Industrial Wastewater Discharge Research Articles

Effective fabrication and characterization of eco-friendly nano particles composite for adsorption Cd (II) and Cu (II) ions from aqueous solutions using modelling studies

The public health and environment are currently facing significant risks due to the discharge of industrial wastewater, which contains harmful heavy metals and other contaminants. Therefore, there is a pressing need for sustainable and innovative technologies to treat wastewater. The main objective of this research was to develop novel composites known as chitosan, Padina pavonica, Fe(III), and nano MgO incorporated onto pomegranate peel with the specific purpose of removing Cd (II) and Cu (II) ions from aqueous solutions. The characterization of these nanocomposites involved the utilization of several analytical methods, including Fourier-transform infrared spectroscopy, scanning electron microscopy, X-ray diffraction, thermal gravimetric analysis, and X-ray photoelectron spectroscopy. The efficiency of these nanocomposites was evaluated through batch mode experiments, investigating the impact of factors such as pH, initial concentration, contact time, and adsorbent dose on the adsorption of Cu(II) ions. The optimum conditions for the removal of ions were pH = 5 for Cu (II) and 6 for Cd (II), contact time: 120 min, adsorbent dosage: 0.2 g, initial metal ion concentration: 50 mg/L for each metal ion for the present study. The MgO@Pp demonstrated the highest removal efficiencies for Cu(II) and Cd(II) at 98.2% and 96.4%, respectively. In contrast, the CS@Fe-PA achieved removal efficiencies of 97.2% for Cu(II) and 89.2% for Cd(II). The modified MgO@Pp exhibited significantly higher total adsorption capacities for Cu(II) and Cd(II) at 333.3 and 200 mg/g, respectively, compared to CS@Fe-PA, which had capacities of 250 and 142 mg/g, respectively. The adsorption of Cd (II) and Cu (II) ions by MgO@Pp was found to be a spontaneous process. The R2 values obtained using the Freundlich and Redlich-Peterson models were the highest for the MgO@Pp composite, with values of 0.99, 0.988, 0.987, and 0.994, respectively, for Cu (II) and Cd (II). The pseudo-second-order equation was determined to be the best-fit kinetic model for this process. Reusability experiments confirmed that the adsorbents can be utilized for up to four regeneration cycles. Based on the findings of this study, MgO @ Pp is the most promising alternative and could be instrumental in developing strategies to address existing environmental pollution through adsorption.

Green Fabrication of Superhydrophilic/Underwater Superoleophobic Composite Membrane for High-Efficiency Oil/Water Separation in Harsh Environments.

Due to the high oil spill incidence and industrial wastewater discharge including oil and emulsified oil, designing and synthesizing oil-water separation materials which can maintain stability under harsh environmental conditions with high separation efficiencies remains a great challenge. The present work developed an easy, green, cost-effective, and easily scaled-up approach for fabricating cellulose-based membranes. First, we coated polydopamine (PDA) onto fibers of filter membrane (FM). Then, the PDA-FM membrane was immersed into the mixed solution of poly(vinyl alcohol)/poly(acrylic acid) (PVA/PAA) and further thermally cross-linked at 150 °C to create a superhydrophilic/underwater superoleophobic membrane (PVA/PAA@PDA-FM) to separate oil/water mixtures. The simple thermally cross-linking process promotes multiple covalent chemical bonds generation between cellulose filter membrane, PAA, PDA, and PVA, endowing membranes with excellent stability and resistance to acidity, alkalinity, and salinity. The PVA/PAA@PDA-FM membrane not only demonstrates great separation performance (>99.8%) and great flux (>1000 L m-2 h-1) in oil-water immiscible mixtures but also maintains high separation efficiency under conditions of high acidity, alkalinity, and salinity. Additionally, the PVA/PAA@PDA-FM membrane exhibits excellent separation capacity in oil-water emulsions, which can maintain the >99.6% separation efficiency even after 40 cycles in harsh environments, showing outstanding reusability. Thus, due to the multiple cross-linked networks in the membrane, the excellent performance makes the PVA/PAA@PDA-FM membrane a good application prospect in water purification and oily wastewater treatment.

