(2024) 18:144
Dardeer et al. BMC Chemistry
https://doi.org/10.1186/s13065-024-01244-w

BMC Chemistry

RESEARCH

Open Access

Promising superabsorbent hydrogel basedon carboxymethyl cellulose and polyacrylic acid:synthesis, characterization, and applications
in fertilizer engineering
Hemat M. Dardeer1, Ahmed N. Gad2 and Mohamed Y. Mahgoub1*

Abstract
The combination of hydrogel and fertilizer as slow release fertilizer hydrogel (SRFH) has become one of the mostpromising materials to overcome the shortcomings of conventional fertilizer by decreasing fertilizer loss rate, supplying nutrients sustainably, and lowering the frequency of irrigation. The hydrogel based on carboxymethyl cellulose (CMC) and polyacrylic acid (PAA) (CMC/PAA) was synthesized. All materials, Vinasse, hydrogel (CMC/PAA)
and (Vinasse/CMC-PAA) were characterized by FTIR, XRD, and SEM. The formed hydrogel was applied to control
the salinity of Vinasse to use it as a cheap and economical fertilizer. The results showed that using the prepared hydrogel with Vinasse (V/CMC-PAA) as a slow-release organic fertilizer decreased the EC value through the first six hours
from 1.77 to 0.35 mmohs/cm. Also, using V/CMC-PAA can control and keep the potassium as fertilizer for 50 days. The
productivity per feddan from the sugar cane crop increased by about 15%, and the number of irrigations decreased
from 5 to 4 times.
Keywords Fertilizer, Hydrogel, Vinasse, Sugar cane, Electrical conductivity, SEM
Introduction
The growing need for environmentally sustainable materials is a critical issue in the development of bio-based
products at present [1–3]. The most prevalent challenges
encountered in the agricultural sector include elevatedsoil porosity, excessive water irrigation, and inadequate
fertilizer retention. Thus, the majority of conventional
fertilizers are discharged into the environment via dissolution or volatilization, rendering them devoid of any*Correspondence:
Mohamed Y. Mahgoub
m.mahgoub2013@gmail.com
1
Chemistry Department, Faculty of Science, South Valley University,
Qena 83523, Egypt
2
Research and Development Center, Egyptian Sugar & Integrated
Industries Company ‘ESIIC’, Cairo, Egypt

advantageous effects on plants [4, 5]. The depletion offertilizer hinders the plant’s acquisition of adequate
nutrients, in addition to causing environmental harm andescalating process expenses [6]. Active nutrient-containing delayed or controlled release fertilizers have been thesubject of numerous studies in recent years [7]. Vinasse isa liquid byproduct that is generated during the bioethanol production process. Vinasse yields nine to fourteen
liters per liter of ethanol [8]. Vinasse is a prospective
bio-raw material that is utilized as fertilizer due to its
nutrient composition, including nitrogen, phosphorus,and potassium, all of which have the capacity to enhance
the growth of agricultural crops [9, 10]. The applicationof vinasse directly to the soil results in numerous environmental issues due to its elevated levels of electricalconductivity (EC), low pH, and excessive fertilization of
the soil [11, 12]. Efforts are being made to supplement© The Author(s) 2024. Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which
permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to theoriginal author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images orother third party material in this article are included in the article’s Creative Commons licence, unless indicated otherwise in a credit line
to the material. If material is not included in the article’s Creative Commons licence and your intended use is not permitted by statutory
regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of thislicence, visit http://​creat​iveco​mmons.​org/​licen​ses/​by/4.​0/. The Creative Commons Public Domain Dedication waiver (http://​creat​iveco​
mmons.​org/​publi​cdoma​in/​zero/1.​0/) applies to the data made available in this article, unless otherwise stated in a credit line to the data.

Dardeer et al. BMC Chemistry(2024) 18:144

Page 2 of 13

soil fertility with Vinasse and a byproduct of sugar canejuice processing (filter cake), which is utilized to enhance
aggregate stability and average weighted diameter. Filter
cake, which has a high moisture content, is an abundantsource of phosphorus and organic matter [13]. However,this endeavor falls short of resolving every Vinasse issue.
Vinasse must be utilized in conjunction with controlled
nutrient release to the soil for the nutrients to be utilized
effectively. Superabsorbent polymers (SAPs) are natural or synthetic cross-linked polyelectrolyte polymericmaterials with the capacity to absorb, store, and gradually release significant quantities of water and nutrients
via osmotic pressure [5, 6]. As a result, these polymers
are implemented as slow release fertilizer hydrogels(SRFHs) in agricultural fields with the dual purpose ofenhancing soil physical properties and reducing water
irrigation rates, thereby increasing crop productivity[14, 15]. The integration of fertilizer into hydrogel resultsin the formation of SRFH, an organic compound thatenhances soil water retention [16], reduces plant mortality, and promotes plant growth [17, 18]. Acrylic acid
(PAA) or acrylate derived from synthetic SRFHs is moreenvironmentally friendly than aldehyde and acrylamide
derivatives [19, 20]. This is due to the fact that the latter
undergoes numerous side reactions that produce noxious
residues. Carboxymethyl cellulose (CMC) is a cellulose
ether derivative [21–23] in which sodium carboxymethylgroups (–CH2COONa) replace a portion of the hydroxyl
groups of the glucopyranose units. The food industry,
pharmaceuticals, adhesives, ceramics, textiles, cosmetics,
and detergents are a few of the many industries that utilize CMC [24, 25]. The carboxymethyl functional groups
incorporated along the polymer chain enhanced its watersolubility and reactivity. In this paper, we attempt tosynthesize a new natural and synthetic polymer CMC/
PAA-based combined hydrogel in order to maximize thebenefits of each variety. By encapsulating vinasse withthis new hydrogel, its release during irrigation can be
regulated, resulting in the formation of a slow-release fertilizer that effectively reduces the detrimental effects ofvinasse’s high salinity when applied as a fertilizer to sugar
cane crops for the first time. CMC/PAA is implemented
in order to enhance the physical characteristics, reduce
the rate of release, and mitigate the adverse impacts ofvinasse on the environment and soil.

Aldrich, Milwaukee, Wisconsin, USA. Vinasse is supplied from a local factory (Abo-Korkass-ESIIC) in Egypt.
All chemicals were used as received without additional
purification.

