Industrial Wastewater Streams Research Articles

Synergistic role of indium doping and g-C3N4 reinforcement in boosting the visible light-triggered rhodamine B and diclofenac sodium salt degradation over rare earth molybdate

Designing and fabricating cost-efficient and eco-friendly photocatalysts for removing organic pollutants from wastewater streams is a crucial research objective for effectively managing industrial effluents to tackle environmental sustainability issues. In this study, we prepared bare cerium molybdate (Ce2(MoO4)3, M1) and indium-doped cerium molybdate (In- Ce2(MoO4)3, M2) photocatalysts via a hydrothermal method. We then synthesized a nanocomposite of In- Ce2(MoO4)3 (M3) with the promising material graphitic carbon nitride (g-C3N4) using an ultrasonication approach. The synthesized photocatalysts were effectively applied to degrade the Rhodamine B dye and diclofenac sodium salt (a drug) from synthetic industrial wastewater through a photocatalysis approach. The impact of indium (In3+) doping on the bare (Ce2(MoO4)3 and the strong interaction between the (In-Ce2(MoO4)3 and g-C3N4 nanosheets were analyzed through physical and electrochemical techniques, including SEM, EDS, XRD, FTIR, UV–Vis spectroscopy, and EIS analysis. The comprehensive photocatalytic degradation of dye and the drug via first-order kinetic parameters under visible light irradiation for all the prepared catalyst samples was evaluated. The nanocomposite In-Ce2(MoO4)3/g-C3N4 exhibited excellent photocatalytic activity, degrading the maximum amount of RhB dye and drug (RhB:96 %, drug:87 %) in 90 min with a higher rate constant (k) compared to In-Ce2(MoO4)3 (RhB:69 %, drug:56 %) and Ce2(MoO4)3 (RhB:56 %, drug:38 %). Furthermore, the In-Ce2(MoO4)3/g-C3N4 samples produced a 7-fold and 3-fold increase in transient photogenerated current response compared to pristine Ce2(MoO4)3 and In-Ce2(MoO4)3 samples, respectively. These findings pave the way for synthesizing an economical, versatile, and efficient In-Ce2(MoO4)3/g-C3N4 photocatalyst to eliminate pollutants from industrial wastewater streams and boost environmental sustainability.

Phytogenic aqueous extract mediated fabrication of Ag-Fe2O3 nanohybrids for detoxification of carcinogenic Congo Red dye: An Environmental Remediation approach

<p>In current study environment benign silver-iron oxide (Ag-Fe2O3) nanohybrid structures are fabricated as catalyst for CR dye decolorization. Industrial wastewater stream possesses several toxic dyes which are toxic carcinogen pollutants cause severe environmental disorders. Detoxification of Congo Red dye is carried out by silver-iron oxide nanohybrid structures having latent catalytic efficiency for dye decolorization. Silver iron oxide nanohybrid materials are fabricated from AgNO3, FeSO4/ FeCl3 and Citrus limon aqueous extract by doping AgNPs on Fe2O3 materials. For characterization of Ag-Fe2O3 nanostructures, UV-Visible, X-ray diffraction (XRD), Scanning electron microscope (SEM) and Fourier transform infrared (FT-IR) techniques are used. The crystallite size is measured from Debye Scherer equation and average size calculated is 54.3 nm. Furthermore, UV-Visible spectrophotometer is used to study the catalytic efficiency of Ag-Fe2O3 nanohybrid material which is observed to be >80% within 10 minutes. Moreover, parameters like contact time, dosage of catalyst, temperature and pH are measured to optimize reaction conditions for the dye degradation by adding prepared nanohybrids. The kinetic studies were performed for the degradation reaction and were originate to follow first order kinetics. Reusability test is also applied to check the stability of nanohybrid catalyst that affirmed it to be as highly stable nanomaterial.</p>

A comparative analysis of organic substrates from industrial wastewater streams for enhanced electricity production using a double chamber microbial fuel cell (DCMFC)

