Sage Journals: Discover world-class research

Abstract

Two novel weakly basic anion exchange resins BNH and BN2 bearing two different functional groups was fabricated via the two-step amination of chloromethylated polystyrene-divinylbenzene beads with dibutylamine and dimethylamine. The adsorption properties of BNH and BN2 for the 2-naphthalenesulfonic acid (NSA) removal from wastewater were compared with two synthesized monofunctional anion exchange resins BN0 and BN6 (derived from dimethylamine and dibutylamine, respectively). The experimental data revealed that the adsorption process on the four resins fitted well with the pseudo-second-order kinetics equation and the equilibrium isotherms were in good agreement with the Langmuir model. Thermodynamic analyses illustrated that 2-naphthalenesulfonic acid adsorption onto resins was an endothermic and spontaneous process. Importantly, BN2 still displayed relatively high adsorption capacity in the existence of Na₂SO₄, indicative of an excellent selectivity for 2-naphthalenesulfonic acid over sulfate than other resins. The obtained results elucidate that BN2 could have potential industrial application in effluent disposal fields because of its superior selectivity, acceptable kinetics, and desorption capability.

Keywords

2-Naphthalenesulfonic acid weakly basic anion exchange resin adsorption selectivity

Introduction

Owing to the discharge of abundant wastewater and hazardous substances, effluent from dye-related industries, such as tanning agent, printing, and textile has drawn widespread attention. Aromatic sulfonic acids (ASAs) have been widely used as dye intermediates, which results in many detrimental effects on human health and ecosystem because of the intrinsic physicochemical properties of the organic matters as well as the complex composition of the drainage (Labiadh et al., 2015; Li et al., 2017; Qin et al., 2014). Considering poor biodegradation property and high toxicity of recalcitrant compounds derived from naphthalene, benzene, phenol, aniline, traditional wastewater treatment techniques could not be easy to eliminate these pollutants (Güzel et al., 2015; Usha et al., 2010). Hence, it is imperative to develop effective destruction methods for ASAs from industrial sewage.

Adsorption is known as a high-efficiency, cost-effective, and easily available technique, and various adsorbents have been explored to remove ASAs. For instance, Gu et al. produced an adsorbent via introducing reed straw (RS) into sewage sludge-based activated carbon, and the presence of RS enhances the adsorption of 1-diazo-2-naphthol-4-sulfonic acid from aqueous solution (Gu et al., 2014). Zhang et al. (2016) proposed a novel macroporous amination resin, which exhibits superior affinity toward 8-amino-1-naphthol-3,6-disulfonic acid compared with three commercial resins. Among these adsorbents, weakly basic anion exchange resin is used extensively as a promising adsorbent on account of its huge specific surface area, fascinating regeneration performance and well-developed pore structures (Jia et al., 2011). Nevertheless, the charge of ASAs is always accompanied by excessive Na₂SO₄ or other inorganic salts which can forcefully compete for adsorption sites on adsorbent (Gu et al., 2013; Pan et al., 2008a). There are few reports about the removal of ASAs onto weakly basic resins due to their relatively low selectivity in saline wastewater. To circumvent this problem, some researchers found that the introduction of functional groups to adsorbent could not only better enhance the adsorption capacity of pollutants, but also improve its selectivity (Fu et al., 2016; Li et al., 2012; Zhang and Xu, 2014). In our previous work, we have introduced dicyclohexylamine and piperidine into chloromethylated polystyrene-divinylbenzene (Cl-PS-DVB) beads, respectively, to prepare two novel weakly basic anion exchange resins that can adsorb benzenesulfonic acid selectively from an aqueous solution containing sulfate (Sun et al., 2017). Nevertheless, the investment costs of dicyclohexylamine and piperidine are relatively high, and efforts of research have been devoted to synthesize more economical adsorbents in recent years. Accordingly, the functionalization of adsorbent using low-cost amines is essential to improve the adsorption selectivity.

