Lemon Peel Waste Research Articles

Carbon Dioxide Adsorption over Activated Biocarbons Derived from Lemon Peel.

The rising concentration of CO2 in the atmosphere is approaching critical levels, posing a significant threat to life on Earth. Porous carbons derived from biobased materials, particularly waste byproducts, offer a viable solution for selective CO2 adsorption from large-scale industrial sources, potentially mitigating atmospheric CO2 emissions. In this study, we developed highly porous carbons from lemon peel waste through a two-step process, consisting of temperature pretreatment (500 °C) followed by chemical activation by KOH at 850 °C. The largest specific surface area (2821 m2/g), total pore volume (1.39 cm3/g), and micropore volume (0.70 cm3/g) were obtained at the highest KOH-to-carbon ratio of 4. In contrast, the sample activated with a KOH-to-carbon ratio of 2 demonstrated the greatest micropore distribution. This activated biocarbon exhibited superior CO2 adsorption capacity, reaching 5.69 mmol/g at 0 °C and 100 kPa. The remarkable adsorption performance can be attributed to the significant volume of micropores with diameters smaller than 0.859 nm. The Radke-Prausnitz equation, traditionally employed to model the adsorption equilibrium of organic compounds from liquid solutions, has been shown to be equally applicable for describing the gas-solid adsorption equilibrium. Furthermore, equations describing the temperature dependence of the Radke-Prausnitz equation's parameters have been developed.

Bioethanol Production from Citrus limon (Citrus) Peel Substrate Using Aspergillus Niger and Saccharomyces Cerevisae

Study’s Excerpt An approach to optimizing bioethanol production from lemon peel waste is presented. A combination of Aspergillus niger for enzymatic hydrolysis and Saccharomyces cerevisiae for fermentation were employed and specific physicochemical conditions—such as a pH of 3.5, temperature of 30°C, and 96-hour fermentation period—that maximize bioethanol yield and fermentation efficiency were highlighted. Citrus limon peel has a potential of becoming sustainable bioethanol source that could contributes to renewable energy development. Full Abstract The consumption of petroleum products is marred by the inconveniences of environmental pollution and the emission of greenhouse gases, which are responsible for global warming. Excessive use of fossil fuel has resulted in climate change, the elevation of the greenhouse gas effect, etc., contributing to the search for renewable sources of energy in harmony with the world’s energy needs. Although bioconversion of lignocellulose residue has received much attention, most plant biomass has not been fully exploited to meet human energy needs. Among these alternative energy carriers, ethanol receives great attention. This study aims to determine the optimal conditions for the production of bioethanol from lemon peel using Aspergillus Niger and Saccharomyces cerevisae. Aspergillus niger and Saccharomyces cerevisiae were isolated using the streak plate method and identified macroscopically and microscopically. The cellulose hemicellulose and lignin contents of the substrates were determined, and after that, the substrates were pretreated with 5% sulfuric acid and then subjected to enzymatic hydrolysis using Aspergillus niger. Subsequently, the reducing sugar content of the hydrolysate was determined, followed by fermentation using Saccharomyces cerevisae. The percentage of bioethanol produced, as well as the fermentation efficiency (%), were calculated. Analysis of Variance was employed to determine statistically significant differences among the determined parameters. The cellulose, hemicellulose, and lignin contents of Citrus Limon were found to be 32.00%, 4.99%, and 9.80%. Pretreatment increased the cellulose content from 23.00% to 32.00%. The highest reducing sugar content, 6.63 g/L,, was recorded after hydrolysis for 96 hours. Fermentation using Saccharomyces cerevisae yielded 19.20% of bioethanol from Citrus limon with a fermentation efficiency of 38.42%, respectively. The Optimum fermentation conditions recorded were a time of 96hrs, pH of 3.5, temperature of 30oC and amount of substrate of 15g. The combination of these parameters produced a bioethanol yield of (22.90%) and a fermentation efficiency of 44.44%, respectively. This research revealed the potential of Citrus limon peel waste as a substrate for bioethanol production and optimized the physicochemical parameters for the fermentation.

