Rice Husk Research Articles

Reducing Silica Levels in WTP PLTGU X Wastewater using Rice Husk Filter Membranes

During the water demineralization process, silica content is increased due to the failure of the chemical reagent. This shows the need to perform a blowdown action to reduce silica content in the water. Therefore, this research aimed to determine the effectiveness of silica reduction in the Water Treatment Plant (WTP) of PLTGU X by observing the permeate flux values relative to time and operating pressure variables, using ceramic membrane made from rice husk. To achieve the objective, ceramic membrane was made from rice husk additives, with a pore diameter of 365 nm and a surface area of 25 cm². The results showed that the composition ratio of clay, rice husk, and iron powder was 82.5%, 15%, and 2.5%, respectively. Furthermore, ceramic membrane with rice husk additives successfully reduced silica content from 1250 ppb to 890 ppb at a pressure of 1.5 bar and 90 minutes of operation and from 1250 ppb to 710 ppb at 2 bar and 90 minutes of operation. This suggested that wastewater could be processed again in the demineralization plant to produce demineralized water. The best membrane performance in the filtration process was achieved at 90 minutes with a pressure of 2 bar, which successfully reduced silica content by 43.2%, with a permeate flux of 3.44 L/m².

Optimizing wheat growth and zinc uptake with compost and rice husk in alkaline conditions

Optimizing wheat growth and zinc uptake with compost and rice husk in alkaline conditions

Synthesis of biogenic mesoporous silica nanoparticles from rice husks waste materials via sol–gel method

Synthesis of biogenic mesoporous silica nanoparticles from rice husks waste materials via sol–gel method

Sustainable soil and organic matter managements for reducing straw burning, greenhouse gas production and emission, and their influencing factors in Northwest India

ABSTRACT Rice-wheat cropping system in Northwest India has been established since green revolution starting in the 1960s, based on modern varieties of crops and sufficient supply of water and nutrients. However, due to decrease in water availability and intensive cropping, soil fertility and soil organic matter contents started to decline. Also, mismanagement (burning) of crop residue induces air pollution, affecting human health. To address the issue of burning straw, other sustainable straw management alternatives are being evaluated from agronomic viewpoint. As for mitigation of air pollution and greenhouse gas emissions from soil, crop residue can be converted to biochar for various applications. We conducted field and laboratory incubation experiments to investigate the effects of two kinds of biochar (made from rice husk and rice straw) on soil properties and greenhouse gas emissions from wheat fields. After two seasons of field experiments, soil total C were increased only by rice-husk biochar application as compared with no amendment, rice straw biochar and chemical fertilizers. Greenhouse gases (GHGs; CO2, CH4 and N2O) were sampled by chamber method, measured by gas chromatography, then calculated emissions as CO2eq using Global Warming Potentials (GWPs). We found CO2 emission as dominant among three gases in the field experiment, although this included root respiration, and were not significantly changed by biochar application, compared to the control (chemical fertilizer application only). The incubation experiment showed that N2O was dominant among the three gases and increased by biochar application as compared to the control, corresponding to 0.9 and 14% of GHGs increase by rice-husk and rice-straw biochar, respectively, while the latter was equivalent to 0.2% of total C from rice-straw biochar applied. Although wheat yield was not significantly increased, the co-benefit of reduction in crop residue burning by rice-husk biochar application and contribution to international efforts of GHG emission mitigation envisage for sustainable carbon neutrality in an agriculture system.

Impact of Rice Mill Wastewater on the Water Quality of River: A Case Study from Rajim, Chhattisgarh

The Mahanadi River, located in Chhattisgarh, is experiencing significant water pollution near Rajim, primarily due to wastewater discharged by rice mills. This wastewater contains harmful substances such as rice husks, dust, and chemicals, leading to the degradation of the river's water quality. The pollution not only affects the aquatic ecosystem but also poses health risks to local communities dependent on the river for drinking, irrigation, and other daily activities. To assess the extent of this pollution, key water quality parameters are analyzed, including temperature, electrical conductivity (EC), pH, alkalinity, total dissolved solids (TDS), total suspended solids (TSS), total solids (TS), total hardness, chemical oxygen demand (COD), and biological oxygen demand (BOD). These parameters help determine the level of contamination and its impact on both the river's ecosystem and the people living nearby, highlighting the need for effective wastewater treatment and pollution control measures.

