Valorization of citrus peel industrial wastes for facile extraction of extractives, pectin, and cellulose nanocrystals through ultrasonication: An in-depth investigation.

In this work we developed an eco-friendly valorisation of Citrus wastes (CWs), through a solvent-assisted ultrasonication extraction technique, thus having access to a wide range of bio-active compounds and polysaccharides, extremely useful in different industrial sectors (food, cosmetics, nutraceutical). Water-based low-amplitude ultrasonication was examined as a potential method for pectin extraction as well as polar and non-polar citrus extractives (CEs), among which hesperidin and triglycerides of 18 carbon fatty acids were found to be the most representative ones. In addition, citric acid:glycerol (1:4)-based deep eutectic solvent (DES) in combination with ultrasonic extraction was utilized to extract microcellulose (CMC), from which stable cellulose nanocrystals (CNCs) with glycerol-assisted high amplitude ultrasonication were obtained. The physical and chemical properties of the extracted polysaccharides (pectin, micro and nanocellulose) were analysed through DLS, ζ-potential, XRD, HP-SEC, SEM, AFM, TGA-DSC, FTIR, NMR, and PMP-HPLC analyses. The putative structure of the extracted citrus pectin (CP) was analysed and elucidated through enzyme-assisted hydrolysis in correlation with ESI-MS and monosaccharide composition. The developed extraction methods are expected to influence the industrial process for the valorisation of CWs and implement the circular bio-economy.

Source reduction and end treatment of acid mine drainage in closed coal mines of the Yudong River Basin.

After the closure of the Yudong coal mine, the pH value was approximately 3.0, and the Fe and Mn concentrations reached 380 and 69 mg/L, respectively, in the acid mine drainage (AMD), causing serious pollution to the water bodies in the nearby watershed. Combined with the formation conditions of AMD, the comprehensive treatment technology of source reduction-end treatment is adopted to treat the AMD. The treatment area of the goaf is 0.3 km3, the filling and grouting volume is about 6.7 m3, and the curtain grouting volume is 4,000 m3. Through the grouting and sealing treatment in the goaf, the water volume is reduced to less than 85% of the initial volume (100 m3/h). After the end treatment, the pH value of the effluent is around 7.0, the content of Fe and Mn is less than 0.1 mg/L, and the removal rate is above 99%. The project was subsequently operated at RMB 0.85 yuan/t. This project is aimed at the treatment of AMD from small coal mines in complex terrain conditions. It has the characteristics of low cost and high efficiency and can provide an effective treatment technology for AMD in southwestern China and areas with the same geological conditions.

Impact of untreated tannery wastewater in the evolution of multidrug-resistant bacteria in Bangladesh.

The tannery industry produces one of the worst contaminants, and unsafe disposal in nearby waterbodies and landfills has become an imminent threat to public health, especially when the resulting multidrug-resistant bacteria and heavy metals enter community settings and animal food chains. In this study, we have collected 10 tannery wastewater (TWW) samples and 10 additional non-tannery wastewater (NTW) samples to compare the chemical oxygen demand (COD), pH, biological oxygen demand (BOD), dissolved oxygen (DO), total dissolved solids (TDS), chromium concentration, bacterial load, and antibiotic resistance profiles. While COD, pH, and chromium concentration data were previously published from our lab, this part of the study uncovers that TWW samples had a significantly higher bacterial load, compared to the non-tannery wastewater samples (5.89 × 104 and 9.38 × 103 cfu/mL, respectively), higher BOD and TDS values, and significantly lower DO values. The results showed that 53.4, 46.7, 40.0, and 40.0% of the TWW isolates were resistant to ceftriaxone, erythromycin, nalidixic acid, and azithromycin, respectively. On the other hand, 20.0, 30.0, 50.0, and 40.0% of the NTW isolates were resistant to the same antibiotics, respectively. These findings suggest that the TWW isolates were more resistant to antibiotics than the NTW isolates. Moreover, the TWW isolates exhibited higher multidrug resistance than the NTW isolates, 33.33, and 20.00%, respectively. Furthermore, spearman correlation analysis depicts that there is a negative correlation between BOD and bacterial load up to a certain level (r = - 0.7749, p = 0.0085). In addition, there is also a consistent negative correlation between COD and bacterial load (r = - 0.7112, p = 0.0252) and TDS and bacterial load (r = - 0.7621, p = 0.0104). These findings suggest that TWW could pose a significant risk to public health and the environment and highlight the importance of proper wastewater treatment in tannery industries.

