Industrial Wastewater Discharge Research Articles

Human activities contributing to the accumulation of high-risk trace metal(loid)s in soils of China's five major urban agglomerations

Rapid urbanization has accelerated the accumulation of trace metal(loid)s (TMs) in soils, but the relationship between this accumulation and human activities remains largely unknown. Therefore, based on 775 published literatures (2001–2020), this study aimed to identify the influence of human activities on TM accumulation. Results showed that all soil TM concentrations were higher than their corresponding Chinese soil background values. The pollution risk assessment indicated that the soil TMs in the study area were at moderate levels, and the value of Pollution load index was 2.10. According to the assessment of health risks, the non-carcinogenic risks for adults were at the “Negligible risk” level; while the carcinogenic risk was not negligible for all populations, with children being more susceptible than adults. Meanwhile, six high-risk TMs were identified based on the grading of Contaminating factors (CF ≥ 3) and contribution to health risk (≥ 75%), including four high pollution risk TMs (Cd, Hg, Cu, and Pb) and two high health risk TMs (Cr and As) . In addition, in accordance with the results of the Random forest model, the accumulation of soil high-risk TMs was closely related to influencing factors associated with human activities. The accumulation of Hg and Cr among five major urban agglomerations had the same influencing factors (the number of industrial companies and the amount of industrial wastewater discharge for Hg; the amount of pesticide application and highway mileage for Cr). However, there were significant differences in the factors influencing the accumulation of the other four high-risk TMs (including Cd, As, Cu and Pb), due to the different characteristics of each urban agglomeration. Our results provide new insights into the relationship between human activities and soil TM accumulation.

Decomposing the effect of technology on wastewater and related pollutants discharges in China

Technology assumes a pivotal role in both water conservation and pollution reduction. This study deconstructs technology into three categories: source water-saving technology (SST), process control technology (PCT), and end-of-pipe removal technology (ERT). Employing the extended IPAT and decomposition approach, it assesses the diverse impacts of these technologies on wastewater discharge in China. The findings reveal a notable decrease in industrial water consumption and wastewater discharge, yet a significant increase in the domestic sector. This increase is largely attributed to socio-economic factors. Nevertheless, the effects of SST, PCT, and ERT on wastewater discharge vary across sectors, pollutants, and regions. SST and ERT play a crucial role in diminishing industrial wastewater discharge, whereas PCT leads to an increase in approximately half of the regions. Moreover, SST and PCT tend to escalate domestic wastewater discharge in most regions, while ERT exerts a mitigating influence across the majority of regions.

Assessing coastal outfall impact on shallow enclosed bays water quality: Field and statistical analysis

Shallow bays, valued for their environmental, economic, and social significance, face increasing threats from anthropogenic stressors, primarily wastewater discharge through coastal outfalls. The slow tidal currents in these bays hinder the effective dispersion of pollutants to deeper waters, exacerbating their impact. This study assesses the spatial effects of wastewater and brine discharges on Sulaibikhat Bay's water quality. The approach combines fieldwork, laboratory analysis, and statistical techniques to identify pollutant types, sources, and concentrations near outfalls, nearshore, and offshore areas. Throughout the study, high water temperatures were observed consistently, exceeding 30 °C in summer and 18.6 °C in winter near most outfalls, with a maximum deviation from the ambient water of 11.1 °C recorded in December. In addition to elevated electrical conductivity (EC) levels peaking at 60,700 μs/cm, these elevated temperatures significantly reduce dissolved oxygen levels and have been linked to fish kill events in the Bay. NH3-N, TSS, COD, BOD5, FC, and FS concentrations exceeded allowable limits in 56.4 %, 92.25 %, 40.30 %, 32.1 %, 70 %, and 63.36 % of samples, respectively, often reaching extreme levels. Also, the BOD5/COD ratios suggest the presence of non-biodegradable organic matter, mainly from industrial sewage, and the FC/FS levels implicate human and animal waste. These results indicate a mix of domestic, industrial, and commercial wastewater discharges and underscore the severe threat coastal outfalls pose to ecosystem health and water quality in Sulaibikhat Bay. Principal Component Analysis (PCA) and Cluster Analysis (CA) delineate two distinct environmental zones with varying characteristics and contamination levels, necessitating expanded monitoring. Finally, substantial field research, numerical modeling, and establishing a sustainable environmental management system are needed to protect this fragile ecosystem. Also, converting outfalls into offshore may mitigate the environmental status of the bay by enhancing pollutant dilution and dispersion.

