Application of cellulase for the modification of corn stalk: leading to oil sorption

Effective multi-functional biosorbent derived from corn stalk pith for dyes and oils removal

In this study, malic acid-modified corn stalk pith (MA-CSP) was prepared as an environmentally friendly multi-functional bio-sorbent for adsorbing of dyes and oils. The sorption capacity of the MA-CSP for single and binary dyes is 328.46 mg/g - 566.27 mg/g. In addition, the MA-CSP also had good sorption for lubricating oil, soybean oil, diesel oil, and isopropyl alcohol, which were 37.2 g/g, 44.1 g/g, 33.8 g/g, and 29.3 g/g, respectively. Physical and statistical models were used to analyze the adsorption behavior of methylene blue (MB) and crystal violet (CV). And its sorption behavior for dyes was also affected by the co-existing salts in water. The sorption mechanism of the dye was mainly electrostatic attraction and hydrogen bonding action. The sorption of oil was primarily via the role of van der Waals force and hydrophobic interaction. The MA-CSP, as an eco-friendly, economical and efficient multi-functional sorbent, holds promise for effective dyes and oil removal from contaminated water, and its application in other fields is also highly anticipated.

Sorption as a rapidly response for oil spill accidents: A material and mechanistic approach

Accidents involving oil transportation has increase due to directly connection with the elevation of global energy demand. The environmental losses are tremendous and brings huge economic issues to remediate the spilled oil. This report presents an up-to-date review on an overall aspects of oil spill remediation techniques, the fundamentals and advantages of sorption, the most applied materials through diverse types of oil spill sites and oils with variety features, highlight to natural materials and future prospective. As the environment preservation progressively becomes a major social concern issue, the achievement of a worldwide distribution process aligned with environmental legislation and economic viability is crucial to the oil industry. For this, a specific preparation considering several scenarios must be carried out regarding minimization of oil spillages. Since the sorbent materials are decisive for sorption, it was approached the main sorbents: natural, graphenic, nano, polymeric and waste materials, and future trends.

Biosorbent with superhydrophobicity and superoleophilicity for spilled oil removal

The development of efficient and sustainable sorbents for emergent oil cleanup has attracted tremendous attention. In this study, the feasibility of enzymatic grafting of octadecylamine (ODA) on corn stalk pith (CSP) by laccase-TEMPO (2,2,6,6-tetramethylpiperidine-1-oxyl) treatment for enhanced oil-water separation was investigated. The dynamic contact angle tests suggest that the modified CSP (LCSP) had higher hydrophobicity (WCA, 157.2˚) and lipophilicity (OCA, 0˚) than the CSP did. In addition, the introduction of ODA onto the surface of modified CSP was verified by a variety of characterization techniques including SEM, FT-IR, and XPS. Compared with the control, laccase-TEMPO treatment of CSP coupled with octadecylamine grafting greatly improved the oil sorption capacity from 13.24 g/g to 44.25 g/g, while substantially reduced the water sorption capacity from 15.52 g/g to 2.76 g/g. LCSP has fast kinetic (sorption equilibrium reached before 60 min) and high fits to the pseudo-second-order kinetic model. The results obtained in this study reveal the feasibility of using Laccase-TEMPO treatment to graft the ODA onto the surface of CSP, thereby enhancing the rate and capacity of oil separation from oily water. The method and sorbent developed in this study hold promise for green, simple and cost-effective oil cleanup during oil spillage emergency events.

