Removal of Congo Red from Aqueous Solution by Sorption on Organified Rectorite     

Yi Liu  Wenbo Wang  Aiqin Wang 《洁净——土壤、空气、水》2010,38(7):670-677

Batch sorption technique was carried out for the removal of anionic dye Congo red (CR) from aqueous solution using raw rectorite (R‐REC) and organified rectorite (CTA⁺‐REC) modified by cetyltrimethylammonium bromide (CTAB) as adsorbents. The effects of organification degree of CTA⁺‐REC as well as the process parameters including the pH of dye solution, sorption time, and initial dye concentration on adsorption capacity for CR were investigated and the sorption kinetics was also evaluated. The results showed that the sorption behaviors of R‐REC and CTA⁺‐REC for CR followed pseudo‐second‐order kinetic model and the sorption equilibrium data perfectly obeyed the Langmuir isotherm. The thermodynamic parameters including entropy of sorption (ΔS⁰), enthalpy of sorption (ΔH⁰), and Gibbs free energy of sorption (ΔG⁰) were obtained and analyzed. Fourier transform infrared study revealed that a chemisorption process occurred between CR and CTA⁺‐REC. REC modified by cationic surfactants showed the higher adsorption capacities for CR compared to R‐REC and in theory would be used as an efficient and promising adsorbent for the removal of anionic dyes in wastewater treatment.  相似文献   

Adsorption Characteristics of Reactive Black 5 from Aqueous Solution onto Chitosan     

Tapan K. Saha  Nikhil C. Bhoumik  Subarna Karmaker  Mahmooda G. Ahmed  Hideki Ichikawa  Yoshinobu Fukumori 《洁净——土壤、空气、水》2011,39(10):984-993

Adsorption of reactive black 5 (RB5) from aqueous solution onto chitosan was investigated in a batch system. The effects of solution pH, initial dye concentration, and temperature were studied. Adsorption data obtained from different batch experiments were modeled using both pseudo first‐ and second‐order kinetic equations. The equilibrium adsorption data were fitted to the Freundlich, Tempkin, and Langmuir isotherms over a dye concentration range of 45–100 µmol/L. The best results were achieved with the pseudo second‐order kinetic and Langmuir isotherm equilibrium models, respectively. The equilibrium adsorption capacity (q_e) was increased with increasing the initial dye concentration and solution temperature, and decreasing solution pH. The chitosan flakes for the adsorption of the dye was regenerated efficiently through the alkaline solution and was then reused for dye removal. The activation energy (E_a) of sorption kinetics was estimated to be 13.88 kJ/mol. Thermodynamic parameters such as changes in free energy (ΔG), enthalpy (ΔH), and entropy (ΔS) were evaluated by applying the van't Hoff equation. The thermodynamics of reactive dye adsorption by chitosan indicates its spontaneous and endothermic nature.  相似文献   

Assessment of the Biosorption Characteristics of a Spent Cottonseed Husk Substrate for the Decolorization of Methylene Blue     

Qi Zhou  Wenqi Gong  Dongjiang Yang  Chuanxin Xie  Yubiao Li  Xiafang Liu  Cuiping Bai  Rui Wang 《洁净——土壤、空气、水》2011,39(12):1087-1094

This study concentrates on the possible application of the spent cottonseed husk substrate (SCHS), an agricultural waste used after the cultivation of white rot fungus Flammulina velutipes, to adsorb methylene blue (MB) from aqueous solutions. Batch studies were carried out with variable initial solution pH, adsorbent amount, reaction time, temperature, and initial MB concentration. MB uptake was favorable at pH ranging from 4.0 to 12.0, and the equilibrium adsorption capacity of 143.5 mg g^?1 can be reached promptly within about 240 min. The combination analysis of FTIR and BET techniques revealed that the massive functional groups on the biosorbent surface, such as hydroxyl and carboxyl, were responsible for the biosorption of MB. It was found that adsorption data matched the pseudo‐second order kinetic and Langmuir isotherm models. Thermodynamic parameters of free energy (ΔG°), enthalpy (ΔH°), and entropy (ΔS°), obtained from biosorption MB ranging from 293 to 313 K, showed that the sorption experiment was a spontaneous and endothermic process. The study highlighted a new pathway to develop a new potential utilization of SCHS as a low‐cost sorbent for the removal of MB pollutants from wastewater.  相似文献   

