煤礦排水沉淀物作為一種新的吸附劑對重金屬吸附作用的動力學(xué)與熱力學(xué)研究

1、Kinetic and thermodynamic studies of the adsorption Kinetic and thermodynamic studies of the adsorption of heavy metals on to a new adsorbent:of heavy metals on to a new adsorbent:coal mine drainage sludgecoal mine drainage sludge煤礦排水沉淀物作為一種新的吸附劑對煤礦排水沉淀物作為一種新的吸附劑對重金屬吸附作用重金屬吸附作用的動的動力學(xué)與熱力學(xué)研究力學(xué)與熱力學(xué)研究AB

2、STRACT摘要 In this study, we investigated the application of sludge waste obtained from a coal mine drainage treatment facility that treats acid mine drainage (designated as AMD) from metal-mine water. The coal mine drainage sludge (designated as CMDS), which contained 70% goethite and 30% calcite, wa

3、s utilized as a sorption material for Cu(II) and Zn(II) removal from an aqueous solution of metallic mine drainage.這本次研究中，我們研究了來自于煤礦處理廠的沉淀廢物的應(yīng)用，用這種沉淀廢物處理來自于金屬礦山排水中的酸性礦物廢水（簡稱為AMD）。這種煤礦排水沉淀物（簡稱為CMDS），它包含了70%的針鐵礦和30%的方解石，被利用作為一種吸附移除來自金屬礦山廢水中的Cu（II）和Zn（II）。 The equilibriums and kinetics were investigate

4、d during a series of batch adsorption experiments. The Langmuir model was used to fit the equilibrium data, resulting in the best fits. The removal efficiencies were controlled by solution pH, temperature, initial concentration of heavy metal, sorbent amount and contact time. The pseudo-second-order

5、 kinetic model was used to fit the kinetic data, providing a good correlation with the experimental data.在整個分批吸附實驗中都用到了熱力學(xué)和動力學(xué)平衡的研究。結(jié)果顯示：Langumir模型能夠很好的擬合熱力學(xué)平衡數(shù)據(jù)。整個吸附過程中移除效率由溶液的pH值，溫度，重金屬溶液的初始濃度，吸附劑數(shù)量以及接觸時間所控制。而擬二級動力學(xué)方程能夠很好的擬合動力學(xué)數(shù)據(jù)，并且顯示了與實驗數(shù)據(jù)的一個很好的關(guān)聯(lián)度。 The results of a thermodynamic study showed tha

6、t the activation energies (EA) were 3.75 and 1.75 kJ mol1for the adsorption of Cu(II) and Zn(II)on to CMDS at pH 5.5. These values of activation energy could correspond to physisorption. The positive values obtained for both the standard enthalpy change,0, and the standard entropy change,S0, suggest

7、 that the adsorption of Cu(II) and Zn(II) on to the CMDS was an endothermic reaction and that randomness increased at the solidliquid interface during the adsorption of Cu(II) and Zn(II) on to the CMDS. The adsorption process also followed a pseudo-second-order kinetic model.本次熱力學(xué)研究表明：吸附劑CMDS在pH=5.5

8、時，對Cu（II）和Zn（II）的吸附的活化能（EA）為3.75和1.75 KJ mol-1。這些活化能量對于物理吸附式由價值的。而這各數(shù)據(jù)的得出對于標(biāo)準(zhǔn)焓變0 和標(biāo)準(zhǔn)熵變S0提供了一定的價值，表明：吸附劑CMDS對于Cu（II）和Zn（II）的吸附是一個吸熱反應(yīng)，并且表明：吸附劑CMDS對于Cu（II）和Zn（II）的吸附過程在固-液界面的隨機(jī)性有所增加。這個吸附過程仍然符合擬二級動力學(xué)方程。INTRODUCTION介紹 Acid mine drainage (AMD) released from abandoned gold mines can not only pollute natur

