Leaf Waste Research Articles

Olive Leaf Waste Management

Olive trees are the oldest known cultivated trees in the world and present-day cultivation is widespread, with an estimated magnitude of 9 million hectares worldwide. As the olive oil industry has continued to grow, so has the environmental impact of olive oil production, such as the energy and water consumption, gas emissions and waste generation. The largest contributor to waste generation are the olive leaves, an abundant and unavoidable byproduct of olive-oil production due to the necessity of tree-pruning. It is estimated that an annual 1.25 million tons of olive leaf waste are generated in Spain alone, around 50% of the total world production. The leaves are currently used for biomass production or animal feed. However, because of their polyphenolic composition, olive leaves have potential in numerous other applications. In this review we analyze the chemical composition of olive leaves, and discuss current processing methods of the olive leaf waste, including thermochemical, biochemical, drying, extraction and condensation methods. We also examine current applications of the treated olive leaves in sectors relating to cattle feed, fertilizers, novel materials, energy generation, and food and pharmaceutical products. The aim of this review is to provide a resource for producers, policy makers, innovators and industry in shaping environmentally sustainable decisions for how olive leaf waste can be utilized and optimized.

Effect of pyrolysis operating conditions on the biomass shrinkage process of leaf waste and the formation of oxygenate and non-oxygenate compound products in bio-oil using ZSM-5 and YSZ catalysts

Leaf waste can be converted into more useful products by using several processes, one of which is using a pyrolysis process. Pyrolysis process can be carried out by requiring several parameters, namely raw material, temperature, residence time, and also the rate of heating. In the pyrolysis, biomass undergoes a shrinkage process. In this study, the variables used are temperature, gas flow rate, and catalyst combination ratio with the aim of seeing the relationship of these variables with the shrinkage process and the resulting pyrolysis product. The pyrolysis process produces products in the form of liquid, gas, and solid products. The liquid product formed was analyzed using the Gas Chromatography-Mass Spectroscopy (GC-MS) tool and it was found that the liquid product contained oxygenate and non-oxygenate in it. Oxygenate and non-oxygenate content in liquid products is increased by using ZSM-5 catalysts (Zeolite Socony Mobil-5) and YSZ (Yttria Stabilized Zirconia). ZSM-5 serves as an acid catalyst that can increase the hydrocarbon content and YSZ serves to increase the production of non-oxygenate in the resulting bio-oil product. Distribution products produced by catalytic processes have a more diverse distribution of products. The addition of catalysts also reduced the activation energy used by 5.41%.

Design and Prototype of Electric Smart Stove

The prototype of the electric smart stove is an electric stove with briquette fuel from teak leaf waste. The thermoelectric module used is 12 units of a Peltier TEC-12706. Thermoelectric generators take advantage of the Seebeck effect with temperature differences from both sides of the Peltier will produce electrical energy. The developing prototype method of an electric smart stove is carried out in 4 stages. First stage, analyzing geometry requirements and smart stove shape. Second stage is the process making of an electric smart stove. Third stage, installation of a power plant. The fourth stage, measurement of electrical power output. Based on the experiment, it is found that the thermoelectric generator produces 1.31 volts of electrical energy with a delta T of 40 degrees Celsius. As the result, an electric smart stove has not been able to charge the battery because the electric energy produced tends to be small.

Analysis of wastes height reduction, macrobiology and microbiology colony (fecal coli) on dry leaves composting process

The scattered leaf wastes can be turned into high nutrition organic fertilizer by utilizing vermicomposting methods. The wastes will be consumed by earthworms reducing the mass of the waste and the excrement can be used as vermicompost. One of the important things regarding the potential of earthworms in vermicomposting is the consumption rate or the decrease in the waste pile heights. Also, the number of microorganism colonies can be determined using the MPN (Most Probable Number) method based on the parameters of fecal coli bacteria in SNI 19-7030-2004. The vermicompost produced in this study comes from banyan leaves (Ficus benjamina) and bamboo leaves (Bambusa bambos). It takes 56 days for the vermicompost to ripen. The decrease in pile heights was measured every three days using a ruler and resulted in an average reduction of 2.18 cm/day for Ficus benjamina leaves and 1.0 cm/day for Bambusa bamboos leaves. Samples of microorganisms were taken on the 28th and 56th day and the MPN value was calculated. The MPN value obtained on the 28th day was 290 MPN/g and on the 56th day was 460 MPN/g, indicating that the colony had reached the predetermined quality standard.