Environmental assessment of alkali-activated materials based on agro-industrial waste as alkaline activators through leaching tests.

Global circular economy drives the development of sustainable alkali activated materials (AAM) for use as construction material from industrial by-products and wastes. The assessment of the potentially hazardous substances release of these new material combinations into the soil and groundwater over time is essential. In this study, the aim is the environmental assessment of three AAMs based on blast furnace slag (BFS), activated with almond shell biomass ash (ABA) as potassium source and three solid sources of silica from the agricultural industry, rice husk ash (RHA), spent diatomaceous earth (SDE) and bamboo leaf ash (BLA), using European horizontal leaching tests proposed for construction materials, for monolithic form, Dynamic Surface Leaching Test (DSLT) and for granular form, Up-flow Percolation Test and the Compliance leaching test, by simulating different scenarios of their entire life cycle. The leaching results of the AAM showed the effectiveness of the inertization of all the recycled materials studied, which exceeded some inert materials limits, by means of the activation process. Despite the absence of significant differences in the leaching mechanisms of the oxyanions As, Cr, Mo, Sb, Se and V between the three AAMs developed, they presented different long-term leaching behavior depending on their form, monolithic, or granular, and therefore in their different life cycle stages. Therefore, it is concluded that although the incorporation of agro-industrial waste as alternative activators in BFS based AAM according to the Dutch Soil Quality Decree (for unrestricted use of monolithic and granular materials) is an environmentally acceptable option, the design of waste derived AAMs should be assessed by means of a combination of leaching tests that cover their expected life cycle.

Textile effluent treatment by reductive process using commercial steel wool followed by oxidative process.

Textile industries stand out as one of the main polluters of water resources, generating large amounts of liquid effluents with variable composition and intense coloration. The objective of this work is the integration of the reductive process using commercial steel wool, combined with oxidative processes, in the treatment of textile effluent. The effect of the variables of the reductive process were studied using a 32 factorial design. After 30 minutes, the reductive process allowed a reduction of 68% COD, 46% TOC, 62% true color and 72% of total phenols, but showed an increase in color apparent and turbidity, due to the iron species formed by the oxidation of steel wool during the process. With the combined process using sunlight, the reduction was 73% COD, 50% TOC, 97% phenols, 93% true color and 48% apparent color. With artificial light, the reduction was 94% COD, 63% TOC, 95% phenols, 98% true color and 65% apparent color. The evaluation of the acute toxicity against Daphnia magna indicated that after the proposed treatments, the effluent did not present toxicity or the toxicity was reduced. It is concluded that the combined process can be considered an efficient alternative for the treatment of textile effluent.

Performance evaluation of ICX reactor in treatment of paper mill wastewater: a case study in South Vietnam.

This study evaluates the performance of the Internal Circulation eXperience (ICX) reactor in treating high-strength paper mill wastewater in the south of Vietnam. The ICX reactor effectively managed organic concentrations (sCOD) of up to 11,800 mg/L. Results indicate a volumetric loading rate (VLR) of 26.8 kg/m3 × day, achieving processing efficiency exceeding 81% while consistently maintaining volatile fatty acids (VFA) below 300 mg/L. The study employed Monod and Stover-Kincannon kinetic modeling, revealing dynamic parameters including Ks = 56.81 kg/m3, Y = 0.121 kgVSS/kgsCOD, Kd = 0.0242 1/day, µmax = 0.372 1/day, Umax = 151 kg/m3 × day, and KB = 175.92 kg/m3 × day, underscoring the ICX reactor's superior efficiency compared to alternative technologies. Notably, the reactor's heightened sensitivity to VFA levels necessitates influent concentrations below 1,400 mg/L for effective sludge treatment. Furthermore, the influence of calcium on treatment efficiency requires post-treatment alkalinity maintenance below 19 meq/L to stabilize MLVSS/MLSS concentration. Biogas production ranged from 0.6 to 0.7 Nm3 biogas/kg sCOD; however, calcium impact diminished this ratio, reducing overall treatment efficiency and biogas production. The study contributes valuable insights into anaerobic treatment processes for complex industrial wastewaters, emphasizing the significance of controlling VFA, calcium, and alkalinity for optimal system performance.