Synthesis, characterisation and application of organic and inorganic bentonite for the removal of gentian violet

ABSTRACT The intensive use of dyes in industry has caused serious pollution problems, due to industrial wastewater discharges. It is well known that dyes have harmful effects on humans, animals, and other living beings. Therefore, the treatment of industrial wastewater before its release into the environment requires great attention. This work is devoted to the study of the effect of organic modifications by DMSO and/or CTAB and an inorganic modification by spinel oxide ZnCr2O4 on the structural and textural properties of local clay (M’Zila bentonite). The materials resulting from these modifications are used as adsorbents for a cationic dye such as gentian violet. These materials were synthesised and characterised by XRD, FTIR, BET and SEM. These analyzes confirmed the considerable changes in the structure of the clays modified by DMSO and/or CTAB- ZnCr2O4, the formation of pillared bentonites and the increase in the basal spacing’s of the modified clays by 15.05 Å for the bentonite of M’Zila at 23.80 Å for bentonite-CTAB-ZnCr2O4 (BCZnCr), at 27.37 Å for bentonite-DMSO-ZnCr2O4 (BDZnCr) and at 25.89 Å for bentonite-DMSO-CTAB-ZnCr2O4 (BDCZnCr).These modifications produced a rougher and more porous surface, resulting in a significant increase in the specific surface area from 60.13 m2 g−1 for sodium bentonite to 104.63 m2 g−1 for BCZnCr and 104.59 m2 g−1 for BDCZnCr. The adsorption of gentian violet was carried out under the following conditions: solid liquid ratio: 1 g/L, pH = 10 and contact time at equilibrium 1 h. The adsorption kinetics perfectly follows the pseudo second order model as well as that of intraparticle diffusion for all materials. The isotherms are of type S; they are well described by the Langmuir-Freundlich model. The thermodynamic parameters indicate that the physisorption of gentian violet by the different materials is spontaneous, exothermic, and disordered.

Superhydrophobic/ superoleophilic polystyrene-based porous material with superelasticity for highly efficient and continuous oil/water separation in harsh environments

Three-dimensional separation materials with robust physical/chemical stability have great demand for effective and continuous separation of immiscible oil/water mixtures and water-in-oil emulsions, resulting from chemical leakages and discharge of industrial oily wastewaters. Herein, a superelastic polystyrene-based porous material with superhydrophobicity/superoleophilicity was designed and prepared by high internal phase emulsion polymerization to meet the aforementioned requirements. A flexible and hydrophobic aminopropyl terminated polydimethylsiloxane (NH2-PDMS-NH2) segment was introduced into the rigid styrene-divinylbenzene copolymer through 1, 4-conjugate addition reaction with trimethylolpropane triacrylate. The addition of NH2-PDMS-NH2 simultaneously improved the mechanical and hydrophobic properties of the porous material (the water contact angle from 141.2° to 152.2°). The material exhibited outstanding reversible compressibility (80% strain, even in liquid N2 environments) and superhydrophobic stability, even after being repeatedly compressed 100 times, water contact angle still remained above 150°. Meanwhile, the as-prepared material had outstanding hydrophobic stability in corrosive solutions (strong acidic, alkaline, high-salty, and even strong polar solvent), presence of mechanical interference, strong UV radiations, and high/low temperature environments. More importantly, the material could continuously and efficiently separate immiscible oil/water mixture and water-in-oil emulsions under the above conditions, showing huge potential for the large-scale remediation of complex oily wastewaters.

