Agricultural Waste By-product Research Articles

Competitive Effect of Zinc and Cadmium on the Biosorption of Chromium by Orange Waste

Batch experiments were conducted to test orange waste (OW), an agricultural solid waste byproduct from the orange juice manufacturing industry, as adsorbent for binary solutions of Cd2+-Cr3+ and Zn2+-Cr3+. Fourier transform infrared spectroscopy (FTIR) and the point of zero charge (pHpzc) were used to identify the functional groups on the OW surface involved in biosorption. The biosorption equilibrium data for both binary-metal solutions were obtained and fitted to various isotherm models. The extended Sips and the non-modified Redlich-Peterson isotherm models gave the best fit for the experimental data. According to the extended Sips model, the maximum biosorption capacity of OW was 0.573 mmol·g−1 for Cd2+, 0.453 mmol·g−1 for Zn2+, and 1.96 mmol·g−1 for Cr3+. The sorption capacity dropped to 0.061 mmol·g−1 for Cd2+ and to 0.101 mmol·g1 for Zn2+ in their binary systems with Cr3+ for the higher initial metal concentrations in the solution. However, the maximum sorption capacity of chromium was only slightly affected by the presence of Cd2+ or Zn2+. For both binary systems, the presence of a second metal ion in the solution always conduces to a reduction in the sorption of the other metal in the solution. The presence of Cr3+ decreased the sorption of Cd2+ and Zn2+ more than vice versa. Conclusively, effective removal of Cr3+ ions from an aqueous solution can still be achieved in the presence of Cd2+ or Zn2+.

Enhanced Goat Milk MUFA Quality via Date Pit Supplementation: A Time-Based Pattern Recognition Analysis Utilizing Agricultural Waste Byproduct.

Date pits are agricultural waste byproducts and are available in tons yearly. Milk MUFAs are lipids beneficial for health and sorted out for food product development. This work is aimed at researching the effect of supplementing dairy goats with date pit powder (DPP) as a source of fatty acids (FA), an alternative to enhancing the unsaturated FA in milk and analysed via chemometrics in a 3-month supplementation-based study. Saanen-Boer crossed dairy goats were divided into six groups comprising of control, 10 g and 20 g both for Ajwa DPP (high-quality dates) and Mariami DPP (agricultural waste byproduct), and another 30 g for Mariami DPP only. The supplementation exercise was done daily on each dairy goat. The DPP and milk samples were analysed for its FA profile applying GC-FID and followed by chemometric techniques, namely, PCA and PLS. Results indicated that the n-6/n-3 ratio was the highest for the unsupplemented group compared to the DPP-treated goats with lower n-6/n-3 ratios. The M30 group showcased the most promising health-related class of FAs viewed by 3D PCA and PLS model clustering patterns, in particular monounsaturated FA (MUFA) (C18:1n9c or oleic acid). These results suggest that Mariami DPP supplementation at higher doses and time to lactating Saanen-Boer cross goats can be a means to milk FA quantity and quality enhancement and that chemometrics via pattern recognition can be useful statistical tools when dealing with overwhelming data.

Effect of mechanical activation on the properties of rice husk ash-based one part geopolymer

Geopolymer concrete is an eco-friendly alternative to OPC because of its low carbon footprint. Being a “no cement” concrete, it is having great potential to offset the environmental impacts caused by ordinary Portland cement. The spectrum of uses for GPC is significantly influenced by the characteristics of the binder which should be rich in silica and alumina. Rice Husk Ash (RHA) is an agricultural waste byproduct obtained from the combustion of rice husk under controlled temperatures. Since it is produced in large quantities, the disposal of RHA is extremely difficult for waste management. This study examines how the mechanical activation of rice husk ash affects the physical, mechanical, and microstructural characteristics of one-part geopolymer concrete with rice husk ash. A mixture of rice husk, sodium hydroxide, sodium metasilicate, and aluminium oxide was ground in a ball mill for 2, 4, and 6 h to create one part geopolymer. XRD was used to characterize the powder. Workability was assessed using the slump test, and compressive strength was used to assess the mechanical property. Mechanical activation resulted in the creation of a more amorphous structure, according to XRD. For a six-hour ground sample, the greatest compressive strength of 32 MPa was attained.

