Tea Waste Research Articles

H2 rich gas production from agricultural waste mixture over Ni/kaolin and Ni/bentonite catalyst by gasification

Biomass gasification is an attractive technology in order to utilize agricultural waste which is the mixture of oil extracted sunflower seeds (pulp), tea, and tobacco waste. In this study, natural clay-based catalysts were synthesized using the impregnation method with the different Ni loading amounts (10, 20, 30 wt%), different support materials (kaolin and bentonite). The catalysts were characterized by Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), X-ray fluorescence (XRF), Scanning electron microscopy (SEM), and Brunauer–Emmett–Teller analysis (BET). Gasification of biomass mixture was performed using air as the gasification agent using an updraft tubular gasifier. Studies were carried out at 650–850 °C and the time range of 15–30 min without a catalyst, and the studies with catalyst were carried out at a constant temperature of 650 °C. The highest hydrogen yield was obtained as 6.86 mol/kg biomass at 650 °C, 15 min with 30% Ni/Calcined Kaolin.

Recycling of solid waste biosorbents for removal of nitrates from contaminated water

The presence of pollutants in aqueous solution, particularly from hazardous heavy metals and metalloids, is an important environmental and social problem. Nitrate is an inorganic compound that occurs under a variety of conditions in the environment, both naturally and synthetically. Nitrate in groundwater originates primarily from the fertilizers, septic systems and manure storage or spreading operations. Nitrate is one of the most serious water contaminants in the rural areas. Biosorption is a simple, economical and environment-friendly method for removal of nitrates from water. Every biosorbent had different physical, chemical and biological properties for nitrates removal from water. In our research work five different biosorbents (orange peels, tea waste, coconut wire, banana peels and maize) are prepared in the laboratory. The removal (percentages) of nitrate by applying the biosorbents (in nitrate contaminated water), orange peels is 100% at 2 gm, maize is 75% at 5 gm, banana peels is 100% at 5 gm, tea waste is 100% at 3 gm and coconut wire is 100% at 3 gm. The removal of nitrate over various biosorbents was as following orders: Orange peels > Tea waste ≈ Coconut wire > Banana peels > Maize. The orange peels biosorbent show that the best performance for nitrate removal from water. In the optimization process over orange peels biosorbents observed that the optimum pH is 6, optimum dosage is 1.9 gm, contact time is 60 min, temperature is 30 °C and agitation speed is 60 rpm. In the SEM and XRD characterization observed that the particle size and crystallite size of orange peels biosorbent was 2.34 µm and 3.02 nm, respectively with the end-centered cubic structures. In FTIR analysis over orange peels biosorbents observed that the OH, CH, alkynes with –C=C- stretch, carbonyls, amines and aromatics group peaks are presence. In the BET characterization observed that orange peels biosorbents has a higher surface area (45.42m2/g) and pore volume (0.512cm3/g) as compared to other biosorbents. The orange peels biosorbents represents heterogeneous surface with non-uniform distribution of heat adsorption and the adsorption process is multilayer. In the regeneration process observed that the reusing of orange peels biosorbent continuous three times the adsorption capacity of nitrates from contaminated water decreased from 100 to 93.32%. The purpose of this research is to optimize the use of orange peels biosorbent in nitrates removal from water by the successive biosorption–desorption cycles in a fixed-bed column. This process can be made economical by regenerating and reusing of the biosorbent after removing of the nitrates.

Physico-Mechanical Properties of Industrial Tea Waste Reinforced Jute Unsaturated Polyester Composites