This study investigates the startup sequence of a Double Chamber Microbial Fuel Cell (DCMFC) for the treatment of diverse industrial wastewater streams, including biorefinery, dairy, and mixed sources. It presents a comprehensive startup and calibration procedure for the essential electrical components, utilizing MATLAB-SIMULINK to establish typical resistance calibration curves and correlate measured electrical parameters with expected values. This approach enables a robust experimental startup protocol for the DCMFC under psychrophilic and thermophilic conditions. The study explores the impact of fundamental operating parameters on determining the experimental Hydraulic Retention Time (HRT) of the DCMFC. Specifically, it examines the effects of catholyte type (Phosphate PO43−buffer) and three distinct organic substrates: dairy wastewater, biorefinery wastewater, and mixed substrates (50% v/v dairy).Electricity production is evaluated in terms of voltage yield (mV), Columbic efficiency (CE) (%), and overall growth yield (Y). The study also assesses the COD (Chemical Oxygen Demand) mass balance component's influence on COD removal efficiency to establish a viable operating HRT during the startup phase. Key findings include startup experimental voltage yields of 145.2 mV for biorefinery, 85 mV for mixed wastewater, and an impressive 357 mV for dairy wastewater. Columbic efficiencies of 0.92%, 0.77%, and 0.02% were respectively achieved. Furthermore, the study reveals a viable experimental HRT, ranging from 72 to 96 hours, for both biorefinery/mixed and dairy/mixed wastewater sources, facilitating startup electricity generation and efficient removal of organic contaminants. These findings contribute to the advancement of sustainable wastewater treatment and bioelectricity generation, offering valuable insights for practical applications.

Heavy metals accumulation by Vicia faba L and Pisum sativum L plants grown in contaminated soil

This study was conducted in agricultural fields near the city of Al-Marj. Al- Marj area is located on the southern coast of the Mediterranean Sea in the province of Cyrenaica . Many vegetables and fruits grow in these agricultural fields, and the domestic and industrial wastewater streams pass through them, and the study aimed to determine the quantity of heavy metals( Cd ,Ni, and Pb) in leguminous plants beans( Vicia faba L) and peas (Pisum sativum L) growing in soil contaminated with domestic and industrial wastewater. All the experiments were conducted at the Al-Bariqa company laboratory in Tripoli, Libya. Samples of some grown vegetables, i.e.,beans( Vicia faba L ) and peas (Pisum sativum L),were collected from seven different locations in the agricultural fields. For metal analysis, only the pods of in two studied plants samples were used, Three replicates were taken from plant samples. The study results showed that pods of studied plants in different locations contained heavy metals with different concentrations within the normal levels of toxicity except cadmium .the concentration of cadmium was over then (0.1)ppm., which was applied by (WHO)

Beyond Microplastics: Implementation of a Two-Stage Removal Process for Microplastics and Chemical Oxygen Demand in Industrial Wastewater Streams

Wastewater from plastic manufacturing or processing industries is often highly polluted with microplastics (MPs) and high levels of oxidizable organic matter, which results in a high chemical oxygen demand (COD). When industrial wastewater enters wastewater streams, the high microplastic load is a high burden for municipal wastewater treatment plants (WWTPs), as they are not sufficiently removed. To prevent MP from entering the WWTPs, an upstream prevention method is essential. This paper presents a pilot-scale plant study for the removal of MP and COD from industrial wastewater that was tested on-site at a plastic manufacturer in Germany. Eight test phases were performed over 3 months, with each test phase processing 1 m3 wastewater and four treatments. Per test phase, 12 samples were analyzed for 5 parameters: COD, total suspended solids (TSSs), particle count, pH, and turbidity. The results showed an average decrease in MP by 98.26 ± 2.15% measured by TSSs and 97.92 ± 2.31% measured by particle count. This prevents the emission of 1.1 kg MP/m3 water and an estimated 2.7 t MP/year. The COD was reduced efficiently by 94.3 ± 8.9%. Besides MP and COD, this treatment allows reuse of water and agglomerates, resulting in a reduction in the CO2 footprint.

Stripped: contribution of cyanobacterial extracellular polymeric substances to the adsorption of rare earth elements from aqueous solutions.