Preparation of mesoporous activated carbon from novel African walnut shells (AWS) for deltamethrin removal: kinetics and equilibrium studies

Novel African walnut shell (AWS) was treated and improved as an agricultural waste by-product to produce high surface area activated carbon via chemical activation with potassium hydroxide (KOH) to achieve extremely effective adsorptive characteristics for deltamethrin removal. The adsorbent (KOHAWS) was characterized by scanning electron microscopy, Fourier transform infrared (FT-IR) spectroscopy, the Brunauer–Emmett–Teller surface area, and pH point of zero charge (PHPZC). Batch sorption experiments were investigated to study the effect of pH, initial concentration and contact time, sorbent dosage, and agitation speed. The results reveal that the experimental data fitted well with Langmuir isotherm model (R2 = 0.997) with maximum adsorption capacity at 57.64 mg g−1 and the kinetics of the sorption follows the pseudo-first-order model (R2 = 0.995). The sorption of deltamethrin onto KOHAWS reveals a high removal efficiency of 98.2%. The findings show that the novel AWS has excellent regeneration and reusability properties and may be used to remove pesticides from aqueous solutions instead of conventional activated carbon.

Synbiotic combination of prebiotic, cacao pod husk pectin and probiotic, Lactobacillus plantarum, improve the immunocompetence and growth of Litopenaeus vannamei

To reach the sustainable development goals on waste recycling, cacao pod husk (CPH), produced as an agricultural waste byproduct during the cacao bean processing was applied to manufacture CPH pectin for developing the potential for diverse application in aquaculture, minimizing CPH impact to the environment and bringing benefits to the agriculture and aquaculture industries. In this study, CPH pectin (5 g/kg diet) and Lactobacillus plantarum (LP; 1010 cfu/kg diet) were separately introduced to the diets of Litopenaeus vannamei for a 56-day feeding trial, and two synbiotic combinations of CPH pectin and LP (CPH pectin at 5 g/kg diet + LP at 107 cfu/kg diet or at 1010 cfu/kg diet) were also conducted. After the 56-day feeding trial, significantly elevated percent weight gain, percent length gains and feeding efficiency in L. vannamei were only observed in synbiotic combination of CPH pectin at 5 g/kg diet and LP at 107 cfu/kg diet treatment, and the remainder of the treatments remained consistently similar to the control. Significantly increases in total haemocyte count, granular cells, phenoloxidase activity, and respiratory bursts were observed in L. vannamei fed with synbiotics at 7–28 days of feeding, accompanied by significant promotion of phagocytic activity and clearance efficiency in response to V. alginolyticus challenge during 56 days of feeding trial. Furthermore, at the end of the 56 days of feeding trial, shrimp receiving CPH pectin and/or LP treatments showed a significantly higher survival ratio against V. alginolyticus infection and hypothermal stress. It was therefore concluded that CPH pectin or LP was confirmed as an immunostimulant for L. vannamei to trigger immunocompetence through oral administration without negative effects within 56 days of feeding trial, and the synbiotic combination of CPH pectin and LP exhibited complementary and synergistic effects on growth performance and immunocompetence in L. vannamei.

Corncob Derived Porous Carbon Anode for Long-Term Cycling in Low-Cost Lithium Storage

Abstract Corncob is a biomass waste that has the second cutting-edge abundance on a global scale. As a low cost and feasible agricultural waste byproduct, corncob can be used in the energy sector to produce green and cheap energy. In this research, we used corncob as a raw material to make corncob-derived carbon composites (CDCCs) through a scalable and cost-effective calcination process, without the need of acidic or alkali treatments under different conditions. The obtained CDCC possesses a large number of micropores and mesopores having a slit-like shape. It showed outstanding long-term cycling stability up to 4000 cycles, maintaining stable specific capacity of 230 mA h/g at a current density of 500 mA/g. The obtained composite anode showed outstanding performance at a current density of 1000 mA/g, with specific capacity of around 200 mA h/g up to 10,000 cycles. This method can also be applied to other biomass wastes for sustainable use in different applications.