Preliminary study of mixing used cooking oil and lemon peel essential oil as an alternative fuel to replace biodiesel

Biodiesel is an environmentally friendly renewable bio-energy with many advantages over diesel fuel. The disadvantage of biodiesel is that the price is still relatively expensive so it cannot compete with diesel fuel. This high price is due to the high cost of raw materials and manufacturing process costs. Raw materials such as palm oil, methanol and methyl acetate are expensive, and the transesterification and interesterification processes require long process stages that require a lot of energy supply. The solution to overcome this problem is to use cheap raw materials and a simple manufacturing process. Used cooking oil is household waste that has prospects as a raw material. Another ingredient used is lemon essential oil. Lemon essential oil can be made yourself by extracting lemon peel waste using a boiling or steaming process. The lemon essential oil used is also small, namely a maximum of 5% of the mass of used cooking oil. It is hoped that mixing used cooking oil with lemon essential oil can replace biodiesel. Lemon essential oil is a bio-additive that can improve the quality of used cooking oil to approach the physical properties of biodiesel. With this new process, it is hoped that it can produce fuel that is cheap but of good quality. The aim of the research is to obtain a new fuel to replace biodiesel that is cheaper and more efficient, namely with cheap raw materials and fewer process stages so that it will reduce production costs. The research began with the activation of zeolite as an adsorbent for purifying used cooking oil with variables including zeolite mass of 400 grams, calcination temperature of 300⁰C, activation time of 2 hours and zeolite size > 80 mesh. The second stage of the research was purifying used cooking oil with zeolite using a variable volume of 3 liters of used cooking oil and a purification time of 1 hour. The third stage of the research was mixing purified used cooking oil with lemon essential oil with variable volume of essential oil (3, 4, 5, 6, 7% oil volume) and mixing temperature (30, 40, 50⁰C), mixing time 60 minutes, stirring speed 500 rpm and oil volume 150 mL. After the mixing time and the sample temperature reached room temperature, an analysis of the density, acid number, viscosity and FFA of used cooking oil with bio-additive lemon essential oil was carried out. The analysis results are compared with the biodiesel standard SNI 7182-2015 to see whether the product/sample approaches the physical properties of biodiesel

Characterization of the essential oil content of lemon (Citrus limon burm f.) peel and the active component of the cohobation waste

Lemon (Citrus limon burm f.) peel is a waste from processing lemons that has not been utilized optimally. One effort to utilize lemon peel waste is by extracting essential oils. In the process of extracting essential oils of lemon peel, a waste by-product will be produced in the form of solid waste (cohobation waste). In order to increase the economic value of lemon peel, it is necessary to evaluate the content of active components in the cohobation waste of the lemon peel extraction process. This study aims to examine the essential oil components in lemon peel and the active components contained in the cohobation waste resulted from the extraction process. The essential oil extraction method used was cohobation. The testing method used was the Gas Chromatography Mass Spectrometry (GCMS). The results showed that the essential oil components extracted from lemon peel were: d-limonene (79.38%), citral (5.98%), neral (3.62%), 3-cyclohexene-1-methanol, α.,α.4-trimethyl-3-cyclohexene-1-methanol (2.94%), linalool (2%), β-myrcene (1.18%), and p-mentha-1,5-dien-8-ol (1.85%). While the results of the cohobation waste test contained various active components, such as: 9,12 octadecadienoic acid (20.66%), g-sitosterol (11.47%), hexadecanoic acid (9.85%), β-bisabolene (9.45%), β-fenchol (7.57%), α-bergamotene (5.47%), vitamin E (2.57%), and campesterol (2.24%).

