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化学需氧量(CODCr)与总有机碳(TOC)指标均可用来表征废水的有机物污染程度.不过,以CODCr表征有机物污染程度一般只能反映水中部分有机物的量,而TOC能更全面地反映废水中有机物的含量.以丙烯酸生产外排废水为研究对象,分析结果表明:在一定范围内,废水中CODCr与TOC满足关系式y=1.147 4x+74.75(R2=0.955 26),回收率范围98%~115%,TOC测定结果的精密度高、可靠、准确,在一定条件下,可使用TOC来间接换算CODCr. 相似文献
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本文利用2-氨基吡啶与4-二乙胺基水杨醛反应合成了5-二乙胺基-2-(吡啶-2’-亚氨甲基)苯酚(探针L),对其结构进行了表征。在DMSO/Tris(6:4, v/v, pH =7.4)溶液中,探针L高选择性荧光“关-开”识别Zn2+,在365 nm紫外灯照射下,由无荧光变成蓝色荧光。实验表明,探针L与Zn2+的结合比为1:1,结合常数为2.6×103 L. mol-1,检测限为 9.39×10-7mol/L,pH适用范围为7-11,并可检测水样中的Zn2+。 相似文献
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本文研究了环戊基全取代六元瓜环(CyP6Q[6])与2-(β-吡啶)-1H-咪唑 [4,5-f][1,10] 菲咯啉盐酸盐 (即Ar-IPHS) 的主客体相互作用,并利用CyP6Q[6]可使Ar-IPHS产生强烈的荧光的性质制备了Ar-IPHS@ CyP6Q[6]荧光探针用以识别氨基酸。实验结果发现,探针可高效识别甘氨酸,赖氨酸,甲硫氨酸,检测限分别为2.27x10-6mol/L、1.359x10-5mol/L、1.690x10-5mol/L。 相似文献
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在离子液体BMImPF6中, 用不同的钯催化剂和Lewis酸三氟甲磺酸铜Cu(OTf)2共催化苯乙烯二聚反应, 发现用Pd(OAc)2/Cu(OTf)2作催化剂, Pd/Cu物质的量之比为1~4时, 可高产率高选择性地获得苯乙烯二聚产物1,3-二苯基-1-丁烯. BMImPF6对催化剂有较好的溶解性, 可固定催化剂体系, 使催化剂有效地与产品分离. 同时, α-甲基苯乙烯的二聚反应表明, 室温下不发生反应, 提高温度有利于反应进行. 相似文献
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利用3,5-二(3-吡啶)-4-氨基-1,2,4-三唑(L)配体与Co(Ⅱ)/Cu(Ⅱ)盐室温下反应得到了一维的配位聚合物{[CoL(H2O)4]SO4·H2O}n(1)和单核配合物[Cu(hfac)2L2](2,hfac=hexafluoroacetylacetonate)。通过红外、元素分析及X射线单晶衍射等检测手段对所合成的配合物进行了表征。结构研究表明,配合物1中,配体L呈顺式构型,采取双齿配位方式桥联Co(Ⅱ)离子形成一维正弦链状结构,一维链通过多种氢键相互作用连接进一步形成三维网状结构;溶剂水分子和硫酸根阴离子通过氢键连接在框架上。配合物2中,配体L则采取单齿配位方式,与Cu(Ⅱ)离子形成离散型的单核结构,通过多重氢键作用进而连接成三维网状结构。 相似文献
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取代吡唑-5-酰基杂环衍生物的合成、结构与生物活性 总被引:8,自引:0,他引:8
为了寻求新的含吡唑双杂环先导化合物. 用4-取代-1-甲基-3-乙基-5-吡唑甲酰氯与2-噻唑烷酮、2-噻唑硫酮、2-噁唑烷酮等含氮杂环反应得到了12个含吡唑环的双杂环化合物. 化合物结构用IR, 1H NMR, MS和元素分析进行了表征. 并用X射线单晶衍射法测定了化合物3-(1-甲基-3-乙基-4-硝基-5-吡唑甲酰基)-噁唑烷-2-酮(3k)的晶体结构. 晶体为单斜晶系, P21/n (#14)空间群, a=1.52175(3) nm, b=0.52970(1) nm, c=1.58185(3) nm, β=104.893(4), V=1.2323(4) nm3, Z=4, Dc=1.45 g/cm3, F(000)=560.00, R1=0.064, wR2=0.193. 初步生物活性实验结果表明, 在25 mg/L浓度下, 3-(1-甲基-3-乙基-4-硝基-5-吡唑甲酰基)-噻唑烷-2-酮(3c), 3-(1-甲基-3-乙基-4-硝基-5-吡唑甲酰基)-噻唑烷-2-硫酮(3g)对水稻稻瘟病菌(Pyricularia oryzae)的抑制活性达到40%. 在500 mg/L浓度下, 3-(1-甲基-3-乙基-4-溴-5-吡唑甲酰基)-噻唑烷-2-酮(3d), 3-(1-甲基-3-乙基-4-溴-5-吡唑甲酰基)-噁唑烷-2-酮(3l)对稻黑尾叶蝉(Nephotettix cinc-ticeps)的抑制活性达到53.37%. 相似文献