Agricultural bamboo leaf waste as carbon precursor for the preparation of Cu-Al/biomass fiber adsorption and its application in the removal of ammonia nitrogen pollutants from domestic wastewater

Biomass derived from the plant waste in the environment has been recognized as a potential source for preparing adsorbent in recent years. In this context, abandoned bamboo leaves from the surrounding area were collected and used as carbon precursor to prepare novel adsorbent for ammonia nitrogen removal. Bamboo leaves were treated with alkaline solution to produce biomass fiber (BF), then BF was reacted with aluminum nitrate nonahydrate and copper(ii) nitrate hydrate to form a Cu-Al composite oxide layer on the surface. Samples were well characterized by SEM, XRD and BET technique. The influencing factors including the pH, temperature, the time, and the dosage of adsorbent on the adsorption of ammonia nitrogen were studied. It was found that the maximum adsorption capacity toward ammonia nitrogen was fitted out to be 18.29 mg/g from the Langmuir isotherms model. In addition, the adsorbent showed outstanding total ammonia nitrogen removal in actual domestic sewage (Total ammonia nitrogen, TN, 12.6 ∼ 16.2 mg/L), which is significantly higher than that of the commercial activated carbon. Kinetics and thermodynamics studies indicated that the synergistic adsorption effect between biomass material and metal oxide plays a dominate role in the adsorption process. Therefore, the proposed strategy provides a promising way to deal with ammonia nitrogen wastewater and other types of water pollution. Besides, the reuse of surrounding plant waste is also consistent with the concept of green chemistry.

Potential of essential oil of galam (Melaleuca cajuputi) leaf waste in Palangka Raya City

One of the causes of environmental and climate problems is human-generated waste such as Galam (Melaleuca cajuputi) leaf waste. Galam leaf waste with Essential oil ingredients can be a solution to the problem. The research objective was to utilize Galam Leaf waste in the form of essential ingredients and to determine the impact of climate change from the continuous utilization of Galam Plants The formula used was 10 liters of water, 4, 5, and 6 kg of Galam leaf biomass. Distillation activities carried out for 3 hours/formula. Repetition of each formula is done 5 times with the distillation technique. The essential oil results obtained from the formula of 4 kg of Galam leaf biomass are 4 ml, 6.2 ml, 12 ml, 7.5 ml, and 14 ml. Formula 2 is 11.5 ml, 16 ml, 14.5 ml, 13.5 ml and 15.5 ml. Formula 3 is 24.5 ml, 28 ml, 27 ml, 20.5 ml and 16 ml. Galam leaf waste processing activities can be a solution to reduce the impact of environmental and climate pollution.

Optimization of Fermentable Sugar Production from Pineapple Leaf Waste (Ananas comosus [L.] Merr) by Enzymatic Hydrolysis

Pineapple leaf waste is one agricultural waste that has high cellulose content. Pineapple leaf waste's complex structure contains a bundle of packed fiber that makes it hard to remove lignin and hemicellulose structure, so challenging to produce reducing sugar. Dried pineapple leaf waste pretreated with a grinder to break its complex structure. Delignification process using 2% w/v NaOH solution at 87oC for 60 minutes has been carried out to remove lignin and hemicellulose structure so reducing sugar could be produced. Delignified pineapple leaf waste has been enzymatic hydrolyzed using cellulase enzyme (6 mL, 7 mL, and 8 mL) to produce reducing sugar. The sample was incubated in an incubator shaker at 155 rpm at 45, 55, and 60oC for 72 hours. Determination of reducing sugar yield had been carried out using the Dubois method and HPLC. The model indicated that the optimum operating condition of enzymatic hydrolysis is 7 mL of cellulase enzyme at 55oC to produce 96,673 mg/L reducing sugar. This result indicated that the enzymatic hydrolysis operating condition improved the reducing sugar yield from pineapple leaf waste. The optimum reducing sugar yield can produce biofuel by the saccharification process.