Synthesis of porous and activated carbon from lemon peel waste for CO2 adsorption

The concentration of CO2 in the atmosphere has been increasing and is soon to reach a threatening level for life on the planet. Porous carbons made from biobased materials including from waste resources can be applied to selectively adsorb CO2 from large industrial sites and then lower atmospheric CO2 emissions. In this work, we synthesized highly porous carbons from lemon-peel wastes using two-step activation process involving hydrothermal carbonization followed by chemical activation with KOH, and KOH + alum at 800 °C. The sample activated with KOH + alum has the highest BET surface area (2143 m2/g) and total pore volume of 1.3 cc/g. Although the KOH activated sample has a lower surface area (1113 m2/g), it has better CO2 adsorption capacity ranging up to 4.5 mmol/g because of its well-developed pore structures and a high proportion (90 %) of micropore distributions. The isosteric heat of adsorption lower than 40 kJ/mol indicated that adsorption is mainly driven by physisorption. Better CO2/N2 selectivity suggested a high affinity of the activated carbons towards CO2. Particularly, the sample activated with KOH had selectivity in the range of 20 at the highest adsorption temperature (40 °C), making it a potentially viable option for direct CO2 adsorption applications from large industrial sources.

Bio-Sustainable Alternatives Synthesis of Nanoporous Activated Carbon @Al-MOF for the Adsorption of Hazardous Organic Dyes from Wastewater

The disposal of textile pollutants tainted by soluble organic dyes into the water without proper treatment may adversely impact the aquatic environment, humans, plants, and animals due to their toxic nature. As a result, the goal of this work is to look into the adsorptive removal of Eriochrome Black T (EBT) dye (as a model of soluble anionic organic dyes) from aqueous solution using a green synthesis nanoporous activated carbon @ Aluminum based metal–organic frameworks (AC@Al-MOFs) from a lemon peel waste as an inexpensive biosorbent. The physicochemical properties of Al-MOF and AC@Al-MOF composite were characterized by X-ray diffraction (XRD), Fourier transforms infrared spectroscopy (FTIR), Brunauer–Emmett–Teller (BET), scanning electron microscopy (SEM), and the impact of varied parameters on adsorption efficiency of Eriochrome Black T (EBT) including pH, dye concentrations, contact time and adsorbent dose, was examined. The experimental isotherms data were analyzed using Langmuir and Freundlich isotherm equations. The best fit was obtained by the Langmuir model with high correlation coefficients (R2 = 0.9976) with a maximum monolayer adsorption capacity of 303.0 mg/g. The results suggest that AC@Al-MOF composite is a potential choice for removing EBT dye molecules from aqueous media.Graphical

Engineered biochar derived from lemon peel waste for highly efficient removal of organic pollutants from water

The urgent need for efficient decontamination of organic dyes from polluted waters necessitates the search for a low-cost and suitable adsorbent. The large amount of lemon peel residue in actual production can be an ideal raw material for the preparation of adsorbents. Herein, a novel magnetic nanocomposite derived from lemon (Citrus limon L.) peel residue (Fe3O4/Lp-biochar) was successfully synthesized by one-step hydrothermal method and used for the adsorptive capture of methylene blue (MB) in aqueous solution. The prepared Fe3O4/Lp-biochar are spherical with a particle size of 8.3 nm and have a saturation magnetization intensity of 52.9 emu/g and a specific surface area of 64.30 m2/g. It was found that the maximum MB adsorption capacity of 26.36 mg/g by the Fe3O4/Lp-biochar can be achieved when the amount of nanocomposite was 0.10 mg/mL, the system's pH value was 10, the reaction temperature was 25 °C, and the adsorption time was 60 min. Adsorption kinetics of MB on the Fe3O4/Lp-biochar followed the pseudo-second-order kinetic model whilst the Freundlich isotherm model could well simulate the adsorption behavior of MB on magnetic biochar. The adsorption mechanism of MB by the Fe3O4/Lp-biochar predominantly include electrostatic attraction and mesoporous interaction. Furthermore, the Fe3O4/Lp-biochar exhibited a remarkable retention of 94.7% of the initial adsorption efficiency even after the 10th cycle of repeated use. It was concluded that the lemon peel-derived magnetic biochar can be a promising alternative to conventional adsorbents for wastewater treatment.