Sustainable lightweight rice husk fiber‐reinforced polypropylene composites: Preparation, properties, and environmental benefits

Sustainable lightweight rice husk fiber‐reinforced polypropylene composites: Preparation, properties, and environmental benefits

Biochar-enhanced soil pH and nutrient retention in Sudan Savanna agricultural soils of Nigeria

This in-depth study explores the transformative effects of biochar incubation on key soil properties, emphasizing sulphate, phosphate, and chloride retention; soil pH alteration; and dissolved organic matter dynamics. Initial analyses of the soil used revealed a fertile soil environment with a slightly alkaline pH, moderate phosphorus availability, and a loam texture conducive to robust plant growth. Different biochar types (rice husk and corn cob) were accurately applied at four levels (0 t ha−1, 5 t ha−1, 10 t ha−1, and 20 t ha−1). The investigation into the soil pH alterations post-biochar incubation highlighted a dose-dependent relationship, revealing variations in acidity and alkalinity. There was an emphasis on sulphate, phosphate, and chloride retention, elucidating the intricate interplay between biochar feedstock, application rates, and soil conditions. The sulphate retention exhibited notable variations influenced by biochar type, with the corn cob biochar (0.16 mg kg−1) demonstrating distinct advantages over the rice husk biochar (0.11 mg kg−1). The phosphate retention showed a dose–response relationship, correlating with increased biochar application levels. Surprisingly, the chloride retention demonstrated a complex trend, with the highest retention observed at control levels (0 t ha−1 = 1.82 mg kg−1), challenging conventional expectations. The dissolved organic matter dynamics revealed consistent responses to biochar application levels, indicating its potential to influence nutrient cycling and microbial activity. This study contributes valuable insights into biochar’s role as a sustainable soil amendment, providing a foundation for tailored soil management practices that enhance nutrient availability and overall soil health.

Green Synthesis of Nano-Sized Multiflower-like Fe3O4@SiO2/L-Tryptophan from Natural Resources and Agricultural Waste: A Photo-Switchable Oxidation Catalyst.

This study presents a novel, eco-friendly, and cost-effective magnetic hybrid photocatalyst, Fe3O4@SiO2/L-tryptophan, synthesized through a scalable three-step green approach using natural and agricultural waste. The Fe3O4@SiO2/L-tryptophan nanoparticle features a core-shell structure with a high surface area (63.14 m2/g), strong visible-light absorption (λ > 448 nm), a narrow band gap (1.84 eV), and superparamagnetic properties (22 emu/g), enabling efficient separation and reusability. Characterization techniques (XRD, XPS, FT-IR, FE-SEM, HR-TEM, UV-vis DRS, TGA, BET, and EIS) confirmed its structural stability, charge separation, and interfacial charge transport. The photocatalyst achieved 82.1% oxidative desulfurization of dibenzothiophene (DBT) and high conversion rates for toluene (85%) and styrene (90%) under visible light using O2 as an oxidant. It retained over 85% activity after five cycles, demonstrating excellent durability. For the first time, all components are derived from natural sources: Fe3O4 from sorghum seed extract, SiO2 from rice husk, and L-tryptophan for enhanced light absorption and charge separation. This sustainable synthesis reduces chemical waste and energy consumption, setting a new benchmark for environmentally friendly photocatalysts.

Adsorption of heavy metals onto food wastes: a review

There has been an increase in the production of food waste materials worldwide due to rapid population growth. The ineffective and sometimes unscientific and ad hoc disposal of these food waste materials has led to environmental pollution. Studies have reported the occurrence of heavy metals in water resources poses serious health threats to the environment and human health. Heavy metals are documented to be recalcitrant to conventional water treatment facilities since they are non-biodegradable. The use of food waste-based adsorbents provides an alternative solution for the adsorption of heavy metals in water resources, with concomitant benefit of valorization of otherwise waste materials. Therefore, this study examined the applications of food waste-based adsorbents for the removal of heavy metal ions. The study adopted a literature-based approach which involved reviewing published papers from selected science databases. The results indicate that these bioadsorbents have great removal efficiencies for different heavy metals with, rice husks and sugarcane bagasse demonstrating special sorption properties, especially for chromium and lead metal ions, respectively. The adsorption data were mostly best described by the Langmuir and Freundlich isotherm models, suggesting a monolayer coverage with similar sites and a heterogeneous surface, respectively. Further, the kinetic studies indicated that the adsorption processes largely followed a pseudo second-order model, showing chemisorption-mediated rate-limiting steps. However, regardless of these encouraging results attained, the use of food waste-based adsorbents has limitations such as variation in the composition and the structure. This leads to inconsistencies in adsorption efficiencies, regenerations and reuse, and reduced removal capacities. There is also the possibility of leaching of heavy metals from the adsorbents which may in-turn cause secondary pollution. Sustainability investigations such as life cycle assessment, cost-benefit analysis, pilot-scale studies and optimization studies present areas for future research.

