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981.
Yanan Yin Chao Yang Jingrui Tang Jie Gu Haichao Li Manli Duan Xiaochang Wang Rong Chen 《环境科学学报(英文版)》2021,33(10):84-95
Microbial enzymes are crucial for material biotransformation during the composting process. In this study, we investigated the effects of adding bamboo charcoal (BC) (i.e., at 5%, 10%, and 20% corresponding to BC5, BC10, and BC20, respectively) on the enzyme activity levels during chicken manure composting. The results showed that BC10 could increase the cellulose and urease activities by 56% and 96%, respectively. The bacterial community structure in BC10 differed from those in the other treatments, and Luteivirga, Lactobacillus, Paenalcaligenes, Ulvibacter, Bacillus, Facklamia, Pelagibacterium, Sporosarcina, Cellvibrio, and Corynebacterium had the most important roles in composting. Compared with other treatments, BC10 significantly enhanced the average rates of degradation of carbohydrates (D-xylose (40%) and α-D-lactose (44%)) and amino acids (L-arginine (16%), L-asparagine (14%), and L-threonine (52%)). We also explored the associations among the bacterial community and their metabolic functions with the changes in the activities of enzymes. Network analysis demonstrated that BC10 altered the co-occurrence patterns of the bacterial communities, where Ulvibacter and class Bacilli were the keystone bacterial taxa with high capacities for degrading carbon source, and they were related to increases in the activities of cellulase and urease, respectively. The results obtained in this study may help to further enhance the efficiency of composting. 相似文献
982.
为了研究高边坡紫色土的抗剪强度及变形随含水率的变化规律,在不同围压下对不同含水率的非饱和重塑紫色土进行了固结不排水三轴试验。结果表明:在不同的含水率及围压条件下,土体应力-应变关系曲线均呈现出“持续硬化”甚至“加速硬化”现象。其应力-应变关系曲线经历了3个阶段:轴向应变0%~2.3%为弹性阶段,2.3%~4%为应变硬化阶段,4%后逐渐变为屈服阶段。在同一围压下,土体主应力差峰值随含水率的增加而降低,其峰值下降幅度最大可达67.37%。不同含水率下的最大主应力差与围压均表现出较好的线性关系。在给定含水率下,主应力差峰值随围压的增加而明显增大,其峰值增大幅度最大可达150.98%,但随着含水率的升高,这种增大趋势逐渐减小,且围压对紫色土抗剪强度影响约为含水率对其影响的66.63%。随着含水率的增加,土壤的内聚力先增加后减小,峰值处的含水率为12%;而土壤的内摩擦角随含水率的增加呈现一阶线性减小,且下降程度最大可达56.88%。土体任意平面(破坏面)上σ-τ曲线的斜率随着含水率的增加而逐渐减小,而破坏包面逐渐变缓。分析并讨论了含水率对紫色土内部结构、颗粒间作用力及特性的影响,以期为三峡库区高边坡紫色土的综合治理提供理论支持和技术支撑。 相似文献
983.
984.
针对宁夏电网 220 kV 及以上部分线路保护信号传输通道配置存在的问题,按照“国家电网公司十八项电网重大反事故措施”具体要求对其进行了详细分析,并提出了相应的优化策略。应用结果表明:该优化策略体现了线路保护信号传输通道的有效性和合理性,使其安全可靠性得到显著提升 相似文献
985.
研究了新试剂二安替比林邻烯丙氧基本基甲烷(DAoPM)与钻(Ⅵ)的显色反应,在磷酸介质中,Mn(Ⅱ)存在下,DAoPM和铬(Ⅵ)生成橙色产物,λmax=480nm,ε=3.53×105L·mol-1·cm-1。铬(Ⅵ)含量在0~100μg/L内符合比耳定律.方法用于环境水样中铬(Ⅵ)和总铬的测定,结果满意。 相似文献
986.
987.
Yin Ting Zhu Xu Cheang Iokfai Zhou Yufei Liao Shengen Lu Xinyi Zhou Yanli Yao Wenming Li Xinli Zhang Haifeng 《Environmental science and pollution research international》2023,30(10):25093-25102
Environmental Science and Pollution Research - The field of environmental health has begun to examine the effects of higher-order chemical combinations. The current literature lacks studies... 相似文献
988.