Bioactivity of non-extractable phenolics from lemon peel obtained by enzyme and ultrasound assisted extractions

Lemon peel waste constitutes a natural resource for bioactive phenolics with antioxidant, antihypertensive and antidiabetic activities. Bioactivities of non-extractable phenolics from lemon peel obtained by conventional heat-, enzyme-, ultrasound-, and ultrasound-enzyme-assisted extractions were evaluated in comparison with those of extractable phenolics. The antioxidant, angiotensin-I-converting enzyme (ACE), and α-amylase inhibitory activities and phenolic profile of the phenolic fractions were analysed. While the extractable fraction had higher total phenolic content, ascorbic acid content, and antioxidant activity, phenolic profile analysis indicated that the non-extractable fraction contained higher concentrations of phenolics especially hesperidin and hesperetin. The concentrations of hesperidin and hesperetin in the non-extractable fraction were 270.9 mg/100 g dry weight and 415.9 mg/100 g dry weight, respectively, which were about two-fold higher than those present in the extractable fraction. Moreover, ACE and α-amylase inhibitory activities of non-extractable fraction were stronger than those of the extractable fraction. Total phenolic content, total flavonoid content, and antioxidant activity were increased by enzyme and ultrasound treatments compared to those by conventional heat treatment. However, ACE inhibitory activities of all non-extractable fractions were similar while α-amylase inhibitory activity was higher in ultrasound- and ultrasound-enzyme-treated fractions. While ultrasound-assisted extraction slightly improved the yield of non-extractable phenolics, enzyme-assisted extraction yielded two-to four-fold increases in the amounts of phenolic compounds compared to heat-assisted extraction. Non-extractable phenolic fraction from lemon peel was found to have a significant potential as an antihypertensive and antidiabetic agent.

Effect of purple sugarcane peel extracts on properties of films based on lemon peel waste pectin and the application in the visible detection of food freshness

In this work, the effect of purple sugarcane (Saccharum officinarum) peel anthocyanin extracts (PSPAEs) on the physical and functional properties of films based on lemon peel waste pectin (LPP) was investigated for the first time. PSPAEs have great compatibility with LPP matrix, and the LPP/PSPAEs composite film demonstrated a higher ultraviolet light barrier capacity. The incorporation of PSPAEs significantly improved the physical properties of LPP films confirmed by the enhanced mechanical properties and thermal stability, which might be associated with the more compact structure observed by scanning electron microscope images and possible intermolecular interaction such as hydrogen bond interactions between film components demonstrated via Fourier transform infrared spectra and X-ray diffraction analysis. Furthermore, PSPAEs imparted excellent functional properties on LPP films, including antioxidant properties and sensitive color response to the pH alternation and ammonia atmosphere, which favored the possible application in monitoring food freshness. Herein, LPP/PSPAEs films were employed to detect the freshness of shrimp and beef, and a visually discernible color change could be observed as the food turned from fresh to stale. In addition, the LPP/PSPAEs composite films displayed great biodegradability in the soil. The results showed that could impart excellent properties on LPP films, and LPP/PSPAEs composite film is a promising biodegradable film that can be used for intelligent detection of food freshness.

Green Synthesis of Magnetic Nanoparticles of Iron Oxide Using Aqueous Extracts of Lemon Peel Waste and Its Application in Anti-Corrosive Coatings

