Waste straw biomass is an abundant renewable bioresource raw material on Earth. Its stubborn wooden cellulose structure limits straw lignocellulose bioconversion into value-added products (e.g., biofuel, chemicals, and agricultural products). Compared to physicochemical and other preprocessing techniques, the steam explosion method, as a kind of hydrothermal method, was considered as a practical, eco-friendly, and cost-effective method to overcome the above-mentioned barriers during straw lignocellulose bioconversion. Steam explosion pretreatment of straw lignocellulose can effectively improve the conversion efficiency of producing biofuels and value-added chemicals and is expected to replace fossil fuels and partially replace traditional chemical fertilizers. Although the principles of steam explosion destruction of lignocellulosic structures for bioconversion to liquid fuels and producing solid biofuel were well known, applications of steam explosion in productions of value-added chemicals, organic fertilizers, biogas, etc. were less identified. Therefore, this review provides insights into advanced methods of utilizing steam explosion for straw biomass conversion as well as their corresponding processes and mechanisms. Finally, the current limitations and prospects of straw biomass conversion with steam explosion technology were elucidated.

Morel is a popular edible mushroom with considerable medicinal and economic value which has garnered global popularity. However, the increasing heavy metal (HM) pollution in the soil presents a significant challenge to morels cultivation. Given the susceptibility of morels to HM accumulation, the quality and output of morels are at risk, posing a serious food safety concern that hinders the development of the morel industry. Nonetheless, research on the mechanism of HM enrichment and mitigation strategies in morel remains scarce. The morel, being cultivated in soil, shows a positive correlation between HM content in its fruiting body and the HM content in the soil. Therefore, soil remediation emerges as the most practical and effective approach to tackle HM pollution. Compared to physical and chemical remediation, bioremediation is a low-cost and eco-friendly approach that poses minimal threats to soil composition and structure. HMs easily enriched during morels cultivation were examined, including Cd, Cu, Hg, and Pb, and we assessed soil passivation technology, microbial remediation, strain screening and cultivation, and agronomic measures as potential approaches for HM pollution prevention. The current review underscores the importance of establishing a comprehensive system for preventing HM pollution in morels.

As an environmental management method, the (life cycle assessment) LCA method can be used to compare the differences between various waste treatment processes in order to provide an environmentally friendly and economically feasible method for waste management. This study focused on the reutilization of typical organic waste to produce organic fertilizer in southwest China and used the life cycle assessment method to evaluate three aerobic chicken manure composting scenarios modified with three additives (biochar, mushroom bran, and tobacco residue) from an environmental and economic perspective. The results show that the total environmental loads of the optimized treatments using mushroom bran and biochar mixed with mushroom bran as additives were reduced by 30.0% and 35.1%, respectively, compared to the control treatment (viz. chicken manure composted with tobacco residue). Compared to the control treatment, the optimized composting treatment modified by mushroom bran with and without biochar improved the profit by 23.9% and 35.4%, respectively. This work reflected that the combined composting mode of chicken manure, tobacco residue, mushroom bran, and biochar is an environmentally friendly and economically feasible composting process, which is more suitable for the resource utilization of the typical organic waste in southwest China.

Biochar (BC) and organic fertilizers (OFs) are both organic soil amendments that can be used to improve soil quality, but their effects on soil physicochemical properties and microbial structures may be different. Comparative studies can help us understand the advantages and disadvantages of different types of soils. In the current research, five treatments, including a control group (CK), two concentrations of biochar (2% BC and 4% BC), and two concentrations of organic fertilizer (2% OF and 4% OF) and their effects on soil properties, enzyme activities, and bacterial diversity were evaluated. The BC and OF significantly increased the soil EC, pH, and soil nutrients (p < 0.05). The 2% BC increased the biomass of Pennisetum giganteum by 41.7%. The 4% BC and OF reduced the biomass of P. giganteum. Furthermore, the observed decrease in the P. giganteum yield following the application of the 4% BC can be attributed to reductions in the available phosphorus (AP) and CaCl₂-P, as well as alterations in the soil enzyme activity. However, the negative impact of OFs on crop yield may be associated with an increased EC, elevated abundance of soil-borne pathogens, and decreased levels of beneficial microorganisms. In summary, a comparative study of the effects of BC and OF on the growth of P. giganteum in acidic soil is of great significance for improving the soil quality, promoting the development of organic agriculture, protecting the environment, and promoting land reclamation.

Forward osmosis membrane technology (FO) shows potential application prospects in biogas slurry concentration, which is conducive to promoting the sustainable development of biogas projects. However, at present, the key influencing factors of membrane concentration using FO are not well understood. Therefore, this study analyzed the influence of draw solution concentration, pH, temperature and cross-flow velocity on the concentration efficiency of FO membrane, and optimized the operation parameters of FO membrane. The results showed that the concentration effect of the NaCl draw solution at pH 5 or 9 was better than that at pH 7. The order of factor influencing the water flux was as follows: draw liquid concentration > cross-flow velocity > operating temperature. The optimal combination obtained by orthogonal analysis was under 45 °C, with a cross-flow velocity of 1 L/min and the use of 1.5 mol/L NaCl as draw solution. The results of the membrane cleaning implied that the recovery rate of the fouled membrane after acid–base cleaning is significantly higher (88%) than other cleaning solutions. This research offers a scientific reference for applying positive osmosis technology to re-utilize biogas slurry resources.

Biochar is widely used to maintain crop yields and the sustainability of agroecosystems due to its characteristics. However, its effect on vegetable yield and quality in southern acidic soils has not been fully elucidated. The effects of two kinds of biochar application rates (3 t ha⁻¹ and 12 t ha⁻¹) on the nutrient availability, nutrient absorption, yield, and fruit quality of sandy acid oxide soil in South China were studied in a 2-year field experiment using two varieties of wax gourd (Tiezhu No. 2 and Dadao). The results showed that optimized fertilization (OPT, nitrogen, phosphorus, and potassium were reduced by 20.0%, 20.6%, and 21.1%, respectively) did not reduce the yield of the different varieties of wax gourd compared to FP (farmer practice). On the basis of the OPT treatment, the application of biochar increased the yield of Tiezhu No. 2 and Dadao wax gourd by 16.0–27.3% and 7.7–13.3%, respectively. The increase in yield was attributed to the improvement in soil organic carbon content which increased by 4.5–19.7%, nutrient effectiveness (NO₃⁻-N and Olsen-P content enhanced by 23.7–27.0% and 15.3–23.4% in Tiezhu No. 2), and nutrient uptake (N, P, K, Ca, and Mg accumulation increased significantly by 21.1%, 46.1%, 36.8%, 25.7%, and 31.9%, respectively) by the plant after the biochar application. Different types of biochar also have some differences in these three aspects. Specifically, under the same dosage, rice biochar has a more significant effect on increasing the yield of winter melon, and has a better effect on the improvement of soil physical and chemical properties, while sawdust biochar has a more significant effect on nutrient absorption. In addition, the commercial quality, namely hardness and glossiness, and the nutritional quality, namely soluble sugar, soluble protein, VC content, and sugar–acid ratio of wax gourd fruits, were significantly improved after the biochar application. In summary, biochar application on acidic soils in South China could achieve a win–win situation in terms of increasing soil nutrient effectiveness to improve vegetable yield and quality while reducing chemical fertilizer.