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971.
有机固体废物堆肥化处理的微生物学机理研究   总被引:9,自引:0,他引:9  
由于符合持续发展的理念 ,利用微生物技术处理有机固体废物越来越受到人们的重视 ,其核心问题则是木质纤维素的生物降解。随着园林废物等高木质纤维素含量的城市生活垃圾的不断增加 ,以及对农业固体废物和食品工业废物再利用的需要 ,这一领域的研究取得了很大的进展。在研究中 ,针对好氧堆肥和厌氧发酵 2项主要的微生物处理技术 ,对其优势微生物菌群、不同降解底物和微生物降解动力学方面的最新研究进展进行了回顾和总结 ,并对环境微生物制剂的应用以及有机固体废物的微生物处理技术的发展做了合理的展望。  相似文献   
972.
● Medium poly Al salts dominated the PAC residual salts with a rational dosage. ● Settlement flocculation effect under medium poly Al salts showed a better trend. ● Complex of medium poly Al salts and enzymes promoted cell activity. ● Medium poly Al salts were beneficial to the effluent indexes. With the widespread introduction of pre-coagulation prior to the biological unit in various industrial wastewater treatments, it is noteworthy that long-term accumulation of residual coagulants has certains effect on both micro and macro characteristics of activated sludge (AS). In this study, the morphology distributions of residual aluminum salts (RAS) and their effects on the removal efficiency of AS were investigated under different PAC concentrations. The results showed that the dominance of medium polymeric RAS, formed under an appropriate PAC dose of 20 mg/L enhanced the hydrophobicity, flocculation, and sedimentation performances of AS, as well as the enzymatic activity in cells in the sludge system, improving the main pollutants removal efficiency of the treatment system. Comparatively the species composition with monomer and dimer / high polymer RAS as the overwhelming parts under an over-dosed PAC concentration of 55 mg/L resulted in excessive secretion of EPS with loose flocs structure and conspicuous inhibition of cellular activity, leading to the deterioration of physico-chemical and biological properties of AS. Based on these findings, this study can shed light on the role of the RAS hydrolyzed species distributions, closely relevant to Al dosage, in affecting the comprehensive properties of AS and provide a theoretical reference for coagulants dosage precise control in the pretreatment of industrial wastewater.  相似文献   
973.
● A new adsorption-membrane separation strategy is used for phosphate removal. ● PVC/Zr-BT shows a selective adsorption ability to low-concentration phosphate. ● Low concentration of P below 0.05 mg/L was achieved in actual wastewater treatment. ● Algal biomass production served as a demonstration of phosphorus recycling. Enhanced phosphorus treatment and recovery has been continuously pursued due to the stringent wastewater discharge regulations and a phosphate supply shortage. Here, a new adsorption-membrane separation strategy was developed for rational reutilization of phosphate from sea cucumber aquaculture wastewater using a Zr-modified-bentonite filled polyvinyl chloride membrane. The as-obtained polyvinyl chloride/Zr-modified-bentonite membrane was highly permeability (940 L/(m2·h)), 1–2 times higher than those reported in other studies, and its adsorption capacity was high (20.6 mg/g) when the phosphate concentration in water was low (5 mg/L). It remained stable under various conditions, such as different pH, initial phosphate concentrations, and the presence of different ions after 24 h of adsorption in a cross-flow filtration system. The total phosphorus and phosphate removal rate reached 91.5% and 95.9%, respectively, after the membrane was used to treat sea cucumber aquaculture wastewater for 24 h and no other water quality parameters had been changed. After the purification process, the utilization of the membrane as a new source of phosphorus in the phosphorus-free f/2 medium experiments indicated the high cultivability of economic microalgae Phaeodactylum tricornutum FACHB-863 and 1.2 times more chlorophyll a was present than in f/2 medium. The biomass and lipid content of the microalgae in the two different media were similar. The innovative polyvinyl chloride/Zr-modified-bentonite membrane used for phosphorus removal and recovery is an important instrument to establish the groundwork for both the treatment of low concentration phosphate from wastewater as well as the reuse of enriched phosphorus in required fields.  相似文献   
974.
