Color Reduction Research Articles

Treatment of real textile effluent containing indigo blue dye by hybrid system combining adsorption and membrane processes

The rapid expansion of the textile industry in Tunisia has resulted in ever-increasing discharges of wastewater, making it necessary to set up treatment systems allowing i) its discharge into the environment or ii) to recycle the water in the textile plant. In this study, several unitary operations were tested in order to improve the treated water quality. Thus, the following unit operations were applied: adsorption using Natural Clay (NC) and Powdered Activated Carbon (PAC), ultrafiltration (UF) and nanofiltration (NF) individually or in synergy: UF, nanofiltration, PAC-UF, NC-UF, UF-NF et Adsorption-UF/NF. The experiments were carried out on real textile effluent containing Indigo blue dye. A threshold concentration was observed above which performance no longer increases. NF alone showed better reduction of COD (67%), color (78%), and turbidity (98%) than UF alone (26%, 48%, 95%, respectively). The coupling UF–NF showed a clear improvement in water quality in terms of color (99%) and COD (98%) with an improvement in the NF flux from 67.81 L/h.m2 to 90.62 L/h.m2. No fouling was observed for NF while it is significant during UF. The used of adsorption as pretreatment to filtration leads to an enhancement of the treatment performances with a removal of 99.9%, 99.5% and 79.5% respectively for turbidity, color and COD for NC-UF and a removal of 100%, 99.4% and 79.6% respectively for turbidity, color and COD for PAC-UF. Moreover, the addition of adsorbent controls the fouling and a constant and high flux is quickly attained and remains stable over time. The use of natural clay as adsorbent represents an economically profitable solution since it can be obtained locally and the clay used can be reused in the ceramic industry as an additive for road surfacing without the need for regeneration.

Evaluation of Fall and Winter Trinexapac-ethyl Applications on Ultradwarf Bermudagrass Putting Green Color, Quality, and Green Cover

Ultradwarf bermudagrass (UDB) putting greens grown in subtropical and temperate climates can face elevated risk of winter injury from cold temperatures. Trinexapac-ethyl (TE) inhibits UDB growth potentially reducing spring green-up and overexertion of carbohydrate reserves for UDB during the cold de-acclimation period. A field study was conducted to determine the effect of fall and winter TE applications on the visual quality and color of UDB putting greens in Virginia from the cold acclimation phase through the cold de-acclimation phase. A second controlled-environment study was conducted to determine how TE applications to UDB during cold acclimation affected UDB cold tolerance. In the first study, plots were treated with 0.026 kg⋅ha−1 a.i. every 14 days, 0.013 kg⋅ha−1 a.i. every 14 days, or 0.013 kg⋅ha−1 a.i. every 7 days either in the fall only or in the fall and winter. A nontreated control was included for comparison. For the second study, cup-cutter plugs (10.8-cm diameter) of UDB were treated with 0.026 kg⋅ha−1 a.i. every 14 days from the time growth resumed after green-up through cold acclimation or not treated with TE. Plugs were then exposed to −9.4 °C for 4, 6, 8, or 10 hours and placed into a greenhouse to green up. The GC50 values (exposure time to reduce bermudagrass green cover by 50% 6 days after exposure to −9.4 °C) for the treatments were then calculated based on exposure time and percent green-up. In the first study, TE applications improved UDB quality >3.8%. However, TE applications reduced UDB color, and trends exhibited this reduction in color particularly during the late cold acclimation, winter dormancy, and early cold de-acclimation phases. In the second study, TE applications reduced GC50 values by >10.9% compared with nontreated plugs, suggesting TE reduces UDB cold tolerance during the cold acclimation phase.