Use of Pulsed Electric Field as a Low-Temperature and High-Performance “Green” Extraction Technique for the Recovery of High Added Value Compounds from Olive Leaves

Olive leaves (OLL), an agricultural waste by-product, are considered a significant bioresource of polyphenols, known as bioactive compounds. This study evaluates the pulsed electric field (PEF) technique for the extraction of polyphenols from OLL. The study parameters included a series of “green” solvents (ethanol, water as well as mixtures of them at a 25% step gradient) and different input values for the pulse duration of PEF. The phytochemical extraction degree was evaluated using total phenol concentration (Folin–Ciocalteu method) and high-performance liquid chromatography (HPLC) analyses, while the antioxidant activity was assessed using differential scanning calorimetry (DSC). The results obtained from the PEF extracts were compared with those of the extracts produced without the PEF application. The highest PEF effect was observed for aqueous ethanol, 25% v/v, using a pulse duration of 10 μs. The increase in the total polyphenols reached 31.85%, while the increase in the specific metabolites reached 265.67%. The recovery in polyphenols was found to depend on the solvent, the pulse duration of treatment and the structure of the metabolites extracted.

Adsorption Of Methylene Blue from Aqueous Solution with Sulfuric Acid Activated Corn Cobs: Equilibrium, Kinetics, and Thermodynamics Assessment

Three adsorbents with different characteristics were produced in this study by activation of sulfuric acid with different concentrations, from corn Zea mays L. cobs, which is an agricultural waste by-product resulting from harvesting. After characterization by the parameters such as Boehm titration, determination of pH-pHpzc, and methylene blue – iodine number, and IR analysis, their methylene blue adsorption potentials from aqueous medium were investigated based on equilibrium, kinetics, and thermodynamics evaluations. This study aims to examine the effects of relatively dilute and concentrated acids on the activation process and to gain an economic value to waste materials through the production of a new adsorbent. It was observed that the initial solution pH did not have a significant effect on the adsorption efficiency. The adsorption process reached the equilibrium at the end of the first 120 minutes, and the kinetic data fit the pseudo-second-order kinetic model. Langmuir adsorption capacity 295.5 mg/g of the adsorbent produced by activating with 50% sulfuric acid was found higher than those produced with 75% and 98% acids. An increase in ambient temperature effected the adsorption positively. As a result, in this study, very low-cost adsorbents were produced from the waste by-product corn cobs, and a new approach was proposed for cleaning wastewater containing dyestuffs.

Early Age Shrinkage Behavior of Triple Blend Concrete

The early age shrinkage is responsible for the early age cracking of concrete. It is very critical for durability of concrete. The change in volume of concrete due to evaporation of water or dehydration process is known as shrinkage. To reduce the early age shrinkage utilized the supplementary cementitious material (SCM) in concrete. In present research industrial and agricultural waste byproduct like fly ash (FA) and rice husk ash (RHA) along with cement were used as SCM. The triple blend concrete was prepared by the combination of 20%, 30% and 40% partial cement replacement with FA and RHA for 0.30, 0.35 and 0.40 water-cement ratio. The concrete samples were tested by advanced instrument as shrinkage cone meter were used for measure the shrinkage. The result shows that the early age shrinkage reduced with increasing the SCM content. The microstructure characteristics enhanced with raising the content of FA and RHA up to 30% replacement; that was due to the dense particle packing.

Ash based nanocomposites for photocatalytic degradation of textile dye pollutants: A review

Ash is a highly available industrial and agricultural waste by-product. Giving insights into the huge generation of ash and environmental concern of disposal issue, aesthetic attention has been drawn on the sustainable utilization of ash as a renewable supporting material in the synthesis of photocatalytic nanocomposites. Coal fly ash, rice husk ash and volcanic ash are currently being investigated for their potential to be applied as an effective precursor material for photocatalyst preparation, owing to their advantages of high adsorption capability, high ion-exchange capacity, significant specific surface area and high reusability. The novelty of these studies is that prepared ash based photocatalysts could provide a synergistic effect of the adsorption capacity of ash and the photocatalytic activity of photocatalysts to enhance the overall degradation efficiency of dye. Exploring the possible usage of these abundant by-products not only solving the environmental problem but also highlighting its further economic value of utilization with the concept of “waste to wealth”. This paper presents a fundamental information pertaining to the basic principles of photocatalysis and semiconductor based photocatalysts. A brief overview of the role of ash based nanocomposites in terms of the preparation methods and conditions, morphologies, physiochemical properties and their photocatalytic performances on the degradation of dye pollutants is highlighted. The optimization, mechanism and stability study are also reviewed. The finding showed that the porous structure and the presence of aluminosilicate in the ash greatly enhance the adsorption capacity of the total composite in the dye degradation process. The photocatalytic performance was dependent on the calcination temperature, catalyst loading, solution pH, initial dye concentration and light source. However, reusability test indicated the high stability of the prepared ash based composites, with most of the dye degradation efficiency greater than 80% even after a few successive regeneration cycles.

