Volume 14 Issue 4

A superhydrophobic and flame-retardant filter paper was prepared by a simple immersion process intended for effective oil-water separation. Superhydrophobicity and flame retardancy were achieved via a magnesium hydroxide (Mg(OH)2) nanostructure formed on the filter paper surface and subsequent polydimethylsiloxane (PDMS) treatment. The surface chemical composition, phase structure, morphology, and wettability of the as-prepared paper were characterized by X-ray photoelectron spectroscopy (XPS), X-ray diffractometry (XRD), scanning electron microscopy (SEM), atomic force microscopy (AFM), and water contact angle (WCA) measurement. The as-prepared paper effectively separated both immiscible oil-water mixtures and oil-in-water emulsions while exhibiting good reusability and flame retardancy. Therefore, this study provided a simple method to prepare multifunctional filter paper, with promising potential applications in oily water treatment.

Recently, tree stumps have attracted attention as a source of woody biomass. This study investigated the practicability of brutian pine (Pinus brutia Ten.) root as an alternative raw material in the essential oil industry. The composition of volatile compounds of brutian pine root was investigated and compared with that of brutian pine stem wood. In the wood sample, the major volatile compound was α-pinene (32.69%) and in the root sample it was β-caryophyllene (25.41%). Terpenes (α-pinene, β-pinene, Δ3-carene, β-caryophyllene, and α-humulene) constituted the major compounds in the wood sample, whereas oxygen-containing components (linalool and (E)-anethole) were the main compounds in the root sample, in addition to terpenes (limonene, β-caryophyllene, and α-humulene). Monoterpenes, sesquiterpenes, terpene oxides, alcohols, aldehydes, ethers, esters, and ketones were identified as the main groups of volatile compounds in the wood and root samples of brutian pine. Except for monoterpenes, the amounts of the other main groups of volatile compounds were higher in the root sample than in the wood sample. The variation and number of detected volatile compounds indicate that the root of brutian pine might be a useful raw material for some industrial processes that use these volatile compounds in their production.

Lacquer wax represents a significant resource derived from the berries of Toxicodendron vernicifluum in China. The main chemical component of lacquer wax is fatty acid. The fatty acid isopropyl ester prepared from this acid has played a role in enhancing skin penetration and spreading properties, which makes it suitable for use as an important material in washing, cosmetics, and pharmaceuticals. In this study, the isopropyl ester of lacquer wax was synthesized by lipase-catalyzed transesterification for the first time ever. In addition, microemulsion of lacquer wax-based isopropyl ester (LW-IPE) was prepared by adding surfactant, co-surfactant, and water to solve the flocculation phenomenon of LW-IPE. The microemulsion was characterized by its stability, conductivity, viscosity, and particle size, which confirmed the formula of water-in-oil (W/O) microemulsion. The W/O microemulsion demonstrated an excellent thermodynamic stability in the temperature range between 20 °C and 40 °C and was stabilized with the addition of NaCl. In vitro evaluation of protection against ultraviolet light (UVA and UVB) demonstrated that arbutin in W/O microemulsion is capable to protect against UVA. This study is believed as providing valuable information on the performance of microemulsion systems suitable for use in the cosmetics and pharmaceuticals industries.

Cellulose nanocrystals (CNC) were successfully obtained from softwood pulp by p-toluenesulfonic acid (p-TsOH) hydrolysis under the treatment of p-TsOH mass concentration of 60%, temperature of 70 °C, reaction time of 4 h, and pulp to solution ratio of 1:20 (g / mL). Zeta potential and dynamic light scattering (DLS), scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), and thermogravimetric analysis (TGA) were used to characterize the physical-chemical properties of the CNC. Under these conditions, the CNC exhibited good thermal stability in the suspension with a high crystallinity index of 90.1%. The CNC had an average diameter of 4.87 nm and average length 175.5 nm with no undesired elemental contamination. The degradation temperature of the CNC was relatively high at 310 °C. Moreover, p-TsOH was recovered by crystallization technology, and the recovery rate was over 70%, providing an environmentally friendly way for the development of biomass materials.

Rice straw pretreated with NaOH can be used to develop a kind of filling material of building walls for a greatly improved self-bonding property. In this work it was shown that NaOH solution can easily destroy the internal tubular structure, thus decreasing the stability of the rice straw. The mechanism explaining effects of the pretreatment measure was examined by analyzing the ash content using scanning electron microscopy (SEM). It was found that the ash content in the rice straw, elements like oxygen, carbon, silicon, can be reduced by the pretreatment of the rice straw with 1% (mass/mass) NaOH solution for 24 h. The thorny structures, spherical protuberance structures, and rod-shaped particles originally attached on the rice straws’ surface decreased by 90% after the treatment of NaOH solution. The contact area was correspondingly increased, and the wetting property on the surface was improved. As a result, the “bite force” among the pretreated rice straw surfaces was enhanced, leading to an improvement in self-bonding.

