任秉雄王崇臣 ENVIRONMENTAL CHEMISTRY. 744 t 50% 10% 20% 1 mg L t S. SHZ-82 Spectrum-100 C 16 H 18 N 3 SCl 3H 2 O

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1 ENVIRONMENTAL CHEMISTRY Vol 32 No 8 August 2013 DOI /j issn * 张 1 佳 2 任秉雄王 3 鹏 1,3** 王崇臣 K Langmuir Freundlich Dubinin-Radushkevish Gibbs "G θ "H θ "S θ Langmuir Gibbs "G θ "H θ "S θ 1 1t 744 t 10% 20% 50% 2 1 mg L t S SHZ-82 Spectrum C 16 H 18 N 3 SCl 3H 2 O * PHR ZX ** Tel chongchenwang@ 126 com

2 < 0 59 mm 1 2 Spectrum cm - 1 KBr ml g L ml mg L mol L - 1 NaOH HCl ph 308 K 150 r min μm 662 nm A q = C 0 - C e V W 1 η = C 0 - C e 100% 2 C 0 q mg g - 1 C 0 mg L - 1 C e mg L - 1 V L W g 1 4 ph ph 8 g L mg L - 1 ph 5 5 ph μm 3 0 ml A ph g L mg L K 0 45 μm 3 0 ml A Langergren ln( q e - q ) t = lnq e - k 1 t 3 t = t 4 q t k 2 q 2 q e e 250 ml mg L g L K 150 r min - 1 q e K Langmuir Freundlich Dubinin-Radushkevish C e q e = 1 q max K L + C e q max 5 lnq e = lnk F + 1 n lnc e 6 ( ) e lnq e = lnq max - K DR ε 2 ε = RTln C q e mg g - 1 q max mg g - 1 K L Langmuir L mg - 1 n Freundlich L g - 1 ε polenyi K DR E 7

3 E = 2K DR - 1 / ΔG θ ΔH θ ΔS θ ΔG θ = - RTlnK L 8 lnk L = ΔSθ R - ΔHθ RT R J mol - 1 K - 1 T K K L Langmuir L mg - 1 lnk L 1 /T ΔG θ ΔH θ ΔS θ cm - 1 OH 17 cm cm - 1 OH 1631 cm - 1 C O 2 cm cm cm cm - 1 CH cm cm - 1 OH 1000 cm Fig 1 1 Infrared spectra of tea seed powder 2 2 T = 308 K mg L g L - 1 t q η 2 2 a q 6 g L mg L min min 2 8 g L mg L min 95% 15 min 98% 30 min 99% 2 b 2 3 ph 308 K 8 mg L mg L - 1 ph mg g mg g min ph 7 5

4 % ph % ph mg g % 2 a b Fig 2 Adsorption amount a and removal rate b of methylene blue on tea seed powder as a function of time with different initial methylene blue concentration and tea seed powder dose Fig 3 3 ph Effect of ph value on the adsorption amount and removal rate of methylene blue on tea seed powder 2 4 Langergren Fig 4 4 a b Kinetics equation fitting curve a Pseudo-first order kinetics b Pseudo-second order kinetics

5 a b R 2 = k 2 = g mg - 1 min - 1 q e mg g - 1 q e mg g q t t 1 /2 15 min t 1 /2 = 3 9 min 1 /2 t 1 /2 75 min t 1 /2 = 8 7 min 1 /2 60 mg L mg L - 1 k mg g - 1 min - 1 / Fig 5 Intra-particle diffusion plots for methylene blue adsorption on tea seed powder Fig 6 Pore diffusion plots for methylene blue adsorption on tea seed powder Langmuir Freundlich Dubinin-Radushkevish 5 7 Langmuir Langmuir > Dubinin-Radushkevich > Freundlich Langmuir R 2 > 0 9 K L q max / K 1 q max / mg g - 1 Table 1 Langmuir Freundlich Dubinin-Radushkevish Constants of Langmuir Freundlich and Dubinin-Radushkevish isotherms for methylene q max / mg g - 1 blue adsorption by tea seed powder at different temperatures Langmuir K L / L mg - 1 R 2 Freundlich K F / L g /n R 2 D-R K DR E / kj mol - 1 R

