Biosorption of Dimethyl Phthalate From Aqueous Solution Using Yeast-based Silver Nanoparticle

doi:10.21203/rs.3.rs-1594332/v1

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Biosorption of Dimethyl Phthalate From Aqueous Solution Using Yeast-based Silver Nanoparticle

https://doi.org/10.21203/rs.3.rs-1594332/v1

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Biosorption provides the reduction of pollution effluents to environmentally satisfactory cutoff points in a financially savvy and ecologically benevolent way by using microorganisms and nanotechnology. Due to its availability and dimethyl phthalate sorption capability, Saccharomyces cerevisiae was considered for biosorption of dimethyl phthalate in the last decade. In this Study dried S.cerevisiae with Silver Nanoparticle was used for dimethyl phthalate biosorption. The influence of operative conditions such as pH, temperature, initial DMP concentration, adsorbent dosage, and contact time was examined. Optimization of operational parameters shows that the optimum concentrations of YB-AgNPs for effective removal of DMP were 700 µg/ml at pH 5 after 5mins and 0.5g at 30-50⁰C for YB-AgNPs biomass concentration. Using three isothermal models, the data obtained from the experiment were analyzed, and the parameters were estimated for each isothermal and related coefficient. The Langmuir isotherm model in this study suits best for biosorption of Dimethyl phthalate. In order to evaluate biosorption kinetics, three kinetic models were used, and it was observed that biosorption follows a second pseudo-order model of a ratio coefficient as high as (R² = 1). The analysis of thermodynamics test data revealed that the process was spontaneous and feasible. The mechanism of biosorption was defined as physisorption. Therefore, the results obtained show that inactive YB-AgNPs can be an easy and affordable alternative to costly activated carbon for the treatment of dimethyl phthalate from wastewater.

Biosorption

Dimethyl Phthalate

Yeast Based

Silver Nanoparticle

Thermodynamics

One of the key endocrine-disrupting chemicals (EDCs) in an aquatic setting is known to be phthalate esters (PAEs). For some items such as toys, skincare, food packaging, medication, and medical electronic devices, PAEs are primarily used as plasticizers. As a result of an increase in waste plastics, there will be a continuous effluent of PAEs into the ecosystem PAEs can be present in the air, ocean, soil, living organisms, and many more and this has become the highest pollutant in the nation which has been widely studied by (Zhang et al. 2018). One of the famous phthalate acid esters is called Dimethyl phthalate (DMP).

DMP is made up of a chemical structure that is identical to a form like benzene bound in the cyclic position to methyl ester groups. It has been used as a raw material for plasticizers, instruments, body parts of cars, food packaging products, insecticides, etc.

Presently, because of its ability to float freely in water, it has become the most commonly known waste disposal and ocean (Roslev et al. 2007). Since its general use and its refractory biodegradability, it is one of the short-chained esters) which are widespread in the environment (Yuan et al. 2011). In various natural studies, DMP has been found, such as in freshwaters, coastal waters, soil, and silt. The key possible reasons for DMP to enter the aquatic environment are the leakage of wastewater from generation, handling exercises, and the release from the use and transfer of phthalate ester-containing materials (Vanaja et al. 2013).

S.cerevisiae (Yeast) is straight forward for large scale production that uses a simple fermentation method and an inexpensive growth media, the yeast can be cultivated readily. However, yield product of the biomass is also relatively high, when it is compared to another forms of microbial product of biomass waste (Wong et al. 2004). S.cerevisiae is considered safe; biosorbents generated using it will simply be recognized by society when used along these lines. The mechanism of biosorption for dimethyl phthalate removal is an ideal model organism to classify. Therefore extracting toxins from industrial waste water before environmental discharge, various physico-chemical and biological methods are widely used. Biological methods have been one of the method that have been used in the past, for example regular treatments for waste and purification of aquatic environment. Almost all biological materials such as macro algae likewise biomass of plants, animals and some other related products (e.g. chitosan) are effective for bio-sorption (Fomina and Gadd 2014).

Biosorption is a physiochemical operation of a number of processes, including precipitation, absorption, complexation of the surface, and adsorption. In traditional and environmental biotreatment systems, this is important. Organic substances' adsorption depends on their molecular size, chemical composition, and polarity. The bigger the molecule, the greater the sorption it normally has. Based on the pH value, they can thus be adsorbed precisely on different surfaces. Organic material adsorption is also significantly affected by the polarity of the latter (Julinová and Slavík 2012). Nanotechnology is any technology that deals with the application of nanosized material manipulation techniques. Nanomaterial and nanoparticles have been recognized as particles falling within the range of 1-100 nm with no less than two dimensions (Kumar et al. 2016). There are two main feature of nanoparticles that render them to be more effective as sorbents: they have a much larger surface area on a mass basis than bulk particles, they have the ability to absorb and attach many different surfaces and contaminants in the waste water, they can bind with heavy metals, some of which are harmful to living cells. A high ratio of area-to-volume can be the key feature for AgNPs, enabling comprehensive nanostructure exploitation in many fields, e.g. environmental waste water remediation, biotechnology, medicine, agriculture and the food industry. The market for AgNPs, however, is not restricted to consumer products; the possible use of these nanomaterial has been illustrated in biotechnological processes such as environmental remediation and wastewater treatment processes (Parada et al. 2019).