9、al environments such as surrounding soils, surface and ground waters, but also has some sequential toxic effects on crops and humans through concentration through the food chain 1. Although the most widespread method to remove heavy metals in AMD is coagulation and flocculation through neutralizatio

10、n by increase of pH, it is not very economic or effective, and can also release secondary pollution.從金礦中隨意排放 AMD不僅能污染環(huán)境例如周圍的土壤環(huán)境，表明和地下水，而且能夠通過食物鏈對農(nóng)作物和人類產(chǎn)生連續(xù)的毒性效應(yīng)。盡管去除重金屬廢水中的AMD的大多數(shù)方法是利用化學(xué)中和反應(yīng)通過控制pH的增加來形成凝結(jié)物或者是絮凝產(chǎn)物，但是這種方法并不是很經(jīng)濟(jì)和有效，并且會產(chǎn)生二次污染。Accordingly, other treatment methods have been extensively s

11、tudied. Among them, adsorption techniques have been studied, using metal oxide, active carbon, fly ash, peat, activity sludge and waste sludge 25. In particular, research has been conducted on the adsorption of heavy metals by the use of iron compounds including ferric saltsand zero valent iron (ZVI

12、) 6,7. The adsorption of cationic heavy metal species on the hydroxyl group of sorbents has been found to be an endothermic reaction in an adsorption study of heavy metals using goethite (FeOOH). 因此，其他的處理方法被廣泛的研究。其間，化學(xué)吸附技術(shù)也被研究，通過利用金屬氧化物，活性碳粉塵灰，泥煤，活躍沉淀物和廢物泥。特別是通過研究利用鐵化合物包括鐵鹽和零化合價鐵（ZVI）來吸附重金屬。在用針鐵礦（Fe

13、OOH）作為吸附劑吸附重金屬離子的實驗中，是將陽離子金屬吸附在吸附劑的羥基上，并且該實驗屬于吸熱反應(yīng)。 Thus, the adsorption capacities and equilibrium constants increase as the temperature increases 815.The relationship between pH and adsorption and/or coprecipitation, using goethite for the removal of heavy metals, has also been actively studied 16

14、. The different ratios of each hydroxyl group (FeOH2+ , FeOH, FeO) may depend on the pH. In contrast, clay minerals such as bentonite show a clarification reaction, in which their equilibrium constants and adsorption capacities decrease with an increase in temperature as a result of the exothermic n

15、ature of metal adsorption 17.因此，當(dāng)隨著溫度的增加，吸附能力和平衡常數(shù)也隨著增加。在用鐵針石對重金屬進(jìn)行移除期間，pH和吸附以及/或者共同沉淀的關(guān)系也有很多的研究。而每個羥基的不同配比可能取決于pH。與此相反，例如膨潤土的黏土礦物卻顯示出了一種澄清反應(yīng)，在反應(yīng)中平衡常數(shù)和吸附容量隨著溫度的增加而減少是由于金屬吸附的放熱特性所導(dǎo)致的結(jié)果。 In this study, the adsorption characteristics of coal mine drainage sludge (CMDS) for heavy metals in AMD released

16、from a metal-mine area were investigated.The CMDS contains mainly Fe2O3(64.7%) and has been produced by drying the sludge cake produced from an electric purification facility in Korea. The Fe hydroxide/oxide of CMDS is usually amorphous and has amphiphilic adsorption characteristic for both cationic

17、 heavy metals and anionic metalloids. Thus, the application of sludge as a sorption material for treating AMD of metal mines could have an economic potential in terms of recycling waste material.在本次研究中，關(guān)于吸附劑CMDS對于從金屬礦山區(qū)域中排放的AMD中的重金屬吸附的吸附特性是研究過的。吸附劑CMDS主要包含了64.7%的Fe2O3和在位于韓國的一個電動凈化廠產(chǎn)生的已經(jīng)干燥的污泥餅。在CMDS中

