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451.
翅碱蓬(Suaeda heteroptera)根际沉积物中四种常见重金属(Cu、Zn、Pb和cd)的总量次序为Zn〉Pb〉Cu〉Cd,且随潮滩变化明显。重金属总量在根际沉积物中高于非根际沉积物,尤以中潮滩差异最显著。对根际沉积物重金属5种化学形态(交换态、碳酸盐结合态、铁锰氧化物结合态、有机态和残渣态)分析发现,Cu、Pb均以残渣态为主,其次为碳酸盐结合态,可交换态为最低;Zn以可交换态为主,其次分别为碳酸盐结合态和残渣态,最低为铁锰氧化物结合态和有机态。基于生物可利用性,上述5种形态可以分为活性态(包括交换态、碳酸盐结合态、铁锰氧化物结合态、有机态)和残渣态两大类。研究发现,根际沉积物化学形态转化趋势与元素性质有关,Cu、Pb由活性态向残渣态转化,生物可利用性降低;Zn由残渣态向活性态转化,生物可利用性升高。  相似文献   
452.
线路板工业废水处理工程实践   总被引:2,自引:0,他引:2  
阐述了运用分质、分类进行物化和生化的方法处理线路板工业废水的工程实例。运行结果表明,该工艺切实可行,使种类复杂的线路板工业废水处理达到了《污水综合排放标准》(GB8978-1996)一级排放标准。  相似文献   
453.
餐饮废水的化学处理方法研究   总被引:2,自引:0,他引:2  
以聚硅酸铝为混凝剂,用化学法絮凝处理餐饮废水。考查了酸度、混凝剂加入量、搅拌速度、搅拌时间、沉降时间对CODCr去除率的影响。结果表明酸度在pH9~11范围内,每100mL污水中聚硅酸铝加入量为02mL,搅拌速度为45r/min,搅拌15s,沉降15min后,测上清液的化学耗氧量,CODCr去除率可达88%左右。该方法效果好、工艺简单、易于操作管理,有实际应用价值。  相似文献   
454.
Ongoing, rapid urban growth accompanied by habitat fragmentation and loss challenges biodiversity conservation and leads to decreases in ecosystem services. Application of the concept of ecological networks in the preservation and restoration of connections among isolated patches of natural areas is a powerful conservation strategy. However, previous approaches often failed to objectively consider the impacts of complex 3-D city environments on ecological niches. We used airborne lidar-derived information on the 3-D structure of the built environment and vegetation and detailed land use and cover data to characterize habitat quality, niche diversity, and human disturbance and to predict habitat connectivity among 38 identified habitat core areas (HCAs) in Nanjing, China. We used circuit theory and Linkage Mapper to create a landscape resistance layer, simulate habitat connectivity, and identify and prioritize important corridors. We mapped 64 links by using current flow centrality to evaluate each HCA's contribution and the links that facilitate intact connectivity. Values were highest for HCA links located in the west, south, and northeast of the study area, where natural forests with complex 3-D structures predominate. Two smaller HCA areas had high centrality scores relative to their extents, which means they could act as important stepping stones in connectivity planning. The mapped pinch-point regions had narrow and fragile links among the HCAs, suggesting they require special protection. The barriers with the highest impact scores were mainly located at the HCA connections to Purple Mountain and, based on these high scores, are more likely to indicate important locations that can be restored to improve potential connections. Our novel framework allowed us to sufficiently convey spatially explicit information to identify targets for habitat restoration and potential pathways for species movement and dispersal. Such information is critical for assessing existing or potential habitats and corridors and developing strategic plans to balance habitat conservation and other land uses based on scientifically informed connectivity planning and implementation.  相似文献   
455.

Vibrio bacteria live in both marine and freshwater habitats and are associated with aquatic animals. Vibrio vulnificus is a pathogenic bacterium that infects people and livestock. It is usually found in offshore waters or within fish and shellfish. This study presents a comparative proteomic analysis of the outer membrane protein (OMP) changes in V. vulnificus proteins after stimulation with sewage from sewage drains. Using two-dimensional electrophoresis followed by MALDI-TOF MS/MS, 32 protein spots with significant differences in abundance were identified and characterized. These identified proteins were found to be involved in various functional categories, including catalysis, transport, membrane proteins progresses, receptor activity, energy metabolism, cytokine activity, and protein metabolism. The mRNA expression levels of 12 differential proteins were further assessed by qRT-PCR. Seven genes including carboxypeptidase, hemoglobin receptor, succinate dehydrogenase iron-sulfur subunit, ATP synthase subunit alpha, thioredoxin, succinyl-CoA synthetase subunit, and alanine dehydrogenase were downregulated upon stimulation, whereas the protein expression levels HupA receptor, type I secretion outer membrane protein, glutamine synthetase, superoxide dismutase, OmpU, and VuuA were upregulated. 1H NMR spectra showed 18 dysregulated metabolites from V. vulnificus after the sewage stimulation and the pathogenicity was enhanced after that.