Lately, the development of green chemistry methods with high efficiency for metal nanoparticle synthesis has become a primary focus among researchers. The main goal is to find an eco-friendly technique for the production of nanoparticles. Ferro- and ferrimagnetic materials such as magnetite (Fe3O4) exhibit superparamagnetic behavior at a nanometric scale. Magnetic nanoparticles have been gaining increasing interest in nanoscience and nanotechnology. This interest is attributed to their physicochemical properties, particle size, and low toxicity. The present work aims to synthesize magnetite nanoparticles in a single step using extracts of green lemon Citrus Aurantifolia residues. The results produced nanoparticles of smaller size using a method that is friendlier to health and the environment, is more profitable, and can be applied in anticorrosive coatings. The green synthesis was carried out by a co-precipitation method under variable temperature conditions. The X-ray Diffraction (XRD) and Transmission Electron Microscopy (TEM) characterization showed that magnetite nanoparticles were successfully obtained with a very narrow particle size distribution between 3 and 10 nm. A composite was produced with the nanoparticles and graphene to be used as a surface coating on steel. In addition, the coating's anticorrosive behavior was evaluated through electrochemical techniques. The surface coating obtained showed good anticorrosive properties and resistance to abrasion.

Pyrolysis of lemon peel waste in a fixed-bed reactor and characterization of innovative pyrolytic products

Lemon peel waste (LPW) were pyrolysed in a laboratory fixed-bed reactor at final temperature of 300 °C, 400 °C and 500 °C with an incremental heating rate of 10 °C/min, under N2 atmosphere to produce biochar, bio-oil and gas. The maximum yields of bio-oil, biochar and gas were 16.66 wt%, 66.89 wt% and 54.6 wt%, respectively, at 400 °C, 300 °C and 500 °C. The produced gas has a maximum calorific value around 12 MJ/N m3 with a composition up to 68.82 vol.% of CO, 5.25 vol.% of CH4, 1.48 vol.% of CnHm. The recovered biochar is a promising applicant for the manufacturing of carbon materials and for solid fuel applications. The bio-oil chemical characterization using GC–MS and FTIR spectroscopy shows its richness with bioactive compounds such as squalene, d-limonene, ß-Sitosterol and phenol. Biochar and bio-oil showed bactericidal activity against Bacillus cereus, Micrococcus luteus, Salmonella enterica, Listeria monocytogenes and Staphylococcus aureus. Pyrolytic products of LPW show large potential applications in agriculture and agri-food industry and allow a sustainable biomass-waste management with promising economic benefits.

Biodegradable and Active Mulch Films: Hydrolyzed Lemon Peel Waste and Low Methoxyl Pectin Blends with Incorporated Biochar and Neem Essential Oil

Biodegradable and Active Mulch Films: Hydrolyzed Lemon Peel Waste and Low Methoxyl Pectin Blends with Incorporated Biochar and Neem Essential Oil

Extracellular enzyme production by different species of Trichoderma fungus for lemon peel waste bioconversion

Extracellular enzyme production by different species of Trichoderma fungus for lemon peel waste bioconversion

Pembuatan Sabun Padat Antiseptik Ekstrak Etanol Kulit Jeruk Lemon (Citrus Limon (L.) Burm. F.)

Lemon peel waste (Citrus limon (L.) Burm.F.) contains secondary metabolites that function as antibacterials, such as alkaloids, flavonoids, and triterpenoids. This study aims to determine the formulation of antiseptic solid soap and the antibacterial activity of the ethanolic extract of the lemon peel by the diffusion method. The results showed the best formula for making antiseptic solid soap with ethanolic extract of lemon peel based on the requirements of SNI 06-4085-1996 was at a concentration of F3 (15%), homogeneous, had a pH of 8.54-9.82, foam height was around 3.5-4.7 cm, and a strong inhibition zone of about 12.48 mm. The conclusion of this study is that lemon peel has antibacterial properties that can kill the growth of Staphylococcus aureus bacteria.