Assessing teratogenic risks of gadolinium in freshwater environments: Implications for environmental health

Gadolinium (Gd) is among the rare earth elements extensively utilized in both industrial and medical applications. The latter application appears to contribute to the rise in Gd levels in aquatic ecosystems, as it is excreted via urine from patients undergoing MRI scans and often not captured by wastewater treatment systems. The potential environmental and biological hazards posed by gadolinium exposure are still under investigation. This study aimed to assess the teratogenic risk posed by a gadolinium chelate on the freshwater cnidarian Hydra vulgaris. The experimental design evaluated the impact of pure Gadodiamide (25 μg/l, 50 μg/l, 100 μg/l, 500 μg/l) and its commercial counterpart compound (Omniscan®; 100 μg/l, 500 μg/l, 782.7 mg/l) at varying concentrations using the Teratogenic Risk Index (TRI). Here we showed a moderate risk (Class III of TRI) following exposure to both tested formulations at concentrations ≥ 100 μg/l. Given the potential for similar concentrations in aquatic environments, particularly near wastewater discharge points, a teratogenic risk assessment using the Hydra regeneration assay was conducted on environmental samples collected from three rivers (Tiber, Almone, and Sacco) in Central Italy. Additionally, chemical analysis of field samples was performed using ICP-MS. Analysis of freshwater samples revealed low Gd concentrations (≤ 0.1 μg/l), despite localized increases near domestic and/or industrial wastewater discharge sites. Although teratogenic risk in environmental samples ranged from high (Class IV of TRI) to negligible (Class I of TRI), the low Gd concentrations, particularly when compared to higher levels of other contaminants like arsenic and heavy metals, preclude establishing a direct cause-effect relationship between Gd and observed teratogenic risks in environmental samples. Nevertheless, the teratogenic risks observed in laboratory tests warrant further investigation.

Hollow hydroxyapatite constructs dual channel structured separation membranes for ultra-fast oil-water separation

The discharge of industrial wastewater and frequent oil spills have caused serious harm to the environment, and in order to achieve sustainable development of the environment, membrane separation technology stands out among the many methods for treating oil and water. In this work, hollow hydroxyapatite was grown in situ on Mg Al LDH to construct an oil–water separation membrane with dual channels, and water molecules could not only pass through the porous structure of HAP, but also pass through the gap between HAP and LDH, and the opening of the dual channels greatly improved the oil–water separation speed, and the flux of the petroleum ether emulsion was up to 5208.93 ± 117.62 L/(m2·h·bar) with the separation efficiency up to 99.4 %, and still has 98.8 % rejection rate after 10 cycles, it can efficiently separate many kinds of heavy metal ions and dyes. In order to evaluate the practical performance of the membrane, we found a high rejection rate of 87 % after several cycles of the shale gas fracking wastewater, and this work provides a new idea for the development of oil–water separation membranes with practical applications.

Distinguishing the contributions of different smelting emissions to the spatial risk footprints of toxic elements in soil using PMF, Bayesian isotope mixing models, and distance-based regression

Toxic element pollution of soils emanating from smelting operations is an escalating global concern due to its severe impact on ecosystems and human health. In this study, soil samples were collected and analyzed to quantify the risk contributions and delineate the spatial risk footprints from smelting emissions for 8 toxic elements. A comprehensive health risk contribution and delineation framework was utilized, consisting of Positive matrix factorization (PMF), spatial interpolation, an advanced Bayesian isotope mixing model via Mixing Stable Isotope Analysis in R (MixSIAR), and distance-based regression. The results showed that the mean concentrations of As, Cd, Cu, Hg, Pb, and Zn exceeded the background levels, indicating substantial contamination. Three sources were identified using the PMF model and confirmed by spatial interpolation and MixSIAR, with contributions ranked as follows: industrial wastewater discharge and slag runoff from the smelter site (48.9 %) > natural geogenic inputs from soil parent materials (26.7 %) > atmospheric deposition of dust particles from smelting operations (24.5 %). Among the identified sources, smelter runoff posed the most significant risk, accounting for 97.9 % of the non-carcinogenic risk (NCR) and 59.9 % of the carcinogenic risk (CR). Runoff also drove NCR and CR exceedances at 7.8 % and 4.7 % of sites near the smelter, respectively. However, atmospheric deposition from smelting emissions affected soils across a larger 0.8 km radius. Although it posed lower risks, contributing just 1.1 % to NCR and 22.6 % to CR due to the limited elevation of toxic elements, deposition reached more distant soils. Spatial interpolation and distance-based regression delineated high NCR and CR exposure hotspots within 1.4 km for runoff and 0.8 km for deposition, with exponentially diminishing risks at further distances. These findings highlight the need for pathway-specific interventions that prioritize localized wastewater containment and drainage controls near the smelter while implementing broader regional air pollution mitigation measures.

