Agricultural Wastewater Research Articles

Treatment and Valorization of Slaughterhouse Wastewater in Agriculture

Treatment and Valorization of Slaughterhouse Wastewater in Agriculture

Irrigation suitability assessment of urban wastewater for sustainable agriculture: a case study of Musi river, India

In urban areas with dense populations and high water demands, effective management of water resources is crucial for sustainable development. It includes optimizing water usage and recycling wastewater to balance supply and demand. Urban rivers, which now carry sewage year-round due to increased urban water consumption, are increasingly used for irrigation in peri-urban regions. This study aims to assess the suitability of an urban stream for irrigation compared to catchment groundwater, using hydrochemical parameters to evaluate water quality indices. Analysis of major ion distribution from upstream to downstream reveals a significant increase of TDS (r2 = 0.65; p < 0.001) in the surface water and a decrease (r2 = 0.93; p < 0.001) in groundwater samples. The calculated Weighted Arithmetic-Water Quality Index (WA-WQI) indicates that around 85% and 75% of surface water and groundwater samples from the Musi river are classified as very poor to unsuitable for any use, highlighting critical pollution levels. Based on irrigation suitability indices, only 16% of the surface water samples and 60% of the groundwater samples are suitable for irrigation. The nitrate concentration increased from less than 10 mg l−1 in the upstream region to over 100 mg l−1 in the urban stretch. Nitrogen-Phosphate-Potassium (NPK) ratios across the basin are exceptionally higher, representing crops irrigated using the Musi river water might not require fertilizer applications. The adoption of fertilizer application concerning supplied water hydrochemistry, particularly the NPK ratio, might limit the excess usage of fertilizer and benefit farmers. Additionally, this practice may also limits the excess input of nitrate to the groundwater in the Musi river basin.

Comparison of Biohydrogen Production by Tetraselmis subcordiformis During Cultivation Using Soil-Less Agricultural Wastewater and Effluent from Microbial Fuel Cells

The development and implementation of innovative production technologies have a direct influence on the creation of new sources of pollution and types of waste. An example of this is the wastewater from soil-less agriculture and the effluent from microbial fuel cells. An important topic is the development and application of methods for their neutralisation that take into account the assumptions of global environmental policy. The aim of the present study was to determine the possibilities of utilising this type of pollution in the process of autotrophic cultivation of the biohydrogen-producing microalgae Tetraselmis subcordiformis. The highest biomass concentration of 3030 ± 183 mgVS/L and 67.9 ± 3.5 mg chl-a/L was observed when the culture medium was wastewater from soil-less agriculture. The growth rate in the logarithmic growth phase was 270 ± 16 mgVS/L-day and 5.95 ± 0.24 mg chl-a/L-day. In the same scenario, the highest total H2 production of 161 ± 8 mL was also achieved, with an observed H2 production rate of 4.67 ± 0.23 mL/h. Significantly lower effects in terms of biomass production of T. subcordiformis and H2 yield were observed when fermented dairy wastewater from the anode chamber of the microbial fuel cell was added to the culture medium.

Boronate affinity metal–organic frameworks molecularly imprinted membranes with hierarchical porous channels for the selective separation of naringin

Naringin (NRG), known as an important natural flavoniod compounds, exhibits excellent phamaceutical value and clinical application prospect. However, the main obstacle to the isolation and purification of NRG is the low concentration and complexity of the extraction system. Herein, a new kind of hierarchical porous metal–organic frameworks (MOFs) based molecularly imprinted membranes (PBMMA-MIMs) for the specific separation of NRG. The prepared PBMMA-MIMs showed the fast adsorption kinetics (within 120 min). Moreover, the abundant boronic acid imprinted recognition sits and hydrophilic hierarchical porous MOFs improved the adsorption capacity (the maximum adsorption amounts 57.39 μmol/g) and exhibited selective NRG adsorption (imprinting factor 2.31) with efficiency over 91.69 % after seven adsorption–desorption cycles. In addition, the coarse NRG could be effectively extracted to a promising purity of 93.13 % via PBMMA-MIMs. This study provides new insights into the design molecularly imprinted membranes via environmentally friendly synthesis route for the preparation for enriching high-value flavoniods, achieving efficient purification rate of agricultural wastes for pollution control, and promoting the sustainable reuse in complex agricultural wastewater.