Rubble BricQ (Briket Limbah Daun Karet) Sebagai Inovasi Bahan Bakar Alternatif Masa Kini

<p><strong>Rubber leaf waste is often found in rubber plantations and is considered of no value to the community. Rubble BricQ (Rubber Leaf Waste Briquettes) is an innovative alternative fuel today by utilizing rubber leaf waste that does not pollute the environment and the price is affordable. Briquettes can replace some of the uses of kerosene and LPG gas such as food processing, drying, burning, and heating. The purpose of this study was to find out how to make Rubble BricQ (Rubber Leaf Waste Briquettes) as an alternative fuel today which is packaged in video form due to the Covid-19 pandemic. This research phase begins by collecting the materials needed to make a Rubble BricQ (Rubber Leaf Waste Briquette) video through digital searches (internet). The result of this research is to know how to make Rubble BricQ (Rubber Leaf Waste Briquettes) as an alternative fuel today through video. Therefore, it can be concluded that Rubble BricQ is made by burning rubber leaf waste into charcoal, pounding it until smooth, adding tapioca flour, molding, drying it to dry, and the results can be used immediately.</strong></p><p><strong><em>Keywords</em></strong><em> - Briquettes, Rubber Leaves, Rubble BricQ.</em></p>

Removal of polycyclic aromatic hydrocarbons from water by magnetic activated carbon nanocomposite from green tea waste

This study aims to synthesize a magnetic activated carbon nanocomposite from green tea leaf waste (MNPs-GTAC) for evaluation of adsorption efficiency of 4 priority polycyclic aromatic hydrocarbons (PAHs). MNPs-GTAC contained spherically-shaped MNPs with cubic spinel structure, surface area at 118.8 m2/g, particle size at 8.6 nm and saturation magnetization at 34.2 emu/g. PAH adsorption reached a plateau at an MNPs-GTAC dose of 50 or 60 mg/L, pH of 2–4 and ionic strength of 0.1–10%, with PAH reduction in the presence of humic acid being compensated by addition of 0.1% sodium chloride. Kinetics was rapid attaining 80% removal within 5 min and the pseudo-second-order rate decreased in this order: Benzo[a]anthracene>Chrysene>Benzo[b]fluoranthene>Benzo[a]pyrene. Isotherm modeling revealed a Langmuir type-2 shape with the maximum adsorption capacity being 28.08, 22.75, 19.14 and 15.86 mg/g for Benzo[b]fluoranthene, Benzo[a]pyrene, Chrysene and Benzo[a]anthracene, respectively. Temperature study showed the PAH adsorption to be an endothermic and spontaneous process with increased randomness at solid-solution interface. Acetonitrile could completely recover the adsorbed PAH and MNPs-GTAC was successfully recycled 5 times with a minimum loss. Application to mineral water showed 86–98% and 72–89% removal for PAHs spiked respectively at 0.1 and 1 mg/L, while a complete removal was attained in tap and river waters.

Investigation on Synthesis of Hydrogel Starting from Vietnamese Pineapple Leaf Waste-Derived Carboxymethylcellulose.

Carboxymethyl cellulose (CMC) is obtained from Vietnamese pineapple leaf waste through etherification. By treating pineapple leaf powder with a solution of NaOH then with HNO3 at 90°C for an appropriate time, cellulose can be efficiently extracted. To obtain CMC, carboxymethylation was performed by reaction of the pineapple cellulose with chloroacetic acid at 60°C for 1.5 h. The optimal conditions for this reaction were established. The resulting CMC had a degree of substitution (DS) of 0.91. The hydrogel was prepared by graft copolymerization of acrylic acid and acrylamide to the synthesized CMC. During that reaction, N,N′methylenebisacrylamide (MBA) served as the crosslinking agent and ammonium persulfate (APS) as the initiator. The maximum hydrogel absorbencies for distilled water and 0.9 wt.% NaCl solution were relatively high, namely, 588.2 g/g and 79.3 g/g, respectively. Additionally, the water swelling and water retention behaviors of the hydrogel in soil were also investigated. The results showed that this hydrogel can be employed as a suitable moisture-holding additive in soil for cultivation purposes.