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Stephan Wasielewski Eduard Rott Ralf Minke Heidrun Steinmetz 《Molecules (Basel, Switzerland)》2021,26(1)
Sludge water (SW) arising from the dewatering of anaerobic digested sludge causes high back loads of ammonium, leading to high stress (inhibition of the activity of microorganisms by an oversupply of nitrogen compounds (substrate inhibition)) for wastewater treatment plants (WWTP). On the other hand, ammonium is a valuable resource to substitute ammonia from the energy intensive Haber-Bosch process for fertilizer production. Within this work, it was investigated to what extent and under which conditions Carpathian clinoptilolite powder (CCP 20) can be used to remove ammonium from SW and to recover it. Two different SW, originating from municipal WWTPs were investigated (SW1: c0 = 967 mg/L NH4-N, municipal wastewater; SW2: c0 = 718–927 mg/L NH4-N, large industrial wastewater share). The highest loading was achieved at 307 K with 16.1 mg/g (SW1) and 15.3 mg/g (SW2) at 295 K. Kinetic studies with different specific dosages (0.05 gCLI/mgNH4-N), temperatures (283–307 K) and pre-loaded CCP 20 (0–11.4 mg/g) were conducted. At a higher temperature a higher load was achieved. Already after 30 min contact time, regardless of the sludge water, a high load up to 7.15 mg/g at 307 K was reached, achieving equilibrium after 120 min. Pre-loaded sorbent could be further loaded with ammonium when it was recontacted with the SW. 相似文献
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Zheng GH Li MN Wang L Chen ZY Qian YF Zhou Q 《Applied biochemistry and biotechnology》2008,144(2):101-109
The activated sludge process generates a large amount of excess sludge as a byproduct, which is one of the most serious challenges
in biological wastewater treatment. In the present study, the feasibility of 2,4,6-trichlorophenol (TCP) and malonic acid
(MA) as metabolic uncouplers to reduce sludge generation in the sequence batch reactor (SBR) for treating organic wastewater
for a long period was studied. The results showed that 2 mg/L TCP could reduce sludge generation by about 47%, while chemical
oxygen demand (COD) removal efficiency and sludge settlability were not obviously influenced. Although 10 mg/L MA could also
reduce excess sludge production by about 30% while slightly affecting COD removal, it seriously deteriorated sludge settlability.