In the present study, based on the stepwise reaction with two low-cost compounds, that is, dibutylamine and dimethylamine, novel weakly basic anion exchange resins containing different amino group were successfully prepared. 2-Naphthalenesulfonic acid (NSA) has been selected as a model compound of ASAs (Pan et al., 2008b). Batch experiments were conducted to test the adsorption performance of the resulting resins, especially to evaluate the selectivity of resins for NSA in existence of Na₂SO_4. The adsorption equilibrium isotherms, kinetics, and thermodynamics of various resins were systematically investigated and compared.

Materials and methods

Materials

NSA was purchased from Aladdin Industrial Corporation (Shanghai, China). Cl-PS-DVB beads holding 6% of cross-linking degree and 18% of chloride content were acquired from Zhengguang Co., Ltd (Zhejiang, China). Dibutylamine (DBA) and dimethylamine (DMA) were supplied by Sinopharm Chemical Reagent Co., Ltd (Shanghai, China). Reagents and solvents were of analytical reagent grade and purchased from Chengdu Kelong Chemical Co. Ltd (Sichuan, China).

Preparation of adsorbent and characterization

The amination of DBA and DMA onto Cl-PS-DVB beads was carried out as Figure 1. Briefly, 50 g Cl-PS-DVB beads were mixed with 80 g benzene in 500 mL three-necked flask with stirring at 303 K for 6 h, and then the swollen polymer particles were filtered out of the suspension. The mixture of 150 g DBA and 30 g anhydrous ethanol was dropped into the flask with stirring at 323 K for x h (where x is equal to 0, 0.5, 2, and 6 h). After amination, 10 g product was removed out and rinsed successively with deionized water, 4% HCl, deionized water, 4% NaOH and finally deionized water until the pH of the eluate was near neutral. Finally, the functional resin was extracted with anhydrous ethanol and dried at 318 K for 8 h. Next, the second amination was executed as follows: 120 g DMA was dropwise added to the flask with stirring at 323 K to react y h (where y is equal to 6, 6, 6, and 0 h) with remaining resin. The wash sequence and final procedure were as above.

Figure 1.

Scheme of the amination of dibutylamine and dimethylamine onto chloromethylated polystyrene-divinylbenzene beads.

According to the differences between x and y h in two-step amination, four kinds of weakly basic anion-exchange resins (BN0, BNH, BN2, and BN6) were synthesized. The total anion exchange capacity (TAEC) for four resins was obtained by performing a Mohr titration on the chloride ion replaced when resins were treated with excess sodium nitrate. The relationships between the exchange capacity and the bifunctional groups ratio of the four synthetic resins are presented in Table 1.

Table 1.

Effect of dibutylamine (DBA) and dimethylamine (DMA) content ratio on chloromethylated polystyrene-divinylbenzene.

x (h)	y (h)	Resin	Functional group	B/M^a	TAEC(mmol/g)
0	6	BN0	–N(CH₃)₂	0	3.80
0.5	6	BNH	–N(C₄H₉)₂, –N(CH₃)₂	0.14	3.77
2	6	BN2	–N(C₄H₉)₂, –N(CH₃)₂	2.56	3.66
6	0	BN6	–N(C₄H₉)₂	N/A	2.99

TAEC: total anion exchange capacity.

^aDBA and DMA functional group content ratio.

The FTIR spectra of resins were acquired on a Nicolet 5700 IR spectrometer (Madison, WI, USA) employing a pellet of powdered potassium bromide and adsorbent at ambient temperature. Specific surface area and pore structure of resins were analyzed by N₂ adsorption/desorption method at 77 K using an automatic surface area analyzer (Micromeritics ASAP-2020, USA).

