污染密集型企业区域迁移后的环境行为分析

在国家主体功能区规划和区域经济发展战略的共同推动下,大量污染密集型企业从东部沿海向中西部地区迁移。中西部地区如何实现经济发展和生态环境保护的双赢,迁移企业的环境行为改善成为问题的关键。本文以江西省G市H电源公司为案例,研究迁移企业环境行为改善的阶段特征,分析各利益相关者的相互作用以及企业响应,探讨促进企业环境行为改善的驱动机制。研究发现,迁移企业的环境行为优化和环境绩效提高不是自发的,是各利益相关者多次博弈的过程。在这个过程中,严格的环境规制和民众环保意识的提高是重要的推动因素;地方政府具有执行环境规制和追求经济增长的双重角色,使迁移企业环境行为的改善进程更加复杂,污染密集型企业的可持续发展需要新的思路。在案例研究的基础上,本文试图探索中西部地区实现经济发展与生态环境保护双赢的路径,为实现中国经济的绿色转型和升级提供有益的借鉴和参考。     

Improvement of aquaculture water quality by mixed Bacillus and its effects on microbial community structure

Microbial remediation, especially the application of probiotics, has recently gained popularity in improving water quality and maintaining aquatic animal health. The efficacy and mechanism of mixed Bacillus for improvement of water quality and its effects on aquatic microbial community structure remain unknown. To elucidate these issues, we applied two groups of mixed Bacillus (Bacillus megaterium and Bacillus subtilis (A0?+?BS) and Bacillus megaterium and Bacillus coagulans (A0?+?BC)) to the aquaculture system of Crucian carp. Our results showed that the improvement effect of mixed Bacillus A0?+?BS on water quality was better than that of A0?+?BC, and the NH₄⁺-N, NO₂^?-N, NO₃^?-N, and total phosphorus (TP) concentrations were reduced by 46.3%, 76.3%, 35.6%, and 80.3%, respectively. In addition, both groups of mixed Bacillus increased the diversity of the bacterial community and decreased the diversity of the fungal community. Microbial community analysis showed that mixed Bacillus A0?+?BS increased the relative abundance of bacteria related with nitrogen and phosphorus removal, such as Proteobacteria, Actinobacteria, Comamonas, and Stenotrophomonas, but decreased the relative abundance of pathogenic bacteria (Acinetobacter and Pseudomonas) and fungi (Epicoccum and Fusarium). Redundancy analysis showed that NH₄⁺-N, NO₂^?-N, and TP were the primary environmental factors affecting the microbial community in aquaculture water. PICRUST analysis indicated that all functional pathways in the A0?+?BS group were richer than those in other groups. These results indicated that mixed Bacillus A0?+?BS addition produced good results in reducing nitrogenous and phosphorus compounds and shaped a favorable microbial community structure to further improve water quality.

Graphical abstract