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1.
煤矸石资源充分利用的新工艺 总被引:3,自引:0,他引:3
从煤矸石中提取氧化铝,并用残渣直接煅烧硅酸盐水泥熟料,同时作废气、废液循环,是煤矸石资源开发利用的新工艺。通过对工艺原理的研究,揭示了煤矸石-石灰石-纯碱烧结过程的反应历程及影响氧化铝提取率的因素,分析了残渣直接煅烧水泥熟料的机理和废气、废液循环利用的可能性,实现了资源的合理利用。 相似文献
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阐述了以挤出成型的方法综合利用煤矸石、粉煤灰和风化页岩生产烧结多孔砖的工艺过程.通过试验,对成型工艺、半成品的干燥过程,烧结阶段升温速度及烧成温度进行了详细的探讨,并确定了最佳的工艺参数 相似文献
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从煤矸石中提取氧化铝,废气和废液作封闭循环,并用残渣直接煅烧硅酸盐水泥熟料,是煤矸石高附加值,低污染的综合利用新工艺。本文通过对其工艺过程和产品性能的描述,确定了氧化铝提取率与其单位成本和残渣组成的关系,揭示了残渣中几种主要组成对煅烧工艺的影响,并对废气循环和溶液碳化分解的pH值问题进行了分析。 相似文献
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淮南选矸电解生产Al-Si-Ti合金的研究 总被引:2,自引:0,他引:2
对淮南煤矸石低温焙烧酸浸脱杂并电解生产AlSiTi合金进行了研究.结果表明,采用该工艺生产AlSiTi合金切实可行,关键在煤矸石中杂质的脱除,焙烧温度是影响脱杂的主要因素,在300—450℃之间能取得最佳脱杂效果,其杂质总量由10%左右降低到15%以下;脱杂煤矸石在温度为1000℃左右、阴阳极电流密度分别为07和10A/cm2电解条件下能被还原并共同沉积形成合金,所得合金化学组成符合国家标准相应牌号合金的要求. 相似文献
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煤矸石-粉煤灰-废石膏烧结陶粒 总被引:2,自引:0,他引:2
采用制粒烧结工艺成功地把煤矸石、粉煤灰及废石膏(或烟气脱硫污泥)制备成建筑用轻质陶粒,实现了对上述固体废物的资源化和稳定化。煤矸石等的配料比以及粉状原料的颗粒尺寸分布是在成球盘中制粒的主要影响因素。烧结过程中的影响因素较多,但烧结温度是影响产品质量的主要因素。煤矸石-粉煤灰-废石膏陶粒烧结过程发生在950—1250℃,最佳烧结温度为1200±50℃,制得的陶位坚硬如岩石,容重等级为900,筒压强度为9—15MPa,超过GB2838-81的筒压强度≥6.5MPa的规定。 相似文献
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赵勋卓 《辽宁城乡环境科技》2008,28(8)
煤矸石是我国排放量和堆存量最多的工业固体废弃物之一。介绍了在煤矸石多种利用途径中,以利用煤矸石制造烧结煤矸石砖的途径最为经济合理;提出了烧结煤矿石多孔砖生产过程污染的有效控制措施,并进行了综合效益分析。 相似文献
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Toxic effects of two agrochemicals on nifH gene in agricultural black soil were investigated using denaturing gradient gel electrophoresis (DGGE) and sequencing approaches in a microcosm experiment. Changes of soil nifH gene diversity and composition were examined following the application of acetochlor, methamidophos and their combination. Acetochlor reduced the nifH gene diversity (both in gene richness and diversity index values) and caused changes in the nifH gene composition. The effects of acetochlor on nifH gene were strengthened as the concentration of acetochlor increased. Cluster analysis of DGGE banding patterns showed that nifH gene composition which had been affected by low concentration of acetochlor (50 mg/kg) recovered firstly. Methamidophos reduced nifH gene richness that except at 4 weeks. The medium concentration of methamidophos (150 mg/kg) caused the most apparent changes in nifH gene diversity at the first week while the high concentration of methamidophos (250 mg/kg) produced prominent effects on nifH gene diversity in the following weeks. Cluster analysis showed that minimal changes of nifH gene composition were found at 1 week and maximal changes at 4 weeks. Toxic effects of acetochlor and methamidophos combination on nifH gene were also apparent. Different nifH genes (bands) responded differently to the impact of agrochemicals: four individual bands were eliminated by the application of the agrochemicals, five bands became predominant by the stimulation of the agrochemicals, and four bands showed strong resistance to the influence of the agrochemicals. Fifteen prominent bands were partially sequenced, yielding 15 different nifH sequences, which were used for phylogenetic reconstructions. All sequences were affiliated with the alpha- and beta-proteobacteria, showing higher similarity to eight different diazotrophic genera. 相似文献
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Arsenic uptake by arbuscular mycorrhizal maize (Zea mays L.) grown in an arsenic-contaminated soil with added phosphorus 总被引:1,自引:0,他引:1
XIA Yun-sheng CHEN Bao-dong CHRISTIE Peter SMITH F Andrew WANG You-shan LI Xiao-lin 《环境科学学报(英文版)》2007,19(10):1245-1251