Catalytic thermal treatment (catalytic thermolysis) of textile dyeing effluent

During the production of textiles a large amount of wastewater is generated that contains high organics load and color appearance. If it is directly (untreated) discharged into any water-receiving body then it gets fully contaminated, hence its proper treatment is required. The present study deals with the treatment of textile dyeing effluent (TDE) using catalytic thermolysis (CT) for the reduction of color and COD reduction with the help of CuO as a catalyst. The catalyst (CuO) was prepared successfully on the laboratory scale. The CuO preparation is done by alkali precipitation of copper sulfate followed by drying and calcination. Catalyst is characterized in detail including X-ray diffraction, SEM, and TEM analysis. CT treatment of TDE was carried out in a 0.5 dm3 thermolysis batch reactor using CuO as a catalyst at different pH (2.4–10.4), temperatures (70 °C–115 °C), and catalyst loadings (1.5–5.5 g/dm3). The maximum 72 % COD reduction was achieved at the optimum condition of 70 °C temperature, catalyst loading of 1.5 g/dm3, and 4.4 pH. The residues obtained after CT were characterized by TGA, TDA, and TG. In addition, settling characteristics were also observed for CT-treated sludge at different temperatures. CT is a novel treatment technique to treat highly polluted wastewater. During the CT treatment, the addition of chemicals is not required and it has good removal efficiency. Further CT-treated sludge has good heating value hence it can be used as an industrial fuel. In other words, no secondary pollutants are generated during the CT process.

Development of an antimicrobial, 3D printable denture base material with K18 quaternary ammonium silane-functionalized methyl methacrylate and filler

Statement of problemDenture base materials are highly susceptible to microbial colonization, which can lead to denture stomatitis. In addition, patients who sleep with their dentures have an increased chance of contracting pneumonia. Commercially available antimicrobial denture base materials to prevent or combat microbial colonization are lacking. PurposeThe purpose of this in vitro study was to determine the effects of K18 quaternary ammonium methacryloxy silane-functionalized filler (K18-Filler) and methyl methacrylate (K18-MMA) on the polymerization of 3D printed denture base material and its esthetic, mechanical, and antimicrobial properties. Material and methodsK18-Filler (0%, 10%, 20% w/w) and K18-MMA (0%, 5%, 12.5% w/w) were added to a 3D printable denture base resin (Denture Base Resin, Original Pink; Formlabs Inc) and 3D printed. Specimens were tested by using the Rockwell15T hardness, near infrared FTIR monomer-to-polymer degree of conversion (DoC), transparency parameter (TP), color shift, and 3-point bend and by counting colony forming units against Streptococcus aureus, Streptococcus sanguinis and Candida albicans tests. Data were analyzed using analysis of variance with the Tukey-Kramer HSD post hoc test. ResultsControl resins had significantly higher Rockwell15T hardness than most of the K18 groups (P<.05) but had comparable DoC with all K18 groups except one, showing that all groups were well polymerized. Controls had significantly higher TP than most K18 groups, but most K18 groups had ΔE<3.3, so the color shift was not noticeable. However, the 12.5% K18-MMA with 10% and 20% K18-Filler groups, which were also the groups used to test for antimicrobial activity, had ΔE>8. All K18 groups had comparable or greater moduli than the controls, but the controls had significantly higher ultimate transverse strengths than most K18 groups (P<.05). All 12.5% K18-MMA with K18-Filler groups had significant antimicrobial activity against S. aureus, S. sanguinis, and C. albicans. Conclusions12.5% K18-MMA and K18-Filler produced 3D printable denture materials with comparable polymerization properties and significant antimicrobial properties against S. mutans, S. sanguinis, and C. albicans. High K18-MMA and K18-Filler concentrations caused significant color shifts and reductions in ultimate strengths.

A Study of the Effects of Alum and PAC on the Coagulation Process of Dug Well Water

The local population of Pal IX Village in West Kalimantan heavily depends on dug wells as their main source of obtaining clean water. The prolonged consumption of elevated concentrations of manganese (Mn) and iron (Fe) in water sourced from dug wells have neurotoxic effects on both adults and children. Therefore, it is imperative to employ alum and PAC coagulants for the treatment of dug well water in order to comply with the established national quality standard. However, the utilization of both coagulants resulted in elevation in the levels of iron (Fe), hence restricting the capacity to satisfy the quality standards. An augmentation in the mass of the coagulant is associated with a decline in the reduction efficiency. It is indicated that utilizing a mass of 0.5 grams of alum coagulant is the most favorable choice, resulting in a reduced of 50.14% for total dissolved solids (TDS), 86.25% for color, 97.70% for turbidity, and 94.48% for the concentration of Mn metal. By PAC coagulant, it has been determined that an ideal coagulant mass of 0.5 gram produces favorable outcomes with a TDS reduction of 45.08%, a color reduction of 97.71%, a turbidity reduction of 97.22%, and a Mn reduction of 95.04%.