Waste environmental sources of metakaolin and corn cob ash for preparation and characterisation of green ceramic hollow fibre membrane (h-MCa) for oil-water separation

This study describes the preparation of green ceramic hollow fibre membranes derived from metakaolin (MK) and corn cob ash waste (CCA) as membrane support for water filtration and oil-water separation using phase inversion and sintering techniques. Pristine MK membrane is closely associated with its brittleness property and possesses low strength. In this study, a proportion of MK was substituted with corn cob ash (CCA), an agricultural waste by-product as pore forming agent material and sintering aid in preparing MK–corn cob ash hollow fibre membrane (h-MCa) for enhanced permeation and strength properties. MK:CCA ratio loadings at 35 wt % of powder were adjusted for fibres A-100:0, B-75:25, C-50:50, D-25:75, and E−0:100. The SEM image supported by EDSA revealed the high agglomeration of CCA–SiO2 particles coated with KCl, as the XRD analysis displayed mainly the crystal phases of KCl. The high content of CCA–KCl revealed its significant effect as body shaping and body forming in preform controlling the h-MCa suspension matrix structure. The viscosity of the suspension correlated with the dissolution of KCl in NMP suspension and MK–CCA fraction ratio to effectively function as a green enhancer and porogen towards the particle arrangement in the ceramic membrane matrix. The feasibility study showed that fibre B exhibited higher permeability (1359.93 L/m2h), oil/water removal efficiency (74.73%), and CCA maintained superior mechanical strength (41.61 MPa) at a significant low sintering temperature of 1200 °C, as the CCA possessed a great fluxing agent in the sintered membrane. Therefore, this study proved that green MK–CCA was effective, sustainable, and ecologically environmentally friendly for ceramic membrane support applications.

Powdered activated carbon prepared from Leucaena leucocephala biomass for cadmium removal in water purification process

Activated carbons (ACs) were prepared from Leucaena leucocephala biomass. This is an agricultural solid waste by-product, as well as easily grown species available abundantly in Southeast Asia. In this work, activated carbon derived from Leucaena leucocephala biomass was prepared for sequestration of cadmium from aqueous solutions. The activated carbon was produced by a NaOH chemical activation process using NaOH:char ratios (w/w) of 1:1, 2:1 and 3:1 at 800 °C. The activated carbon’s BET surface areas were determined as 185, 595, and 776 m2 g−1 for the NaOH:char ratios of 1:1, 2:1, and 3:1, respectively. At initial concentration of 30 mg/l, maximum cadmium adsorption was achieved within 40 min. The adsorbent also showed good sorption of cadmium at pH 7.0 with solution temperature of 30 °C. Isothermic studies showed the adsorption process best fitted to Langmuir isotherm which indicates monolayer adsorption had happened while kinetic studies showed physisorption process was favorable, determined by pseudo-first order kinetic model. Maximum adsorption capacity was found to be 70.423 mg/g for NaOH:char ratios of 3:1.