The effects of arbuscular mycorrhizal (AM) fungus (Glomus mosseae) and phosphorus (P) addition (100 mg/kg soil) on arsenic (As) uptake by maize plants (Zea mays L.) from an As-contaminated soil were examined in a glasshouse experiment.Non-mycorrhizal and zero-P addition controls were included.Plant biomass and concentrations and uptake of As,P,and other nutrients,AM colonization,root lengths,and hyphal length densities were determined.The results indicated that addition of P significantly inhibited root colonization and development of extraradical mycelium.Root length and dry weight both increased markedly with mycorrhizal colonization under the zero-P treatments,but shoot and root biomass of AM plants was depressed by P application.AM fungal inoculation decreased shoot As concentrations when no P was added,and shoot and root As concentrations of AM plants increased 2.6 and 1.4 times with P addition,respectively.Shoot and root uptake of P,Mn,Cu,and Zn increased,but shoot Fe uptake decreased by 44.6%,with inoculation, when P was added.P addition reduced shoot P,Fe,Mn,Cu,and Zn uptake of AM plants,but increased root Fe and Mn uptake of the nonmycorrhizal ones.AM colonization therefore appeared to enhance plant tolerance to As in low P soil,and have some potential for the phytostabilization of As-contaminated soil,however,P application may introduce additional environmental risk by increasing soil As mobility. 相似文献
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Potential of plant polyphenol oxidases in the decolorization and removal of textile and non-textile dyes 总被引:2,自引:0,他引:2
In this study an effort has been made to use plant polyphenol oxidases; potato (Solanum tuberosum) and brinjal (Solanum melongena), for the treatment of various important dyes used in textile and other industries. The ammonium sulphate fractionated enzyme preparations were used to treat a number of dyes under various experimental conditions. Majority of the treated dyes were maximally decolorized at pH 3.0. Some of the dyes were quickly decolorized whereas others were marginally decolorized. The initial first hour was sufficient for the maximum decolorization of dyes. The rate of decolorization was quite slow on long treatment of dyes. Enhancement in the dye decolorization was noticed on increasing the concentration of enzymes. The complex mixtures of dyes were treated with both preparations of polyphenol oxidases in the buffers of varying pH values. Potato polyphenol oxidase was significantly more effective in decolorizing the dyes to higher extent as compared to the enzyme obtained from brinjal polyphenol oxidase. Decolorization of dyes and their mixtures, followed by the formation of an insoluble precipitate, which could be easily removed simply by centrifugation. 相似文献
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Removal of heavy metals from sewage sludge by low costing chemical method and recycling in agriculture 总被引:7,自引:0,他引:7
RemovalofheavymetalsfromsewagesludgebylowcostingchemicalmethodandrecyclinginagricultureWuQitang,NyirandegePascasie,MoCehuiF... 相似文献
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The influence of two pesticides including chlorimuron-ethyl and furadan and mercury (Hg) on urease activity in 4 soils (meadow burozem and phaeozem) was investigated. The soils were exposed to various concentrations of the two pesticides and Hg individually and simultaneously. Results showed that there was a close relationship between urease activity and organic matter content in soil. Chlorimuron-ethyl and furadan could both activate urease in the 4 soils. The maximum increment of urease activity by chlorimuronethyl was up to 14%-18%. There was almost an equal increase (up to 13%-21%) in the urease activity by furadan. On the contrary, Hg markedly inhibited soil urease activity. A logarithmic equation was used to describe the relationship (P〈0.05) between the concentration of Hg and the activity of soil urease in the 4 tested soils. Semi-effect dose (ED50) values by the stress of Hg based on the inhibition of soil urease in the 4 soils were 88, 5.5, 24 and 20 mg/kg, respectively, according to the calculation of the corresponding equations. The interactive effect of chlorimuron-ethyl or furadan with metal Hg on soil urease was mainly synergic at the highest tested concentrations. 相似文献