The transformation of modern industries towards enhanced sustainability is facilitated by green technologies that rely extensively on rare earth elements (REEs) such as cerium (Ce), neodymium (Nd), terbium (Tb), and lanthanum (La). The occurrence of productive mining sites, e.g., is limited, and production is often costly and environmentally harmful. As a consequence of increased utilization, REEs enter our ecosystem as industrial process water or wastewater and become highly diluted. Once diluted, they can hardly be recovered by conventional techniques, but using cyanobacterial biomass in a biosorption-based process is a promising eco-friendly approach. Cyanobacteria can produce extracellular polymeric substances (EPS) that show high affinity to metal cations. However, the adsorption of REEs by EPS has not been part of extensive research. Thus, we evaluated the role of EPS in the biosorption of Ce, Nd, Tb, and La for three terrestrial, heterocystous cyanobacterial strains. We cultivated them under N-limited and non-limited conditions and extracted their EPS for compositional analyses. Subsequently, we investigated the metal uptake of a) the extracted EPS, b) the biomass extracted from EPS, and c) the intact biomass with EPS by comparing the amount of sorbed REEs. Maximum adsorption capacities for the tested REEs of extracted EPS were 123.9-138.2 mg g-1 for Komarekiella sp. 89.12, 133.1-137.4 mg g-1 for Desmonostoc muscorum 90.03, and 103.5-129.3 mg g-1 for Nostoc sp. 20.02. A comparison of extracted biomass with intact biomass showed that 16% (Komarekiella sp. 89.12), 28% (Desmonostoc muscorum 90.03), and 41% (Nostoc sp. 20.02) of REE adsorption was due to the biosorption of the extracellular EPS. The glucose- rich EPS (15%-43% relative concentration) of all three strains grown under nitrogen-limited conditions showed significantly higher biosorption rates for all REEs. We also found a significantly higher maximum adsorption capacity of all REEs for the extracted EPS compared to cells without EPS and untreated biomass, highlighting the important role of the EPS as a binding site for REEs in the biosorption process. EPS from cyanobacteria could thus be used as efficient biosorbents in future applications for REE recycling, e.g., industrial process water and wastewater streams.

Remediation of groundwater pollution using photocatalytic membrane reactors

Recalcitrant pollutants in groundwater and industrial wastewater streams are very dangerous for the environment and human health. The conventional water treatment processes are not capable to degrade/removing them due to their very high chemical stability. The photocatalytic membrane reactors represent a possible route for overcoming the limits present in the conventional ones. In this study, photocatalyst loaded mixed matrix membranes (PMMM) were prepared using non solvent induced phase inversion process and titanium dioxide as a photocatalyst. SEM and EDX analyses, contact angle, and tensile strength measurements were used for characterizing the membranes. Their catalytic activity was assessed using the methyl orange as a recalcitrant pollutant. The photoactivity of the PMM membranes increased with the TiO2 content. The membrane loaded with the 2.5 wt % of titanium dioxide achieved better degradation and retained high degradation efficiency after 4 cycles, indicating the stability of the membrane.

On-Site Pilot-Scale Microalgae Cultivation Using Industrial Wastewater for Bioenergy Production: A Case Study towards Circular Bioeconomy.

This case study assesses the valorization of industrial wastewater streams for bioenergy generation in an industrial munition facility. On-site pilot-scale demonstrations were performed to investigate the feasibility of algal growth in the target wastewater on a larger outdoor scale. An exploratory field study followed by an optimized one were carried out using two 1000 L open raceway ponds deployed within a greenhouse at an industrial munition facility. An online system allowed for constant monitoring of operational parameters such as temperature, pH, light intensity, and dissolved oxygen within the ponds. The original algal seed evolved into an open-air resilient consortium of green microalgae and cyanobacteria that were identified and characterized successfully. Weekly measurements of the level of nutrients in pond liquors were performed along with the determination of the algal biomass to quantitatively evaluate growth yields. After harvesting algae from the ponds, the biomass was concentrated and evaluated for oil content and biochemical methane potential (BMP) to provide an estimate of the algae-based energy production. Additionally, the correlation among biomass, culturing conditions, oil content, and BMP was evaluated. The higher average areal biomass productivity achieved during the summer months was 23.9 ± 0.9 g/m2d, with a BMP of 350 scc/gVS. An oil content of 22 wt.% was observed during operation under low nitrogen loads. Furthermore, a technoeconomic analysis and life cycle assessment demonstrated the viability of the proposed wastewater valorization scenario and aided in optimizing process performance towards further scale-up.