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456.
以浙江省为例,深入分析特种纸行业发展现状及特点、水污染物排放控制水平和企业在执行国家现有污染物排放标准过程中存在的问题与原因。针对特种纸的特殊性,从完善造纸行业标准体系的角度,提出制定特种纸行业污染物排放标准,确定一厂一策的标准执行体系的建议;从提升产业污染控制水平及产业转型升级角度,提出按规模、分区域、分纸品确定转型重点,研究制定最佳可行技术导则,加快污染治理设施的提升改造,加强企业技改力度及提高清洁生产水平等对策与建议,以促进特种纸行业的可持续发展。  相似文献   
457.
以绍兴县综合性印染废水为处理对象,采用混凝一水解酸化一好氧工艺,并且在好氧单元中投加微生物菌剂进行中试研究,探讨了该工艺对印染废水的处理效能。结果表明,投加菌剂后,该系统出水大大改善。投加茵剂前,出水CODl91mg/L,投加菌剂后,出水111mg/L。当该系统高效茵群已形成后,不投加茵剂20天内,该系统仍然可以保持出水CODl21mg/L。当该系统MLSS大量降低后,该系统出水仍然可达120mg/L,此现象说明该系统耐受冲击能力强,且为污泥的减量化研究可能指明了一个新方向。  相似文献   
458.
The sedimentation of metals can preserve the historical record of contaminant input from local and regional sources and provide information on the historical changes in regional water and sediment quality. We report the 210Pb activities and the heavy metal (Cd, Cr, Cu, Mn, Pb and Zn) depth profiles from sediment cores retrieved in 2010. The mean sedimentation rates of 0.85-1.5 cm/yr are determined by 210Pb dating. The sediments in the tidal flat have recorded heavy metal deposition and thus allow the establishment of a connection between the temporal evolution of the heavy metal pollution and the historical changes in the economic development of Lianyungang. The enrichment factors (EF) are calculated to estimate the level of contamination stored in these sediments. The results show that in the studied sites, Cr and Cu display low EF values and are mainly from lithogenic origin. For the other studied trace metals, a great variability in the sedimentary record is observed. Significant anthropogenic enrichment over the last 50 years is revealed at the tidal flat that receives fluvial inputs. Zinc is the element with the highest EF values, followed by the order of Pb > Cd > Mn > Cu and Cr. The temporal variations of the heavy metals peak during the late 1980s to the early 2000s and show a decreasing trend afterward. The pollution intensity of the tidal flat is determined by using EF and the geo-accumulation index (Igeo), which show that, based on the Igeo scale, the tidal flat of Haizhou Bay is unpolluted to moderately polluted.  相似文献   
459.
胡文  康媞  丁剑秋 《环境工程》2013,(Z1):139-140,146
利用电石渣对煤矿酸性废水进行处理,达到以废治废的目的。为此对该技术进行研究。在反应停留时间为29 h,pH为6.93时,出水总铁为4.00 mg/L、亚铁为2.01 mg/L、总锰为0.90 mg/L,去除率分别为:总铁:99.04%、亚铁:99.44%、总锰:86.86%。出水指标达GB 20426—2006《煤炭工业污染物排放标准》的要求。  相似文献   
460.
Organic phosphorus(nonreactive P,NRP)is a major component of P in sediments,but information about its chemical forms and dynamic transformation is limited.The chemical forms and dynamic behaviors of NRP in a sediment profile from Lake Taihu,a freshwater and eutrophic lake in China,were investigated.Five forms of NRP in the sediments were extracted based on a chemical fractionation technique,including easily labile NRP(NaHCO3-NRP),reactive metal oxide-bound NRP(HCl-NRP),humic acid-associated NRP(NaOH-NRPHA),fulvic acid-associated NRP(NaOH-NRPFA)and residual NRP(Res-TP).There were notable transformations with increasing sediment depth from the labile NaHCO3-NRP and NaOH-NRP pools to the recalcitrant HCl-NRP and Res-TP pools,which caused the NRP to become increasingly recalcitrant as the early diagenetic processes proceeded.Further analyses showed that the relative changes in contents of organic matter and reactive Fe oxides in the sediment profile triggered a competition for binding NRP fractions and led to the transformation of NRP.The results highlighted the importance of abiotic processes in regulating the diagenesis of organic P and its stability in sediments.  相似文献   
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