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Lei Shen Yuntao Guan Guangxue Wu Xinmin Zhan 《Frontiers of Environmental Science & Engineering》2014,8(5):776-783
Nitrous oxide (N2O) is a greenhouse gas that can be released during biological nitrogen removal from wastewater. N2O emission from a sequencing batch reactor (SBR) for biological nitrogen and phosphorus removal from wastewater was investigated, and the aims were to examine which process, nitrification or denitrification, would contribute more to N2Oemission and to study the effects of heterotrophic activities on N2O emission during nitrification. The results showed that N2O emission was mainly attributed to nitrification rather than to denitrification. N2O emission during denitrification mainly occurred with stored organic carbon as the electron donor. During nitrification, NaO emission was increased with increasing initial ammonium or nitrite concentrations. The ratio of N2O emission to the removed ammonium nitrogen (N2O- N/NH4-N) was 2.5% in the SBR system with high heterotrophic activities, while this ratio was in the range from 0.14% to 1.06% in batch nitrification experiments with limited heterotrophic activities. 相似文献
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山谷型垃圾填埋场渗沥液水量计算方法比较研究 总被引:6,自引:0,他引:6
山谷型垃圾填埋场渗沥液水量是工程设计中的一个重要基础参数,主要由场内降雨转化为场外地下径流组成。对于场外地下径流,目前国内外尚无成熟的计算方法。作者针对几种常用的水量平衡法,通过实验,验证了每种方法的精度。结果表明,考虑了树冠戴流、表层土调蓄作用等因素的模型具有相当的精度,可以作为场外地下径流的计算模型。 相似文献
456.
Sijia Ai Hongyu Liu Mengjie Wu Guangming Zeng Chunping Yang 《Frontiers of Environmental Science & Engineering》2018,12(6):3
Three acid-producing strains, AFB-1, AFB-2 and AFB-3, were isolated during this study, and their roles in anaerobic digestion of waste activated sludge (WAS) were evaluated. Data of 16S rRNA method showed that AFB-1 and AFB-2 were Bacillus coagulans, and AFB-3 was Escherichia coli. The removal in terms of volatile solids (VS) and total chemical oxygen demand (TCOD) was maximized at 42.7% and 44.7% by inoculating Bacillus coagulans AFB-1. Besides, the optimal inoculum concentration of Bacillus coagulans AFB-1 was 30% (v/v). Solubilization degree experiments indicated that solubilization ratios (SR) of WAS reached 20.8%±2.2%, 17.7%±1.48%, and 11.1%±1.53%. Volatile fatty acids (VFAs) concentrations and compositions were also explored with a gas chromatograph. The results showed that VFAs improved by 98.5%, 53.0% and 11.6% than those of the control, respectively. Biochemical methane potential (BMP) experiments revealed that biogas production increased by 90.7% and 75.3% when inoculating with Bacillus coagulans AFB-1 and AFB-2. These results confirmed that the isolated acid-producing bacteria, especially Bacillus coagulans, was a good candidate for anaerobic digestion of WAS.
相似文献
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以68台燃油锅炉(≤10~MW)NOx排放实测数据为基础,通过统计分析方法,研究了NOx的排放特征;通过对比分析,探讨了我国燃油锅炉NOx排放控制与管理现状,讨论了进一步加强我国燃油锅炉NOx排放管理控制的可能性与可行性,并提出了相应的管理控制建议。结果表明,NOx平均排放浓度为318.2mg/m^3,基于燃料消耗量的平均排放因子为4.4kg/t,基于燃料发热量的平均排放因子为102.8ng/J,基于燃料氮含量的平均排放因子为2.1mg/mg;建议采取分阶段控制的方式,逐步提高NOx排放限制,从而实现控源减排目标。 相似文献
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利用正交试验方法优化了净化烹饪油污菌种选育的环境和营养条件 ,即 :油 :2 0mL、NaNO3( 2g L) :4mL、KH2 PO4( 0 .5g L) :3mL、微量元素溶液 (CuSO4·5H2 O 0 .0 3g L ,ZnSO4·7H2 O 0 .1g L ,MnCl2 ·4H2 O 0 .0 5g L) :1mL和温度 3 7℃ ;而且得出氮源是影响菌体增长的最重要因素 ,温度是影响微生物降解的重要因素 ,而微量元素和磷源对菌种培育结果影响较小。在此优化条件下选育出了合适降解烹饪油污的c种子菌液 ,其每天可降解油 2 2mg L以上 ,并鉴定出主要的微生物是嗜水性气单孢菌 (Aeromonashydrophila 4AK4)、黄丝藻属 (Tribonema)和多甲藻属 (Peridinium)等菌体 ;分析了选育过程活性微生物、目标污染物和微生物的代谢产物三者之间的关系 ,发现所选微生物能利用油类物质作为碳源进行生长代谢 相似文献
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Yangyang Wang Zhihui Yang Bing Peng Liyuan Chai Baolin Wu Ruiping Wu 《Environmental science and pollution research international》2013,20(8):5593-5602
Chromite ore processing residues (COPR) is the source of the Cr(VI) contamination in the environment. Pannonibacter phragmitetus BB was used to treat two different types of COPRs in this research. The water-soluble Cr(VI) of COPR A and B is 3,982.9 and 1,181.4 mg/kg, respectively. In the column biotreatment process, P. phragmitetus BB can reduce Cr(VI) in the leachate to an undetectable level at the flow rate of 1 and 2 ml/min. In the direct biotreatment process, Cr(VI) in the liquid supernatant of COPR A and B decreased from 265 and 200 mg/l to 145 and 40 mg/kg after 240 h of incubation. In one-step and two-step biotreatment processes, Cr(VI) in the liquid supernatant of both COPRs can be reduced to an undetectable level. The toxicity characteristic leaching procedure results indicate that the Cr(VI) concentration of treated COPR A (3.48 mg/l) is lower than the identification standards for hazardous wastes of China (5 mg/l) (GB 5085.6-2007). The information obtained in this study has significance for the application of P. phragmitetus BB to remediate COPR contamination. 相似文献