Cheng Zhang

Biochar (BC) and hydrochar (HC) have attracted increasing attention as sustainable soil amendments for improving soil water retention and mitigating agricultural water stress. This review synthesizes and compares the current state of knowledge on the production, physicochemical properties, and hydraulic performance of slow-pyrolysis BC, hydrothermal carbonization hydrochar (HTC HC), and hydrothermal liquefaction hydrochar (HTL HC). The mechanisms governing soil water retention are first examined, followed by a comprehensive review of the effects of amendment properties, feedstock type, thermochemical conversion conditions, particle size, application rate, and soil characteristics on field capacity, permanent wilting point, plant-available water, and water-holding capacity. The available evidence demonstrates that BC generally provides the most consistent improvement in soil hydraulic properties, particularly in coarse-textured soils, whereas the performance of HTC HC is considerably more variable and strongly dependent on hydrothermal conversion conditions and soil characteristics. HTL HC remains largely unexplored but shows promising hydraulic performance and exceptional resistance to biodegradation. Apparently contradictory findings among published studies are shown to arise largely from interactions among feedstock and conversion conditions, resulting amendment properties, soil characteristics, application conditions, and differences in hydraulic evaluation, highlighting the need for integrated mechanistic frameworks rather than interpretation based on individual factors. A comparative assessment of the three materials further considers ecotoxicity, biodegradation, life-cycle assessment, and techno-economic analysis. Overall, BC is currently the most mature soil amendment technology, HTC HC offers important advantages for wet biomass utilization, and HTL HC represents a promising but underdeveloped alternative. Future research should emphasize standardized evaluation methods, long-term field validation, and integrated mechanistic approaches linking production conditions, amendment properties, soil characteristics, and application conditions to enable predictive, application-specific design of carbonaceous soil amendments for sustainable soil water management.

Extensive research has been conducted on the application of pyrolysis and hydrothermal carbonization (HTC) biochar for soil amendment. However, hydrochar from hydrothermal liquefaction (HTL) has received little attention regarding its potential for such application. This research paper aims to fill this knowledge gap. In this study, corn stover-derived hydrochar from HTL at 280 °C was characterized using suitable analytical techniques to determine the functional groups, specific surface area, and morphology. The effects of HTL hydrochar on water holding capacity (WHC) and water retention of sandy loam soil and the resistance to biodegradation were also studied. The BET surface area of hydrochar was found to be 27.6 m²/g. The hydrochar particles are micro-sized stacking of nanometer-thick foliates. The hydrochar-amended soil consistently showed better WHC ranging from 50 to 55% compared to the unamended soil of 48%. A similar trend was observed for water retention over a period of four days. No notable biodegradation was observed for the hydrochar over a period of 106 days in wet soil at the ambient temperature. Overall, these results demonstrate the potential of HTL hydrochar as a valuable soil amendment to enhance agriculture sustainability.

Extensive research has been done on applications of pyrolysis biochar to amend soil. However, no research has been done on hydrothermal liquefaction (HTL) hydrochar regarding its potential for soil amendment. In this study, corn stover derived hydrochar from HTL at 280 °C were characterized using suitable analytical techniques to determine the functional groups, specific surface area and morphology. The effects of HTL hydrochar on water holding capacity (WHC) and water retention ability of sandy loam soil and the resistance to biodegradation were also studied. The BET surface area of hydrochar was found to be 27.61 m2/g. The hydrochar particles are micro-sized stacking of nanometer-thick foliates. The hydrochar amended soil consistently showed better WHC ranging from 50 -55 % compared to the unamended soil of 48 %. Similar trend in results were observed for water retention over a period of four days. No notable biodegradation was observed for both the hydrochar and the heavy biocrude over up to over 115 days in soil or potting mix. Overall, these results demonstrate the potential of HTL hydrochar as a valuable soil amendment to enhance agriculture sustainability.

Laccases are multi-copper oxidases that play an important role in the biodegradation of phenolic compounds, lignin, dye, and wastes. Here, we report the screening of potential laccase-producing indigenous bacterial isolates and subsequent optimization of laccase production using crop residues as cheap supplementary energy sources. Among 16 bacterial isolates, seven were selected based on the appearance of reddish-brown bacterial colonies and guaiacol oxidation assay after 10 days of incubation at 37 °C. The maximum laccase activity (2.755 U/mL) was observed for bacterial isolate WR2. Response surface methodology (RSM) was used to maximize laccase production from WR2, identified as Pseudomonas stutzeri . Plackett–Burman design (PBD) was employed to design production runs involving various factors including time, pH, inoculum, wheat straw, cotton stalk, wheat bran, rice straw, copper sulfate, sugarcane bagasse, yeast extract, and peptone. The interactions of different factors were analyzed from the responses (laccase enzyme activity, etc.) in 12 experimental runs. In experimental run 4, the maximum laccase enzymatic activity (1.86 U/mL) was achieved after a 10-day incubation with wheat straw (1%) and cotton stalk (1%) at pH 6.8 and 37 °C, and high-degree lignin degradation was evident from a substantial reduction in the FTIR aromatic stretching peak of the degraded biomass.