Adsorption experiments

Four synthetic anion-exchange resins (BN0, BNH, BN2, and BN6) were utilized in this adsorption study. Isotherm studies for the four resins at three different temperatures (283, 293, and 303 K) were determined in 100 mL Erlenmeyer flasks containing 0.05 g resins and 50 mL solutions of NSA from a range of concentrations (1.20–12.00 mmol/L) agitated at 150 r/min for 24 h, respectively. For kinetic experiments, 500 mL flasks with 300 mL of 7.20 mmol/L NSA solution were performed at different time intervals under 303 K. The influence of initial solution pH on NSA removal was studied by varying the pH from 1 to 9 and diluted 0.1 M NaOH and 0.1 M H₂SO₄ solutions were utilized to adjust the solution pH throughout the experiment when necessary. The effect of ionic strength on the amount of NSA adsorbed was discussed over the Na₂SO₄ concentration, ranging from 1.41 to 7.04 mmol/L. The concentrations of NSA in supernatant solutions were assessed using UV-vis spectrophotometer at 275 nm wavelength, before and after the adsorption process. The adsorption amount (Q, mmol/g) was calculated according to equation (1)

Q = \frac{(C_{0} - C_{e}) V}{W}

(1)

where C₀ and C_e (mmol/L) are the initial and final concentration of NSA solution, respectively. V (L) is the solution volume W represents the weight of the dry resin (g).

Desorption procedure

For desorption study, 0.05 g of four resins were added into 50 mL of 7.20 mmol/L NSA solution agitated at 150 r/min for 24 h, subsequently the NSA loaded adsorbents was filtered and soaked in 0.1 M NaOH solution for 2 h at 323 K. Finally, the amounts of NSA eluted were measured. The desorption efficiency (%) was calculated by the following equation

DE = M_{d} / M_{a} \times 100

(2)

where DE is the percentage of NSA desorbed into 0.1 M NaOH, M_a is the amount of NSA adsorbed on resins, and M_d is the amount of NSA desorbed from resins by NaOH.

Results and discussion

Characterization of resins

As seen in Figure 2, the absorption bands at 1367 and 1018 cm⁻¹ corresponds to the C–N stretching vibration appeared after amination, and the N–H vibration of amine resin is due to its 2757 cm⁻¹ band (Kaušpėdienė et al., 2013; Siddiqi et al., 2018; Wang et al., 2007). The aforementioned phenomena validated the successful synthesis of amine resins.

Figure 2.

FTIR spectra of BN0, BN2, BN6, and chloromethylated polystyrene-divinylbenzene beads.

Figure 3 depicts the nitrogen adsorption/desorption isotherm, and the BET surface area and total pore volume of four resins are exhibited. It can be found that the BET surface area is in the same level, but the TAEC of resins (Table 1) indicates a decreasing trend with the increase of functional group size, resulting from the steric hindrance effect of different functional groups (Subramonian and Clifford, 1988).

Figure 3.

Nitrogen adsorption/desorption isotherm obtained at 77 K for four resins.

Effects of pH

Considering the pH of wastewater is of great significance to the adsorption process, the influence of initial pH for NSA uptake onto the four resins are shown in Figure 4. When pH is 2, the protonation of the amino groups can enhance the electrostatic attraction between resins and anions of NSA. Moreover, protonated amino groups possess a strong binding force with naphthalene ring π electron cloud of NSAs to form N–H···π hydrogen bond, which leads to high adsorption of NSA (Burley and Petsko, 1986). When pH is lower than 2, the low adsorption capacity for NSA could be ascribed to the competitive adsorption with the added sulfate anions for pH adjustment (Pan et al., 2005). When pH is higher than 2, a large of number of amino groups are deprotonated, resulting in electrostatic repulsion between resins and anions of NSA and consequently, the adsorption capacities would be weakened with the increasing pH value (Hameed et al., 2008; Pei et al., 2013). Interestingly, when pH is in the range of 2–7, the adsorption of NSA on resin BN0 with only dimethylamine functional groups is seriously affected by pH than other resins containing dibutylamine functional groups. This may be due to the fact that the pKa of dibutylamine adsorption sites is larger than that of dimethylamine adsorption sites, resulting in a stronger protonation capacity at the same pH. Therefore, pH 2.0 was employed in the following studies.