Accordingly, TCP is a better uncoupler for sludge reduction for a longer period in the SBR for treating organic wastewater,
and MA can only be used as a short-term or transitional uncoupler. Microscopic and 16S ribosomal deoxyribonucleic acid analyses
showed that the microbial population of sludge varied when uncouplers were fed to the activated sludge system. Occurrence
of large amounts of filament and the disappearance of protozoa may be the main reason for the aggravation of sludge settlability
under uncoupled metabolic conditions caused by MA. 相似文献
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Lilian Danielle de Moura Torquato Sônia de Almeida José Eduardo de Oliveira Marisa Spirandeli Crespi Sandra Imaculada Maintinguer 《Journal of Thermal Analysis and Calorimetry》2017,127(2):1267-1275
A wide variety of organic residues may be used as energy source such as anaerobic sludge from wastewater treatment systems. However, due to inherent differences in composition, the proper characterization of these biomasses is essential to support their reuse through any conversion process. The aim of this study was the employment of thermal analysis techniques (TG/DTG and DTA) to perform the characterization of anaerobic sludges from different wastewater treatment plants (industrial and municipal), which were further applied for biological production of H2. The different profiles observed through thermal characterization support the application of these residues as inocula, confirming their potential for H2 production, while demonstrating the main causes for the different yields obtained (mol H2 mol?1 sucrose): 0.9 from sludge of brewery industry and 2.0 from sludge of municipal wastewater treatment plant, corresponding to the overall yields of 10.8 and 25%, respectively. These results confirm the versatility of thermal analysis techniques for biomass characterization, focused on its application for power generation. It is urgent to adopt more sustainable and cost-effective solutions for their management, considering a large amount of residues daily generated in both treatment processes addressed; therefore, biohydrogen production by anaerobic digestion may be a promising alternative for the reuse of both residues as it promotes their transformation from costly and potentially polluting waste into clean and renewable energy sources. The development of this anaerobic process is even more attractive in countries as Brazil, where the weather conditions are naturally favorable. 相似文献
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《中国化学快报》2023,34(2):107439
The horizontal flow anaerobic digester indicated that high ammonia (2923 mg/L) and SO42? (3653 mg/L) would influence the performance of methane production with food waste as substrates. Therefore, bottle anaerobic digestion reactors were carried out to investigate the effect of ammonia/sulfate concentrations on the methane production. Experimental results manifested that the anaerobic digesters with an ammonia concentration of 3500 mg/L or sulfate of 1600 mg/L showed the best performance of methane production, with an average methane yield of 0.32 and 0.33 L (g VS)?1 d?1, respectively. Specifically, a higher ammonia (6500 mg/L) or sulfate (1600-3500 mg/L) level hindered the bioconversion of C from liquid to gas phase (2.68% or 1.73% CH4-Gas, respectively), while insignificantly for the hydrolyzation of C and N from solid to liquid phase. Similar to sulfate, high ammonia nitrogen seriously inhibited the methanation process, leading to a significant carbon accumulation in the anaerobic reactor, especially for propionic acid. The predominant archaea Methanosarcina at genus level indicated that aceticlastic methanogenesis was the major methanogenic pathway. Meanwhile, high ammonia level suppressed the activity of Methanosarcina, while modest sulfate improved H2-consuming methanogens activity. A large fraction of unclassified bacteria within the Firmicutes (43.78%-63.17%) and Bacteroidetes (24.20%-33.30%) phylum played an important role in substrates hydrolysis. 相似文献
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Anaerobic treatment of low-strength brewery wastewater in expanded granular sludge bed reactor 总被引:2,自引:0,他引:2