After decades of discussions, it has been firmly established that detectors made of silicon-based semiconductor materials can be effectively used for neutron detection by simply coating them with suitable substances. The incident thermal neutrons interact with the coating neutron-sensitive materials such as ¹⁰B and ⁶LiF, resulting in the production of secondary charged particles which can be effectively detected in the sequencial silicon substrate. In this article, the detector system was designed with a coupled neutron detector structure which combined a silicon detector with a ¹⁰B₄C film in various forms. The ¹⁰B₄C layer was deposited on the substract with electron beam evaporation method. Two kinds of structrue were discussed: (1) one was the direct contact neutron detector by depositing ¹⁰B₄C directly onto the front surface of silicon-based detectors; (2) the other was the coupled neutron detectors by depositing ¹⁰B₄C onto substrates made from different materials such as Al and glass which then coupled with silicon-based detectors. The responses of these neutron detectors to neutrons (Cf-252) were measured individually. It's showen that the detection capability of direct contact neutron detectors was lower than the coupled neutron detectors. For the coupled detectors, the detector by depositing ¹⁰B₄C on the aluminum substrate was found to be superior than that by depositing ¹⁰B₄C on the glass substrate.

Short-term power load forecasting has been closely linked with the modernization of power system management, which is an important guarantee for the safe and stable operation of power system and the improvement of economic benefits. Based on the combination algorithm of wavelet transform and particle swarm gray neural network, this paper presents a new short-term power load prediction model. The power load is decomposed into different frequency components from coarse to fine by multi-resolution analysis of wavelet transform. The unit root test method is used to select the most appropriate wavelet decomposition layers, the decomposed wavelet components according to their different characteristics to build their own grey neural network prediction models, and the particle swarm optimization algorithm is used to optimize the weight threshold to solve the problem of local minimization. Finally, the expected prediction results are obtained through the wavelet reconstruction. Through a practical example, the results show that the short-term power load prediction model based on combinatorial optimization proposed in this paper has a high prediction accuracy, which verifies the rationality and feasibility of the prediction model. It has important guiding significance for the power department to maintain the safe and stable operation of the power grid and realize the economical and reasonable power dispatching.

In this study, cationic cellulose (CC) was prepared by etherifying commercial cellulose with (3-chloro-2 hydroxypropyl) trimethylammonium chloride (CHPTAC) in an alkaline medium. The prepared CC was characterized using Fourier transform infrared spectrometry (FTIR), scanning electron microscopy (SEM), differential scanning calorimetry (DSC), and nuclear magnetic resonance (NMR). The characterization results affirmed the successful cationization of cellulose. Upon optimization of reaction conditions, a CC sample with a degree of substitution (DS) of 0.857 was achieved. The CC sample was then tested as a flocculant or sorbent in three environmental applications: algal harvesting, solid removal from dairy wastewater, and capture of methyl orange (MO) in dye wastewater. The effects of dose level and pH on flocculation/sorption performance were studied. Under the optimal dose level and pH conditions, up to 90.4% of dry algal biomass and 53.3% of suspended solids in the dairy wastewater were removed, as measured by standard jar testing. Around 64.2% of MO in the synthetic wastewater was sorbed on the prepared CC and removed, as determined by absorbance at 463 nm. The new CC preparation method exempts the pre-dissolution of cellulose in a solvent and is expected to promote the application of CC in water treatment and the alike scenarios.

A cationic starch flocculant was prepared from potato peel waste (PPW) for enhanced solid–liquid separation of livestock wastewater, thereby promoting the agricultural circular economy. The starch extracted from PPW was cationized by incorporating a cationic moiety onto the backbone of starch via etherification with (3-chloro-2-hydroxypropyl)trimethylammonium chloride (CHPTAC). Using response surface methodology, a cationic starch sample with a degree of substitution (DS) = 0.86 was obtained from optimized reaction conditions: 1 wt% starch, 0.124 M CHPTAC, 2.0 M NaOH, isopropanol solvent, 60 °C and 5 h. ¹H NMR and FTIR confirmed the successful cationization of starch. A detailed analysis of the NMR spectra indicates that the substitution happened at all three OH groups of the anhydroglucose unit, and some of the proton peak assignments in the literature are mistaken. The DS = 0.86 sample was further studied for its flocculation performance. When used to treat undiluted swine and dairy wastewater (with high total suspended solid levels of 51.4 and 45.0 g L⁻¹), despite a moderate suspended solid (SS) reduction (27.8 and 58.0%), the SS removal efficiency (72 and 162 mg SS per mg flocculant achieved at the optimal dosages of 200 and 160 mg L⁻¹ for swine and dairy wastewater, respectively) was greater than that of commercial flocculant PAM and some other flocculants in the literature that were used to treat highly diluted livestock wastewater.

We are reporting the optical study of two types of poly (3-thienylene vinylene) (PTV) derivatives with linear and bulk side chain configurations. The first one, poly(3-dodecylthienylenevinylene) with controlled regioregularity (PTV-CR) with an alkyl side group, showed a high degree of crystallinity, whereas the second one, imide-PTV with an electron deficient imide side group, is amorphous. Continuous wave-photoinduced absorption revealed different features of the long-lived triplet absorptions, with the geminately generated triplet–triplet pair in imide-PTV bearing more intrachain characteristics with fast recombination kinetics (μs). On the other hand, the isolated triplet in PTV-CR generated by intersystem crossing had more interchain characteristics with slow recombination kinetics (ms). The decay of the triplet–triplet pair in imide-PTV is monomolecular even at a high pump intensity of 240 mW/cm², whereas the isolated triplets in PTV-CR recombine bimolecularly at a very low pump intensity of 10 mW/cm². Grazing incidence X-ray diffraction, doping induced absorption, and various dependences of the photoinduced absorption spectrum have corroborated the finding that reduced interchain interaction favors the formation of a correlated triplet–triplet pair, a precursor to two independent triplets formed via fission.