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锌湿法冶炼废水中锌,镁的连续测定 总被引:2,自引:0,他引:2
本文介绍冶炼废水中锌和镁进行了测定方法的实验研究。实验证明:在pH5.5和pH10的两种缓冲介质中,以2.0g/LXO指示剂0.15mg/L和5g/LEBT指示剂1.5mg/L为指示剂,在掩蔽Fe^3+和Cd^2+、Ca^2+后,进行EDTA络合滴定,结果准确、可靠,且方法具有简单迅速的优点。 相似文献
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味精浓度水稀释液厌氧消化—SBR工艺处理 总被引:5,自引:0,他引:5
采用UBF-SBR工艺处理味精浓度水稀释液,UBF段的进水CODcr18900mg/L,NH3-N1500mg/L,有机容积负荷率9.45kg(COD)/m^3.d时,CODcr平均去除率为84.5%,SBR段的进水CODcr2950mg/L,NH3-N1678mg/L,曝气65h,DO为4~4.5mg/L,停曝气时DO在0.3mg/L以下,CODcr和NH3-N的平均去除率分别为92%和99.4 相似文献
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本研究采用SBR技术处理毒性大、可生化性差的焦化污水。当污水CODor、酚和氰浓度分别为1400-2000mg/L,230-380mg/L和1.90-3.76mg/L时,经处理后,出水CODor〈250mg/L(混凝后,CODor〈200mg/L),酚和氰均远低0.5mg/L,CODor酚和氰的去除率分别为91%、99.8%和95%,大大高于连续流一化处理焦化污水的效果。试验结果表明,SBR系统操 相似文献
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热带海洋环境中BHC和DDT的行为特征研究:Ⅰ.中国珠江口区旱季BHC… 总被引:11,自引:3,他引:11
本文物1994年11月用气相色谱法研究了旱季珠江口区环境中BHC和DDT的含量与分布。结果表明,表层海水BHC含量为0.087μg/L,DDT为0.080μg/L;底层海水BHC为0.117μg/L,DDT为0.506μg/L。沉积物BHC为11.15×10^-9(干),DDT为33.46×10^-9(干)。海水中的盐度、DO、COD与其BHC、DDT含量之相关性没有规律,沉积物中微生物的含量与B 相似文献
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研究了在25℃条件下重铬酸钾对方形网纹涤Ceriodaphniaquadrangula(O,F.Muler)存活、生殖和生长的影响。急性试验求得铬铬酸钾对该僵的24h和48hBc50值分别为1.0179mg/L和0.4127mg/L;其可信限分别为0.4698一1.7180mg/L和0.1980一0.6988mg/L。慢性试验以存活、生殖和生长为毒性指标,未觉察反应浓度(NOEC)为0.0625mg/L,最低觉察反应浓度(LOEO)为0.1250mg/L,其应用系数在0.15一0.30之间。流水试验(NOEC)为0.03125mg/L,(LOEC)为0.0625mg/L,其应用系数在0.08一0.15之间。结果还表明生长是最敏感的指标。 相似文献
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以水稻为材料,研究了不同浓度的模拟N、P污水对幼苗过氧化物酶(POD,EC1.11.1.7)和超氧化物歧化酶(SOoD,EC1.15.1.1)及其同工酶等的影响,结果表明:在总氮浓度(Nr)为0─90mg/L和总磷浓度(P_T)为0─9mg/L范围内,POD与N、P浓度呈正相关,N_T超过90mg/L和P_T超过9mg/L这一阈值后呈下降趋势,NT在0─120mg/L和P_T在0─12mg/L范围内,SOD,丙二醛(MDA)与N、P浓度呈显著正相关;N、P能诱导产生新的同工酶带,苗高、可溶性蛋白分别与N、P浓度呈显著负相关. 相似文献
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邻苯二甲酸酯的生物降解研究 总被引:4,自引:1,他引:3
从处理焦化废水的活性污泥中,通过富集驯化培养,平板划线纯化,分离出了5株能有效降解邻苯二甲酸二丁酯(DBP)的菌株。利用摇瓶实验,对各菌株的降解能力进行了比较,研究了菌株的生长特性和降解过程动力学。结果表明,邻苯二甲酸二丁酯的生物降解过程可用Monod方程描述,其动力学参数μm和Ks分别为0.4h^-1和28mg/L。 相似文献
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不完全厌氧一好氧同反应器工艺是通过时段切换在同一反应器内实现印染废水处理的过程。结果表明,反应器体积为30L,水力停留时间为12h总CODcr去除率达85%,总BOD5达94.3%,总色度为87.5%,处理出水CODcr为140mg/L,BOD5为8mg/L,色度为50倍,达到了国家二级排放标准,实验表明,经厌氧时间段后,BOD5/CODcr由0.15提高到0.37,色度由400倍降至50倍,为好 相似文献
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饱和带有机污染物的厌氧反硝化微生物降解 总被引:4,自引:0,他引:4
以卤代烃和芳香烃为代表,通过室内实验模拟饱和带厌氧反硝化环境,对地下饱和带中有机污染物的厌氧反硝化可生物降解性,降解机理,降解动力学方程等进行了研究。实验结果表明,芳香烃较卤代烃易被微生物降解,在有低学葡萄糖存在时有 机物的最大生物降解速率C6H6:Lmax=17mg/(m^2.d),C7H8:Lmax=46mg/(m^2.d),CCl4;Lmax=7mg/(m^2.d),CHCl3:Lmax=6 相似文献
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Jiajun Chen Hao Wang Na Zhang 《Frontiers of Environmental Science & Engineering in China》2009,3(3):313-319
This investigation was carried out to establish a new domestic landfill gas (LFG) generation rate model that takes into account
the impact of leachate recirculation. The first-order kinetics and two-stage reaction (FKTSR) model of the LFG generation
rate includes mechanisms of the nutrient balance for biochemical reaction in two main stages. In this study, the FKTSR model
was modified by the introduction of the outflow function and the organic acid conversion coefficient in order to represent
the in-situ condition of nutrient loss through leachate. Laboratory experiments were carried out to simulate the impact of
