Real cotton fabric industry wastewater (CFIWW) was treated using the novel electrochemical coagulation (ECC) technology by stainless steel (SS) and copper (Cu) electrodes for applied cell current 1.5 and 4.4 A for a maximum electrolysis time of 30 min. Pre-characterization of CFIWW before ECC showed higher values of chemical oxygen demand (COD), colour, chloride, alkalinity and other quality parameters. Removal of COD and total dissolved solids (TDS) was 97 and 94% for 30.2 V and 4.4 A while using a Cu electrode. The ECC obtained sludge produced 3.13 g/L for Cu and 11.2 g/L for SS for 4.4 A, and 0.43 and 3.98 g/L for 1.5 A. The analysis of ECC sludge was conducted using a scanning electron microscope (SEM), energy dispersive X-ray spectroscopy (EDS) and Fourier-transform infrared spectroscopy (FT-IR). The SEM images of ECC sludge showed unstructured, irregular morphology with uneven edges and rough surfaces. The elemental composition of sludge was studied using EDS showing the presence of copper, oxygen, sodium, sulphur and iron. The FT-IR spectra of ECC sludge for Cu- and SS-mediated ECC-generated sludge showed the presence of alcohol and carboxyl groups at several wave numbers. The specific energy consumption (SEC) for Cu was lower than SS.

  • This research work shows a focus on treating real cotton fabric industry wastewater using the novel electrochemical treatment (ECT) technology for the removal of COD, chloride and TDS. Copper and stainless steel plate were used as electrodes to achieve maximum removal of pollutants. The sludge is also analysed through SEM, EDS, FT-IR and the sludge volume index is estimated.

Graphical Abstract

Graphical Abstract
Graphical Abstract
View largeDownload slide
Graphical Abstract
Graphical Abstract
View largeDownload slide
copper and stainless steel electrodes, cotton fabric industry wastewater, electrochemical coagulation, sludge volume index

Fabric manufacturing is one of the largest and oldest industries in the world. India is the third largest exporter of textiles worldwide, preceded by China and the European Union. The Indian fabric industry is the world's largest base raw material producer (Yadav et al. 2013). In India, there are 3,400 textile mills; the fabric industry contributes to 14% of the annual industrial production with 4% of the GDP, 18% of employment and 27% of foreign exchange (Prajapati et al. 2016). The fabric manufacturing process steps include sizing, desizing, scouring, bleaching, dyeing and finishing. The dyeing and finishing processes during fabric manufacture generates large quantities of wastewater loaded with chemicals contributing to non-biodegradable matter (Sarayu & Sandhya 2012). Cotton fabric industry wastewater (CFIWW) is loaded with organic and inorganic materials, heavy metals and many colourants. The different types of dyes used in textile wet processing are acid dyes, basic dyes, direct dyes, mordant dyes, sulphur dyes, azoic dyes, vat dyes, reactive dyes, disperse dyes, synthetic dyes, pigment dyes, macromolecular dyes, metalized dyes, premetallized dyes, naphthol dyes, developed dyes, aniline dyes and anthraquinone dyes (Benkhaya et al. 2020). More than 10,000 dyes are currently available commercially, of which azo dyes are the largest group commonly used in textile industries because of their chemical stability.

Currently, chemical and biological processes for the treatment of CFIWW are applied in real scale treatment: chemical coagulation and flocculation (Verma 2017), adsorption (Rashid et al. 2021), oxidation (Hassaan et al. 2017) and biological methods such as activated sludge process (Haddad et al. 2018), aerobic and anaerobic treatment (Shoukat et al. 2019), and biological degradation using photocatalysis (Ceretta et al. 2020). These conventional treatment methods are neither effective nor efficient in the complete removal of contaminants/pollutants; they require a large number of unit operations/processes, high hydraulic retention time (HRT), high energy foot print, high capital cost (Singh et al. 2018), operational and maintenance cost, and most importantly, they are non-robust and less reliable than conventional treatment systems (Mahesh et al. 2022).

