Textile Dyeing Wastewater Research Articles

Treatment of textile dye wastewater by peroxymonosulfate activation using facilely prepared Fe3O4@TiO2 heterogeneous photocatalyst

AbstractIn this study, Fe3O4@TiO2 was synthesized by a facile precipitation–impregnation method and applied as a magnetic photocatalyst for degrading synthetic and actual textile dyeing wastewater in the presence of peroxymonosulfate (PMS). In Rhodamine B (RhB) degradation, the removal efficiency reached 99.86% (for RhB) and 93.67% (for color) under optimal operating conditions of 80 mg L–1 RhB, 0.5 g L–1 PMS, 0.5 g L–1 Fe3O4@TiO2, at pH 6, and after 30 min of UVA irradiation. The influence levels of anions on the RhB removal and decolorization were in the order of Cl− < SO42− < CO32− < PO43−. In addition, the Fe3O4@TiO2 composite exhibited good applicability for treating other dyes (e.g., 99.6% of tartrazine and 60.3% of methylene blue after 30 min) in water and actual textile dyeing wastewater with high color (70.3% after 5 min) and COD removal (71.4% after 120 min). The radical scavenging tests indicated the role of reactive oxygen species in the order of O2•− ∼ 1O2 > h+ > SO4•− > HO• for RhB degradation but O2•− > h+ > 1O2 > SO4•− > HO• for decolorization. These results suggest the potential application of PMS activation using Fe3O4@TiO2 in the photocatalytic treatment of textile and dyeing wastewater with the dominant role of O2•−.

Removal of Disperse Yellow-42 Dye by Catalytic Ozonation Using Iron and Manganese-Loaded Zeolites

In this research, the efficiency of the catalytic activity of iron and manganese-loaded (bimetallic) sodium zeolite was investigated for the ozonation-based removal of disperse yellow 42 dye. The impregnation method was used to deposit Fe and Mn on the surface of sodium zeolite. The morphological analysis of sodium zeolite before and after Fe and Mn deposition was conducted by SEM, EDX, and FTIR. It was found that several variables, including the ozone dose, contact time, pH, catalyst dose, and hydroxyl radical scavenger action, greatly influenced the efficiency of dye removal. The chemical oxygen demand (COD) removal by catalytic ozonation using Fe and Mn-loaded sodium zeolite from real dye textile wastewater was also investigated. After 30 min of treatment with catalytic ozonation at pH 6, the maximum 73% removal of disperse yellow 42 dye was achieved with a catalyst dose of 0.5 g and an ozone dose supply of 1.8 mg/min. In catalytic ozonation with the hydroxyl radical scavenger effect (HRSE), the decline in removal efficiency from 73% to 61% demonstrated that removal efficiency was highly dependent on hydroxyl radical production. The COD removal efficiency in the real textile wastewater was 59% with the ozonation process, which increased to 79% after catalytic ozonation.

Photocatalytic Degradation of Textile Dyeing Wastewater Using Titanium Dioxide on a Fixed Substrate: Optimization of Process Parameters and Continuous Reactor Tests

Herein, a preparation of a mixed-phase titanium dioxide (TiO2) thin layer on glass beads was developed using the modified spray method. This approach was determined to be affordable and easy to operate. Optimum conditions were investigated for the photodegradation of wastewater generated from textile dyeing by TiO2-coated glass beads as a catalyst using the central composite design (CCD). An increase in the direct dye photodegradation rate was observed at lower direct dye concentrations when TiO2 dosages were increased, and the initial pH value was decreased. The optimal conditions involving TiO2 dosage, pH, UV intensity, and dye concentrations were 3 g/L, 5.0, 3000 µW/cm2, and 50 mg/L, respectively, when administered at ambient temperatures. For the batch experiments, the direct dye removal efficiency at 93.7% was achieved within 24 h. The average direct dye removal efficiency was 67.8% and could be up to 80.2% when using a fixed-bed photocatalysis reactor during 30 d of continuous operation. The reused catalyst’s degradation efficiency was not significantly changed, indicating its capability for repeated reuse and the excellent stability of immobilized TiO2 onto the glass beads. This study additionally found that high temperatures could increase the efficiency of color removal.