The industrial tea waste reinforced jute polyester composites (ITW-JPC) were prepared by hand lay-up method for six different wt% (0%, 3%, 6%, 9%, 12%, and 15%) at 115˚C temperature. The effect of industrial tea waste filler on mechanical, physical, structural, and thermal properties in jute polyester composites were evaluated. It is found that tensile strength and flexural strength improved continuously with increasing filler loading up to 9wt% but decreased at 12wt% due to weak interfacial bonding and irregular distribution of filler and matrix. The maximum value of elongation at break (%) and Rockwell hardness were found in 0wt% and 15wt% composites respectively. The hardness increases when the resistance of the materials to the deformation increases. It is seen that water absorption and soil degradation are enhanced for all composites with the accumulation of filler content and time. The structural examination and functional group identification were investigated by using Fourier Transformation Infrared (FTIR) analysis. Thermal analysis of ITW-JPC showed that thermal degradation of composites started almost at the same time and the degradation of composites was occurring in three stages. Surface morphology and interfacial properties such as internal cracks, and fiber pull-out were examined through scanning electron microscopic (SEM) analysis.

Valorization of CTC tea waste through kombucha production and insight into GC-MS based metabolomics

This research paper is aimed to deliver a novel approach to prepare a popular probiotic beverage i.e., kombucha from infusion of tea waste to valorize the by-product of tea industry. In this study, a GC-MS based approach in combination with preliminary in vitro biochemical analysis was used to investigate the metabolic profiles, especially the antioxidant compounds produced during the fermentation of waste tea infusion. Waste tea infusion was found to be rich in xanthosine, the precursor of caffeine while the fermented sample was seen to be rich in more bioactive secondary metabolites derived from the substrate compounds i.e., xanthosine and sucrose. In addition, GC-MS based metabolomics helped to propose biosynthesis pathways of the metabolome which suggest the later breakdown of xanthosine and other substrate components into microbial metabolites during fermentation process. These findings are expected to be useful for further studies on production of bioactive formulations from tea waste.

SUSTAINABLE ENERGY-EFFICIENT CONVERSION OF WASTE TEA LEAVES TO REDUCING SUGAR: OPTIMIZATION AND LIFE-CYCLE ENVIRONMENTAL IMPACT ASSESSMENT

Innovative protocols involving energy-proficient pretreatment of waste tea leaves (WTL) for preparation of cellulose and its subsequent photocatalytic hydrolysis (PH) for production of total reducing sugar (TRS) have been reported. The WTL was subjected to alkali pretreatment (60 °C, 1 h) followed by bleaching (employing peracetic acid, 65 °C, 2 h) in a quartz halogen irradiated batch reactor (QHIBR) for efficient separations of lignin and hemicellulose fractions to produce WTL derived cellulose fiber (WTLDCF; 94.5% cellulose). Consequent PH of WTLDCF in QHIBR using combination of Amberlyst-15 and nano-TiO2 catalysts was optimized (parameters: 40 min, 70 °C, 1:30 WTLDCF to water weight ratio and 5 wt. % catalyst concentration) employing Taguchi design that provided maximum 68.25% TRS yield. The QHIBR demonstrated faster hydrolysis and superior energy-efficiency over conventional reactor owing to quartz halogen irradiation. Life cycle assessment indicated an acceptable global warming potential of 2.215 kg CO2 equivalent; thus, establishing an energy-efficient environmentally sustainable WTL valorization process.

Production of Nutrient-Enriched Vermicompost from Aquatic Macrophytes Supplemented with Kitchen Waste: Assessment of Nutrient Changes, Phytotoxicity, and Earthworm Biodynamics

Vermicompost is an organic fertilizer rich in nutrients, beneficial microbes, and plant growth hormones that not only enhances the growth of crops but also contributes to the improvement in the physicochemical and biological properties of the soil. However, its lower nutrient content makes it less preferable among farmers and limits its applicability. Here, we investigate, for the first time, nutrient enrichment of vermicompost by supplementing the free-floating macrophyte biomass with cow manure and organic nutrient supplements (eggshell, bone meal, banana peel, and tea waste). Free-floating macrophytes are aquatic plants that are found suspended on the water surface, playing a significant role in the structural and functional aspects of aquatic ecosystems. However, uncontrolled proliferation of these macrophytes endangers these ecosystems, having both economic and ecological implications; therefore, they need to be managed. Results showed an enhanced total nitrogen (2.87%), total phosphorus (0.86%), total potassium (3.74%), and other nutrients in vermicompost amended with cow manure and nutrient supplements. Highest biomass gain (710–782 mg), growth rate (11.83–13.04 mg), and reproduction rate (3.34–3.75 cocoons per worm) was also observed, indicating that amending bulking agent and nutrient supplements not only enhance the nutrient content of the final product but also improve overall earthworm activity. The stability and maturity of vermicompost, as indicated by C/N (<20) and Germination Index (>80), indicates that vermicompost obtained is suitable for agricultural applications. The study concluded that amendment of cow manure and organic nutrient supplements results in producing mature and nutrient-enriched vermicompost suitable for sustainable agricultural production.