Combination of pozzolan and sawdust as biofilter for textile wastewater treatment

Background: Inappropriate management of textile wastewater results in environmental pollution. To counter this, biofilters or biofilm systems serve as alternatives. Biofilters work like a filter, with a media stack that aids in the filtration process. In this study, pozzolan and sawdust were used as media. The present study aimed to identify the difference in average color content, chemical oxygen demand (COD), and chromium of textile wastewater after passing through a single biofilter versus a combination biofilter. Methods: This study employs a post-test with a control design experimental research design. The research population is the total textile wastewater produced by the X industry located in Cimahi city, Indonesia. The grab sampling technique was employed to collect 30 L of textile wastewater for each treatment using both the single biofilter (composed solely of sawdust) and the combination biofilter (mixture of sawdust and pozzolan). Results: There are significant differences in color, COD, and chromium content averages between single and combined biofilter treatments, supported by P values of 0.012, 0.004, and 0.010. The single biofilter exhibited higher percentage reductions in color and chromium (14.25% and 90.83%, respectively) compared to the combination biofilter. In contrast, the combination biofilter achieved a remarkable COD reduction of up to 79.45%compared to the single biofilter. Conclusion: The results of the present study showed that the single biofilter had a higher capacity to remove color and chromium compared to the combination biofilter. Meanwhile, the combination biofilter was found to be more effective in removing COD compared to the single biofilter.

Photocatalytic degradation of methyl orange in water using oyster shell-derived calcium oxide nanoparticles

In response to the Philippine-textile-industry goal of adapting sustainable waste management practices, oyster shells as abundant waste, can be valorized for photocatalytic wastewater treatment. Moreover, aeration and water quality as lesser-known parameters were assessed. Here, a nano-sized calcium oxide (CaO NP) photocatalyst from oyster shells was prepared with a 57 % CaO yield. Instrumental characterization confirmed its nanoparticle size, elemental composition, and narrow bandgap, which favor adsorption-photodegradation. The optimum photocatalyst dose achieved 93.7 % removal efficiency and was significantly maximized to 98.5 % under aerated conditions. CaO NP is reusable with stable performance and has first-order dye degradation kinetics. Aerated photocatalytic treatment of simulated wastewater showed a significant reduction in color and chemical oxygen demand with acceptable final pH. Furthermore, the treated wastewater is dischargeable to Class C waters by Philippine environmental standards, proving its successful remediation and application as a dispersible and recyclable photocatalyst for removing methyl orange in water.

Mycoremediation of Synthetic Azo Dyes by White-Rot Fungi Grown on Diary Waste: A Step toward Sustainable and Circular Bioeconomy

This study assesses the efficacy of three white-rot fungi—Bjerkandera adusta, Phanerochaete chrysosporium, and Trametes versicolor—in degrading synthetic dyes and lignin in pulp and paper mill effluents, which annually contribute around 40,000 million cubic meters of dyed waste. Exploiting the structural resemblance of dyes to lignin, the fungi utilize ligninolytic enzymes—lignin peroxidase, manganese peroxidase, and laccase—to break down the pollutants. Initial mycoremediation trials in synthetic dye solutions with Direct black 80, Direct yellow 11, Basic brown 1, Orange II, and Red 8 BLP achieved decolorization rates of 70–80% within 7 days, except for Red 8 BLP. Both soluble and insoluble lignin fractions were significantly reduced, with an overall removal rate of 80–90%. Contrary to prior beliefs about the recalcitrance of azo dyes, B. adusta demonstrated substantial biodegradation capabilities, even on non-lignocellulosic substrates, such as dairy waste. The decolorization efficacy varied with dye structure, suggesting that efficiency should not be judged solely on color reduction. Remarkably, B. adusta also effectively decolorized and removed lignin from actual mill effluents without pH alteration, indicating a viable low-cost bioremediation strategy. This invites further investigation into optimizing B. adusta for industrial wastewater biodecolorization, especially in the field of PAHs (Polycyclic Aromatic Hydrocarbons) and EDCs (Endocrine Disrupting Chemicals).