Heavy Metal Concentrations in Amaranthus dubius (Thellung 19123) Grown on Soil Mixed with Compost Manure in Makurdi, Benue State, Nigeria

This study investigated the heavy metal concentration in Amaranthus dubius grown on soil mixed with compost manure in Makurdi, Benue State. Two different composts used in this study were produced from rice husk and orange peel, while cow and goat dung were used as soil modifier. Top soil collected from study area was sieved through an array of sieves with different pore sizes which were arranged in descending order. Sand fraction was found to be 90 %, 7 % silt and 3 % clay. The compost, drained water and Amaranthus dubius plant were analyzed for the presence and concentration of heavy metal content using Atomic Absorption Spectrophotometer. The data obtained were subjected to statistical analysis ANOVA. The mean concentrations of heavy metals in Rice husk and Orange peel compost showed that Cadmium (0.017), Iron (9.867), Lead (0.228) mg/l were significantly different at 5% level of probability. The analysis of variance from the mean concentration of heavy metals in Amaranthus dubius and water drained showed that Cadmium, Iron, Lead and Zinc were statistically significant at 1% level of probability. The heavy metal concentration: Cadmium (0.042), Iron (3.25), Lead 0.449(), Zinc (0.811) mg/l in Amaranthus dubius treated with orange peels and rice husk compost are higher than the permissive limit which portend public health challenge.

Cleaner energy production by combined use of biomass plants and thermal plants: a novel approach for sustainable environment

Global research studies focus on cleaner bioenergy production by using biomass. Rice husk is one of the potential biomass resources for producing a significant amount of bioenergy. However, rice mills lack cogeneration facilities. Insufficient rice husk availability and accessibility data is another hindrance. As rice husk is abundant in rural areas and most of the rice mills are running on a small-scale budget, the establishment of new, highly equipped, expensive cogeneration facilities at all rice mills is not feasible. Instead, employing nearby sugar refineries and coal-fired thermal stations is cost-effective. Thus, this study examines the synergistic use of sugar refineries and thermal plants to produce rice husk-based cleaner energy. This study also proposes locations for new biomass-based power plants where sugar refineries/thermal stations cannot be utilized. The study focused on three major rice-producing states of India: Karnataka, Tamil Nadu, and Andhra Pradesh. 74 regions across three states were assessed. ArcGIS and multi-criteria-decision-making were used to analyze site suitability. Suitability values were tested for strength and reliability using sensitivity analysis. Analysis suggests the use of existing 44 sugar refineries and 7 coal-fired thermal stations for bioenergy generation. With this synergistic cleaner production technique, only 15 new rice husk-based power plants are required, and there is no need to construct at all rice mills. The rice husk from the study areas has the potential to produce bioenergy of about 466 MW. Thus, a 98.7% decrease in carbon emissions was seen when rice husk was utilized for cleaner bioenergy production instead of coal.

Smart biopolymer based on rice husk extracts and Pinhão failure applied as an interlayer for sliced mozzarella cheese

Smart biopolymer based on rice husk extracts and <i>Pinhão</i> failure applied as an interlayer for sliced mozzarella cheese

Advanced statistical optimization and performance evaluation of self‐compacting geopolymer concrete utilizing industrial by‐products