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A study was conducted to compare the diversity of 2-, 3-, and 4-chlorobenzoate degraders in two pristine soils and one contaminated sewage sludge. These samples contained strikingly different populations of mono-chlorobenzoate degraders. Although fewer cultures were isolated in the uncontaminated soils than contaminated one, the ability of microbial populations to mineralize chlorobenzoate was widespread. The 3- and 4-chlorobenzoate degraders were more diverse than the 2-chlorobenzoate degraders. One of the strains isolated from the sewage sludge was obtained. Based on its phenotype, chemotaxonomic properties and 16S rRNA gene, the organism S-7 was classified as Rhodococcus erythropolis. The strain can grow at temperature from 4 to 37℃. It can utilize several (halo)aromatic compounds. Moreover, strain S-7 can grow and use 3-chlorobenzoate as sole carbon source in a temperatures range of 10-30℃ with stoichiometric release of chloride ions. The psychrotolerant ability was significant for bioremediation in low temperature regions. Catechol and chlorocatechol 1,2-dioxygenase activities were present in cell free extracts of the strain, but no (chloro)catechol 2,3- dioxygenase activities was detected. Spectral conversion assays with extracts from R. erythropolis S-7 showed accumulation of a compound with a similar UV spectrum as chloro-cis,cis-muconate from 3-chlorobenzoate. On the basis of these results, we proposed that S-7 degraded 3-chlorobenzoate through the modified ortho-cleave pathway. 相似文献
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Organochlorine pesticides in soils under different land usage in the
Taihu Lake region, China 总被引:11,自引:0,他引:11
WANG Fang JIANG Xin BIAN Yong-rong YAO Fen-xi GAO Hong-jian YU Gui-fen Jean Charles MUNCH Reiner SCHROLL 《环境科学学报(英文版)》2007,19(5):584-590
A field study was conducted in the Taihu Lake region, China in 2004 to reveal the organochlorine pesticide concentrations in soils after the ban of these substances in the year 1983. Thirteen organochlorine pesticides (OCPs) were analyzed in soils from paddy field, tree land and fallow land. Total organochlorine pesticide residues were higher in agricultural soils than in uncultivated fallow land soils. Among all the pesticides, ΣDDX (DDD, DDE and DDT) had the highest concentration for all the soil samples, ranging from 3.10 ng/g to 166.55 ng/g with a mean value of 57.04 ng/g and followed by ΣHCH, ranging from 0.73 ng/g to 60.97 ng/g with a mean value of 24.06 ng/g. Dieldrin, endrin, HCB and α-endosulfan were also found in soils with less than 15 ng/g. Ratios of p,p'-(DDD DDE)/DDT in soils under three land usages were: paddy field > tree land > fallow land, indicating that land usage inlfuenced the degradation of DDT in soils. Ratios of p,p'-(DDD DDE)/DDT >1, showing aged residues of DDTs in soils of the Taihu Lake region. The results were discussed with data from a former study that showed very low actual concentrations of HCH and DDT in soils in the Taihu Lake region, but according to the chemical half-lives and their concentrations in soils in 1980s, the concentration of DDT in soils seemed to be underestimated. In any case our data show that the ban on the use of HCH and DDT resulted in a tremendous reduction of these pesticide residues in soils, but there are still high amounts of pesticide residues in soils, which need more remediation processes. 相似文献