Removal of Phosphate from Wastewater Using Carbonized Filter Cake

The aim of this work was to study the potential of the agricultural waste byproduct as a low-cost adsorbent for removal of phosphate ion (PO43-) from synthetic wastewater. The simple preparation of carbonized filter cake (CFC) was performed at 550°C. CFC was also characterized using FTIR, X-ray fluorescence analysis. The adsorptive parameters of batch experiment, such as pH of solution, dosage and contact time were systematically studied in order to the optimization condition. The optimum conditions of pH, contact time and adsorbent dose were to be 6, 60 min, and 2 g/L, respectively. The Langmuir and Freundlich isotherms were used to calculate the adsorption parameters that was able to describe the equilibrium isotherm and adsorptive mechanism. The maximum monolayer adsorption capacity of CFC was estimated as 20.32 mg/g. The optimized condition was applied for phosphate removal from synthetic wastewater. The achieved phosphate removal efficiency from synthetic wastewater sample was to be 92.4%. Filter cake is a low-cost byproduct of sugar cane but it can also highly effective remove phosphate ion from aqueous solution. The modification of filter cake surface via chemical reaction as a new adsorbent in order to increase surface sites and high affinity with phosphate ion will also be further studied.

Preparation of activated carbon from doum stone and its application on adsorption of 60Co and 152+154Eu: Equilibrium, kinetic and thermodynamic studies

Removal of radionuclides from wastewater before discharging to environment is necessary for the safety of living beings. Activated carbon prepared from doum stone (DS), an agricultural waste by-product, has been used for the sorption of 60Co and 152+154Eu radionuclides from aqueous solutions. DS has been characterized by different analytical tools. The efficiency of the adsorbent was investigated using batch sorption technique under different experimental conditions. The equilibrium sorption data were analyzed using Freundlich and Langmuir isotherm models. The kinetic experimental data were analyzed using four kinetic models including pseudo-first order, pseudo-second order, Elovich and intraparticle diffusion model to examine the mechanism of sorption and potential rate-controlling step. The maximum capacity of DS was found to be 121 mg/g and 166 mg/g for cobalt and europium, respectively. Sorption efficiency of DS to remove 60Co, 152+154Eu and 134Cs from real radioactive wastewater and environmental (river water and sea water) samples was also investigated. The results revealed that the prepared DS as low cost could be used as a promising material for the simultaneous removal of different radionuclides such as 60Co, 152+154Eu and 134Cs, or trivalent actinides such as 241, 242m,243Am from real radioactive waste and environmental water samples.

Removal of Cr(VI) from Aqueous Solutions Using Buckwheat (Fagopyrum esculentum Moench) Hull through Adsorption–Reduction: Affecting Factors, Isotherm, and Mechanisms

Cr(VI) is a highly toxic pollutant and its contamination frequently occurs in aqueous environment. As an agricultural waste byproduct, buckwheat hull was used in this study as a low‐cost biomaterial to remove Cr(VI) from aqueous solutions. The biomass was characterized using scanning electron microscopy, X‐ray photoelectron spectroscopy (XPS), and Fourier transform infrared (FT‐IR) spectroscopy. The performance of buckwheat hull on Cr(VI) removal was investigated using the batch experiments. The effect of affecting factors, such as solution pH, initial concentration of Cr(VI), adsorbent dose, temperature, and contact time, were carefully examined. The obtained results revealed that pH had significant effect on Cr(VI) removal and the optimal pH was about 2.0. Increase of adsorbent dose was favorable to the increase of removal ratio, but it decreased the adsorption capacity. Among Langmuir, Freundlich, and Dubinin–Radushkevich models, the Langmuir model was found to best fit the adsorption isotherms of Cr(VI) on buckwheat hull. The maximum adsorption capacity at 45°C was 63.61 mg g−1. The thermodynamic parameters (ΔG°, ΔH°, and E) analysis indicated that the adsorption process was a spontaneous, endothermic and chemisorption process. In addition, XPS analysis revealed that the adsorbed Cr(VI) was partially reduced to Cr(III). FT‐IR spectra indicated that the carboxyl and amino groups were involved in chromium adsorption. From these results, the most probable mechanisms for removal of Cr(VI) using buckwheat hull were found to be electrostatic attraction, chemical reduction, and complex interaction.

Biotechnological Valorization of Cashew Apple: A Review

Cashew apple, the peduncle of cashew fruit, is an agricultural waste byproduct from harvesting cashew nuts. Cashew apple juice contains about 10% reducing sugar. Its bagasse contains about 20% of cellulose. The byproducts can be used as a substrate for several microbial fermentation processes. Wine and bioethanol were produced by Saccharomyces cerevisiae. Probiotic beverage and lactic acid were produced by Lactobacillus casei. Biosurfactants-rhamnolipids, emulsan and surfactin were synthesized by Pseudomonas aeruginosa, Acineto- bacter calcoaceticus and Bacillus subtilis, respectively. Tannase and pectinase were produced during solid-state fermentation of Aspergillus spp. Prebiotic oligosaccharides were synthesized by the activity of dextransucrase produced by Leuconostoc spp. Cashew apple is a potential substrate for producing a variety of products, depending on the type of microorganisms used.