Quality Determination of Dairy Farm Wastewater in Dinajpur

At present environmental pollution is a talked about issue. Due to environmental pollution, humans and animals face threats. The scientist has pointed out that waste is one reason for climate change. Solid, liquid, gaseous etc. are different types of waste. The experiments were conducted to determine the chemical constituents present in dairy farm wastewater, wastewater management practice and environmental impact and compare it with the groundwater Dinajpur Sadar upazila. The data concerning the dairy farm wastewater in Dinajpur was obtained through a designed questionnaire, and separate area inspection interacting with the proprietor and workers in the dairy farm. Randomly collected samples from different dairy farms. The chemical constituents of the wastewater sample were determined by a laboratory experiment. The wastewater contained Mg, Na, Ca, Cl-, K, EC, P, HCO3-, pH, TDS, DO, COD, Zn, S, BOD, HT and NO3-. The Na, K, Ca and pH concentration of wastewater under the range in groundwater in Dinajpur. However, concentrations of P, TDS, Mg, EC, Cl-, HCO3- and HT are above the groundwater range in Dinajpur. The produced wastewater was disposed of either through drainage or piping systems on fellow land, ponds, open lakes, roadside land, urban drains, and rivers. The unplanned wastewater disposal creates bad odor, and environmental pollution, seduces the growth of mosquitoes decreases the water quality, soil quality and health hazards. Therefore, it can be concluded that the prevailing dairy farm wastewater disposal system not being satisfactory. The proper disposal system should be improved to reduce environmental impacts.

Mitigating pesticide pollution: A comprehensive study on the biological treatment of clodinafop-propargyl and organic load in agricultural wastewater using a moving bed biofilm reactor (MBBR)

The widespread use of pesticides in modern agriculture poses significant threats to public health and the environment. Addressing the growing environmental and economic concerns requires effective strategies for removing and mitigating agricultural toxins. This study evaluates the efficiency of a Moving Bed Biofilm Reactor (MBBR) in degrading clodinafop-propargyl (CF) and reducing organic matter in a controlled laboratory setting. The research focuses on initial CF concentration and hydraulic retention time (HRT) as key factors influencing removal efficiency. The biodegradation of CF was systematically carried out using the MBBR bioreactor. Results demonstrated maximum removal efficiencies of 82.51 % for CF, 88.78 % for Chemical Oxygen Demand (COD), 89.58 % for Total Phosphorus (TP), and 86.31 % for Total Nitrogen (TN). These findings highlight the MBBR's strong capability in eliminating CF and reducing nitrogen in wastewater, positioning it as a cost-effective and environmentally sustainable solution for pesticide pollution. The novelty of this study lies in its detailed examination of the MBBR's performance under varying operational conditions, providing critical insights into its efficiency and optimization. Overall, this research offers valuable contributions to environmental engineering, presenting a promising method for treating pesticide-laden agricultural wastewater and supporting sustainable farming practices.

Persistent luminescent ZnAl-LDH nanosheets for all-weather degradation of nitenpyram and tetracycline: Superoxide radical induction, life cycle analysis and engineering applications

Photocatalysts designed for all-weather applications, capable of efficient charge carrier separation, are set to transform the adoption of photocatalysis-driven advanced oxidation processes in wastewater management. In this investigation, an energy-storing ZnAl-LDH@SrAl2O4:Eu2+, Dy3+ (SALDH) was synthesized successfully, optimized for the photocatalytic selective degradation of NTP and tetracycline hydrochloride (TC) under varying weather conditions, with 100 % degradation of both NTP and TC within 75 min. Remarkably, SALDH demonstrates energy storage capabilities that markedly reduce energy demands relative to traditional photocatalytic approaches. The primary reactive species identified were O2−, and the Fukui index, computed via density-functional theory (DFT), identified the specific interaction sites of O2− on NTP molecules. Utilizing the energy retention properties of SALDH, a novel, environmentally friendly device was engineered for processing organic pollutants in agricultural wastewater. This system harness the energy from solar radiation to induce the oxidation of pollutants. The experiments that were performed in the both artificially prepared lab-scale and actual agricultural WWT plants indicated the degradation efficiencies of 36 % and 37 %, respectively. As seen during the day, both SALDH and persulfate were capable of effectively decomposing organic contaminants; at night, the SA’s luminescence maintained the oxidative ability of ZnAl-LDH. Meanwhile, SALDH combines the corrosion resistance of ZnAl-LDH with good metal compatibility, enabling SALDH to effectively improve the photostability of long afterglow. This work contributes to the existing knowledge on the degradation of organic pollutants by efficient photocatalysts and points to possible implementations in water treatment processes.

