Effective Detoxification of Olive Mill Wastewater Using Multi-Step Surfactant-Based Treatment: Assessment of Environmental and Health Impact.

Olive mill wastewater (OMW) poses a significant environmental challenge and health concern in olive-producing countries, including Jordan. Surfactant micelles are frequently employed as solubilizing agents to enhance the water solubility of chemical compounds. This study aims to leverage the sodium dodecyl sulfate (SDS) micelles in a multi-step process to detoxify OMW for agricultural and industrial uses and reduce its impact. The OMW was treated in multiple steps: screening, coagulation with different chemicals, and distillation with different surfactants. The treatment steps were monitored using LC-MS, GC-MS, ICP-MS, chemical oxygen demand contents, and total phenolic compounds. The detoxification of OMW was evaluated using standard germination assays, MTT assays using tissue culture, and toxicity assays using fluorescence bacteria. Following the treatment, the seed growth rate improved significantly from 0% to 100%. The GC-MS revealed a substantial decrease in pollutants. The concentration of polyphenols was reduced to 2.5%, while the COD level decreased to 35%. The toxicity in bacteria was significantly reduced in a time-dependent manner, and the toxicity in human cells decreased by 95%. Additionally, between 50% and 95% of metals in OMW were removed. The multi-step SDS-based approach successfully detoxified the OMW and enhanced water quality, which would pave the road for its direct application in industry and agriculture.

Impacts of industrial food wastes on nutritional value of mealworm (Tenebrio molitor) and its gut microbiota community shift.

The extensive investigation into the capacity of mealworms to digest diverse food by-products, as well as plastic wastes, has been a focal point in recent years. The transition from traditional diet sources like brans to food wastes has the potential to impact the physiological properties of mealworms. This study explored the utilization of various industrial food wastes such as okara, barley spent grain (BSG), sesame oil meal (SOM), and spent coffee grounds (SCG) as feed alternatives, and reports on their survival rate, biomass variations, and nutritional composition. In additional, the shift in their gut microbiota was also assessed. Among the range of industrial food wastes, mealworms exhibited the most robust growth performance when nourished with BSG. This particular group showed a survival rate of 98.33 % and a biomass increase of 23.06 %. In contrast, mealworms fed with SCG demonstrated the lowest survival rate and experienced a significant reduction in biomass. Although the groups fed with okara and SCG displayed moderate growth performance, both exhibited protein levels comparable to those observed in the oatmeal-fed group (used as the positive control). Notably, the inclusion of BSG in the mealworm diet exhibited the potential to enrich their omega-3 fatty acid content, suggesting potential benefits for applications as animal feed or even human consumption. Furthermore, an analysis of the gut microbiome was conducted to investigate the associations between specific diets and the composition of mealworm gut microbiota. In summary, food wastes such as BSG may be repurposed as feed substrates for mealworms before converting them into an alternative source of protein.

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.

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.

LCA analysis for assessing environmenstal sustainability of new biobased chemicals by valorising citrus waste.

The global shift towards using biomass for biofuels and chemicals is accelerating due to increasing environmental concerns and geopolitical strategies. This study investigates a biorefinery model using citrus-processing-waste, specifically citrus pulp, to produce high-value products for various industries, including cosmetics, pharmaceuticals, flavours, fragrances, and food packaging. In Italy, particularly Sicily region, citrus processing generates significant amounts of waste, often improperly disposed of, contributing to environmental problems. Researchers have demonstrated that citrus waste can yield commercially valuable compounds. This study specifically focuses on orange peel waste (OPW), which constitutes about half of the fruit's weight, aiming to extract pectin and limonene through a combined process. The extraction process was carried out on a laboratory scale, and its sustainability was evaluated using a life cycle assessment (LCA) with SimaPro 8.1 software and the Impact 2002 + method. The functional unit adopted for this study is 300 g of OPW, obtained after the pre-treatment phase, from which 0.14 g of limonene and 8.22 g of pectin were extracted. The LCA results revealed that pectin extraction has a significantly higher environmental impact compared to limonene extraction, primarily due to the use of ethanol as a solvent, followed by electricity consumption. To mitigate this impact, the LCA assessed alternative, more sustainable solvents, resulting in a 73.4% reduction in the environmental footprint of the pectin extraction process. These findings underscore the critical role of LCA, even at the laboratory scale, in identifying environmental hotspots and providing insights for improving and optimizing processes for potential industrial-scale applications.