In the past two decades, ECT is found to be effective for the treatment of a wide variety of wastewater, namely coffee processing wastewater (Sahana et al. 2018), bakery industry wastewater (de Santana et al. 2018), tannery wastewater (Basha et al. 2009), sugarcane process industry wastewater (Sahu et al. 2017), food processing industry wastewater (Barrera-Díaz et al. 2006), distillery wastewater (Thakur et al. 2009), dairy wastewater (Venkata Mohan et al. 2010), petroleum industry wastewater (Treviño-Reséndez et al. 2021), hospital wastewater (Singh et al. 2018; Mahesh et al. 2022), pulp and paper mill wastewater (Mahesh et al. 2006a, 2006b). Most research work pertaining to fabric industry wastewater focuses on single waste dye streams or the use of synthetic wastewater. The challenge is to deal with real wastewater by removing pollutants and applying the best treatment methods. Therefore, in this work, we propose the use of real wastewaters (CFIWW) for in-depth characterization followed by ECT using two different electrode materials, Cu and SS, for the removal of COD, salts, alkalinity and TDS from raw CFIWW. The electrochemical coagulation (ECC) sludge characteristics obtained after treatment are also reported.

Raw wastewater collection and characterization

The CFIWW was collected from Nanjangud, an industrial hub 15 km south of Mysuru city. The initial characterization of raw CFIWW before ECC was carried out as per standard procedures for the analysis described in Standard Methods (APHA 2017).

Experimental setup

A 1 L working volume batch electrochemical reactor (ECR) vessel was made of plexiglass. Two-dimensional copper (Cu) and stainless steel (SS) plate electrodes of known specific electrode area to volume ratio (SA/V) were used in the ECC experiments. Four plates each of electrode dimensions 10 cm × 5 cm, giving an SA/V of 20 m2/m3, were used. The electrodes were placed in parallel in the reactor; the extreme anode and cathode electrodes were connected to the DC power supply unit. The electrodes were weighed before and after the ECC process and the difference in weight loss was noted to understand the extent of metal dissolution and the quantity of sludge generated. Batch ECC was carried out for two different applied cell currents of 1.5 and 4.4 A for a pre-optimized electrolysis time (ET) of 30 min. The ECR was continuously stirred with the aid of a magnetic bead at a speed of 350–390 rpm using an inductive magnetic stirring unit. During ECC, the wastewater samples at 10-min time intervals were retrieved and analysed for the mentioned select quality parameters. After 30 min ET, the experiments were terminated and the treated effluent was allowed to settle and then filtered before parameter analysis. The settled sludge was collected in a Petri dish, dried in the oven at 80 ± 2 °C and then weighed. The oven dried sludge was further characterized using SEM, energy-dispersive X-ray spectroscopy (EDS) and FT-IR and for determining the sludge volume index (SVI). Figure 1 shows the ECC experimental approach.
Figure 1
Experimental approach methodology for ECC of real CFIWW.
View largeDownload slide

Experimental approach methodology for ECC of real CFIWW.

Figure 1
Experimental approach methodology for ECC of real CFIWW.
View largeDownload slide

Experimental approach methodology for ECC of real CFIWW.

Close modal

Characterization of CFIWW

Pre-characterization of raw CFIWW was required before ECC, as it provided input for choosing the appropriate electrode materials. The grab sample technique was used to collect CFIWW at the end of the pipe (EOP). The characteristics of raw CFIWW are shown in Table 1. All quality parameters were analysed in duplicate and the range of values is reported. Table 2 also provides EOP discharge standards in general, not specific to fabric manufacturing wastewaters.

Table 1

Characterization of raw CFIWW

Sl. No.ParametersUnitsEOP CPCB discharge standards for disposal into
Parameter value of CFIWW
Public sewerLandWater
1 pH – 5.5–9.0 5.5–9.0 5.5–9.0 7.63 ± 0.2 
2 Electrical conductivity μS/cm a a a 5.85 ± 0.3 
3 Turbidity NTU 50 a a 380–420 
4 Total alkalinity as CaCO3 mg/L a a a 1,500–1,540 
5 Chloride mg/L a a a 1,107–1,137 
6 Total suspended solids (TSS) mg/L a a a 1,050–1,960 
7 Total dissolved solids (TDS) mg/L 2,100 2,100 a 4,740–5,820 
8 Total hardness (TH) as CaCO₃ mg/L 300 a a 850–870 
9 Sulphate mg/L a a a 160–199 
10 COD mg/L a a 250 6,300–6,500 
11 BOD5 mg/L 350 100 30 1,500–1,600 
Sl. No.ParametersUnitsEOP CPCB discharge standards for disposal into
Parameter value of CFIWW
Public sewerLandWater
1 pH – 5.5–9.0 5.5–9.0 5.5–9.0 7.63 ± 0.2 
2 Electrical conductivity μS/cm a a a 5.85 ± 0.3 
3 Turbidity NTU 50 a a 380–420 
4 Total alkalinity as CaCO3 mg/L a a a 1,500–1,540 
5 Chloride mg/L a a a 1,107–1,137 
6 Total suspended solids (TSS) mg/L a a a 1,050–1,960 
7 Total dissolved solids (TDS) mg/L 2,100 2,100 a 4,740–5,820 
8 Total hardness (TH) as CaCO₃ mg/L 300 a a 850–870 
9 Sulphate mg/L a a a 160–199 
10 COD mg/L a a 250 6,300–6,500 
11 BOD5 mg/L 350 100 30 1,500–1,600 