Effects of the physical structure and surface charge of activated carbon on the reduction of biogenic amines in anchovy fish sauce

This study aimed to efficiently reduce a large number of biogenic amines in salt-fermented fish sauce while minimizing sensory reduction using various activated carbons. Aromatic amines, such as tryptamine and phenethylamine, were reduced by 86.1–100 % after treating with activated carbon. Histamine with a heterocyclic structure decreased by 13–42 %. No significant effects were observed on the levels of aliphatic amines, putrescine, cadaverine, spermine, and spermidine. The major taste component, amino acid nitrogen, was reduced to within 3 %, and brown color removal was reduced depending on the type of activated carbon used. Acid-modified AC-A and AC-B had rough surfaces, high total acidity, low point of zero charge (pHpzc), and rich surface functional groups. Owing to its smooth surface, low total acidity, high pHpzc, and few surface functional groups, AC-C exhibited a higher histamine elimination and less color reduction despite its lower surface area compared to other activated carbons.

Development of technology for refining of black cotton oil miscella

The study focusing on the forrafination process of black miscella in cottonseed oil has yielded promising results, showcasing several significant improvements in the overall oil refining process. Notably, the forrafination method has demonstrated its effectiveness in enhancing both yield and the quality of the refined oil. One notable outcome of the study is the substantial increase in yield achieved through the forrafination process. This implies that the method is efficient in extracting a higher quantity of refined oil from the black miscella of cottonseed oil compared to traditional refining methods. Furthermore, the forrafination process has proven effective in reducing the color of the refined oil. This is a critical improvement, as color is often an important quality parameter in the food industry, influencing the aesthetic appeal of the oil and its suitability for various applications. A significant benefit highlighted in the study is the reduction in the consumption of caustic soda during the refining process. This is economically and environmentally advantageous, as it reflects a more resource-efficient approach to oil refining, aligning with sustainability goals. Importantly, the refined oil obtained through forrafination meets the standard requirements for both acid number and color. This is a key validation of the method's success, indicating that the refined oil is not only produced in higher quantities but also adheres to the established quality standards, ensuring its suitability for various applications. The study's findings on forrafination in the black miscella of cottonseed oil represent a noteworthy advancement in the field of oil refining. The demonstrated improvements in yield, color reduction, and reduced consumption of caustic soda contribute to more efficient and sustainable processes, with the refined oil meeting industry standards for quality.

Efficacy and safety of diode laser for facial hair reduction in hirsutism-a clinico-trichoscopic evaluation.

Hirsutism is the presence of excessive terminal hair on androgen-dependent sites of the body. Lasers like Alexandrite, diode, and Nd:Yag lasers have been used for hair reduction with varying efficacy. Trichoscopy of hair is a simple noninvasive method of hair assessment. However, it has not been used in the assessment of diode laser hair reduction. This study aimed to assess the efficacy and safety of diode laser hair reduction in skin color with the help of clinical and trichoscopic assessment. This prospective observational study included 73 patients of hirsutism recruited in 18-month period. All participants received sessions of 805 nm diode laser at monthly intervals up to six sessions. Clinical and trichoscopic evaluation along with photographs were obtained at each visit. Side effects, if any, were noted in every sitting. All patients were females of Fitzpatrick skin types III-V. All clinical parameters showed statistically significant hair reduction when compared with baseline. Trichoscopic parameters of hair reduction like total hair count, terminal hair count, and terminal/vellus hair ratio showed reduction compared to baseline which was statistically significant (P < 0.05). The most common side effect noted in our study was pain followed by erythema and perifollicular edema. Diode laser is an effective and safe procedure for the reduction of unwanted facial hair, even in darker skin types. We also wish to emphasize that trichoscopy for the assessment of laser hair reduction is a recent, noninvasive, simple, and underutilized tool. No serious adverse events were noted in our study.

Subcritical water digestion of woody biomass: extraction of cellulose nanomaterials under acid-lean condition.

