An L-glutathione-functionalized silica adsorbent was applied in this study to remove malathion from aqueous media. This adsorbent has demonstrated an improved adsorption efficiency of malathion. The maximum uptake achieved was 130 mg g−1 at pH 8. Equilibrium was reached after about 90 min. A pseudo-second-order model best described the adsorption kinetics. The adsorption isotherms were best simulated by the Freundlich model. The functional groups are thermally stable up to about 150 °C. The elemental analysis results indicated high glutathione ligand densities. The results of this study show that the environmentally friendly L-glutathione functionalized silica is a promising candidate for the removal of malathion from water at the industrial level.

Research on the use of microbial biosensors for monitoring wastewater contaminants is a topic that covers few publications compared to their applicability in other fields, such as biomedical research. For this reason, a systematic analysis of the topic was carried out, for which research-type articles were reviewed during the period 2012 to September 2022. For this, different search platforms were used, including PubMed, ScienceDirect, Springer Link, and Scopus, and through the use of search equations a relevant bibliography was located. After that, the research articles were selected based on exclusion criteria. As a result, it was found that, of the 126 articles, only 16 articles were strictly related to the topic, since there was a duplication of articles among the different databases. It was possible to demonstrate the usefulness of microorganisms as components of biosensors to monitor BOD, heavy metals, and inorganic contaminants in wastewater that also had a high sensitivity. Add... [more]

Constructed wetlands (CW) is an environmentally friendly technique for removing pollutants from wastewater and has been applied to municipal wastewater, petroleum refinery wastewater, agriculture drainage, acid mine drainage, etc. The past decade has seen a remarkable number of innovations in the exponentially growing field of microbiology. This manuscript covers a critical review of key aspects of CW, such as various types of CW, the contaminants and their removal mechanisms, degradation pathways, challenges and opportunities, materials, applications, and theory with a focus on recent advances in the last three decades. In addition, an attempt has been taken to project future advances in the field of CW and facilitate these advances by framing key unsolved problems in CW. Guidelines are prepared for the fast-growing CW field through the standardization of key design aspects. This review covers the evaluation of the current state-of-the-art of CW technology and provides definitions and... [more]

The paper describes a new, proprietary method of HS extraction from digested sewage sludge. HS was extracted using the processes of dissolving organic substances and precipitating mineral micropollutants. The obtained substances were tested by determining their IR spectrum, elemental composition, and content of micropollutants and comparing them with HS obtained using the classical method. Using Phytotestkit, it was shown that HSs isolated from digested sewage sludge contain relatively large amounts of the nutrients necessary for plants (including N and P) and are a good component of a biostimulating substance. The obtained HS contains more ammonium and phosphorus ions. During extraction, inorganic impurities (including heavy metals) are reduced, and the humic product does not contain pathogens, parasites, and their spores. The method is simple, economically justified, and can be used on an industrial scale.

As non-renewable resource, the recovery and utilization of phosphorus from wastewater is an enduring topic. Stimulated by the advances in research on polyphosphates (polyP) as well as the development of Enhanced Biological Phosphorus Removal (EBPR) technology to achieve the efficient accumulation of polyP via polyphosphate accumulating organisms (PAOs), a novel phosphorus removal strategy is considered with promising potential for application in real wastewater treatment processes. This review mainly focuses on the mechanism of phosphorus aggregation in the form of polyP during the phosphate removal process. Further discussion about the reuse of polyP with different chain lengths is provided herein so as to suggest possible application pathways for this biosynthetic product.