Fluoride geochemistry in groundwater at regulated industrial sites.

Few studies apply geochemical concepts governing fluoride fate and transport in natural waters to geochemical conditions at contaminated industrial sites. This has negative implications for designing sampling and compliance monitoring programs and informing remediation decision-making. We compiled geochemical data for 566 groundwater samples from industrial waste streams associated with elevated fluoride and that span a range of geochemical conditions, including alkaline spent potliner, near-neutral pH coal combustion, and acidic gypsum stack impoundments. Like natural systems, elevated fluoride (hundreds to thousands of ppm) exists at the pH extremes and is generally tens of ppm at near-neutral pH conditions. Geochemical models identify pH-dependent fluoride complexation at low pH and carbonate stability at high pH as dominant processes controlling fluoride mobility. Limitations in available thermochemical, kinetic rate, and adsorption/desorption data and lack of complete analyses present uncertainties in quantitative models used to assess fluoride mobility at industrial sites. PRACTITIONER POINTS: Geochemical fundamentals of fluoride fate and transport in groundwater are communicated for environmental practitioners. Fluoride is a reactive constituent in groundwater, and factors that govern attenuation are identified. Geochemical models are useful for identifying fluoride attenuation processes, but quantitative use is limited by thermodynamic data uncertainties.

Exploring industrial lignocellulosic waste: Sources, types, and potential as high-value molecules.

Lignocellulosic biomass has a promising role in a circular bioeconomy and may be used to produce valuable molecules for green chemistry. Lignocellulosic biomass, such as food waste, agricultural waste, wood, paper or cardboard, corresponded to 15.7% of all waste produced in Europe in 2020, and has a high potential as a secondary raw material for industrial processes. This review first presents industrial lignocellulosic waste sources, in terms of their composition, quantities and types of lignocellulosic residues. Secondly, the possible high added-value chemicals obtained from transformation of lignocellulosic waste are detailed, as well as their potential for applications in the food industry, biomedical, energy or chemistry sectors, including as sources of polyphenols, enzymes, bioplastic precursors or biofuels. In a third part, various available transformation treatments, such as physical treatments with ultrasound or heat, chemical treatments with acids or bases, and biological treatments with enzymes or microorganisms, are presented. The last part discusses the perspectives of the use of lignocellulosic waste and the fact that decreasing the cost of transformation is one of the major issues for improving the use of lignocellulosic biomass in a circular economy and green chemistry approach, since it is currently often more expensive than petroleum-based counterparts.

A comparative assessment of treatment methods to release ferulic and p-cumaric acids from Brewer's Spent Grains.

Brewers' spent grain (BSG) is the main byproduct from the brewing industry, which accounts for 85 % of the total waste generated during beer production. This lignocellulosic material is traditionally used as livestock feed and sold at a low price. However, BSG can be used as a low-cost feedstock for the production of bioactive molecules and chemicals precursors, upgrading the value of this byproduct. In this context, BSG is a promising feedstock for the extraction of antioxidants like ferulic acid (FA) and p-coumaric acid (p-Cu). The effectiveness of three hydrolysis treatments were evaluated for the extraction of FA and p-Cu from BSG, namely enzymatic (based on the synergistic cooperation between a feruloyl esterase and an endo-1,4-ß-xylanase), alkaline and hydrothermal. The hydrothermal treatment produced the highest extraction yields (7.2 g/kgBSG and 1.4 g/kgBSG for FA and p-Cu, respectively) in a short extraction time (an hour). On the other hand, enzymatic hydrolysis extracted 4.3 g/kgBSG for FA and negligible yields for p-Cu in 4 h of incubation at 25 °C. Yields of 5.5 g/kgBSG for FA and 0.6 g/kgBSG for p-Cu were obtained in more than 5 h of alkaline treatment at 120 °C. The mass and energy balances revealed the high dependence of the operating costs on the concentration of BSG used during the extraction process, with costs of 34.5 €, 6607 € and 205.5 € per kg of FA for the chemical, enzymatic and hydrothermal extraction methods at 100 kg BSG/m3.

Bioactivity of selenium nanoparticles biosynthesized by crude phycocyanin extract of Leptolyngbya sp. SSI24 cultivated on recycled filter cake wastes from sugar-industry.