Anthropogenic trace metals in Setiu Wetland: Spatial and seasonal distribution and implications for environmental health

The growing urban wastewater volume poses a major global environmental challenge, especially in developing nations where inadequate treatment and discharge impact clean water availability. This study focused on Setiu Wetland, aiming to analyze seasonal and spatial variations of trace metals in particulate form from anthropogenic and pathogenic sources. Surface water samples were collected from multiple stations, measuring physical parameters like salinity, temperature, pH, dissolved oxygen (DO), and dissolved organic carbon (DOC). Samples were filtered using ultrafiltration and analyzed with inductively coupled plasma mass spectrometry (ICP-MS). Correlations between trace metals and other parameters were examined to understand their dynamics in the area. The study found that particulate trace metals were influenced by anthropogenic sources, including municipal, industrial, agricultural, and domestic wastewater discharge. The measured concentrations for Cd, Cu, Pb, Fe, and Zn were 10.9 ± 5.1, 31.8 ± 16.8, 72.5 ± 28.5, 20,206 ± 17,929, and 46,742 ± 30,898 μg/g, respectively, indicating their significant presence. To gain deeper insights, a model incorporating principal component analysis (PCA) analyzed the relationships between trace metals, dissolved oxygen levels, and factors like pH, temperature, salinity, and DOC. Regression techniques predicted Cd, Zn, and Fe concentrations based on salinity, with pH serving as an additional predictor for Cu. Moreover, Pb concentration was influenced by temperature, dissolved oxygen, and dissolved organic carbon. These findings emphasize the importance of regular monitoring and assessment of trace metals in protected tropical areas and wetlands, helping mitigate environmental risks associated with wastewater discharge and preserving these ecosystems.

Emerging micropollutants in aquatic ecosystems and nanotechnology-based removal alternatives: A review

There is a significant concern about the accessibility of uncontaminated and safe drinking water, a fundamental necessity for human beings. This concern is attributed to the toxic micropollutants from several emission sources, including industrial toxins, agricultural runoff, wastewater discharges, sewer overflows, landfills, algal blooms and microbiota. Emerging micropollutants (EMs) encompass a broad spectrum of compounds, including pharmaceutically active chemicals, personal care products, pesticides, industrial chemicals, steroid hormones, toxic nanomaterials, microplastics, heavy metals, and microorganisms. The pervasive and enduring nature of EMs has resulted in a detrimental impact on global urban water systems. Of late, these contaminants are receiving more attention due to their inherent potential to generate environmental toxicity and adverse health effects on humans and aquatic life. Although little progress has been made in discovering removal methodologies for EMs, a basic categorization procedure is required to identify and restrict the EMs to tackle the problem of these emerging contaminants. The present review paper provides a crude classification of EMs and their associated negative impact on aquatic life. Furthermore, it delves into various nanotechnology-based approaches as effective solutions to address the challenge of removing EMs from water, thereby ensuring potable drinking water. To conclude, this review paper addresses the challenges associated with the commercialization of nanomaterial, such as toxicity, high cost, inadequate government policies, and incompatibility with the present water purification system and recommends crucial directions for further research that should be pursued.

Dynamic nonlinear effects of urbanization on wastewater discharge based on inertial characteristics of wastewater discharge

This study examines the impact of urbanization on wastewater discharge (WD) in 30 provinces in mainland China, considering the inertia characteristics of WD. Various models, including the Tapio decoupling model, dynamic curve relationship model, dynamic threshold effect model, and dynamic quantile model, are employed to analyze the decoupling relationship, curve relationship, threshold relationship, and quantile relationship, respectively. The research findings indicate a shift in the relationship between urbanization and total wastewater discharge (TWD) from expansionary negative decoupling to strong decoupling. Regarding household wastewater discharge (HWD), the relationship is primarily characterized by expansionary negative decoupling and weak decoupling, while industrial wastewater discharge (IWD) is mainly associated with strong decoupling. Urbanization does not exhibit an (inverted) N-shaped relationship with TWD, IWD, and HWD, but it does show an inverted U-shaped relationship with TWD and HWD. The study also reveals that urbanization has a dynamic threshold effect and regional heterogeneity on HWD, but not on TWD and IWD. As the quantile increases, the positive impact of urbanization on TWD and HWD decreases, while the negative impact on IWD increases.