Analysis on the spatiotemporal evolutions of groundwater hydrochemistry and water quality caused by over-extraction and seawater intrusion in eastern coastal China

The over-extraction of groundwater has resulted in seawater intrusion and the southward migration of the saltwater interface, gradually deteriorating the groundwater quality in the Weibei Plain. In this research, groundwater samples were gathered from 46 monitoring wells for shallow groundwater during the years 2006, 2011, 2016, and 2021. The hydrochemical features of regional groundwater and the factors influencing the issue were subjected to statistical analysis. Additionally, the assessment of spatiotemporal variations in groundwater quality was conducted using the customized entropy-weighted water quality index (EWQI) method. The relationship between groundwater over-extraction and the southward intrusion of the saltwater interface was compared and analyzed. The results of this paper revealed that the Weibei Plain has been in a state of long-term over-extraction of groundwater from 2000 to 2021, with an average annual over-extraction of 118.49 million m3. The groundwater depression cone areas in the northern part of the study area increased from 3,247.37 to 4,581.34 km2 from 2006 to 2021, with the center of the cone experiencing a drop in groundwater level from −22 to −85 m. The saltwater interface shifted southward by 711.71 km2 from 2006 to 2021. In groundwater, the high concentrations of TH, TDS, and Cl− were primarily related to the seawater intrusion, while higher concentrations of NO3− were mainly determined by frequent agricultural production, industrial wastewater, and domestic sewage discharges. The groundwater hydrochemical types in the study area transitioned from predominantly HCO3·Ca-Mg type in 2006 to HCO3-Na type and SO4·Cl-Ca·Mg type in 2021 due to seawater intrusion. The results of PCA and HCA show the effects of seawater intrusion, human activities, and rock weathering on groundwater hydrochemistry. The evaluation results based on the EWQI revealed that the average value of the samples in 2021 was 101.36, which belonged to Class IV water quality standards, representing the poorest water quality among the 4 years. The southward migration of the saltwater interface led to the deterioration of groundwater quality in the groundwater depression cone areas, which gradually worsened from 2006 to 2021. The maximum increase in EWQI value was 174.68 during the period, shifting from Class III water quality to Class V water quality. Groundwater quality remained relatively better in the western and southern regions which were less affected or unaffected by seawater intrusion. The results of the study can provide a certain reference value for the sustainable management of groundwater resources and the management of groundwater pollution and seawater intrusion in the Weifang City area in the future.

Empirical analysis of the relationship between economic growth and environmental pollution based on VAR model: A case study of Hubei Province China

In this paper, the industrial three wastes from 1992 to 2018 in Hubei Province were collected as environmental indicators, and the per capita GDP was used as economic indicators. The study of Kuznets curve showed that industrial wastewater gradually decreased with economic growth, showing an inverted N shape; Both industrial emissions and solid waste will increase with the growth of per capita GDP, industrial waste gas shows a linear relationship, and industrial solids show an inverted U relationship. Then through the VAR model research, it is found that the response of industrial “three wastes” to per capita GDP growth in Hubei Province is positive in the short term. The long-term response of economic development in Hubei province to industrial waste gas and industrial solid waste discharge is positive and decreasing, but the short-term response to industrial wastewater discharge is negative. The variance decomposition analysis reveals that the primary environmental determinants influencing the current economic growth trajectory of Hubei Province are industrial wastewater, industrial waste gas, and industrial solid waste. Fluctuations in economic growth within Hubei Province demonstrate a stronger correlation with variations in emissions of industrial wastewater and industrial solid waste, while exerting comparatively less influence on changes in emissions of industrial waste gas.