BACKGROUND: Beet filter cake (BFC) is a food-grade solid waste produced by the sugar industry, constituting a permanent source of pollution. Cyanobacteria are considered a sustainable resource for various bioactive compounds such as phycocyanin pigment with valuable applications. This study aimed to use beet filter cake extract (BFCE) as an alternative medium for the economic cultivation of cyanobacterium Leptolyngbya sp. SSI24 PP723083, then biorefined the bioactive component such as phycocyanin pigment that could be used in the production of selenium nanoparticles. RESULTS: The results of the batch experiment displayed that the highest protein content was in BG11medium (47.9%); however, the maximum carbohydrate and lipid content were in 25% BFCE (15.25 and 10.23%, respectively). In addition, 75% BFCE medium stimulated the phycocyanin content (25.29 mg/g) with an insignificant variation compared to BG11 (22.8 mg/g). Moreover, crude phycocyanin extract from Leptolyngbya sp SSI24 cultivated on BG11 and 75% BFCE successfully produced spherical-shaped selenium nanoparticles (Se-NPs) with mean sizes of 95 and 96 nm in both extracts, respectively. Moreover, XRD results demonstrated that the biosynthesized Se-NPs have a crystalline nature. In addition, the Zeta potential of the biosynthesized Se-NPs equals - 17 mV and - 15.03 mV in the control and 75% BFCE treatment, respectively, indicating their stability. The biosynthesized Se-NPs exhibited higher effectiveness against Gram-positive bacteria than Gram-negative bacteria. Moreover, the biosynthesized Se-NPs from BG11 had higher antioxidant activity with IC50 of 60 ± 0.7 compared to 75% BFCE medium. Further, Se-NPs biosynthesized from phycocyanin extracted from Leptolyngbya sp cultivated on 75% BFCE exhibited strong anticancer activity with IC50 of 17.31 ± 0.63 µg/ml against the human breast cancer cell line. CONCLUSIONS: The BFCE-supplemented medium can be used for the cultivation of cyanobacterial strain for the phycocyanin accumulation that is used for the green synthesis of selenium nanoparticles that have biological applications.

Isolation and characterization of mercury and multidrug-resistant Citrobacter freundii strains from tannery effluents in Kolkata, India.

Mercury (Hg) is one of the most potent toxic heavy metals that distresses livestock, humans, and ecological health. Owing to uncontrolled exposure to untreated tannery industrial effluents, metals such as Hg are increasing in nature and are, therefore, becoming a global concern. As a result, understanding the thriving microflora in that severe condition and their characteristics becomes immensely important. During the course of this study, two Hg-resistant bacteria were isolated from tannery wastewater effluents from leather factories in Kolkata, India, which were able to tolerate 2.211 × 10- 3 M (600 µg/ml) Hg. 16 S rDNA analysis revealed strong sequence homology with Citrobacter freundii, were named as BNC22A and BNC22C for this study. In addition they showed high tolerance to nickel (Ni) and Chromium (Cr) at 6.31 × 10- 3 M (1500 µg/ml) and 6.792 × 10- 3 M (2000 µg/ml) respectively. However, both the isolates were sensitive to arsenic (As) and cadmium (Cd). Furthermore, their antibiotic sensitivity profiles reveal a concerning trend towards resistance to multiple drugs. Overuse and misuse of antibiotics in healthcare systems and agriculture has been identified as two of the main reasons for the decline in efficacy of antibiotics. Though their ability to produce lipase makes them industrially potent organisms, their competence to resist several antibiotics and metals that are toxic makes this study immensely relevant. In addition, their ability to negate heavy metal toxicity makes them potential candidates for bioremediation. Finally, the green mung bean seed germination test showed a significant favourable effect of BNC22A and BNC22C against Hg-stimulated toxicity.

Ladle slag-based binder for the solidification/stabilization of heavy-metal-rich industrial waste.