6 ΔG θ ΔH θ ΔS θ lnk L K L Langmuir 1 /T 8 ΔH θ ΔS θ ΔG θ ΔH θ ΔS θ 2 Fig Langmuir Langmuir isotherms for the adsorption of methylene Fig 8 Effect of temperature on the equilibrium constants blue by tea seed powder of methylene adsorption blue by tea seed powder 2 ΔG θ ΔH θ ΔS θ 0 ΔG θ 0-20 kj mol - 1 ΔG θ kj mol - 1 ΔG θ kj mol ΔH θ < 0 ΔH θ 30 kj mol ΔS θ < 0 Table 2 2 Values of thermodynamic parameters for the adsorption of methylene blue on tea seed powder /K K L / L mg - 1 ΔG θ / kj mol - 1 ΔS θ / J mol - 1 K - 1 ΔH θ / kj mol K 8 g L mg L min 99% Langmuir ph mg g mg g - 1 ph ph 4 ΔG θ ΔH θ ΔS θ 0

7 Grégorio C Non-conventional low-cost adsorbents for dye removal A review J Bioresource Technology Keggin Dawson J Mittal A Malviya A Kaur D et al Studies on the adsorption kinetics and isotherms for the removal and recovery of Methyl Orange from wastewaters using waste materials J Journal of Hazardous Materials / Gadd G M Biosorption Critical review of scientific rationale environmental importance and significance for pollution treatment J Journal of Chemical Technology & Biotechnology Forgacs E Cserháti T Oros G Removal of synthetic dyes from wastewaters A review J Environment International Senthilkumaar S Kalaamani P Porkodi K et al Adsorption of dissolved Reactive red dye from aqueous phase onto activated carbon prepared from agricultural waste J Bioresource Technology Wang S Zhu Z H Characterisation and environmental application of an Australian natural zeolite for basic dye removal from aqueous solution J Journal of Hazardous Materials B J J J J J J Qin Qingdong Ma Jun Liu Ke Adsorption of anionic dyes onammonium-functionalized MCM-41 J Journal of Hazardous Materials Haquea E Leea J E Jangb I T et al Adsorptive removal of methyl orange from aqueous solution with metal-organic frameworks porous chromium-benzenedicarboxylates J Journal of Hazardous Materials J B J J J Mechanistic study on adsorption of methylene blue on tea seed powder ZHANG Jia 1 REN Bingxiong 2 WANG Peng 3 WANG Chongchen 1 3* 1 Beijing Climate Change Response Research and Education Center Beijing University of Civil Engineering and Architecture Beijing China 2 Beijing Cycletimes Environment Science & Technology Co Ltd Beijing China 3 Key Laboratory of Urban Storm Water System and Water Environment Beijing University of Civil Engineering and Architecture Beijing China ABSTRACT In order to investigate the dye adsorption properties of tea seed powder methylene blue was chose as the sorbate The data obtained at different temperatures K were fitted with Langmuir Freundlich and Dubinin-Radushkevish models to describe the equilibrium isotherms The kinetics rates were modeled using pseudo-first-order and pseudo-second-order kinetic equations The Gibbs free energy "G θ enthalpy change "H θ and entropy change "S θ were calculated The results revealed that the equilibrium adsorption amount decreased with the increase of temperature The adsorption could be well depicted by the Langmuir adsorption isotherm The Gibbs free energy "G θ enthalpy change "H θ and entropy change "S θ were negative indicating that the adsorption was a spontaneous exothermic and decreasing entropy process The adsorption kinetics followed pseudo-second-order kinetic equation Keywords tea seed powder methylene blue adsorption thermodynamics kinetics

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任秉雄 王崇臣 ENVIRONMENTAL CHEMISTRY. 744 t 50% 10% 20% 1 mg L t S. SHZ-82 Spectrum-100 C 16 H 18 N 3 SCl 3H 2 O

任秉雄王崇臣 ENVIRONMENTAL CHEMISTRY. 744 t 50% 10% 20% 1 mg L t S. SHZ-82 Spectrum-100 C 16 H 18 N 3 SCl 3H 2 O