Removal of Heavy Metals from Synthetic Mixture as well as Pharmaceutical Sample Via Cation Exchange Resin Modified with Rhodamine B: Its Thermodynamic and Kinetic Studies     

Syed A. Nabi  Mohammad Shahadat  Abid H. Shalla  Amjad M. T. Khan 《洁净——土壤、空气、水》2011,39(12):1120-1128

A new sorbent was prepared by loading rhodamine B on Amberlite IR‐120. Various physico‐chemical parameters such as effects of adsorbate concentration, contact time, pH, and temperature on the sorption of the dye have been studied. Thermodynamic parameters (ΔH° and ΔS°) were also evaluated for the sorption of dye. Kinetic studies revealed that the sorption of the dye was best fit for pseudo‐second‐order kinetic. The metal ion uptake in different solvent systems has been explored through column studies. On the basis of distribution coefficient (K_d), some heavy metal ions of analytical interest from binary mixtures have been separated. The limit of detection (LOD) for the Ni²⁺ and Fe³⁺ metal ions was 0.81 and 0.60 µg L^?1, and the limit of quantification (LOQ) was found to be 2.72 and 2.0 µg L^?1. This sorbent has also been successfully applied in the analysis of multivitamin formulation. The applicability of the modified resin in the separation of heavy metals constituting real and synthetic samples has been explored.  相似文献   

The Seashell Wastes as Biosorbent for Reactive Dye Removal from Textile Effluents     

Daniela Suteu  Doina Bilba  Magdalena Aflori  Florica Doroftei  Gabriela Lisa  Marinela Badeanu  Teodor Malutan 《洁净——土壤、空气、水》2012,40(2):198-205

This study investigates structural and adsorption properties of the powdered waste shells of Rapana gastropod and their use as a new cheap adsorbent to remove reactive dye Brilliant Red HE‐3B from aqueous solutions under batch conditions. For the powder shells characterization, solubility tests in acidic solutions and X‐ray diffraction (XRD), scanning electron microscopy (SEM), energy‐dispersive X‐ray spectroscopy (EDX), Fourier transform IR spectroscopy (FT‐IR) and thermogravimetric analyses were performed. The results revealed that the adsorbent surface is heterogeneous consisting mainly from calcium carbonate layers (either calcite or aragonite) and a small amount of organic macromolecules (proteins and polysaccharides). The dye adsorptive potential of gastropod shells powder was evaluated as function of initial solution pH (1–5), adsorbent dose (6–40 g L^?1), dye concentration (50–300 mg L^?1), temperature (5–60°C), and contact time (0–24 h). It was observed that the maximum values of dye percentage removal were obtained at the initial pH of solution 1.2, shells dose of 40 g L^?1, dye initial concentration of 50–50 mg L^?1 and higher temperatures; the equilibrium time decreases with increasing of dye concentration. It is proved that the waste seashell powder can be used as low cost bioinorganic adsorbent for dyes removal from textile wastewaters.  相似文献   

Synthesis and Characterization of Poly(2‐hydroxyethylmethacrylate‐hydroxyapatite) a Novel Composite for the Removal of Lead(II) from Aqueous Solutions     

Recep Akkaya 《洁净——土壤、空气、水》2012,40(11):1257-1264

In the present study, a novel adsorbent, poly (2‐hydroxyethylmethacrylate‐hydroxyapatite) [P(HEMA‐Hap)], was prepared and characterized. The synthesis was achieved by means of free‐radical polymerization and a number of structural characterization methods, including FT‐IR, XRD, TGA, SEM, BET‐porosity, and swelling tests. Pb²⁺ adsorption was performed using a series of pH, time, and temperature ranges. The reusability of the composite was also tested. The results obtained indicated that the novel adsorbent is able to bind Pb²⁺ ions with strong chemical affinity. The adsorption results were fitted to the classic Langmuir, Freundlich, and Dubinin–Radushkevich (D–R) sorption models. Thermodynamic parameters obtained demonstrated that the sorption process was spontaneous (ΔG < 0), endothermic (ΔH > 0), as expected. The process was also consistent with the pseudo‐second‐order model, and chemical adsorption was determined to be the rate‐controlling step. It was also shown that the composite could be used for five consecutive adsorption processes.  相似文献   