Recently, the combination of biosorbents and nanotechnology has been explored. Another way of increasing the bioeconomy of composite materials with the right properties could be the use of nanoparticles and biosorbents

Due to environmental concerns and health hazards, dimethyl phthalate removal from pharmaceutical waste water is important. This study will include an alternative method to extract dimethyl phthalate and demonstrate that YB-AgNPs can be cheap and easy to prepare in the laboratory for economic reasons.

2.1 Materials

The reagent was collected from the environmental (preparatory) laboratory of Cyprus International University, North Cyprus.

Preparation Dimethyl Phthalate Solution

2000µg/ml of dimethyl phthalate stock solution was prepared. All trials of various concentrations were set up by diluting the prepared stock solution serially.

Preparation of Adsorbent

Yeast ( S.cerevisiae )

Yeast was incubated on a shaker for 24 hrs. The cell was then harvested after centrifuging at 6000 rpm for 10minutes. The resulting biomass was rendered inactive by autoclaving for 72 hrs at 60^oc. The obtained dried powdered yeast was stored in the refrigerator and used as a biosorbent in the experiment.

Preparation of Silver Nanoparticles (Ag-NPs)

Silver nanoparticles (AgNps) were synthesized by the co-precipitation method. AgNps was prepared by dissolving 1.8g of gelatine in 80ml of deionized water, with continuous stirring, and 25ml of silver nitrate solution (1M) and 18g of ascorbic acid (2M) were added. Then ıt was moved to a water bath at 80^oc for 30mins. The resulting suspension containing AgNp was centrifuge. The final product was heated up at 50^oc for 12hrs to obtain dried Silver nanoparticles and then store in a desiccator (Chekin and Ghasemi 2014).

Preparation of Yeast Based Silver Nanocomposite (YB-AgNPs)

In the 8:1 ratio, the prepared Yeast biomass and the Silver nanoparticles were blended together. To get the YB-AgNP

Batch Studies

The amount adsorbed per unit mass of adsorbent (Q_e) was obtained from the equation;

$$\left(\text{Q}\text{e}=\left(\frac{\text{C}\text{o}-\text{C}\text{t}}{\text{M}}\text{V}\right)\right) \left(1\right)$$

$$\left(\text{Q}\text{t}=\left(\frac{\text{C}\text{o}-\text{C}\text{t}}{\text{M}}\text{V}\right)\right) \left(2\right)$$

Removal efficiency (%):

$$\left(\text{Q}\text{t}=\left(\frac{\text{C}\text{o}-\text{C}\text{e}}{C\text{o}\times 100}\right)\right) \left(3\right)$$

Q_e and Q_t is the adsorption capacity mg/g at the equilibrium, it is time and C_o, C_e and Ct are DMP concentration in the solution (mg/L) at the initial, equilibrium and at time t, respectively; V is the volume of the solution (L); and m is the dry mass of the biosorbent.

3.1 Characterization of the Biosorbent

Below is the result of the Characterization of Silver nanoparticles (AgNPs).

Scanning Electron Microscope (SEM) Analysis of Silver Nanoparticle

The SEM image of the silver Nanoparticle is given in Fig. (1), this image shows the uniformity in the size of the nanoparticle.

Fourier Transforms Infrared (FTIR) Spectroscopy of Silver Nanoparticle (AgNPs)

FTIR measurements were performed to recognize the involvement of various functional groups in biomolecules responsible for bioreduction of Ag + and capping/stabilization of silver nanoparticles. The observed strong bands were compared with the standard values to classify the functional groups. At 2921, 2856, 1743, 1631, 1377, 1240, 1043 and 596 cm-1, the FTIR spectrum displays absorption bands suggesting the presence of capping agent with nanoparticles. It has a functional group of O-H. The spectrum confirmed the presence of aromatic amine, amide group, phenolic group and secondary alcohols which may act as a reducing agents for synthesis of silver nanoparticle similar result was also confirm (Wang et al. 2017).