18、的Fe的氫氧化物/氧化物通常是無定型的并且對于陽離子重金屬和陰離子非金屬有兩親性的吸附特性。因此，將沉淀物作為吸附材料對金屬礦山的AMD進(jìn)行處理在廢物資源回收方面可能會有經(jīng)濟(jì)上的潛在性。 The objective in this study was to investigate the adsorption, in terms of reaction speed and thermodynamics, of the main heavy metals in the AMD releasedfrom metal mines-Cu(II) and Zn(II)-on to CMDS.本次實驗的目

19、的是為了研究在吸附中的反應(yīng)速度和利用吸附材料CMDS吸附在從金屬礦山中排放的AMD中的Cu（II）和Zn（II）的熱力學(xué)特性。EXPERIMENTAL實驗EXPERIMENTALWATER AND SLUDGE SAMPLES水和沉淀物的樣品 Water was sampled from the effluent of three settling tanks that were previously setup to remediate AMD of a metal mine located at 351823.2 longitude and1291339.1 latitude in Sou

20、th Korea. The CMDS was simply prepared by drying at 25 the sludge taken from an electric purification facility treating acidic mine drainage from a coal mine.水樣是從三個不同的沉淀池提取的，這三個沉淀池提前建立去修復(fù)位于韓國的經(jīng)度為351823.2和緯度1291339.1 的金屬礦山中的AMD。CMDS是來自于一個通過電動凈化廠處理來自煤礦中的酸性礦山排水，僅僅在25通過干燥制成的污泥餅。EXPERIMENTALANALYSES分析 Th

21、e surface area of CMDS was analysed by the Brunauer Emmett Teller (BET, ASAP 2010, Micromeritics Inc., USA) adsorption method using nitrogen gas (Sutosorb-1-C, Chemisorptions-Physisorption Analyser,Quantachrome Instruments, USA). The pH of water was measured with a Thermo Orion model 420A+, and heav

22、y metals were analysed by an inductively coupled plasma atomic emission spectrometer (ICP-AES, 5300DV, Perkin Elmer). X-ray diffraction (XRD,Xpert PRO/MRO, Philips) analyses were conducted for the selected freeze-dried powdered samples of CMDS by use of a PANalytical XPert Pro diffractometer (fitted

23、 with an XCelerator) with a CuK radiation source at a scan speed of 2.5min1.材料CMDS的曲面面積通過Brunauer Emmett Teller吸附方法利用氮?dú)?進(jìn)行了的分析。樣品水的值通過型號為420A+熱電奧利龍的儀器進(jìn)行測試，并且通過ICP-AES分析了重金屬離子的含量。XRD設(shè)備被用來測定經(jīng)過冷凍干燥過的CMDS樣品，所用的衍射儀為PANalytical XPert Pro，輻射源為Cu的Ka射線，轉(zhuǎn)速為每分鐘2.5。 The phase identification of CMDS was carried

24、out by the means of the XPert accompanying software program, High Score Plus, and the reference intensity ratio method (RIR method) ICDD PDF-4+ database (International Centre for Diffraction Database, USA, 1999). The X-rayfluorescence (XRF-1700/SHIM ADZUXRF) results showed that the CMDS was mainly c

25、omposed of SiO2(6.65%), Fe2O3(64.74%) and CaO(8.6%). These compounds exceeded 79.9%.對于CMDS的相位鑒別是通過XPert附帶的軟件High Score Plus和參考強(qiáng)度比率方法ICDD-PDF+數(shù)據(jù)庫方法進(jìn)行的。X射線熒光結(jié)果顯示CMDS主要包含了6.65%二氧化硅，64.74%的三氧化二鐵和8.6%的氧化鈣。這些化合物超過了79.9%。 The buffer capacity of the sludge was measured as follows: 10 g of sludge and 25 mL o

26、f deionized water were added to a 50 mL centrifuge tube. Then different amounts of 0.1 M HCl were added to each sample and the suspensions were shaken at room temperature for 24 h prior to pH measurement 2,19. The sludge was reacted with 2 M HCl to dissolve the carbonate. The remaining acid was titr

