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1.
为实现污泥的无害化处理和资源化利用,本研究对污泥进行初步脱水和干化深度脱水,使含水率降到30%左右,干化后的污泥进行焚烧处理,在脱水滤液中加入Mg盐回收氮磷得到鸟粪石。结果显示:脱水滤液中调节镁/磷摩尔比为1.0~1.2时,可得到较多鸟粪石沉淀;烧结温度为900~1100℃,烧结时间为20~40min时,可得到环保性能优良的烧结体,将鸟粪石和污泥烧结体混合得到可用于园林绿化的植物栽培基质。  相似文献   

2.
以污泥、磷尾矿和赤泥为原料制备陶粒,用盐酸、硝酸和柠檬酸进行改性,研究陶粒对水中Pb2+的吸附效果,并通过扫描电镜(SEM)、表面基团、零电荷点(pHPZC)和傅里叶红外光谱(FTIR)分析陶粒对Pb2+的吸附机理。结果表明,低浓度盐酸或硝酸改性陶粒对Pb2+的去除率更好,柠檬酸改性陶粒对Pb2+的去除率低于未改性陶粒。酸改性陶粒具有比表面积大、孔隙结构发达、酸性基团含量多、等电点低等特点,对Pb2+的吸附同时存在物理吸附和化学吸附过程,可用作含Pb2+废水的处理材料。  相似文献   

3.
为系统研究厌氧污泥回流比对生物除磷效果的影响,本文以实际生活污水作为研究水样,研究不同污泥回流比下厌氧段对COD、N、P的去除效果,深入研究污泥回流比对生物强化除磷代谢过程的影响。结果表明,在厌氧环境中污泥回流比对NH3-N的去除没有明显影响,但对硝态氮、TP、COD的去除影响较大。最佳回流污泥比应控制在60%~80%左右,在这两个工况下,PAO释磷量能达到24.13mg/L,这样能使PAO在厌氧池有效地利用碳源,充分释磷,从而提高除磷效率,同时应控制最佳厌氧有效时间为2~3h,如果厌氧时间过长或者过短都对PAO释磷产生一定的负作用。  相似文献   

4.
采用统计学方法对新疆某污水处理厂A2/O工艺进行进水水质数据分析,发现数据存在严重自相关现象,运用主成分消除法和岭回归消除法以消除自相关性。结果表明:TN和TP是污水厂提标改造的关键;碳源匮乏和缺氧区存在溶解氧(DO)是TN去除不佳的主要原因;适当提高污泥浓度(MLSS)和水力停留时间(HRT)是强化TP去除的措施;温度是影响脱氮除磷的主要因素。将温度模型与自相关磷模型相结合,可提高磷模型精度,有利于出水TP的预测。降低DO、增加外碳源,控制MLSS为3 500 mg/L~4 500 mg/L、HRT为5.4 h~8.0 h、厌氧区和好氧区DO为0.3 mg/L和2 mg/L、污泥龄(SRT)为11 d~12 d,可提升工艺脱氮除磷效果。  相似文献   

5.
针对钢铁企业烧结工段烟气的特点,对可能影响碘量法、定电位电解法SO_2监测结果的因素进行分析,并提出相应的对策。研究表明:定电位电解法受CO干扰较大,根据数学模型修正后,可进行SO_2浓度的快速估算;碘量法受吸收液温度、分析时间等因素影响较大,需要现场监测人员和分析人员严格控制采样和分析条件。  相似文献   

6.
以某典型钢铁企业为研究对象,测定企业废气、废水、固废汞排放水平,并分析汞排放特征。研究表明,球团、烧结、高炉工艺废气排口烟尘中汞排放浓度和排放速率明显低于烟气;汞主要以气态形式排放,烧结工艺排口废气汞最高浓度分别是其他2个排口的7倍和3倍。球团、烧结、高炉、电炉四工艺环节中,烧结汞排放速率占四工艺汞排放速率总和的87%。半干法脱硫、氨法脱硫、石灰石石膏脱硫对废气中汞的去除效率分别为90.0%、78.7%和29.9%。企业废水排放未检出汞,脱硫产生固废汞含量明显高于除尘产生固废汞含量,脱硫灰汞含量是脱硫石膏的15倍。  相似文献   

