[Adsorption of BS-18 Amphoterically Modified Bentonite to Tetracycline and Norfloxacin Combined Pollutants].

Antibiotic pollution in the environment has become a hot topic. The amphoteric surfactant octadecyl dimethyl betaine (BS-18) was adopted to modify bentonite to investigate the effects and mechanisms of the composite adsorption of different types of antibiotics. Under the different modification ratios, temperatures, pH values, and ionic strength conditions, the adsorption of tetracycline (TC) and norfloxacin (NOR) by bentonite was studied under single and compound conditions, and the adsorption mechanism was analyzed and discussed in combination with the surface properties of amphoterically modified bentonite. The results showed that compared with those of CK, the CEC and specific surface area of the soil samples modified by BS-18 decreased, whereas the total carbon and total nitrogen contents increased. The adsorption order of BS-18 amphoterically modified bentonite to TC was CK > 100BS > 25BS > 50BS, which was in accordance with the Langmuir model; the adsorption order of NOR was 25BS > 50BS > CK > 100BS, which was consistent with the Henry model. The adsorption capacity of TC and NOR in the TC and NOR composite system was higher than that in the single system. With the increase in temperature, the adsorption of amphoterically modified bentonite to TC showed a positive warming effect, whereas the adsorption of NOR declined as the temperature increased. When the ionic strength increased from 0.001 mol·L-1 to 0.500 mol·L-1, the adsorption of TC and NOR on each soil sample was inhibited. The pH of the solution can affect the existing forms of TC and NOR, and the adsorption capacity showed different trends as the pH increased. The adsorption of TC by BS-18-modified bentonite was mainly caused by electric charge attraction, whereas the adsorption of NOR was mainly caused by the combination of electric charge attraction and the hydrophobic effect. The different values of the octanol/water partition coefficient and the difference in structure resulted in different adsorption modes. In the TC and NOR composite system, a TC+NOR mixture was formed to promote the adsorption of soil samples.

[Adsorption and Interaction of Cu2+ and Pb2+ on BS-12 Amphoteric Modified Bentonites].

Amphoteric modification can simultaneously improve the adsorption of organic pollutants and heavy metals on clay minerals. Study of the adsorption and interaction of multiple heavy metals on amphoteric modified soils is therefore of practical significance. Here, bentonite-(CK) and 150BS-12-modified bentonites (150BS-12) were characterized both before and after metal ion adsorption using Fourier-transform infrared spectroscopy (FTIR). The equilibrium adsorption characteristics and differences of Cu2+ and Pb2+ in single and binary systems were studied by batch methods. The interaction mechanism of the metals on modified bentonites is also discussed. The results showed that the adsorption capacity of Cu2+ and Pb2+ in single and binary systems was ranked, in descending order, as 150BS-12 > 100BS-12 > 50BS-12 > CK, and that the adsorption isotherm could be described by the Langmuir and Freundlich equations. Although the modification of BS-12 was more beneficial for the adsorption of Cu2+, the adsorption capacity and selectivity coefficient of Pb2+ on BS-12-modified bentonites were larger than for Cu2+. Cu2+ and Pb2+ had a mutually antagonistic effect on each other; modification with BS-12 enhanced the effect of Cu2+ on Pb2+ and weakened the effect of Pb2+ on Cu2+, which was always stronger than the effect of Cu2+ on Pb2+. Increases in temperature and pH, and a reduction in ionic strength, can increase the adsorption of Cu2+ and Pb2+; however, the influence of these factors varied between the two metals, which also affected the interaction between the metals.

[Comparison of Amphoteric-Cationic and Amphoteric-Anionic Modified Magnetic Bentonites:Characterization and Sorption Capacity of Phenol].