N-nitrosamines in electroplating and printing/dyeing industrial wastewater treatment plants: Removal efficiency, environmental emission, and the influence on drinking water

The discharge of industrial wastewater containing high concentrations of N-nitrosamines to the aquatic environment can impair downstream source waters and pose potential risks to human health. However, the transport and fate of N-nitrosamines in typical industrial wastewater treatment plants (IWWTPs) and the influence of these effluents on source water and drinking water are still unclear. This study investigated nine N-nitrosamines in four full-scale electroplating (E-) and printing/dyeing (PD-) IWWTPs, two drinking water treatment plants (DWTPs) in the lower reaches of these IWWTPs, and the corresponding tap water in South China. The total concentrations of N-nitrosamines (∑NAs) were 382–10,600, 480–1920, 494–789, and 27.9–427 ng/L in influents, effluents, source water, and tap water, respectively. The compositions of N-nitrosamine species in different influents varied a lot, while N-nitrosodi-n-butylamine (NDBA) and N-nitrosodimethylamine (NDMA) dominated in most of the effluents, source water, and tap water. More than 70 % N-nitrosamines were removed by wastewater treatment processes used in E-IWWTPs such as ferric-carbon micro-electrolysis (Fe/C-ME), while only about 50 % of N-nitrosamines were removed in PD-IWWTPs due to the use of chlorine reagent or other inefficient conventional processes such as flocculation by cationic amine-based polymers or bio-contact oxidation. Therefore, the mass fluxes of N-nitrosamines discharged from these industrial wastewaters to the environment in the selected two industrial towns were up to 14,700 mg/day. The results based on correlation and principal component analysis significantly demonstrated correlations between E-and PD-effluents and source water and tap water, suggesting that these effluents can serve as sources of N-nitrosamines to local drinking water systems. This study suggests that N-nitrosamines are prevalent in typical IWWTPs, which may infect drinking water systems. The findings of this study provide a basis data for the scientific evaluation of environmental processes of N-nitrosamines.

Functional diversity and secondary production of macrofaunal assemblages can provide insights of biodiversity-ecosystem function relationships

BackgroundSemi-enclosed bays are important links in the material cycle and energy flow between terrestrial and marine ecosystems. They are also areas of intense human activities and heavily influenced by such activities as aquaculture, industrial and agricultural wastewater discharge. The rate of biodiversity loss and changes in ecosystems have prompted research into the relationship between species diversity and ecosystem functioning. Studies have shown that application of functional diversity indices is useful for assessing the status of ecosystem functioning. We quantitatively sampled macrofauna in a semi-enclosed bay in four seasons and analyzed the relationship between species, functional diversity and secondary production, biomass and feeding functional groups of macrofauna.ResultsThe annual secondary production was 325.01 kJ m−2 year−1. Detritivorous, carnivorous and planktophagous feeders were the main functional groups of macrofauna. Differences in the spatial–temporal distribution of functional groups were influenced by Ruditapes philippinarum and Hemileucon bidentatus. Functional richness had significant negative correlations with macrofaunal biomass and secondary production. Functional divergence, functional dispersion and Rao's quadratic entropy had highly significant negative correlations with macrofaunal biomass and secondary production.ConclusionThe results showed that high overlap of ecological niches can increase competition for habitat resources, leading to a decline in biomass and secondary production. In addition, aquaculture could promote the use of habitat resources to some extent, while it could increase competition for ecosystem resources (including habitat resources, atmospheric resources, water resources, etc.). Functional diversity is a good indicator for the ecosystem functioning and the competition status for habitat resources, which can provide insights into the current state of ecosystem function.

Development of an efficient, low-operating-pressure graphene oxide/polyethersulfone nanofiltration membrane for removing various water contaminants