Materials and methods
Materials

Synthesis of carboxymethyl cellulose sodium salt (CMC)
from bleached bagasse pulp

CMC-Na was prepared from bleached bagasse pulp supplied by the Qena Company of Paper Industry, Egypt.
Polyacrylic acid, NaOH, sodium monoacetate, triethanolamine (TEA), and citric acid were purchased from
Merck Co., Germany; methanol was supplied from

The procedure applied for preparing CMC is adapted asfollows: first, 15 mL of sodium hydroxide (NaOH 30%)
was added to 4.5 g of cellulose (bleached bagasse pulp),
then 140 ml isopropanol was added to the mixture withvigorous stirring for 1 h. After that, a solution of 5.4 g

Instruments
Fourier‑transformation infrared (FTIR)

Fourier transform infrared FT-IR transmission spectraof all present samples were examined in the common
wavenumber range of 400 to 4000 ­cm−1 via FT-IR Nicolet
6700 spectrometer. The samples’ powder was well groundwith high purity KBr and compressed into small pellets.
X‑ray diffraction (XRD)

The pulverized X-ray diffraction (PXRD) patterns of thehydrogel, Vinasse before and after coating were obtainedusing an advanced diffractometer instrument (Bruker
D8, Germany), supported by CuKα X-ray source with awavelength of 1.5406 Å. X-ray patterns were investigatedin the 2θ range from 5° to 80° with a scanning rate 2° permin.
Scanning electron microscope (SEM)

The surface morphology structure of Vinasse and the
prepared hydrogel (CMC/PAA) were measured by scanning electron microscopy that has a type of JSM-5500-Japan apparatus, was used at magnification 10,000 times
with an excitation voltage of 15 kV.
Analytical measurements

Vinasse was characterized using proximate and ultimate
analysis (LECO CHNS 932 Elemental Analyzer). Vinasse
was filled into spectrophotometer cuvettes of known
volume and weight. The density was detected by calculating the weight difference made after the vibration was
well placed. Potassium was determined using flamephotometer, PFP 7, Jenway, UK. The Electrical conductivity
was measured using conductivity meter, 4510, Jenway,
UK.The efficiency of the prepared CMC/PAA as (SROFH)
was followed by leaching test, where the concentration ofpotassium in the leached water from (SROFH-V/CMCPAA) sample was determined compared with that fromvinasse sample itself, using Flam photometer. The electrical conductivity for the two samples was measured using
EC-conductivity meter.

Dardeer et al. BMC Chemistry(2024) 18:144

sodium monochloroacetate was added with continuous
stirring for 2 h at 60 °C. The solid residual was filtered
off and washed with 70% three times, then dried at
60 °C. The degree of substitution of produced CMC wasdetermined according to the ASTM D1439-03 T standard method and was found to be 0.75.
Synthesis of hydrogel (PAA/CMC)

Aqueous solution of CMC (1.2 wt%), containing 0.10
wt% citric acid as a crosslinker, and aqueous dispersion of PAA (0.8 wt%) were prepared in distilled water.
Then, CMC solution was poured into PAA solution
with stirring till the pH becomes acidic (pH ̴ 5), which
is neutralized with some droplets of triethanolamine
TEA. The clear hydrogel was obtained. After that, thegel was placed in a petri dish and dried at 50 °C for further analysis.
Capsulation of vinasse on hydrogel (V/PAA/CMC)

Vinasse is the final liquid waste left over from the distillation industry of ethyl alcohol. Its importance as afertilizer because of its highly content of potassium andorganic matter. On the other hand, the using of Vinasse
as fertilizer is limited due to the increased electricalconductivity (EC) of up to 25 mmoh/cm for concentrated Vinasse. At the same time, diluting Vinasse tolower the EC leads to the loss a large amount of potassium through leaching. Therefore, in this study, we areinterested in controlling EC through slow fertilizer dissociation. The synthesized slow release organic fertilizer hydrogel SROFH (PAA/ CMC) uses for coating ofVinasse and improve its physical properties. The product was evaluated as a fertilizer and tracked the change
in EC compared to Vinasse as a control. Generally, slow
release fertilizer SRFH can be classified according to
the preparation methods to two main types, matrix andcoated. The matrix hydrogel can be prepared in situ
method in which fertilizer present in liquid form [26],also, can be prepared with two steps in this approach
the solid hydrogel is immersed fertilizer in liquid form
then the swollen hydrogel is dried. The second class iscoated method. In this paper we use a simple methodology for the coating method. In which Vinasse was usedin solid form and the prepared hydrogel used in liquid
form to be obtained good and economically SROFH (V/
CMC-PAA). In this route (10 g) of the prepared hydrogel was sprayed on (100 g) of Vinasse powder with goodstirring till completely wetting. After that the mixture
was dried at room temperature to form capsulatedparticles.

Page 3 of 13

Field experiment

For cane sugar crops, the prepared V/CMC-PAA andfine dry soil were mixed in a 1:10 ratio and applied to thetransplant before planting. To obtain the greatest results,
the V/CMC-PAA mixture should be close to routes. Eachtransplant utilizes 2 g/m2 of a nursery bed mix of hydrogel uniformly in the top 2 inches of the nursery bed. In
pot culture, mix 3–5 g/kg of soil before planting. Whiletransplanting, mix 2 g of hydrogel per liter of water toprepare a free-flowing solution and allow it to settle forhalf an hour. Dip the roots of the plant in the solution andthen transplant in the field [27]. In this study, we apply
the experiment to two feddan plantings with cane sugar
crops. Vinasse was only used in one feddan (control), and
V/CMC-PAA was applied to the other feddan. In thisexperiment, 2 kg of hydrogel CMC/PAA have been used
to coat 60 kg of Vinasse per feddan, then mixed with thesoil in a 1:10 ratio. Twenty stalks of the two central raw ofeach crop were randomly harvested and weighed immediately. The quality control points of juice such as sugar,
reducing sugar, purity and P­ 2O5 were determined according to ICUMSA method and thus the theoretical productivity per feddan was evaluated for each treatment. All
the experimental processes can be summarized in Fig. 1.