Subcritical water extraction (SWE) is an emerging green and efficient hydrothermal technology, that offers superior performance in active material extraction, scalability, and reduction of harsh process chemicals, in biomass conversion. Regarding biomaterials, traditional isolation methods for cellulose nanocrystals (CNCs) are reliant on harsh chemicals (i.e., strong acid), which are expensive with little to no recyclability. This paper explores SWE as a nanotechnology platform to produce CNCs under the principle of "less is more" - by using low content (1 wt%) of phosphoric acid under subcritical conditions. Acid-catalyzed digestion of woody biomass afforded CNCs desirable physico-chemical features that are dependent on the process parameters (temperature, pressure, and time). Process temperature had a major impact on the reduction of fiber sizes (macroscale to nanoscale), fiber degradation, and fiber coloration (white to black). Electron microscopy revealed rod-like structures, with varying particle size distribution (100-500 nm), dominated by process time. However, colloidal stability was low (versus acid-hydrolyzed CNCs) due to the low charges on the surface of CNCs. Interestingly, vibrational spectroscopy reveals the effect of process pressure on biomass conversion to CNCs (with cellulose I structure) evidenced by Raman spectroscopy and solid-state fluorometry. The produced (bio)nanomaterials possessed a degree of crystallinity (∼70%) comparable to those produced via acid hydrolysis, with higher thermal stability, enhancing their applicability over a wide range of heat-intensive processes required for nanocomposite applications in biomedical and automotive industries, among others.

Colorimetria e propriedades químicas da madeira de Parkia pendula e Simarouba amara modificada termicamente

ABSTRACT The thermal modification of wood is a process that alters its chemical composition, aiming to improve technological properties such as dimensional stability, reduction of equilibrium moisture content, homogeneity, or color. In this context, this study aimed to evaluate the colorimetry and chemical properties of the wood of Parkia pendula (angelim-saia) and Simarouba amara (marupá) that was thermally modified by different methods. Three treatments were evaluated: T1 (pre-treatment in an oven for one hour at 120 °C and treatment in an oven at 180 °C for three hours); T2 (pre-treatment in an autoclave at 125 °C for three hours under 1.2 kgf cm-2 and treatment in an oven at 180 °C for three hours); and T3 (without pre-treatment, with sample treatment in vegetable oil). The thermally modified wood was evaluated in relation to untreated wood for structural chemical composition (extractives, lignin, holocellulose and ash content), colorimetric parameters defined through the CIELAB (Commission Internationale de l´Eclairage) system and total color variation. We detected a significant increase in extractives content and a decrease in holocellulose and lignin content in T3 for both species, which can be explained by the impregnation of oil in the wood samples. The thermal modification caused the surface darkening of the wood of both species, which was more pronounced in P. pendula. Despite the colorimetric change, there was no chemical damage to the wood.

Performance evaluation of gravity-driven bioreactor (GDB) for simultaneous treatment of black liquor and domestic wastewater.

A lab-scale gravity-driven bioreactor (GDB) was designed and constructed to evaluate the simultaneous treatment of black liquor and domestic wastewater. The GDB was operated with a mixture of black liquor and domestic wastewater at a ratio of 1:1 and maintained at an average organic loading rate of 1235mg-COD/L-Day. The wastewater was fed to the primary sedimentation tank at a flow rate of approximately 12mL/min and subsequently passed through serially connected anaerobic and aerobic chambers with the same flow rate. Each wastewater sample was allowed to undergo a hydraulic retention time of approximately 72h, ensuring effective treatment. The GDB was actively operated for nine samples (W1-W9) at a weekly frequency. The entire process was conducted within the workstation's ambient temperature range of 30-35°C to sustain microbial activity and treatment efficiency in an open environment. The performance of the GDB was evaluated in terms of various pollution indicators, including COD, BOD5, lignin removal, TDS, TSS, EC, PO43-, SO42-, microbial load (CFU/mL and MPN index), total nitrogen, and color reduction. The results showed that the GDB achieved promising treatment efficiencies: 84.5% for COD, 71.80% for BOD5, 82.8% for TDS, 100% for TSS, 74.71% for E.C., 67.25% for PO43-, 81% for SO42-, and 69.36% for TN. Additionally, about 80% reduction in lignin content and 57% color reduction were observed after the treatment. The GDB substantially reduced microbial load in CFU/mL (77.98%) and MPN (90%). This study marks the first to report on wastewater treatment from two different sources (black liquor and domestic wastewater) using a simple GDB design. Furthermore, it highlights the GDB's potential as a cost-effective, environmentally friendly, and efficient solution for wastewater treatment, with no need for supplementary chemical or physical agents and zero operational costs.