Adsorption of Thallium(I) Ions Using Eucalyptus Leaves Powder     

Hossein Dashti Khavidaki  Hossein Aghaie 《洁净——土壤、空气、水》2013,41(7):673-679

Using batch method, the adsorption of thallium(I) ions from aqueous solutions on eucalyptus leaves powder, as a low cost adsorbent, was studied. The effect of various modification of considered adsorbent on the adsorption percentage of Tl(I) is an important feature of this study. The results showed that the unmodified and acidic modified adsorbent are the poor adsorbents for the Tl(I) ions while basic modified adsorbent is a suitable adsorbent. Also, the effect of some experimental conditions such as solution initial pH, agitation speed, contact time, sorbent dosage, temperature, particle size, and thallium initial concentration was studied. The results showed that the adsorption percentage depends on the conditions and the process is strongly pH‐dependent. The satisfactory adsorption percentage of Tl(I) ions, 81.5%, obtained at 25 ± 1°C. The equilibrium data agreed fairly better with Langmuir isotherm than Freundlich and Temkin models. The value of q_m that was obtained by extrapolation method is 80.65 mg g^?1. Separation factor values, R_L, showed that eucalyptus leaves powder is favorable for the sorption of Tl(I). The negative values of ΔH⁰ and ΔS⁰ showed that the Tl(I) sorption is an exothermic process and along with decrease of randomness at the solid–solution interface during sorption, respectively.  相似文献   

Adsorption Characteristics of Rhodamine B from Aqueous Solution onto Baryte     

Govindasamy Vijayakumar  Chang Kyoo Yoo  Kuppana Gounder P. Elango  Mahendiradas Dharmendirakumar 《洁净——土壤、空气、水》2010,38(2):202-209

Batch sorption experiments were carried out for the adsorption of the basic dye Rhodamine B from aqueous solution using baryte as the adsorbent. The effect of adsorbent dosage, temperature, initial dye concentration and pH were studied. Adsorption data were modeled using first and second order kinetic equations and the intra particle diffusion model. Kinetic studies showed that the adsorption process followed second order rate kinetics with an average rate constant of 0.05458 g mg^–1 min^–1. Dye adsorption equilibrium was attained rapidly after 30 min of contact time. The equilibrium data was fitted to the Langmuir, Freundlich and Tempkin isotherms over a dye concentration range of 50–250 mg/L. The adsorption thermodynamic parameters showed that adsorption was an exothermic, spontaneous and less ordered arrangement process. The adsorbent, baryte, was characterized by Fourier transform infrared spectroscopy and scanning electron microscopy. The results showed that baryte has good potential for the removal of Rhodamine B from dilute aqueous solution.  相似文献   

Adsorption of Pb(II) Ions from Aqueous Solutions by Date Bead Carbon Activated with ZnCl2     

Mohammed Danish  Rokiah Hashim  Mohd Rafatullah  Othman Sulaiman  Anees Ahmad  Govind 《洁净——土壤、空气、水》2011,39(4):392-399

This study reports on the adsorption characteristics of Pb(II) ions from aqueous solutions using ZnCl₂‐activated date (Phoenix dactylifera) bead (ADB) carbon with respect to change in adsorbent dosage, initial pH, contact time, initial concentration, and temperature of the solution. Kinetic studies of the data showed that the adsorption follows the pseudo‐second‐order kinetic model. Thermodynamic parameters, enthalpy change (ΔH° = 55.11 kJ/mol), entropy change (ΔS° = ? 0.193 kJ/mol/K), and Gibbs free energy change (ΔG°) were also calculated for the uptake of Pb(II) ions. These parameters show that adsorption on the surface of ADB was feasible, spontaneous in nature, and endothermic between temperatures of 298.2 and 318.2 K. The equilibrium data better fitted the Langmuir and Freundlich isotherm models than the D–R adsorption isotherm model for studying the adsorption behavior of Pb(II) onto the ADB carbon. It could be observed that the maximum adsorption capacity of ADB was 76.92 mg/g at 318.2 K and pH 6.5.  相似文献   

Malachite Green Removal from Aqueous Solution by the Peel of Cucumis sativa Fruit     