Source: Government of India through Central Pollution Control Board (CPCB), New Delhi, India for wastewater discharge into different receptors.

aNot available.

View Large
Table 2

SVI values of ECC sludge of CFIWW

No.Raw wastewaterElectrode materialCell voltage/currentETSVIReferences
1 CFIWW Cu 16 V/1.5 A 30 min 90 This work 
34.1 V/4.4 A 140 
SS 16 V/1.5 A 220 
34.1 V/4.4 A 380 
2 Hospital wastewater Al 8 V 60 min 240 Mahesh et al. (2022)  
Cu 8 V 210 
Fe 8 V 146 
3 Healthcare facility wastewater Al 12 V 60 min 79 Singh et al. (2018)  
SS 18 V 160 
4 Pulp and paper mill wastewater Fe 5 A 90 min 312 Mahesh et al. (2006b) 
No.Raw wastewaterElectrode materialCell voltage/currentETSVIReferences
1 CFIWW Cu 16 V/1.5 A 30 min 90 This work 
34.1 V/4.4 A 140 
SS 16 V/1.5 A 220 
34.1 V/4.4 A 380 
2 Hospital wastewater Al 8 V 60 min 240 Mahesh et al. (2022)  
Cu 8 V 210 
Fe 8 V 146 
3 Healthcare facility wastewater Al 12 V 60 min 79 Singh et al. (2018)  
SS 18 V 160 
4 Pulp and paper mill wastewater Fe 5 A 90 min 312 Mahesh et al. (2006b) 
View Large

The initial pH (pHo) of raw CFIWW was 7.63 in the near neutral range, slightly alkaline. pH is an important parameter because metal ions form several metal hydroxides and the coagulated species remove the contaminants from the wastewater. The second most important parameter is total alkalinity (TA) which assists in the formation of electro-flocs, thereby aiding the removal of pollutants from the waste stream (Mahesh et al. 2022). The TA present in raw CFIWW was 1,500–1,540 mg/L and chloride 1,107–1,137 mg/L, COD and BOD values were relatively high, i.e. 6,300–6,500 mg/L and 1,500–1,600 mg/L.

Batch ECC of CFIWW

The results of the ECC process treating raw CFIWW are reported and discussed in the following sub-sections.

pH variations for Cu and SS electrodes

Figure 2 shows the variation in pH during the ECC process while using Cu and SS electrodes for 30 min ET. In the case of Cu, the pHo was 7.63 which gradually increased to 8.94 at 30 min ET for 1.5 A cell current. Similarly, for Cu for the current of 4.4 A, the pH increased to 9.31 at 30 min ET. In the case of SS for both 1.5 and 4.4 A, the pH of ECC supernatant increased to 8.94. The increase in pH of the bulk solution is ascribed to the release of large quantities of OH− ions by hydrolysis (Singh et al. 2018). The pH value increased by 1.7 units for Cu and 1.9 units for SS from the initial value of 7.63.
Figure 2
pH variations during ECC for Cu and SS electrodes.
View largeDownload slide

pH variations during ECC for Cu and SS electrodes.

Figure 2
pH variations during ECC for Cu and SS electrodes.
View largeDownload slide

pH variations during ECC for Cu and SS electrodes.