Degradation of Aniline & Para- Chloroaniline from Water by Adsorption Coupled with Electrochemical Regeneration

Treatment methods for water-containing organics are gaining significant attraction in modern-day research. Amines are an important organic compound class encountered in industrial wastewater streams. The current research paper focuses on studying the adsorption behavior of aniline and parachloro-aniline using a graphite-based adsorbent, namely, Nyex-1000, and the subsequent regeneration of the adsorbent. To determine Nyex-1000's adsorption capacity, several parameters, including time, pH, and concentration, were assessed. Adsorption isotherms, kinetics, and used adsorbent regeneration were also investigated. The adsorption of aniline and parachloro-aniline was found to be quite rapid owing to its non-porous nature. Moreover, the low energy requirement makes the process quite economical due to the high electrical conductivity of the adsorbent. The adsorption data was fitted to Langmuir, Freundlich, Redlich Peterson, Sips, and Toth isotherm models. In aniline’s case, Langmuir and Parachloro-aniline Sips models gave the best fitting with the highest R2 value. A regeneration efficiency of 100% was observed in case of both aniline and parachloro-aniline by passing a charge of 5 and 10 coulombs per gram through the adsorbent bed 10 mm in thickness. Adsorption for parachloro-aniline was found to be 0.88 mg/g, and for aniline was found to be 0.40 mg/g. The reduction in adsorption capacity was minimal after several adsorption and regeneration cycles. This study found that spent adsorbent could be regenerated effectively through electrochemical regeneration.

Integration of Real Industrial Wastewater Streams to Enhance Chlorella vulgaris Growth: Nutrient Sequestration and Biomass Production

Integration of Real Industrial Wastewater Streams to Enhance Chlorella vulgaris Growth: Nutrient Sequestration and Biomass Production

Degradation of Organic Methyl Orange (MO) Dye Using a Photocatalyzed Non-Ferrous Fenton Reaction

Removal of recalcitrant organic pollutants by degradation or mineralization from industrial waste streams is continuously being explored to find viable options to apply on the commercial scale. Herein, we propose a titanium nanotube array (based on a non-ferrous Fenton system) for the successful degradation of a model contaminant azo dye, methyl orange, under simulated solar illumination. Titanium nanotube arrays were synthesized by anodizing a titanium film in an electrolyte medium containing water and ethylene glycol. Characterization by SEM, XRD, and profilometry confirmed uniformly distributed tubular arrays with 100 nm width and 400 nm length. The non-ferrous Fenton performance of the titanium nanotube array in a minimal concentration of H2O2 showed remarkable degradation kinetics, with a 99.7% reduction in methyl orange dye concentration after a 60 min reaction time when illuminated with simulated solar light (100 mW cm-2, AM 1.5G). The pseudo-first-order rate constant was 0.407 µmol-1 min-1, adhering to the Langmuir-Hinshelwood model. Reaction product analyses by TOC and LC/MS/MS confirmed that the methyl orange was partially fragmented, while the rest was mineralized. The facile withdrawal and regeneration observed in the film-based titanium nanotube array photocatalyst highlight its potential to treat real industrial wastewater streams with a <5% performance drop over 20 reaction cycles.

In-situ growth of ZIF-8 nanocrystals on biochar for boron adsorption

Removing boron (B) from aqueous solution is economically and environmentally important in the treatment of many industrial and agricultural wastewater streams. Here, we produced canola straw-derived biochar (BC), a low-cost and green adsorbent, as a template to prepare a BC/ZIF-8 (zeolite-like imidazolate framework) composite material. We then performed a series of batch experiments and material characterization to evaluate the adsorption processes and practical applications of the material. The results showed that the maximum adsorption capacity of BC/ZIF-8 for B from a low total dissolved solids (TDS) aqueous solution was 44 mg g-1 (adsorbent dosage is 0.5 g L−1, pH=6, C0 =300 mg L-1). Compared to ZIF-8 alone, the adsorption capacity of B to BC/ZIF-8 increased by 76%. In the adsorption tests conducted in the low TDS solution, the adsorption process was well-represented using a pseudo-first-order kinetics model and the Langmuir adsorption isotherm. Through six regeneration cycles, we demonstrated that BC/ZIF-8 remains a robust sorbent for B. Hydraulic fracturing (HF), a key technology for oil and gas stimulation, produces a large amount of flowback and produced water (FPW). BC/ZIF-8 was used to remove boron from FPW, achieving a maximum adsorption capacity of 15.45 mg g-1 (C0 =42 mg L-1), 5.99% lower than that of pure B solution with similar conditions. Physicochemical characterization of BC/ZIF-8 showed that it has a stable structure and suggested that B adsorption to BC/ZIF-8 was primarily due to hydrogen bonding and electrostatic attraction between B(OH)4- and the positively charged BC/ZIF-8 at pH < PZC. Our study shows that BC-based metal-organic frameworks (MOFs) have the potential for broader industrial applications and water treatment.