Conventional wastewater treatment technologies tend to be high-capex, energy-intensive solutions that lack specificity for different pollution classes, and do not lend themselves to wide-scale deployment, particularly in areas of the world where industrial wastewater discharge is a significant environmental problem. In tandem, solid waste pollution arising, particularly plastic containing waste, is a persistent and serious pollution issue. This work focuses on the concept of "waste treating waste" and a multidisciplinary effort ranging from materials science and environmental management to sustainable water treatment, in addition to production of graphene oxide from mineral water waste bottles using a simple synthetic procedure that can be economically scaled up for use as a cost-effective adsorbent. Prepared graphene oxide was supported on a polyethersulfone (PES) membrane, and batch filtration studies were performed to examine its performance in the removal of methylene blue (MB) dye, Gentimicin sulphate (GMS) antibiotic, and Na2SO4 and MgSO4 salts from an aqueous solution. Operating parameters such as initial pollutant concentration, time, and solution pH were investigated and optimized using a response surface methodology (RSM) model. The results confirm the significant efficiency of the filtration process, with a maximum rejection of about 91% for MB, 93% for GMS, 67% for Na2SO4, and 64% for MgSO4, with maximum water flux of 1322, 1367, 1225, and 1059 LMH, respectively. Density functional theory calculations were considered for the GO, PES membrane, and GO/PES membrane with a GGA/PBE optimization level. Adsorption annealing locator analysis was performed for the GO/PES membrane, and the process was recalculated for MB as adsorbate. In conclusion, the adsorption effect employing produced GO/PES membrane is the most important removal, followed by Donnan exclusion and steric hindrance effect. Therefore, it is possible to build new eco-friendly membranes for nanofiltration that are affordable, stable, and effective in removing various pollutants from water systems.

THE ROLE OF ENVIRONMENTAL REGULATION, HETEROGENEOUS TECHNOLOGICAL PROGRESS ON MUNICIPAL INDUSTRIAL WASTEWATER DISCHARGES: EVIDENCE FROM YANGTZE RIVER ECONOMIC BELT IN CHINA

The large amount of industrial wastewater discharges has significantly limited the sustainable development of China’s resources and posed hazards to human health. In order to contain industrial wastewater discharges, the government has formulated a series of environmental control policies, but the effectiveness of these policies remains a controversial issue. With the rapid development of science and technology, how likely can China rely on technological progress to achieve a win-win outcome for both economic growth and environmental protection? This paper uses data from 105 cities in the Yangtze River Economic Belt over the period 2005–2020 to investigate the effects of environmental regulation and heterogeneous technological progress on industrial wastewater discharges. The results show that environmental regulation and technology introduction effectively reduce industrial wastewater discharges, and independent innovation aggravates industrial wastewater pollution. The interaction analysis reveals that under the influence of environmental regulation, independent innovation will significantly alleviate industrial wastewater discharges in the Yangtze River Economic Belt. In addition, this study also reveals spatial and temporal heterogeneity in the effects of environmental regulations and different types of technological advances on industrial wastewater discharges.

Evaluating Groundwater Quality Using Multivariate Statistical Analysis and Groundwater Quality Index

Under pressure from surface water pollution and climate change, groundwater becomes a critical water source. Information on groundwater quality could contribute to effective groundwater management. This study was carried out to utilize multivariate statistical analysis and the groundwater quality index (GWQI) to evaluate groundwater quality in Ca Mau Province, Vietnam. Twenty-five groundwater samples from residential-urban areas, cemetery areas, landfill areas, and saline intrusion areas were collected for this study. Groundwater quality was evaluated using the National Technical Regulation on Groundwater Quality (QCVN 09-MT:2015/BTNMT) and GWQI. Principal component analysis (PCA) was used to identify potential polluting sources and key variables influencing groundwater quality. Cluster analysis (CA) was applied to cluster groundwater quality, and the sites were recommended for future monitoring. The results revealed that NH4+-N contaminated groundwater in the landfill area, while the saline intrusion area was polluted by TDS and NH4+-N. The groundwater quality classified as excellent, good, poor, and very poor accounted for 44, 40%, 12%, and 4%, respectively. Cluster analysis divided groundwater quality into four groups, mainly based on the presence of NH4+-N and TDS. Nine groundwater sampling locations could be removed from the current groundwater quality program but still ensuring representativeness as a result of CA. PCA proposed two main sources of variation in groundwater quality at each residential-urban area: the cemetery area, the landfilling area, and the saline intrusion area. The groundwater parameters (i.e., pH, TDS, permanganate index, NH4+-N, NO3--N, and Fe) should be continued to monitor. Domestic and industrial wastewater discharge, leachate from cemeteries and landfills, the nature of groundwater aquifers, and seawater intrusion could be potential sources of groundwater variation. The current findings provide scientific information for local environmental authorities to manage and monitor groundwater quality in the study area. Doi: 10.28991/CEJ-2024-010-03-03 Full Text: PDF