Close modal

Total dissolved solid removal

Total dissolved solid (TDS) is known as a quality parameter depicting mostly inorganic substances in dissolved form. Figure 3 shows TDS removal during ECC using Cu and SS electrodes. For both Cu and SS, TDS reductions were recorded during ECT. In the case of Cu, TDS removal was 91.6% for 4.4 A and 94.9% for 1.5 A. The Cu electrode showed higher TDS removal ascribed to the release of small sized Cu ions into the solution, that were able to pick dissolved constituents from the wastewater to form electro-floc (Mahesh et al. 2022); and removed as scum to the top the ECR.
Figure 3
TDS removal during ECC operation for Cu and SS electrodes.
View largeDownload slide

TDS removal during ECC operation for Cu and SS electrodes.

Figure 3
TDS removal during ECC operation for Cu and SS electrodes.
View largeDownload slide

TDS removal during ECC operation for Cu and SS electrodes.

Close modal

A higher cell current of 4.4 A for SS was able to remove TDS marginally from the solution, whereas 1.5 A current could not remove TDS from the bulk solution. Salt utilization in forming floc and simultaneous release of weakly charged M+ ions at low cell current (1.5 A) in the case of SS, resulted in no change of TDS in the ECC treated supernatant. In the absence of sufficient charge, there is a tendency for TDS values to increase during ECC with ET (Singh et al. 2018).

Chloride removal

The decrease in the chloride values in the post-ECC supernatant was similar for both the Cu and SS electrode materials. Figure 4 shows the utilization of chloride for scum/sludge formation during the ECC process. It is believed that the chloride present in CFIWW was converted into hypochlorous acid and hypochlorite ions (Sahana et al. 2018) depending on the prevailing pH of the wastewater.
Figure 4
Chloride reduction during ECC for Cu and SS electrodes.
View largeDownload slide

Chloride reduction during ECC for Cu and SS electrodes.

Figure 4
Chloride reduction during ECC for Cu and SS electrodes.
View largeDownload slide

Chloride reduction during ECC for Cu and SS electrodes.

Close modal

Chloride reduction during ECC is the result of the oxidation of Fe2+ ions into Fe3+ ions (Sahana et al. 2018). A cell voltage of 4.4 A for SS electrodes showed 94% chloride removal compared to 88% TDS removal for the same cell current using Cu.

TA utilization

Figure 5 shows alkalinity utilization aiding in floc formation during the ECC process for using Cu and SS electrodes. In an ECC process, some alkalinity is used in the formation of floc as insoluble metal hydroxide precipitates and its species (Mahesh et al. 2006b). It may be seen from the plots that alkalinity utilization is higher for SS than Cu. Alkalinity removal for 4.4 A was 89 and 98% for Cu and SS electrodes respectively at 30 min ET. A simultaneous decrease in the pH of the bulk solution was observed. Maximum alkalinity was utilized at ∼20 min ET at which time the corresponding pH was ∼8.2 favouring floc formation as per the Pourbaix. It is surmised that total hardness (TH) of raw CFIWW of 860 mg/L also favours ECC floc formation. The sludge volume can slightly increase because of alkalinity and TH utilization in the ECC process (Mahesh et al. 2006a).
Figure 5
Total alkalinity reduction during ECC for Cu and SS electrodes.
View largeDownload slide

Total alkalinity reduction during ECC for Cu and SS electrodes.

Figure 5
Total alkalinity reduction during ECC for Cu and SS electrodes.
View largeDownload slide

Total alkalinity reduction during ECC for Cu and SS electrodes.

Close modal

COD removal

Total COD is a contribution of both biodegradable and non-biodegradable materials in the wastewater. The non-biodegradable components in CFIWW are mostly dyes and chemicals that contribute to high COD values. Figure 6 shows the variation in COD during ECC while using Cu and SS electrodes. The initial COD value of CFIWW before ECC was 4,800 mg/L. Maximum COD reduction was 95% for 1.5 A and 96% for 4.4 A for Cu electrodes. The salt content in wastewater (Cl−) enhances the electrode dissolution (ED) resulting in COD removal by forming insoluble precipitates. The presence of salts also increases the sludge volume after ECC, giving high SVI values. The electro generated metal ions form monomeric ions, ferric hydro complexes with hydroxide ions and polymeric species depending on the solution pH during ECC. Several iron and aluminium species such as ⁠, ⁠, ⁠, ⁠, ⁠, ⁠, etc., contribute to precipitate out the oxygen demanding substances from the waste stream during the ECC process; the COD degradation mechanism is described in detail elsewhere.
Figure 6
COD reduction during ECC for Cu and SS electrodes.
View largeDownload slide

COD reduction during ECC for Cu and SS electrodes.