Development of Ag-dendrites @Cu nanostructure for removal of selenium (IV) from aqueous solution.

Removal of selenite (Se (IV)) from wastewater is vital due to its more toxic and mobile properties. In this study, a novel dendritic silver-dendrites@ copper with hierarchical side-branches were synthesized through a two-pot rapid, facile, and green precipitation route. Characterization of the dendrites by transmission electron microscope (TEM), scanning electron microscope (SEM), dynamic light scattering (DLS), and X-ray diffraction spectroscopy (XRD) confirmed the proper preparation of dendritic AgCu nanostructure. Significantly, the Ag@Cu nanostructure has high specific surface area (150 m2/g) and excellent adsorption activity toward selenite. The adsorption rate of Se (IV) on the dendritic AgCu reaches 94% within 60 min under normal adsorption procedures. Both adsorption kinetics and isotherms have been described well by the pesudo-second order model and Langmuir model, respectively. The noticeable high adsorption capabilities can mainly accredit to the effect of the hierarchical side-branched structure. Therefore, the dendritic AgCu nanostructure has a room of treating heavy metals-contaminated industrial wastewater streams. PRACTITIONER POINTS: Silver-dendrites@ copper with hierarchical side-branches were synthesized through a rapid and green precipitation route using copper nanoparticles. The prepared nanostructure was applied for Se (IV) adsorption at varying operational conditions (contact time, pH, and dose). High adsorption capacity for Se (IV) up to 173.1 mg/g was achieved using the prepared nanoparticles applying Langmuir isotherm model.

Utilization of Different Carbon Sources by Nordic Microalgae Grown Under Mixotrophic Conditions

Microalgae are promising candidates for sustainable wastewater treatment coupled to the production of biofuel, bioplastic and/or bio-fertilizers. In Nordic countries, however, light is a limiting factor for photosynthesis and biomass production during the winter season. Compared to municipal wastewater, industrial wastewater streams from the pulp and paper industry contain lower amounts of nitrogen, but high concentrations of carbon sources, which could be utilized by microalgae to enhance biomass production in limiting light. This study focused on the utilization of methanol, glycerol and xylose by five different Nordic microalgae [Chlorella vulgaris (13–1), Coelastrella sp. (3–4), Desmodesmus sp. (2–6), Chlorococcum sp. (MC1) and Scotiellopsis reticulata (UFA-2)] grown under mixotrophic conditions. Two of these strains, i.e., Chlorococcum sp. (MC1) and Scotiellopsis reticulata (UFA-2) were able to grow in the presence of xylose or methanol at concentrations of 6 g L–1, or 3%, respectively, in a 12/12 h day/night cycle. HPLC analysis confirmed the consumption of those substrates. Glycerol (2.3 g L–1) was tolerated by all strains and increased growth for Chlorella vulgaris (13–1), while higher concentrations (20 g L–1) were only tolerated by Chlorococcum sp. (MC-1). Fourier-transform infrared spectroscopy, performed after growth in presence of the dedicated carbon source, indicated an increase in the fingerprint region of the carbohydrate fraction. This was particularly the case for Chlorococcum sp. (MC1), when grown in presence of glycerol, and Scotiellopsis reticulata (UFA-2), when grown in presence of xylose. Therefore, these strains could be potential candidates for the production of biofuels, e.g., bioethanol or biogas. We could show that Nordic microalgae are able to grow on various carbon sources; the actual uptake rates are low during a 12/12 h day/night cycle requesting additional optimization of the cultivation conditions. Nonetheless, their potential to use pulp and paper waste-streams for cheap and sustainable biomass production is high and will support the development of new technologies, turning waste-streams into resources in a circular economy concept.