Investigation of More Environmental Friendly Materials for Passive Cooling Application Based on Geopolymer

Evaporative passive cooling systems are considered as interesting technique to address the environmental and energy crises. Within this context, the development of new porous materials has attracted a lot of attention recently. The utilization of industrial and agricultural waste byproduct will also make this technology more environmentally friendly. This article reviews the application of byproduct, industrial wastes materials, and other agricultural residuals as raw materials for the preparation of geopolymers. It must also be taken into due consideration that many potential waste and residuals have not been extensively studied, and requires extensive investigations.

Adsorption of Chromium (VI) from Aqueous Solution by Agricultural Waste Derived Activated Carbon

Activated carbon prepared from grapefruit peel, an agricultural solid waste by-product, has been used for the adsorption of Cr(VI) from aqueous solution. The effects of adsorbent dosage, pH and temperature on adsorption of Cr(VI) were investigated. The maximum adsorption yield was obtained at the initial pH of 3. The dynamical data fit very well with the pseudo-second-order kinetic model and the calculated adsorption capacities (23.98, 24.33 and 24.81 mg/g) were in good agreement with experiment results at 20°C, 30°C and 40 °C for the 100 mg/L Cr(VI) solution. The Freundlich model (R2 values were 0.9198-0.9871) fitted adsorption data better than the Langmuir model. The calculated parameters confirmed the favorable adsorption of Cr(VI) on the activated carbon prepared from grapefruit peel.

Use of carbonised beet pulp carbon for removal of Remazol Turquoise Blue-G 133 from aqueous solution

Carbonised beet pulp (BPC) produced from agricultural solid waste by-product in sugar industry was used as adsorbent for the removal of Remazol Turquoise Blue-G 133 (RTB-G 133) dye in this study. The kinetics and equilibrium of sorption process were investigated with respect to pH, temperature and initial dye concentration. Adsorption studies with real textile wastewater were also performed. The results showed that adsorption was a strongly pH-dependent process, and optimum pH was determined as 1.0. The maximum dye adsorption capacity was obtained as 47.0 mg g(-1)at the temperature of 25 °C at this pH value. The Freundlich and Langmuir adsorption models were used for describing the adsorption equilibrium data of the dye, and isotherm constants were evaluated depending on sorption temperature. Equilibrium data of RTB-G 133 sorption fitted very well to the Freundlich isotherm. Mass transfer and kinetic models were applied to the experimental data to examine the mechanisms of adsorption and potential rate-controlling steps. It was found that both external mass transfer and intra-particle diffusion played an important role in the adsorption mechanisms of dye and adsorption kinetics followed the pseudo second-order type kinetic model. The thermodynamic analysis indicated that the sorption process was exothermic and spontaneous in nature.

Use of palm fronds as shaded cover for evaporation reduction to improve water storage efficiency

Water bodies in arid surroundings can be subject to high evaporation losses due to oasis effect. Evaporation raises the storage requirements of water bodies and lowers the yield. Covering of water bodies can help in reducing evaporation. The work presented in this study aims at investigating the use of palm fronds as shaded cover for the reduction of evaporation from the open water surface so as to increase the storage efficiency. The material used for cover was locally available palm fronds which are a massive agricultural waste and environmental friendly by-product in Saudi Arabia. Pan evaporimeters were used in the present study. One pan was covered like a shade made of palm fronds, which were tied up on mesh wiring while the other was kept without any cover. Initially a single layer of cover was used as shaded cover which was replaced by a cover of two layers of palm fronds in order to see the effect of thickness of cover on overall evaporation. It was observed that the average reduction in evaporation in the covered pan (with single layer of cover) was about 47% as compared to the evaporation from the open pan. However, the average reduction in evaporation in the covered pan (with double layer of cover) was about 58% as compared to the evaporation from the open pan.