the microwave time was 6.10 min and the ultrasonic time was 10.70 min. Under those conditions, the extraction amount of glucoside alkaloids was 292.91 mg/kg, which increased by about 28% compared with the QUEChERS method. The antibacterial activity of the obtained glucoside alkaloids was tested using five kinds of strains, and the results showed that Penicillium and Colletotrichum gloeosporioides were more sensitive. The results indicated that Ultrasonic-Microwave combined extraction was more efficient and convenient than that of QuEChERS method for glucoside alkaloids and related antibacterial compounds from potato peel.

Effect of coating material on microencapsulated phenolic compounds extracted from agroindustrial ciriguela peel residue.

Extract of ciriguela residue was microencapsulated by spray-drying and freeze-drying using maltodextrin (M), gum arabic (GA) and their mixture (50% M; 50% GA on dry basis) as encapsulating agents. Total phenolic compounds (TPC), antioxidant activity, physicochemical properties, profile of phenolic compounds by HPLC with diode-array detection and storage stability were evaluated. TPC content of powders ranged from 306.9 to 451.2 mg gallic acid equivalent g-1 dry powder. The spray-dried powder prepared using GA as encapsulating agent had higher TPC content and antioxidant activity, whereas the freeze-dried powder had lower moisture and water activity. Spray-dried microcapsules had spherical shape, whereas freeze-dried products had irregular structures. The profile of phenolic compounds identified in samples was similar, with rutin (342.59 and 72.92 μg g-1 ) and quercetin (181.02 and 43.24 μg g-1 ) being the major compounds in liquid and freeze-dried extracts, respectively, whereas myricetin (97.41 μg g-1 ) was predominant in spray-dried ones. Storage stability tests carried out for 45 days at 7 or 25 °C revealed no statistically significant difference in TPC. Ciriguela residue can be considered a source of TPC and used as ingredient with good antioxidant activity in the food industry. © 2023 Society of Chemical Industry.

Improving the quality of soluble dietary fiber from Poria cocos peel residue following steam explosion.

Poria cocos peel residue (PCPR) still contains much soluble dietary fiber (SDF), steam explosion (SE) treatment was applied to PCPR to create a superior SDF. Steam pressure of 1.2MPa, residence period of 120s, and moisture content of 13% were the optimized parameters for SE treatment of PCPR. Under optimized circumstances, SE treatment of PCPR enhanced its SDF yield from 5.24% to 23.86%. Compared to the original SDF, the SE-treated SDF displayed improved enzyme inhibition, including the inhibition of α-amylase and pancreatic lipase, also enhanced water holding, oil holding, water swelling, nutrient adsorption including cholesterol, nitrite ions, and glucose and antioxidant abilities. Additionally, it had a decreased molecular weight, improved thermal stability, and a rough surface with many pores of different sizes. Given that SDF had been improved physiochemical and functional characteristics thanks to SE treatment, it might be the excellent functional ingredient for the food business.

Nanostructured sustainable carbon derived from biomass as catalyst support for alumina in catalytic methanol conversion to DME as hydrogen carrier

A novel series of nanostructured catalysts composed of Al2O3 supported on a phosphorous (P) modified mesoporous carbon (ACP) derived from orange peel residues was formed. The formed, 1−7% (w/w) alumina/ACP, catalysts were investigated for conversion of methanol to dimethyl ether (DME) as a promising hydrogen carrier. The catalysts were characterized with a group of standard characterization techniques. Increasing of alumina loading caused remarkable structural and textural changes. Thus, new bands due to Al–O–P was detected by ATR−FTIR, which was confirmed by XPS as due to surface AlPO4 species. However, no crystalline Al2O3 and/or AlPO4 nanoparticles were detected by XRD or HRTEM. Meanwhile, the mesoporous surface texture was preserved. The loading of alumina led to increasing of Brønsted acidic sites population. The catalyst exhibited high conversion of methanol and complete selectivity for DME at low, DME formation rate of 17.88 and 19.85 mmol g−1 h−1 at 300 and 350 °C, respectively. The catalyst efficiency is among the most efficient traditional and recently reported catalysts. Thus, the work showed successful biomass valorization into efficient, selective, low price catalysts that facilitate hydrogen storage via conversion of methanol to DME. This conversion, which is advantageous in transportation and distribution as H2 carrier, will in fact support and advance the UN's sustainable development goals.