Figure 4.

Effects of initial pH on the adsorption of 2-naphthalenesulfonic acid on BN0, BNH, BN2, and BN6.

Adsorption kinetics

Figure 5 shows the kinetic data of NSA adsorption by the four resins at pH 2.0 and 303 K. The data were analyzed using two kinetic models: the pseudo-first-order and pseudo-second-order. The equations are listed as follows (Jiménez-Cedillo et al., 2013; Zhang et al., 2016)

Q_{t} = Q_{e} (1 - e^{- k_{1} t})

(3)

Q_{t} = \frac{k_{2} Q_{e}^{2} t}{1 + k_{2} Q_{e} t}

(4)

where Q_e and Q_t (mmol/g) are the adsorption capacities of NSA adsorbed at equilibrium and any time (min), respectively. k₁ (min⁻¹) and k₂ (g mmol⁻¹ min⁻¹) are the rate constants of the pseudo-first-order and pseudo-second-order kinetic models, respectively. The fitting data are displayed in Table 2. According to the coefficients of determination (R²) and the chi-square (χ²), the pseudo-second-order model is more suitable to describe the adsorption behavior of NSA onto the four resins. Additionally, the value of k₂ increased in the order: BN6 > BN0 > BNH > BN2, thereby indicating that the large alkyl group substituents on positive nitrogen active site could improve steric and hydrophobic effect (Donia et al., 2011). BN0 with the smaller alkyl chain derived from dimethylamine make the steric hindrance minimize. Since the exchange capacity of BN6 is much lower than that of BN0, the k₂ value of BN6 is the largest. Therefore, the steric hindrance of BN2 is large due to the large alkyl group derived from dibutylamine, which results in a relatively slow speed.

Figure 5.

Pseudo-second-order model for the adsorption of 2-naphthalenesulfonic acid onto BN0, BNH, BN2, and BN6.

Table 2.

Adsorption kinetic parameters of 2-naphthalenesulfonic acid adsorption onto BN0, BNH, BN2, and BN6.

Resin	Pseudo-first-order model				Pseudo-second-order model
Resin	Q_e,cal (mmol/g)	k₁ × 10⁻³	R ²	χ²	k₂ × 10⁻³	R ²	χ²
BN0	5.21	19.98	0.9864	0.0361	1.51	0.9977	0.0061
BNH	4.74	12.7	0.9909	0.0182	0.83	0.9967	0.0065
BN2	4.55	9.28	0.9939	0.0107	0.51	0.9964	0.0064
BN6	2.87	18.31	0.9650	0.0243	2.64	0.9853	0.0102

Adsorption isotherm and thermodynamics

The adsorption isotherm of NSA on four resins at different temperatures are depicted in Figure 6. Langmuir and Freundlich equations (Zhu et al., 2016) (equations (5) and (6)) were adopted to fit for the experimental data, and the fitting results are given in Table 3.

Langmuir model : Q_{e} = \frac{Q_{m} K_{L} C_{e}}{1 + K_{L} C_{e}}

(5)

Freundlich model : Q_{e} = K_{F} C_{e}^{1/n}

(6)

where Q_e (mmol/g) is the adsorption capacity at equilibrium and Q_m (mmol/g) is the monolayer adsorption capacity. K_L (L/mmol) is the Langmuir constant. K_F (mg^{1 − 1/n} L^1/n/g) and n are Freundlich constants.

Figure 6.

Adsorption isotherm of 2-naphthalenesulfonic acid onto resins simulated by the Langmuir model.

Table 3.

The adsorption isotherm model constants for the adsorption of 2-naphthalenesulfonic acid onto resins at 283, 293, and 303 K.