Biodegradable film based on lemon peel powder containing xanthan gum and TiO2–Ag nanoparticles: Investigation of physicochemical and antibacterial properties

The aim of this study was to prepare a biodegradable film of sour lemon peel waste. The film of lemon peel powder (LPP) was modified with xanthan gum (XG) and TiO2–Ag nanoparticles (LPP/XG/TiO2–Ag). For this purpose, a central composite design was used to investigate the effect of xanthan gum and TiO2–Ag nanoparticles on the physicochemical and structural properties of the produced film. The results showed that the addition of xanthan gum led to an increase in thickness, moisture and index a of the samples and on the other hand a decrease in moisture and index a was observed with the addition of TiO2–Ag. With increasing xanthan gum, index b decreased slightly and with increasing TiO2–Ag, the amount of yellowness increased. With the addition of gum and nanoparticles, the antioxidant properties were slightly increased. With the addition of xanthan gum and TiO2–Ag, tensile strength and Young's modulus of the film significantly increased and the solubility and WVP decreased (P < 0.05). The FT-IR results showed the electrostatic interaction between lemon peel powder, TiO2–Ag and gum. In the SEM images, films containing TiO2–Ag and gum showed a homogeneous film with a granular state. According to the TGA results, the film samples containing gum and TiO2–Ag had better thermal stability than the control sample. The XRD results showed that adding TiO2–Ag and XG to the films reduced crystalline properties of film. Also, the results of antimicrobial activity against E. coli and Staphylococcus aureus showed that XG and TiO2–Ag increased antibacterial activity of film.

Assessment of the combined effects of beef cattle manure and lemon peel waste on soil-plant biochemical properties and phosphorus uptake by ryegrass

Agroindustrial waste-derived amendments may be used as substitutes for synthetic fertilizers to improve soil physicochemical and biological properties and crop production. Microbial activity plays an essential role in the beneficial effects of organic amendments on soil quality. In this study, we investigated the combined effects of two different agroindustrially-derived amendments, namely, beef cattle manure (CM) and lemon peel (LP), on soil biological properties, plant nutrition and antioxidant responses in ryegrass to evaluate their putative use as organic phosphorus fertilizers. A combined amendment of CM + LP was more effective than each amendment used separately. For example, the microbial biomass in the CM + LP group was more than 4 times that of the control. This can be largely attributed to the fungal community because the richness biodiversity index was greater than that of the bacterial and fungal biomass. The bacterial biodiversity index of the treated soils was lower than that of the control but was less dominant and more changeable with soil chemical parameters such as Al content and pH. Interestingly, ryegrass yield and phosphorus uptake significantly increased with the addition of combined CM + LP (43% and 44%, respectively) with respect to treatments with synthetic supertriple phosphate fertilizer (STP). Less oxidative stress was observed in treatments with CM + LP supplementation than in treatments with supertriple phosphate fertilizer. In conclusion, the combined application of CM + LP showed a beneficial effect on P uptake and oxidative stress with a concomitant increase in plant productivity, indicating that the combined amendment could be used as an organic fertilizer to improve the soil fertility and sustainability of agricultural production systems.

Changes in physico-chemical properties during composting of three common household organic solid wastes amended with garden soil

Composting is the most convenient and effective treatment of solid organic waste. In the present study composting of lemon peels, mixed vegetable waste and cooked food waste amended with garden soil was carried out. The thermophilic phase was reached by 21 days in all the composts mixture, with a range of 42 to 49 °C. The temperature in the cooked food waste mixture could not decrease to ambient temperature at the end of 90 days while lemon peel and mixed vegetable waste decreased to ambient temperature. The organic C, total N, available P and K declined from initial till the final stage in the lemon peel and mixed vegetable waste composting, while total N increased at final phase in the cooked food waste composting. The significant correlation of organic C with total N, available P and K in the composting process could be the reason for the declining trend. The amendment of garden soil leads to a lower thermophilic phase and a prolonged composting period. However, the quality of the composts were within the recommended ranges showing composting of these common household waste can be done at home successfully by adding the most easily available material garden soil using box method.