Asymmetric wettable three-dimensional Janus all-cellulose aerogel: Controllable construction with a similar phase self-assembling strategy and oil-water separation performance

Aqueous ecological environment is exacerbated by indiscriminate discharge of industrial and municipal wastewater, particularly oily contaminants. Janus materials with unique asymmetric wettability have been considered potential candidates for oil-water separation. Herein, we developed a novel approach to accomplish controllable construction of three-dimensional Janus all-cellulose aerogel with asymmetric wettability based on a similar phase self-assembling strategy. Significantly, the ratio of asymmetric structures could be controlled by tailoring thickness of hydrophobic/hydrophilic layers. Three-dimensional Janus all-cellulose aerogel had both super-hydrophilic/oleophilic and super-hydrophobic/oleophilic cellulose skeleton structures simultaneously. The adsorption capacity of the aerogel for oil reached up to 34.38 g/g. It could effectively separate a variety of oil-water mixtures and water-in-oil emulsions only driven by gravity, even surfactant-stabilized emulsions. The separation efficiency was more than 99% with the high separation flux. The ‘Trade-off’ effect in the field of membrane separation was avoided effectively. Three-dimensional Janus all-cellulose aerogel exhibited good stability and recyclability. Moreover, the demulsification and separation mechanism was analyzed in details. This work provided not only an environmental-friendly, facile and flexible approach to construct controllable three-dimensional asymmetric wettable Janus materials, but also a scientific understanding and development of the separation mechanism of three-dimensional Janus materials.

Astilbin targeted Sirt1 to inhibit acetylation of Nrf2 to alleviate grass carp hepatocyte apoptosis caused by PCB126-induced mitochondrial kinetic and metabolism dysfunctions

3, 3′, 4, 4′, 5-pentachlorobiphenyl (PCB126) is extensively utilized in electronic products, lubricant, and insecticide due to its excellent chemical stability and insulation prosperity, resulting in its frequent detection in environment. In addition, atmospheric deposition, as well as industrial and urban wastewater discharge can also lead to PCB126 contamination in marine environment, triggering damages to the tissues of aquatic organisms through oxidative stress. Astilbin is a type of flavonoid compound found in plants that plays a crucial role in providing powerful antioxidant and anti-inflammatory properties. In this study, we aimed to investigate the specific mechanism of PCB126-induced damage and the potential protective effect of Astilbin. To achieve this, we treated grass carp hepatocytes (L8824) with 75 μM PCB126 and/or 0.5 mM Astilbin for 24 h and used experimental methods such as Flow cytometry, molecular docking, PPI analysis, detection of commercial kits (ATP concentration and ATPnase activity) and measurement of mitochondrial membrane potential (ΔΨm). Our findings revealed that PCB126 exposure resulted in a decrease in expression levels of Sirt1, factors related to mitochondrial fusion (Opa1, Mfn1, and Mfn2), antioxidant (CAT, SOD1, and SOD2), energy metabolism (PKM2, IDH, and SDH) and anti-apoptosis (Bcl-2), and an increase in expression levels of Nrf2 acetylation, mitochondrial fission (Drp1), factors that promote apoptosis (Cytc, Bax, Cas9, and Cas3) in L8824 cells. Furthermore, our findings revealed a decrease in ΔΨm, ATP concentration and ATPnase activity and apoptosis levels in L8824 cells. Noteworthy, treatment with Astilbin reversed these results. Molecular docking provides solid evidence for the interaction between Astilbin and Sirt1. In summary, our findings suggested that Astilbin promoted the deacetylation of Nrf2 by interacting with Sirt1, thereby alleviating PCB126-induced mitochondrial apoptosis mediated by mitochondrial dynamics imbalance and energy metabolism disorder through the inhibition of oxidative stress in L8824 cells. Our research has initially revealed the correlation between acetylation and apoptosis induced by PCB126, which provided a foundation for a better comprehension of PCB126 toxicity. Additionally, it expanded the potential application value of Astilbin.