Solid Phase Extraction for the Determination of Methylene Blue Using Lignocellulosic Biosorbent in Aqueous Solutions.

The recent introduction of a large number of synthetic dyes, which are toxic, mutagenic, and carcinogenic, has made the situation worse by disrupting normal aquatic life. For this reason, the detection and removal of dyestuffs in wastewater become important. In this study, for the extraction of methylene blue, used as solid phase extraction adsorbent, lignocellulosic biosorbent of tea waste activated with ZnCl2 was prepared. The factors affecting its extraction were studied in detail. To determine the sensitivity and certainty of the solid phase extraction process; optimized to have an adsorbent amount (75mg), wash solvent (3mL water), loading volume (20mL), elution solvent methanol/acetic acid (80:20, v/v), and eluent volume (8mL). As a result of the optimization processes, rates ranging from 94.4% to 98.9% recovery were obtained in methylene blue extraction in aqueous solutions. According to the results obtained, this method can be extensively applied in the efficient removal of colored contaminants.

Screening, Extraction, and Quantification of Melatonin in Waste of Some Plants

Environmental pollution is one of the world's biggest problems, and plant waste is one of its causes. For this reason, we have tried in this work to take advantage of this waste and benefit from it instead of being one of the pollutants. Seven dry waste from different plants (bitter orange peels, pomegranate peels, bitter orange leaves, Ziziphus leaves, albizia leaves, waste of black tea, and zahidi date palm fibers) were tested as cheap source of melatonin )MLT), which is a very important indoleamine compound. Throughout the current study, this hormone was extracted from these plants’ waste (which are considered as environmental pollutants) by applying different modified methods, whereby melatonin was identified and quantified by the HPLC-fluorescence system at The National Center for Drug Control and Researches (NCD). The results indicated the presence of different concentrations of melatonin in this waste. Bitter orange peels are a rich source of this hormone (868.868 µg melatonin /gm dried peel) in comparison to the other tested waste, followed by the waste of black tea (164.333 µg melatonin /gm waste). The results also showed the presence of trace concentrations of melatonin in Ziziphus leaves and Zahid date palms’ fibers. This work provides a cheap source of MLT, it is a recycling method for plant waste.

Optimized removal of hexavalent chromium from water using spent tea leaves treated with ascorbic acid

Spent tea leaves were functionalized with ascorbic acid to obtain treated tea waste (t-TW) to encourage the adsorption of hexavalent chromium from water. The adsorption removal of Cr(VI) was systematically investigated as a function of four experimental factors: pH (2–12), initial Cr(VI) concentration (1–100 mg L−1), t-TW dosage (0–4 g L−1), and temperature (10–50 °C) by following a statistical experimental design. A central composite rotatable experimental design based on a response surface methodology was used to establish an empirical model that assessed the individual and combined effects of factors on adsorptive removal of Cr(VI). The model was experimentally verified and statistically validated then used to predict optimal adsorption removal of Cr(VI) from water. At optimized conditions, ≥ 99% of 1 mg L−1 Cr(VI) can be removed by 4 g L−1 t-TW at a pH of 9. The adsorptive mechanism was assessed by conducting kinetics and equilibrium studies. The adsorption of Cr(VI) by t-TW followed a pseudo-second-order kinetics model (k2 = 0.001 g mg−1 h−1) and could be described by Langmuir and Temkin isotherms, indicating monolayer adsorption and predominantly adsorbate-adsorbent interactions. The t-TW exhibited a competitive Cr(VI) adsorption capacity of 232.2 mg g−1 compared with the other low-cost adsorbents. These results support the utilization of tea waste for the removal of hazardous metal contaminants from aqueous systems.