Figure 6
COD reduction during ECC for Cu and SS electrodes.
View largeDownload slide

COD reduction during ECC for Cu and SS electrodes.

Close modal

The chloride ions in CFIWW were able to dissolve the passive oxide film that had formed on the anode surface causing a reduction in metal dissolution and electron transfer, thereby increasing the COD removal efficiency. Interestingly, for 1.5 A cell current using SS, the COD removal was zero; this condition can occur when the relative applied cell current is low, wherein the metal dissolution is high in a salty environment; and a poor charge on M+ ions results in COD addition to the waste stream, making it much more turbid.

ED and sludge quantification

The metal electrodes used in the ECC process are a prime consumable material that initiates treatment. The operation and maintenance cost of the ECC system entirely depends on the cell voltage, the corresponding current and the extent of ED for a specified HRT. Excess salts in the wastewater erode the electrode metal surface in the stipulated HRT and also increase COD (Gotsi et al. 2005) making the wastewater more turbid; as also high SVI values. Figure 7(a) and 7(b) show ED and sludge quantity for Cu and SS electrodes in the ECC process. The chloride content in the wastewater at a higher cell current induces higher ED adding to the solids content in the bulk solution. Compared to copper, the sludge generation by SS electrodes was high. SS electrode showed high ED and more sludge production. For Cu electrodes at a cell current of 1.5 A, 0.413 g/L sludge was produced and 3.13 g/L for 4.4 A applied current respectively. Similarly, for SS electrode, the sludge produced was 3.9 g/L for 1.5 A and 11.2 g/L for 4.4 A applied current. The alkaline pHf of bulk solution after ECC causes higher electrode consumption by an order of magnitude (Mahesh et al. 2006a).
Figure 7
(a) Electrode dissolution and sludge weight for Cu electrodes. (b) Electrode dissolution and sludge weight for SS electrodes.
View largeDownload slide

(a) Electrode dissolution and sludge weight for Cu electrodes. (b) Electrode dissolution and sludge weight for SS electrodes.

Figure 7
(a) Electrode dissolution and sludge weight for Cu electrodes. (b) Electrode dissolution and sludge weight for SS electrodes.
View largeDownload slide

(a) Electrode dissolution and sludge weight for Cu electrodes. (b) Electrode dissolution and sludge weight for SS electrodes.

Close modal

Analysis of ECC sludge

Sludge production is an inevitable part of a biological/chemical/ECT process. The ECC process is very effective in controlling sludge volume as desired (Shivaprasad & Mahesh 2022).

Sludge volume index

SVI is an important operating parameter to characterize sludge and estimate the cost effectiveness of the ECC process. It is used to quantify the settling characteristics of the ECC generated sludge. SVI is defined as the volume of sludge occupied by 1 g of sludge after 30 min settling in a column. SVI values were estimated using the relation shown in the following equation.
formula
(1)
where H30 is the height of sludge in cm after 30 min of settling in the column, Ho is the initial height of slurry in cm and Xo is the initial solids concentration of the ECC slurry in mg/L. Table 2 shows SVI values obtained in this work compared to other SVI treating different wastewaters using ECC. The SVI values obtained were low for copper at 1.5 and 4.4 A compared to SS. SVI values are relevant for exercising control over the degree of treatment required (Shivaprasad & Mahesh 2022).

Energy-dispersive X-ray spectroscopy

EDS is a method used for the chemical characterization of elemental materials present in a substance. The ECC sludge collected from both Cu and SS electrodes was dried and subject to EDS analysis. Figure 8(a) and 8(b) show the EDS spectra of the ECC sludge for Cu and SS electrodes. The constituents in sludge showed the presence of Cu 42.95%, C and O 30.49 and 26.56%, respectively. For SS generated ECC sludge, Fe 7.27%, C 23.62%, O 42.02%, Na 19.86%, and S 7.23%.
Figure 8
(a) EDS spectra of ECC sludge for Cu. (b) EDS spectra of ECC sludge for SS.
View largeDownload slide

(a) EDS spectra of ECC sludge for Cu. (b) EDS spectra of ECC sludge for SS.