Effect of environmental parameters

Effect of pH

The pH is the most important effect in the study of biosorption. The sorption of the sorbate on the sorbent is often influenced by the increase or decrease in the pH. It allows us to understand the physiochemical relationship between sorbate and sorbent. The solution's pH has a significant influence on DMP uptake because it determines the adsorbent's surface charge and also determines the speciation of the adsorbate and degree of ionization (DMP). This analysis was done with 100ml each of a different concentration of 250–500µg/ml respectively which contained a dried amount of 0.5g of Yeast Based Silver Nanoparticle (sorbent) at different pH of range 3–6 at 30⁰c to study the initial pH effect on the ability dimethyl phthalate removal. As shown in Fig. 3. It can be observed that increasing pH tends to increase in the DMP adsorption quantity (Fomina and Gadd 2014). This increase gradually reach the maximum value sharply at pH 5 and then it remained constant over a wide pH region. It was also observed that sorption rate of DMP was slightly decreased at a pH of 6.0 due to the dimethyl phthalates ion struggle to hydrolyse and precipitate exceedingly by Biosorption (Soni et al. 2012). Further experiments were performed at the initial pH of value 5 in this analysis.

Effect of Temperature

The temperature effect on dimethyl phthalate biosorption was carried out by analyzing temperatures between 30 and 50ºC at pH 5, by using different concentrations of 500–900 µg/ml of dimethyl phthalate with 0.5g of Yeast Based Silver Nanoparticle (Awad, and Erkurt 2014) with the equation above, the equilibrium value of dimethyl phthalate at various temperature range was calculated. The effect of temperature on biosorption by YB-AgNPs is shown in Fig. (4).

However, it can be observed in Fig. (4) that the optimum temperature for this study is 50^oC. This condition (50^oC) is where the maximum DMP removal (92%) was observed. The effect of temperature in Fig. (4) below show that less DMP remain when the temperature was 50ºC, while the concentration of DMP in the aqueous solution increase with the increase in temperature in fig.( 4). In the aqueous solution the temperature has more effect on DMP biosorption. This may be due to the low temperature, the viscosity of DMP solution on the surface of YB-AgNPs (Wang and Chen 2006). It was also shown from the result that the adsorption study is an Endothermic (Osman et al. 2013). The result of this study was further confirmed that, increases in temperature have much influence in the adsorption study.

The Effect of Initial DMP Concentration

The initial concentration of DMP has great influence on biosorption process. The effect of different initial DMP concentration (500 µg/mto 900 µg/ml) of DMP on biosorption was investigated for 60mins. Steady Increment in likely trends, in biosorption capacity as initial concentration increases from 500 to 900 µg/ml can be observed. The oxidation rate of DMP was increased with respect to increase in the initial concentration of DMP in the reaction Fig. (5), (Jabesa and Ghosh 2016).

Effect of Contact Time

Interaction between the elimination of DMP with contact time was observed to examine the rate at which DMP were removed by YB-AgNPs at different initial DMP concentration and also at different pH and constant concentration of DMP (700 µg/ml). The biosorption of DMP in YB-AgNPs was studied to be a fast process.

It was significant that the rate of biosorption was rapid in the initial stage (5 mins), thereafter continue at a slower and steadily and eventually reached equilibrium at different contact time for different concentration at initial of DMP (Fig. 6). The higher the DMP initial concentration, the higher time required to reach equilibrium. It was noticed that the rate of DMP sorption is not affected by contact time. Under the below conditions, (Fig. 6) shows that the adsorption amount reaches equilibrium value at 30 min and a subsequent little change of sorption occurs (i.e, remains constant thereafter), hence there was no significant changes at contact time. A similar result was obtained when methylene blue dye was removed using polydopamine microsphere (Esfandian et al. 2016).

Effect of Biosorbent Dosage

The effect of biosorbent dosage was determined on the biosorption of DMP. It was observed from the graph that as the biosorbent dosage increased, there was decrease in biosorption. It also means that the lower the dosage of the biosorbent used the higher the biosorption capacity (mg/g). The biosorbent dosage with the highest biosorption capacity is 0.25g (1752 mg/g) followed by 0.5g (900mg/g) while the lowest biosorption capacity was recorded using 1g (512mg/g) which was the highest biosorbent dose used in this experiment (Fig. 7).

Therefore, an increase in biosorbent dosage brought about an increase in the percentage of DMP removal (Fig. 7). The highest percentage of DMP removal was observed with 1g biosorbent dosage (75.29%) followed by 0.5g (66.18%) while the lowest percentage of DMP removal was observed with 0.25g biosorbent dosage (64%). Increment of electrostatic relationship at high biomass fixation could inhibit DMP molecule absorption. DMP molecules in the solution will enter the intracellular part at a low biomass dosage, thereby increasing the concentration gradient of the DMP molecule. It can be said that the capacity of biosorption is improved by increasing the intercellular distance (low biosorbent dosage) (Mahmoud et al., 2016). It was also observed, that increase in biosorption capacity with decreasing biosorbent dose and increase in percentage dye removal with increasing biosorbent dosage when Saccharomyces cerevisiae was used to decolorize certain reactive dye from aqueous solution(Kumari et al. 2007) another study also revealed similar results when S. cerevisiae and R. nigricans was used to adsorb reactive green dye.