Heavy metal pollution from industrial sources is a major environmental and health hazard on a global scale. This study introduces a solidification/stabilization method of industrial waste using a waste-based, ettringite-rich solid binder from ladle slag and gypsum for the immobilization of an industrial waste material with extremely high contents of several heavy metals. The importance of sulfate and water content on the immobilization efficiency and the use of citric acid to increase the processing time of the binder were studied. The leaching of Pb, Hg, Se, As, Cd, Cu, and Ni was measured, and X-ray powder diffraction, field-emission scanning electron microscopy, and field-emission electron probe microanalysis combined with wavelength-dispersive X-ray spectroscopy were used to analyze the structure of the hardened binder and the location of the heavy metals within. The study shows that the ladle slag/gypsum binder is suitable for the solidification/stabilization of heavy-metal-rich solid industrial waste. Hg, As, Cd, Cu, and Ni were fully immobilized in all scenarios covered in the study, whereas Pb and Se showed more complicated behaviors. The main immobilization method was encapsulation, and partial Se incorporation into ettringite was observed. The presence of citric acid increased the processing time of the binder without harming the immobilization, unless combined with low sulfate content.

Evaluation of kikuyu grass wetland for wastewater treatment efficiency from malt factory, Ethiopia.

BACKGROUND: The majority of existing industries in Ethiopia discharge untreated effluents into nearby water bodies, streams and open land. The wastewater generated by Gondar malt factory (GMF) was disposed freely and join a natural wetland implemented for the treatment of the wastewater. The objective of the study was to analyze and characterize wastewater from GMF and to evaluate the effectiveness of the wetland for the treatment purpose. METHODS: Different Physicochemical quality indicators (color, turbidity pH, temperature, Total Dissolved solids, Total Suspended solids, total solid, conductivity, alkalinity, hardness, nitrate, phosphate, sulfate, free chlorides, heavy metals-(Cd, Cr, Fe, Mn, and Pb)and Biological Oxygen Demand were measured according to the standard procedures. Data was analyzed using Statistical Package for Social Sciences (SPSS-25). Analysis of Variance (ANOVA) was used to find whether significant differences existed in the different sampling stations for the parameters studied. P value less than 0.05 was considered to show significant difference. RESULTS: The results of this study revealed that most of the quality indicators were improved in value after the water passed through the wetland except for alkalinity M, sulfite, Mn, temperature and pH. From ANOVA result, it was noted that there was a significant mean difference between the stations except for chromium, manganese and lead. The result showed that the wetland plays a great role in the removal of pollutants where the best performance was obtained at removal efficiency of 96.188% PO4HR,75.63% Nitrate,>99% Cl2, ammonia and nitrite 99.99%, 92.77% sulfate,84.36% Total hardness,87.43% color, and for others it is ranged between 30 and 60%. CONCLUSION: the study concluded that GMF wetland was almost effective and had potential in treatment of the wastewater from the discharging facilities (especially for nutrients, alkalinity P, hardness, color and chloride). It is recommended that wetlands should be conserved and used as wastewater treatment facility.

The significant impact of MPs in the industrial/municipal effluents on the MPs abundance in the Nakdong River, South Korea.

Owing to extensive plastic consumption, wastewater from households, business establishments, and industrial activities have been recognised as a significant contributor to microplastics (MPs) in aquatic environments. This case study represents the first investigation of MPs in the Nakdong River, Republic of Korea, that traverses through the largest industrial complex midstream and densely populated cities of Daegu and Busan downstream before flowing into the sea. Monitoring of MP abundance in effluents discharged from three municipal, two industrial, and one livestock wastewater treatment plant (WWTP) into the Nakdong River was conducted over four seasons from August 2022 to April 2023. Identification and quantification of MPs were performed using micro-Fourier transform infrared spectrometry. Seasonal variation in MPs in the Nakdong River was found to be strongly influenced by the nearest upstream WWTPs and rivers, exhibiting a linear relationship that decreased gradually with increasing distance from the WWTPs. The average concentrations of MPs in the six effluent sources ranged from 101 ± 13 to 490 ± 240 particles/L during the yearly monitoring period, while MP concentrations in the river ranged between 79 ± 25 and 120 ± 43 particles/L. Industrial effluents contained higher amounts of discharged MPs (314 ± 78 particles/L) than municipal sources (201 ± 61 particles/L). Notably, two municipal WWTPs, located in the highly densely populated city, discharged the highest total MP amounts per day and released the greatest volumes of effluents. This study provides valuable insights into the monitoring and impact of effluents on MPs in rivers, which could inform MP treatment and management strategies for in river and marine environments.