AbstractThis study optimizes self‐compacting geopolymer concrete (SCGC) by incorporating industrial by‐products, such as fly ash, ground‐granulated blast furnace slag, and rice husk ash (RHA), as sustainable alternatives to conventional binders. The SCGC mixtures were designed with varying binder compositions and activator solutions, and their fresh and hardened properties were systematically evaluated. Workability tests, including slump flow, J‐ring, and V‐funnel tests, were conducted to assess the flowability and stability, while compressive, tensile, and flexural strength tests were performed at 3, 7, and 28 days to evaluate the mechanical performance. Advanced statistical tools, including response surface methodology and analysis of variance, were employed to identify key influencing factors and develop predictive models. The results indicate that an optimal RHA replacement of 5%–10% combined with a silica‐rich activator solution significantly enhances the mechanical properties of SCGC, achieving a 28‐day compressive strength of 55.6 MPa while maintaining excellent workability. The statistical models demonstrated high accuracy in predicting performance trends, validating the experimental findings. This study provides a robust framework for optimizing SCGC mix designs and for advancing sustainable and high‐performance construction materials.

Corn Cob (Zea mays) and Rice (Oryza sativa l.) Hulls as Bio Pots an Alternative to Single-use Plastic Pots

Global plastic production has surged in recent decades, exacerbating the environmental crisis due to its persistent presence and slow degradation. This parallels the environmental challenge agricultural waste poses, often improperly disposed of. On the other hand, biodegradable pots offer a sustainable alternative to plastic pots by decomposing naturally in the soil, reducing waste, and promoting soil health. Thus, this research investigated the feasibility of repurposing agricultural waste such as corn cob and rice hulls into biodegradable alternatives to conventional plastic pots. This study aimed to determine the mechanical performance of biodegradable pots in terms of tensile strength, compressive strength, and compressive strength (peak force). Additionally, comparing its mechanical properties to commercially available pots in the market. A quantitative research approach was employed, utilizing experimental methodologies and the Kruskal-Wallis test to assess differences between the materials. The analysis revealed that the bio-pots exhibited a tensile strength within the 0.1 MPa to 0.3 MPa range. Furthermore, compressive strength demonstrated an average of 0.4 MPa with a maximum peak force of 2625.2 N. The Kruskal-Wallis test result revealed a P-value of (.392), indicating no statistically significant difference in tensile and compressive strength compared to commercially available plant pots. These findings collectively suggest that the fabricated bio-pots possess the potential to be viable alternatives. However, further research and development are necessary to optimize their properties and enhance their performance. Consequently, by utilizing agricultural byproducts, this research contributes to mitigating environmental impact and promoting sustainability in agriculture.

Preparation and Characterization of Cellulose Based Superabsorbent Hydrogel from Rice Husk Cross-Linked With Ethane-1, 2-Diamine Using a Microwave

Superabsorbent hydrogels are being increasingly used as soil conditioners to enhance soil water retention, reduce the rate of irrigation and improve plant growth during drought. In the present work, superabsorbent hydrogel was prepared from cellulose based material with ethylenediamine as the crosslinking agent and evaluates it impact as water reservoir on maize growing in greenhouse. The cellulose isolated from rice husk, which has a basis to modify and obtain carboxymethylcellulose (CMC) using sodium hydroxide (NaOH) and monochloroacetic acid (MCA). The superabsorbent hydrogel was characterized by fourier transform infrared (FTIR) and x-ray diffraction (XRD). The percentage swelling attained by optimum conditions of time, power and amount of cross-linker required for the production of most desirable, stable and high water absorptivity were investigated, the optimum swelling capacity was found to be 1175%. The control pot (no superabsorbent hydrogels) revealed a significant difference in plant growth parameter and growth yield parameters compared to the pots treated with superabsorbent hydrogels. Increase in hydrogel dose significantly affects the growth and yield parameter of the maize. The optimum were recorded at 5grams for the superabsorbent hydrogels.

Formulation optimization and synergistic effects of flocculation–solidification–vacuum preloading on sludge treatment

Rapid infrastructure development generates large volumes of high-water-content sludge, creating an urgent need for efficient recycling and management strategies. This study introduces the flocculation–solidification–vacuum preloading (FSVP) method to enhance dewatering efficiency and strength development, facilitating subsequent mechanical construction requirements. To enhance solidification and reduce cement consumption, the response surface method was used to determine the optimal composite curing agent, which consists of 53% cement, 32% rice husk ash, and 15% sodium silicate. Vacuum dewatering was applied to sludge samples treated with different flocculants and curing agents to assess their synergistic effects on soil improvement. The mixed flocculant of polyaluminum chloride and anionic polyacrylamide significantly increased the micropore content and compactness, with pore sizes primarily concentrated around 0.01 μm. While the flocculant facilitated efficient drainage, required unconfined compressive strength could only be achieved with the further addition of a curing agent. The optimal composite curing agent formulation induced hydration and pozzolanic reactions, filling larger pores with cementitious materials and enhancing soil strength. As a result, the vane shear strength reached 58 kPa and unconfined compressive strength reached 365 kPa at 7 days, further increasing to 586 kPa at 28 days.