27、ated using 0.1 M NaOH to measure the CaCO3 content of the CMDS 19. The easily extractable fractions of Fe and Mn from the CMDS could be analysed with the following methods. After extraction with 1 M hydroxylamine hydrochloride(NH2OHHCl), the Fe content of the CMDS was measured by ICP 20.沉淀物的緩沖容量通過測定

28、：10g沉淀物和25ml去離子水加入到50ml離心管中。然后將不同量的0.1mol HCl溶液加入到每個樣品中，并且將懸浮液在pH測量前在室溫下振蕩24小時。沉淀物與2mol的 HCl反應(yīng)使碳酸鹽溶解。其余的酸用0.1mol的NaOH進(jìn)行滴定去測量CMDS中含有的CaCO3含量?？珊苋菀椎膹倪@個方法分析出CMDS中少量的Fe和Mn元素。之后提取1mol的羥胺鹽酸鹽，通過ICP測量出CMDS中的Fe元素。 The Mn ions in the CMDS were dissolved using 0.1 M hydroxylamine hydrochloride and analysed by I

29、CP 21. The organic carbon content and cation exchange capacity (CEC) of the CMDS were measured by the WalkleyBlack method and the ammonium acetate method, respectively. For the ammonium acetate method, the CMDS was treated with a salt of NH4+ ion and then NH4+ ions were substituted using a NaCl solu

30、tion. The replaced amount of NH4+ ions was analysed. Loss-on-ignition (LOI) of the CMDS was measured as follows: 1020 g of wet CMDS was dried at 105C for 18 h, and then heated at 450C for 6 h. During this procedure, the sample at each step was weighed 1.在CMDS中的Mn離子通過用0.1mol的羥胺鹽酸鹽去除并且用ICP進(jìn)行分析。CMDS的有機(jī)

31、碳含量和陽離子交換能力（CEC）分別通過WalkleyBlack和醋酸銨方法進(jìn)行測定。對于醋酸銨方法，CMDS用含NH4+的鹽處理并且之后的NH4+用NaCl溶液進(jìn)行替換。分析被替換的NH4+。CMDS的燒失量（LOI）用一下方法進(jìn)行測定：在105下干燥10-20g的濕CMDS 18小時，然后在450下加熱6小時。干燥過程中每一步都要稱量。EXPERIMENTALADSORPTION STUDY吸附研究 The adsorption study was conducted in batch tests. A different mass of CMDS (5, 10, 20, 30 or 40

32、 g) was added to 500 mL of mine water; the bottles containing these slurries were shaken on a shaker (150 rpm) for24 h at 252C. After filtering the supernatant, the concentrations of copper, zinc and iron in the filtrates were measured. Copper, zinc and iron sorption data were analysed using the Lan

33、gmuir model to evaluate the parameters directly associated with the sorption process. The Langmuir model equation is by represented by: 吸附研究是批量試驗。不同質(zhì)量的CMDS（5,10,20,30或40g）被加到500ml的金屬溶液中；包含這些泥漿的瓶子被放在振蕩器（150r/min）中在252下振蕩24小時。之后二次過濾懸浮液，測量在濾液中的Cu、Zn、Fe離子濃度。 銅、鋅和鐵吸附數(shù)據(jù)進(jìn)行分析利用Langumir模型評價參數(shù)與吸附過程直接相關(guān)。Langum

34、ir模型表達(dá)式為：EXPERIMENTALKINETIC TESTS動力學(xué)實驗 Adsorption kinetic tests were conducted to find out the adsorption behaviours such as maximum sorption capacity and energy of heavy metals for the sludge. A different mass of CMDS (5, 10, 20, 30 or 40 g) wasadded to 500 mL of mine water. Then, each of the susp

