Water Conservation and Ecological Water Requirement Prediction of Mining Area in Arid Region Based on RS-GIS and InVEST: A Case Study of Bayan Obo Mine in Baotou, China

Abstract

The overexploitation of mineral resources in northwestern China has resulted in severe ecological degradation and even desertification in certain mining areas. To support ecological restoration in these arid mining regions, we conducted a study on water conservation and ecological water demand using Bayan Obo as a case study. Based on remote sensing, geographic information systems, and the Integrated Valuation of Ecosystem Services and Trade-offs InVEST model, our study found that the mining area has lost its capacity for water production, with the water source conservation showing negative values. In addition, precipitation levels are far lower than evapotranspiration, making it difficult to retain precipitation. We predicted ecological water demand for the planning years (2025, 2030, and 2035) by combining qualitative and quantitative forecasting methods, with 2019 serving as the base year. The results indicated a downward trend in natural ecological water demand, while artificial ecological water demand exhibited the opposite trend. Changes in natural grassland and artificial green areas in the mining region were identified as the main drivers of changes in ecological water demand.

Microorganism-mediated denitrogenation of aquaculture systems provoked by poly-β-hydroxybutyrate (PHB)

“…Notably, the experimental group had a significantly higher number of attached microorganisms compared to the control group. Previous studies have indicated that the main dominant bacterial groups involved in denitrification include Proteobacteria, Firmicutes, Bacteroides, and Actinomyces [22][23][24] . It is worth noting that these dominant denitrifying bacteria are predominantly rod-shaped and filamentous, which aligns with the SEM observations in the present study.…”

“…The largemouth bass (Micropterus salmoides) is a carnivorous species that requires a diet with a high protein content of 50%, yet it exhibits a relatively low feed conversion efficiency of 20-30% 23 . Biological nitrogen removal by polyamide elastic filler has been shown to effectively reduce the nitrogen and phosphorus discharges in wastewater from largemouth bass culture 24 . Nevertheless, the efficacy of employing PHB as a sustainable substrate for biological denitrification in the lowcarbon-to-nitrogen ratio wastewater from largemouth bass aquaculture remains to be fully elucidated.…”