Efficiency enhancement of electrocoagulation, ion-exchange resin and reverse osmosis (RO) membrane filtration by prior organic precipitation for treatment of anaerobically-treated palm oil mill effluent.

Anaerobically-treated palm oil mill effluent (POME) still has unacceptable properties for water recycling and reuse, with an unpleasant appearance due to the brownish color caused by tannins and phenolic compounds. This study proposes an approach for treating anaerobically-treated POME for water recycling by combining organic precipitation, electrocoagulation (EC), and ion-exchange resin, followed by reverse osmosis (RO) membrane filtration in series. The results indicated that the organic precipitation enhanced the efficiency of EC treatment in reducing the concentrations of tannins, color, and chemical oxygen demand (COD) of the anaerobically-treated POME effluent, with reductions of 95.73%, 96.31%, and 93.96% for tannin, color, and COD, respectively. Moreover, organic precipitation affected the effectiveness of Ca2+ and Mg2+ ion removal using ion exchange resin and RO membrane filtration. Without prior organic precipitation, the ion-exchange resin process required a longer contact time, and the RO membrane filtration treatment was hardly effective in removing total dissolved solids (TDS). The combined process gave a water quality that meets the criteria set by the Thailand Ministry of Industry for industrial boiler use (COD 88 mg/L, TDS <0.001 mg/L, water hardness <5 mg-CaCO3/L, and pH 6.9).

Application of soil magnetometry and geochemical methods to investigate soil contamination with antimony.

The aim of the study was an assessment of the pollution level and identification of the antimony sources in soils in areas subjected to industrial anthropopressure from: transport, metallurgy and electrical waste recycling. The combination of soil magnetometry, chemical analyzes using atomic spectrometry (ICP-OES and ICP-MS), Sb fractionation analysis, statistical analysis (Pearson's correlation matrix, factor analysis) as well as Geoaccumulation Index, Pollution Load Index, and Sb/As factor allowed not only the assessment of soil contamination degree, but also comprehensive identification of different Sb sources. The results indicate that the soil in the vicinity of the studied objects was characterized by high values of magnetic susceptibility and thus, high contents of potentially toxic elements. The most polluted area was in the vicinity of electrical waste processing plants. Research has shown that the impact of road traffic and wearing off brake blocks, i.e. traffic anthropopression in general, has little effect on the surrounding soil in terms of antimony content. Large amounts of Pb, Zn, As and Cd were found in the soil collected in the vicinity of the heap after the processing of zinc-lead ores, the average antimony (11.31 mg kg-1) content was lower in the vicinity of the heap than in the area around the electrical and electronic waste processing plant, but still very high. Antimony in the studied soils was demobilized and associated mainly with the residual fraction.

Improved recycling of a gasification fly ash: An integrated waste management approach within the framework of a Circular Economy.

A Circular Waste Management alternative is considered in this paper in which a complete ash valorization process is proposed for an Integrated Gasification with Combined Cycle fly ash, trying to extract maximum value from this waste before it is discarded. In the paper, germanium, a scarce resource vital in our modern society, is first extracted from fly ash using water, with an extraction yield of 85%, and subsequently, the leached fly ash is used in the manufacture of fire-resistant boards containing 60% ash, thereby avoiding its disposal in a landfill. The potential environmental impact caused by the two stages of the process was analyzed, and the final effluent was considered to achieve a zero-discharge objective. This paper contributes to the development of a more sustainable management alternative for an industrial waste produced in increased amounts and provides the basis for a symbiotic coupling relationship among various industrial sectors.

Co-flotation of effluents from detergent and marble processing industries in Denver and dispersed air flotation systems.