7.
对臭氧氧化法污泥减量技术进行了试验研究。试验表明,污泥浓度和臭氧流量均会影响污泥减量效果。当SV%=40,Qo2=20L/h,氧污比为0.15gO3/gMLSS时,污泥去除率最高,达到67.95%,污泥浓度与时间的函数关系为:S=3209.60e-0.1428t(S—MLSS浓度,mg/L;e—指数常数t;—时间,h)。电镜观察表明,经过臭氧氧化,污泥菌胶团密度降低,丝状菌网状结构破坏,细胞质溶出,细胞量明显减少。臭氧氧化法污泥减量技术对于解决污泥问题具有指导意义。  相似文献   

8.
浅谈磷石膏的综合利用   总被引:8,自引:0,他引:8  
根据磷石膏作为湿法生产磷酸过程中的副产品,且含有少量的P2O5和氟等有害成分,是生产厂家面临的磷石膏的处理和再利用这一实际问题,论述了磷石膏的综合利用情况,为磷石膏的利用和开发提供了研究和参考的方向。  相似文献   

9.
以城市污水处理厂的脱水污泥为原料,通过超声波细胞破碎制备微生物絮凝剂。采用控制变量法考察污泥浓度、超声波破碎时间对絮凝剂絮凝效果的影响,并探究絮凝液的投加量、pH值、温度、振荡时间、振荡频率、共存金属等因素对5 mg/L Cu^2+模拟废水的去除效果,分析了微生物絮凝剂去除Cu^2+的作用机理。结果表明:当污泥质量浓度为100 g/L,超声波破碎时间15 min时,絮凝剂的絮凝效果最好;当pH值为6.5,温度50℃,絮凝液投加量40 mL,振荡时间1 min,振荡频率200 r/min时去除效果最佳。  相似文献   

10.
方法一 四氯汞钾吸收液—盐酸付玫瑰苯胺比色法 本法检测限为0.30μg SO_2/10ml。 一、仪器: 1.吸收瓶:75ml多孔玻板吸收瓶。 2.大气采样器:流量范围0~1L/min,湖北省环保仪器研究所生产的成套设备。 3.72分光光度计。 二、采样: 用一个内装50ml吸收液的多孔玻板吸收瓶,以0.2L/min流量,从8:00至次日8:00,采样时间24±0.5小时,采样体积约为288L。记录采样口的温度、压力。采样后,将样品带回实验室分析,或保存在冰箱里,一周后一起分析。  相似文献   

11.
Process integrated modelling for steelmaking Life Cycle Inventory analysis   总被引:1,自引:0,他引:1  
During recent years, strict environmental regulations have been implemented by governments for the steelmaking industry in order to reduce their environmental impact. In the frame of the ULCOS project, we have developed a new methodological framework which combines the process integrated modelling approach with Life Cycle Assessment (LCA) method in order to carry out the Life Cycle Inventory of steelmaking. In the current paper, this new concept has been applied to the sinter plant which is the most polluting steelmaking process. It has been shown that this approach is a powerful tool to make the collection of data easier, to save time and to provide reliable information concerning the environmental diagnostic of the steelmaking processes.  相似文献   

12.
介绍了二噁英在烧结过程中的生成机理;针对烧结烟气二噁英的生成及排放特点,对烧结过程二噁英的减排方法进行了分析;提出了从源头—过程—末端综合治理及多种污染物协同控制的建议。  相似文献   

13.
An important research area in life sciences is devoted to modeling, prediction, and dynamics of gene-expression patterns. As clearly understood in these days, this enterprise cannot become satisfactory without acknowledging the role of the environment. To a representation of past, present, and most likely future states, we also encounter measurement errors and uncertainties. This paper surveys and improves recent advances in understanding the foundations and interdisciplinary implications of the newly introduced gene–environment networks, and it integrates the important theme of carbon dioxide emission reduction into the networks and dynamics. We also introduce some operational and managerial issues of practical working and decision making, expressed in terms of sliding windows, quadrants (modules) of parametric effects, and navigating (controlling) between such effects and directing them. Given data from DNA microarray experiments and environmental records, we extract nonlinear ordinary differential equations that contain parameters that have to be determined. For this, we employ modern (Chebychevian) approximation and (generalized semi-infinite) optimization. After this is provided, time- discretized dynamical systems are studied. A combinatorial algorithm with polyhedra sequences allows to detect the region of parametric stability. Finally, we analyze the topological landscape of gene–environment networks with its structural (in)stability. By embedding as a module and investigating CO2 emission control and figuring out game theoretical aspects, we conclude. This pioneering work is theoretically elaborated, practically devoted to health care, medicine, education, living conditions, and environmental protection, and it invites the readers to future research.   相似文献   