Anaerobic treatment of low-strength brewery wastewater, with influent total chemical oxygen demand (COD) (CODin) concentrations ranging from 550 to 825 mg/L, was investigated in a pilot-scale 225.5-L expanded granular sludge bed (EGSB) reactor. In an experiment in which the temperature was lowered stepwise from 30 to 12 degrees C, the COD removal efficiency decreased from 73 to 35%, at organic loading rates (OLR) of 11-16.5 g COD/L/d. The applied hydraulic retention time (HRT) and liquid upflow velocity (Vup) were 1.2 h and 5.8 m/h, respectively. Under these conditions, the acidified fraction of the CODin varied from 45 to 90%. In addition to the expected drop in reactor performance, problems with sludge retention were also observed. In a subsequent experiment set at 20 degrees C, COD removal efficiencies exceeding 80% were obtained at an OLR up to 12.6 g COD/L/d, with CODin between 630 and 715 mg/L. The values of HRT and Vup applied were 2.1-1.2 h, and 4.4-7.2 m/h, respectively. The acidified fraction of the CODin was above 90%, but sludge washout was not significant. These results indicate that the EGSB potentials can be further explored for the anaerobic treatment of low-strength brewery wastewater, even at lower temperatures. 相似文献
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Chairattanamanokorn P Tapananont S Detjaroen S Sangkhatim J Anurakpongsatorn P Sirirote P 《Applied biochemistry and biotechnology》2012,166(2):389-401
Dark anaerobic fermentation is an interesting alternative method for producing biohydrogen (H2) as a renewable fuel because of its low cost and various usable organic substrates. Pulping sludge from wastewater treatment
containing plentiful cellulosic substrate could be feasibly utilized for H2 production by dark fermentation. The objective of this study was to investigate the optimal proportion of pulping sludge
to paper waste, the optimal initial pH, and the optimal ratio of carbon and nitrogen (C/N) for H2 production by anaerobic seed sludge pretreated with heat. The pulping sludge was pretreated with NaOH solution at high temperature
and further hydrolyzed with crude cellulase. Pretreatment of the pulping sludge with 3% NaOH solution under autoclave at 121 °C
for 2 h, hydrolysis with 5 FPU crude cellulase at 50 °C, and pH 4.8 for 24 h provided the highest reducing sugar production
yield (229.68 ± 2.09 mg/gTVS). An initial pH of 6 and a C/N ratio of 40 were optimal conditions for H2 production. Moreover, the supplement of paper waste in the pulping sludge enhanced the cumulative H2 production yield. The continuous hydrogen production was further conducted in a glass reactor with nylon pieces as supporting
media and the maximum hydrogen production yield was 151.70 ml/gTVS. 相似文献
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Textile and dye industries are main sources of dye bearing effluent. In present studies the anaerobic biological degradation of Acid Red 3BN dye water (AR3BNDW) and mixed dye water (MDW) for reduction of color and COD were studied in sequential batch reactor (SBR). The sludge as sources of microorganism was arranged from maize processing bio methanation wastewater treatment plant, which was acclimatized for treatment of AR3BNDW and MDW. After the acclimatization, dyes degradation were studied in SBR At optimum operation condition of hydraulics retention time (HRT) = 2.5 d, and treatment time (tR) = 16 h, AR3BNDW have gone maximum 87% color reduction of 500 mg/L dye, and 82.8% COD reduction of 380 mg/L COD. At same operating condition, 84.5% color reduction of 500 mg/L dye, and 79.42% COD reduction of 413 mg/L COD achieved for MDW. The second order Grau model was fitted well for COD and dye reductions. The kinetics parameter were evaluated for both the dye water. 相似文献
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Combined biologic (anaerobic-aerobic) and chemical treatment of starch industry wastewater 总被引:2,自引:0,他引:2
Sklyar V Epov A Gladchenko M Danilovich D Kalyuzhnyi S 《Applied biochemistry and biotechnology》2003,109(1-3):253-262
