Using organic wastewater to produce hydrogen by fermentation can generate clean energy while treating wastewater. At present, there are many inhibitory factors in the hydrogen production process, resulting in unsatisfactory hydrogen yield and hydrogen concentration during the fermentation process, and there are still great obstacles to the industrial promotion and commercial application of organic wastewater fermentation hydrogen production. This paper summarizes the hydrogen production of organic wastewater dark anaerobic fermentation technology. The current anaerobic fermentation hydrogen production systems and technologies are summarized and compared, and the factors and potential conditions that affect the performance of hydrogen production are discussed. The further requirements and research priorities for the market application of fermentation biohydrogen production technology in wastewater utilization are prospected.

Due to the intensification of the greenhouse effect and the emphasis on the utilization of CO₂ resources, the enrichment and separation of CO₂ have become a current research focus in the environment and energy. Compared with other technologies, pressure swing adsorption has the advantages of low cost and high efficiency and has been widely used. The design and preparation of high-efficiency adsorbents is the core of the pressure swing adsorption technology. Therefore, high-performance porous CO₂ adsorption materials have attracted increasing attention. Porous adsorption materials with high specific surface area, high CO₂ adsorption capacity, low regeneration energy, good cycle performance, and moisture resistance have been focused on. This article summarizes the optimization of CO₂ adsorption by porous adsorption materials and then applies them to the field of CO₂ adsorption. The internal laws between the pore structure, surface chemistry, and CO₂ adsorption performance of porous adsorbent materials are discussed. Further development requirements and research focus on porous adsorbent materials for CO₂ treatment in industrial waste gas are prospected. The structural design of porous carbon adsorption materials is still the current research focus. With the requirements of applications and environmental conditions, the integrity, mechanical strength and water resistance of high-performance materials need to be met.

Geology forms the basis for underground space development. In mountainous plateau areas, developing underground spaces requires detailed analyses and appraisal. This study used the index scale analytic hierarchy process (AHP) to analyze the geological conditions and to propose an evaluation system suitable for Kunming, China. An evaluation model was established using mathematical principles, and a geological suitability evaluation of Kunming was conducted using GIS. According to the evaluation, underground space in Kunming considered suitable, medium suitable, unsuitable, and forbidden for development accounts for 37.81%, 20.38%, 17.61%, and 24.2% of its total area, respectively. Soft soil and karst topographies are the primary disqualifying factors, followed by groundwater and geological fault zones. Our results reveal that most of the underground spaces in the plateau area are suitable for development. However, there are areas where construction should be strictly regulated, such as those adjacent to geological fault zones. With this study, the superiority of the index scale method was demonstrated, and the consideration criteria of the evaluation system and indexes in plateau cities were proposed.

Geospatial data is an indispensable data resource for research and applications in many fields. The technologies and applications related to geospatial data are constantly advancing and updating, so identifying the technologies and applications among them will help foster and fund further innovation. Through topic analysis, new research hotspots can be discovered by understanding the whole development process of a topic. At present, the main methods to determine topics are peer review and bibliometrics, however they just review relevant literature or perform simple frequency analysis. This paper proposes a new topic discovery method, which combines a word embedding method, based on a pre-trained model, Bert, and a spherical k-means clustering algorithm, and applies the similarity between literature and topics to assign literature to different topics. The proposed method was applied to 266 pieces of literature related to geospatial data over the past five years. First, according to the number of publications, the trend analysis of technologies and applications related to geospatial data in several leading countries was conducted. Then, the consistency of the proposed method and the existing method PLSA (Probabilistic Latent Semantic Analysis) was evaluated by using two similar consistency evaluation indicators (i.e., U-Mass and NMPI). The results show that the method proposed in this paper can well reveal text content, determine development trends, and produce more coherent topics, and that the overall performance of Bert-LSA is better than PLSA using NPMI and U-Mass. This method is not limited to trend analysis using the data in this paper; it can also be used for the topic analysis of other types of texts.