Utilization of Teak Leaf Waste as an Environmentally Friendly Dyes

As the second largest teak producer in the world, the abundance of teak leaf waste in Indonesia is inevitable. However, until now the effort to convert this material into functional products with high economic value is still very limited. In this study the potential utilization of teak leaf waste as an environmentally friendly dyeing material for the batik industry is examined. To be applied, extraction of teak leaves is carried out in a water solvent. Optimization of dyeing in cotton fibers is done by involving the use of positively charged alum mordant which can bridge the reaction between cotton fibers and antosianin in teak leaf extract which are both dominated by negative charges. The results showed the appearance of a light brown color on all cotton fibers, both fixed with iron (II) sulfate, alum and lime. However, the intensity of the color produced by each fixer varies in the range of 57.94% -84.62%. In line with this, the resulting fastness also varies on the staining scale 3 and 4. Dyeing with the highest intensity and fastness results from fixation using iron (II) sulfate. While alum and lime fixers tend to produce opposite intensities and fastness. This value shows the high potential of teak leaf waste material to be developed as a substitute for synthetic dyes with high toxicity in cotton fiber dyeing.

Thermo-kinetic study to elucidate the bioenergy potential of Maple Leaf Waste (MLW) by pyrolysis, TGA and kinetic modelling

The present study aims to evaluate the feasibility of Maple Leaf Waste (MLW) for the first time to produce biofuel-bioenergy and chemicals. It is meaningful to understand the thermochemical conversion and degradation pattern of the MLW to evaluate its biofuel-bioenergy potential. Different degradation stages and zones based on temperature and mass loss were identified to understand the pyrolytic behaviour in depth. Four different heating rates were used to conduct kinetic and thermodynamic analysis. The pyrolysis temperature was concluded ranged from 200 °C to 430 °C at all heating rates to obtain maximum bioenergy products. The kinetic parameters of pyrolysis were obtained by analysing through iso-conversional models of Kissinger-Akahira-Sunose (KAS), Friedman and Flynn–Wall–Ozawa (FWO). The average values of activation energies (75–91 kJ mol−1), high heating values (16.32 MJ kg−1), Gibb’s free energies (261–269 kJ mol−1) and change in enthalpy (68–85 kJ mol−1) have shown the significant potential for bioenergy production and suitability of co-pyrolysis with other waste and biomass feedstock.

KAMPUNG SABBETA’: DESA WISATA PENGELOLA ULAT SUTRA TERINTEGRASI DAN RAMAH LINGKUNGAN

Kampung Sabbeta' in Pising Village, Donri-donri District, Soppeng Regency, South Sulawesi is a silk development center that has several groups of silk craftsmen who actively produce silk threads. Even so, the productivity of community groups is very low. Their silk threads are still low in quality. Weaving skills are also very limited. In addition, the use of waste, especially mulberry leaves, has not been handled properly. The activities we carry out include the transfer of science and technology to increase community productivity, marketing strategies to improve product competitiveness, and ways of utilizing waste. The results of the transfer of knowledge and technology through FGDs, training, and practice in the field were greeted with high appreciation by the local community. Knowledge related to marketing, silk yarn spinning, eco-print and mushroom cultivation using mulberry leaf waste media has been provided. Especially for the development of eco-print on silk fabrics, they have been successful, their products have various kinds, and have even become one of the souvenirs from Sabbeta Village