From Waste to Health: Olive Mill Wastewater for Cardiovascular Disease Prevention.

Waste from the agri-food chain represents a valuable reservoir of organic compounds with health-promoting properties. Momast Plus 30 Bio (MP30B) is a derivative obtained from olive-oil wastewater. Its enrichment in hydroxytyrosol (HT) via a patented technique has paved the way for its potential application as a dietary supplement in preventing cardiovascular diseases. MP30B demonstrates no significant alteration in cardiac and vascular parameters in "ex vivo" studies. However, it exhibits a strong ability to remove reactive oxygen species and exerts anti-inflammatory effects, notably reducing the concentration of iNOS and mitigating heart infections in "in vitro" experiments. Furthermore, MP30B slightly decreases the stiffness of the "ex vivo" thoracic aorta, potentially resulting in lowered arterial pressure and enhanced energy transfer to a normal ventricle. Based on these findings, we posit MP30B as a promising extract for cardiovascular disease prevention, and its specific antibacterial properties suggest its utility in preventing cardiac infections.

Assessment and monitoring of leather effluent discharge from Dewas and Ranipet and their computational approach.

The swift pace of industrialization, urbanization, and burgeoning populations propel the surge in demand for manufactured goods and infrastructure. The wastewater produced during leather processing comprises a cocktail of organic and inorganic chemical contaminants that have the potential to affect the environment. This study focuses on conducting a comparative physico-chemical, analytical, in vitro, and in silico toxicity assessment and monitoring of leather effluent discharged from two different areas, namely, Dewas and Ranipet. The physicochemical analysis of collected effluents revealed higher levels of biochemical oxygen demand, chemical oxygen demand, total dissolved solids, total suspended solids, and heavy metals than the permissible limit fixed by the Central Pollution Control Board (CPCB). The X-ray powder diffraction analysis of both samples identified the existence of crystalline and amorphous phases. The functional composition of compounds was identified through the analysis of Fourier-Transform Infrared Spectroscopy, which revealed the existence of C-H, O-H, N-H, C = O, C=C, and C≡C stretching vibrations. A variety of compound derivatives, including amines, organic acids, organometallic compounds, alcohols, hydrocarbons, esters, aldehydes, ketones, aromatic, and organogermanium, were identified by Gas Chromatography-Mass Spectrometry. An assessment and monitoring of the phytotoxicity of effluent on the germination of Vigna radiata seeds reveals that (100%) of both Dewas and Ranipet leather effluents inhibited seed germination by 33.34% and 100%. The incorporation of Absorption-Distribution-Metabolism-Excretion-Toxicity (ADMET) analysis improved comprehension of the toxicity profiles of the GC-MS-identified compounds. Moreover, the result of docking studies revealed that cytochrome P450 showed the highest binding affinity towards 1,3-benzodioxol-2-one, hexahydro-cis with an affinity score of - 7.1 kcal/mol. The overall research revealed that the leather effluents from Dewas and Ranipet exhibit significant toxicity, highlighting the necessity of better wastewater management. In the future, innovative treatment methods and environmental friendly processes can be developed to minimize the detrimental effects of leather effluents.

Benzotriazoles and bisphenols in wastewater from the food processing industry and the quantitative changes during mechanical/biochemical treatment processes.