Suspended solids in the marble processing wastewater (MPWW) have the potential to pollute receiving media. Likewise, detergent production wastewater (DPWW) needs treatment prior to discharge as they include surfactants and others. Flotation and its modifications are common for separation purposes in various engineering solutions. To increase flotation performance by changing the surface tension some collector and frother chemicals, surfactants are utilized. Detergents are among important surfactants and they may act as both frother and collector in flotation. Therefore, the purpose of this study was to determine the effectiveness of DPWW in co-flotation with MPWW. Two effluents were mixed at varying ratios and dispersed air (DISP) and Denver (DEN) flotation co-treatment were applied to the mixtures. Volume ratio, time and air flow rate on treatment performance were investigated. Turbidity, solids, COD, phosphate removals were achieved at varying levels when the flotation was applied to the mixture. The highest treatment performance was achieved at 90%MPWW-10%DPWW mixture. 10 min flotation time and 2 L min-1 air flow rate for the DEN system, and 20 min and 6 L min-1 for the DISP system were recommended. Under these conditions turbidity, SS, COD, phosphate and alkalinity residuals (and removal efficiencies) were 2400 NTU(82%), 1720 mg.L-1(89%), 313.6 mg.L-1(10%), 20 mg.L-1(20%) and 600 mg.L-1CaCO3(92%) in the DEN system, respectively. Whereas, in the DISP system, under the same conditions, final values of 1880 NTU(86%), 1540 mg.L-1(91%), 262 mg.L-1(17%), 21 mg.L-1(20%) and 470 mg.L-1(94%) were obtained, respectively. The highest SludgeSS concentration increased up to 19300 mg.L-1 in the 90%-10% mixture. In all samples, dewaterable sludge was obtained. By this study, co-flotation of these two effluents was recommended. Within SDGs, this approach will replace frother chemical usage. The process performance can further be enhanced via flotation modifications and technology can be developed as further study.

Low-cost optimization of industrial textile landfill sludge re-dewatering using ferrous sulfate and blast furnace slag.

This study was based on an industrial sludge landfill with a scale of 1 million cubic meters, which had been filled for more than 10 years. It focused on the secondary dewatering of industrial textile landfill sludge (LS) with a total organic carbon (TOC) content greater than 50% and a volatile suspended solids to suspended solids (VSS/SS) ratio of 0.59. A response surface methodology (RSM) model was established using the coagulant ferrous sulfate (FeSO4) and conditioning agents such as hydrated magnesium oxide (MgO), blast furnace slag (BFS), and calcium oxide (CaO). By solving the RSM equations for the respective indicators, the optimal dosages of FeSO4, MgO, and BFS were determined to be 90 mg/g of dry sludge (DS), and for CaO 174.85 mg/g DS. Further examinations of the dewatering performance, apparent properties, extracellular polymeric substances (EPS) components, rheological characteristics, moisture distribution, and pollutant content variation led to the development of a green waste-based dewatering agent composed of FeSO4 and BFS. In small-scale diaphragm plate and frame filter press tests, the optimal water content (WC) was 69.11%. In the final production-scale experiments, it was 65.72%, with the actual application cost being only 13.07 $/ton DS. Additionally, when FeSO4 and BFS were used together, the combined action of Fe and Si could significantly reduce the biotoxicity of heavy metals (HMs), cut down 75.2% of the LS's TOC, and effectively reduced the leaching of organic substances from the leachate, which was beneficial for subsequent disposal. In conclusion, the combined use of FeSO4 and BFS for the secondary dewatering of industrial textile LS was economically efficient, effective in dewatering, and had significant harm reduction effects, making it a worthwhile for waste treatment.

Lignin nanoparticles from Ayurvedic industry spent materials: Applications in Pickering emulsions for curcumin and vitamin D3 encapsulation.

Lignin nanoparticles (LNP), extracted from spent materials of Dashamoola Arishta (Ayurvedic formulation), shared a molecular weight of 14.42 kDa with commercial lignin. Processed into LNPs (496.43 ± 0.54 nm) via planetary ball milling, they demonstrated stability at pH 8.0 with a zeta potential of -32 ± 0.27 mV. Operating as Pickering particles, LNP encapsulated curcumin and vitamin D3 in sunflower oil, forming LnE + Cu + vD3 nanoemulsions (particle size: 347.40 ± 0.71 nm, zeta potential: -42.27 ± 0.72 mV) with high encapsulation efficiencies (curcumin: 87.95 ± 0.21%, vitamin D3: 72.66 ± 0.11%). The LnE + Cu + vD3 emulsion exhibited stability without phase separation over 90 days at room (27 ± 2 °C) and refrigeration (4 ± 1 °C) temperatures. Remarkably, LnE + Cu + vD3 exhibited reduced toxicity, causing 29.32% and 34.99% cell death in L6 and RAW264.7 cells respectively, at the highest concentration (50 µg/mL). This underscores the potential valorization of Ayurvedic industry spent materials for diverse industrial applications.