leachate recirculation and verify the modified FKTSR model. The model calibration was then calculated by using the experimental
data. The results suggested that the new model was in line with the experimental data. The main parameters of the modified
FKTSR model, including the LFG production potential (L
0), the reaction rate constant in the first stage (K
1), and the reaction rate constant in the second stage (K
2) of 64.746 L, 0.202 d−1, and 0.338 d−1, respectively, were comparable to the old ones of 42.069 L, 0.231 d−1, and 0.231 d−1. The new model is better able to explain the mechanisms involved in LFG generation. 相似文献
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Utilizing surfactants to control the sorption, desorption, and biodegradation of phenanthrene in soil-water system 总被引:1,自引:0,他引:1
An integrative technology including the surfactant enhanced sorption and subsequentdesorption and biodegradation of phenanthrene in the soil-water system was introduced and tested. For slightly contaminated agricultural soils, cationic-nonionic mixed surfactant- enhanced sorption of organic contaminants onto soils could reduce their transfer to plants, therefore safe-guarding agricultural production. After planting, residual surfactants combined with added nonionic surfactant could also promote thedesorption and biodegradation of residual phenanthrene, thus providing a cost-effective pollution remediation technology.0ur results showed that the cationic-nonionic mixed surfactantsdodecylpyridinium bromide (DDPB) and Triton X-100 (TX100) significantly enhanced soil retention of phenanthrene. The maximum sorption coefficient Kd* of phenanthrene for contaminated soils treated by mixed surfactants was about24.5 times that of soils without surfactant (Kd ) and higher than the combined effects of DDPB and TX100 individually, which was about 16.7 and 1.5 times Kd , respectively.0n the other hand, TX100 could effectively remove phenanthrene from contaminated soils treated by mixed surfactants, improving the bioavailability of organic pollutants. Thedesorption rates of phenanthrene from these treated soils were greater than 85% with TX100 concentration above2000 mg/L and approached 100% with increasing TX100 concentration. The biodegradation rates of phenanthrene in the presence of surfactants reached over 95% in30days. The mixed surfactants promoted the biodegradation of phenanthrene to some extent in 10-22days, and had no obvious impact on phenanthrene biodegradation at the end of the experiment. Results obtained from this study provide some insight for the production of safe agricultural products and a remediation scheme for soils slightly contaminated with organic pollutants. 相似文献
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A new technique whereby cellulase immobilized on aminated silica was applied to catalyze the degradation of dicofol, an organochlorine pesticide. In order to evaluate the performance of free and immobilized cellulase, experiments were carried out to measure the degradation efficiency. The Michaelis constant, Km, of the reaction catalyzed by immobilized cellulase was 9.16 mg/L, and the maximum reaction rate, Vmax, was 0.40 mg/L/min, while that of free cellulase was Km = 8.18 mg/L, and Vmax = 0.79 mg/L/min, respectively. The kinetic constants of catalytic degradation were calculated to estimate substrate affinity. Considering