Results and discussion
Formation of CMC‑PAA

The chemical method for the preparation of CMC/PAA
as a slow-release organic fertilizer hydrogel for vinasse
involves the formation of hydrogen bonds between theactive groups in CMC (COOH-OH) and the functiongroups in polyacrylic acid PAA (COOH). Scheme 1 indicates the synthetic method for the preparation of hydrogel and also explains the mechanism of crosslinking thattakes place between citric acid (linker) and CMC and
PAA [28, 29]. There are three types of crosslinking that
affect the formation of the hydrogel CMC/PAA. Firstly,
the ester formation between the hydroxyl groups of CMC
and the carboxylic groups of citric acid. Secondly, the formation of hydrogen bonds between the hydroxyl groupsof CMC, the carboxyl group of the linker (citric acid), andthe carboxyl groups of polyacrylic acid [30]. The last typeof crosslinking is the electrostatic attraction between
negative and positive charges [31]. The formed hydrogel is very clear and has excellent homogeny. The prepared CMC/PAA is considered combined SAH because
it contains natural polymer (CMC) with synthetic polymer (PAA). The CMC is grafted with PAA to improve its
biodegradability and mechanical properties. The presence of CMC as a natural polymer can reduce the production costs of the hydrogel and the negative impacts
on the environment. Furthermore, incorporating natural

Dardeer et al. BMC Chemistry(2024) 18:144

Page 4 of 13

Fig. 1 The graphic diagram for the preparation of V/CMC-PAA and its application in sugar cane crops

Scheme 1 Representation of the synthetic method for the preparation of hydrogel CMC/PAA and the crosslinked hydrogel network

polymer with synthetic polymer lead to increase water
absorbency and plant growth performance [16].
Characterization
FTIR analysis

FTIR spectra is a very important technique that is used
to detect the chemical structure of target compounds(Fig. 1) displays an informative comparison between

FTIR transmission spectra of pure CMC-Na and the
newly prepared slow release fertilizer hydrogel (PAA/
CMC). The FTIR spectrum of CMC-Na shows many
distinctive peaks of carboxymethyl cellulose structure.
The broadband at 3385 ­cm−1 is ascribed to stretchingvibrations of OH groups as well as inter-intra molecularhydrogen bonding of CMC molecules. The characteristic band of asymmetric stretching vibration of aliphatic

Dardeer et al. BMC Chemistry(2024) 18:144

Page 5 of 13

Vinasse-CMC-PAA
CMC-PAA
VinasseTransmittance %

100

1734

2864

80

1036

3373
2925

60

1450

40

1042

1674

2920

1080

3354

20

1045
1660

3362

1459

1092

0
4000

3500

3000

Fig. 2 The FTIR spectra of pure CMC and CMC/PAA

2500 2000 1500
Wavenumber, cm-1

1000

500

Fig. 3 The FTIR spectra of Vinasse, CMC/PAA and V/CMC-PAA

Table 1 The difference in the intensity of CMC and CMC/PAA
hydrogel
Functional group

ν[OH] symmetric

Wavenumber ­(cm−1)

Changes

Table 2 The difference in the intensity of PAA and CMC/PAA
hydrogel

CMC

CMC/PAAΔδ

Functional group3385.423373.85− 11.57

Wavenumber ­(cm−1)

ChangesPAA

Δδ

CMC/PAAν[CH-aliphatic]

2861.842864.73+ 2.89

ν[OH] symmetric3390.24

3373.85− 16.39

ν[C=O]

1730.791734.65+ 3.86

ν[CH-aliphatic]

2890.772864.73− 26.04

ν[C–O–C]

1159.971160.93+ 0.96

ν[C=O]

1728.671734.65+ 5.98

ν[O–H] bending vibration

1030.761026.55− 4.21

ν[O–H] bending vibration

1031.721036.55+ 4.83

C–H were observed at 2861 ­cm−1 and two bands situatedat 1159 and 1730 ­cm−1 were associated to the asymmetric stretching vibration of the C–O–C glycoside bridge
and C=O groups. The FTIR spectrum of hydrogel (PAA/
CMC) indicates some significant changes in the frequencies of the prepared hydrogel. Such these changes for thehydroxyl groups were shifted toward lower wavenumber
at 3373 ­cm−1 and other characteristic transmission bandsof CH aliphatic, carbonyl groups and glycosidic groups
were shifted toward the higher wavenumber at 2864,
1734 and 1160 respectively, (Fig. 2, Table 1 showing thedifference in the frequencies of CMC and the obtained
CMC/PAA. (Fig. 3) demonstrates the comparison in the
FTIR spectra of the Vinasse before and after loading on
the prepared hydrogel (CMC/PAA). (Table 2) shows thechanges in the intensity of PAA and CMC/PAA hydrogel. The hydroxyl groups (OH) of pure PAA were shifted
toward lower wavenumber from 3390 to 3372 ­cm−1 andthe peak of CH aliphatic was shifted toward lower frequency at 2864 ­cm−1, carbonyl groups were shifted from1728 to 1734 ­cm−1 toward the higher wavenumber due tothe formation of Vanderwall forces and hydrogen bonds.
The chemical composition of Vinasse contains highly

concentrated biodegradable organic compounds suchas, residual sugar, ethanol, other metabolites resulting
from parallel fermentation pathway. The FTIR spectrumof Vinasse shows a wide band at 3354 ­cm−1 indicatesthe absorbed water content in addition to the hydroxyl
groups for residue sugar and organic acids in Vinasse[32]. Moreover, the bands at 1647 ­cm−1 are correlated to
C=C and strong peak at 1450 ­cm−1 indicates C–H groups[33]. The FTIR spectrum of Vinasse after loading on the
prepared hydrogel shows appearance of some significant
changes in the wavenumbers according to the loading
process. Such changes, the broadband at 3354 ­cm−1 inVinasse spectrum was found to shift towards the higher
wavenumber 3362 ­cm−1. Aliphatic C–H bands moved toappear at 2920 ­cm−1 towards the lower wavenumber. In
addition to the C=C and C–O were shifted towards thehigher wave number 1459 and 1092 ­cm−1. Table 3 indicates the difference in the intensity of Vinasse after loading on CMC-PAA hydrogel.
XRD analysis

X-ray diffraction technique is a good method to examine the crystalline structure nature of compounds. In

Dardeer et al. BMC Chemistry(2024) 18:144

Page 6 of 13

Table 3 The difference in the intensity of Vinasse and Vinasse/
CMC-PAA hydrogel
Functional group

Wavenumber ­(cm−1)

Changes

VinasseΔδ

V/CMC-PAA (HG)ν[OH] symmetric3354.233362.43+ 8.2

ν[CH-aliphatic]