Magnetic bentonite is modified by an amphoteric surfactant (dodecyl dimethyl betaine, BS-12), then modified by a cationic surfactant (Cetyl Trimethyl Ammonium Bromide, CTMAB) and anionic surfactant (Sodium lauryl sulfonate, SDS). Amphoteric-cationic modified magnetic bentonite (BS-CT-MBT) and amphoteric-anionic modified magnetic bentonite (BS-SDS-MBT) are obtained. Structural identification of the samples were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), thermogravimetric analyses (TG), Fourier transform infrared spectra (FTIR), and vibrating sample magnetometer (VSM). The carbon-nitrogen content, specific surface area, and pore volume were also evaluated. Batch isotherm studies were conducted to evaluate the sorption of phenol. The results show that BS-CT-MBT and BS-SDS-MBT can be separated by magnetic separation. The carbon content-nitrogen content and content of surfactants of the BS-CT-MBT increase, while surface area and pore volume decrease compared to those of BS-MBT. Compared with BS-MBT, the carbon-nitrogen content, content of surfactants, and pore volume of BS-SDS-MBT are decreasing and surface area is increasing. The desorption rate of the surfactants is less than 9% at pH 6.0 and in 0.1 mol·L-1 NaCl solution. The Henry equation is the optimal description for the phenol sorption isotherms, implying a partitioning sorption process. The amount of phenol sorption follows the order:BS-CT-MBT > BS-MBT > BS-SDS-MBT > BT > MBT, which significantly correlates with the variation of the content of surfactant. Amphoteric magnetic bentonites modified by CTMAB have better absorption performance for phenol than those modified by SDS.

[Application of Amphoteric-Cationic Combined Modification on Phenol Adsorption of Yellow Brown Soil].

Based on the best modification ration of adsorption of phenol on montmorillonite modified by a mixture of amphoteric modifier, dodecyl dimethyl betaine(BS-12), and cationic modifier, hexadecyltrimethyl ammonium bromide(CTMAB),an experiment was designed to prepare two series of amphoteric-cationic modified soils by two yellow brown soils with montmorillonite contents of 43% and 6%,respectively. The adsorption properties of phenol were studied, and the adsorption influence at different temperature, pH and ionic strength was also analyzed and moreover, the adsorption differences between co-modified montmorillonite and yellow brown soils and between two co-modified yellow brown soils were discussed by comparing with co-modified montmorillonite. The results showed that adsorption of yellow brown soils as well as co-modified montmorillonite on phenol increased with combined modification, adsorption capacity was in order of 215BS+215CT(215%BS-12+215%CTMAB) > 215CT(215%CTMAB) > 215BS(215%BS-12) > CK1(unmodified soil containing montmorillonite content of 43%),33BS+33CT(33%BS-12+33%CTMAB) > 33CT(33%CTMAB) > 33BS(33%BS-12) > CK2(unmodified soil with montmorillonite content of 6%) at 30℃.Henry model described the adsorption of phenol very well. The phenol adsorption of modified yellow brown soils decreased with increasing temperature and pH, but increased with increasing ionic strength at low concentration ranges as well as modified montmorillonite. The basic reason for adsorption difference between co-modified montmorillonite and yellow brown soils and between two co-modified yellow brown soils was Cation Exchange Capacity(CEC).

[Effect of Adding Compound Adsorbent on Phenanthrene and Cr(â ¥) Absorption by Lou Soil].

To study the effect of the addition of compound adsorbent on the phenanthrene and Cr(Ⅵ) adsorption of Lou soil, biochar (made from corn stover) and B200B (Bentonite modified by BS-12, dodecyl dimethyl betaine with modified ratio of 200% CEC of Bentonite) were mixed at mass ratios of 1:2, 1:1 and 2:1 as the compound adsorbents (CS1:2, CS1:1 and CS2:1). Different amounts (2%, 5% and 10%) of these three compound adsorbents were added into Lou soil. Batch method was used to analyze the phenanthrene and Cr(Ⅵ) adsorption isotherms of different Lou samples, and compare the effect of environmental conditions such as pH value and temperature on the phenanthrene and Cr(Ⅵ) adsorption. The results indicated: ① Adsorption amounts of Cr(Ⅵ) on different Lou samples were 3.02 to 13.61 times higher than CK (original Lou soil). Under the same adding conditions (amount), Cr(Ⅵ) adsorption showed the order of CS2:1 Lou > CS1:1 Lou > CS1:2 Lou > CK. Cr(Ⅵ) adsorption was a spontaneous process with decreased enthalpy (except CS1:2) and increased entropy. Adsorption amounts of phenanthrene on different Lou samples were 3.87 to 13.00 times higher than CK. Phenanthrene adsorption presented the ranking of CS1:2 Lou > CS2:1 Lou > CS1:1 Lou > CK at the adding amounts of 2% and 5%, while showed the order of CS1:2 Lou > CS1:1 Lou > CS2:1 Lou > CK when 10% of the compound adsorbent was added. The adsorption was also a spontaneous process with decreased enthalpy and increased entropy. ② When the temperature was 10-30℃, the adsorption amount of Cr(Ⅵ) increased by 5.84%, 4.63% and 8.22% on CK, CS1:1 and CS2:1 Lou soils, and reduced by 2.70% on CS1:2 Lou soils. Adsorption amount of phenanthrene increased by 1.69% of CK and reduced by 10.55%, 4.36% and 12.81% of CS2:1, CS1:1 and CS1:2 Lou soils respectively. ③ When the pH was 4-10, the Cr(Ⅵ) adsorption had no significant change for CK, while those for CS1:2, CS1:1 and CS2:1 Lou soils all reduced. Phenanthrene adsorption of CK, CS1:2 and CS1:1 Lou soils was all highest at pH=4, and phenanthrene adsorption of CS2:1 Lou was highest at pH=7.④ The higher the ratio of B200B in compound adsorbent, the better the phenanthrene adsorption was. The higher the ratio of biochar in compound adsorbent, the better the Cr(Ⅵ) adsorption was.