Comparison of aerobic and anoxic-oxic sequential batch reactors for treating textile wastewater

ABSTRACT The discharge of untreated textile dyeing wastewater containing azo dyes has significant ecological consequences. The incomplete biodegradation of these dyes can produce harmful and carcinogenic aromatic amines (AAs), which pose a threat to the environment. This study evaluates the treatment of real textile dyeing wastewater containing azo dyes by two different systems: an anoxic sequential batch reactor (A/O-SBR) and an aerobic sequential batch reactor (A-SBR). The effects of hydraulic retention time (HRT) on both systems were investigated in terms of chemical oxygen demand (COD), total nitrogen (TN), color, and AAs removal. Ranging between 85% and 92%, the COD removal efficiency was almost similar in the A/O-SBR and A-SBR systems, suggesting that the aerobic phase is primarily responsible for COD removal. However, A/O-SBR showed higher removal of color (90%) than A-SBR (75%) due to the presence of an anoxic phase. HRT has a significant impact on color removal in both systems. However, there was no significant effect on COD removal when HRT exceeded 12 h. According to LC-MS/MS analysis, increasing the HRT from 12 h to 24 h increased the AAs concentration in the anoxic phase, from 253 ng/L to 261 ng/L and slightly decreased the AAs concentration in the aerobic phase from 107 ng/L to 102 ng/L. This resulted in an overall improvement in both dye and AAs removal. The presence of aerobic phase in A/O-SBR and A-SBR demonstrates strong AAs removal capacity. GC-MS/MS analysis indicated that as the HRT of A/O-SBR and A-SBR increased, the number of by-products increased.

Research on ultrafast catalytic degradation of heterocyclic compounds by the novel high entropy catalyst

Traditional refractory wastewater treatment methods have problems of low efficiency, high cost and many by-products, so it is of great significance to develop new high-efficiency refractory wastewater treatment technology. Heterogeneous catalysts were used in the catalytic ultrafast oxidation (CUFO) process to treat textile dyeing wastewater with refractory heterocyclic compounds. Composite catalysts with varying entropies were synthesized by the ultrasonic dispersion-annealing method. The high entropy catalysts exhibited superior catalytic activity and stability compared to other catalysts. Furthermore, the impact of reaction temperature (T, 350–390 °C), residence time (t, 3–17 min), oxidation coefficient (OC, 2.1–2.9), and entropy of catalyst on the COD removal were assessed. An increase in entropy of catalyst resulted in a significant enhancement of COD removal rate. At T = 390 °C and OC = 2.90, the high entropy oxides catalyst achieved the COD removal rate of 93.95 % after the 7 min reaction. Additionally, a catalytic reaction mechanism involving the CeMnCuOx solid solution heterostructure with domino catalytic ability was proposed. Overall, the results suggest that catalytic ultrafast oxidation technology is a promising option for efficiently treating refractory organic pollutants.

Heterogeneous Fenton treatment of actual textile and dyeing wastewater by α-Cu-FeOOH nanomaterial

This work reports the successful synthesis and application of α-Cu-FeOOH in heterogeneous Fenton treatment of actual textile dyeing wastewater. The material characteristics were analyzed by SEM, EDX, BET, FTIR, and XRD methods. In heterogeneous Fenton tests, the highest TOC and color removal efficiencies were found to be 46.88 and 37.98%, respectively, in the suitable conditions of Cu/Fe molar ratio = 5%, [H2O2] = 0.1 M, [α-Cu-FeOOH] = 0.6 g/L, pH = 7, and after 60 min. The values of color and TOC after treatment well met the discharge standard for textile dyeing wastewater (QCVN 13:2015/BTNMT, Column B). The presence of copper in the material enhanced the activation of H2O2 in heterogeneous Fenton reactions under neutral environments. Therefore, α-Cu-FeOOH material has great potential for practical application in textile wastewater treatment with an initial color of 185.6 mg/L and TOC concentration of 72.54 mg/L.