Figure 8
(a) EDS spectra of ECC sludge for Cu. (b) EDS spectra of ECC sludge for SS.
View largeDownload slide

(a) EDS spectra of ECC sludge for Cu. (b) EDS spectra of ECC sludge for SS.

Close modal

Fourier-transform infrared spectroscopy

Fourier-transform infrared spectroscopy (FT-IR) measures the intensity over a wavelength range from 400 to 4,000 cm−1. In Figure 9, the curves are obtained in the finger print zone and the bands are seen in the pattern of stretching and bending.
Figure 9
FT-IR spectra of ECC sludge for Cu and SS.
View largeDownload slide

FT-IR spectra of ECC sludge for Cu and SS.

Figure 9
FT-IR spectra of ECC sludge for Cu and SS.
View largeDownload slide

FT-IR spectra of ECC sludge for Cu and SS.

Close modal

In the functional range of 4,000–1,500 cm−1 stretching and vibrations are observed. For SS, at 1,500 and 1,800 cm−1 N–H stretch indicate the presence of amines. At 2,977 cm−1, there is a C–H showing the presence of carboxylic acid. At 3,752 cm−1, the alkyne O–H stretch is found to show alcohol. For Cu at 1,519 cm−1, an aromatic ring stretch is observed. At 3,679, 3,806, 3,972 cm−1, O–H bonding is present. An alkene C–H stretch at 2,973 cm−1 is observed (Aragaw & Aragaw 2020).

Scanning electron microscopy

The scanning electron microscopy (SEM) was used to understand the morphology of ECC obtained sludge samples. The morphology of Cu sludge showed non-uniformity in distribution (Figure 10(a)) and definite Cu structures. Figure 10(b) shows SS sludge as unstructured, irregular, sharp uneven edges with rough surfaces. The ECC sludge appeared sturdy, similar to granular activated carbon. This statement is based on certain facts: (i) gravity settling and filtration, (ii) density and specific gravity of sludge, (iii) porous structure of ECC sludge (Singh et al. 2018) and (iv) less bound water.
Figure 10
(a,b) SEM images of ECC sludge for Cu and SS.
View largeDownload slide

(a,b) SEM images of ECC sludge for Cu and SS.

Figure 10
(a,b) SEM images of ECC sludge for Cu and SS.
View largeDownload slide

(a,b) SEM images of ECC sludge for Cu and SS.

Close modal

Real CFIWW was treated in an ECR using Cu and SS electrodes in a bipolar arrangement for cell voltages 12.7 and 30.2 V, respectively, and their corresponding current at a low HRT of 30 min. Wastewater quality parameters monitored were pH, chloride, alkalinity, COD and TDS. The ED, sludge volume and SVI were determined. This information is useful in estimating the life cycle of an electrode, designing an ECR, evaluating operation and maintenance costs, sludge handling and arriving at logical end disposal/reuse of ECC sludge. SEM, EDS and FT-IR for the ECC sludge were reviewed for morphology, elemental composition and functional groups. Pre-ECC and post-ECC characterization for COD, TDS, chlorides and alkalinity were evaluated for ECC treated effluent. The experimental results showed that ECC is a promising novel technology giving the least HRT for treating cotton fabric industry wastewaters. The specific energy consumption (SEC) worked out to 20–42 kW/kg of COD removed for Cu, and 31–56 kW/kg of COD removed for SS, respectively.

The authors thank JSS Science and Technology University, Mysuru Karnataka State, India for providing research infrastructure in the specialized electrochemical treatment laboratory in the Department of Environmental Engineering to carry out this research work.

All relevant data are included in the paper or its Supplementary Information.

The authors declare there is no conflict.

APHA (American Public Health Association)
2017
In:
Standard Methods for the Examination of Water and Wastewater
, 23rd edn (
Baird Rodger
B.
,
Eaton Andrew
D.
 &
Rice Eugene
W.
 eds.).
American Public Health Association (APHA)
,
Washington, DC
, p.
1504
.
978-0-87553-287-5
.
Google Scholar
 
Barrera-Díaz
C.
,
Roa-Morales
G.
,
Ávila-Córdoba
L.
,
Pavón-Silva
T.
 &
Bilyeu
B.
2006
Electrochemical treatment applied to food-processing industrial wastewater
.
Industrial and Engineering Chemistry Research
45
(
1
),
34
–
38
.
https://doi.org/10.1021/ie050594k.
Google Scholar
Crossref
Search ADS
 