35、ensions was shaken at 150 rpm at different temperatures (278 K, 288 K, 298 K, or 308 K) without pH adjustment. After 24 h (more than the time required for equilibrium) of shaking, 5 mL of supernatant was withdrawn and centrifuged prior to analysis.吸附動力學(xué)實驗旨在為了發(fā)現(xiàn)吸附行為例如：最大吸附容量和對于沉淀物吸附重金屬的能量。不同質(zhì)量的CMDS （

36、5,10,20,30或40g）被加到500ml的金屬溶液中，然后，每一個懸浮液在不同溫度（ 278 K, 288 K, 298 K, 或 308 K ）下以150r/min進(jìn)行振蕩吸附。24小時（超過這個時間后已經(jīng)平衡）的振蕩后，取出5ml懸浮液并且在分析前離心處理。 The pseudo-second-order kinetic equation has been extensively used to obtain more reliable kinetic constants for heterogeneous adsorption of heavy metals22. To inves

37、tigate the mechanism of sorption and the rate constants for the adsorption of Cu(II) and Zn(II) on to CMDS, the pseudo-second-order kinetic equation was used as shown below 23. The differential equation is as follows:Integrating Equation (2) for the boundary conditions t =0 to t, and qt= 0 to qt, gi

38、ves:擬二級動力學(xué)方程被廣泛用于獲得更可靠的異類重金屬吸附的動力常數(shù)。為了研究吸附機(jī)理和CMDS對Cu（II）和Zn（II）的吸附速率常數(shù)，擬二級動力學(xué)方程在下面提到。它的不同形式為：綜合化方程（2）的邊界條件為t=0到t，qt=0到qt，給出：When Equation (3) is linearized, it gives:where v0(mg g1min1) is the initial sorption rate; therefore, the v0and qe values of the kinetic tests can be determined experimentally

39、 by plotting t versus t/qt; qe is the amount of Cu(II) and Zn(II) adsorbed at equilibrium(mg L1); qt is the amount of Cu(II) and Zn(II) adsorbed at time t (mg g1); and K2is the rate constant of the pseudo-second-order kinetic equation (g mg1min1).The pseudo-second-order kinetic rate constant (K2) is

40、 expressed as a function of temperature by the following Arrhenuius type relationship 24:當(dāng)公式（3）被線性化，得到（4）和（5）。其中：v0為初始吸附速率；因此，v0和qe在動力學(xué)中可作為對實驗中測量到的數(shù)據(jù)t/qt的驗證。qe是Cu（II）和Zn（II）在時間t內(nèi)被吸附的數(shù)量；K2為擬二級動力學(xué)方程的速率常數(shù)。擬二級動力學(xué)方程速率常數(shù)（K2）可以通過阿倫尼烏斯方程以溫度為根據(jù)表達(dá)出來。EXPERIMENTALTHERMODYNAMIC PARAMETERS熱力學(xué)參數(shù) To explain the eff

41、ect of temperature on the adsorption thermodynamic parameters, standard free energyG0, standard enthalpyH0, and standard entropy S0 were determined. The thermodynamic parameters can be determined from the variation in the thermodynamic equilibrium constant K0, which can be defined as follows 25,26:

42、where Ce is the concentration of heavy metals in solution at equilibrium (mg L1), and qe is the surface concentration of heavy metals adsorbed in the sorbent (mg g1). The adsorption standard free energy changes (G0) can be calculated from:為了解釋溫度在吸附熱力學(xué)參數(shù)、標(biāo)準(zhǔn)自由能G0，標(biāo)準(zhǔn)焓變H0以及標(biāo)準(zhǔn)熵變S0中的作用。熱力學(xué)參數(shù)從熱力學(xué)的變化中決定的平衡常

43、數(shù)K 0 ,而K0由（7）式給出。其中：Ce為反應(yīng)平衡后重金屬在溶液中的濃度。qe為吸附劑表面吸附的重金屬的濃度。吸附標(biāo)準(zhǔn)自由能變由（8）式給出。 where R is the universal gas constant (8.314 J mol1K1) and T is the temperature in Kelvin. The average standard enthalpy change (H0) is determined from the vanHoof equation:其中：R為普遍氣體參數(shù)，T為開爾文溫度。平均自由焓變H0由范德霍夫方程給出。RESULTS AND DIS