Dysbiosis of gut microbiota by actual long-term exposure to textile wastewater treatment plant effluents in adult zebrafish (Danio rerio) using aquatic microcosm systems

In the future, textile industry wastewater may create greater possibilities of releasing emerging contaminants into aquatic environments. Research on textile dyeing wastewater has focused on its adverse effects on biota. However, the effects of textile wastewater on gut microbiome and host health have not yet been elucidated, especially for the toxic assessment of combined pollutants under receiving water environment conditions. During this study, adult zebrafish were exposed to realistic textile wastewater treatment plant (TWTP) effluents in aquatic microcosm systems (AMS) for six months, a histopathological examination was performed, after which 16S rRNA and metagenomic sequencing of the intestinal microbiota was conducted and fish growth performance was also examined. As a result of exposure to TWTP effluents, adult zebrafish growth was significantly inhibited, the condition factor was exacerbated, and mortality was significantly increased. Also, significant alterations were observed in zebrafish guts after chronic exposure, which are the opportunistic pathogens Flavobacterium, Aeromonas, and Escherichia. The chronic effects of increased probiotic Cetobacterium, Bacteroides, and Planctomyces deserve further attention. Metagenomic sequencing also showed that genes of core metabolism pathways were affected by TWTP effluent exposure. The study has, for the first time, demonstrated gut microbiota's susceptibility and host health of adult zebrafish to TWTP effluents using aquatic microcosm systems, which are assumed to be clean, thus warranting additional research to reveal their mode of toxicity.

Antifouling and Chemical-Resistant Nanofiltration Membrane Modulated by a Functionalized MWCNT Interlayer for Efficient Dye/Salt Separation at High Salinity.

Dye/salt separation in textile wastewater is of great importance. Membrane filtration technology is an environmentally friendly and effective approach to solve this issue. In this study, a thin-film composite membrane with a tannic acid (TA)-modified carboxylic multiwalled carbon nanotube (MWCNT) interlayer (M-TA) was prepared by interfacial polymerization with amino-functionalized graphene quantum dots (NGQDs) acting as aqueous monomers. The addition of the M-TA interlayer favored the formation of a thinner, more hydrophilic, and smoother selective skin layer for the composite membrane. The pure water permeability of the M-TA-NGQDs membrane was ∼9.32 L m-2 h-1 bar-1, which was higher than that of the NGQDs membrane without the interlayer. Meanwhile, the M-TA-NGQDs membrane presented better methyl orange (MO) rejection (97.79%) than the NGQDs membrane (87.51%). The optimal M-TA-NGQDs membrane exhibited excellent dye rejection (Congo red (CR): 99.61%; brilliant green (BG): 96.04%) and low salt rejection (NaCl < 15%). Noticeably, the M-TA-NGQDs membrane displayed effective selective separation performance (CR and BG > 99%) for dye/NaCl mixed solutions even at a high NaCl concentration of 50,000 mg/L. Furthermore, the M-TA-NGQDs membrane presented high water permeability recovery ratio values (91.02-98.20%). Importantly, the M-TA-NGQDs membrane showed excellent chemical stability (acid/alkali resistance). Generally, the fabricated M-TA-NGQDs membrane exhibited a great prospect for applications in dye wastewater treatment and water recycling, especially for the effective selective separation of dye/salt mixtures for high-salinity textile dyeing wastewater.