that metal ions may affect enzyme activity, the effects of different metal ions on the catalytic degradation efficiency were explored. The results showed that the substrate affinity decreased after immobilization. Monovalent metal ions had no effect on the reaction, while divalent metal ions had either positive or inhibitory effects, including activation by Mn2 +, reversible competition with Cd2 +, and irreversible inhibition by Pb2 +. Ca2 + promoted the catalytic degradation of dicofol at low concentrations, but inhibited it at high concentrations. Compared with free cellulase, immobilized cellulase was affected less by metal ions. This work provided a basis for further studies on the co-occurrence of endocrine-disrupting chemicals and heavy metal ions in the environment. 相似文献
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Zhaoming Zheng Jun LiJing M Jia DuFan Wang Wei BianYanzhuo Zhang Baihang Zhao 《环境科学学报(英文版)》2017,29(3):60-67
The aim of the present work was to evaluate the anaerobic ammonium oxidation (anammox) activity of simultaneous partial nitrification, anammox and denitrification (SNAD) biofilm with different substrate concentrations and pH values. Kaldnes rings taken from the SNAD biofilm reactor were incubated in batch tests to determine the anammox activity. Haldane model was applied to investigate the ammonium inhibition on anammox process. As for nitrite inhibition, the NH4+-N removal rate of anammox process remained 87.4% of the maximum rate with the NO2−-N concentration of 100 mg/L. Based on the results of Haldane model, no obvious difference in kinetic coefficients was observed under high or low free ammonia (FA) conditions, indicating that ammonium rather than FA was the true inhibitor for anammox process of SNAD biofilm. With the pH value of 7.0, the rmax, Ks and KI of ammonium were 0.209 kg NO2−-N/kg VSS/day, 9.5 mg/L and 422 mg/L, respectively. The suitable pH ranges for anammox process were 5.0 to 9.0. These results indicate that the SNAD biofilm performs excellent tolerance to adverse conditions. 相似文献
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R. Rajesh Kannan M. Rajasimman N. Rajamohan B. Sivaprakash 《Frontiers of Environmental Science & Engineering in China》2010,4(1):116-122
In this study, the biosorption of Malachite green (MG) onto Turbinaria conoides, brown marine algae, was studied with respect
to initial pH, temperature, initial dye concentration, and sorbent dosage. The optimum initial pH and temperature values for
MG removal were found to be 8.0 and 30°C, respectively. Sorbent dosage was found to strongly influence the removal of MG.
Equilibrium studies were carried out to test the validity of the Langmuir (q
max = 66.6 mg/g and b = 0.526 mL mol/L) and the Freundlich (n = 1.826 and K = 3.751 mg/g) isotherms. The kinetic studies indicated the validity of the pseudo first-order and second-order equation. 相似文献
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MBR污水处理工艺中活性污泥动力学参数测定 总被引:5,自引:1,他引:4
缺乏可靠的污泥动力学设计参数是膜-生物反应器(membrane bioreactor,MBR)工艺在实际应用中遇到的主要问题之一.以某座处理城市污水的实际规模MBR工程的好氧活性污泥为对象,采用耗氧速率表征方法,测定计算得到以下动力学参数值:异养菌产率系数YH=0.693、自养菌产率系数YA=0.263、异养菌衰减系数KdH=0.108 d-1、自养菌衰减系数KdA=0.089 d-1、COD最大比去除速率vmS=1.94 mg·(mg·d)-1、COD去除半饱和常数KS=34.6 mg·L-1、氨氮最大比去除速率vmN=0.18 mg·(mg·d)-1、氨氮去除半饱和常数KN=1.06 mg·L-1.以上结果与传统活性污泥法工艺(CAS)中污泥的文献报道值相比,YH和KdH较高,而vmS和vmN较低.MBR的高污泥浓度条件可能是导致上述差异出现的主要原因. 相似文献