Adsorption Isotherms

The relevance of our experimental data for different isotherm models, namely Langmuir, Freundish, and Temkin model, were tested and the results were given in Table (1). The adsorption equilibrium was characterization adsorption equilibrium was characterize by Langmuir, Freundish, and Temkin model.

Langmuir Model

For equilibrium analysis, this is the most commonly used isotherm model (Dada et al. 2012).The model relies on the premise that adsorption occurs on a single layer of the uniform surface (homogeneous of limiting destinations equitably transmitted over the adsorbent's surface, i.e. the adsorbent's surface, i.e. There is a similar biosorption partiality in limiting locations and there is no correlation between the adsorbed molecules and biosorbent free sites. This implies that the active sites are all energetically equal. The model is given a

$${\text{q}}_{\text{e}}=\frac{{\text{q}}_{\text{m}}{\text{b}\text{C}}_{\text{e}}}{1+\text{b}{\text{C}}_{\text{e}}} \left(4\right)$$

If the equation changes into a linear form, it is expressed as

$\frac{1}{{\text{q}}_{\text{e}}}$ =$\frac{1}{\text{b}{\text{q}}_{\text{m}}}\frac{1}{{\text{C}}_{\text{e}}}$+$\frac{1}{{\text{q}}_{\text{m}}} \left(5\right)$

C_e= the equilibrium concentration of adsorbate (µg/ml)

q_{e =} greatest monolayer capacity of sorption (mg/g)

b = Langmuir isotherm constant (L/mg)

Therefore, q_m or Q⁰ (highest adsorption capacity) values of biosorbent and b (adsorption constant) are determined from a slope of 1/q_eq and 1/c_eq respectively. The significant attribute of the isotherm of Langmuir is revealed as RL (a constant without dimension), referred to as the factor of separation. RL can be calculated using the following equation, expressed as

R_L=$\frac{1}{1+\text{b}{\text{C}}_{0}} \left(6\right)$

The RL value indicates that the isothermal form is irreversible when (RL = 0), favorable when (0 ˂ RL ˃), liner when (RL = 1) or unfavorable (RL ˃).

Table 1

Parameter value of Langmuir, Freundlich, and Temkin Isotherm for adsorption of Dimethyl phthalate on silver nanoparticle-b on yeast (YB-Agapes).
Isotherm model	Parameters	Temperature (⁰C)
		30	40	50
Langmuir	Q^O (mg/g)	360	746	924
	B (L/m g)	0.014	0.070	0.055
	R_L^*	0.0053	0.0016	0.0021
	R²	0.9685	0.9156	0.9918
Freundlich	K_F (mg/g)	56.46	160.20	4.46
	1/n	0.2828	0.2483	9.0468
	N	3.54	4.03	0.1105
	R²	0.9578	0.9067	0.9871
Temkin	A_T(L/mg)	382.71	760	1064.02
	b_T	12.89	4.13	0.04
	B	195.43	630.09	998.55
	R²	0.9761	0.9736	0.5605

The Regression coefficient (R²) of Langmuir model for all the temperatures are closer to 1 and higher than Freundlich model. Also, the monolayer maximum adsorption limit estimated from Langmuir for 40^o C and 50^oC are 924 and 746 mg/g respectively. The closeness of these values to experimental data (904 and 694mg/g) for both 40 and 50^oc suggest good application of Langmuir model for his experiment. Likewise, the R_L of Dimethyl phthalate adsorption which ranges from (0.0014 and 0.0053) is a good indication that the biosorption of Dimethyl Phthalate onto YB-AgNPs is favorable.

Freundlich Isotherm

The Freundlich isotherm model is often used to represent a heterogeneous surface's adsorption characteristic; the isotherm is thus derived to model multi-layer adsorption (Dada et al. 2012).The actual linear formula initiated by Freundlich is defined as:

$${{\text{q}}_{\text{e}}={\text{K}}_{\text{F}}\text{C}}_{\text{e}}^{\frac{1}{\text{n}}} \left(7\right)$$

Linearizing the equation, it gives

$\text{l}\text{n}{\text{q}}_{\text{e}}$=$\text{l}\text{n}{\text{K}}_{\text{F}}+\frac{1}{\text{n}}\text{ln}{\text{C}}_{\text{e}} \left(8\right)$

Where K_F = Freundlich isotherm steady (mg/g); n = adsorption force; C_e= Concentration of adsorbate (mg/L); q_e is the measurement of sorbate adsorbed per gram of adsorbent at balance (mg/g); K_f and 1/n can be computed from the plot of Inq_eq against Inc_eq. The value of 1/n according to the isotherm is between 0 and 1 for the biosorption to be consider effective. It was observed from the data Table 1, the adsorption process can not fit well to freundlich model as R² parameters are lower compared to Langmuir isotherm. And also the N value exceeds 1 except for 50⁰C.