Occurrences and fates of per- and polyfluoralkyl substances in textile dyeing wastewater along full-scale treatment processes

Industrial wastewater is a substantial source of per- and polyfluoroalkyl substances (PFASs) in the environment. However, very limited information is available on the occurrences and fates of PFASs along industrial wastewater treatment processes, particularly for the textile dyeing industry where PFASs occur extensively. Herein, the occurrences and fates of 27 legacy and emerging PFASs were investigated along the processes of three full-scale textile dyeing wastewater treatment plants (WWTPs) based on UHPLC−MS/MS in combination with self-developed solid extraction protocol featuring selective enrichment for ultrasensitive analysis. The total PFASs ranged at 630-4268 ng L−1 in influents, 436-755 ng L−1 in effluents, and 91.5-1182 μg kg−1 in the resultant sludge. PFAS species distribution varied among WWTPs, with one WWTP dominated by legacy perfluorocarboxylic acids while the other two dominated by emerging PFASs. Perfluorooctane sulfonate (PFOS) was trivial in the effluents from all the three WWTPs, indicating its diminished use in textile industry. Various emerging PFASs were detected at different abundances, demonstrating their use as alternatives to legacy PFASs. Most conventional processes of the WWTPs were inefficient in removing PFASs, especially for the legacy PFASs. The microbial processes could remove the emerging PFASs to different extents, whereas commonly elevated the concentrations of legacy PFASs. Over 90% of most PFASs could be removed by reverse osmosis (RO) and was enriched into the RO concentrate accordingly. The total oxidizable precursors (TOP) assay revealed that the total concentration of PFASs was increased by 2.3-4.1 times after oxidation, accompanied by formation of terminal perfluoroalkyl acids (PFAAs) and degradation of emerging alternatives to various extents. This study is believed to shed new light on the monitoring and management of PFASs in industries.

Enhanced photocatalytic performance of W-doped TiO2 nanoparticles for treatment of Procion Red MX-5B azo dye in textile wastewater

Sol-gel synthesis of W-doped TiO2 nanoparticles (W-TiO2) as a photocatalyst for Procion Red MX-5B (MX-5B) azo dye treatment in textile wastewater was the main focus of this research. Scanning electron microscopy (SEM), X-ray diffractometer (XRD), X-ray photoelectron spectroscopy (XPS), and energy dispersive spectroscopy (EDS) structural studies of nanostructured photocatalysts showed that W was successfully incorporated into the TiO2 lattice. According to EIS investigations, W-TiO2 has a greater rate of charge transfer and excellent charge separation capabilities compared to a sample of pure TiO2. It shows the W-TiO2 nanostructured photocatalyst sample's exceptional photocatalytic performance. The band gap energies of TiO2 and W-TiO2 were determined through optical studies to be 3.22 eV and 2.93 eV, respectively, showing an improvement in the photocatalytic activity of TiO2 in the visible light domain. Studies of the photocatalytic performance indicated that the full treatment of MX-5B molecules was achieved after 105, 100, 95, 80, 70, 85, and 90 min of exposure to visible light for pure TiO2, W0.5-TiO2, W1-TiO2, W3-TiO2, W5-TiO2, W8-TiO2, and W10-TiO2, respectively. These studies revealed the great and quick photocatalytic treatment of MX-5B in the presence of doped TiO2. The results of a study that used 400 mL of a 40 mg/L MX-5B solution prepared with deionized water as a control sample and a sample of actual textile wastewater as a real sample showed that MX-5B from actual textile wastewater was effectively photocatalytically degraded in the presence of W5-TiO2 photocatalyst.

Assessment of Azo Dye in Textile Wastewater and Examination of the Fire Safety Measures in Garment Industries in Tirupur District, India

Assessment of Azo Dye in Textile Wastewater and Examination of the Fire Safety Measures in Garment Industries in Tirupur District, India

DISCUSSION ON TREATMENT EFFICIENCY OF REACTIVE YELLOW 145 COLOR AND REACTIVE RED COLOR 194 BY GUM EXTRACTED FROM MORINGA OLEIFERA SEEDS