Benzotriazoles (BTRs) and bisphenols (BPs), categorized as contaminants of emerging concern (CECs), pose significant risks to human health and ecosystems due to their endocrine-disrupting properties and environmental persistence. This study investigates the occurrence and behavior of nine BTRs and ten BPs in wastewater generated in a large-scale meat processing plant, evaluating the effectiveness of a modern mechanical-biological industrial on-site treatment plant in removing these contaminants, and based on the concentration levels from eleven sampling points at different stages of the treatment process. The method used to determine these micropollutants' concentration was ultrasound-assisted emulsification-microextraction for analytes isolation and gas chromatography-mass spectrometry for detection (USAEME-GC/MS). The results indicate that the rigorous quality control processes in the meat processing facility effectively limit the presence of these micropollutants, especially concerning BPs, which are absent or below detection limits in raw wastewater. While the concentrations of some of these micropollutants increased at different points in the treatment process, these values were relatively low, typically below one microgram per liter. Among the compounds analyzed, the only one present after completing the treatment was 5Cl-BTR (maximum concentration: 3007 ng/L), and these contamination levels are around seven times lower than the reference value associated with non-cancer health risk for drinking water. This study contributes to understanding these CECs in industrial wastewater and highlights the importance of effective treatment systems for environmental protection.

Linking industrial emissions and dietary exposure to human burdens of polychlorinated naphthalenes.

Relationships between toxic pollutant emissions during industrial processes and toxic pollutant dietary intakes and adverse health burdens have not yet been quantitatively clarified. Polychlorinated naphthalenes (PCNs) are typical industrial pollutants that are carcinogenic and of increasing concern. In this study, we established an interpretable machine learning model for quantifying the contributions of industrial emissions and dietary intakes of PCNs to health effects. We used the SHapley Additive exPlanations model to achieve individualized interpretability, enabling us to evaluate the specific contributions of individual feature values towards PCNs concentration levels. A strong relationship between PCN dietary intake and body burden was found using a robust large-scale PCN diet survey database for China containing the results of the analyses of 17,280 dietary samples and 4480 breast milk samples. Industrial emissions and dietary intake contributed 12 % and 52 %, respectively, of the PCN burden in breast milk. The model quantified the contributions of food consumption and industrial emissions to PCN exposure, which will be useful for performing accurate health risk assessments and developing reduction strategies of PCNs.

Ecotoxicological assessment of waste foundry sands and the application of different classification systems.

The application of a battery of bioassays is widely recognized as a useful tool for assessing environmental hazard samples. However, the integration of different toxicity data is a key aspect of this assessment and remains a challenge. The evaluation of industrial waste leachates did not initially undergo any of the proposed integration procedures. This research addressed this knowledge gap. Twenty-five samples of waste foundry sands were subjected to a leaching test (UNI EN 12457-2) to evaluate waste recovery and landfill disposal. The leachates were evaluated using a battery of standardized toxicity bioassays composed of Aliivibrio fischeri (EN ISO 11348-3), Daphnia magna (UNI EN ISO 6341), and Pseudokirchneriella subcapitata (UNI EN ISO 8692), both undiluted and diluted. Daphnia magna and P. subcapitata were the most affected organisms, with significant effects caused by 68% and 64% of undiluted samples, respectively. The dilution of samples facilitates the calculation of EC50 values, which ranged from greater than the highest concentration tested to 2.5 g/L for P. subcapitata. The data on single-organism toxicity were integrated using three methods: the Toxicity Classification System, the toxicity test battery integrated index, and the EcoScore system. The three classifications were strongly similar. According to all applied systems, three samples were clearly nontoxic (from iron casting plants) and two were highly toxic (from steel casting plants). Moreover, the similar ranking between undiluted and diluted leachates suggests the possibility of using only undiluted leachates for a more cost-effective and time-efficient screening of waste materials. The findings of this study highlight the usefulness of integrating ecotoxicological waste assessment. Integr Environ Assess Manag 2024;20:2294-2311. © 2024 The Author(s). Integrated Environmental Assessment and Management published by Wiley Periodicals LLC on behalf of Society of Environmental Toxicology & Chemistry (SETAC).

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.

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.

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.

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.

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.

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.

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.

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.