Thirumalisamy Santhi  Subbian Manonmani 《洁净——土壤、空气、水》2011,39(2):162-170

This study investigates the potential use of activated carbon prepared from the peel of Cucumis sativa fruit for the removal of malachite green (MG) dye from simulated wastewater. The effects of different system variables, adsorbent dosage, initial dye concentration, pH, and contact time were investigated and optimal experimental conditions were ascertained. The results showed that when the amount of the adsorbent increased, the percentage of dye removal increased accordingly. Optimum pH value for dye adsorption was 6.0. Maximum dye was sequestered within 50 min of the start of every experiment. The adsorption of MG followed the pseudo‐second‐order rate equation and fits the Langmuir, Freundlich, Dubinin–Radushkevich (D–R), and Tempkin equations well. The maximum removal of MG was obtained at pH 6 as 99.86% for adsorbent dose of 1 g/50 mL and 25 mg L^?1 initial dye concentration at room temperature. Activated carbon developed from the peel of C. sativa fruit can be an attractive option for dye removal from diluted industrial effluents since test reaction made on simulated dyeing wastewater showed better removal percentage of MG.  相似文献   

Base Treated Cogon Grass (Imperata cylindrica) as an Adsorbent for the Removal of Ni(II): Kinetic,Isothermal and Fixed‐bed Column Studies     

Megat Ahmad Kamal Megat Hanafiah  Haslizaidi Zakaria  Wan Saime Wan Ngah 《洁净——土壤、空气、水》2010,38(3):248-256

The adsorption of Ni(II) from aqueous solutions using base treated cogon grass or Imperata cylindrica (NHIC) was performed under batch and column modes. Batch experiments were conducted to determine the factors affecting adsorption such as pH, adsorbent dosage, initial nickel concentration, contact time and temperature. The fixed‐bed column experiment was performed to determine the practical applicability of NHIC and to obtain the breakthrough curve. Adsorption was fast as equilibrium was achieved within 60 min, and was best described by the pseudo second order model. According to the Langmuir model, a maximum adsorption capacity of 6.96 mg/g was observed at pH 5 and at a temperature of 313 K. Thermodynamic parameters such as ΔG⁰, ΔH⁰ and ΔS⁰ were calculated, and indicated that adsorption was a spontaneous and endothermic process. The mechanistic pathway of Ni(II) uptake was examined by Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM) and energy dispersive X‐ray (EDX) spectroscopy. The Thomas and Yoon‐Nelson models were used to analyze the fixed‐bed column data.  相似文献   

Kinetics,Mechanistic and Thermodynamics of Zn(II) Ion Sorption: A Modeling Approach     

Vishal Mishra  Chandrajit Balomajumder  Vijay Kumar Agarwal 《洁净——土壤、空气、水》2012,40(7):718-727

Biosorption potential of Cedrus deodara sawdust (CDS) in terms of sorption of Zn(II) ion across liquid phase has been evaluated in the present investigation. The surface of the CDS biomass before the sorption of Zn(II) ions seemed to be more porous, non‐crystalline and heterogeneous. The maximum uptake capacity of CDS was 97.39 mg g^?1. Sorption of Zn(II) ion on the surface of CDS sawdust was maximum at pH 5, temperature 45°C, initial concentration of Zn(II) ion 100 mg L^?1, biomass dose 1 g L^?1, contact time 150 min, and agitation rate 160 rpm. Pseudo second‐order kinetics with the highest linear regression coefficient (R² = 0.99), and lowest values of error functions, i.e., chi (χ²) and sum of square errors (SSE) against pseudo first‐order rate kinetics showed that the sorption of Zn(II) ion on the surface of CDS was mediated by chemosoprtive forces of attraction rather than physical adsorption. Mechanistically, relatively higher proportion of sorption of Zn(II) ion in early phase of contact time was profoundly explained by Bangham's equation and film diffusivity (D^f). Intraparticle or pore diffusion (D_p) of Zn(II) ion inside the pores of CDS was rate limiting step at the later stage of contact time. Furthermore, the thermodynamic study on sorption of metal ion delineated the fact that the Zn(II) sorption on the surface of CDS was spontaneous, endothermic together with increased entropy at solid liquid interface.  相似文献   

Removal of Selenium by Adsorption onto Granular Activated Carbon (GAC) and Powdered Activated Carbon (PAC)     

Kailas L. Wasewar  Basheshwar Prasad  Sekhararao Gulipalli 《洁净——土壤、空气、水》2009,37(11):872-883