The nature of adsorption result observed can be consider monolayer because Q⁰˃K_f for all the result in the four temperature analyzed. (Table 1).

Temkin Isotherm

The relation between the adsorbate and the adsorbent is specifically evaluated by this isotherm. The model acceptance (temperature capacity) of all atoms in the layer will decrease linearly by neglecting very low and extensive concentration values as compared to logarithmic with Scope. As indicated in the case, its deduction is defined by a uniform transmission of limiting energies (up to some of the most extreme limiting energy) by plotting the volume sorbed q_e against ln C_e and measuring the constants from the slope and intercept. The following equation provides the mode

${\text{q}}_{\text{e}}$ =$\frac{\text{R}\text{T}}{\text{b}}\text{ln}{(\text{A}}_{\text{T}}{\text{C}}_{\text{e}}\left) \right(9)$

By linearizing the equation, we have

${\text{q}}_{\text{e}}$ = $\frac{\text{R}\text{T}}{{\text{b}}_{\text{T}}}\text{ln}{\text{A}}_{\text{T}}$+ ($\frac{\text{R}\text{T}}{\text{b}}\left)\text{l}\text{n}{\text{C}}_{\text{e}} \right(10)$

B =$\frac{\text{R}\text{T}}{{\text{b}}_{\text{T}}} \left(11\right)$

${\text{q}}_{\text{e}}$=B${\text{l}\text{n}\text{A}}_{\text{T}}$+B${\text{l}\text{n}\text{C}}_{\text{e}} \left(12\right)$

A_{T =} Temkin isotherm harmony restricting consistent (L/g)

B_T = Temkin isotherm steady

R = Gas steady constant (8.314J/mol/k)

T = Temperature at 298K

B = Constant identified with warmth of sorption (J/mol)

It was observed from the result from the above table (A_T = 0.04–12.89 L/g, B = 195.43–998.55 J/mol and R² = 0.5605–0.9761) is a sign that adsorption process was good for all temperature (Dada et al. 2012).

Kinetic Studies

What governs the kinetic adsorption is the rate at which DMP molecules are exchanged for the surface of the adsorbent from the mass solution. It gives an understanding of the possible sorption mechanism, and the time it takes for the sorbate particle to remove on the sorbent's surface.

Pseudo First Order

As far as adsorption capability is concerned, this model is one of the first known to illustrate the rate of adsorption. It is based on the premise that the rate of adsorption is proportional to the limitations on the quantity of free areas (Yousefi et al. 2016) given by;

${\text{ln}(\text{q}}_{\text{e}}$-${\text{q}}_{\text{t}})$=${\text{ln}\text{q}}_{\text{e}}-{\text{k}}_{1} \text{t} \left(13\right)$

Where q_e and q_t are the equilibrium and time adsorbent adsorption limit; t (mg/g), K1 is the constant pseudo-first order rate (min-1). The of kinetic constants value are measured from the slope and intercept of the plotted graph ln (q_e -qt) against t. The relationship coefficient values (R2) are used as a measure for the quality of the fit for the trial. In addition to the relationship coefficient values (R2), the estimates of computed q_e and K₁ are given in Table 2 in this investigation. The low q_e (calc) and even the low R2 values imply that the model is not appropriate to this method compared to the q_e (exp) values.

Pseudo Second Order Model

Pseudo-second order model relies on premise that adsorption rate corresponds to the quantity square of empty binding sites (McKay et al. 1999.). In linear terms, the model is depicted as

$\frac{\text{t}}{{\text{q}}_{\text{t}}}$=$\frac{1}{{\text{k}\text{q}}_{\text{e}}2}$ + $\frac{1}{{\text{q}}_{\text{e}} \text{t}} \left(14\right)$

Therefore: K is pseudo-second order rate constant (min^− 1). The slope and intercept of t/q_t against t plot gives the individual estimate of q_e and K (Table 2). The expression h (mg/g min) that defines the initial sorption rate can be determined by:

h=${\text{k}\text{q}}_{\text{e}}2 \left(15\right)$

The q_i (calc) values are as similar as the q_e (exp) values for the adsorbent from Table 2. In addition, the coefficients obtained for this model in this analysis are higher (> 0.99) for temperatures than all other examined models indicating that second order kinetic kinetic will positively represent the procedure.

