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In this study, biochar derived from sewage sludge was applied to remediate Cu and Cd co-polluted soil in semi-arid areas for the first time, in which the effects of biochar on the improvement of soil physicochemical and biological properties as well as the immobilization of Cu and Cd were investigated. Soil water holding capacity increased by 0.22–2.74%, soil CEC increased by 0.52–4.06 units, soil SOM content increased by 1.41–5.97 times, and urease and catalase activities increased by 0.012–0.032 mg·g−1·24 h−1, 0.18–2.95 mg H2O2·g−1, but soil pH increased only slightly by 0.69 units after biochar application. In addition, although the total content of these two metals in the soil increased with the use of biochar, the content of DTPA-Cu and Cd decreased by −0.128–0.291 mg/kg, 0–0.037 mg/kg, with the increase in biochar application, and the content of acid-soluble Cu in the soil decreased from 27.42 mg/kg to 3.76 mg/kg, the mobility and bioavailability of these two metals in the soil decreased. Finally, the complexation of organic functional groups with the soil dominates the immobilization process of metals, especially Cu. These findings suggest that biochar from sewage sludge can effectively improve soil quality and remediate heavy metal-contaminated soils in semi-arid regions. Meanwhile, the use of sludge-based biochar for the remediation of contaminated soils also provides a new method for the safe disposal of sewage sludge and a new way for sustainable development. In subsequent studies, methods such as modification are recommended to improve the efficiency of sludge-based biochar for the removal of Cu and Cd. [ABSTRACT FROM AUTHOR]

Biomass is an attractive raw material for the production of fuel oil and chemical intermediates due to its abundant reserves, low price, easy biodegradability, and renewable use. Hydroxymethylfurfural (5‐HMF) is a valuable platform chemically derived from biomass that has gained significant research interest owing to its economic and environmental benefits. In this review, recent advances in biomass catalytic conversion systems for 5‐HMF production were examined with a focus on the catalysts selection and feedstocks' impact on the 5‐HMF selectivity and yield. Specifically, the potential of zeolite‐based catalysts for efficient biomass catalysis was evaluated given their unique pore structure and tunable (Lewis and Brønsted) acidity. The benefits of hierarchical modifications and the interactions between porosity and acidity in zeolites, which are critical factors for the development of green catalytic systems to convert biomass to 5‐HMF efficiently, were summarized and assessed. This Review suggests that zeolite‐based catalysts hold significant promise in facilitating the sustainable utilization of biomass resources. [ABSTRACT FROM AUTHOR]

Irreversible pollution by heavy metals such as lead (Pb) and cadmium (Cd) adversely affects the ecological environment and human health. Due to its high adsorption, microporosity, and specific surface area, biochar possesses excellent potential for use in heavy metal pollution remediation. The preparation of mixed-based biochar from sludge and cotton stalk can solve the problems inherent to pure sludge biochar, such as undeveloped pore structure and a small specific surface area, while resourcefully utilizing both waste biomass types. This study investigated the adsorption capacity for Pb2+ and Cd2+ of mixed-based biochar prepared at different pyrolysis temperatures, different pyrolysis residence times, and different cotton stalks percentages. Response surface experiments revealed the optimum process conditions for preparing mixed-based biochar, which included a pyrolysis temperature of 638 °C, a pyrolysis residence time of 86 min, and an addition ratio of 50% for cotton stalks. The isothermal adsorption experiments revealed that the maximum adsorption capacities of mixed-based biochar for Pb2+ and Cd2+ were 111.11 and 86.21 mg/g, respectively. Our findings suggest the co-pyrolysis of sludge and cotton stalk as a green and sustainable method for safely disposing of Pb and Cd. [ABSTRACT FROM AUTHOR]

With the development of modern lighting and display technology, the color tuneable phosphors have been widely investigated for their application. In order to achieve the color tuneable phosphors, series of Mg 2 Y 2 Al 2 Si 2 O 12 :Eu2+ and Mg 2- x Y 1.99 Al 2 Si 2 O 12 : x Mn2+, 0.01Eu2+ are synthesized. In the host compound, Eu2+ does replace Y3+ non-equivalently, which affects the garnet structure of the samples, and then the internal environment of the crystal affects the energy level splitting of Eu2+, which causes the emission peak of Mg 2 Y 2-y Al 2 Si 2 O 12 :yEu2+ shifts from 425 nm to 495 nm. When codoped Mn2+/Eu2+, the emission color of Mg 2- x Y 1.99 Al 2 Si 2 O 12 : x Mn2+, 0.01Eu2+ can turn from blue to white with increase Mn2+ concentration, and the color coordinates of Mg 1.4 Y 1.99 Al 2 Si 2 O 12 :0.6Mn2+, 0.01Eu2+ locate at (0.3254, 0.2669), and its color temperature is 5791.19 K. The results show that this phosphor may be a potential application to the white light emitting diodes. [ABSTRACT FROM AUTHOR]

We experimentally investigate segregation behaviors of binary granular mixtures consisting of granular chains and spherical grains with different interstitial media under vertical vibrations. A quantitative criterion is proposed to locate the boundaries between different vibrating phases. The water-immersed granular mixture exhibits two interesting types of segregation behaviors: chain-on-top and sandwich patterns. However, the phenomenon of sandwich segregation is absent for the air-immersed mixture. The topological differences of phase diagrams between two different environments indicate that the interstitial fluid plays an important role on the granular demixing. Additionally, the phase behaviors of mixtures for the different chain lengths show a not significant discrepancy. Finally, the vibrating thickness ratio determining the phase boundary characterizes the mixing extent of the granular bed. The estimated ratios for various chain lengths exhibit a monotonically decreasing dependence, when the vibration frequency increases.