This research investigated the ability of two materials, which are waste generated during water treatment and wastewater treatment, to remove phosphates from water. The selected materials were quartz sand used in drinking water treatment plants (OQS) and incinerated (600 °C) sewage sludge (ISS). The materials were chosen for their composition: both contain aluminium, iron, and calcium. The experiments were carried out in the laboratory (in batch and in columns stand). Modelling of the sorption processes was performed on the basis of results from experiments in batches. The maximum adsorption capacity of the OQS was 1.14 mg/g obtained using the linearized Langmuir model and the maximum adsorption capacity of the ISS was 0.86 mg/g for the linearized Langmuir model (in batch). A pseudo-first-order model obtained using a nonlinear fit can accurately explain phosphate adsorption kinetics using both adsorbents: OQS and ISS. During the column filtration experiment, a higher sorption capacity... [more]

A degradation study of diazepam (DZP) in aqueous media by gamma radiation, high frequency ultrasound, and UV radiation (artificial-solar), as well with each process intensified with oxidizing agents (H2O2 and Fenton reagent) was performed. The parameters that influence the degradation of diazepam such as potency and frequency, irradiation dose, pH and concentration of the oxidizing agents used were studied. Gamma radiation was performed in a 60Co source irradiator; an 11 W lamp was used for artificial UV radiation, and sonification was performed at frequency values of 580 and 862 kHz with varying power values. In the radiolysis a 100% degradation was obtained at 2500 Gy. For the sonolysis, 28.3% degradation was achieved after 180 min at 862 kHz frequency and 30 W power. In artificial photolysis, a 38.2% degradation was obtained after 300 min of UV exposure. The intensification of each process with H2O2 increased the degradation of the drug. However, the best results were obtained by co... [more]

An experimentally validated CFD model was developed for lab-scale arsenic (As) fixed-bed columns using COMSOL Multiphysics. The effects of key factors such as the adsorbent bed depth, the feed flow rate, and the initial As concentration (conc.) on the overall As removal performance were investigated. Subsequently, the CFD was combined with response surface methodology (RSM) to optimize process conditions and examine main and interaction effects of these factors on model responses, i.e., the As removal efficiency and the bed saturation time. The ANOVA results suggested that quadratic regression models were highly significant for both responses. The established regression model equations predicted the response values closer to CFD measurements. It was found that, compared with the initial As conc. and the feed flow rate, the effect of the bed depth was more significant. Moreover, both the As removal efficiency and the bed saturation time were increased reasonably with the increasing bed... [more]

Wastewater disinfection is one of the most critical issues in protecting human health against exposure to waterborne pathogenies. Chlorine is among the most commonly used disinfectants in many wastewaters’ treatment plants. Nevertheless, disquiets regarding chlorine’s disinfection by-products (DBPs) have grown recently. One of the most effective ways to reduce DBPs generation is to reduce chlorine dosage by increasing disinfectant efficiency. Using magnetic field (MF) in wastewater treatment is one of the promising research topics with significant progression. This study aimed to evaluate the efficiency of using a magnetic field and/or sodium hypochlorite (NaClO) disinfection on secondary slaughterhouse wastewater effluent quality and by-products. Three groups of secondary slaughterhouse wastewater effluents were used: G1 was treated with NaClO only at 0, 2, 4, and 6 mg/L; G2 was treated with exposure to MF at 14,500 gausses, and G3 was pretreated with MF, then NaClO at the exact chlor... [more]

The environmental pollution due to wastewater, especially domestic wastewater, is becoming more serious. Thus, this study was performed to assess the removal of pollutants by the combination of wetland technology, specifically constructed wetland (CW), with Para grass (Brachiaria mutica) together with the adsorption of red sludge. With an organic loading rate (OLR) of 120 (kg COD/ha/day), the treatment efficiency for wastewater in this study is quite high and the concentrations of parameters in the effluent were lower than the limits established by the QCVN 14:2015/BTNMT for domestic wastewater, which indicated the feasibility of this combination. These results are expected to open the possibilities of using environmentally friendly processes for wastewater treatment in urban and industrial areas.