[Leaching Remediation of Copper and Lead Contaminated Lou Soil by Saponin Under Different Conditions].

In order to investigate the leaching remediation effect of the eco-friendly biosurfactant saponin for Cu and Pb in contaminated Lou soil, batch tests method was used to study the leaching effect of saponin solution on single Cu, Pb contaminated Lou soil and mixed Cu and Pb contaminated Lou soil under different conditions such as reaction time, mass concentration of saponin, pH, concentration of background electrolyte and leaching times. The results showed that the maximum leaching removal effect of Cu and Pb in contaminated Lou soil was achieved by complexation of the heavy metals with saponin micelle, when the mass concentration of saponin solution was 50 g x L(-1), pH was 5.0, the reaction time was 240 min, and there was no background electrolyte. In single and mixed contaminated Lou soil, the leaching percentages of Cu were 29.02% and 25.09% after a single leaching with 50 g x L(-1) saponin under optimal condition, while the single leaching percentages of Pb were 31.56% and 28.03%, respectively. The result indicated the removal efficiency of Pb was more significant than that of Cu. After 4 times of leaching, the cumulative leaching percentages of Cu reached 58.92% and 53.11%, while the cumulative leaching percentages of Pb reached 77.69% and 65.32% for single and mixed contaminated Lou soil, respectively. The fractionation results of heavy metals in soil before and after a single leaching showed that the contents of adsorbed and exchangeable Cu and Pb increased in the contaminated soil, while the carbonate-bound, organic bound and sulfide residual Cu and Pb in the contaminated Lou soil could be effectively removed by saponin.

[Effect of SDS on the adsorption of Cd2+ onto amphoteric modified bentonites].

Under different modified ratios, temperatures, pH and ionic strengths, the effect of sodium dodecyl sulfonate (SDS) on the adsorption of Cd2+ onto bentonites which modified with amphoteric modifier dodecyl dimethyl betaine (BS-12) was studied by batch experiments, and the adsorption mechanism was also discussed. Results showed that the adsorption of Cd2+ on amphoteric bentonites can be enhanced significantly by SDS combined modification, Cd2+ adsorption decreases in the order: BS + 150SDS (BS-12 + 150% SDS) > BS + 100SDS (BS-12 + 100% SDS) > BS +50SDS(BS-12 + 50% SDS) > BS + 25SDS (BS-12 + 25% SDS) > BS (BS-12) > CK (unmodified soil). The adsorption isotherm can be described by the Langmuir equation. The change of temperature effect from positive on CK and amphoteric bentonites to negative on BS + 150SDS bentonites is observed with an increase of SDS modified ratio. The pH has little influence on Cd2+ adsorption on bentonites. The adsorption of Cd2+ on bentonites decreases with ionic strength rise, but the effect of ionic strength can be reduced with an increase of SDS modified ratio also. The adsorption thermodynamic parameters demonstrated that the adsorption of Cd2+ on modified bentonites was spontaneously controlled by entropy increment. When the SDS modified ratio is lower than 100% CEC, the adsorption of Cd2+ on modified bentonites is a process with characteristics of both enthalpy increment and entropy increment, while the SDS modified ratio is equal to or higher than 100% CEC, the adsorption of Cd2+ on modified bentonites becomes a process of enthalpy decrement and entropy increment.