Recovery of precious metals from industrial wastewater towards resource recovery and environmental sustainability: A critical review

Nowadays, the recovery processes of precious metals (PMs) from industrial wastewater streams have found significant attractions among various investigators worldwide. PMs are known as rare/noble chemical elements that their fundamental characteristics such as ductility, electrical conductivity, and resistance against corrosion have made them promising for application in industrial-based activities such as jewelry, petrochemistry, and catalysis. The main objective of this review paper is to provide an opportunity for expert as well as non-expert readers to be familiar with the state-of-the-art breakthroughs in the recovery of PMs (i.e., gold (Au), silver (Ag), platinum (Pt), palladium (Pd), ruthenium (Ru), rhodium (Rh), iridium (Ir), osmium (Os), Rhenium (Re) and so on.) from wastewater streams. Apart from the explanation of industrial applications, the recovery process of PMs using various approaches is aimed to be interpreted comprehensively. Eventually, the advantages and disadvantages of applied techniques for the recovery of PMs are discussed, and different approaches as well as future perspectives towards their sustainable use are introduced.

Aspergillus caespitosus ASEF14, an oleaginous fungus as a potential candidate for biodiesel production using sago processing wastewater (SWW)

BackgroundOleaginous microorganisms are sustainable alternatives for the production of biodiesel. Among them, oleaginous fungi are known for their rapid growth, short life cycles, no light requirement, easy scalability, and the ability to grow in cheap organic resources. Among all the sources used for biodiesel production, industrial wastewater streams have been least explored. We used oleaginous fungi to decontaminate sago processing wastewater and produce biodiesel.ResultsAmong the 15 isolates screened for lipid production and starch utilization using the Nile red staining assay and amylase plate screening, three isolates accumulated > 20% (w/w) of their dry cell mass as lipids. The isolate ASEF14 exhibited the highest lipid accumulation (> 40%) and was identified as Aspergillus caespitosus based on the 28S rRNA gene sequencing. The maximum lipid content of 54.4% in synthetic medium (SM) and 37.2% in sago processing wastewater (SWW) was produced by the strain. The Fourier-transform infrared (FTIR) spectroscopy of the fungal oil revealed the presence of functional peaks corresponding to major lipids. Principal component analysis (PCA) of the FTIR data revealed major changes in the fatty acid composition during the transition from the growth phase (Days 1–3) to the lipid accumulation phase (Days 4–7). The fatty acid methyl esters (FAME) analysis of fungal oil from SWW contained 43.82% and 9.62% of saturated and monounsaturated fatty acids, respectively. The composition and percentage of individual FAME derived from SWW were different from SM, indicating the effect of nutrient and fermentation time. The fuel attributes of the SM- and SWW-grown fungal biodiesel (kinematic viscosity, iodine value, cetane number, cloud and pour point, linolenic acid content, FA > 4 double bonds) met international (ASTM D6751, EN 14214) and national (IS 15607) biodiesel standards. In addition to biodiesel production, the strain removed various contaminants such as total solids (TS), total suspended solids (TSS), total dissolved solids (TDS), dissolved oxygen (DO), chemical oxygen demand (COD), biological oxygen demand (BOD), total nitrogen (TN), total phosphorus (TP), and cyanide up to 58.6%, 53.0%, 35.2%, 94.5%, 89.3%, 91.3%, 74.0%, 47.0%, and 53.84%, respectively, from SWW.ConclusionThese findings suggested that A. caespitosus ASEF14 is a potential candidate with high lipid accumulating ability (37.27%), capable of using SWW as the primary growth medium. The medium and incubation time alter the FAME profile of this fungus. The physical properties of fungal oil were in accordance with the biodiesel standards. Moreover, it decontaminated SWW by reducing several polluting nutrients and toxicants. The fungal biodiesel produced by this cost-effective method could serve as an alternate path to meet global energy demand.