Spatial correlation and coupling between industrial enterprise agglomeration and water pollutant discharge

Industrial wastewater discharge has become the main cause of water pollution in China. However, the spatial interaction mechanism between industrial structure and water pollution is still unclear. Accordingly, we evaluated and analyzed spatiotemporal changes of the agglomeration pattern of pollution-intensive industrial enterprises and the evolution of the water environmental pollution pattern, as well as the correlation between them. The study results show that the polluting industrial enterprises were located mainly along the Yangtze River and Taihu Lake Basin in southern Jiangsu in 2013 and 2018. However, we observed a spatial trend of pollution transfer to northern Jiangsu. The industrial water pollution discharge presents the distribution pattern of facing rivers, seas, lakes and cities. Papermaking and paper products industry are the leading factors of COD and NH3–N pollution, with explanatory power of 0.3666 and 0.6201 respectively. The spatial positive coupling effect between the concentration degree of polluting enterprises and the intensity of water environment pollution discharge is 94.95% of the region. The spatial agglomeration of polluting industrial enterprises is an important cause of water environment pollution. They promote and couple each other, proving the existence of “Pollution haven” and “Porter hypothesis".

Remote sensing-based spatiotemporal variation and driving factor assessment of chlorophyll-a concentrations in China’s Pearl River Estuary

Climate change and intensive anthropogenic activities have severely challenged the water quality of China’s Pearl River Estuary (PRE). Further investigations into long-term water quality variation and associated driving mechanisms are therefore necessary to support the sustainable development of the PRE’s Greater Bay Area (GBA). This study used remote sensing retrieval to address long-term spatiotemporal chlorophyll-a (Chl-a) variation characteristics in the PRE and the relationship between Chl-a concentrations and socioeconomic/environmental indicators. Three decades of Landsat satellite images and measured data were collected, and a two-band global algorithm was used to retrieve Chl-a concentration data. Results reveal significant spatiotemporal variability in Chl-a concentrations. The space-averaged Chl-a concentration exhibited a slight downward trend during the past three decades, and the multi-year mean value was 5.20 mg/L. Changes to environmental protection policies in recent years have improved overall PRE water quality. The western section of the PRE had the highest Chl-a concentration (i.e., 5.92 mg/L average) while the eastern section had the lowest (i.e., 3.98 mg/L average). This discrepancy was likely caused by the western section’s more intensive industrial activities, resulting in a higher overall wastewater discharge volume. Affected by climatic conditions, winter Chl-a concentrations were evenly distributed while summer concentrations were significantly higher. Additionally, Chl-a concentrations significantly and positively correlated with total phosphorus (TP), total nitrogen (TN), ammonia nitrogen (NH3-N), and the biotic oxygen demand (BOD5). Chl-a concentrations also correlated with external factors (i.e., climate and anthropogenic activities). Among these factors, industrial wastewater discharge and the proportion of primary industries in coastal cities significantly and positively correlated with water quality. This study is intended to help direct water quality improvement management and urban sustainable development in the GBA.

Anionic polyacrylamide alleviates cadmium inhibition on anaerobic digestion of waste activated sludge