The treatment of wastewater , in general , and wastewater containing dyes , in particular, has long been studied, to find not only effective treatment methods but also treatment materials that do not generate additional pollutants. These should be eco- friendly and inexpensive material s which also , make use of discarded or rarely used resources. The current trend is towards a circular economy where waste from one industry is an input for another and helps to reduce environmental pollution. In this study, a biological coagulant (gum) extracted from moringa seeds is produced as a coagulant to treat Reactive Y e llow 145 (RY145) and Reactive Red 194 (RR194). The material's properties are determined by scanning electron microscopy (SEM) and FTIR analysis methods. SEM images show that the surface structure of the gum biomaterial extracted from moringa seeds has the appearance of relatively fine pores and relatively homogenously distributed gum particles on the surface. FTIR spectra indicate that the prepared material contains surface functional groups such as –OH, –HC=O , and C-O of the xyloglucan ring. The factors affecting the coagulation process of RY145 and R R 194 colors include pH, gum concentration, initial color, stirring speed , and stirring time. From the empirical results, it is suggested that the bio-flocculating agent (gum) prepared from moringa seeds, an eco-friendly material , can decolorize and reduce COD, and thus, possess great potential for application in the treatment of textile dyeing wastewater, with RY145 and COD removal efficiency of 87.77% and 76.92% respectively, and RR194 and COD removal efficiency of 89.31% and 80% respectively.

A comprehensive study on flocculation of anionic dyes using the bioflocculant produced by Bacillus thuringiensis: Kinetics, affecting factors, and perspectives.

Bioflocculants have received more and more attention as alternatives to chemical flocculants because of their innocuousness, environmental friendliness, and high effectiveness. This study aims to investigate various factors that influence the performance of the novel bioflocculant produced by Bacillus thuringiensis (BF-TWB10) and analyze its adsorption kinetics to optimize its flocculation performance for real applications. The best-fit kinetic model was pseudo-second order with R2 = 0.999. The effects of pretreatment temperature, pH, and the presence of cations on flocculation were assessed. Further investigations of flocculation, including zeta potential analysis and particle size analysis, were also conducted. Thermal pretreatment of BF-TWB10 or the presence of divalent cations could stimulate the decolorization efficiency of the bioflocculant. BF-TWB10 manifested outstanding dye removal performances with over 90% for all tested anionic dyes at pH2 and 3. Its decolorization efficiency on anionic dyes decreased with the increase of pH values. Zeta potential analysis revealed that the electrostatic repulsion between anionic dyes decreased after the addition of BT-TWB10 and further diminished by adjusting the reaction mixture to pH2 before flocculation, suggesting the occurrence of adsorption bridging and charge neutralization. These findings proposed that BF-TWB10 might be a promising bioflocculant for the removal of dyes in textile wastewater. PRACTITIONER POINTS: Bioflocculant BF-TWB10 shows outstanding performance in flocculation. Adsorption process follows pseudo-second-order kinetic model. Flocculation process is pH-responsive. High-temperature pretreatment or divalent cations enhance its flocculation performance. The analyses suggest the occurrence of charge neutralization and adsorption bridging.

Anaerobic-aerobic treatment of high-strength and recalcitrant textile dyeing effluents

Eco-friendly treatment of complex textile and dyeing wastewaters poses a pressing environmental concern. An approach adopting different treatment paths and integrated anaerobic–aerobic processes for high-strength and recalcitrant textile dyeing wastewater was examined. The study demonstrated that over 97% of suspended solids (SS) and more than 70% of chemical oxygen demand (COD) were removed by polyaluminum chloride pre-coagulation of suede fabric dyeing stream. Up to 58% of COD and 83% of SS were removed through hydrolysis pretreatment of other low-strength streams. Notable COD removal of up to 99% from a feed of 20,862 mg COD/L was achieved by integrated anaerobic–aerobic treatment of high strength stream. Besides achieving high COD removal of 97%, the anaerobic granular sludge process demonstrated multi-faceted attributes, including high feed loading, smaller footprint, little sludge production, and good stability. The integrated anaerobic–aerobic treatment offers a robust and viable option for highly contaminated and recalcitrant textile dyeing wastewater.