A study on the economic loss estimation of industrial wastewater pollution discharges in the Yangtze River Delta urban agglomeration

ABSTRACT This study focuses on the industrial wastewater discharge of 27 cities in the Yangtze River Delta urban agglomeration. It selects five water pollutant indicators from industrial wastewater discharge, including chemical oxygen demand (COD), total nitrogen (TN), total phosphorus (TP), petroleum pollutants (PP), and major heavy metal content (HM). A shadow price model for industrial wastewater discharge pollutants in each city of the Yangtze River Delta urban agglomeration is constructed, and empirical research is conducted using government-provided statistical data. The study reveals that the economic losses associated with industrial wastewater discharge in the 27 cities of the Yangtze River Delta urban agglomeration range from 5.9296 billion to 6.448 billion yuan. Shanghai demonstrates the highest economic losses caused by industrial wastewater discharge, surpassing 0.45 billion yuan annually. In contrast, Anqing city experiences the lowest economic losses, approximately ranging from 93 million to 104 million yuan per year due to industrial wastewater discharge.

Potentially harmful elements and health risk assessment in groundwater of urban industrial areas

Groundwater quality was investigated in three urban semi-arid multi-industrial metropolitan areas i.e. (Hayatabad Industrial Estate, Peshawar (HIEP), Gadoon Industrial Estate, Swabi (GIES) and Hattar Industrial Estate, Haripur (HIEH). The main aim of the study was to determine their physicochemical parameters, potentially harmful elements (PHEs) concentration, pollution sources and public health risks in semi-arid multi-industrial metropolitan areas of Khyber Pakhtunkhwa (KPK), Pakistan. The physicochemical parameters (pH, TDS and EC), PHEs (Cd, Zn, Pb, Cr and Ni) concentrations and Mg in drinking water sources were found within the permissible limits, except Fe, which exceeded the World Health Organization (WHO) acceptable limit. Among PHEs, Zn had the highest contribution rates of 69.6%, 58.2% and 67.64% in HIEP, GIES and HIEH, respectively, while Cd showed the lowest contribution rates (3.15%, 1.98% and 2.06%) for HIEP, GIES and HIEH respectively. Principal component analysis (PCA) showed significant correlations between parameters, with contributions of industrial effluents and wastewater discharge (46.81%), mixed sources (34.05%) and geo-genic sources (19.14%) for drinking water in the study area. The carcinogenic risk (CR) for Cd, Cr, Ni and Pb, were found within the acceptable threshold value of 1 × 10−4. This study suggests that urban groundwater should also be regularly monitored for PHEs contamination as over-extraction, industrialization and informal E-waste recycling events surges the public health risks globally, facing related environmental contamination difficulties of the urban groundwater.

Ecology versus economic development: Effects of China's Yangtze River Economic Belt strategy

AbstractThis study employs China's Yangtze River Economic Belt strategy as a quasi‐natural experiment to investigate the impact of prioritizing green development on economic growth. Our empirical findings show that the strategy significantly reduces urban industrial wastewater discharge. It helps transition the region's industries towards technology‐driven service sectors while maintaining a steady economic growth rate. On average, cities in the Yangtze River Economic Belt see a 21.9% decrease in annual industrial wastewater discharge, a 1.9% increase in economic growth rate, a 4.9% rise in the proportion of service industries' contribution to GDP, and a 2.4% increase in the number of employees in productive service industries. Moreover, our empirical results highlight the heterogeneity in the effects of the strategy across different regions, which can be attributed to factors such as population density, infrastructure, levels of human capital, and government governance. The implementation of the Yangtze River Economic Belt strategy offers valuable insights for developing countries on how to balance between economic development and environmental protection.