2925.55

2920.56− 4.99ν[C=O]

1647.61

1660.22+ 12.61ν[C=C] symmetric

1450.671459.27+ 8.6

ν[C–O] symmetric1080.881092.34+ 11.46

ν[C–C]

1042.451045.28+ 2.83[34]. The appearance of such peaks can be explainedby the presence of free hydroxyl groups along the
backbone of CMC and formation of hydrogen bonds
between them [35]. While, the XRD pattern of the prepared hydrogel (CMC/PAA) shows that the peak at
53.3° of CMC was shifted to 52.6° and the peak became
more broadening and less intensity. This is due to theformation of new hydrogen bonding between the OH,
C=O groups in CMC chain and the other carboxylic
groups in PAA polymer. Also, the hydrogen bonds thatlink the CMC chains together decreased [36]. Thesechanges give good indication for the formation ofhydrogel (CMC/PAA). The XRD spectrum of Vinasse
has many sharp and intense peaks were observed at
28.1°, 29.2° and 40.5°. Furthermore, the XRD patternof Vinasse after coating with the hydrogel (CMC/PAA)
indicates presence of some changes in the intensityof the peaks. The peak at 29.2° was shifted to 2θ = 28°
and the intensity of its peak became sharper. The peakat 40.5° was became 40, also, a new peak appears at2θ = 25.5° with high intensity. These changes confirm
the capsulation of Vinasse by the prepared hydrogel.
This result depends on the presence of hydrophilichydrophilic interaction in addition to the formationof hydrogen bonding between the active groups in
Vinasse and the hydroxyl groups of the hydrogel CMC/
PAA. The crystalline order of these materials was V/
CMC-PAA > Vinasse > CMC/PAA > CMC. These results
were logical due to the fact that CMC/PAA have higher
crystalline.
SEM analyses

Fig. 4 XRD patterns of all current compounds CMC, CMC/PAA,
Vinasse and V/CMC-PAA

this study, XRD data was used to observe the crystallinity and amorphously value of all the prepared samples. (Fig. 4) indicates the comparison between XRD ofpure CMC polymer, CMC/PAA hydrogel, Vinasse and
V/CMC-PAA. The CMC spectrum illustrates two relatively sharp peaks of the semi-crystalline nature of carboxymethyl cellulose structure at 2θ = 25.3° and 53.3°

Figure 5 represents the indistinct morphological dissimilarities of pure CMC, CMC/PAA hydrogel, Vinasse
and V/CMC-PAA samples. The surface morphologyof CMC was found to be really tubes [35], as shown in(Fig. 5A). Meanwhile, (Fig. 5B) describes the surface
structure of the CMC/PAA hydrogel as dark homogenous, and compact clouds with the presence of cavities
and the appearance of CMC tubes. This feature gives
a good indication for the synthesis of hydrogel CMC/
PAA. These cavities have a vital role in the capture andstorage of water. (Fig. 5C) indicates the morphologicalstructure of Vinasse was homogenous and represented
as compact white spheres in addition to small whiteslides and lumps. Furthermore, (Fig. 5D) illustrates the
micro-topography image of the capsulation and coatingof Vinasse through hydrogel. These bright white slides
and spots point out the successful coating of Vinasse
by hydrogel. Active absorption sites toward the soil
increase in tandem with the specific surface area of thevinasse.

Dardeer et al. BMC Chemistry(2024) 18:144

Page 7 of 13

Fig. 5 SEM images of A pure CMC, B CMC/PAA, C Vinasse (V), and D V/CMC-PAA

Application in agriculture field
Water absorption mechanism of CMC/PAA

The main mechanism for the absorption of water byhydrogel (CMC/PAA) depend on the presence of hydrophilic groups in the hydrogel chain, such as (–COOH,–OH). The water penetrates the hydrogel system byosmosis pressure differences [13]. On the other hand,the carboxy groups that are attached to the main chainof the hydrogel (CMC/PAA) lose hydrogen atoms andleave behind negative ions that run along the main chainof the hydrogel. The repulsion that occurs between
these negative charges makes the hydrogel chain attract
the water molecules and bond with them by hydrogenbonding. Subsequently, it stores a large number of watermolecules. This type of hydrogel can absorb more than
400 times its weight of water (Fig. 6). When it begins to
dry out, the hydrogel gradually releases about 95% of its
stored water and repeats this process with time [13]. It
is important to note that the surface morphology plays
a vital role in the adsorption mechanism of water molecules on the surface of hydrogel, as we mentioned anddiscussed in the SEM section (Fig. 5B). The surface sample contains caves, pores, and some cracks that make theabsorption process more effective in the hydrogel sample.
Vinasses characterization

The Egyptian Vinasse presented a pH of 4.76, which was
higher than that reported by Parsaee et.al [37]. The low
pH is due to the presence of acids in the medium, such as
acetic, butyric, lactic, and formic acids. The COD value(36.27%) showed that a lot of organic compounds, including polysaccharides, lignin, hemicellulose, proteins, melanoidin, and wax, were still present after distillation in
all of the processes [38]. The concentration of potassium
is 9.2%, phosphorus is 0.26% and the concentration of
nitrogen is 2.88%. Similar data were reported by Hernández et al. [39] in Vinasse extracted from sugarcane.
Capsulation mechanism of vinasse by CMC/PAA

Vinasses are the liquid waste that results from the endof the distillation process of ethanol [40]. Vinasses contain high concentrations of organic matter, low pH,

Dardeer et al. BMC Chemistry(2024) 18:144

Page 8 of 13

Fig. 6 Water absorption mechanism of CMC/PAA

electric conductivity, and mineral salts [37]. Also, it
contains a high concentration of NPK; therefore, it isconsidered an effective fertilizer in agriculture fields,
but it has some problems, such as its high solubility inwater, which makes the nutrient compounds lose theirvalue during the leaching process. To overcome thisproblem, Vinasse was coated with hydrogel, as shownin (Fig. 7). The coating process depends on many forces,

Fig. 7 Capsulation of vinasse by CMC/PAA

such as the hydrogen bonding between the active
groups of hydrogel and the active groups present in
Vinasse, Hydrophilic-hydrophilic interaction, in addition to the coordination bonds between the elements
and the carboxylic groups in the prepared hydrogel,according to this process, the final product acts as aslow-release organic fertilizer.