Basha
C. A.
,
Soloman
P. A.
,
Velan
M.
,
Balasubramanian
N.
 &
Kareem
L. R.
2009
Participation of electrochemical steps in treating tannery wastewater
.
Industrial and Engineering Chemistry Research
48
(
22
),
9786
–
9796
.
https://doi.org/10.1021/ie900464s.
Google Scholar
Crossref
Search ADS
 
Benkhaya
S.
,
M’ rabet
S.
 &
el Harfi
A.
2020
A review on classifications, recent synthesis and applications of textile dyes
. In:
Inorganic Chemistry Communications
, Vol.
115
.
Elsevier B.V
.
https://doi.org/10.1016/j.inoche.2020.107891.
Google Scholar
Crossref
Search ADS
 
Ceretta
M. B.
,
Vieira
Y.
,
Wolski
E. A.
,
Foletto
E. L.
 &
Silvestri
S.
2020
Biological degradation coupled to photocatalysis by ZnO/polypyrrole composite for the treatment of real textile wastewater
.
Journal of Water Process Engineering
35
.
https://doi.org/10.1016/j.jwpe.2020.101230
.
Google Scholar
 
de Santana
M. M.
,
Zanoelo
E. F.
,
Benincá
C.
 &
Freire
F. B.
2018
Electrochemical treatment of wastewater from a bakery industry: experimental and modeling study
.
Process Safety and Environmental Protection
116
,
685
–
692
.
https://doi.org/10.1016/j.psep.2018.04.001.
Google Scholar
Crossref
Search ADS
 
Gotsi
M.
,
Kalogerakis
N.
,
Psillakis
E.
,
Samaras
P.
 &
Mantzavinos
D.
2005
Electrochemical oxidation of olive oil mill wastewaters
.
Water Research
39
(
17
),
4177
–
4187
.
Google Scholar
Crossref
Search ADS
PubMed
 
Haddad
M.
,
Abid
S.
,
Hamdi
M.
 &
Bouallagui
H.
2018
Reduction of adsorbed dyes content in the discharged sludge coming from an industrial textile wastewater treatment plant using aerobic activated sludge process
.
Journal of Environmental Management
223
,
936
–
946
.
https://doi.org/10.1016/j.jenvman.2018.07.009.
Google Scholar
Crossref
Search ADS
PubMed
 
Hassaan
M.
,
Nemr
A. e.
 &
Hassaan
M. A.
2017
Advanced oxidation processes for textile wastewater treatment
.
International Journal of Photochemistry and Photobiology
2
(
3
),
85
–
93
.
https://doi.org/10.11648/j.ijpp.20170203.13.
Google Scholar
 
Mahesh
S.
,
Prasad
B.
,
Mall
I. D.
 &
Mishra
I. M.
2006a
Electrochemical degradation of pulp and paper mill wastewater. part 1. COD and color removal
.
Industrial and Engineering Chemistry Research
45
(
8
),
2830
–
2839
.
https://doi.org/10.1021/ie0514096.
Google Scholar
Crossref
Search ADS
 
Mahesh
S.
,
Prasad
B.
,
Mall
I. D.
 &
Mishra
I. M.
2006b
Electrochemical degradation of pulp and paper mill wastewater. Part 2. Characterization and analysis of sludge
.
Industrial and Engineering Chemistry Research
45
(
16
),
5766
–
5774
.
https://doi.org/10.1021/ie0603969
.
Google Scholar
Crossref
Search ADS
 
Mahesh
S.
,
Shivaprasad
K. S.
 &
Sanjana
M.
2022
Ayurvedic hospital wastewater degradation using electrochemical treatment
.
Water Science and Technology
85
(
6
),
1855
–
1877
.
https://doi.org/10.2166/wst.2022.079.
Google Scholar
Crossref
Search ADS
PubMed
 
Prajapati
A. K.
,
Sharma
N.
,
Jena
R. K.
,
Shrimal
P.
,
Bagtharia
P.
,
Kaushal
R. K.
 &
Pal
D.
2016
Electrochemical treatment of cotton textile-based dyeing effluent
.
Separation Science and Technology (Philadelphia)
51
(
13
),
2276
–
2283
.
https://doi.org/10.1080/01496395.2016.1204318.
Google Scholar
Crossref
Search ADS
 