[Adsorption of Cd2+ ions in aqueous by diamine-modified ordered mesoporous SBA-15 particles].

Highly ordered channel structure SBA-15 was widely concerned as new adsorbents in environmental protection, in order to increase its heavy metal ions adsorption ability from aqueous solution, the diamine -modified porous silicate SBA-15 was synthesized by a hydrothermal grafting method and characterized by TEM, X-ray diffraction, FTIR and N2 adsorption-desorption. The SBA-15 and modified SBA-15 samples were used as sorbents to adsorb Cd(II) ions from aqueous solution. The effect of experimental parameters, such as pH, contact time, sorbent dosage and temperature were examined, and the maximum adsorption amount was also calculated. The results showed that under same conditions, the Cd(II) removal rate was higher for 2N-SBA-15 than that of the unmodified SBA-15. The adsorption process was controlled by system pH. The highest removal rate could reached about 95% after pH was higher than 4. Adsorption equilibrium was reached within 30 minutes,and more than 95% Cd2+ was adsorbed when 7.5-20 mg sorbent was added into 100 mL solution contained 25 mg x L(-1) Cd2+. The adsorption capacity increased from 94.73% to 98.22% with temperature increased from 25 degrees C to 35 degrees C. The Langmuir model can be used to describe adsorption isotherms. The adsorption capacity of Cd2+ was 0.9 mmol x g(-1) which is comparable to the adsorption capacity of various adsorbents reported in the literature, and 0.1 mol x L(-1) HCl could remove nearly 93% Cd2+ from 2N-SBA-15 particles. Based on the thermodynamic, pH, XPS and Zeta potential analysis results in this study, it could be concluded that the adsorption process was an endothermic and spontaneous reaction which contained physical adsorption, ion exchange and chelating reaction etc. The study indicated that the diamine -modified ordered mesoporous material SBA-15 is a potential sorbent which could be used for the aqueous Cd2+ removal.

[Pollution levels of perfluorochemicals in chicken eggs and duck eggs from the markets in Beijing].

Pollution levels of perfluorochemicals in eggs purchased from the markets in Beijing had been investigated. The egg samples of chicken and duck were collected from the 59 stalls of 14 main eggs wholesale markets in Beijing, respectively. Systematic analyses were made for seventeen kinds of perfluorochemicals (11 perfluorinated carboxylates (PFCAs), 3 perfluorinated sulfonates (PFSAs), perfluorooctane sulfonamide (FOSA), 2-perfluorooctylethanoic acid (FOEA) and 2H-perfluoro-2-decenoic acid (FOUEA) by a high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). The results showed that there was a certain perfluorochemical contamination in all egg samples. Nine kinds of perfluorochemicals were detected in chicken eggs, perfluorononanoic acid (PFNA), perfluoroheptanoic acid (PFHpA) and perfluorooctanoate acid (PFOA) are dominant, and their average concentrations were 0.105, 0.073 and 0.069 ng x g(-1), respectively. Ten kinds of perfluorochemicals were detected in the duck eggs, perfluorooctane sulfonate (PFOS) and PFOA are dominant, and their average concentrations were 0.378 and 0.296 ng x g(-1), respectively. Perfluoropentanoic acid ( PFPeA), perfluorotetradecanoic acid (PFTA), perfluorobutane sulfonate (PFBS) and 2-perfluorooctylethanoic acid (FOEA) were not detected in all samples. The total concentration of PFCs in the duck eggs was 3.4 times of that in the chicken eggs. A strong positive correlation (r = 0.954) was not only observed between of PFNA and PFHpA in chicken eggs, but also found between perfluoroundecanoic acid (PFUnDA) and perfluorotridecanoic acid (PFTrDA) in duck eggs (r = 0.915). The results of health-based risk assessment showed that there was little immediate risk of exposure to PFOS and PFOA via the consumption of chicken eggs and duck eggs purchased from the markets in Beijing.

[Synthesis of core/shell structured magnetic carbon nanoparticles and its adsorption ability to chlortetracycline in aquatic environment].

