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971.
972.
采用高温燃烧法测定了夏季珠江口的溶解有机碳(dissolved organic carbon,DOC)浓度,结果表明,DOC浓度在夏季珠江口虎门上游不同来源的淡水水体间存在较大差异,广州段水体DOC浓度高达479 μmol/L,在广州-虎门约70 km干流中DOC浓度呈快速降低趋势。东江三条支流在广州-虎门汇入干流中,东江各支流平均DOC浓度约为227 μmol/L,东江DOC浓度相对较低水体的汇入稀释了干流中的DOC,再加上DOC的去除效应,至虎门时干流中DOC浓度只有139 μmol/L,即干流中DOC下降的浓度为340 μmol/L。建立三端元混合模型定量讨论去除效应和稀释效应各自的贡献,结果表明去除效应和稀释效应的贡献分别为228 μmol/L(占比约67%)和112 μmol/L(占比约33%),DOC浓度在珠江广州-虎门快速下降主要由去除效应造成,但东江对干流的稀释效应也不可忽略。 相似文献
973.
“热水解-高温厌氧消化”工艺处理高含固率剩余污泥的中试研究 总被引:5,自引:3,他引:2
采取热水解(70℃)-高温厌氧消化工艺处理高固含率(8%~9%)的剩余污泥(中试).该工艺利用SRT为3 d的热水解促进细胞溶解以及高温厌氧消化加快污泥消化速率,有机物去除能力较强,并获得了较好的污泥稳定化效果.当厌氧消化的SRT在20 d以上时,总VSS去除率达到42.22%以上,且VSS去除率与厌氧消化的SRT呈线性正相关,相关系数达到0.915 3.在实际应用中,推荐高温厌氧消化的SRT为25 d.当停留时间接近时,本工艺与运行良好的传统污泥厌氧消化工程(含固率3%~5%)以及采用德国技术的高固消化工程的有机物去除率和甲烷产率相当. 相似文献
974.
微生物燃料电池(MFC)芯片因具有体积小、运行条件温和、产电稳定等优点而有可能成为一种新型的野外水环境监测系统中传感器供能方式.但目前采用纯菌种及贵重金属阳极构建的MFC芯片,不仅成本较高且纯菌种在复杂环境条件下不易存活和保持稳定.因此,本文通过采用混合菌群接种,以活性炭为阳极,构建了阳极体积为50μL的MFC芯片,发现其稳定运行最大输出电流为3.5μA,平均运行周期为8.0 h,最大输出功率约为160 nW,最大功率密度为10.2 mW·m-2.EIS分析结果表明,MFC芯片的总内阻约为35.6 kΩ,其中,阴阳极内阻占主要部分.本研究制备的MFC芯片产电性能达到了同类采用纯菌株及Au作阳极的MFC芯片的性能,表明采用低成本材料为阳极,接种混合菌液的MFC芯片是完全可行的. 相似文献
975.
污泥深度机械脱水的优化研究 总被引:1,自引:0,他引:1
降低污泥含水率是污泥处置的关键点。论文自制了高压恒压污泥过滤脱水装置,在2 MPa压力条件下10 min可快速将污泥含水率降低至75.30%;添加3%氯化铁化学调理后,可进一步降低至63.38%。添加氯化铝调理也可降至71.98%;生物质添加剂也有较好的效果,污泥分别与木屑和秸秆按质量比2∶1调理后,压滤后污泥的含水率分别为60.22%和63.75%,木屑的效果优于秸秆;生物质还具有极强的吸水性,生物质与污泥混合泥饼压滤后表观含水率仅分别为43.83%与45.90%;此外,生物质调理后有助于提升污泥热值,可用于制备生物质污泥燃料。化学调理与生物质调理具有协同作用,优化后的污泥实际含水率及泥饼表观含水率低至55.23%与39.16%,污泥减量效果相当明显。 相似文献
976.
Yong Tang Yuanlong Huang Ling Li Hong Chen Jianmin Chen Xin Yang Song Gao Deborah S. Gross 《环境科学学报(英文版)》2014,26(12):2412-2422
Physical and chemical properties of ambient aerosols at the single particle level were studied in Shanghai from December 22 to 28, 2009. A Cavity-Ring-Down Aerosol Extinction Spectrometer(CRD-AES) and a nephelometer were deployed to measure aerosol light extinction and scattering properties, respectively. An Aerosol Time-of-Flight Mass Spectrometer(ATOFMS)was used to detect single particle sizes and chemical composition. Seven particle types were detected. Air parcels arrived at the sampling site from the vicinity of Shanghai until mid-day of December 25, when they started to originate from North China. The aerosol extinction,scattering, and absorption coefficients all dropped sharply when this cold, clean air arrived.Aerosol particles changed from a highly aged type before this meteorological shift to a relatively fresh type afterwards. The aerosol optical properties were dependent on the wind direction.Aerosols with high extinction coefficient and scattering Angstrom exponent(SAE) were observed when the wind blew from the west and northwest, indicating that they were predominantly fine particles. Nitrate and ammonium correlated most strongly with the change in aerosol optical properties. In the elemental carbon/organic carbon(ECOC) particle type, the diurnal trends of single scattering albedo(SSA) and elemental carbon(EC) signal intensity had a negative correlation. We also found a negative correlation(r =-0.87) between high mass-OC particle number fraction and the SSA in a relatively clean period, suggesting that particulate aromatic components might play an important role in light absorption in urban areas. 相似文献
977.
Microbial community structures in an integrated two-phase anaerobic bioreactor fed by fruit vegetable wastes and wheat straw 总被引:3,自引:0,他引:3
Chong Wang Jiane Zuo Xiaojie Chen Wei Xing Linan Xing Peng Li Xiangyang Lu Chao Li 《环境科学学报(英文版)》2014,26(12):2484-2492
The microbial community structures in an integrated two-phase anaerobic reactor(ITPAR)were investigated by 16 S r DNA clone library technology. The 75 L reactor was designed with a 25 L rotating acidogenic unit at the top and a 50 L conventional upflow methanogenic unit at the bottom, with a recirculation connected to the two units. The reactor had been operated for 21 stages to co-digest fruit/vegetable wastes and wheat straw, which showed a very good biogas production and decomposition of cellulosic materials. The results showed that many kinds of cellulose and glycan decomposition bacteria related with Bacteroidales,Clostridiales and Syntrophobacterales were dominated in the reactor, with more bacteria community diversities in the acidogenic unit. The methanogens were mostly related with Methanosaeta, Methanosarcina, Methanoculleus, Methanospirillum and Methanobacterium; the predominating genus Methanosaeta, accounting for 40.5%, 54.2%, 73.6% and 78.7% in four samples from top to bottom, indicated a major methanogenesis pathway by acetoclastic methanogenesis in the methanogenic unit. The beta diversity indexes illustrated a more similar distribution of bacterial communities than that of methanogens between acidogenic unit and methanogenic unit. The differentiation of methanogenic community composition in two phases, as well as pH values and volatile fatty acid(VFA) concentrations confirmed the phase separation of the ITPAR. Overall, the results of this study demonstrated that the special designing of ITPAR maintained a sufficient number of methanogens, more diverse communities and stronger syntrophic associations among microorganisms, which made two phase anaerobic digestion of cellulosic materials more efficient. 相似文献
978.
979.
980.
本文通过分析污泥中重金属的含量及存在形态,探讨了厌氧消化过程中重金属的形态转化极其去除方法。结果表明生物稳定法和药剂稳定法是目前最有效的方法。不但可降低污泥中重金属的生物有效性,而且不影响污泥农用化。 相似文献