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91.
为实现污水厂污泥及余泥渣土的协同处理和资源化利用,以“两步法”制备人工土壤,考察不同配比条件对人工土壤理化性质的影响。结果表明:污水污泥与3种不同辅料 (玉米秸秆、菌菇渣、木屑) 配比后进行好氧堆肥,堆肥结束后腐熟度符合国家相关标准要求,将污泥堆肥产物和余泥渣土制备得到人工土壤,其理化性质与天然土壤类似。堆肥添加量能显著影响人工土壤水稳性团聚体、pH值、EC、有机质、总氮及有效磷含量,在人工土壤种植应用时,污泥+玉米秸秆的堆肥种植效果最好,采用改进的内罗梅综合指数法进行综合评价,综合考虑,污泥+玉米秸秆堆肥产物添加量为30%、余泥渣土添加量为70%和污泥+玉米秸秆堆肥产物添加量为50%、余泥渣土添加量为50%是最优质的人工土壤,污泥+木屑堆肥次之,污泥+菌菇渣堆肥效果最差。 相似文献
92.
Lü Z Min H Li N Shao T Ye Y 《Journal of environmental science and health. Part. B》2006,41(6):821-832
The denaturing gradient gel electrophoresis (DGGE) method was applied to determine the relative genetic complexity of microbial communities in flooded paddy soil treated with herbicide quinclorac (3,7-dichloro-8-quinoline-carboylic acid). The results obtained showed a significant effect of quinclorac on the development of bacterial populations in soils contaminated with different concentrations of the herbicide at the early time after application. In general, however, the number of populations of the same soil sample treated with the same concentration of the quinclorac differed obviously with increasing incubation time within the early 8 weeks. The scale of differences in banding patterns-showed that the microbial community structures of the quinclorac-treated and non-quinclorac-treated soils were not significantly different after 21 weeks of incubation. Quantification, as demonstrated in this paper, was studied by establishing dose-response relationships. Significant pattern variations were quantified. Prominent DGGE bands were excised, cloned and sequenced to gain insight into the identities of predominant bacterial populations. The majority of DGGE band sequences were related to bacterial genera Clostridium, Sphingobacterium, Xanthomonas and Rhodococcus. 相似文献
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94.
Min Qin Pinhua Xie Hang Su Jianwei Gu Fumin Peng Suwen Li Limin Zeng Jianguo Liu Wenqing Liu Yuanhang Zhang 《Atmospheric environment (Oxford, England : 1994)》2009,43(36):5731-5742
The temporal behavior of HONO and NO2 was investigated at an urban site in Guangzhou city, China, by means of a DOAS system during the Pearl River Delta 2006 intensive campaign from 10 to 24 July 2006. Within the whole measurement period, unexpected high HONO mixing ratios up to 2 ppb were observed even during the day. A nocturnal maximum concentration of about 8.43 ± 0.4 ppb was detected on the night of 24 July 2006. Combining the data simultaneously observed by different instruments, the coupling of HONO–NO2 and the possible formation sources of HONO are discussed. During the measurement period, concentration ratios of HONO to NO2 ranged from (0.03 ± 0.1) to (0.37 ± 0.09), which is significantly higher than previously reported values (0.01–0.1). Surprisingly, in most cases a strong daytime correlation between HONO and NO2 was found, contrary to previous observations in China. Aerosol was found to have a minor impact on HONO formation during the whole measurement period. Using a pseudo steady state approach for interpreting the nocturnal conversion of NO2 to HONO suggests a non-negligible role of the relative humidity for the heterogeneous HONO formation from NO2. 相似文献
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97.
Oh CJ Lee SO Yang HS Ha TJ Kim MJ 《Journal of the Air & Waste Management Association (1995)》2003,53(7):897-902
This study was carried out to recover valuable metals from the printed circuit boards (PCBs) of waste computers. PCB samples were crushed to smaller than 1 mm by a shredder and initially separated into 30% conducting and 70% nonconducting materials by an electrostatic separator. The conducting materials, which contained the valuable metals, were then used as the feed material for magnetic separation, where it was found that 42% of the conducting materials were magnetic and 58% were nonmagnetic. Leaching of the nonmagnetic component using 2 M H2SO4 and 0.2 M H2O2 at 85 degrees C for 12 hr resulted in greater than 95% extraction of Cu, Fe, Zn, Ni, and Al. Au and Ag were extracted at 40 degrees C with a leaching solution of 0.2 M (NH4)2S2O3, 0.02 M CuSO4, and 0.4 M NH4OH, which resulted in recovery of more than 95% of the Au within 48 hr and 100% of the Ag within 24 hr. The residues were next reacted with a 2 M NaCl solution to leach out Pb, which took place within 2 hr at room temperature. 相似文献
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99.
Linglong Wang Haochang Su Xiaojuan Hu Yu Xu Wujie Xu Xiaoshuai Huang 《Journal of environmental science and health. Part. B》2019,54(3):211-218
Although research regarding antibiotic resistance genes (ARGs) in aquaculture environments has gained increasing scientific interest, further studies are required to understand the abundances and removal mechanisms of ARGs during the entire rearing period of shrimp aquaculture. Thus, in this study, abundances, distributions and removal rates of ARGs in different environmental compartments of intensive shrimp farms in South China were investigated during the entire rearing period. The results indicated that sul1 and cmlA were the predominant ARGs in the water and sediment samples. Additionally, the total abundance of ARGs was higher in shrimp pond water than in the source water and farm effluent. Moreover, sediment samples indicated significantly higher ARG abundances than water samples from the shrimp ponds (P?<?0.05). Environmental factors were found to significantly affect the distribution of ARGs in shrimp rearing environments. Furthermore, stable ponds aided the removal of ARGs from shrimp pond water. This study accounted for temporal variations in ARG abundances as well as removal of ARGs in different environmental compartments during the entire shrimp rearing period. However, additional research is required to optimize the water treatment process for removal of ARGs from the aquaculture. 相似文献
100.
考察了臭氧氧化对林可霉素的效价削减效果。在初始抗生素浓度为100 mg·L−1时,林可霉素效价削减50%所需消耗的臭氧量为0.118 mg·mg−1抗生素,降解过程符合一级降解动力学特征。进一步采用林可霉素实际废水考察了污水化学需氧量(COD)和pH对抗生素臭氧氧化处理的影响,发现废水的COD每增加100 mg·L−1,则单位抗生素实现50%削减需要增加的臭氧量约为1.64 mg。碱性条件下,臭氧可催化分解生成羟基自由基等活性基团而加速林可霉素的降解。同时,臭氧氧化后林可霉素生产废水的厌氧可生化性提高了98.51%。研究结果可以为林可霉素生产废水的处理技术选择提供参考。 相似文献