Study on the adsorption mechanism of ciprofloxacin in wastewater by modified fly ash under the coexistence of copper

The recontamination of farming wastewater with antibiotics and metal ions has emerged as a considerable concern in recent years. In this study, fly ash (FA) served as the adsorbent material, and its modified form (AFA) was developed via response surface optimization. The study involved an analysis of the structure and chemical composition of the fly ash before and after modification, both pre- and post-modification, through the use of scanning electron microscopy (SEM), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FT-IR) analyses. These analyses were aimed at exploring the adsorption mechanism of ciprofloxacin (CIP) in the presence of copper ion (Cu2+) in livestock and poultry wastewater. The study indicates that the optimal modification parameters for AFA include an alkali-to-ash ratio of 1.5, a calcination temperature of 400 °C, and a 3-hour calcination period. At pH 6, AFA exhibited a markedly superior adsorption capacity for CIP in comparison to FA, with AFA achieving 19.32 mg/g and FA only 9.61 mg/g. The adsorption process conforms to the quasi-second-order kinetic model and Langmuir isothermal model.The adsorption capacity for CIP increases at low concentrations, specifically when Cu2+ levels are below 100 mg/L. Nevertheless, elevated CIP concentrations impede the adsorption process. The adsorption of AFA for CIP is observed to decrease with rising temperature, in contrast to the adsorption of Cu2+, which increases as the temperature rises. The adsorption mechanism of AFA is primarily comprised of pore filling, ion exchange, electrostatic interaction, π bond coordination, complexation, and other similar processes.

Performance study of phenol sequestration from agricultural wastewater by chemical activated Montmorillonite

Agricultural by-products possess potential as cost-effective adsorbents for the remediation of phenolic contaminants in environmentally treated wastewater. This research focuses on the utilization of Algerian montmorillonite clay, specifically modified montmorillonite (Mo-5N), treated with 5N hydrochloric acid (HCl), compared to its untreated form (Mo-0N), for phenol sequestration from pesticide-laden waters. We employed various analytical techniques, such as chemical analysis, X-ray diffraction (XRD), and Fourier Transform Infrared (FTIR) spectroscopy, to characterize these adsorbents. The adsorption behavior was scrutinized under varying conditions, including pH, contact time, phenol concentration, and temperature. The maximum adsorption capacities achieved were 119.12 mg/g for Mo-5N and 100.89 mg/g for Mo-0N under optimal conditions of pH 5.72, a contact time of 120 minutes, and a temperature of 40°C. The kinetics of adsorption were best described by the pseudo-second-order and Elovich models, while the Freundlich isotherm model aptly described the equilibrium data. Thermodynamic analyses revealed that the phenol removal process using both forms of montmorillonite is spontaneous and endothermic. This study demonstrates the efficacy of Algerian montmorillonite clay in the removal of phenolic pesticides from agricultural wastewater.

Facile fabrication of Cu/kaolin nanocomposite as highly efficient heterogeneous catalyst for 4-nitrophenol reduction in aqueous solution