Rashid
R.
,
Shafiq
I.
,
Akhter
P.
,
Iqbal
M. J.
 &
Hussain
M.
2021
A state-of-the-art review on wastewater treatment techniques: the effectiveness of adsorption method
.
Environmental Science and Pollution Research
28
(
8
),
9050
–
9066
.
https://doi.org/10.1007/s11356-021-12395-x
.
Google Scholar
Crossref
Search ADS
PubMed
 
Sahu
O.
,
Rao
D. G.
,
Gopal
R.
,
Tiwari
A.
 &
Pal
D.
2017
Treatment of wastewater from sugarcane process industry by electrochemical and chemical process: aluminum (metal and salt)
.
Journal of Water Process Engineering
17
,
50
–
62
.
https://doi.org/10.1016/j.jwpe.2017.03.005.
Google Scholar
Crossref
Search ADS
 
Sarayu
K.
 &
Sandhya
S.
2012
Current technologies for biological treatment of textile wastewater-A review
.
In Applied Biochemistry and Biotechnology
167
(
3
),
645
–
661
.
https://doi.org/10.1007/s12010-012-9716-6.
Google Scholar
Crossref
Search ADS
 
Shivaprasad
K. S.
 &
Mahesh
S.
2022
Electrochemical treatment of two health-care wastewaters – a comparative study
.
Separation Science and Technology.
57
(
14
),
2323
–
2339
.
Google Scholar
 
Shoukat
R.
,
Khan
S. J.
 &
Jamal
Y.
2019
Hybrid anaerobic-aerobic biological treatment for real textile wastewater
.
Journal of Water Process Engineering
29
.
https://doi.org/10.1016/j.jwpe.2019.100804.
Google Scholar
 
Singh
S.
,
Mahesh
S.
,
Sahana
M.
 &
Puneeth
K. M.
2018
Treatment of healthcare facility wastewaters by two dimensional (2D) electrochemical coagulation (ECC), settling and filterability aspects
.
Journal of Water Process Engineering
26
,
200
–
220
.
https://doi.org/10.1016/j.jwpe.2018.10.009
.
Google Scholar
Crossref
Search ADS
 
Thakur
C.
,
Srivastava
V. C.
 &
Mall
I. D.
2009
Electrochemical treatment of a distillery wastewater: parametric and residue disposal study
.
Chemical Engineering Journal
148
(
2–3
),
496
–
505
.
https://doi.org/10.1016/j.cej.2008.09.043
.
Google Scholar
 
Treviño-Reséndez
J. d. J.
,
Medel
A.
 &
Meas
Y.
2021
Electrochemical technologies for treating petroleum industry wastewater
. In:
Current Opinion in Electrochemistry
, Vol.
27
.
Elsevier B.V
.
https://doi.org/10.1016/j.coelec.2021.100690
.
Google Scholar
Crossref
Search ADS
 
Venkata Mohan
S.
,
Mohanakrishna
G.
,
Velvizhi
G.
,
Babu
V. L.
 &
Sarma
P. N.
2010
Bio-catalyzed electrochemical treatment of real field dairy wastewater with simultaneous power generation
.
Biochemical Engineering Journal
51
(
1–2
),
32
–
39
.
https://doi.org/10.1016/j.bej.2010.04.012
.
Google Scholar
 
Verma
A. K.
2017
Treatment of textile wastewaters by electrocoagulation employing Fe-Al composite electrode
.
Journal of Water Process Engineering
20
,
168
–
172
.
https://doi.org/10.1016/j.jwpe.2017.11.001
.
Google Scholar
Crossref
Search ADS
 
Yadav
A.
,
Mukherji
S.
 &
Garg
A.
2013
Removal of chemical oxygen demand and color from simulated textile wastewater using a combination of chemical/physicochemical processes
.
Industrial and Engineering Chemistry Research
52
(
30
),
10063
–
10071
.
https://doi.org/10.1021/ie400855b.
Google Scholar
Crossref
Search ADS
 
© 2023 The Authors
This is an Open Access article distributed under the terms of the Creative Commons Attribution Licence (CC BY 4.0), which permits copying, adaptation and redistribution, provided the original work is properly cited (http://creativecommons.org/licenses/by/4.0/).