44、CUSSION結(jié)果與討論RESULTS AND DISCUSSIONCHARACTERIZATION OF THE AMD AND CMDSAMD 和CMDS 的特性 The physico-chemical properties of the AMD and CMDS are shown in Tables 1 to 4. The initial concentrations of Cu, Zn, and Fe were 10, 9.2 and 58 mgL1,respectively, and the pH (2.65) was acidic. Owing to the low pH an

45、d the high concentration of Fe, the acidity was high at 288 mg as CaCO3/L. The BET surface area and pH of the CMDS were 151 m2g1and 8.3, respectively. The buffer capacity of the CMDS was 82.3 mmol H+kg1pH1. X-ray diffraction (XRD) analyses and the RIR method ICDD PDF-4+ database showed that the CMDS

46、 mainly consisted of goethite and calcite. The composition ratio of goethite (reference code No: 010-81-0463) and calcite (reference code No: 010-81-02027) were 70% and 30% by weight, respectively.AMD和CMDS的物理-化學(xué)性能在表1到表4中給出。Cu, Zn,和Fe的初始濃度為10,9,2和58ppm，pH為2.65為酸性。由于Fe處于低pH和高濃度環(huán)境中，而CaCO3為288ppm。CMDS的比

47、表面積和pH分別為151m2/g和8.3。CMDS的緩沖容量為82.3 mmol H+/kg/pH。XRD分析和RIR方法的ICDD PDF-4+數(shù)據(jù)庫表明：CMDS主要針鐵礦和方解石構(gòu)成。針鐵礦和方解石的成分比例按質(zhì)量算為70%和30%。 The most interesting aspect of this analysis is that the average pore sizes of the CMDS were in the range of mesopores. Porous materials can be classified by IUPAC as follows: mic

48、roporous (50.0 nm) 27. Macroporous materials are restricted for use as adsorbents because of their nonuniformity of pore size distribution and low surface area. Microporous materials have some limits regarding accessibility to the active surface area because of blocking problems. Regardless of seaso

49、n, the measured pore size (67.92 ) of the CMDS was in the mesopore range, which could have a low diffusion limit. Therefore, a sorption material that is well developed with mesopores could have a reduced adsorption equilibrium since adsorbate could easily adsorb on the sorption sites.這次分析中最為有趣的是CMDS

50、的孔隙尺寸是在中孔范圍內(nèi)。多孔材料由IUPAC分類為：微孔（50.0 nm）。大孔材料作為吸附材料是受限制的，因為它們的孔徑分布的不均勻性和低表面積。微孔材料因為阻塞問題，活性表面積的可及性上有一些限制 。忽視季節(jié)問題，CMDS的孔徑測量為67.92 為中孔材料，對此它有較低的擴(kuò)散限制。因此，一個吸附材料, 中孔發(fā)達(dá)可以降低吸附平衡，因為被吸附物很容易吸附在吸附位上。RESULTS AND DISUSSIONADSORPTION KINETICS吸附動力學(xué) Figure 1 shows the adsorption kinetics results for Cu(II), Zn(II), an

51、d Fe(III) in the AMD at different amounts of CMDS. When the concentration of CMDS was more than 5 g, about 100% of Cu(II), Zn(II), and Fe(III) were removed within 10 min, whereas, when 5 g of CMDS was applied, about 100% of Cu(II) and Zn(II) was removed within 100 min and 100% of Fe(III) was remved

52、within 20 min. But the copper, zinc and iron recovery decreased with increasing contact time. The Cu(II) and Zn(II) was completely removed by about 180 min of operation using 5g CMDS, while about 20 min was needed for Fe(III). Probably, the rapid removal of Fe(III) could be explained by the simultan