Dardeer et al. BMC Chemistry(2024) 18:144

Page 9 of 13

Table 4 Comparison between the release rate of ­K+ in leachedsoln. in case of using Vinasse only (A) and using of (V/CMC-PAA)(B)(A) Potassium content (Vinasse)(B) Potassium content (V/
CMC-PAA)Time (h)K+ (ppm)

Time (day)K+ (ppm)

2

650

1

30

4

440

5

28

6

340

10

35

10

150

15

37

15

78

20

30

20

58

25

22

25

40

30

19

30

21

35

20

35

20

40

17

40

21

45

15

50

14

45

18

50

19

55

18

60

14

Potassium release rate

The results show that the prepared slow release organic
fertilizer hydrogel (V/CMC-PAA) is more effective thanVinasse itself. Since, (V/CMC-PAA) can control therelease rate of potassium, Table 4A, B investigates thefollowing process for the concentration of potassium inleached water in the cases of using Vinasse alone (4A)and Vinasse with hydrogel (4B). The results illustrate thatthe concentration of potassium was very high at about

650 ppm after two hours and reached 14 ppm through
60 h, as shown in Table 4A and (Fig. 8). But in the caseof using Vinasse with hydrogel CMC/PAA the concentration of potassium in leached water has the same value
after 50 days, as shown in Table 4B and (Fig. 8).
Evaluation of EC

Table 5A, B, (Fig. 9) show the EC values for the leachedwater in the case of using Vinasse only and after applying
V/CMC-PAA. The results indicate that the values of EC
in the case of using Vinasse itself decreased from 47.4 to
20 mmohs/cm through the first six hours. It’s clearly evident that these values show the high EC of Vinasse, whichcauses the damage of plants by salinity chalk. In contrast,
the EC value after applying V/CMC-PAA through thefirst six hours was 1.77 to 0.35 mmohs/cm. These results
showed that by using the hydrogel with Vinasse as SRFH,
the plant was protected from the salinity chalk. Therefore, V/CMC-PAA is considered a potential slow releaseorganic fertilizer and meets the requirements of alkalinesoil. Moreover, it will be most suitable for Egyptian agricultural fertilizers. All these results were carried out by
using the device as shown in (Fig. 10A, B).
The application of (V/CMC‑PAA) on cane sugar crops

The production of the cane sugar crop was evaluated byexamining cane stalk weight, cane stalk height, and thequality of the juice produced through measuring purity
and reducing sugar after 360 days. This study was applied
to one Hectare from cane sugar crops. This area wasdivided into two parts. The first part was treated by the
prepared V/CMC-PAA, and the second part was treated

K+ (ppm)

700
600
500
400
300
200
100
0

K+ (ppm)

K+ (ppm)

K+ (ppm)

020

40Time (hr)

60

40
35
30
25
20
15
10
5
0
0

20

40

Time (day)K+ (ppm)

VinasseFig. 8 The release rate of potassium ­K+ in leached solution

K+ (ppm)

V/CMC-PAA

60

Dardeer et al. BMC Chemistry(2024) 18:144

Page 10 of 13

Table 5 Comparison between the EC in leached water in case of
Vinasse itself (A) and V/CMC-PAA (B)(A) EC (Vinasse)(B) EC (V/CMC-PAA)

Time (h)EC (mmohs/cm)

Time (h)EC (mmohs/cm)

2

47.4

2

1.77

4

31.3

4

0.34

6

20

6

0.35

10

0.65

10

0.37

15

0.34

15

0.38

20

0.2

20

0.3

25

0.19

25

0.21

30

0.15

30

0.21

35

0.12

35

0.21

40

0.13

40

0.18

45

0.11

45

0.25

50

0.13

50

0.11

55

0.11

60

0.09

The suggested biodegradability of combined SROFH‑V/
CMC‑PAA

by Vinasse itself (control). The results show that the characterization of the cane sugar crop treated with V/CMCPAA as a slow-release organic fertilizer has distinctive
properties compared to the crop treated with Vinasse
only. The average cane stalk weight in the case of Vinasse
itself is 1.28 kg, while in the case of using V/CMC-PAA
is 1.74 kg. Also, the average cane stalk height when using
Vinasse alone is 2.3 m, while when using coated Vinasse
was 2.9 m. The cane juice purity in using Vinasse itself is84.2 and became 85.6 by using V/CMC-PAA. Moreover,the concentration of reducing sugar in juice in the caseof using V/CMC-PAA was 5.16 and in the control was
3.61. The P­ 2O5 percentage was 160 ppm in the control,
while it was 180 ppm in the case of coated Vinasse. The
productivity per feddan increased from 32 tons in the

Biodegradability is known as a chemical change incompounds due to chemical breakdown processes by
microorganisms or enzymes [41]. The biodegradability
procedure is based on the category of polymers, such as
natural, synthetic, and combination polymers. Combination polymers have been widely investigated for thedevelopment of hydrogels with improved properties.
There are several methods to measure the biodegradability of hydrogels in soil. Such as the examination of thequantity of evaporated carbon dioxide from the soil andthe hydrogel, the determination of the biochemical oxygen demand (BOD) of the improved soil compared to
the natural soil, calculating weight loss through the soil
burial method, investigating the growth of microbial biomass, determining the changes in the physical propertiesof the hydrogel with time [42], and using the hydrogelwith radioactive 14C and tracking the 14C in the C­ O2 or­CH4 released from the metabolism of the polymer. Soil
burial testing is the most widely used to study the biodegradability of hydrogels [43]. The degradation rate of ahydrogel was found to be 5.9% under aerobic conditions
over about 500 days, as reported by Huettermann et al.
[43]. The rates of decomposition of crosslinked polyacrylate hydrogels were reported to be in the range of
1–9% per year. The biodegradation of polyacrylate-basedhydrogels occurred by microorganisms that utilized thecarbon backbone as a carbon source [44]. Using CMC asa hydrogel incorporating polyacrylic acid increases thebiodegradation rate. Secondly, increasing the nutrient
amount increased the biodegradation of the hydrogel, as

Vinasse

2

50
40
30
20
10
0

EC (mmohs/cm)

EC (mmohs/cm)

EC (mmohs/cm)

case of Vinasse itself to 38 tons after using V/CMC-PAA.
This means productivity will increase by about 15% perfeddan. In addition, the number of irrigations decreased
from 5 to 4 by using V/CMC-PAA Table 6.