Management of banana crop waste biomass using vermicomposting technology

This study reports the vermicomposting of banana crop waste biomass by Eisenia fetida. Cow dung has been used as bulking agent in this study. The experiment was conducted in six vermireactors containing different ratios of banana leaf waste biomass (BL) and cow dung (CD) for 105 days. Earthworm activity significantly reduced pH, TOC, C:N and C:P ratio of the wastes. Whereas macronutrients and micronutrients content increased after vermicomposting. TOC content of wastes reduced by 40–64% and C:N ratio of the vermicomposts was in the range of 8.9–24.3. The benefit ratio for heavy metals (Cu, Fe, Zn, Cd, Pb, Mn and Cr) was in the range of 0.23–3.44. The results indicated that the growth and fecundity of the earthworms was best in the vermireactors having 20–40% BL. Finally, it was concluded that vermicomposting can be included in the overall scheme of banana crop waste management.

Cellulose solvent–based pretreatment and enzymatic hydrolysis of pineapple leaf waste biomass for efficient release of glucose towards biofuel production

Leaf waste biomass of pineapple Ananas comosus can be used as the substrate for the second-generation biofuel production. The non-environmental friendly practice of pineapple leaf waste handling on the field can largely be avoided by directing the leaf waste as a feedstock for biofuels. In this study, three varieties of pineapple queen, simanchal (a local variety of India), and kew were used for the production of glucose. The leaf biomass of these pineapple varieties contained 19 to 22% extractives, 31 to 32% glucan, 17 to 22% hemicellulose, and 17 to 20% lignin. Biomass without any pre-treatment when digested with cellulase released 36 to 43% glucose, whereas glucose release percentages significantly elevated when the biomass was subjected to phosphoric acid-based cellulose solvent and organic solvent lignocellulose fractionation (COSLIF) pretreatment before hydrolysis. Herein, we found that cellulase enzyme dosages 5 filter paper unit (FPU) along with 10 international units (IU) of β-glucosidase per gram of glucan of COSLIF-pretreated leaf biomass of queen variety resulted in the generation of 84% glucose after 72 h of incubation. Assuming 100% conversion of glucose to ethanol, theoretical ethanol yield was calculated to be 212 L from 1 t dry leaf biomass.

The Effectiveness of Coffee Leather Organic Fertilizer on The Productivity of Red Spinach (Amaranthus Tricolor L.)

The study to determine the effect of variations in the composition of organic fertilizer from coffee husks on the productivity of red spinach (Amaranthus tricolor L), using a completely randomized design (CRD) with one control and four treatment combinations with six repetitions carried out for 30 days. Productivity includes the height and wet weight of red spinach. Data were analyzed using Multivariate Analysis of Variance (MANOVA). In conclusion, the application of coffee husk organic fertilizer has a significant effect on the growth and productivity of red spinach, the best dose of treatment is P3 = 50% coffee husk + 12.5% ​​leaf waste + 25% livestock manure + 12.5% ​​husk charcoal.

Implementasi Desentralisasi Composting melalui Pendampingan Pokdarwis Permata Pilang dalam pembuatan Kompos Organik dengan Memanfaatkan Limbah Kotoran Sapi di Pasar Hewan Wonoasih dan Sampah Daun Kering PT. Kutai Timber Indonesia Kota Probolinggo

Various ways and efforts to reduce waste continue to be carried out by multiple parties, especially in managing organic waste in Probolinggo. Through the Community Development approach, the result of this devotion can build multi-party synergy between the Probolinggo City Environment Office, Permata Pilang Tourism Awareness Group, Wonoasih Animal Market Manager, and PT. Kutai Timber Indonesia reduces cow dung's organic waste to organic compost through Permata Pilang organic compost house. Activities by accompanying Pokdarwis as the main driver in managing organic compost with the support of various parties have reduced cow dung waste from Wonoasih Animal Market by 12 Tons/month and dry leaf waste from PT. Kutai Timber Indonesia becomes an independent product of organic compost fertilizer to support agriculture in Probolinggo City. This assistance also impacts opening new jobs for Pokdarwis Permata Pilang youth with a turnover value of 9 million / month and building multi-party synergies to implement decentralized composting in Probolinggo City.