Synthesis of tea waste/Fe3O4 magnetic composite (TWMC) for efficient adsorption of crystal violet dye: Isotherm, kinetic and thermodynamic studies

We report the synthesis and application of tea waste/Fe3O4 magnetic composite (TWMC) for adsorption of crystal violet (CV) dye from aqueous solution. The best conditions were determined for 98.7% removal of CV dye using an adsorbent dosage of 1.0 g L−1, contact time of 90 min, an initial dye concentration of 100 mg L−1, and an initial pH of 7 at 298 K. In correlation with the results of kinetic study, the pseudo- second-order model fit for this study. The isotherm data of equilibrium study fitted well to Langmuir isotherm model. The composite's highest adsorption capacity for CV dye was 333.33 mg g−1. CV adsorption onto TWMC was heat releasing and spontaneous process. Adsorption of CV dye from aqueous solutions on TWMC was significantly favored, according to the findings of thermodynamic study. CV dye was effectively removed from aqueous solution, according to a phytotoxicity investigation. The study shows application of waste to useful strategy to synthesize tea waste magnetic composite and its efficiency in removing toxic dye CV from aqueous system.

Comparative Analysis of the Feasibility of Oil PalmBiomass and Factory Tea Waste as Biosorbent for Copper Ions Removal from Wastewater

Numerous research have been conducted to produce low-cost biosorbents. Because of this, this study aims to analyse the feasibility of Oil Palm Biomass (OPB) and Factory Tea Waste (FTW) as the biosorbent for fixed-bed adsorption column system in removing copper ions from wastewater under two parameters: initial concentration and pH value. Both biosorbents were compared in their surface area, pore volume, width and diameter. They were then analysed regarding their isotherm behaviour. FTW is found to have a larger surface area, pore volume and pore width, while OPB has a larger pore diameter than FTW. Besides, OPB showed higher efficiency of copper ions removal at low initial concentrations (25 and 50 mg/L), but FTW was more effective for high initial concentrations (100, 150 and 200 mg/L). FTW was more favourable than OPB in acidic and alkaline conditions, but the copper ions removal efficiency was over 99% for both biosorbents when operating at pH 7 of solution. Furthermore, it was proven that both biosorbents showed a better fit to Langmuir Isotherm as the R2 for both showed the highest value. In conclusion, this study suggested that FTW provided better performance in copper ions removal than OPB.
 Keywords: copper ions removal; oil palm biomass; factory tea waste; fixed bed adsorption column

Preparation of magnetically responsive carbonized tea waste and its efficient adsorption of uranyl ions

Preparation of magnetically responsive carbonized tea waste and its efficient adsorption of uranyl ions

A comparative study of tea waste derived humic-like substances with lignite-derived humic substances on chemical composition, spectroscopic properties and biological activity.

Emerging demand for humic substances escalated the short supply of coal-related resources from which humic substances are extracted in large quantities for various applications. Production of humic-like substances from lignocellulosic waste materials similar in structural and functional properties to humic substances has gained interest recently. Tea waste is a by-product from tea manufacturing factories enriched in lignocellulose is used to extract two types of humic fractions. One fraction has purified humic-like acid (HLA), and the other has unpurified humic and fulvic acids called as humic-like substances (HLS). Elemental composition, spectroscopic (13C CPMAS NMR and FTIR) properties, and biological activity of tea waste derived humic-like substances (TWDHLS) were compared with commercially available humic acid (CHA) extracted from lignite. Elemental analysis and FTIR characterization showed slight differences between HLA and HLS, while NMR results revealed that both have similar carbon distribution and are abundant in cellulosic polysaccharides and lignin derivatives. The presence of more stable compounds in TWDHLS contribute to its recalcitrant nature. NMR spectra of CHA significantly varied with TWDHLS and were rich in aliphatic compounds. The biological activity of TWDHLS and CHA was studied at five different concentrations (0, 20, 40, 80, and 160mg L-1). The results show that soil application TWDHLS at 80mg L-1 concentration showed better results on the growth of tea nursery plants similar to CHA, contrasting to the variation in their structural properties. Our findings revealed that TWDHLS could be used not only as a potential plant biostimulant but also as a better substitute for humic substances.