Facile Fabrication of Marine Algae-Based Robust Superhydrophobic Sponges for Efficient Oil Removal from Water

Water pollution caused by oil spillages has aroused worldwide attention. Therefore, it is of great significance to develop low-cost, environmentally friendly materials to remove oil contaminants from water. Herein, a "green" superhydrophobic sponge made from marine algae was fabricated by one-step growth of silicone nanofilaments onto a AgNP-decorated alginate sponge via chemical vapor deposition of an azeotrope of (CH₃)₃SiCl and SiCl₄. The reaction of the azeotrope with the alginate sponge was termed "instant", as it took only a few minutes (5 min) at room temperature to achieve superhydrophobicity (152.0°). Such sponges resist high temperatures, UV irradiation, organic solvents, and mechanical abrasion without losing the superhydrophobicity. The sponges absorbed oil droplets within seconds (1.3-7.0 s) with 11.7-17.1 g/g of sorption capacities for oils of different viscous levels (0.56-1775.00 mPa·s). These sponges could retain 90% of the initial oil sorption capacities after 10 consecutive oil sorption/desorption cycles. Benefiting from the superhydrophobicity and superoleophilicity, the sponges also exhibited high efficiency in oil/water mixture separation. Once the oil/water mixture was injected into the sponge, oil drops were retained in inner pores while water was rejected and spouted from the surface. These excellent performances make the resultant sponge a competitive material for oil spill emergency remediation.

Insights into the resources generation from pulp and paper industry wastes: Challenges, perspectives and innovations

Pulp and paper industry is swiftly budding to fulfill industrial needs and with the growth of this industry, a large amount of waste has also generated which includes biological sludge generated from the wood digestion process, fly ash accumulation and lime mud produced in chemical reagent recovery circuit. There are many health hazards associated with generated wastes and this waste material can be utilized in sustainable ways to generate useful resources through technological innovations. This review highlights a few useful aspects of waste conversion to resources like the production of green energy, sorbent development, and clinker preparation. The generation of resources from such wastes is a revolutionary and innovative concept for sustainable development including valorization of the generated waste to integrate pulp and paper industry with biorefinery. This review paper focuses on the sustainable utilization of waste from such industry along with its efficiency and future challenges.

Abstraction and regeneration potential of temperature-enhanced rice husk montmorillonite combo for oil spill

Chemical modification of montmorillonite though popular may be expensive and environmentally noxious and can result in secondary contamination. Therefore, there is a need for eco-friendly and efficient treatment techniques. The use of thermally enhanced rice husk montmorillonite combo (TRMC) for aqueous crude oil pollution was evaluated. The physical characterization of the sorbate revealed a light crude oil. Scanning electron microscopy of TRMC and untreated montmorillonite (UM) showed efficient utilization of the pores for crude oil sequestration. Temperatures, pH, initial oil concentration, dosage of sorbent, and time were found to be significant in the batch sorption investigation. The heterogeneous surface nature of TRMC was elucidated by the Freundlich and Scatchard model analyses. The Langmuir monolayer maximum sorption capacity was 5.8 and 9.7 g/g for UM and TRMC respectively and the latter was found to be higher than most reported sorbents. The pseudo-first-order model gave better fit than pseudo-second-order, the Bangham, and the Elovich models in kinetics based on regression and chi-square analysis. Thermodynamics showed a spontaneous, feasible, endothermic, and physical sorption processes. Regeneration and reusability studies using n-hexane as eluent showed TRMC as suitable, environmental friendly sorbents for oil spill remediation.

Superhydrophobic/superoleophilic cotton-oil absorbent: preparation and its application in oil/water separation

A superhydrophobic and superoleophilic oil sorbent was prepared by attaching SiO₂ particles onto a cotton fiber surface by a sol–gel method and subsequent octadecyltrichlorosilane modification. The surface formation was confirmed by Fourier transform infrared spectroscopy, scanning electron microscopy, and an observation of the water behavior on the cotton surface. The sorption capacity of the modified cotton in pure oil and in an oil/water mixture, the oil adsorption and the reusability were investigated. Compared with raw cotton, the as-prepared cotton absorbed different oils rapidly up to in excess of 25–75 g g⁻¹ its own weight, and the water adsorption was nearly 0 g g⁻¹. The modified cotton fiber could separate oil/water mixtures efficiently through a flowing system. After 10 cycles, the as-prepared cotton was still highly hydrophobic with a 6-times greater adsorption than raw cotton. By a simple modification, a low-cost, high-adsorption and environmentally friendly modified cotton could be prepared that can be considered a promising alternative to organic synthetic fibers to clean up oil spills.