Table 2

Kinetic parameters values of Dimethylphthalate biosorption onto Yeast Based Silver Nanoparticle at different temperatures and pH
Model Parameters				pH
	30	40	50	3	4	5	6
Pseudo First order
qe (mg/g)	341.72	1339.97	910.51	471.54	258.01	368.7	343.8
K₁(min-1)	0.0802	0.1997	0.0802	0.3078	0.2354	0.15	0.0112
R²	0.9992	0.9344	0.7964	0.8213	0.9325	1	1
Pseudo Second order
Q_e (mg/g)	416.67	1833.3	1666.67	333.33	270.27	384.62	344.83
K₂(g/mg.min)	0.0020	0.0012	0.00026	0.0012	0.0013	0.0013	0.02
R²	0.982	0.9796	0.9807	0.9975	0.9433	0.993	1
Weber-Morris
Kid (mg.min^0.5)	47.55	97.302	167.95	38.307	31.311	46.063	61.514
C	22.068	61.217	30.989	89.052	94.283	104.98	93.759
R²	0.9115	0.8815	0.9882	0.7088	0.6252	0.6483	0.6593

Weber Morris Kinetic Model

As indicated by this model, if intraparticle dispersion occurs in the entire adsorption system, the plot of q_t versus t¹/2 is said to be linear (C = 0) and the dissemination intraparticle is one of the key rate constraining phase of the method, in any case, in a case where the line did not cross the root (C ≠ 0) both intraparticle dispersion and limit phase impact both occur in the adsorption process. The model can be related to the straight formula underneath.

${ \text{q}}_{\text{t}}= {\text{k}}_{\text{d}}{\text{t}}^{1/2}$+${\text{C}}^{1/2} \left(16\right)$

Where k_d (mg/g.min^1/2) is a constant rate of Weber Morris model and C is intercepte, it can be seen from the table that C ≠ 0 indicates that the biosorption of DMP on YB-AgNPs was influenced by both intraparticle diffusion and boundary layer and also shows that the model of diffusion intraparticle was not the major rate controlling phase.

Adsorption Thermodynamics

Thermodynamic experiments were performed to establish the adsorption mechanism of DMP on YB-AgNPs at various temperatures (303-323k). Using change in free energy (ΔG), change in enthalpy (ΔH) and change in entropy (ΔS) given by the equations below, the thermodynamic parameters were calculated.

ΔG = -RT$\text{ ln}{\text{K}}_{\text{C}} \left(17\right)$

The change in enthalpy (ΔH) and change in entropy (ΔS) parameters were calculated from the equation below

$\text{ln}{\text{K}}_{\text{C}}$ = $\frac{{\Delta }\text{S}}{\text{R}}-\frac{{\Delta }\text{H}}{\text{R}\text{T}} \left(18\right)$

Where ΔG is the Gibbs free energy change,

T: temperature (K), K_C (q_e/C_e) is called constant of equilibrium.

ΔH and ΔS of biosorption method were observed from the slope and the intercept of the plot of In K_C versus 1/T, respectively. The value of ΔH, ΔS, and ΔG were determined using the equations above.

Table 3

Thermodynamic parameters for Adsorption of Dimethyl phthalate on Yeast Based Silver Nanoparticle.
T(K)	ΔG^o (kJ/mol)	ΔS^o (J/mol k)	ΔH^o (KJ/mol
303	-1.04	244.3	74.9
313	-1.91
323	-3.70

Table 3, provides the values of these parameters. It implies that the shift in enthalpy ΔH is positive (endothermic) due to the rise in adsorption for consecutive temperature increases. The negative values of ΔG have shown that sorption is thermodynamically viable and spontaneous in nature. The positive value of ΔS demonstrates the increased randomness at the solid-solution interface during the fixation of the ion at the active locations of the sorbent (Esfandian et al. 2016). According to the literature, physisorption is considered to be G values between 0 and-20 KJ/mol while chemisorption is considered to be chemisorption values between − 80 and − 400 KJ/mol (Özcan et al. 2014). ΔG calculated or YB-AgNPs at different temperatures are between 0 and − 20 which indicates the physical adsorption process.

The results obtained in this research study clearly show the promise of dried YB-AgNPs, as an inexpensive material and a potential biosorbent for pharmaceutical waste disposal. The results clearly presented in this study show the efficacy of dried YB-AgNPs biosorbent in the eliminating of dimethyl phthalate from aqueous solutions in this analysis using biosorbent derived from commercially purchased yeast with the chemically produced silver nanoparticle. Impact of various parameters, namely the adsorbent dosage, solution pH, temperature, concentration of dimethyl phthalate and contact time, were studied. At acidic pH, the highest dimethyl phthalate biosorption was found to take place. The amount of adsorption increased as the solution pH increased from 3 to 5 and remained almost constant at higher pH 5, but at pH 6, which can be assumed to be desorption, there was a small decrease. This may also be attributed to the negative surface charge of YB-AgNPs over a wide pH range. For the biosorption of the dimethyl phthalate from an aqueous solution onto a dried YB-AgNPs biosorbent, equilibrium and kinetic tests were performed. And the parameters of the characteristics were calculated for each isothermal and associated relationship coefficient. In this analysis, the Langmuir isotherm model is ideally suited to Yeast Based Silver Nanoparticle for the biosorption of Dimethyl phthalate. This shows the potential of biosorption for the appropriateness of the Dimethyl single layer coverage on the biosorbent surface. The biosorption kinetic model was also used to analyze the results obtained and it was found that the biosorption based on the experiment data analyzed in the paper follows the biosorbent pseudo-second-order model. Thermodynamic study of the analysis data indicated that the method was random and feasible. It also means that adsorption was regulated by the Physisorption process. It can therefore be inferred that it is very possible to clean up environmental contaminants using natural resources such as low-cost and efficient YB-AgNPs without posing a hazard to secondary pollutants.