Microbial Degradation Of Calcium Oxalate And Its Potential Application

Calcium oxalate is a naturally occurring compound found in various plants and minerals, and its accumulation in the kidney leads to the formation of kidney stones in humans. One of the main causes of kidney stone formation is a decrease in the number of intestinal microbiota which are capable of degrading calcium oxalate. This study focuses on bacterial degradation of calcium oxalate accumulated in humans. Searching for Calcium oxalate degrading strain with high degrading activity has become one of the priorities from the context of research. The study aimed to isolate and characterize microorganisms which are capable of degrading calcium oxalate. Calcium oxalate degrading microorganisms were isolated from faecal samples by using MRS-calcium oxalate medium. Calcium oxalate degrading bacteria were identified on the basis of colour reduction on calcium oxalate medium plate after the incubation period. The morphological and biochemical characterization of isolates were studied. Quantitative determination of degradation was performed by using an indole assay. The activity of isolates was observed by the degradation of kidney stones. Isolates showed better results for degradation of kidney stones after 2 weeks of the incubation period.

BUNGA MATAHARI DALAM KARYA SENI GRAFIS CETAK TINGGI

The purpose of creating this final work is as a form of aesthetic experience when the author needs calm in living his life. Sunflowers have a philosophy of always following the direction of the sun’s rays, which means being loyal, optimistic and enthusiastic so that sunflowers can be used as an inspiration for those who see them. The issues discussed are: 1) What is interesting about sunflowers as a source of ideas for creating high-print graphic art works, 2) How sunflowers become a theme in high-print graphic art works, 3) How to visualize sunflowers in high-print graphic art works . The objectives of creating this thesis work are: 1) Describe the interesting things about sunflowers, 2) Explain the choice of sunflowers as a source of ideas for creating graphic works of art, 3) Create a visualization of sunflowers as a work of graphic art. Sunflowers are packaged in high-print graphic art visuals with a flow of surrealism and color reduction methods. Presentation of works with figures using matte glass so as not to reflect light. The media used is mdf with a thickness of 3 mm with dimensions of 60 cm x 80 cm. The work is presented by placing it on the surface of the gallery wall using glass figures. Hopefully this work of art can be a reference, useful and enjoyable for the community.

Distributed Graph Coloring Made Easy

In this article, we present a deterministic \(\mathsf {CONGEST}\) algorithm to compute an O ( k Δ)-vertex coloring in O (Δ / k )+log * n rounds, where Δ is the maximum degree of the network graph and k ≥ 1 can be freely chosen. The algorithm is extremely simple: each node locally computes a sequence of colors and then it tries colors from the sequence in batches of size k . Our algorithm subsumes many important results in the history of distributed graph coloring as special cases, including Linial’s color reduction [Linial, FOCS’87], the celebrated locally iterative algorithm from [Barenboim, Elkin, Goldenberg, PODC’18], and various algorithms to compute defective and arbdefective colorings. Our algorithm can smoothly scale between several of these previous results and also simplifies the state-of-the-art (Δ +1)-coloring algorithm. At the cost of losing some of the algorithm’s simplicity we also provide a O ( k Δ)-coloring algorithm in \(O(\sqrt {\Delta /k})+\log ^{*} n\) rounds. We also provide improved deterministic algorithms for ruling sets, and, additionally, we provide a tight characterization for one-round color reduction algorithms.