A superhydrophobic and superoleophilic oil sorbent was prepared by attaching SiO₂ particles onto a cotton fiber surface by a sol–gel method and subsequent octadecyltrichlorosilane modification.

Efficiency of sugarcane bagasse-based sorbents for oil removal from engine washing wastewater

This work evaluates the efficiency of sugarcane bagasse-based sorbents in the sorption of oil from engine washing wastewater. The sorbents were obtained from sugarcane bagasse in the natural form (SB-N) and modified with either acetic anhydride (SB-Acet) or 3-aminopropyltriethoxysilane (SB-APTS). The results showed that the sorption capacity of these materials decreased in the following order: SB-APTS > SB-N > SB-Acet. The superior oil sorption capacity observed for SB-APTS was attributed to the polar amino end groups in the silane structure, which acted to increase the hydrophilic character of the fibers. However, all the sorbents obtained in this study were able to clean a real sample of wastewater from engine washing, leading to significant reductions in suspended matter, sediment, anionic surfactants, and turbidity.

Development of oil-spill sorbent from straw biomass waste: Experiments and modeling studies

The recovery of oil spilled on land or water has become an important issue due to environmental regulations. Canadian biomasses as fibrous materials are naturally renewable and have the potential to absorb oil-spills at different ranges. In this work, four Canadian biomasses were examined in order to evaluate their oil affinities and study parameters that could affect oil affinity when used as sorbent, such as average particle size, surface coating and reusability. Moreover, one oil sorption model was adopted and coupled with another developed model to approximate and verify the experimental findings of the oil sorbent biomasses. At an average particle size of 150-1000 μm, results showed that barley straw biomass had the highest absorbency value at 6.07 g/g, while flax straw had the lowest value at 3.69 g/g. Wheat and oat straws had oil absorbency values of 5.49 and 5.00 g/g, respectively. An average particle size of 425-600 μm indicated better absorbency values for oat and wheat straws. Furthermore, the thermal stability study revealed major weight recovery for two flame retardant coatings at hemicellulose and lignocellulose degradation temperature ranges. It was also found that oat straw biomass could be regenerated and used for many sorption/desorption cycles, as the reusability experiment showed only a 18.45% reduction in the oil absorbency value after six consecutive cycles. The developed penetration absorbency (PA) model showed oat straw adsorbed oil at the inter-particle level; and, the results of the sorption capacity model coupled with the PA model excellently predicted the oil sorption of raw and coated oat straws.

Preparation and Characterization of Lignocellulosic Oil Sorbent by Hydrothermal Treatment of Populus Fiber

This study is aimed at achieving the optimum conditions of hydrothermal treatment and acetylation of Populus fiber to improve its oil sorption capacity (OSC) in an oil-water mixture. The characteristics of the hydrolyzed and acetylated fibers were comparatively investigated by FT-IR, CP-MAS ¹³C-NMR, SEM and TGA. The optimum conditions of the hydrothermal treatment and acetylation were obtained at170 °C for 1 h and 120 °C for 2 h, respectively. The maximum OSC of the hydrolyzed fiber (16.78 g/g) was slightly lower than that of the acetylated fiber (21.57 g/g), but they were both higher than the maximum OSC of the unmodified fiber (3.94 g/g). In addition, acetylation after hydrothermal treatment for the Populus fiber was unnecessary as the increment of the maximum OSC was only 3.53 g/g. The hydrolyzed and the acetylated Populus fibers both displayed a lumen orifice enabling a high oil entrapment. The thermal stability of the modified fibers was shown to be increased in comparison with that of the raw fiber. The hydrothermal treatment offers a new approach to prepare lignocellulosic oil sorbent.