Developing sustainable burnt clay bricks incorporating agro-industrial waste

The study addresses environmental pollution and waste disposal issues resulting from rapid industrialization by investigating the use of agro-industrial waste materials to improve the quality of burnt clay bricks. The research evaluated the effects of incorporating fly ash (FA), silica fume (SF), rice husk ash (RHA), and sugarcane bagasse ash (SBA) in proportions ranging from 2% to 8% into brick earth. Results showed that in the Hyderabad zone, the compressive strength increased by 28%, 31%, 16%, and 8% with the addition of 4% FA, 4% SF, 2% RHA, and 2% SBA, respectively. However, in the Kandhkot locality, compressive strength enhancements were noted at 24%, 36%, 23%, and 27%, respectively, with consistent raw material ratios. For long-term durability, water absorption and efflorescence tests were conducted, which showed a reduction because of the addition of these waste materials. In both locations, the brick dimensions remained within the allowed range. In conclusion, the results suggest that the construction sector has the potential to enhance the properties of bricks by employing these agro-industrial waste materials and promoting sustainable methods for controlling environmental factors.

Influence of Nano Rice Husk Ash on Geotechnical Properties of Black Cotton Soil

Influence of Nano Rice Husk Ash on Geotechnical Properties of Black Cotton Soil

The Effect of Planting Media and Liquid Organic Fertilizer Interval on the Growth and Yield of Chili Peppers

This study aims to determine the effect of planting media and the interval of application of liquid organic fertilizer of banana stems on the growth and yield of chili pepper plants (Capsicum frutescens L.). The study was conducted in the greenhouse of the Faculty of Agriculture, UTP Surakarta from December 2024 to February 2025 using a factorial complete randomized block design (RAKL) with two factors: planting media (soil, soil + manure, soil + manure + rice husks) and the interval of application of liquid organic fertilizer (without liquid organic fertilizer, once every 5 days, once every 10 days, once every 15 days). The results showed that the planting media of soil + manure + rice husks (M2) had a very significant effect on plant height, fresh weight, dry weight, number of fruits, and harvested fruit weight, with the highest results in plant height (74.729 cm), fresh weight (76.688 g), and harvested fruit weight (576.75 g). The 15-day liquid organic fertilizer application interval (P3) also showed a significant effect on plant growth and yield, with the highest plant height (67.336 cm) and the highest harvest fruit weight (524.56 g). The conclusion of this study is that the use of a mixture of soil, manure, and rice husks as a planting medium and a 15-day POC application interval is the best combination to increase the growth and yield of chili pepper. This study also shows that banana stem liquid organic fertilizer can be an alternative environmentally friendly and sustainable organic fertilizer.

Emerging micro-contaminant adsorption from water and wastewater using CNT-doped biochar nanocomposites from rice husks and sewage sludge

Abstract In this study, rice husks (RH) and sewage sludge (SS) were used as feedstock to produce carbon nanotube (CNT)-doped biochar nanocomposites at two pyrolytic temperatures, 400 °C and 600 °C. The samples were produced, physicochemically and structurally evaluated, and tested as adsorbents for the extraction of six organic micro-contaminants of emerging concern (EMCs) in as-close-to-realistic concentrations, from water and wastewater. RH biochar nanocomposites were more effective than SS biochar nanocomposites on the adsorption of EMCs, requiring lower adsorption times (5 min as compared to 10 min) to sufficiently remove (&gt; 80%) the investigated pollutants. This was in agreement with the physicochemical analysis of biochar nanocomposites which showed a more developed porous structure for RH samples. The dominant mechanisms in the adsorption process were proven to be π-π EDA interactions accompanied by pore-filling mechanisms, along with hydrophobic and electrostatic interactions, in a less dominant role. This study showed that RH and SS biochar nanocomposites have the potential to be effectively used to decontaminate water and wastewater from emerging pollutants.