Treatment of real industrial-grade dye solutions and printing ink wastewater using a novel pilot-scale hydrodynamic cavitation reactor

A novel pilot-scale hydrodynamic cavitation (HC) reactor was used to decolorize industrial-grade dye solutions and printing ink wastewater (PIW). The effect of the orifice plate geometry (1 hole plate of 1 mm and 2 mm in diameter, 31 holes of 1 mm and 2 mm in diameter, 62 holes of 1 mm and 2 mm in diameter), inlet pressure (4, 5 bar), initial dye concentration (0.3 and 0.6 OD), and the synergistic effect of HC and hydrogen peroxide concentration (0.0, 0.5, 1.0, 2.0 g/L) were investigated. The results showed that the highest color removal was obtained using 31 holes orifice plate of 2 mm holes’ diameter, at 4 bar inlet pressure. Furthermore, although HC could not degrade completely all the industrial-grade dyes, efficiency was enhanced in the presence of H2O2. The optimum concentration of hydrogen peroxide was 1.0 g/L regardless of the initial concentration of the dyes studied. Under optimum operating conditions, color removal reached up to 68% for black, 39% for red, 43% for yellow, 55% for green, and 51% for cyan dye, while color removal in the PIW reached only 15%. The black dye solution presented almost 100% COD removal, while 38%, 25%, 67%, and 78% COD removal values were obtained for the red, yellow, cyan and green dyes, respectively. 55% COD removal was recorded from the PIW. Concerning cavitation yields, black, red, yellow, green, cyan dye yields reached 2.5E(-7), 1.1E(-7), 1.5E(-7), 2.0E(-7), 1.7E(-7) OD⋅L/J, respectively, while PIW yield was 6.3E(-8) OD⋅L/J. The present study demonstrates that HC combined with green oxidants such as hydrogen peroxide could be an alternative treatment approach for real industrial wastewater streams. However, a combination with a post-treatment method should be applied to maximize both color and COD removal.

Modeling and simulation of a hybrid system of trickle bed reactor and multistage reverse osmosis process for the removal of phenol from wastewater

Phenol is one of the most toxic and harmful pollutants in industrial wastewater streams, the removal of which is therefore of critical importance. The use of reverse osmosis (RO) systems as a means of treating wastewater is continuously growing. This research investigates the effect of operating parameters on the performance of five different multistage RO configurations coupled with a trickle bed reactor (TBR) using model-based simulation. The results were compared, and an analysis was then performed to identify which hybrid TBR and multistage RO arrangement rejected the most phenol content. The basis for comparison was four performance metrics of permeate concentration, rejection, recovery, and specific energy. The study found that the flow rate and concentration have little effect on the operation unless there is a concurrent increase of both. It was also found that the four-performance metrics used were interlinked and affect the quality and quantity of the final freshwater product.

Utilization of hydrochar derived from waste paper sludge through hydrothermal liquefaction for the remediation of phenol contaminated industrial wastewater

Abstract Hydrothermal liquefaction derived hydrochar produced from industrial paper sludge was used as an adsorbent to remove phenol derivatives from an industrial wastewater stream. Removal efficiency for phenol was determined using synthetic solutions (10–150 ppm) using batch adsorption experiments at a constant solution pH (8), temperature (25 ± 2 °C) and rotary speed (150 rpm). The adsorption of phenol onto hydrochar followed a Freundlich isotherm and could be described with pseudo-second-order kinetic models. Analysis of the adsorption mechanisms showed that particle film mass transport was the rate-determining step in the adsorption process. A COD removal efficiency of 31 ± 1% was achieved for the industrial wastewater stream. All phenol components in the wastewater stream could be removed, but not all organic acids and cyclic ketones. The performance of the paper sludge-based hydrochar compared well with that of activated carbon (44% COD removal). The final phenol concentration in the wastewater stream was below the acceptable phenol concentration for industrial effluents (1 mg/L). The results show that paper sludge can be converted to a valuable marketable commodity that could reduce waste management costs for a paper mill, while also reducing the cost of expensive adsorbents.

The existing technology and the application of digital artificial intelligent in the wastewater treatment area: A review paper

Wastewater treatment using various existing technologies, including advanced oxidation processes, adsorption, and membrane separation for various pollutants removal from industrial and municipal wastewater streams, is an essential aspect of reaching environmental sustainability to keep human well-being and healthy economic growth. However, some challenging elements along with the wastewater treatment process affect pollutant removal efficiency and other resources. This condition will lead to various uncertainty in the wastewater treatment system related to the fluctuations in the quality of treated water and wastewater, operation costs, and environmental risk. Artificial intelligence can then be such a reliable solution to predict and minimize those complications and optimize the process and parameters implemented in the wastewater treatment system.