0

10

20

30

40

50

60

70

Time (hr)EC (mmohs / cm)
Fig. 9 The EC in leached water in case of Vinasse itself and V/CMC-PAA

EC (mmohs/cm)

V/CMC-PAA

0

40

1.5
1
0.5
0
20

Time (day)EC (mmohs/cm)

60

Dardeer et al. BMC Chemistry(2024) 18:144

Page 11 of 13

Fig. 10 Experimental device setup for Vinasse release study (A) Original device, (B) Graphic device

Table 6 The effect of CMC-PAA hydrogel on sugar cane andcane juice quality after season of cultivation
Analysis

Control (Vinasse)

Treated
V/CMCPAA

Average cane stalk weight—kg

1.28

1.74

Average cane stalk height—m

2.3

2.9

Theoretical sugar yield—%

11.47

12.11

Cane juice purity

84.2

85.6

Reducing sugar % Bx in juice

3.61

5.16

P2O5 “ppm” in juice

160

180

Number of irrigations (times)

5

4

Productivity per feddan (tons)

32

38

the microbes responsible for the biodegradation process.
The bio-based hydrogel CMC/PAA was degradable byusing the soil burial method and measuring weight loss
[45]. The biodegradation rate was found to be 43.6% after
100 days, and this rate was dependent on the type of soil.

• 2 kg of hydrogel (CMC/PAA) is required to encapsulate 60 kg of Vinasse.
• For 1.0 ton of coated vinasse, the quantity of hydrogel(V/CMC-PAA) is 33.3 kg (2 × 1000/60).
• To manufacture 50 tons of coated Vinasse, an estimated 1670 kg (33.3 × 50) of hydrogel (CMC/PAA) is
needed.
• One kilogram of hydrogel costs 0.5 USD.
• Vinasse is priced at $20 per ton.
• About 120 kg of coated Vinasse are added per hectare.
• 4 kg of hydrogel were utilized to encapsulate 120 kg
of Vinasse.
• Therefore, the increase in fertilization expenses per
hectare will be approximately 2 USD (4 * 0.5).
• Sugar cane harvest costs 45 USD per ton.
• The profit realized from an increase in sugar
cane crop productivity is 270 USD per hectare(38−32) × 45.
• The net gain is calculated as the increase in productivity—the increase in fertilization costs (270−2 = 268
USD per hectare).

Economic study

The following economic analysis can be deduced fromour previous laboratory-scale experiments: this study
was conducted on May 15, 2024.
• The daily production rate of solid Vinasse at the Abo
Korkas sugar and distillation factory is 50 tons.

Conclusion
In this study, a promising combined hydrogel containing carboxymethyl cellulose and polyacrylic CMC/PAA
was prepared and characterized by different methods
to be used as a slow-release organic fertilizer hydrogel
for Vinasse. The FTIR and XRD analyses proved theDardeer et al. BMC Chemistry(2024) 18:144

formation of hydrogel via the changes that occur in the
FTIR spectrum and the XRD pattern. Also, the SEM
analysis showed a difference in the morphology structure of Vinasse before and after coating with hydrogel. The Vinasse powder was coated with the preparedhydrogel to control the releasing process of potassiumfrom Vinasse, this technique is known as slow releasepotassium from Vinasse. Also improving the physicalproperties of Vinasse such as salinity and porosity. The
application field on cane sugar crops proves that theEC value after applying V/CMC-PAA through the firstsix hours was 1.77 to 0.35 mmohs/cm. This indicatesthe plant will be saved from the salinity chalk, whichis raised by the highly increased EC of Vinasse itself.
Therefore, V/CMC/PAA is considered a potential slow
release organic fertilizer and meets the requirements ofalkaline soil. Also, using V/CMC-PAA can control andkeep the potassium as fertilizer for 50 days. Furthermore, the cane stalk weight, cane stalk height, the quality of the juice produced, and the cane juice purity forcane sugar crops were increased. The productivity per
feddan was enhanced from 32 to 38 tons after using V/
CMC-PAA by about 15% per feddan, and the number ofirrigations decreased from 5 to 4 times.
Acknowledgements
The authors express their gratitude to Prof. M. F. Aly for his help, advice, andencouragement. Spirit Prof. Dr. Abd-El-Fatah Harb. Also, the authors are very
grateful to Dr. Ahmed S. Ibrahim and Dr. Ahmed M. El-Naggar for their help.
Author contributions
Hemat M. Dardeer and Mohamed Y. Mahgoub designed the research, wrote
the manuscript, prepared it, and edited it for publication. Hemat M. Dardeer
and Mohamed Y. Mahgoub were also responsible for the correspondence ofthe manuscript. Hemat M. Dardeer, Mohamed Y. Mahgoub and Ahmed N. Gad
conducted the experimental part. All authors approved the final version.
Funding
Open access funding provided by the Science, Technology & Innovation Funding Authority (STDF) in cooperation with The Egyptian Knowledge Bank (EKB).
Availability of data and materials
The datasets used and/or analysed during the current study are available fromthe corresponding author on reasonable request.

Declarations
Ethics approval and consent to participate
Not applicable.
Consent for publication
Not applicable.
Competing interests
The authors declare that they have no competing financial or non-financial
interests.
Received: 26 November 2023 Accepted: 9 July 2024