A broad-spectrum substrate-imprinted adsorption and crosslinking double immobilized pectinase (SDP) was prepared using a universal modified pectin obtained through enzymatic hydrolysis as the imprinting substrate. Its structure was characterized by infrared spectroscopy, circular dichroism, and scanning electron microscopy. The results showed that 1) cross-linking increased the Schiff base in SDP, 2) immobilization barely changed the secondary structure such as α-helix and β-sheet of SDP, and 3) adhesives were evenly distributed on the surface after immobilization. Studies on the enzymatic properties of SDP showed that the substrate imprinting significantly improved heat resistance and neutralization resistance of SDP. For example, the relative activity of SDP at 35 to 75 °C and at pH 4.4 to 6.5 was 5% and 15% more than that of the adsorption and crosslinking double immobilized pectinase (DP), respectively. In addition, after 8 cycles of use, the relative enzyme activity of SDP still reached 39.5%. Moreover, use of SDP decreased the cation demand in whitewater by 10% compared with DP. Overall, the use of a broad-spectrum substrate for imprinting to obtain SDP provides a new idea and method for using pectinase in in complex systems such as juice clarification and wastewater treatment.

Kenaf was replaced by various amounts of empty fruit bunch (EFB) in natural rubber latex foam (NRLF). Five different compositions of kenaf/EFB (7/0, 5/2, 3.5/3.5, 2/5, 0/7 phr) were prepared by using the Dunlop method. The comparison of tensile properties, morphology, foam density, compressive strength, hardness, swelling, compression set, and accelerated aging of natural rubber latex foam (NRLF) were studied. The tensile strength, modulus at 100% (M100), foam density, compressive strength, hardness, and compression set decreased with increasing EFB loading. However, the elongation at break and swelling percentage of NRLF increased as the content of EFB decreased. Morphological studies showed that a higher amount of EFB weakened the interaction between EFB and NRLF matrix and increased the formation of cell windows. The EFB-filled NRLF also showed better tensile retention compared to kenaf filled NRLF.

Experiments were conducted in pots to study the effects of 2.5% rice straw and 1% rice straw ash on rice growth and bacterial community abundance in areas mined for heavy rare earth elements. The results showed that the incorporation of rice straw improved the pH value of soil, reduced the α-diversity of the soil bacterial community, improved the abundance of Proteobacteria and Firmicutes; reduced the abundance of Acidobacteria, Nitrospirae, etc.; reduced the abundance of Candidatus Solibacter, Syntrophobacter, Haliangium, Candidatus Koribacter; and increased the abundance of Ideonella, Anaeromyxobacter, Roseomonas, Clostridium sensu stricto 10, and Geobacter. The decrease in the abundance of beneficial bacteria, Acidobacteria and Nitrospirae, inhibited the growth of the rice; reduced the dry weight of the rice roots, the shoots, and the grains, and increased the concentration of rare earth elements in the rice. Returning 1% rice straw ash to the field had little effect on the diversity and richness of the bacterial community in areas mined for heavy rare earth elements. Also the returned rice straw had little effect on the rice growth, the dry weight of the roots, the shoots, the grains, and the concentration of rare earth elements in these parts of the rice.

The relationship between the types of pulp, the tissue making technologies, and shelf price of bath tissue was evaluated for the North American market. Twenty-four market tissue samples (representing approximately 80% of the current market offering) were sourced and analyzed along with their nationwide price information. Pulp composition, drying technologies, market share, sustainability advertising, and tissue properties were evaluated. Tissue properties, including softness, ball burst strength, water absorbency, density, tensile strength, and tensile modulus were measured. Among all the drying technologies, creped through-air dry (CTAD) and creped through-air dry belt (CTADB) seemed to improve tissue softness most. The UCTAD maximized tissue bulk by drying the tissue web solely using a through-air (TAD) cylinder. Tissue samples with freeness between 575 to 650 mL seemed to have their properties improved more significantly through advanced drying technologies. It was found that the retail prices of these bath tissues were directly related to softness, bulkiness, water absorbency, and basis weight. A mathematical model was conducted to predict the retail price of bath tissue (based on product performance and attributes). This paper also identified the effect of “sustainability” on the retail price.

The use of freely suspended cells of microalgae culture to treat wastewater is of current global interest because of their effective photosynthetic uptake of pollutants, carbon dioxide sequestration, and biomass production for desirable high value-products. Biomass immobilization is a promising option to overcome the harvesting problem that is encountered when using free-cells upon completion of the wastewater treatment process. In this study, Nannochloropsis sp. cells were immobilized in sodium alginate beads to eliminate the harvesting limitation. The microalgal beads were further cultivated in treated palm oil mill effluent (TPOME) for removal of chemical oxygen demand (COD). The effect of POME concentration on COD removal and microalgal cells growth was investigated, respectively. It was found that the maximum biomass concentration of 1.23 g/L and COD removal of 55% from 10% POME were achieved after 9 days. An increment of POME concentration did not cause any improvement to the treatment efficiency due to the inhibitory effect of high initial COD of POME on the biomass concentration and was further responsible for low COD removal. The immobilized cells showed a systematic growth, demonstrating that the beads are biocompatible as immobilization carrier. In conclusion, the immobilized microalgal cells could be a viable alternative technology system for POME treatment as well as biomass production.