Hydrothermal Carbonization of Lemon Peel Waste: Preliminary Results on the Effects of Temperature during Process Water Recirculation

Hydrothermal carbonization (HTC) is a promising thermochemical pre-treatment to convert waste biomass into solid biofuels. However, the process yields large amounts of organic process water (PW), which must be properly disposed of or reused. In this study, the PW produced from the hydrothermal carbonization of lemon peel waste (LP) was recycled into HTC process of LP with the aim of maximize energy recovery from the aqueous phase while saving water resources and mitigating the overall environmental impact of the process. The effects of HTC temperature on the properties of solid and liquid products were investigated during PW recirculation. Experiments were carried out at three different operating temperatures (180, 220, 250 °C), fixed residence times of 60 min, and solid to liquid load of 20 wt%, on a dry basis. Hydrochars were characterized in terms of proximate analysis and higher heating values while liquid phases were analyzed in terms of pH and total organic carbon content (TOC). PW recirculation led to a solid mass yield increase and the effect was more pronounced at lower HTC temperature. The increase of solid mass yield, after recirculation steps (maximum increase of about 6% at 180 °C), also led to a significant energy yield enhancement. Results showed that PW recirculation is a viable strategy for a reduction of water consumption and further carbon recovery; moreover preliminary results encourage for an in-depth analysis of the effects of the PW recirculation for different biomasses and at various operating conditions.

Valorization of lemon peel waste as biosorbent for the simultaneous removal of nickel and cadmium from industrial effluents

The valorization of agricultural waste as biosorbent requires studies dealing with aqueous systems containing coexisting heavy metals. Batch adsorption experiments were carried out to study the competitive biosorption of Ni(II) and Cd(II) on alkali-modified lemon peel. The biosorption kinetic analysis indicated that the uptake of Ni(II) on lemon peel was better described by pseudo first-order model whereas for Cd(II) results were no conclusive. A rapid uptake of both metals on alkali-modified lemon peel was detected during the first 10 min obtaining more than 90% of the maximum sorption. The maximum adsorption capacity of Ni(II) and Cd(II) for single metal systems at optimum conditions (pH = 5, S/L = 5 g L−1, 25 ∘̲C), which were obtained from Langmuir model, reached as high as about 0.626 and 0.726 mmol g−1, respectively. These values were reduced 30 and 20 % in the presence of 100 mg L−1 of Cd and Ni, respectively. Regarding the reusability of the biosorbent, after five consecutives adsorption–desorption cycles using HNO3 and H2SO4 as desorption reagents percentages of 90 and 70 % were recovered for Ni and Cd. The promising results obtained through this work are expected to promote the use of lemon peel as an efficient biosorbent for industrial applications.

The preliminary study of oil removal using lemon peel waste

While the discovery of oil contributes a lot towards a country’s economy and technological development, it is also the cause for oil pollution. As such, this study proposes to use lemon peel waste as a low-cost adsorbent to manage oil pollution. For the untreated adsorbent, the lemon peels were cut into small pieces and dried under sunlight for 48 hours. Then, it was further dried in an oven for 24 hours and ground into powder. For the treated adsorbent, the lemon peels were soaked in 0.5 M of sodium hydroxide (NaOH) solution. The adsorbent was used to adsorb different types of oil (diesel oil, lubricant oil, waste vegetable oil) and in different types of water (ocean water, lake water, tap water) with different amounts of adsorbent which is 0.2 g, 0.4 g, 0.6 g, 0.8 g, and 1.0 g for adsorbent dosage experiment. While for types of water experiment, a ratio for volume of water and oil of 3:1, and constant mass adsorbent was used. The result showed that untreated adsorbent can adsorb higher amount of oils than treated adsorbent. The oil that could be easily adsorbed using lemon peels adsorbent is diesel oil with 89.91% adsorption. For the types of water, the result changes according to different types of water and oil used. It was found that the higher the mass adsorbent, the lower the percentage of oil removal. The highest percentage of diesel oil removed in ocean water is 81.68%. While the removal of lubricant oil and waste vegetable oil in lake water is 66.6% and 72.13%, respectively. Scanning Electron Microscopy (SEM) shows that treated lemon peels had small pores compared to untreated lemon peel waste. This study demonstrated and proposed that the lemon peel waste has a good potential in low-cost oil waste removal.