Fabrication, characterization, and application of Pickering emulsion stabilized by tea (Camellia sinensis (L.) O. Kuntze) waste microcrystalline cellulose

A massive amount of tea waste was generated in tea processing. In order to fully utilize tea waste, tea waste microcrystalline cellulose (MCC) was used as stabilizer without any other treatment to fabricate Pickering emulsion. Emulsion was produced by high pressure homogenization and characterized in terms of physicochemical parameters, morphologies and stabilities. High MCC concentration, high pH, low oil-water ratio and low ionic strength were benefited for emulsion stability. Pickering emulsions stabilized by MCC were stable for 42 days with the MCC concentration of 1.00% and 2.00%, oil-water ratio of 1:9, pH of 7.0 and ionic strength of 0 mM. Encapsulation in Pickering emulsion stabilized by MCC enhanced the stability of lycopene against photodegradation and thermal degradation, and high concentration of MCC promoted protection. Lycopene loaded in Pickering emulsion showed high stability and bioaccessibility during simulated digestion in vitro. Tea waste MCC could be used to prepare low fat and low salt Pickering emulsions, and provided perspective on high value-added utilization of tea waste.

Feasibility study on the use of processed waste tea ash as cement replacement for sustainable concrete production

In this study, processed waste tea ash (PWTA) generated by the boiler combustion of processed solid waste tea was used as a cement replacement at weights of 0%, 10%, 20%, 30%, and 40%. The effect of PWTA on the concrete properties was examined using the slump, density, compressive strength, porosity, chloride penetration depth, and microstructure as well as the embodied carbon content of concrete. Further, the contribution of the pozzolanic effect of PWTA to concrete strength was quantitatively analyzed using strength indices. The results showed that the slump and density of concrete decreased with the addition of PWTA. The concrete specimens with 10% PWTA achieved a similar compressive strength to that of control concrete at 28 days and a 4.57% higher value at 90 days due to the continuous pozzolanic reaction of PWTA. Strength indices also showed that the pozzolanic effect of 10% PWTA positively contributed to concrete strength at 90 days with a P value of 14.09%, which was higher than the percentage amount of PWTA used in the mixture. Owing to the pozzolanic reaction, the porosity and chloride penetration depth of 10% PWTA concrete at 90 days are lower by 4.2% and 9.4%, respectively, compared to those of control concrete. With the addition of PWTA up to 10%, the embodied carbon and carbon dioxide intensity could be reduced by 8.32% and 7.85%, respectively, compared with those of control concrete. These results suggest that PWTA is a useful replacement for up to 10% cement, enabling the production of innovative building materials for sustainable environment, with strengths similar to that of Portland cement.

Effect of different organic wastes on biological properties of maize (Zea Mays Indendata) rhizosphere

This study was carried in order to determine the effects different various organic wastes (tobacco prodction waste, wheat straw, tea waste and hazelnut husk) under greenhause conditions on biological properties (microbial biomass C, basal soil respiration, dehydrogenase activity, urease activity and arlysulphatase activity) in clay-loam soil and rhizosphere (Zea mays indandata) soil of maize plant. The organic wastes were thoroughly mixed with the soil at a rate equivalent to 50 g kg-1 on air-dried weight basis. Experimental desing was randomized plot desing with there replications in greenhause. The moisture content in soil was mantained around 60 % of maximum water holding capacity by weighing the pots everday. Changes in the biological properties were determined in the soil and rhizosphere (Zea mays indendata) samples and root free soil taken in 15, 30, 45, 60, 75 and 90 days after the experiment was conducted. At the end of experiment, all organic waste added soil increased biological properties of soil in comparison with the control (P<0.01) at all experimental periods. Moreover, biological properties in rhizosphere soil were higher than in root free soil at all organic waste application (P<0.01). Increased of organic wastes on soil biological properties had different trend (P<0.01), the most increases in the biological properties in the soil treated with tea wastes and tobacco production waste with supplying of low initial C/N ratio compared to other organic wastes.