Page 12 of 13

References
1. Van den Broek LAM, Knoop RJI, Kappen FHJ, Boeriu CG. Chitosan films
and blends for packaging material. Carbohydr Polym. 2015;116:237–42.
https://​doi.​org/​10.​1016/j.​carbp​ol.​2014.​07.​039.
2. Kalia S, Avérous L. Biodegradable and biobased polymers for environmental and biomedical applications. Hoboken: John Wiley & Sons Inc;
2016.
3. Elschner T, Obst F, Heinze T. Furfuryl- and maleimido polysaccharides:
synthetic strategies toward functional biomaterials. Macromol Biosci.
2018;18:1800258. https://​doi.​org/​10.​1002/​mabi.​20180​0258.
4. Ni B, Liu M, Lü S. Multifunctional Slow-Release Urea Fertilizer from
Ethylcellulose and Superabsorbent Coated Formulations. Chem Eng J.
2009;155:892–8. https://​doi.​org/​10.​1016/j.​cej.​2009.​08.​025.
5. Wang W, Wang A. Synthesis, swelling behaviors, and slow-releasecharacteristics of a guar gum-g-poly (sodium acrylate)/sodium humate
superabsorbent. Appl Polym Sci. 2009;112:2102–11. https://​doi.​org/​10.​
1002/​app.​29620.
6. Azeem B, KuShaari K, Man Z. Effect of coating thickness on releasecharacteristics of controlled release urea produced in fluidized bed
using waterborne starch biopolymer as coating material. Proced Eng.
2016;148:282–9. https://​doi.​org/​10.​1016/j.​proeng.​2016.​06.​615.
7. De Feo G, Ferrara C, Iannone V, Parente P. Improving the efficacy ofmunicipal solid waste collection with a communicative approach basedon easily understandable indicators. Sci Total Environ. 2019;651:2380–90.
https://​doi.​org/​10.​1016/j.​scito​tenv.​2018.​10.​161.
8. Kose I, Cekmecelioglu D, Meral A, Avni H. Evaluation of heterotrophic andmixotrophic cultivation of novel Micractinium sp. ME05 on vinasse andits scale up for biodiesel production. Bioresour Technol. 2017;251:128–34.
https://​doi.​org/​10.​1016/j.​biort​ech.​2017.​12.​023.
9. da Silva Paredes D, da Lessa ACR, de Sant’Anna SAC, Boddey RM, Urquiaga
S, Alves BJR. Nitrous oxide emission and ammonia volatilization inducedby vinasse and N fertilizer application in a sugarcane crop at Rio deJaneiro, Brazil. Nutr Cycl Agroecosyst. 2014;98(1):41–55. https://​doi.​org/​
10.​1007/​s10705-​013-​9594-5.
10. Kusumaningtyas RD, Oktafiani O, Hartanto D, Handayani PA. Effects ofsolid vinasse-based organic mineral fertilizer on some growth indices oftomato plant. Jurnal Bahan Alam Terbarukan. 2017;6(2):190–7. https://​doi.​
org/​10.​15294/​jbat.​v6i2.​12507.
11. Christofoletti CA, Escher JP, Correia JE, Marinho JFU, Fontanetti CS.
Sugarcane vinasse: environmental implications of its use. J Waste Manag.
2013;3(12):2752–61. https://​doi.​org/​10.​1016/j.​wasman.​2013.​09.​005.
12. Fuess LT, Rodrigues IJ, Garcia ML. Fertirrigation with sugarcane vinasse:
foreseeing potential impacts on soil and water resources through vinassecharacterization. J Environ Sci Health Part A. 2017;52(11):1063–72. https://​doi.​org/​10.​1080/​10934​529.​2017.​13388​92.
13. Saruchi, Kaith BS, Jindal R, Kapur GS, Kumar V. Synthesis, characterizationand evaluation of Gum tragacanth and acrylic acid based hydrogel forsustained calcium chloride release—enhancement of water-holding
capacity of soil. J Chin Adv Mater Soc. 2014;2(1):40–52. https://​doi.​org/​10.​
1080/​22243​682.​2014.​893412.
14. Laftah WA, Hashim S. The influence of plant natural fibers on swelling
behavior of polymer hydrogels. J Compos Mater. 2014;48:555–69. https://​doi.​org/​10.​1177/​00219​98313​476323.
15. Kohls SJ, Baker DD, Kremer DA, Dawson JO. Water-retentive polymers
increase nodulation of actinorhizal plants inoculated with Frankia. Plant
Soil. 1999;214:105–15. https://​doi.​org/​10.​1023/A:​10046​34804​354.
16. Huttermann A, Orikiriza LJB, Agaba H. Application of superabsorbent
polymers for improving the ecological chemistry of degraded or polluted
lands. Clean. 2009;37:517–26. https://​doi.​org/​10.​1002/​clen.​20090​0048.
17. Yangyuoru M, Boateng E, Adiku SGK, Acquah D, Adjadeh TA, Mawunya F.
Effects of natural and synthetic soil conditioners on soil moisture retention and maize yield. West Afr J Appl Ecol. 2007;9:6–18. https://​doi.​org/​10.​4314/​wajae.​v9i1.​45676.
18. Ros AR. Slow release fertilizer hydrogels: a review. Polym Chem.
2019;10:6073–90. https://​doi.​org/​10.​1039/​C9PY0​1036J.
19. Zhan F, Liu M, Guo M, Wu L. Preparation of superabsorbent polymer
with slow-release phosphate fertilizer. Appl Polym Sci. 2004;92:3417–21.
https://​doi.​org/​10.​1002/​app.​20361.
20. Younes HA, Taha M, Mahmoud R, Mahmoud HM, Abdelhameed RM. Highadsorption of sodium diclofenac on postsynthetic modified zirconiumbased metal-organic frameworks: experimental and theoretical studies. J

Dardeer et al. BMC Chemistry

21.

22.
23.

24.

25.

26.
27.
28.

29.

30.

31.

32.
33.

34.

35.

36.

37.
38.