Pendampingan Pembuatan Pakan Ternak dari Limbah Pembungkus Lontong untuk Peningkatan Ekonomi Masyarakat di Kelurahan Kupang Krajan Kecamatan Sawahan Kota Surabaya

Banana leaf waste in kupang krajan village is very abundant. This becomes a problem of garbage buildup. Therefore, it is necessary to process waste in order to become a useful product. By using assed based community development (ABCD) method aims to provide training in making animal feed from banana leaf waste. The results of the training showed that the people of Kupang Krajan village were able to make quality animal feed with a fragrant aroma. Animal feed has also been tested to beef cattle, dairy cows, and goats in west Surabaya and Gresik. There are cattle that eat directly and some still have to adapt.

Ultrafine Ni-Based Nanomaterials on Hierarchically Porous Carbon from Biomass: An Efficient Bifunctional Electrocatalyst for Water Splitting

A highly efficiency bifunctional electrocatalyst, consisting of Ni/NiO nanoparticles decorated on biomass-derived hierarchically porous carbon (BHPC) was fabricated via one-step pyrolysis. Cauliflower leaf waste was used as a natural biomass carbon/nitrogen source for our cost-neutral BHPC. The catalytic activities of Ni/NiO/BHPC towards oxygen evolution reaction (OER) and hydrogen evolution reduction (HER) were investigated with variable pyrolysis temperatures ranging from 400 to 600 oC, which triggered changes in the crystallography and composition ratio between Ni and NiO in the resultant composite. For the optimal temperature of 500 oC, the resulting hybrid had 20.8 at.% Ni0, exhibiting modest Tafel slopes of 70 and 121 mV dec-1, while requiring 346 and 180 mV overpotentials to reach 10 mA cm-2 for OER and HER in 0.1 M KOH solution, respectively. When used for total water electrolyser, the Ni/NiO/BHPC electrodes achieved a current density of 10 mA cm-2 at 1.688 V only, and demonstrated superior cycling stability and rate capability over 20 h between 10 and 30 mA cm-2. The catalytic activity of the NiOx/BHPC-500||NiOx/BHPC-500 electrolyser is comparable to that of the recently reported cells assembled with Ni-based electrocatalysts. The excellent catalytic properties of the designed electrocatalyst are ascribed to the synergistic effect of Ni/NiO heterostructure and hierarchically porous carbon framework, which generates large electrochemical active surface area, numerous catalytic active sites and fast electron transport. This work provides strategies for the sustainable design of bifunctional electrocatalysts for efficient total water splitting. Keywords: hierarchically porous carbon, Ni/NiO heterostructure, biomass, water splitting

Effects of Various Drying Methods on Selected Physical and Antioxidant Properties of Extracts from Moringa oliefera Leaf Waste

This study aims to evaluate the effects of different drying methods on the physical properties, total phenolic content, total flavonoid content, and antioxidant activity of extracts from Moringa oliefera L. (MO) leaf waste. The effects of two drying techniques, namely, sun drying (A1) and tray drying (A2), on the physical and antioxidant properties of the extracts obtained using three extracting solvents, i.e., water (b1), ethanol (b2), and ethyl acetate (b3), were investigated. These extracts were analyzed for their physicochemical and antioxidant properties. The antioxidant properties were determined with the Folin Ciocalteau, aluminum chloride, and 1,1-diphenyl-2-picrylhydrazyl (DPPH) assays. Fourier transform infrared spectrophotometry (FTIR) was used to identify functional groups in the active compounds. It was found that the physical properties of the MO extract, including yield, pH, total solids, and color, showed significant differences for the two drying methods (p < 0.05). The b3 extract had the highest value for total phenolic contents, total flavonoid contents, and antioxidant activities, followed by b2 and b1, respectively, for both the sun drying and tray drying methods. There was a significant correlation between the total phenolic and flavonoid contents and antioxidant activity (IC50). This study reveals that waste material from MO leaves could be utilized as an antioxidant agent, which is expected to reduce environmental pollution from the MO processing industry.