Optimizing Distillery Effluent Treatment through Sono-Electrocoagulation: A Response Surface Methodology Approach

This work is an effort to remediate rice grain-based biodigester effluent (BDE) by applying the sono-electrocoagulation (SEC) process using Iron as a sacrificial electrode to accomplish this process. A batch reactor is used for the investigation. The effect of the SEC process on the reduction of chemical oxygen demand (COD) and color from the wastewater was studied by varying operating parameters including ultrasonic power (U), current density (j), initial pH (pHi), and electrolysis time (t) in the ranges of 20-60 W, 49.5-247.5 A/m2, 2-10 and 12-60 minutes respectively. The results obtained were optimized by using central composite design (CCD) which is a special feature of the response surface method (RSM). This tool is well applicable in the SEC process to explores the relationships between different varying operating parameters with two responses namely COD and color removal efficiency. The RSM is to use a sequence of designed experiments to obtain an optimal response. The analysis demonstrated that the quadratic regression model fitted well with SEC-generated data. Moreover, no significant difference was found between experimental and predicted data. The coefficient of determination (R2) of 0.9995 and 0.9895 were observed for COD and color removal efficiency. Results indicated that the COD removal efficiency of 93% and color removal efficiency of 88% were found at optimum conditions U of 50, J of 198 A/m2, pHi of 7, and t of 48 minutes.

The Influence of Electrode Plate Area in Reducing Turbidity and Color Levels in Peat Water

Peat water generally exhibits characteristics ranging from dark brown to black, with high organic content and a pH range between 3.7 and 5.3. These features pose challenges in meeting clean water quality standards, essential for maintaining human health. Consequently, the treatment of peat water becomes a pressing need to enhance its quality for suitable use. Electrocoagulation has emerged as a widely applied method in peat water treatment. This research aims to evaluate the influence of electrode plate area and contact time in reducing turbidity and color in peat water. The research methodology employed a quasi-experimental design known as the One-Group Pretest-Posttest. Thirty test samples were collected with variations in electrode plate areas of 4 x 30 cm, 5 x 30 cm, and 6 x 30 cm. Contact time was varied within the range of 30, 60, 90, 120, and 150 minutes, applying a voltage of 48 volts. The results indicated fluctuations in the increase of turbidity in peat water after the electrocoagulation treatment. A plate area of 6 x 30 cm led to a turbidity increase of 27.33 NTU or approximately 83% after a contact time of 150 minutes. Meanwhile, the color level in peat water decreased by 65 TCU with a 5 x 30 cm electrode plate area after 150 minutes of contact time, achieving an effectiveness of 90% in color reduction. In conclusion, the electrode plate area significantly influences the reduction of turbidity and color in peat water. Although there is no discernible effect of contact time on turbidity levels, prolonged contact time has a significant impact on reducing the color level in peat water.

Optimization of laccase from Stenotrophomonas maltophilia E1 by submerge fermentation using coconut husk with its detoxification and biodecolorization ability of synthetic dyes

Enzymatic degradation of synthetic dyes holds an immense promise for addressing the environmental concerns associated with the textile and dye industries. This study aimed to isolate bacteria capable of producing laccase enzymes from an anthropogenic environment. Subsequently, viability of utilizing cost-effective agricultural residues as substrates for laccase production was assessed. Response Surface Methodology (RSM) and the One Variable at a Time (OVAT) approach was pursued for the optimization of laccase production, followed by pH and temperature stability, dye degradation and decolorization experiments, toxicological studies on the degraded dye metabolites. In results, laccase-producing bacterial strain was identified as Stenotrophomonas maltophilia strain E1 (S. maltophilia). Among variety of substrates, coconut husk exhibited optimal efficacy. In a statistical optimization study, it was found that S. maltophilia was capable of producing laccase 51.38 IU/mL, i.e., three times higher than the amount of laccase produced by unoptimized medium (16.7 IU/mL), and the enzyme activity was found to be steady at an acidic pH, and a mesophilic temperature range. The laccase obtained from S. maltophilia E1 demonstrated proficient dye decolorization capabilities, achieving a notable 92.1% reduction in Malachite green dye coloration at a concentration of 500 ppm. Gas chromatography–mass spectrometry (GC–MS) analysis of the decolorized derivatives of Malachite green revealed a conversion into a distinct compounds. Moreover, after undergoing laccase treatment, Malachite green exhibited decreased phytotoxic effects on Oryza sativa, pointing to enzymatic detoxification. Collectively, insights gained from the present study will contribute to the development of efficient enzymatic approaches for addressing the environmental pollution caused by synthetic dyes.Graphical