The present work involves the study of Se(IV) adsorption onto granular activated carbon (GAC) and powdered activated carbon (PAC). The adsorbents are coated with ferric chloride solution for the effective removal of selenium. The physico-chemical characterization of the adsorbents is carried out using standard methods, e. g., proximate analysis, scanning electron microscopy (SEM), fourier transform infrared spectroscopy (FTIR), thermo-gravimetric (TGA) and differential thermal analysis (DTA), etc. The FTIR spectra of the GAC and PAC indicate the presence of various types of functional groups, e. g., free and hydrogen bonded OH groups, silanol groups (Si-OH), alkenes, and CO group stretching from aldehydes and ketones on the surface of adsorbents. Batch experiments are carried out to determine the effect of various factors such as adsorbent dose (w), initial pH, contact time (t), and temperature (T) on the adsorption process. The optimum GAC and PAC dosage is found to be 10 g/L and 8 g/L, respectively, for Se(IV) removal with C₀ = 100 mg/L. The percent removal of Se(IV) increases with increasing adsorbent concentration, while removal per unit weight of adsorbent increases with decreasing adsorbent concentration. Se(IV) adsorption onto both the GAC and PAC adsorbents is high at low pH values, and decreases with increased initial pH. The results obtained are analyzed by various kinetic models. The parameters of pseudo-first order, pseudo-second order kinetics, and Weber-Morris intra particle kinetics are determined. It is seen that the sorption kinetics of Se(IV) onto GAC and PAC can be best represented by the pseudo-second order kinetic model.  相似文献   

The sorption behavior of DDT onto sediment in the presence of surfactant cetyltrimethylammonium bromide     

Cao X  Han H  Yang G  Gong X  Jing J 《Marine pollution bulletin》2011,62(11):2370-2376

The sorption behavior of p,p′- and o,p′-dichlorodiphenyltrichloroethane (DDT) in the presence of a cationic surfactant cetyltrimethylammonium bromide (CTAB) on sediment was studied. Batch experiments were carried out to investigate the kinetics and thermodynamics of the process. The kinetic behavior of these three chemicals on sediment was described by pseudo-second-order kinetic equations, and the isotherms followed the Freundlich model well. The presence of CTAB was able to remarkably accelerate and enhance the sorption of DDT, whereas DDT showed no effect on the sorption of CTAB in our considered concentration ranges. The thermodynamic parameters, such as standard enthalpy change (ΔH⁰), standard entropy change (ΔS⁰) and standard Gibbs free energy change (ΔG⁰) showed that the sorption process of p,p′- and o,p′-DDT was physical, spontaneous and exothermic, and the randomness at the solid-liquid interface increased during the process. In the presence of CTAB, the sorption of DDT showed significantly negative ΔG⁰ and ΔH⁰ values.  相似文献   

Parameter Optimization of Activated Carbon Production from Agave sisalana and Punica granatum Peel: Adsorbents for C.I. Reactive Orange 4 Removal from Aqueous Solution     

Thambiannan Senthilkumar  Rajendran Raghuraman  Lima Rose Miranda 《洁净——土壤、空气、水》2013,41(8):797-807

In the present study, activated carbons were prepared from sisal fiber (Agave sisalana sp.) and pomegranate peel (Punica granatum sp.) using phosphoric acid as the activating agent. Both sisal fiber activated carbon (SFAC) and pomegranate peel activated carbon (PPAC) were characterized using methylene blue number, iodine number, BET surface area, SEM, and FTIR. The BET surface area of the SFAC and PPAC were 885 and 686 m²/g, respectively. The adsorption studies using C.I. Reactive Orange 4 dye on the SFAC and PPAC were carried out. The effects of time, initial adsorbate concentration, pH, and temperature on the adsorption were studied. The isotherm studies were carried and it was found that the Langmuir and Freundlich isotherms fit well for the adsorption of RO 4 on SFAC, while adsorption of RO 4 on PPAC is better represented by the Langmuir and Temkin isotherms. Adsorption kinetics of adsorption was determined using pseudo first order, pseudo second order, Elovich and intraparticle diffusion models and it was found that the adsorption process follows pseudo second order model. Thermodynamics parameters such as changes in free energy (ΔG), enthalpy (ΔH), and entropy (ΔS) were determined by using van't Hoff equation. The positive ΔH value indicates that RO 4 dye adsorption on SFAC and PPAC is endothermic in nature.  相似文献   

Modeling the Removal of Reactive Red 120 on Pistachio Husk     

Abuzer Çelekli  Mehmet Yavuzatmaca  Hüseyin Bozkurt 《洁净——土壤、空气、水》2010,38(2):173-180