Emerging contaminants (ECs) include a diverse group of compounds not commonly monitored in wastewaters, which have become a global concern due to their potential harmful effects on aquatic ecosystems and human health. In the present work, six ECs (ibuprofen, diclofenac, erythromycin, triclosan, imidacloprid and 17α-ethinylestradiol) were monitored for nine months in influents and effluents taken from four wastewater treatment plants (WWTPs). Except for the case of ibuprofen, which was in all cases in lower concentrations than those usually found in previous works, results found in this work were within the ranges normally reported. Global removal efficiencies were calculated, in each case being very variable, even when the same EC and facility were considered. In addition, the SimpleTreat model was tested by comparing simulated and real ibuprofen, diclofenac and erythromycin data. The best agreement was obtained for ibuprofen which was the EC with the highest removal efficiencies.

The special features of metal−organic frameworks (MOFs), namely, tunable porosity, exceptional structure, high surface area and high adsorption capability enable them to be widely studied in many applications including carbon capture and storage (CCS), biomedical engineering, catalysis and pollutant treatment. Despite these remarkable properties, MOFs are known to be moisture-sensitive, hardly recyclable and expensive in fabrication cost which limits their breakthrough performance in more efficient uses. Recently, extensive studies have been devoted to counter those shortcomings by embedding MOFs with support materials using various series of synthetic designs to yield incorporated MOF hybrid materials to counter their limitations. In view of this interest, this review summarizes the latest developments of incorporated MOFs with various materials, namely, ionic liquids (ILs), membranes and metal species. Pre-synthetic and post-synthetic synthesis methods are also discussed. This review... [more]

The contamination of surface and groundwater is of major concern around the globe due to the fast industrialization and urbanization. The groundwater and water quality of rivers, Ravi and Chenab in Faisalabad, Pakistan are contaminated due to the industrial wastewater. The aim of this study was the assessment of the physiochemical contaminants of Faisalabad’s industrial wastewater area and the adsorptive removal of ions present in high concentrations following the National Environmental Quality Standards (NEQS) for the municipal and industrial liquid effluents of Pakistan. One of the two samples was collected from a drain carrying wastewater from different industries and other from the outlet of a drain discharging wastewater into river Chenab. The analysis results obtained indicate that most of the contaminants were below the acceptable limit of industrial wastewater NEQS, Pakistan. However, contaminants like sulfate ions (714 mg/L), total dissolved solids (33,951−34,620 mg/L) and bar... [more]

The need arises to seek new depuration technological responses aimed at the reuse of wastewater, which requires the development and promotion of economically and environmentally sustainable technologies. In this paper, it studies an improvement to a disinfection system sustainable, low-cost, patented in 2019, and based on solar energy. The water passes through a canal of reflective material in the continuous regime, and in the batch regime, the water remains in the canal. The panels are located parallel to the lateral faces of the canal. The fraction of the radiation reflected outside the canal reaches the reflective side panels that return the radiation to the canal. These panels concentrate the radiation in the canal through reflection. The disinfectant canal with fins and side panels uses ultraviolet radiation to eliminate the bacterial load carried by treated wastewater. For this reason, the present work analyzes the incidence in the area of influence of the disinfectant canal. Whe... [more]

Microalgae are photoautotrophic microorganisms capable of producing compounds with potential bioenergetic applications as an alternative energy source due to the imminent exhaustion of fossil fuels, their impact on the environment, and the constant population increase. The mass cultivation of these microorganisms requires high concentrations of nutrients, which is not profitable if analytical grade culture media are used. A viable alternative is the use of agro-industrial wastewater, due to the metabolic flexibility of these microorganisms and their ability to take advantage of the nutrients present in these substrates. For the reasons mentioned above, the effect of the cultivation in wastewater from cheese processing on the growth parameters and biomass composition of Scenedesmus sp. was evaluated, and its nutrient removal capacity determined. A high lipid concentration was obtained in the cultures with the dairy effluent (507.81 ± 19.09 mg g−1) compared to the standard culture medium... [more]