The uncontrolled discharge of industrial wastewater leads to a significant cadmium (Cd) accumulation in waste activated sludge (WAS), posing a serious threat to the steady operation of the anaerobic digestion (AD) system in wastewater treatment plants (WWTPs). Therefore, developing a viable approach to cope with the adverse effects of high-concentration Cd on the AD system is urgently required. This study aims to investigate the potential of using anionic polyacrylamide (APAM), a commonly used agent in WWTPs, to mitigate the adverse effects of Cd in a toxic amount (i.e., 5.0 mg per g total suspended solids (TSS)) on AD of WAS. The results showed that the effectiveness of higher APAM on Cd toxicity alleviation was less than that of lower APAM at the studied level (i.e., the effectiveness order was 1.5 mg APAM per g TSS > 3.0 mg APAM per g TSS > 6.0 mg APAM per g TSS). The moderate supplement of APAM (i.e., 1.5 mg per g TSS) recovered the accumulative methane yield from 190.5 ± 3.6 to 228.9 ± 4.1 mL per g volatile solids by promoting solubilization, hydrolysis, and acidification processes related to methane production. The application of APAM also increased the abundance of key microbes in the AD system, especially Methanolinea among methanogens and Caldilineaceae among hydrolyzers. Furthermore, APAM facilitated the key enzyme activities involved in AD processes and reduced reactive oxygen species (induced by Cd) production via adsorption/enmeshment of Cd by APAM. These findings demonstrate the feasibility of using moderate APAM to mitigate Cd toxicity during AD, providing a promising solution for controlling Cd or other heavy metal toxicity in WWTPs.

Spatio-Temporal Dynamics of Non-Point Source Pollution in Jiulong River Basin (China) Using the Soil & Water Assessment Tool Model in Combination with the GeoSOS-FLUS Model

Water pollution, particularly non-point source pollution, poses a significant environmental challenge in river basins around the world. This complex and dynamic process is influenced by both human activities and natural processes. In this study, a quantitative analysis of ammonia-N and total phosphorus (TP) levels in the North Stream of the Jiulong River basin, China from 2010 to 2018 was conducted using the Soil & Water Assessment Tool (SWAT) model. The model was able to facilitate the simulation of spatio-temporal dynamics of concerned pollutants. Additionally, the GeoSOS-FLUS model was integrated with SWAT to predict land use patterns in 2040 and assess their impact on pollutant dynamics. The results demonstrated that the SWAT model effectively simulated the spatial and temporal dynamics of concerned pollutants in the study area, with satisfactory R2 and NS values for river discharges and pollutant loads. Notably, 2016 exhibited significant pollution levels, particularly in March. The study revealed distinct sources of ammonia-N and TP, originating from aquatic animal breeding areas and industrial wastewater discharge, respectively. Moreover, land use patterns influenced the spatial distribution of pollutants. These findings serve as a crucial data foundation for future endeavors in controlling and mitigating non-point source pollution in the Jiulong River basin.

Durable Co(OH)2/stearic acid-based superhydrophobic/superoleophilic nanocellulose membrane for highly efficient oil/water separation and simultaneous removal of soluble dye

The discharge of industrial oily wastewater is threats to the environment. A long-lasting Co(OH)2/stearic acid (STA)-based superhydrophobic/superoleophilic nanocellulose-based membrane (SSNM) for extremely effective oil/water and simultaneous removal of soluble dye was created to offer solutions to this problem. The mechanical durability of the prepared Co(OH)2/STA-based SSNMs was reinforced by depositing Co(OH)2 and STA on the cellulose fibers. The Co(OH)2/STA-based SSNM shows a high water contact angle of 164 ± 2° and an oil contact angle of ∼0°, exhibiting excellent superhydrophobicity and superoleophilicity. With good usage stability, high separation efficiencies (>94.0%) and high separation fluxes (>130 L·m−2·h−1) were achieved for four oils. The separation flux and efficiency of N-hexane did not change obviously after repeated separation. Furthermore, it exhibited reliable photocatalytic ability, which contributed to the reduction of organic contamination. As a result, Co(OH)2/STA-based SSNM shows strong potential for practical applications such as oil/water separation and photocatalytic degradation of organic pollutants.