Funding

The authors declare that The Biotechnology Research Centre and Environmental Laboratory of Cyprus International University TRNC (CIU) assisted in technical support and research funding during the preparation of this manuscript.

Author Contributions

All authors contributed to the study conception and design. Material preparation, data collection and analysis were performed by Temitayo Omoyeni, and Hatice Erkurt. The first draft of the manuscript was written by Temitayo Omoyeni and Hatice Erkurt commented on previous versions of the manuscript. All authors read and approved the final manuscript.

Awad, F. and Erkurt, H.A., 2014. Biosorption of lead (II) and copper (II) by pinus resinosa: modeling and mechanism. Fresenius Environmental Bulletin, 23(2A), pp.540-549.
Chekin, F. and Ghasemi, S., 2014. Silver nanoparticles prepared in presence of ascorbic acid and gelatin, and their electrocatalytic application. Bulletin of Materials Science, 37(6), pp.1433-1437, https://doi.org/10.1007/s12034-014-0093-3.
Dada, A. O., Olalekan, A. P., Olatunya, A. M., & Dada, O. J. I. J. C. (2012). Langmuir, Freundlich, Temkin and Dubinin–Radushkevich isotherms studies of equilibrium sorption of Zn2+ unto phosphoric acid modified rice husk. IOSR Journal of Applied Chemistry, 3(1), 38-45, https://doi.org/10.9790/5736-0313845.
Debs, K.B., Cardona, D.S., da Silva, H.D., Nassar, N.N., Carrilho, E.N., Haddad, P.S. and Labuto, G., 2019. Oil spill cleanup employing magnetite nanoparticles and yeast-based magnetic bionanocomposite. Journal of environmental management, 230, pp.405-412, DOI:10.1016/j.jenvman.2018.09.094.
Esfandian, H., Samadi-Maybodi, A., Parvini, M. and Khoshandam, B., 2016. Development of a novel method for the removal of diazinon pesticide from aqueous solution and modeling by artificial neural networks (ANN). Journal of industrial and engineering chemistry, 35, pp.295-308, https://doi.org/10.1016/j.jiec.2016.01.011.