Resin	T (K)	Langmuir model				Freundlich model
Resin	T (K)	Q_m(mmol/g)	K_L(L/mmol)	R ²	χ²	K_F(mg^{1 − 1/n} L^1/n/g)	n	R ²	χ²
BN0	283	5.03	8.51	0.9927	0.0154	4.22	3.86	0.9131	0.1830
	293	5.57	9.86	0.9807	0.0530	4.97	3.54	0.9373	0.1718
	303	5.91	10.07	0.9906	0.0260	4.92	3.18	0.9264	0.2035
BNH	283	4.27	5.18	0.9881	0.0157	3.23	3.76	0.9287	0.0939
	293	5.02	7.71	0.9729	0.0569	4.16	3.68	0.9157	0.1769
	303	5.77	8.95	0.9929	0.0201	5.12	3.46	0.9266	0.2089
BN2	283	3.67	3.68	0.9902	0.0081	2.59	3.77	0.9048	0.0793
	293	4.29	11.25	0.9760	0.0356	3.61	4.57	0.8978	0.1521
	303	5.26	13.17	0.9988	0.0029	4.7	4.29	0.8709	0.3139
BN6	283	3.7	2.68	0.9827	0.01415	2.42	3.34	0.9326	0.0551
	293	3.98	4.38	0.9999	7.92E-06	2.91	3.89	0.8916	0.1141
	303	4.12	11.32	0.9915	0.0111	3.45	4.88	0.8680	0.1722

The constants (K_L, K_F, and n), the calculated Q_m, R² and χ² for the two isotherm models are calculated and listed in Table 3. The Langmuir model appears to provide the best fit for the data than the Freundlich model for the four resins, judging from the values of R² and χ². The Langmuir model can well describe that the adsorption of NSA onto resins occurs in a monolayer under the surface (Langmuir, 2015). Note that the adsorption capacity of four resins increases a little when the temperature increases, signifying a special characteristic of electrostatic interaction without a big variation with temperature (Zhang et al., 2016). Moreover, the Q_m of NSA onto all the resins change in the same order with the total anion exchange capacity: BN0 > BNH > BN2 > BN6. In view of their same PS-DVB matrix, different adsorption performance of BN0, BNH, BN2, and BN6 could be ascribed to the different functional group on the surface of the adsorbent. Thus, the electrostatic attraction between sulfonic group of NSA and amine group can be a primary adsorption mechanism, compared with other weak interactions such as hydrophobic and π–π interactions.

The thermodynamic parameters, the free energy change (ΔG⁰), enthalpy change (ΔH⁰), and entropy change (ΔS⁰) can be calculated by the following equations (Lima et al., 2019; Liu, 2009; Liu and Liu, 2008)

Δ G^{0} = - R T \ln K_{e}

(7)

\ln K_{e} = \frac{Δ S^{0}}{R} - \frac{Δ H^{0}}{R T}

(8)

where R is the gas constant (8.314 J/(mol·K)), and T is the temperature (K). K_e is the equilibrium constant without units. ΔH⁰ and ΔS⁰ were determined using the slope and intercept of the plots of lnK_e versus 1/T. The thermodynamic parameters are given in Table 4. The adsorption of NSA onto BN0, BNH, BN2, and BN6 is spontaneous at 283, 293, and 303 K, identifying from the negative ΔG⁰ values. Besides the values of ΔG⁰ become more negative with the rise of temperature, suggesting the adsorption is more favorable at a higher temperature. The positive ΔH⁰ reveals that the adsorption reaction is endothermic. The ΔS⁰ is positive, which illustrates that the increased randomness at the solid-solution interface during the adsorption process.

Table 4.

The thermodynamic parameters of adsorption for 2-naphthalenesulfonic acid onto BN0, BNH, BN2, and BN6.