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The contribution of aliphatic-rich plant biopolymer to sorption of hydrophobic organic compounds is significantly important because of their preservation and accumulation in the soil environment,but sorption mechanism is still not fully understood.In this study, sorption of 1-naphthol by plant cuticular fractions was examined to better understand the contributions of respective fraction.Toward this end,cuticular materials were isolated from the fruits of tomato by chemical method.The tomato cuticle sheet consisted of waxes (6.5 wt%),cuticular monomer (69.5 wt%),and polysaccharide (24.0 wt%).Isotherms of l-naphthol to the cuticular fractions were nonlinear (N value (0.82-0.90)) at the whole tested concentration ranges.The KodKow ratios for bulk cuticle (TC1),dewaxed cuticle (TC2),cutin (TC4),and desugared cuticle (TC5) were larger than unity,suggested that tomato bulk cuticle and cutin are much powerful solption medium.Sorption capability of cutin (TC4) was 2.4 times higher than the nonsaponifiable fraction (TC3).The 1-naphthol interactions with tomato cuticular materials were governed by both hydrophobic-type interactions and polar (H-bonding) interactions. Removal of the wax and polysaccharide materials from the bulk tomato cuticle caused a significant increase in the sorption ability of the cuticular material.There was a linear negative trend between K_(oc) values and the amount of polysaccharides or fraction's polarities ((N O)/C);while a linear positive relationship between K_(oc) values and the content of cutin monomer (linear R~2=0.993) was observed for present in the cuticular fractions.Predominant sorbent of the hydrophobic organic compounds (HOCs) in the plant cuticular fraction was the cutin monomer,contributing to 91.7% of the total sorption of tomato bulk cuticle. 相似文献
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Alisa Wangsongsak Suwimol Utarnpongs Maleeya Kruatrachue MathurosePonglikitmongko Prayad Pokethitiyook Thitinun Sumranwanich 《环境科学学报(英文版)》2007,19(11):1341-1348
Common silver barb,Puntius gonionotus,exposed to the nominal concentration of 0.06 mg/L Cd for 60 d,were assessed for histopathological alterations(gills,liver and kidney),metal accumulation,and metallothionein(MT)mRNA expression.Fish exhibited pathological symptoms such as hypertrophy and hyperplasia of primary and secondary gill lamellae,vacuolization in hepatocytes,and prominent tubular and glomerular damage in the kidney.In addition,kidney accumulated the highest content of cadmium,more than gills and liver.Expression of MT mRNA was increased in both liver and kidney of treated fish.Hepatic MT levels remained high after fish were removed to Cd-free water.In contrast,MT expression in kidney was peaked after 28 d of treatment and drastically dropped when fish were removed to Cd-free water.The high concentrations of Cd in hepatic tissues indicated an accumulation site or permanent damage on this tissue. 相似文献
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SONG Yong-hui Dietfried DONNERT Ute BERG Peter G. WEIDLER Rolf NUEESCH 《环境科学学报(英文版)》2007,19(5):591-595
Seed induces and promotes the crystallization of calcium phosphate, and acts as carrier of the recovered phosphorus (P). In order to select suitable seed for P recovery from wastewater, three seeds including Apatite (AP), Juraperle (JP) and phosphate-modified Juraperle (M-JP) were tested and compared. Batch and fixed-bed column experiments of seeded crystallization of calcium phosphate were undertaken by using synthetic wastewater with 10 mg/L P phosphate. It shows that AP has bad enduring property in the crystallization process, while JP has better performance for multiple uses, and M-JP is a hopeful seed for P recovery by crystallization of calcium phosphate. 相似文献