Development of ZnO-GO-NiO membrane for removal of lead and cadmium heavy metal ions from wastewater

The presence of heavy metal (HM) ions, such as lead, cadmium, and chromium in industrial wastewater discharge are major contaminants that pose a risk to human health. These HMs should separate from the wastewater to ensure the reuse of the discharged water in the process and mitigate their environmental impacts. The distinctive mechanical properties of 2D graphene oxide (GO), and the antifouling characteristics of metal oxides (ZnO/NiO) nanoparticles combined to produce composites supporting special features for wastewater treatment. This study employed solution casting and phase inversion methods to synthesize PSF-based GO, ZnO-GO, and ZnO-GO-NiO mixed matrix membranes and the effects of variation in composition on the removal of lead (Pb2+) and cadmium (Cd2+) ion was examined. Several characterization techniques including X-ray diffraction analysis, scanning electron microscopy, energy dispersive X-ray, and Fourier transform infrared spectroscopy were applied to analyze the synthesized NPs and MMMs. The composite membranes were also analyzed in terms of their porosity, permeability, hydrophilicity, surface roughness, zeta potential, thermal stability, mechanical strength, and flux regeneration at various transmembrane pressures (2–3 kgcm−2), and pH value (5.5). The highest adsorption capacities were measured to be 308.16 mg g−1 and 354.80 mg g−1 for Pb (II) and Cd (II), respectively, for membrane (M4_A) having 0.3 wt% of ZnO-GO-NiO nanocomposite, at 200 mg L−1 of feed concentration and 1.60 mL min−1 of permeate flux. The Pb (II) and Cd (II) adsorption breakthrough curves were created, and the results of the experiment were compared with the data of the Thomas model.

A novel AI-based approach for modelling the fate, transportation and prediction of chromium in rivers and agricultural crops: A case study in Iran

Chromium (Cr) pollution caused by the discharge of industrial wastewater into rivers poses a significant threat to the environment, aquatic and human life, as well as agricultural crops irrigated by these rivers. This paper employs artificial intelligence (AI) to introduce a new framework for modeling the fate, transport, and estimation of Cr from its point of discharge into the river until it is absorbed by agricultural products. The framework is demonstrated through its application to the case study River, which serves as the primary water resource for tomato production irrigation in Mashhad city, Iran. Measurements of Cr concentration are taken at three different river depths and in tomato leaves from agricultural lands irrigated by the river, allowing for the identification of bioaccumulation effects. By employing boundary conditions and smart algorithms, various aspects of control systems are evaluated. The concentration of Cr in crops exhibits an accumulative trend, reaching up to 1.29 µg/g by the time of harvest. Using data collected from the case study and exploring different scenarios, AI models are developed to estimate the Cr concentration in tomato leaves. The tested AI models include linear regression (LR), neural network (NN) classifier, and NN regressor, yielding goodness-of-fit values (R2) of 0.931, 0.874, and 0.946, respectively. These results indicate that the NN regressor is the most accurate model, followed by the LR, for estimating Cr levels in tomato leaves.

Simulation Analysis of the Dispersion of Typical Marine Pollutants by Fusion of Multiple Processes

The rapid development of coastal economies has aggravated the problem of pollution in the coastal water bodies of various countries. Numerous incidents of massive-scale marine life deaths have been reported because of the excessive discharge of industrial and agricultural wastewater. To investigate the diffusion of typical pollutants after discharge, in this study, a multi-process fusion simulation analysis model of pollutants under the action of ocean currents was established based on the concentration analysis method. Furthermore, key technologies involved, such as the parameter value, data selection, and visualization, were investigated. The iterative analysis and programming realization of three independent sub-processes, such as pollutant diffusion and transport, and the drift path and concentration distribution of pollutants after their discharge into the sea, were visualized. The case study revealed that the increase in the concentration of pollutants in the ocean was affected by the diffusion sub-process, and the transport sub-process plays a critical role in the long-distance transport of pollutants. The proposed method can provide technical support for marine environmental risk assessment and dynamic tracking of marine pollutants.

Biomonitoring of radioactive contamination using benthic invertebrate communities in Manzala Lake, Egypt