针对车89井区的高含硫问题,新疆油田研究出化学除硫、负压闪蒸除硫和催化曝气除硫技术以及相关的配套工艺,并成功进行了现场试验;同时,为杜绝在车89井区环境敏感区域内污染事故的发生,新疆油田加大内外环保宣传软硬件建设力度,并依据专业评价实施了一系列防控管理措施,达到了预防在先、技术在先、管理在先的工作目标。  相似文献   
975.
沉井加桩复合基础是一种结合沉井及群桩各自优点形成的新型跨江海桥梁深水基础型式。在复杂的江海环境下,基础将承受强风、波浪及地震等引起的水平动荷载作用,其水平动力特性研究是复合基础合理设计施工和推广应用的重要保证。基于动力Winkler模型分别提出了沉井加桩基础的频域非线性及时域非线性计算方法,并同有限元对比验证了简化方法的正确性。通过算例进一步分析了冲刷对沉井加桩基础动力特性的影响规律,结果表明,土体应力历史及土体非线性对复合基础动力阻抗、共振幅值及频率均有显著影响。  相似文献   
976.
Enrichment of volatile organic compounds(VOC) and semi-volatility organic compounds(SVOC) in surface microlayer(SM) of three ddnking water sources were studied. The enrichment factor(EFs) were 0.67 to 13.37 and 0.16 to 136, respectively. The results showed some VOC and most SVOC could enrich in SM. Some EFs of SVOC was quite high. Suspension and temperature could affect EFs of SVOC, slim wind and water movement do not destroy enrichment of organic in SM.  相似文献   
977.
Effects of pesticides on soil biochemical characteristics of a paddy soil   总被引:4,自引:1,他引:3  
IntroductionThemaintenanceofsoilfertilitydependsonthesizeandtheactivityofthesoilmicrobialbiomasswhichisoffundamentalimportanceinbiologicalcyclesofalmostallmajorplantnutrients(Robert,1992 ) .Thereisconsiderableinterestinstudyofsoilbiochemicalcharacteristic…  相似文献   
978.
The contents of eight trace elements(Mn, Cr, Pb, As, Se, Zn, Cd, Hg) in raw coal, bottom ash and fly ash were measured in a 220 t/h pulverized coal boiler. Factors affecting distribution of trace elements were investigated, including fly ash diameter, furnace temperature, oxygen content and trace elements‘ characters. One coefficient of Meij was also improved to more directly show element enrichment in combustion products. These elements may be classified into three groups according to their distribution: Group 1. Hg, which is very volatile. Group 2: Pb, Zn, Cd, which are partially volatile. Group 3: Mn, which is hardly volatile. Se may be located between groups 1 and 2. Cr has properties of both group ! and 3. In addition, the smaller diameter of fly ash, the more relative enrichment of trace elements (except Mn). The fly ash showed different adsorption mechanisms of trace elements and the volatilization of trace elements rises with furnace temperature. Relative enrichments of trace elements(except Mn and Cr) in fly ash are larger than that in bottom ash. Low oxygen content can not always improve the volatilization of trace elements. Pb is easier to form chloride than Cd during coal combustion. Trace elements should be classified in accordance with factors.  相似文献   
979.
Kinetics of aniline oxidation with chlorine dioxide   总被引:4,自引:0,他引:4  
For the first time, kinetics of aniline oxidation with chlorine dioxide(ClO2) were investigated systematically by detecting concentration of aniline with HPLC at regular intervals. Results showed that the reaction was first-order both in ClO2 and in aniline, and the oxidation reaction could be described as second-order reaction. Stoichiometric factor η was experimentally determined to be 2.44. The second-order-reaction rate constant k was 0.11L/(mol.s)under condition of pH 6.86 and water temperature(Tw) 287K. Reaction activation energy was 72.31 kJ/mol, indicating that the reaction could take place under usual water treatment conditions. The reaction rate constants in acidic and alkali media were greater than that in neutral medium. Chlorite ion could slightly increase reaction rate in acidic medium. p-aminophenol and azobenzene were detected by GC-MS as intermediates.  相似文献   
980.
在生态县规划研究中,以复合生态系统理论为指南,探讨了生态县的内涵和评价标体系,并确定了以生态农业为基础,以生态型工业为主导,以社会调控为保障,依靠科技进步,寓环境建设于经济社会发展之中的建设生态县的战略,在近年实践中初见成效。  相似文献   
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