外文翻譯--利用一種新型納米復(fù)合吸附劑去除合成廢水中的重金屬（英文）

1、 Y. B. Onundi et al.Int. J. Environ. Sci. Tech., 8 (4), 799-806, Autumn 2011ISSN 1735-1472 © IRSEN, CEERS, IAU*Corresponding Author Email: mamun@iium.edu.myTel: +603 6196 4440, Fax: +603 6196 4442Received 10

2、November 2010; revised 27 March 2011; accepted 11 August 2011; available online 1 September 2011Heavy metals removal from synthetic wastewater by a novel nano-size composite adsorbent Y. B. Onundi; * A. A. Mam

3、un; M. F. Al Khatib; M. A. Al Saadi; A. M. Suleyman Bioenvironmental Engineering Research Unit, Department of Biotechnology Engineering, Faculty of Engineering, International Islamic University Malaysia, Gombak, 53100

4、 Kuala Lumpur, Malaysia ABSTRACT: The effects of varying operating conditions on metals removal from aqueous solution using a novel nano-size composite adsorbent are reported in this paper. Characterization of the compos

5、ite adsorbent material showed successful production of carbon nanotubes on granular activated carbon using 1 % nickel as catalyst. In the laboratory adsorption experiment, initial mixed metals concentration of 2.0 mg/L C

6、u2+, 1.5 mg/L Pb2+ and 0.8 mg/L Ni2+ were synthesized based on metals concentration from samples collected from a semiconductor industry effluent. The effects of operation conditions on metals removal using composite ads

7、orbent were investigated. Experimental conditions resulting in optimal metals adsorption were observed at pH 5, 1 g/L dosage and 60 min contact time. It was noted that the percentage of metals removal at the equilibrium

8、 condition varied for each metal, with lead recording 99 %, copper 61 % and nickel 20 % , giving metal affinity trend of Pb2+ > Cu2+ > Ni2+ on the adsorbent. Langmuir’s adsorption isotherm model gave a higher R2 va

9、lue of 0.93, 0.89 and 0.986 for copper, nickel and lead, respectively, over that of Freundlich model during the adsorption process of the three metals in matrix solution.Keywords: Adsorption; Carbon nanotubes; Granular a

10、ctivated carbon; IsothermINTRODUCTIONIndustrialization, uncontrolled use and exploitation of natural resources of the past decades have resulted in increased pollution of the Earth (Bansal and Goyal, 2005). Pollution of

11、 the environment by heavy metals is of great concern to governments and environmentalists due to their detrimental effect on a variety of living species (Issabayeva et al., 2007). Pollution of the environment in Malaysia

12、 by heavy metals is mainly by electroplating and metal treatment / fabrication industries located in the west coast of the peninsular Malaysia (DOE, 1979; Issabayeva et al., 2007). Research on finding more efficient tech

13、nology for wastewater treatment to meet prevalent safe standards is constantly receiving the attention of environmental scientists around the world. Previous wastewater treatment efforts had led to the development of var

14、ious treatment technological options which involved the application of unit operations or unit processes such as chemical precipitation, coagulation, adsorption, ion exchangeand membrane filtration (Georg and Max, 2008).

15、 Furthermore, among aforementioned treatment technologies, adsorption had been reported as the most technically and economically viable option (Onundi et al., 2010). Furthermore, research in wastewater treatment by adsor

16、ption has resulted in development of different materials for removal of metals from solutions, these materials include: natural product (Nouri et al., 2009; 2011), activated carbon (Issabayeva et al., 2006; Onundi et al.

17、, 2010), zeolites, aluminosilicate (Samuel and Osman, 1987), peat kaolin and clay (Chantawong et al., 2003) and polysaccharides (Bong et al., 2004). Recently, Carbon nanomaterials (CNMs) mainly in the form of Carbon nano

18、tubes (CNTs) and Carbon nanofibers (CNFs) are being used as new adsorbents with superior performance due to their high specific surface area and high aspect ratio. Work on the effect of morphology, surface functional gro

19、ups on adsorption capacity of heavy metals by CNMs had been carried out (Nora and Mamadou, 2005; Kabbashi et al., 2009; Atafar et al., 2010). Work of Li et al. (2003) reported Multiwall carbon nanotubes (MWCNTs) as havin

20、g metal-ionY. B. Onundi et al.801Int. J. Environ. Sci. Tech., 8 (4), 799-806, Autumn 2011industrial wastewater metal concentration and added to a calculated amount of adsorbent in 100 mL shake flask. The pH adjustment o

21、f solution was done using 1.0 M HCL and 1.0 M NaOH. The adsorbent in solution was agitated in a mechanical shaker at a speed of 100 rpm at 27 °C (±2). Blank solutions were treated similarly without the adsorben

22、t and under control condition as suggested by Goel et al. (2005). The solution was filtered using a Whatman® 0.45µm filter paper. The results were analyzed for the residual concentration of metals in the filtra

23、te by Atomic adsorption spectrophotometer (ASS) model HGA900. Equilibrium concentration of metals at different adsorbent dosage (1, 2, 3 and 4 g/L) at ambient temperature was used for the isotherm study. Isotherm studi

24、es at equilibrium constant concentration of metals was investigated using the two most widely used model equations of Freundlich (Freundlich and Hatfield, 1926)and Langmuir (Langmuir, 1918).RESULTS AND DISCUSSIONThe macr

25、o size composite CNT-GAC was easier to handle in the laboratory than the pure CNT. It was observed that the filtrate after adsorption experiment was clear, having no visible CNT-GAC remaining in solution. This indicates

26、that the macro size composite CNT-GAC retained the CNT on the GAC surface after adsorption, reducing membrane fouling, solving the separation problems earlier recorded in literature and also eliminating the need to centr

27、ifuge the filtrate before using the AAS machine.Fig. 1: FESEM Image of GAC surface Fig. 2: FESEM Image of CNT grown on GAC surfaceNONE SEI 10.0kV X100,000 100nm WD 7.5mm NONE

28、 SEI 10.0kV X100,000 100nm WD 7.5mm52.2 nm57.9 nm 56.6 nm51.8 nmPhysical and chemical characterization of the adsorbent The surface of the substrate GAC before the growth of CNT was large

29、ly porous as shown in Fig.1. The morphology of the CNT-GAC as observed by FESEM machine in Fig. 2 shows that the structures were twisted with a rough surface, having average outer diameter of 50 nm. The TEM images as sho

30、wn in Fig. 3 and 4 revealed the morphology of the CNT-GAC as MWCNT with average internal hollow diameter of 30 nm, with a caped end. This observed structure of CNT on the GAC is inline with the observation reported by Sh

31、oushan et al. (1999), Chai-chih et al. (2008) and Zhang et al. (2008) when CNT was produced at same temperature range. Other properties of the substrate GAC and the produced CNT-GAC are shown in Table 1. The FTIR analys

32、is of CNT-GAC is shown in Fig. 5and a summary of the peaks and their assignments are given in Table 2. As can be inferred from the FTIR analysis, the acidic functional groups were: carboxyl, carbonyl, lactones and sulphu

33、r groups. Generally, these acidic groups on carbon surface produce cation exchange properties (Goel et al., 2005; Edwin, 2008) and these had been reported to be responsible for higher adsorption of metal ions on carbon s