Currently, the rapid development of industry leads to an increase in negative anthropogenic impacts on the environment, including water ecosystems. This circumstance entails toughening environmental standards and, in particular, requirements for the content of pollutants in wastewater. As a result, developing technical and cost-effective ways for wastewater purification becomes relevant. This study is devoted to the development of a novel composite sorbent, based on polyvinyl butyral and potassium polytitanate, designed to purify water from heavy metal ions. The co-deposition of a mixture based on a polymer solution and a filler suspension was used to obtain a composite material. In this work, the influence of the deposition conditions on the structure and properties of the resulting composites was studied, as well as the optimal ratio of components, including solvent, precipitant, polymer binder, and filler, were established. In the course of this study on the sorption properties of t... [more]

Phosphates in wastewater at elevated concentrations cause eutrophication of water bodies and their removal from treated wastewater is essential before effluents are discharged to the environment. Phosphates are predominately removed during wastewater treatment by chemical precipitation which is usually expensive and has a significant environmental footprint. The purpose of this study was to investigate the effectiveness of waste recycled bricks as adsorbent for phosphate removal during wastewater treatment. The kinetics, isotherms, and thermodynamics of adsorption were investigated to establish the mechanisms of adsorption. The results showed that adsorption capacities increased with an increase in contact time, adsorbent dosage, and initial phosphate concentration. The kinetic study indicated that adsorption was governed by several mechanisms with various processes dominating different stages of the adsorption. The adsorption process was better represented by the pseudo-second-order k... [more]

This work is a review of scientific papers on the influence of temperature (T) on the biosorption of various dyes from aqueous solutions and wastewaters. The dyeing process of textiles is usually carried out at high temperatures, and therefore, the wastewater generated there when entering the treatment plant may still be hot. Hence, depending on the climatic conditions of a given region, the biosorption method used for their purification may occur at various temperatures. Most of the papers clearly stated the positive influence of T on biosorption, generally indicating the chemical nature of this process. At the same time, substantial number of authors confirmed the positive effect of T on the biosorption with an initial T-rise from approximately 20 °C to about 30−40 °C range; conversely, at higher temperatures, they indicated a decrease in the biosorption efficiency. Additionally, many authors clearly implied the negative impact of T on the biosorption parameters. They generally envis... [more]

The stimulation of renewable fuel production is related to the environmental issues resulting from the extraction and utilization of fossil fuels. Although corn-based ethanol is one of the leading renewable fuels and promises to mitigate these environmental impacts, it generates large volumes of wastewater with high concentrations of organic material (CODcr > 30,000 mg/L) and low pH (3.5−4.5), which leads to serious environmental concerns. A common method of treatment of distillery wastewater is the Dry Distilled Grain Soluble (DDGS) process, which separates liquid and solid fractions; however, a disadvantage of this process is its high energy consumption. Other commonly implemented methods are often costly and not environmentally safe. To minimize these problems, a flocculation process can be applied as a potential lower energy consumption process utilizing bioflocculants, which have been proven harmless to the environment. Therefore, the main goal of this study was to analyze the eco... [more]

Anaerobic digestion has been widely employed in waste treatment for its ability to capture methane gas released as a product during the digestion. Certain wastes, however, cannot be easily digested due to their low nutrient level insufficient for anaerobic digestion, thus co-digestion is a viable option. Numerous studies have shown that using co-substrates in anaerobic digestion systems improve methane yields as positive synergisms are established in the digestion medium, and the supply of missing nutrients are introduced by the co-substrates. Nevertheless, large-scale implementation of co-digestion technology is limited by inherent process limitations and operational concerns. This review summarizes the results from numerous laboratory, pilot, and full-scale anaerobic co-digestion (ACD) studies of wastewater sludge with the co-substrates of organic fraction of municipal solid waste, food waste, crude glycerol, agricultural waste, and fat, oil and grease. The critical factors that infl... [more]