Resin	T (K)	ΔG⁰ (kJ/mol)	ΔH⁰ (kJ/mol)	ΔS⁰ (J/mol)
BN0	283	−21.29	6.04	96.74
	293	−22.40
	303	−23.22
BNH	283	−20.12	19.62	140.75
	293	−21.80
	303	−22.92
BN2	283	−19.32	45.81	231.37
	293	−22.72
	303	−23.90
BN6	283	−18.57	51.16	245.73
	293	−20.43
	303	−23.52

Effect of Na₂SO₄ and adsorption selectivity

Previous studies have demonstrated that the existence of anions inevitably reduces the uptake of ASAs because of the competition for adsorption sites. Sodium sulfate (Na₂SO₄) was chosen as representative inorganic salts. As presented in Figure 7, the adsorbed amounts of NSA on BN0 and BN6 decreased sharply with the increase in the concentration of Na₂SO₄ from 1.41 to 7.04 mmol/L. Nonetheless, a slight dip on BNH and BN2 could be observed. The distribution ratio K_d (L/g) was determined by equation (9) for the purpose of quantifying the selectivity of the four resins (Pan et al., 2005)

K_{d} = \frac{(C_{0} - C_{e})}{C_{e}} \cdot \frac{V}{m} = \frac{Q_{e}}{C_{e}}

(9)

Figure 7.

Effect of Na₂SO₄ concentration in solution on 2-naphthalenesulfonic acid adsorption onto resins at 303 K.

The resulting K_d values of the four resins at different initial Na₂SO₄ concentration are exhibited in Figure 8. Among the four resins, the K_d values of the monofunctional resins BN0 and BN6 are much lower than those of BN2 and BNH at the identical amount of Na₂SO₄ addition. At the same time, the K_d values of BN0 are only higher than those of BN6. The above-mentioned results can be attributed to the following reasons. First of all, as a divalent anion, SO₄²⁻ needs to be exchanged with two contiguous active sites on the resin. Consequently, it is harder for SO₄²⁻ to attach to the amine groups of the long alkyl chain. Moreover, longer alkyl chain is a positive factor affecting the hydrophobicity of resin and could make resin more selective in adsorbing organic anions than inorganic anions such as SO₄²⁻ with higher hydrophilicity (Luo et al., 2015). Besides, BN2, BNH, and BN6 are relatively insensitive sensitive to sulfate ion, and the lowest uptake of NSA onto BN6 is caused by its the lowest exchange capacity. Thus, the highest selectivity of novel dual functional exchanger BN2 for NSA may be ascribed to –N(C₄H₉)₂ to enhance the selectivity as well as –N(CH₃)₂ to increase the exchange capacity.

Figure 8.

K_d values calculated with different concentrations of Na₂SO₄.

Desorption

Desorption is of great importance in evaluating the possibility of reusing adsorbent. Taken into account the fact that the four resins possess lower adsorption capacity toward NSA at increased pH. Hence, the desorption of NSA adsorbed on resin was carried out using 0.1 M NaOH solution. Figure 9 displays that the desorption efficiency of BN0, BNH, BN2, and BN6 is 83.3%, 91.9%, 95.2%, and 91.2%, respectively, implying that these resins possess better desorption performance than that of commercial weak-base exchanger D-301 which has been applied in the removal of ASAs from industrial wastewater (Pan et al., 2005, 2008a). In addition, NaOH is able to desorb NSA, which may further manifest that the predominant adsorption affinities between NSA and BN2 are electrostatic interaction.

Figure 9.

Desorption efficiency of different resins.

Conclusion

In summary, two novel dual functional weakly basic anion exchange resins BNH and BN2 were successfully prepared, and two monofunctional anion exchange resins BN0 and BN6 were functionalized with dimethylamine and dibutylamine, respectively. Comparative studies on adsorption performances of BN0, BNH, BN2, and BN6 indicated that all adsorption process could be well described using the pseudo-second-order kinetics, and equilibrium data obeyed the Langmuir model. Thermodynamics analysis demonstrated the NSA uptake was an endothermic and spontaneous process. Furthermore, BN2 displayed the best adsorption capacity toward NSA in water containing competitive sulfate, and the largest values of K_d exposed that that optimizing the content ratio of dual functional groups can enhance the adsorption selectivity for NSA of the resin. Compared with other resins, better desorption performance of BN2 exhibited its potential reusability. Consequently, the weakly basic anion exchange resin BN2 with dual functional groups is qualified for the removal of NSA and other similar aromatic sulfonic compounds from the effluent.