14.
In this article a comprehensive approach for the evaluation of possible health effects in an environmental impact assessment (EIA) is described, illustrated with the example of Amsterdam Airport Schiphol. Unlike many EIAs, we estimated quantitatively the impact of aircraft-related pollution in terms of the number of affected people for aircraft noise annoyance, odour annoyance and hypertension. In addition, an analysis of health registry data on cardiovascular and respiratory diseases and a short survey on annoyance and risk perception were carried out. The scope of a health impact assessment depends on the situation, available knowledge and data, concern in the population about the impact and the number of people concerned. It is important to pay attention to the perception of risks and concerns from all parties involved. Moreover, the results demonstrate that far more people outside the area for which standards apply were affected than inside.  相似文献   

15.
The San Francisco Bay estuary isused by over one million shorebirds during springmigration and is home to several hundred thousandduring the winter. Most shorebird use occurs in thesouthern reach of the estuary (South Bay). Thereduced water circulation and discharge fromindustrial sources in the South Bay are responsiblefor the highest levels of some trace elements in theestuary. Wintering shorebirds have been found to havestrong site fidelity to areas as small as a fewkilometers in the South Bay, which may increase theirexposure to contaminants near local point sources. Inaddition, different shorebird species foraging at thesame site have been shown to have differentcontaminant burdens. Thus, our objectives were totest whether contaminant burdens differed by species,or whether contaminant burdens differed in shorebirdscollected at adjacent sites. We examined thecontaminant profiles of two species of shorebirds,long-billed dowitchers (Limnodromus scolopaceus)and western sandpipers (Calidris mauri) thatforage together at two sites, Hayward and Newark,separated by 8 km in the South Bay. We usedmultivariate analysis of variance tests to compare thecomposition of 14 elemental analytes in their livertissues and estimated their molar ratios of Hg and Se. Composite samples were used for contaminant analysesbecause of the small body size of the shorebirds. Seven elemental analytes (Ag, Ba, Be, Cr, Ni, Pb, V)were below detection limits in a majority of thesamples so statistical analyses were precluded. Inthe measurable analytes (As, Cd, Cu, Hg, Mn, Se, Zn),we found no significant intra-site differences ofcontaminant profiles for the two species. We pooledthe samples to examine inter-site differences andfound significant differences in contaminant profilesbetween shorebirds at the neighboring sites (P = 0.03). Shorebirds at Newark had higher (P < 0.05) concentrations of As, Cd, and Se than those at Hayward. Dowitchers at Newark had concentrations of Hg and Se which were highly correlated (P < 0.003) in a mean molar ratio of 1:19, similar tothat reported in other birds. In the larger dowitcherspecies, we also examined exposure to 20organochlorine compounds. Organic analyses showedthat the dowitchers had been exposed to DDE, PCBs,dieldrin and trans-nonachlor, but with no significantdifferences in concentrations between Hayward andNewark (P > 0.05).  相似文献   

16.
土壤和底泥中砷、铬、锰测定的前处理技术   总被引:6,自引:0,他引:6  
试验了土壤和底泥中砷的前处理技术,其目的是能对土壤、底泥中砷、铬、锰在一次前处理中制备成试液,比色法分析。试验表明,用H2SO4-H3PO4-H2O2进行前处理是可行的。方法简单、挥发酸雾少,用标准参考物质检验证明,分解完全,数据准确,有粒较好一致性。  相似文献   