In this study, the adsorption of reactive red 120 (RR 120) on pistachio husk, and the modeling of the adsorption was investigated. Characterization of the pistachio husk was confirmed by Fourier transform infrared spectroscopy. The pH_zpc of pistachio husk was found to be pH 8.5. Increasing the initial pH value decreased (p < 0.01) the amount of dye adsorbed. However, increasing the initial dye concentration from 50 to 900 mg/L at pH 1 increased (p < 0.01) the equilibrium dye uptake from 20.83 to 182.10 mg/g. Results indicated that this adsorbent had great potential for the removal of RR 120 dye. The logistic model was found to be the most suitable of the kinetic and equilibrium models tested to describe the adsorption of the dye. The parameters determined from the logistic model were well correlated with the initial dye concentration, and were seen to increase with the increasing initial dye concentration, but this was not observed from pseudo‐second order kinetics.  相似文献   

Adsorption of Amaranth Dye onto Alumina Reinforced Polystyrene     

Rais Ahmad  Rajeev Kumar 《洁净——土壤、空气、水》2011,39(1):74-82

  相似文献   

Adsorption Performance and Mechanism in Binding of Azo Dye by Raw Bentonite     

Erdal Eren 《洁净——土壤、空气、水》2010,38(8):758-763

The adsorption behavior of methyl orange (MO) from aqueous solution onto raw bentonite (RB) sample was investigated as a function of parameters such as pH, inorganic anion, contact time, and temperature. The Langmuir and Freundlich adsorption models were applied to describe the equilibrium isotherms. Langmuir adsorption capacity was found to be 34.34 mg/g at pH 4.0. The pseudo‐first‐order, pseudo‐second‐order kinetic, and the intra‐particle diffusion models were used to describe the kinetic data. The values of the energy (E_a), enthalpy (ΔH^≠), and entropy of activation (ΔS^≠) were calculated as 38.62 kJ/mol, 36.04 kJ/mol, and ?150.05 J/mol K, respectively, at pH 4.0.  相似文献   

Adsorptive Removal of Acid Blue 15: Equilibrium and Kinetic Study     

N. Thinakaran  P. Baskaralingam  K. V. Thiruvengada Ravi  P. Panneerselvam  Subramanian Sivanesan 《洁净——土壤、空气、水》2008,36(9):798-804

Activated carbons prepared from sunflower seed hull have been used as adsorbents for the removal of acid blue 15 (AB‐15) from aqueous solution. Batch adsorption techniques were performed to evaluate the influences of various experimental parameters, e. g., temperature, adsorbent dosage, pH, initial dye concentration and contact time on the adsorption process. The optimum conditions for AB‐15 removal were found to be pH = 3, adsorbent dosage = 3 g/L and equilibrium time = 4 h at 30°C. The adsorption of AB‐15 onto the adsorbent was found to increase with increasing dosage. It was found from experimental results that the Langmuir isotherm fits the data better than the Freundlich and Temkin isotherms. The maximum adsorption capacity, Q_m (at 30°C) was calculated for SF1, SF2, and SF3 as 75, 125 and 110 mg g^–1 of adsorbent, respectively. It was found that the adsorption follows pseudo‐second order kinetics. The thermodynamic parameters such as ΔG°, ΔH°, and ΔS° were also evaluated. The activated carbons prepared were characterized by FT‐IR, SEM and BET analysis.  相似文献   

Sorption-desorption kinetics and toxic cell concentration in marine phytoplankton microalgae exposed to Linear Alkylbenzene Sulfonate     

Renaud F  Oberhänsli F  Teyssié JL  Miramand P  Temara A  Warnau M 《Marine pollution bulletin》2011,62(5):942-947

Linear Alkylbenzene Sulfonates (LAS) are ubiquitous surfactants. Traces can be found in coastal environments. Sorption and toxicity of C₁₂-LAS congeners were studied in controlled conditions (2-3500 μg C₁₂LAS/L) in five marine phytoplanktonic species, using standardized methods. IC₅₀ values ranged from 0.5 to 2 mg LAS/L. Sorption of ¹⁴C₁₂-6 LAS isomer was measured at environmentally relevant trace levels (4 μg/L) using liquid scintillation counting. Steady-state sorption on algae was reached within 5 h in the order dinoflagellate > diatoms > green algae. The sorption data, fitted a L-type Freundlich isotherm, indicating saturation. Desorption was rapid but a low LAS fraction was still sorbed after 24 h. Toxic cell concentration was 0.38 ± 0.09 mg/g for the studied species. LAS toxicity results from sorption on biological membranes leading to non-specific disturbance of algal growth. Results indicate that LAS concentrations in coastal environments do not represent a risk for these organisms.  相似文献