Fomina, M. and Gadd, G.M., 2014. Biosorption: current perspectives on concept, definition and application. Bioresource technology, 160, pp.3-14, DOI: 10.1016/j.biortech.2013.12.102.
Jabesa, A. and Ghosh, P., 2016. Removal of diethyl phthalate from water by ozone microbubbles in a pilot plant. Journal of environmental management, 180, pp.476-484, https://doi.org/10.1016/j.jenvman.2016.05.072.
Julinová, M. and Slavík, R., 2012. Removal of phthalates from aqueous solution by different adsorbents: a short review. Journal of environmental management, 94(1), pp.13-24, https://doi.org/10.1016/j.jenvman.2011.09.006.
Kumar, K. Y., Raj, T. V., Archana, S., Prasad, S. B., Olivera, S., & Muralidhara, H. B. (2016). SnO2 nanoparticles as effective adsorbents for the removal of cadmium and lead from aqueous solution: adsorption mechanism and kinetic studies. Journal of Water Process Engineering, 13, 44-52, https://doi.org/10.1016/j.jwpe.2016.07.007.
Kumari, K. and Abraham, T.E., 2007. Biosorption of anionic textile dyes by nonviable biomass of fungi and yeast. Bioresource Technology, 98(9), pp.1704-1710, http://dx.doi.org/10.1016/j.biortech.2006.07.030.
Mahmoud, A. E. D., Fawzy, M., & Radwan, A. (2016). Optimization of Cadmium (CD2+) removal from aqueous solutions by novel biosorbent. International journal of phytoremediation, 18(6), 619-625, https://doi.org/10.1080/15226514.2015.1086305.
McKay, G., Ho, Y.S. and Ng, J.C.Y., 1999. Biosorption of copper from waste waters: a review. Separation and Purification Methods, 28(1), pp.87-125, https://doi.org/10.1080/03602549909351645.
Osman, B., Özer, E.T., Demirbel, E., Güçer, Ş. and Beşirli, N., 2013. Synthesis and characterization of L-tryptophan containing microbeads for removal of dimethyl phthalate from aqueous phase. Separation and Purification Technology, 109, pp.40-47, https://doi.org/10.1016/j.seppur.2013.02.025.
Özcan, A., Öncü, E.M. and Özcan, A.S., 2006. Kinetics, isotherm and thermodynamic studies of adsorption of Acid Blue 193 from aqueous solutions onto natural sepiolite. Colloids and surfaces A: Physicochemical and engineering aspects, 277(1-3), pp.90-97, https://doi.org/10.1016/j.colsurfa.2005.11.017.
Parada, J., Rubilar, O., Diez, M.C., Cea, M., da Silva, A.S.A., Rodríguez-Rodríguez, C.E. and Tortella, G.R., 2019. Combined pollution of copper nanoparticles and atrazine in soil: effects on dissipation of the pesticide and on microbiological community profiles. Journal of hazardous materials, 361, pp.228-236, https://doi.org/10.1016/j.jhazmat.2018.08.042
Roslev, P., Vorkamp, K., Aarup, J., Frederiksen, K. and Nielsen, P.H., 2007. Degradation of phthalate esters in an activated sludge wastewater treatment plant. Water research, 41(5), pp.969-976, https://doi.org/doi:10.1016/j.watres.2006.11.049
Soni, M., Sharma, A.K., Srivastava, J.K. and Yadav, J.S., 2012. Adsorptive removal of methylene blue dye from an aqueous solution using water hyacinth root powder as a low cost adsorbent. International Journal of Chemical Sciences and Applications, 3(3), pp.338-345.
Srirangam, G.M. and Rao, K.P., 2017. Synthesis and charcterization of silver nanoparticles from the leaf extract of malachra capitata (L.). Rasayan Journal of Chemistry, 10(1), pp.46-53, http://dx.doi.org/10.7324/RJC.2017.1011548
Tijani, J.O., Fatoba, O.O., Babajide, O.O. and Petrik, L.F., 2016. Pharmaceuticals, endocrine disruptors, personal care products, nanomaterials and perfluorinated pollutants: a review. Environmental Chemistry Letters, 14(1), pp.27-49, DOI: 10.1007/s10311-015-0537-z.
Vanaja, M., Gnanajobitha, G., Paulkumar, K., Rajeshkumar, S., Malarkodi, C. and Annadurai, G., 2013. Phytosynthesis of silver nanoparticles by Cissus quadrangularis: influence of physicochemical factors. Journal of Nanostructure in Chemistry, 3(1), pp.1-8, doi: 10.1186/2193-8865-3-1.
Wang, H., Li, H., Song, Q., Gao, L. and Wang, N., 2017. Adsorption of Phthalates on Municipal Activated Sludge. Journal of Chemistry, 2017, https://doi.org/10.1155/2017/4160929
Wang, J. and Chen, C., 2006. Biosorption of heavy metals by Saccharomyces cerevisiae: a review. Biotechnology advances, 24(5), pp.427-451, https://doi.org/10.1155/2008/568717.
Wong, Y. C., Szeto, Y. S., Cheung, W. H., & McKay, G. (2004). Pseudo‐first‐order kinetic studies of the sorption of acid dyes onto chitosan. Journal of Applied Polymer Science, 92(3), 1633-1645, doi: 10.3390/ma6115131.
Yousefi, E., Sharifzadeh, M., & Esfandian, H. (2016). Removal of dimethyl phthalate from aqueous solution by synthetic modified nano zeolite using Cu2O nanoparticles. International Journal of Engineering, 29(9), 1198-1207, https://doi.org/10.1155/2015/364763.
Yuan, B., Li, X., Li, K., & Chen, W. (2011). Degradation of dimethyl phthalate (DMP) in aqueous solution by UV/Si–FeOOH/H2O2. Colloids and Surfaces A: Physicochemical and Engineering Aspects, 379(1-3), 157-162, https://doi.org/10.1016/j.colsurfa.2010.11.039.
Zhang, L., Liu, X., Wang, W., Li, Y., Sun, P., Shang, S. and Jiang, Q., 2018. Characteristics and mechanism of lead adsorption from aqueous solutions by oil crops straw-derived biochar. Transactions of the Chinese Society of Agricultural Engineering, 34(7), pp.218-226, DOI:10.11975/j.issn.1002-6819.2018.07.028

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Biosorption of Dimethyl Phthalate From Aqueous Solution Using Yeast-based Silver Nanoparticle

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1. Introduction

2 Materials And Methods

2.1 Materials

3 Result And Discussion

3.1 Characterization of the Biosorbent

4. Conclusions

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