Manzala Lake, the largest in Egypt’s Nile Delta, has significant human activity. The Lake’s ecological condition has recently been impacted by a significant increase in agricultural, industrial, and urban wastewater discharge. Avaluable tool for monitoring the water quality of Manzal aLake is the sensitivity of invertebrate species to various types of pollution, such as radioactive contamination. Activity concentrations of radionuclides Radium-226 (226Ra),Thorium-232 (232Th), Potassium-40 ( 40K), and Caesium-137(137Cs) were measured in water, sediments and benthic invertebrate samples in 2020. The benthic community’s spatial distribution and the radionuclides’ bioaccumulation were evaluated to determine possible relationships.Thirty taxa of benthic invertebrates were recognised.The data illustrated that the mean activity concentratio nof radionuclides in water was in the order of 40K > 232Th >226Ra > 137Cs, which changed into 40K > 226Ra > 232Th > 137Csin the sediment and benthic invertebrates. Gastropoda and Ostracoda are the dominating groups of benthos in the lake and are related to the highest concentrations of radionuclides. The benthos species with shells dominated at the sites with the highest activity concentration of 226Ra, while soft-bodied organisms dominated in sites with the highest average 137Cs activity in these samples.

Coal gasification fine slag based multifunctional nanoporous silica microspheres for synergistic adsorption of Pb(II) and Congo red

The discharge of large-scale industrial solid waste and wastewater has caused severe damage to environmental health. In this study, the adsorption behaviors of Pb(II) and Congo Red (CR) dye in single and binary aqueous systems were investigated using novel functionalized nanoporous glass microspheres (NGM). The NGM material was fabricated from coal gasification fine slag (CGFS) by a simple treatment and characterized using TG, BET, XRD, TEM, FT-IR, and XPS to analyze its physicochemical properties. The adsorption experiments showed that the adsorption amounts of DMA-NGM for Pb(II) and CR were 302.39 mg/g and 342.74 mg/g for the single systems, and 372.73 mg/g and 412.93 mg/g for the binary systems, respectively. The increased adsorption capacity was attributed to the synergistic effect of electrostatic attraction and chelation. Furthermore, the pseudo-second-order model and Elovich model could reasonably describe the adsorption of Pb(II) and CR on DMA-NGM. Pb(II) adsorption on DMA-NGM was monolayer adsorption and CR adsorption was multilayer adsorption. In summary, the results demonstrate the potential of efficient and environmentally friendly adsorbents for the resource recovery of CGFS and the processing of printing and dyeing wastewater.

Sustainable wastewater treatment by RO and hybrid organic polyamide membrane nanofiltration system for clean environment

One of the environmental pollution is happened by the discharge of industrial wastewater that needs to be adequately filtered. Given that the effluent from the leather industry contains high levels of chromium, heavy metals, lipids, and Sulphur, it is one of the wastewater disposals that are most damaging. This experimental study focuses on reverse osmosis and hybrid organic polyimide membrane for nanofiltration for sustainable wastewater treatment. In the RO and organic polyamide Nano-porous membranes, a thin film of polyamide membrane was used for efficient filtration. Taguchi analysis optimized process parameters such as pressure, temperature, pH, and volume reduction factor. The outcome shows an 89% reduction in total wastewater hardness, an 88% reduction in sulfate, and an 89% efficiency reduction in COD. As a result, the proposed technology significantly increased filtration efficiency.

Feasibility study of common effluent treatment plant for management of industrial wastewater: Case study of Bangladeshi textile industries

AbstractTextile industries play a vital role in the economy of Bangladesh contributing significantly to its gross domestic product. However, they are associated with high environmental pollution, especially water pollution. Since small‐scale textile industries cannot afford the treatment cost of discharged wastewater, they tend to contaminate water sources—both groundwater and surface water. To intervene in response to this situation, the existing treatment system was assessed in the present study. The effluents from industries under this research were analyzed for color, pH, TSS, TDS, chlorides, sulfates, COD, BOD, and total hardness. A Common Effluent Treatment Plant (CETP) with zero liquid discharge was suggested as a solution. It was observed that the water recovery in the proposed scheme by reverse osmosis and salt recovery using nanofiltration were 90%–95% and 80%–90%, respectively. Cost analysis also indicated that the cost of treating water can also be decreased by 18.7% which can show that water recovery is even more affordable for small‐scale industries. Finally, a linear programming model was developed to assist the industries with decision‐making in the selection of treatment schemes. This research revealed that a CETP using zero liquid discharge technology is a potential solution to the environmental crisis due to industrial wastewater discharge. This could ensure reduced water pollution, increased drinking water availability, improved public health, and thus could be a potential driver for environmental sustainability.