Characteristics of 21 Types of Tea Waste for Adsorbance of Ionic Dyes from Aqueous Solutions.

In this study, 21 tea types (six black, four green, three Oolong, two herb, and five medicinal) were used to remove ionic dye from wastewater, as they could be potential adsorbents for several ionic dyes without purification or activated treatment. The majority of the 21 teas could adsorb cationic (MB) and anionic (ORII) dyes, with greater suitability for cationic dyes, as well as BB54 and BR46. Black dye (KBla), a mixture of several dyes, was adsorbed to a high degree. The tea waste treatment resulted in chromaticity reduction of the dye solution and turbidity changes. Dye adsorption was greater at higher temperatures than lower ones, although the effect of temperature was not strong. The adsorptions fit the pseudo-second-order-model; therefore, they involved chemical adsorption. The tea waste had great potential for the adsorption of several types of dyes without purification or activated treatment, although the mechanisms are yet to be determined. Therefore, the physical properties and structural components of each tea type should be analyzed by comparing common or different features of tea types. Taken together, many types of tea that are consumed worldwide can be used for efficient adsorption of ionic dyes by application of the tea waste.

Development of chemometrics-based neurocomputing paradigm for simulation of manganese extraction using solid-phase tea waste

Development of chemometrics-based neurocomputing paradigm for simulation of manganese extraction using solid-phase tea waste

Saccharomyces cerevisiae and newly isolated Candida boidinii co-fermentation of industrial tea waste for improved bioethanol production

ABSTRACT Although bioethanol is a suitable alternative to fossil-based fuels, limited technologies or lack of microorganisms with a broad substrate spectrum are serious bottlenecks for lignocellulosic ethanol production. In this context, the current study aimed to optimize bioethanol production from industrial tea waste by applying co-fermentation strategy for the first time. For this purpose, newly isolated xylose fermenter Candida boidinii and Saccharomyces cerevisiae produced 12.1 g/L and 14.1 g/L bioethanol, respectively, when the yeasts were cultivated alone in 20% (w/v) dilute acid pretreated and enzymatically hydrolyzed industrial tea waste. Bioethanol production increased to 21.9 g/L, and 70% improvement was achieved when the co-fermentation strategy was applied under the same conditions. This study shows that co-fermentation of industrial tea waste is an economically viable choice for value-added bioethanol production.

Utilization of Tea Industrial Waste for Low-Grade Energy Recovery: Optimization of Liquid Oil Production and Its Characterization

Pyrolysis oil, produced from industrial as well as municipal solid wastes through pyrolysis, could be a viable renewable alternative fuel. In this study, abundantly available industrial tea wastes are used to produce liquid oil. Flash pyrolysis experiments on a fluidized bed reactor were performed to analyze pyrolysis characteristics. The study evaluated three important process parameters, that is, pyrolysis temperature (300–500°C), particle size (0.5–1.25 mm), and inert gas flow rate (1.5–2.25 m3/hr). The thermogravimetric analysis of the tea wastes demonstrated that the thermal pyrolysis is possible to produce pyrolysis liquid and value added chemicals. The flash pyrolysis experiment produces maximum of 46.3 wt% liquid oil at the temperature of 400°C, particle size of 1.0 mm, and the sweep flow rate of 1.75 m3/hr. The liquid products were analyzed for its physical and chemical characteristics using Fourier transform infrared spectroscopy (FTIR) and gas chromatography-mass spectroscopy (GC-MS). The heating value of the liquid products showed that it can be used as liquid fuels, and its elements can be used for various industrial applications.