53、eous mechanism of hydrolysis and coagulation occurring at high pH. 圖1描述了用不同質(zhì)量的CMDS吸附AMD中的Cu(II), Zn(II)，和Fe(III)的吸附動力學(xué)結(jié)果。當(dāng)CMDS的質(zhì)量超過5g時，大約有100%的Cu(II), Zn(II)，和Fe(III)在10min內(nèi)被移除，然而，當(dāng)CMDS質(zhì)量為5g時，約有100%的Cu(II), Zn(II)，在100min內(nèi)移除，而100%的Fe(III)在20min內(nèi)被移除。但是,銅、鋅和鐵恢復(fù)隨接觸時間增加而降低。 對于Cu(II) 和 Zn(II) ，5g的CMDS在18

54、0min時完全移除，而對于Fe(III)只需要20min。可能,在快速去除Fe(III)的時候，在高pH時可以用同時發(fā)生了水解反應(yīng)和凝固反應(yīng)來解釋。 In general, the soluble Fe(III) transforms into insoluble forms by a polymerization reaction at higher pH, whereas Cu(II) and Zn(II) are predominantly removed by the adsorption mechanism. The Langmuirtreatment is based on the

55、 assumption that maximum adsorption corresponds to a saturated monolayer of adsorbate molecules on the adsorbent surface, that the energy of adsorption is constant, and that there is no transmigration of adsorbate molecules in the plane to the surface 25. 通常來說，可溶解的Fe(III)在高pH時通過聚合反應(yīng)而變成了不溶解的一種形式。而對于C

56、u(II)和 Zn(II) 而言，很顯著的因為吸附機(jī)理而被移除。Langumir模型是基于假設(shè)最大吸附對應(yīng)于一個吸附分子的飽和單層的吸附劑表面,吸附的能量是恒定的，并且表面平面上沒有其他的吸附物顆粒。 Figure 2 shows the adsorption amount vs. the maximum adsorption capacity rate when the CMDS weight reached the equilibrium state. When the CMDS weight was 5 g, the adsorption capacity rate of Cu and

57、Fe was 100% and when the CMDS weight was 10 g, the adsorption capacity rate of Zn showed 100%. These results are the same as in Figure 1 in that the maximum adsorption capacity rate was reached at the equilibrium state.圖2描述了，當(dāng)CMDS的重量達(dá)到平衡狀態(tài)時，吸附量和最大吸附量的比值。當(dāng)CMDS的重量為5g時，對Cu和Fe的吸附量的比值達(dá)到100%，當(dāng)CDMS的重量達(dá)到10g

58、時，對Zn的吸附量的比值達(dá)到100%。這些結(jié)果與圖1所示的達(dá)到平衡態(tài)的最大吸附容量速率是相同的。 Figure 3 shows the initial sorption rate vs. CMDS weight. The initial sorption rates of Cu and Zn corresponded to the pseudo-second-order kinetic model whereby the rates increased when CMDS weight increased. In the case of Fe, the sorption occurred ra

59、pidly. The initial sorption rate of Fe increased when the CMDS weight increased, but after the sorption reached 100% the initial sorption rate decreased. 圖3描述了，初始吸附速率和CMDS質(zhì)量的比值。當(dāng)隨著CMDS的質(zhì)量增加而Cu和Zn的最初吸附速率也增加時，和擬二級速率方程模型有很好的擬合結(jié)果的。而對于Fe，吸附很迅速。當(dāng)CMDS的質(zhì)量增加時Fe的初始吸附速率也是增加的，但是之后吸附達(dá)到100%時初始吸附率開始降低。RESULTS AND

60、DISUSSIONEFFECT OF TEMPERATURE ON KINETICS溫度對動力學(xué)的影響 Figure 4 shows adsorption kinetics and plots of the linearized form of the pseudo-second-order kinetic model for Cu(II) and Zn(II) at 5, 15, 25 and 35C. Table 5 shows the parameters obtained from fitting the pseudo-second-order kinetic model. These