Magnetic carbon nanoparticles with core/shell structure (Fe3C/Fe@C) and large surface areas were synthesized via hydrothermal method followed with heat treatment under N2 atmosphere. The adsorbent has strongly magnetic cores and graphitized carbon shell. The removal efficiency of chlortetracycline (CTC) from aquatic environment by Fe3C/Fe@C was investigated. The results showed that Fe3C/Fe@C exhibited ultrahigh adsorption ability to CTC. The adsorption behavior of CTC on FeC/Fe@C fitted the pseudo-second-order kinetic model, and the adsorption equilibrium was achieved within 24 h. The adsorption ability of CTC increased with solution pH at pH 3.5-7.5, but decreased with further increase of pH (pH 7.5-8.5). CTC adsorption decreased with solution temperature and increased with ionic strength. As the concentration of coexisting humic acid in solution ranged in 10-50 mg x L(-1), the adsorption ability of CTC on Fe3C/Fe@C was only decreased by 10%-20%. Under the optimal conditions (pH = 7.5, T = 293 K), the maximum adsorption capacity of CTC on Fe3C/Fe@C calculated by Langmuir was 909 mg x g(-1), which was significantly higher than those obtained on sediment or minerals. More importantly, Fe3C/Fe@C adsorbed with CTC can be collected from water sample under a magnetic field rapidly for special disposal, which avoids secondary pollution of water. These results indicate that Fe3C/Fe@C is a potentially efficient, green adsorbent for removal of tetracycline antibiotics from aquatic environment.

[Degradation of norfloxacin by nano-Fe3O4/H2O2].

The degradation of norfloxacin in aquatic environment was studied in the presence of Fe3O4 nanoparticles and H2O2. The effects of solution pH, temperature, dose of catalysts and concentration of H2O2 on norfloxacin degradation were surveyed. The degradation behaviors of different substrates by nano-Fe3O4/H2O2 were investigated and the reaction mechanism of norfloxacin was discussed. The results showed that the reaction was strongly pH-dependent and favored in acidic solution (pH = 3.5). The removal efficiency of norfloxacin was enhanced with the increase of temperature, catalysts dosage and H2O2 concentration. The degradation efficiency of norfloxacin by nano-Fe3O4/H2O2 was significantly higher than those of sulfathiazole, phenolic and aniline compounds. In the presence of 4.4 mmol x L(-1) of H2O2, 0.80 g x L(-1) of Fe3O4 and T = 303 K, norfloxacin was degraded completely in 5 min. The F element in norfloxacin molecule existed totally as F(-) in solution within 5 min, and the removal efficiency of total organic carbon was 57% in 1 h. In the ESR spectrum of nano-Fe3O4/H2O2 system, the characteristic peaks of BMPO-*OH adduct was detected, however, the intensity of the peaks was reduced to 5% with the addition of tert-butanol, a strong *OH scavenger, and the degradation efficiency of norfloxacin was correspondingly decreased to 10% in 1 h. These results indicated that *OH played an important role on norfloxacin degradation, and the reaction proceeded based on a heterogeneous Fenton-like system.

[Adsorption kinetics of phenol on organic modified Lou soil].

Using batch experiment, the adsorption kinetics of phenol on both tillage layer (TL) and clay layer (CL) of Lou soil modified with cetyltrimethylammonium bromide (CTMAB, CB) at various ratio (100 CB and 50 CB) and cetyltrimethylammonium bromide + sodium dodecylsulphonate (CTMAB + SDS, CS) mixture were carried out, and its mechanism was discussed also. The results showed that two adsorption velocity parameters of phenol, total-adsorption-velocity (Vt) and fast-adsorption-velocity (Vf), on both layers of modified soil are 2.64-3.31 microg x (g x h)(-1), 39.19-61.23 microg (g x h)(-1) at low added phenol concentration respectively and 13.09-16.30 microg (g x h)(-1), 247.87-325.64 microg (g x h)(-1) at high added phenol concentration respectively at two experimental temperature, moreover, the two velocity parameters have a same sequence in different modification treatments, i.e., ordered by 100 CB > 120 CS > 50 CB > CK in TL treatment and by 100 CB > 50 CB > 120 CS> CK in CL treatment. These outcomes indicated that the modification on the both layers of Lou soil increases significantly the adsorption velocity of phenol. The adsorption of phenol is divided into two stages, fast adsorption and slow adsorption, in which the adsorption of phenol is primarily decided by the fast adsorption while it is affected little by slow adsorption. Therefore, the velocity parameters that relate with the fast adsorption have better correlation between them. The time of conversion (t(c)) between fast adsorption and slow adsorption in modified soil is less than 2 h, and shows a reverse sequence in different modification treatments compared to the adsorption velocity parameters. The adsorption velocity of modified CL to phenol is higher than that of modified TL. The adsorption velocity of organic modified soil to phenol can be increased by an increase of both temperature and added concentration of phenol. The exponential II kinetic model is the best model to describe the adsorption kinetic curves of phenol on modified soil, furthermore, the fitted parameter A has better correlation with the velocity parameters related to the fast adsorption while the fitted parameter--B, which can become a characteristic parameter to describe the adsorption velocity, has better correlation with the time of conversion to. The adsorption of phenol on the modified soil is primarily decided by the hydrophobic adsorption of organic phase on the surface of modified soil.