17.
Material Disposal Area G is the primary low-levelradioactive waste disposal site at Los Alamos NationalLaboratory, New Mexico, and is adjacent to Pueblo of SanIldefonso lands. Pueblo residents and Los Alamos scientists areconcerned about radiological doses resulting from uptake of AreaG radionuclides by mule deer (Odocoileus hemionus) andRocky Mountain elk (Cervus elaphus), then consumption ofdeer and elk meat by humans. Tissue samples were collected fromdeer and elk accidentally killed near Area G and were analyzedfor 3H, 90Sr, total U, 238Pu, 239, 240Pu,241Am, and 137Cs. These data were used to estimatehuman doses based on meat consumption of 23 kg y-1. Humandoses were also modeled using RESRAD, and dose rates to deer andelk were estimated with a screening model. Dose estimates tohumans from tissue consumption were 2.9 × 10-3 mSv y-1and 1.6 × 10-3 mSv y-1 from deer and elk, respectively,and RESRAD dose estimates were of the same order of magnitude. Estimated dose rates to deer and elk were 2.1 × 10-4 mGyd-1 and 4.7 × 10-4 mGy d-1, respectively. Allestimated doses were significantly less than established exposurelimits or guidelines.  相似文献   

18.
This paper presents the chemical speciation and retention behavior of chromium (Cr), nickel (Ni), and cadmium (Cd) prior to and after the electrokinetic remediation in glacial till soil. The speciation of the metals was predicted using the chemical speciation program MINEQL+. The simulations were performed for single-contaminant with only Cr(VI) or Ni, and multi-contaminants consisting of: (1) Cr(VI), Ni, and Cd; (2) Cr(III), Ni and Cd; (3) Cr(VI), Cr(III), Ni and Cd; (4) Cr(VI), Ni, and Cd with reducing agents; and (5) Cr(III), Ni, and Cd with oxidizing agent (Mn). The results showed that the speciation and distribution of cationic metals [Ni, Cd, and Cr(III)] in glacial till soil remain unaffected or slightly affected during electrokinetics. This is attributed to the high pH buffering capacity of the glacial till, leading the metals to precipitate in the soil prior to and after electrokinetics. This study showed that during electrokinetics, Cr(VI) existed as anionic complex and migrated towards the anode and the migration is maximum in case of a single-contaminant system. The study also showed that near the anode in the absence of any reducing and oxidizing agent, Cr(VI) mostly adsorbed, and some of Cr(VI) reduced to Cr(III) and migrated towards the cathode and finally precipitated due to high pH conditions. Ni and Cd remain adsorbed or precipitated due to the high pH conditions throughout the soil. Among the reducing agents, the sulfide had significant effect on the migration of metals compared to ferrous ions. While in the presence of oxidizing agent (Mn), no noticeable Cr(VI) was found in the soil sample indicating the reduction of Cr(VI) to Cr(III) and the predominance of reducing conditions due to the presence of naturally occurring iron in the glacial till soil. Overall, this study provides a reasonable explanation of the speciation and distribution of chromium, nickel and cadmium during the electrokinetic remediation of glacial till soil.  相似文献   

19.
We evaluated exposure of aquatic biota to lead (Pb), zinc (Zn), and cadmium (Cd) in streams draining a Pb-mining district in southeast Missouri. Samples of plant biomass (detritus, periphyton, and filamentous algae), invertebrates (snails, crayfish, and riffle benthos), and two taxa of fish were collected from seven sites closest to mining areas (mining sites), four sites further downstream from mining (downstream sites), and eight reference sites in fall 2001. Samples of plant biomass from mining sites had highest metal concentrations, with means 10- to 60-times greater than those for reference sites. Mean metal concentrations in over 90% of samples of plant biomass from mining sites were significantly greater than those from reference sites. Mean concentrations of Pb, Zn, and Cd in most invertebrate samples from mining sites, and mean Pb concentrations in most fish samples from mining sites, were also significantly greater than those from reference sites. Concentrations of all three metals were lower in samples from downstream sites, but several samples of plant biomass from downstream sites had metal concentrations significantly greater than those from reference sites. Analysis of supplemental samples collected in the fall of 2002, a year of above-average stream discharge, had lower Pb concentrations and higher Cd concentrations than samples collected in 2001, near the end of a multi-year drought. Concentrations of Pb measured in fish and invertebrates collected from mining sites during 2001 and 2002 were similar to those measured at nearby sites in the 1970s, during the early years of mining in the Viburnum Trend. Results of this study demonstrate that long-term Pb mining activity in southeast Missouri has resulted in significantly elevated concentrations of Pb, Cd, and Zn in biota of receiving streams, compared to biota of similar streams without direct influence of mining. Our results also demonstrate that metal exposure in the study area differed significantly among sample types, habitats, and years, and that these factors should be carefully considered in the design of biomonitoring studies.  相似文献   

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