Footnotes

Declaration of Conflicting Interests

The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Funding

The author(s) disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: This work was supported by the National Natural Science Foundation of China (no. 51578131), and the project was funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions.

References

Burley

Petsko

(1986) Amino-aromatic interactions in proteins. FEBS Letters 203: 139.

Donia

Atia

Mabrouk

(2011) Fast kinetic and efficient removal of As(V) from aqueous solution using anion exchange resins. Journal of Hazardous Materials 191: 1–7.

Xin

et al . (2016) Selective adsorption and separation of organic dyes from aqueous solution on polydopamine microspheres. Journal of Colloid and Interface Science 461: 292–304.

Guo

Zhou

et al . (2014) Enhanced adsorptive removal of naphthalene intermediates from aqueous solution by introducing reed straw into sewage sludge-based activated carbon. Environmental Science and Pollution Research 21: 2043–2053.

Zhu

Zhang

et al . (2013) A comparative study of aerobically digested and undigested sludge in preparation of magnetic chars and their application in 1-diazo-2-naphthol-4-sulfonic acid adsorption. Bioresource Technology 136: 719–724.

Güzel

Sayğılı

et al . (2015) New low-cost nanoporous carbonaceous adsorbent developed from carob (Ceratonia siliqua) processing industry waste for the adsorption of anionic textile dye: Characterization, equilibrium and kinetic modeling. Journal of Molecular Liquids 206: 244–255.

Hameed

Tan

IAW

Ahmad

(2008) Adsorption isotherm, kinetic modeling and mechanism of 2,4,6-trichlorophenol on coconut husk-based activated carbon. Chemical Engineering Journal 144: 235–244.

Jia

Shang

et al . (2011) Iron-impregnated weakly basic resin for the removal of 2-naphthalenesulfonic acid from aqueous solution. Journal of Chemical & Engineering Data 56: 3881–3889.

Jiménez-Cedillo

Olguín

Fall

et al . (2013) As(III) and As(V) sorption on iron-modified non-pyrolyzed and pyrolyzed biomass from Petroselinum crispum (parsley). Journal of Environmental Management 117: 242–252.

10.

Kaušpėdienė

Gefenienė

Kazlauskienė

et al . (2013) Simultaneous removal of azo and phthalocyanine dyes from aqueous solutions using weak base anion exchange resin. Water Air & Soil Pollution 224: 1769.

11.

Labiadh

Oturan

Panizza

et al . (2015) Complete removal of AHPS synthetic dye from water using new electro-fenton oxidation catalyzed by natural pyrite as heterogeneous catalyst. Journal of Hazardous Materials 297: 34–41.

12.

Langmuir

(2015) The adsorption of gases on plane surfaces of glass, mica and platinum. Journal of the American Chemical Society 40: 1361–1403.

13.

Jiang

Yin

(2012) Multi-responsive microgel of hyperbranched poly(ether amine) (hPEA-mGel) for the selective adsorption and separation of hydrophilic fluorescein dyes. Journal of Materials Chemistry 22: 17976–17983.

14.

Zhang

Shi

(2017) Selective adsorption of aromatic acids by a nanocomposite based on magnetic carboxylic multi-walled carbon nanotubes and novel metal-organic frameworks. Applied Surface Science 416: 672–680.

15.

Lima

Hosseini-Bandegharaei

Moreno-Piraján

et al . (2019) A critical review of the estimation of the thermodynamic parameters on adsorption equilibria. Wrong use of equilibrium constant in the Van’t Hoof equation for calculation of thermodynamic parameters of adsorption. Journal of Molecular Liquids 273: 425–434.