A combined biologic and chemical treatment of high-strength (total chemical oxygen demand [CODtot] up to 20 g/L), strong nitrogenous (total N up to 1 g/L), and phosphoric (total P up to 0.4 g/L) starch industry wastewater was investigated at laboratory-scale level. As a principal step for COD elimination, upflow anaerobic sludge bed reactor performance was investigated at 30 degrees C. Under hydraulic retention times (HRTs) of about 1 d, when the organic loading rates were higher than 15 g of COD/(L.d), the CODtot removal varied between 77 and 93%, giving effluents with a COD/N ratio of 4-5:1, approaching the requirements of subsequent denitrification. The activated sludge reactor operating in aerobic-anoxic regime (HRT of about 4 d, duration of aerobic and anoxic phases of 30 min each) was able to remove up to 90% of total nitrogen and up to 64% of COD tot from the anaerobic effluents under 17-20 degrees C. The coagulation experiments with Fe(III) showed that 1.4 mg of resting hardly biodegradable COD and 0.5 mg of phosphate (as P) could be removed from the aerobic effluents by each milligram of iron added. 相似文献
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《Arabian Journal of Chemistry》2022,15(3):103664
Electroplating is a common process of converting zinc ion in electrolyte as a micro level zinc layer on electroplating pieces. After electroplating, the remaining electrolyte on the surface of the pieces is washed with water, and accordingly, Zn-containing electroplating wastewater is generated. Hazardous Zn-containing wastewater is generated during the washing of electroplating pieces and plating tank. Herein, Zn was enriched from wastewater by commercial flocculant and then recycled as highly purified zinc phosphate via coupled acid extraction and hydrothermal treatment. Firstly, 98.4% Zn was recovered as sludge from wastewater by adding 0.2 g/L of flocculant. Then, the sludge was dissolved into an acid solution to produce a leachate with 31.2/10.8/19.3 g/L of Fe/Al/Zn and then hydrothermally treated to remove Fe/Al. The Fe removal rate was only 54.2% without phosphate and glucose but was increased to 98.6% after the addition of 0.5 g of glucose with Al/Zn loss < 2%. However, when 0.5 g of glucose and 15 g/L of phosphate were used, 99.8% Fe and 96.6% Al were synchronously removed as giniite with Zn loss < 2%. After Fe/Al separation, the remaining Zn was finally recycled as Zn phosphate particles with 98.1 wt% Zn3(PO4)2·2H2O. The added phosphate predominated the synergy removal of Fe/Al and especially lowered the Gibbs value of Al hydrolysis from 39.7 kJ/mol of boehmite to ?5.96 kJ/mol of giniite, thereby reducing start-up temperature and reaction time. The proposed method showed practical application in the enrichment and recycling of valuable metals from wastewater. 相似文献
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A wide range of products are produced in the chemical producing industry such as textile dyes, chemicals, printing dyes and chemicals, paper chemicals, electrostatic powder dyes, and optical brighteners. The aim of this study is to investigate the treatability of chemical oxygen demand (COD), aromaticity, and color in the wastewater of this sector, where highly complex chemicals are used. Most of the studies in the literature are related to the treatment of synthetically prepared dyed wastewater. This study is important as it is carried out with real wastewater and gives results of many treatment methods. In the study, COD, UV-vis absorbance, and color values were attempted to be removed from the wastewater of a chemical producing industry that was pretreated by coagulation-flocculation. The COD value of the pretreated wastewater discharged to the central treatment system was restricted as 1000 mg/L. Pretreated wastewater characterization is as follows: COD: 2117 mg/L, UV-vis absorbance values at; 254 nm: 9.91, 280 nm: 8.65, 341 nm: 12.77, 436 nm: 5.01, 525 nm: 2.24, and 620 nm: 1.59. In the study, adsorption, ozonation, and advanced oxidation processes (Fenton and persulfate oxidation) were used to remove COD and UV-vis absorbance values (aromaticity, organics, and color). The method by which the best removal efficiency was obtained for all parameters was the adsorption process using powdered activated carbon (PAC). The equilibrium PAC dose was found as 6 g/L. At this adsorbent dose, the removal efficiencies of UV-vis absorbance values were all around 99% and the efficiency of COD removal was 77%. The Langmuir isotherm constants were found to be qmax= 30.4 mg/g and KL = 487.9 (L/mg). The COD concentration at this adsorbent dose was 486 mg/L and wastewater was suitable for discharge to the central wastewater treatment plant in that region. 相似文献