[Ionic exchange modification mechanism between organic modifier and Lou soil].

The ionic exchange modification mechanism between cationic organic modifier, cetyltrimethylammonium bromide (CTMAB), and two layers of Lou soil, tillage layer (TLLS) and clay layer (CLLS), were studied. The results show that a simple and effective index, sum of amounts of CTMAB and Ca2+/2 (Scc), can be used to judge the essence of modification mechanism between CTMAB and Lou soil. St(CC) demonstrates that the modification of CTMAB to two layers of Lou soil is the coexist of both ionic exchange and hydrophobic bond mechanism. The hydrophobic bond modification appears in the range of modification ratio 20%-28% CEC and linearly increases with an increase of both modification ratio and molar fraction of CTMAB, but its effects on the properties of soil become emergence just until 50% CEC modification ratio, and the hydrophobic bond mode exceeds the ionic exchange mode at about 100% CEC modification ratio and becomes main modification mechanism. The Vanselow selectivity coefficients show that the adsorption preference of Lou soil to CTMAB is stronger than that to calcium ion. The results of thermodynamics indicate that with an increase of modification ratio, the modification reaction transform from exothermic and entropy decrease to endothermic and entropy increase in the range of modification ratio 25% -100% CEC, while both pseudo enthalpy change and pseudo entropy change display a decrease trend in the range of modification ratio 100%-200% CEC, and in total, the modification reaction is a spontaneous reaction which controlled by entropy change in range of modification ratio 25% -100% CEC but controlled by enthalpy change in range of modification ratio 100%-200% CEC. The rationality of modification mechanism could be demonstrated by the results of thermodynamics.

Simultaneous adsorption of phenol and cadmium on amphoteric modified soil.

Surface modification is an effective way to enhance adsorption of pollutants by soil. In this study, we investigated the individual adsorption of cadmium ion (Cd(2+)) and phenol and also in combination by the clay layer of a loessial soil treated with the amphoteric modifier, duodalkylbetaine (BS-12). Three levels of BS-12 modification were compared in this experiment: (1) unmodified soil (CK), (2) modification with an amount of BS-12 equivalent to 50% of the soil's CEC (50BS) and (3) modification with an amount of BS-12 equivalent to 100% of the soil's CEC (100BS). Cd(2+) adsorption was 0.92-1.70 times higher in the amphoteric modified soil compared to unmodified soil. Adsorption isotherms for Cd(2+) displayed a L1-type shape. Phenol adsorption was 1.25-4.35 times higher in the amphoteric modified soil compared to the unmodified control. The adsorption isotherms of phenol on amphoteric modified soils were generally linear, but changed to L1-type isotherms for modified soil in the Cd(2+)+phenol treatment at 40 degrees C. The results clearly showed that amphoteric modified soil had the ability to simultaneously adsorb Cd(2+) and phenol. Cd(2+) adsorption by the amphoteric modified soil was related to the initial concentration of Cd(2+) in the supernatant. Cd(2+) adsorption in the 100BS treatment exceeded adsorption in the 50BS treatment when Cd(2+) initial concentrations were higher than approximate 200 microg mL(-1). Phenol adsorption by modified soils decreased in the order: 100BS>50BS>CK and was primarily determined by the surface hydrophobicity of the soil. For the unmodified soil, total adsorption in the Cd(2+)+phenol treatment was slightly lower compared to treatments that contained only Cd(2+) or phenol. This indicated an antagonistic effect between the adsorption of Cd(2+) and phenol, which was reduced after amphoteric modification. A comparison of temperature effects on Cd(2+) and phenol adsorption indicated that Cd(2+) was both physically and chemically adsorbed by the amphoteric modified soil, but phenol was primarily adsorbed physically.