嗜热栖热菌降解氟喹诺酮类抗生素 总被引:1,自引:0,他引:1
氟喹诺酮类抗生素在各种环境基质中积累造成的生态和耐药基因污染等问题已引起广泛的关注。为了能够有效去除环境中氟喹诺酮类抗生素污染并且探究其生物代谢途径,利用嗜热菌Thermus sp. C419在高温(70℃)条件下降解2种典型的氟喹诺酮类抗生素(诺氟沙星和恩诺沙星),分析了菌株C419对这2种药物在单一和混合添加时的降解特性;通过UPLC-MS/MS检测了其相关的降解产物,并推测了可能的代谢途径;利用平板扩散法对生物降解后的氟喹诺酮类药物进行抑菌活性测定。结果表明:氟喹诺酮类化合物可被菌株C419有效降解,降解率为60%~80%;该生物降解过程符合一级动力学模型,培养基中氟喹诺酮类化合物浓度越高,降解率越高,降解半衰期越短;菌株C419对诺氟沙星的生物降解有3条可能的降解途径和7种降解产物,对恩诺沙星的生物降解有4条可能的降解途径和6种降解产物。此外,与2种药物的母体化合物相比,生物降解后药物对不同细菌的抗菌活性均有一定程度的降低,这说明嗜热菌株C419在热环境中去除氟喹诺酮类污染物方面可能会具有良好的实用性和应用前景。 相似文献
989.
Ruiwei Xu Zhen Zhang Liping Wang Ningning Yin Xiaohui Zhan 《Environmental science and pollution research international》2018,25(15):14437-14446
This study evaluated the effects of two surfactants (i.e., Tween 80 and SDS) on biodegradation of crude oil by mixed bacterial consortium in soil-aqueous system. The mixed bacterial consortium was domesticated from the activated sludge of cooking plant through a progressive domestication process. High-throughput sequencing analysis revealed that Rhodanobacter sp. was the dominant bacteria. The higher CMCeff value for two surfactants was observed in soil-aqueous system compared with that in aqueous system, which was likely due to their adsorption onto soil particles. Either Tween 80 or SDS can be utilized as carbon source and promote the growth of mixed bacterial consortium. Further findings evidenced that the degradation of crude oil can be enhanced by adding either Tween 80 or SDS. The performance of Tween 80 was generally superior to SDS for the crude oil degradation. The highest crude oil degradation efficiency was 42.2 and 31.0% under the conditions of 5 CMCeff of Tween 80 and 2 CMCeff of SDS, respectively. Furthermore, the degradation efficiency of crude oil in remediation experiment (i.e., 77%) evidenced that the integration of adding Tween 80 and inoculating mixed bacterial consortium was effective for crude oil-contaminated soil decontamination. 相似文献
990.
Effects of biofilter media depth and moisture content on removal of gases from a swine barn 总被引:1,自引:0,他引:1
Tongshuai Liu Zhiping Zhu Bin Shang Fubin Yin Wanqin Zhang 《Journal of the Air & Waste Management Association (1995)》2017,67(12):1288-1297
Media depth (MD) and moisture content (MC) are two important factors that greatly influence biofilter performance. The purpose of this study was to investigate the combined effect of MC and MD on removing ammonia (NH3), hydrogen sulfide (H2S), and nitrous oxide (N2O) from swine barns. Biofiltration performance of different MDs and MCs in combination based on a mixed medium of wood chips and compost was monitored. A 3 × 3 factorial design was adopted, which included three levels of the two factors (MC: 45%, 55%, and 67% [wet basis]; MD: 0.17, 0.33, and 0.50 m). Results indicated that high MC and MD could improve NH3 removal efficiency, but increase outlet N2O concentration. When MC was 67%, the average NH3 removal efficiency of three MDs (0.17, 0.33, and, 0.50 m) ranged from 77.4% to 78.7%; the range of average H2S removal efficiency dropped from 68.1–90.0% (1–34 days of the test period) to 36.8–63.7% (35–58 days of the test period); and the average outlet N2O concentration increased by 25.5–60.1%. When MC was 55%, the average removal efficiency of NH3, H2S, and N2O for treatment with 0.33 m MD was 72.8 ± 5.9%, 70.9 ± 13.3%, and –18.9 ± 8.1%, respectively; and the average removal efficiency of NH3, H2S, and N2O for treatment with 0.50 m MD was 77.7 ± 4.2%, 65.8 ± 13.7%, and –24.5 ±12.1%, respectively. When MC was 45%, the highest average NH3 reduction efficiency among three MDs was 60.7% for 0.5 m MD, and the average N2O removal efficiency for three MDs ranged from –18.8% to –12.7%. In addition, the pressure drop of 0.33 m MD was significantly lower than that of 0.50 m MD (p < 0.05). To obtain high mitigation of NH3 and H2S and avoid elevated emission of N2O and large pressure drop, 0.33 m MD at 55% MC is recommended.
Implications: The performances of biofilters with three different media depths (0.17, 0.33, and 0.50 m) and three different media moisture contents (45%, 55%, and 67% [wet basis]) were compared to remove gases from a swine barn. Using wood chips and compost mixture as the biofilters media, the combination of 0.33 m media depth and 55% media moisture content is recommended to obtain good reduction of NH3 and H2S, and to simultaneously prevent elevated emission of N2O and large pressure drop across the media. 相似文献