(2024) 18:144

Colloid Interface Sci. 2022;607:334–46. https://​doi.​org/​10.​1016/j.​jcis.​2021.​
08.​158.
Emam HE, El-Shahat M, Abdelhameed RM. Observable removal of pharmaceutical residues by highly porous photoactive cellulose acetate@
MIL-MOF film. J Hazard Mater. 2021;414:125509. https://​doi.​org/​10.​1016/j.​jhazm​at.​2021.​125509.
Emam HE, Shaheen TI. Investigation into the role of surface modificationof cellulose nanocrystals with succinic anhydride in dye removal. J Polym
Environ. 2019;27:2419–27. https://​doi.​org/​10.​1007/​s10924-​019-​01533-9.
Abdelhameed RM, Alzahrani E, Shaltout AA, Emam HE. Temperaturecontrolled-release of essential oil via reusable mesoporous composite of
microcrystalline cellulose and zeolitic imidazole frameworks. J Ind Eng
Chem. 2021;294:134–44. https://​doi.​org/​10.​1016/j.​jiec.​2020.​10.​025.
Dhuiège B, Pecastaings G, Sèbe G. Sustainable approach for the directfunctionalization of cellulose nanocrystals dispersed in water by transesterification of vinyl acetate. ACS Sustain Chem Eng. 2019;7:187–96.
https://​doi.​org/​10.​1021/​acssu​schem​eng.​8b028​33.
Boulven M, Quintard G, Cottaz A, Joly C, Charlot A, Fleury E. Homogeneous acylation of cellulose diacetate: towards bioplastics with tuneable
thermal and water transport properties. Carbohydr Polym. 2019;206:674–
84. https://​doi.​org/​10.​1016/j.​carbp​ol.​2018.​11.​030.
Liang R, Yuan H, Xi G, Zhou Q. Synthesis of wheat straw-g-poly (acrylicacid) superabsorbent composites and release of urea from it. Carbohydr
Polym. 2009;77:181–7. https://​doi.​org/​10.​1016/j.​carbp​ol.​2008.​12.​018.
Aniket K, Rajeew K, Singh VP, Pandey DS. Hydrogels: a boon for increasing agricultural productivity in water-stressed environment. Curr Sci.
2016;111(11):1773–9.
Ghorpadea VS, Yadavb AV, Dias RJ. Citric acid crosslinked β-cyclodextrin/carboxymethylcellulose hydrogel films for controlled delivery of poorly
soluble drugs. Carbohydr Polym. 2017;164:339–48. https://​doi.​org/​10.​1016/j.​carbp​ol.​2017.​02.​005.
De Lima GF, De Souza AG, Rosa DS. Nanocellulose as reinforcement incarboxymethylcellulose superabsorbent nanocomposite hydrogels.
Macromol Symp. 2020;394:2000126. https://​doi.​org/​10.​1002/​masy.​20200​
0126.
Uliniuc A, Hamaide T, Popa M, Bacait S. Modified starch-based hydrogels
cross-linked with citric acid and their use as drug delivery systems forlevofloxacin. Soft Mater. 2013;11:483–93. https://​doi.​org/​10.​1080/​15394​
45X.​2012.​710698.
Ahmed SI, Ahmed NG, Dardeer HM, Abdel-Aal MG. Novel green biodegradable clarifying agents in sugar refining process using functionalized
chitosan nanocomposites. Sustain Mater Technol. 2023;35: e00525.
https://​doi.​org/​10.​1016/j.​susmat.​2022.​e00525.
Li X, Tabil LG, Panigrahi S. Chemical treatments of natural fiber for
use in natural fiber-reinforced composites: a review. J Polym Environ.
2007;15:25–33. https://​doi.​org/​10.​1007/​s10924-​006-​0042-3.
Arslanoglu E, Eren M, Arslanoglu H, Ciftci H. Fabrication characterization, and adsorption applications of low-cost hybride activated carbons
from peanut shell-vinasse mixtures by one-step pyrolysis. Biomass
Convers Biorefinery. 2023;13:2321–35. https://​doi.​org/​10.​1007/​
s13399-​021-​01400-5.
Santiago MAL, Campos JR, Villalobos RR, Hernández EG, Cardona AAV,
Ramos SMC. Thermal treatment to obtain 5-Hydroxymethyl Furfural(5-HMF), Furfural and phenolic compounds from vinasse waste fromagave. Molecules. 2023;28:1063. https://​doi.​org/​10.​3390/​molec​ules2​
80310​63.
Dardeer HM, Mahgoub MY, Abouzeid RE, Owda ME, Ahmed FM. Novelpseudopolyrotaxane composite based on biopolymers: Synthesis,characterization and application in water treatment. Environ Nanotechnol Monit Manag. 2022;17:100639. https://​doi.​org/​10.​1016/j.​enmm.​2021.​
100639.
Dardeer HM, Abbas SA, El-Sayyad GS, Moustafa FA. Effect of titanium
dioxide nanoparticles and β-cyclodextrin polymer on physicochemical,
antimicrobial, and antibiofilm properties of a novel chitosan-camphor
polymer. Int J Biol Macromol. 2022;219:1062–79. https://​doi.​org/​10.​1016/j.​
ijbio​mac.​2022.​07.​249.
Parsaee M, Kiani MKD, Karimi K. Review of biogas production from sugarcane vinasse. Biomass Bioenergy. 2019;122:117–25. https://​doi.​org/​10.​1016/j.​biomb​ioe.​2019.​01.​034.
Singh A, Rodríguez-Jasso RM, Saxena R, Cerda RB, Singhania RR, Ruiz HA.
Subcritical water pretreatment for agave bagasse fractionation fromPage 13 of 13

39.

40.
41.
42.
43.

44.

45.

tequila production and enzymatic susceptibility. Bioresour Technol.
2021;338:125536. https://​doi.​org/​10.​1016/j.​biort​ech.​2021.​125536.
Hernández D, Rebolledo-Leiva R, Fernández-Puratich H, Quinteros-Lama
H, Cataldo F, Muñoz E, Tenreiro C. Recovering apple agro-industrial waste
for bioethanol and vinasse joint production: screening the potential of
Chile. Fermentation. 2021;7:203. https://​doi.​org/​10.​3390/​ferme​ntati​on704​0203.
Rodrigues Reis CE, Hu B. Vinasse from sugarcane ethanol production:better treatment or better utilization? Front Energy Res. 2017;5:7. https://​doi.​org/​10.​3389/​fenrg.​2017.​00007.
Andrady AL. Engineering & technology Dirsian. In: Andrady AL, editor.
Physical properties of polymers handbook, vol. 56. Research Triangle Park:
RTI International; 2007. p. 951–61.
Hamid SH. Handbook of polymer degradation. New York: CRC Press; 2000.
https://​doi.​org/​10.​1201/​97814​82270​181.
Huettermann A, Orikiriza LJ, Agaba H. Effects of hydrogel amendment
to different soils on plant available water and survival of trees underdrought conditions. Clean Soil Air Water. 2009;37:517–26. https://​doi.​org/​
10.​1002/​clen.​20090​0245.
Xiong B, Loss RD, Shields D, Pawlik T, Hochreiter R, Zydney AL, Kumar
M. Polyacrylamide degradation and its implications in environmental systems. NPJ Clean Water. 2018;1:17. https://​doi.​org/​10.​1038/​
s41545-​018-​0016-8.
Adjuik TA, Nokes SE, Montross MD. Biodegradability of bio-based and synthetic hydrogels as sustainable soil amendments: a review. Appl Polym
Sci. 2023;140: e53655. https://​doi.​org/​10.​1002/​app.​53655.

Publisher’s NoteSpringer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.