Evaluation of Different Reverse Osmosis Membranes for Textile Dyeing and Finishing Wastewater Reuse

Different commercial reverse osmosis (RO) membranes from Vontron and DuPont Filmtec were evaluated for textile dyeing and finishing wastewater (TDFW) reuse in China. All six tested RO membranes produced qualified permeate meeting TDFW reuse standards at a water recovery ratio (WRR) of 70% in single batch tests. The rapid decline of apparent specific flux at WRR over 50% was mainly ascribed to feed osmotic pressure increase caused by concentrating effects. Multiple batch tests using Vontron HOR and DuPont Filmtec BW RO membranes with comparable permeability and selectivity demonstrated the reproducibility and showed low fouling development. The occurrence of carbonate scaling on both RO membranes was identified by scanning electron microscopy and energy disperse spectroscopy. No obvious organic fouling was detected on both RO membranes by attenuated total reflectance Fourier transform infrared spectrometry. From the orthogonal tests, with an integrated RO membrane performance index (i.e., 25% rejection ratio of total organic carbon + 25% rejection ratio of conductivity + 50% flux ratio of final to initial) as a target, the optimal parameters were determined as WRR of 60%, cross-flow velocity (CFV) of 1.0 m/s, temperature (T) of 20 °C for both RO membranes, while trans-membrane pressures (TMP) of 2 and 4 MPa were optimal for Vontron HOR RO membrane and DuPont Filmtec BW RO membrane, respectively. Both RO membranes with the optimal parameters produced good permeate quality for TDFW reuse and kept a high flux ratio of final to initial, demonstrating the effectiveness of the orthogonal tests.

Environmental Remediation of Real Textile Dyeing Wastewater Under Visible Light and Inactivation of Pathogenic Bacteria Using ZnO/CuO Nano‐Needles

Textile industries have an immense existence in a country's economy. Large quantity of water is consumed by textile dyeing industries and produces volumes of wastewater. Treating these hazardous effluents to make them environmental friendly, using nanocatalysts is the best promising method. Metal oxide nanomaterials have emerged as an important tool for environmental remediation. Herein the hydrothermally synthesized ecofriendly and low‐cost zinc oxide/copper oxide nanocomposites (ZnO/CuO NCs) with different proportions of binary oxides are evaluated for the applications of degrading organic pollutants and antibacterial activity. The influence of doping is also studied in structural, optical, morphological, photocatalytic, and antibacterial activities. The presence of CuO in NCs affirms the formation of ZnO/CuO NCs. Photodegradation of Congo Red (CR) and real textile dyeing wastewater (TDW) under visible light irradiation by 0.5 M ZnO:0.5 M CuO NCs reveal them to act as a perfect catalyst by tuning doping concentration of Cu in ZnO, with 1.9 × 10−3 and 5.4 × 10−3 M min−1 rate constant. Hybrid nanocomposite materials exhibit high antibacterial activity against Staphylococcus aureus and Escherichia coli with 5 and 6 mm inhibition zone. The experimental characteristics of NCs are explained by a combination of electronic band structure due to size effect and tuning metal oxide proportions in comparison to that of pure metal oxide.

The synthesization of activated carbon from electrocoagulated palm oil mill effluent sludge for wastewater treatment