This research dealt with the impact of the quality of the water source on the mechanical properties of construction materials. The mechanical properties of construction materials include compressive, tensile, and flexural strength. Water samples were collected from different resources, these samples were then synthetically investigated to identify and compare their quality parameters. After a detailed chemical analysis of water samples from three sources—wastewater, surface or canal water, and ground water—construction concrete material samples were prepared. The construction materials were developed with the same water−cement ratio, i.e., 0.60 for each concrete mix sample at two mix ratios—M1 (1:2:4) and M2 (1:1.5:3). Slump cone and compacting factor tests were conducted on the fresh concrete to determine its workability prior to its hardening. Then, at 7, 14, 21, and 28 days for each mix, tests for mechanical properties were carried out to determine the compressive, tensile, and flex... [more]

The use of flotation for the treatment of wastewaters in general, but especially for the removal of oil, grease, general organic matter, and suspended solids, is well established as a low energy process. Polyelectrolytes (PEs) can enhance performance without adding to the solids load that occurs with inorganic additives such as alum. The bridging of pollutants and the attachment of the resulting aggregates to the air-water interface can be effectively carried out with most wastewaters. Hydrophobic modification of the PEs can be useful for difficult species. It should be applied to the flotation of polyfluoroalkyl substances, for example, as they are not amenable to economical conventional treatment. Similarly, the removal of microplastic particles from sewage effluents by flotation could be enhanced.

This study is conducted to investigate the characteristics of outflow wastewater of the 1 m³ on-site wastewater treatment unit on the basis of the testing and measurement data of the samples that were taken during the study monitored period (August 2017 to January 2018). For this purpose, samples were taken on a weekly basis from the treated wastewater effluent and five quality parameters (biochemical oxygen demand (BOD), chemical oxygen demand (COD), total suspended solids (TSS), pH, E-coli counts) were monitored and measured. The average values of the five parameters were compared with the Jordanian standard maximum values, and water reuse in irrigation of plants classifications have been assessed and investigated. Average values of BOD, COD, TSS, pH, and E-coli in treated wastewater were 11 mg/L, 104 mg/L, 15 mg/L, 7.51, and 387 counts, respectively. The installation of in-line ultraviolet (UV) unit in recirculating delivery system played a vital role in the reduction of counts far... [more]

Aerobic granular sequencing batch reactors (SBRs) are usually inoculated with activated sludge which implies sometimes long start-up periods and high solids concentrations in the effluent due to the initial wash-out of the inoculum. In this work, the use of aerobic mature granules as inoculum in order to improve the start-up period was tested, but no clear differences were observed compared to a reactor inoculated with activated sludge. The effect of the aeration rate on both physical properties of granules and reactor performance was also studied in a stable aerobic granular SBR. The increase of the aeration flow rate caused the decrease of the average diameter of the granules. This fact enhanced the COD and ammonia consumption rates due to the increase of the DO level and the aerobic fraction of the biomass. However, it provoked a loss of the nitrogen removal efficiency due to the worsening of the denitrification capacity as a consequence of a higher aerobic fraction.

As the demand for textile products and synthetic dyes increases with the growing global population, textile dye wastewater is becoming one of the most significant water pollution contributors. Azo dyes represent 70% of dyes used worldwide, and are hence a significant contributor to textile waste. In this work, the removal of a reactive azo dye (Reactive Orange 16) from water by adsorption with chitosan grafted poly(poly(ethylene glycol) methyl ether methacrylate) (CTS-GMA-g-PPEGMA) was investigated. The chitosan (CTS) was first functionalized with glycidyl methacrylate and then grafted with poly(poly(ethylene glycol) methyl ether methacrylate) using a nitroxide-mediated polymerization grafting to approach. Equilibrium adsorption experiments were carried out at different initial dye concentrations and were successfully fitted to the Langmuir and Freundlich adsorption isotherm models. Adsorption isotherms showed maximum adsorption capacities of CTS-g-GMA-PPEGMA and chitosan of 200 mg/g a... [more]