Sustainable biodiesel production from waste cooking oil using banana peel biochar-Fe2O3/Fe2K6O5 magnetic catalyst

Addressing environmental challenges and energy resource scarcity, this study focuses on biodiesel production through the transesterification of waste cooking oil with methanol. To facilitate the reaction, a novel heterogeneous catalyst, derived from waste banana peels and composed of biochar-Fe2O3/Fe2K6O5, was employed. The magnetic acid–base catalyst was prepared by carbonating banana peel residue with Fe(III) and potassium hydroxide activator under N2 gas at 700 °C for 2 h. Extensive analysis of the physical and chemical properties of the biochar-based catalyst, including electron microscope analysis, X-ray diffraction, Fourier transform spectroscopy, thermal analysis, and vibration magnetometer techniques, was conducted. The study also explored the influence of crucial parameters on biodiesel yield from waste cooking oil using the biochar-Fe2O3/Fe2K6O5 catalyst. These parameters included the molar ratio of methanol to oil (ranging from 5 to 9 mol/mol), catalyst amount (2–6 wt%), temperature (40–80 °C), and reaction time (1–5 h). Results indicated that optimal conditions for achieving a biodiesel yield of 88.83% were a methanol to oil molar ratio of 7:1, a catalyst amount of 4 wt% for a reaction time of 3 h at 60 °C. The resulting biodiesel exhibited promising properties, including a density of 0.883 g/cm3, a kinematic viscosity of 4.37 mm2/s, and a flash point of 147 °C. The findings of this study highlight the substantial implications and practical benefits of employing rational engineering techniques in the utilization of biochar-Fe2O3/Fe2K6O5 as an exceptionally efficient, stable, and readily recoverable catalyst for the sustainable production of biodiesel from waste oil.

Reinforcement of urea formaldehyde resins with pectins derived from orange peel residues for the production of wood-based panels

Pectin is a high molecular weight carbohydrate polymer that can be utilized in various applications in many sectors. The current study involved extracting pectin samples from orange peel residues and utilizing them as additives in water-based adhesive systems for producing composite wood panels. Three pectin types were used, named Pectin-A (extracted from orange peels with HCl), pectin-B (extracted from orange peels with H2SO4) and a commercial pectin called Pectin-C. The aim of the study was to examine the possibility of enhancing the efficacy of wood-based panels, such as particleboard, by strengthening amino resins like urea-formaldehyde resin (UF) using pectin samples. Three methods were utilized to incorporate the pectins into the adhesive systems: pectin 0.1% w/w dry/liquid resin added during the initial (1) and final (2) stage of the resin’s synthesis and pectin 0.1% w/w dry/liquid resin was incorporated into the glue mixture (3), which was then sprayed onto wood particles for the production of particleboard (PB) panels. It was found that pectins improve the performance of the final particleboards, especially when added during the UF resin synthesis. In addition, they may provide the adhesive and wood panel producers with a more environmentally friendly bio-additive for their products.

Oxalic acid enhanced removal of heavy metal and pesticide by peroxymonosulphate activation with a green biochar iron composite: Reactivity and mechanism

Nowadays, clean-up of heavy metals and pesticides from environment has received great attention. A green biochar iron composite (PC-ZVI) was successfully synthesized using pomelo peel residues and FeCl3 solution. Peroxymonosulfate (PMS) was introduced into the PC-ZVI system for Cr(VI) and atrazine (AE) removal, and results showed that PMS greatly promoted Cr(VI) and AE removal. The presence of oxalic acid (OA) could maintain a relatively high dissolved Fe2+ species for Cr(VI) reduction and AE oxidation in the PC-ZVI/PMS process. The contribution order of reactive oxygen species followed as HO• > SO4•- greater than1O2 > O2•− in both Cr(VI) and AE removal by PC-ZVI/PMS/OA process. A total of six intermediates products of AE degradation were detected, and AE molecular was effectively degraded into CO2, H2O, inorganic N and Cl through hydroxylation, substitution and de-alkylation processes. The underlying mechanism of Cr(VI) and AE removal by PC-ZVI/PMS/OA process was also proposed. Most Cr(VI) species were transformed into Cr2O3 and Cr(OH)3 through reduction and precipitation processes. PC-ZVI has a relatively high recyclability toward both Cr(VI) and AE removal from solutions. The potential toxicity of PC-ZVI solution was small at three PC-ZVI dosages levels, and the corresponding toxicity of AE reaction solution by PC-ZVI/PMS/OA process decreased as reaction time increased. The order of both Cr(VI) and AE removal in different water systems was tap water > river water > lake water > wastewater, and this PC-ZVI/PMS/OA process exhibited the better adaptability in application for several actual water environments.