3D hierarchical aquaporin-like nanoporous graphene membrane with engineered tripartite nanochannels for efficient oil/water separation

The aqueous system is being polluted by the untreated direct discharge of industrial oily wastewater into the ecosystem. Due to its low cost, energy economy, and sustainability, the advanced membrane filtration method is regarded as one of the best methods for treating oily wastewater. Its exceptional atomic thickness and superior amphiphilic properties of graphene oxide (GO) nanosheet make it one of the finest 2D constituents for creating membranes with high permeability. Nevertheless, the interlayer d-spacing of multi-stacked GO membranes is crucial since it is responsible for the permeability/selectivity trade-off. To efficiently separate oil-in-water emulsion using an in-situ polymerization technique, we developed an aquaporin-like 3D hierarchical multi-functionalized nanoporous graphene (NPG) membrane with tripartite nanochannels. The extraordinary, prepared membrane displayed both ultra-water-permeability of 2490 L m−2 h−1.bar along with superior selectivity. Consequently, the permeance of the aquaporin-like 3D hierarchical multi-functionalized NPG membrane achieves a higher flux than the GO membrane, while the oil rejection reaches ~97%.

Nitrogen and sulfur-doped biochar supported magnetic CuZnFe2O4 as a sustainable adsorbent for efficient reactive black dye 5 removal from industrial wastewater

AbstractThe shortage of clean and safe water resources, due to the growing pollution and the high cost of water treatment techniques, has become a real threat. Herein, CuZnFe2O4@N,S-doped biochar (CZF@N,S-BC), a novel magnetic, cleaner, and completely green-based composite, was fabricated using the aqueous extract of Beta vulgaris (sugar beet) leaves for the efficient removal of reactive black dye 5 (RB5) from industrial wastewater discharge. With the aid of numerous techniques, including Fourier-Transform Infrared Spectroscopy (FTIR), X-ray Photoelectron Spectroscopy (XPS), Scanning Electron Spectroscopy (SEM), Vibrating Sample Magnetometer (VSM), and zeta potential analyses, CZF@N,S-BC was well-characterized. The results revealed the successful fabrication of CZF@N,S-BC with good magnetic saturation of 12 emu/g and a highly positively charged surface of 32 mV at pH 2. The removal efficiency of RB5 was reached 96.5% at equilibrium time 60 min, and adsorbent dose of 80 mg. The equilibrium data fitted well with the Freundlich isotherm model, while the adsorption kinetics followed a pseudo-second-order model (PSO), with a maximum adsorption capacity of 276.57 mg/g. The thermodynamics results confirmed the physical interaction between the composite and RB5. Additionally, the composite also demonstrated exceptional reusability, maintaining a removal efficiency of 57.27% even after six consecutive cycles. To evaluate the performance of CZF@N,S-BC composite in a real water matrix, the composite was subjected to remove RB5 from a real wastewater sample obtained from an industrial discharge of a textile dyeing industry. Also, a plausible mechanism of RB5 removal by the composite was intensively discussed using XPS before and after adsorption.

Yin-Yang membrane with dual superwettabilities for controllable separation of complex oil/water mixtures

Oil spill incidents and massive discharge of oily industrial wastewater have a profound negative impact on the global water ecosystem. Super-wettable membranes have emerged as a promising solution for oil/water separation. However, challenges arise when this technique is applied to different kinds of oily wastewater, especially triphase heavy oil/light oil/water mixtures, because of the membranes’ single function and limited applicability. Drawing inspiration from the Taiji diagram, we proposed a novel ‘Yin-Yang’ membrane (YYM) with dual superwettabilities to address these challenges. The unique dual superwettabilities make it possible to precisely independently adjust the wetting film and the corresponding liquid permeability at the Yin and Yang regions through the controllable pre-wetting. The YYM could achieve continuous separation with a high efficiency (over 99.1 %) and a large total flux (over 54.4 × 103 L·m−2·h−1) for triphase oil/water mixtures, regardless of liquid species and densities. Proof-of-concept experiments highlight the noticeable biocompatibility of YYM-filtrated water from hypertoxic oily wastewater. The YYMs enlighten the design of new super-wettable materials for use in hazardous waste elimination and water ecological restoration.