The oil palm industry in Malaysia is certainly the one of economic and agricultural drives for the country. Nevertheless, despite the obvious benefits that it possesses, oil palm mill also significantly contributes to environmental degradation. It generates massive amounts of solid waste, wastewater, and air pollution from its production and processing processes. Activated carbon (AC) as an adsorbent has been used widely to remove pollutants in wastewater. Many attempts have been made to produce economically accessible AC. This paper explores the idea of producing an AC, a value-added product, sludge produced from the electrocoagulation process of palm oil mill effluents (POME) through chemical activation. AC has different applications after its discovery as a solid and reliable adsorbent. Its microporous structure, high surface reactivity, and surface area make it versatile and viable for removing pollutants from aqueous solutions. The electrocoagulated sludge-based AC is characterized by its surface characteristics, elemental compositions, surface morphology, and available functional group. To validate the adsorption capacity of electrocoagulated sludge-based AC, textile dye wastewater treatment was carried out to test the efficiency of AC. Results indicate that TSS in textile dye wastewater decreased as the adsorbent dosage increased. The values of TSS removal by AC from H3PO4 activation decreased steadily compared to KOH activation. Meanwhile, the color removal percentage decreased when the dye concentration increased. AC from H3PO4 activation has higher color removal percentage. This shows that AC from H3PO4 activation has better adsorption due to its more extensive surface area. From BET analysis, AC by H3PO4 activation offers a higher surface area, 36.1017 m2/g, compared than KOH activation, 8.9460 m2/g. Extensive surface area has a higher tendency to adsorb contaminations. The findings of this work confirmed the potential use of electrocoagulated sludge-based AC as an alternative and economically adsorbent for effective dye pollution removal in wastewater.

Treatment of textile dyeing wastewater using a low-cost adsorbent

A cost-effective adsorbent was synthesized from Eichhornia Crassipes using phosphoric acid as an activating agent and it was applied for the decolourization of the Textile dyeing industry’s effluent (TDE). Physical, chemical and morphologic characteristics were investigated using characterization studies, BET and XRD techniques. Batch experiments were performed to determine the optimum dosage, temperature, time and pH. The ideal conditions for treating TDE were found to be 30 °C, 1 g/L dose, 90 min, and pH 7. Maximum decolourization of 92%, reduction of COD and BOD were found to be 66.77% and 83.94% respectively with 50 T TDE. As a result, the aquatic weed Eichhornia crassipes can be employed as an efficient adsorbent to remove dye from wastewater.

Plant-microbe-dye interaction during rhizoremediation

The conventional technologies used for textile dye wastewater treatment are costly, and involve high energy consumption and sludge production. However, bioremediation using plants and microbes involves low cost, energy consumption, and no sludge formation. Hence, the review focuses on the dye degradation by the plant-microbe treatment system.

Decolourisation of Real Industrial and Synthetic Textile Dye Wastewater Using Activated Dolomite

Textile effluent accounts for 22% of the total industrial wastewater produced in Malaysia. Due to their ubiquitous use in organic dyes, inefficiently treated textile wastewaters pose environmental and health hazards. Colour, chemical oxygen demand, biochemical oxygen demand, toxic metals and microbes are the commonly targeted water quality parameters in untreated textile fluids. Furthermore, their non-biodegradability and high colour intensity may reduce aquatic diversity by blocking the sunlight. Recently, physical treatment, principally adsorption, has been conducted. Dolomite has additional features, such as performing as a heavy metal and microbe remover. This study employed dolomite for treating textile dye wastewater from a commercial textile manufacturer and synthetic effluent containing methyl orange. Different sizes of dolomite were activated at different temperatures and subsequently added to the water samples in varying amounts. After 2 h of agitation at 100 rpm and sedimentation for 24 h, their absorbance reading was taken. Their morphological, decolourisation percentage, chemical oxygen demand reduction percentage and bacterial growth post-treatment were examined. Despite variances in dolomite’s capacity to decolourise colours, the treatment proved effective in decolourising dyes, removing chemical oxygen demand and reducing bacterial growth. The most significant percentages of decolourisation observed were 98.7% for real textile dye wastewater (RTDW) and 78.0% for synthetic textile dye wastewater (STDW), while for chemical oxygen demand, reductions were 66.7% for RTDW and 73.9% for STDW, respectively. As for microbe growth inhibition, the highest growth reduction percentages were 99.7% and 98.6% for RTDW and STDW, respectively.