16.

Liu

(2009) Is the free energy change of adsorption correctly calculated? Journal of Chemical & Engineering Data 54: 1981–1985.

17.

Liu

(2008) Biosorption isotherms, kinetics and thermodynamics. Separation and Purification Technology 61: 229–242.

18.

Luo

Gao

et al . (2015) Modification of reduced-charge montmorillonites by a series of Gemini surfactants: Characterization and application in methyl orange removal. Applied Surface Science 324: 807–816.

19.

Pan

Zhang

Pan

et al . (2008a) Removal of aromatic sulfonates from aqueous media by aminated polymeric sorbents: Concentration-dependent selectivity and the application. Microporous and Mesoporous Materials 116: 63–69.

20.

Pan

Zhang

Pan

et al . (2008b) Efficient removal of aromatic sulfonates from wastewater by a recyclable polymer: 2-Naphthalene sulfonate as a representative pollutant. Environmental Science & Technology 42: 7411–7416.

21.

Pan

Zhang

Meng

et al . (2005) Sorption enhancement of aromatic sulfonates onto an aminated hyper-cross-linked polymer. Environmental Science & Technology 39: 3308–3313.

22.

Pei

Sun

et al . (2013) Adsorption characteristics of 1,2,4-trichlorobenzene, 2,4,6-trichlorophenol, 2-naphthol and naphthalene on graphene and graphene oxide. Carbon 51: 156–163.

23.

Qin

Dai

Zhou

et al . (2014) Desalting and recovering naphthalenesulfonic acid from wastewater with concentrated bivalent salt by nanofiltration process. Journal of Membrane Science 468: 242–249.

24.

Siddiqi

Siraj

Khalid

et al . (2018) Thermally stable epoxy polymers from new tetraglycidyl amine-based resin. Journal of Thermal Analysis & Calorimetry 132: 1–10.

25.

Subramonian S and Clifford

(1988) Monovalent/divalent selectivity and the charge separation concept. Reactive Polymers Ion Exchangers Sorbents 9: 195–209.

26.

Sun

Zuo

Luo

et al . (2017) Adsorption behavior of benzenesulfonic acid by novel weakly basic anion exchange resins. Journal of Environmental Sciences 54: 40–47.

27.

Usha

Sanjay

Gaddad

et al . (2010) Degradation of h-acid by free and immobilized cells of Alcaligenes latus. Brazilian Journal of Microbiology 41: 931–945.

28.

Wang

Fei

Chen

et al . (2007) Adsorption thermodynamics and kinetic investigation of aromatic amphoteric compounds onto different polymeric adsorbents. Journal of Environmental Sciences 19: 1298–1304.

29.

Zhang

Wang

Yang

et al . (2016) A comparative study on the adsorption of 8-amino-1-naphthol-3,6-disulfonic acid by a macroporous amination resin. Chemical Engineering Journal 283: 1522–1533.

30.

Zhang

(2014) Wrapping carbon nanotubes with poly (sodium 4-styrenesulfonate) for enhanced adsorption of methylene blue and its mechanism. Chemical Engineering Journal 256: 85–92.

31.

Zhu

Zhang

Liu

et al . (2016) Effect of polymeric matrix on the adsorption of reactive dye by anion-exchange resins. Journal of the Taiwan Institute of Chemical Engineers 62: 98–103.

Removal of 2-naphthalenesulfonic acid using novel dual functional weakly basic anion exchange resins from aqueous solution

Abstract

Keywords

Introduction

Materials and methods

Materials

Preparation of adsorbent and characterization

Adsorption experiments

Desorption procedure

Results and discussion

Characterization of resins

Effects of pH

Adsorption kinetics

Adsorption isotherm and thermodynamics

Effect of Na2SO4 and adsorption selectivity

Desorption

Conclusion

Footnotes

Declaration of Conflicting Interests

Funding

References

Effect of Na₂SO₄ and adsorption selectivity