Application of carboxymethyl cellulose sodium (CMCNa) in maize-wheat cropping system (MWCS) in coastal saline-alkali soil

Sodium carboxymethyl cellulose (CMCNa) application has been a promising approach to improve soil quality. The purpose of this study was to explore the effects of CMC-Na on soil infiltration, evaporation, water-salt distribution, crop growth, water use efficiency and net profit (Net) in a coastal saline-alkali soil maize-wheat cropping system (MWCS). Five CMC-Na application amounts (0, 0.1, 0.2, 0.4 and 0.6 g kg-1) were designed for the soil column experiment indoor, and five CMC-Na application amounts were used in 2019-2020 field experiment (CK: 0, C10: 10 kg ha-1, C20: 10 kg ha-1, C30: 10 kg ha-1 and C50: 10 kg ha-1), No treatment will be applied in 2021. The results showed that (1) CMC-Na treatment reduced soil cumulative infiltration, infiltration rate, daily evaporation, and cumulative evaporation. (2) After the application of CMCNa, the average soil water storage (SWS) in the 0-60 cm soil layer increased, and soil salinity (SSC) decreased in most treatments. (3) In the 2019-2020, the maize aboveground biomass (B), yield (Y) and water use efficiency (WUE) were the highest under the C20 and C30 treatments, which were 15.24 and 15.32 t ha-1, 5.67 and 5.49 t ha-1 and 1.74 and 1.52 kg ha-1 mm-1, respectively, and the wheat under C30 treatment is the highest, which were 10.98 t ha-1, 5.27 t ha-1 and 1.78 kg ha-1 mm-1. (4) A dose of 25.5 kg ha-1 and 38.9 kg ha-1 was recommended as the most optimal CMC-Na application for maize and wheat in coastal saline alkali soil, respectively.

Soy protein isolate/carboxymethyl cellulose sodium complexes system stabilized high internal phase Pickering emulsions: Stabilization mechanism based on noncovalent interaction

The interactions between carboxymethyl cellulose sodium and proteins can regulate the interfacial and rheological properties of HIPEs, which plays a leading role in the stabilities of HIPEs. This article prepared various ratios of soluble soy protein isolate/carboxymethyl cellulose sodium (SPI/CMC) complexes in different proportions and examined the impact of various ratios of complexes on the structure and interface properties of complexes systems. Additionally, it explored the co-emulsification mechanism of HIPEs using SPI and CMC. At appropriate ratios of SPI/CMC, SPI and CMC mainly combine through non covalent binding and form complexes with smaller particle sizes and stronger electrostatic repulsion. The interfacial properties indicated that adding appropriate CMC increased the pliability and reduced the interfacial tension, while also enhancing the wettability of SPI/CMC complexes. At the ratio of 2:1, the SPI/CMC complexes-stabilized HIPPEs exhibited smaller oil droplets size, tighter droplet packing, and thicker interfacial film through the bridging of droplets and the generation of stronger gel-like network structures to prevent the coalescence/flocculation of droplets. These results suggested that the appropriate ratios of SPI/CMC can improve the physical stability of HIPEs by changing the structure and interface characteristics of the SPI/CMC complexes. This work provided theoretical support for stable HIPEs formed with protein-polysaccharide complexes.

Synergistic effects of biochar and carboxymethyl cellulose sodium (CMC) applications on improving water retention and aggregate stability in desert soils

Making improvements to the water-holding characteristics and water-erosion resistance of desert soils, particularly in inland extremely arid areas, is vital for achieving both sustainable water resource utilisation and food security. The aim of this study is to evaluate the effects of the co-application of biochar and carboxymethyl cellulose sodium (CMC) on the physical properties of sandy desert soil, including infiltration rate, saturated water conductivity, field water-holding capacity and aggregate stability. Sandy desert soil samples were collected from jujube plantations on the southern edge of the Taklimakan Desert in the Hotan Prefecture, Xinjiang, China. Five CMC application ratios (C0:0, C1:0.01 g/kg, C2:0.02 g/kg, C3:0.04 g/kg and C4:0.08 g/kg) and five biochar application ratios (B0:0, B1:1.0 g/kg, B2:2.0 g/kg, B3:4.0 g/kg and B4:8.0 g/kg) were designed and a total of 11 experimental treatments were performed, which were labelled as CK (control group), B2C0, B2C1, B2C2, B2C3, B2C4, B4C4, B0C2, B1C2, B3C2 and B4C2. Compared with CK, the combined application of biochar and CMC reduced the soil bulk density (BD) by 1.29-9.41% and the saturated hydraulic conductivity (K_s) by 29.64-94.98%, and increased the soil saturated water content (SSWC) by 8.81-30.74% and the water holding capacity (WHC) by 13.91-36.87%. Similarly, the water-stable aggregates that were co-applied with biochar and CMC increased by 29.10-256.86%. This resulted in significant improvement in the stability of sandy desert soil against water erosion. The principal component analysis (PCA) results found B4C4 to have the best comprehensive improvement effect. Therefore, 0.08 g/kg of CMC and 8.0 g/kg of biochar were used as recommended for improving the hydraulic properties of desert soils. Generally, CMC and biochar have a mutually complementary effect on improving sandy desert soil, providing new ideas and approaches for the improvement of soil and the sustainable development of agriculture in desert areas.

Preparation of combined hydrogel solution that is suitable to control the emission of odor pollutants from brownfield site and its control effects

Odor pollution caused by brownfield site has attracted increasing attention. However, to date, fewer suitable materials can be used to control the emission of odor pollutant from brownfield site during remediation. This study prepared a kind of combined hydrogel solution based on sodium alginate and carboxymethyl cellulose sodium (CHS-SC) and tested the possibility of its membrane in controlling the emission of three odor pollutants (trichloroethylene, dimethyl disulfide, and p-xylene) from polluted soil. Our results showed that CHS-SC membrane could effectively control the emission of three odor pollutants from polluted soil. Comparatively, CHS-SC membrane had higher control rates for three odor pollutants at high ambient temperature (32 °C), short storage time of CHS-SC (5 days, 25 °C), and low odor pollutant concentration (2 ml/kg soil) than at low ambient temperature (2 °C), long storage time of CHS-SC (10 d, 25 °C), and high odor pollutant concentration (4 ml/kg soil), respectively. CHS-SC membrane was degraded by 79.23% after 150 days in soil and slightly changed soil bacterial community, indicating that it had good biodegradability and environmental friendliness. In addition, CHS-SC cost was the lowest among the products with similar function. This study shows that CHS-SC is effective in short-timely controlling the emission of odor pollutants from brownfield site.