Hazardous organic pollutants in industrial wastewaters are becoming a major global challenge that threatens life on earth and particularly poses a serious health risk to human beings. 4-Nitrophenol (4-NP) is a highly hazardous organic contaminant that has been extensively utilized across multiple industries, and their wastewater disposal into water streams leads to a higher accumulation of 4-NP. It is therefore important for both academia and industry to make catalysts that are cheap, very effective, good for the environment, easy to recover, and can be used more than once for reducing 4-NP in normal conditions. This paper reports the synthesis, characterization, and application of Cu/kaolin nanocomposite (NC) as an efficient heterogeneous catalyst for decomposing 4-NP, a model organic molecule. The catalyst was synthesized by incorporating a copper precursor into layered kaolin clay and directly reducing the metal precursor using sodium borohydride (NaBH4). The morphology, structure, surface property, and interaction of the resulting Cu/kaolin NC were characterized by ultraviolet–visible spectroscopy, Fourier transform infrared spectroscopy, scanning electron spectroscopy/energy-dispersive X-ray spectroscopy, selected area electron diffraction, X-ray diffraction, and N2 adsorption/desorption, and the results clearly demonstrated the growth of copper nanoparticles on the kaolin surface. It was discovered that the Cu nanoparticles (NPs) on the kaolin surface had a crystallite size of about 23.6 nm. The significance of Cu NPs and the high catalytic activity of the synthesized Cu/kaolin NC toward 4-NP reduction by NaBH4 were evaluated by the catalytic reduction experiments. Among the different nanocomposites synthesized, 30-Cu/kaolin showed the highest catalytic activity for 4-NP reduction, with a reduction efficiency of over 99 % within 4 min with a pseudo-first-order rate constant, kapp, of 1.23 min−1. Furthermore, the reusability test indicated that Cu/kaolin NC can be reused for up to six runs efficiently without significant decrease in its catalytic performance, indicating the nanocomposite has excellent stability and great potential applications in industrial and agricultural wastewater treatment.

Metagenomics reveals the characteristics and potential spread of microbiomes and virulence factor genes in the dairy cattle production system

Virulence factor genes (VFGs) pose a potential threat to ecological security and animal health, and have attracted increasing attention in the livestock industry. As one of the primary livestock types, dairy cattle may be an important source of VFG transmission. However, the distribution, transmission, and evolution of VFGs in the gastrointestinal tract and surrounding environment of dairy cattle remain unclear. In the present study, a total of 263 samples were collected from cows, calves, colostrum, farm wastewater, and soil. Metagenomics was conducted to analyze changes in the microbiome and VFGs characteristics in these ecological niches. The VFGs of the cows showed distinct differences between the rumen and feces, and were influenced by the region. The dominant VFG hosts was regulated by their microbial structure. Colostrum administration of cows increased VFG abundance in their newborn calf feces sharply and Enterobacteriaceae became the primary host. While diet was the primary driving force for the temporal variation in calf VFGs. For samples of the surrounding environment, water and soil had higher VFG concentrations and were more structurally stable. Moreover, extensive interactions between the mobile genetic elements and VFGs and gene mobile analysis map based on metagenomic binning both displayed the potential horizontal transfer ability of VFGs in the cows and environment. Our study revealed the prevalence, diffusion, and regulatory factors of VFGs in dairy cattle production systems, providing novel insights into reducing livestock VFGs and limiting their spread.

The Lasting Effects of Wastewater Irrigation: Evaluating Alkylphenols Accumulation in Soil and Potential Health Risks for Farmers and Local Communities

Reclaimed wastewater is being utilized extensively in agriculture worldwide to tackle water scarcity due to the climate change. However, this practice raises concerns about endocrine-disrupting compounds (EDCs) like alkylphenols (APs) in soil and their potential risks to human health. This study examined the presence of APs in both secondary treated wastewater (STW) and agricultural soil, which had been irrigated with wastewater for about 40 years. The study found significant accumulation of 4-Nonylphenol (4-NP) and 4-tert-Octylphenol (4-t-OP), in the agricultural soil compared to non-irrigated soil. The research also calculated the estrogenic equivalence (EEQ) of APs in agricultural soil and wastewater. The concentrations of APs in the agricultural soil were found to range from 5.33 to 89.0mg/kg dry weight (dw) for 4-NP and from non-detectable levels to 0.2643mg/kg dw for 4-t-OP, while in wastewater, the concentrations ranged from 0.42 to 14.61μg/L for 4-NP and 0.0127 to 0.0635μg/L for 4-t-OP. The study highlighted the potential health risks posed by accidental ingestion of contaminated soil and wastewater with APs, especially for children and adults who might face chronic, subchronic, or short-term exposure. The HQ for exposure to 4-NP in contaminated soil was significantly higher than 1 for chronic exposures involving individuals such as farmers, ranging from 3.35*10-4 to 3.31*102. For subchronic exposures affecting individuals like workers, the health risk ranged from 1.01*10-8 to 1.21*101. The hazard index values for chronic exposure to APs for adults exceed 1. There is a potential non-carcinogenic risk for children, with maximum health risk values significantly exceeding 1.

Development and assessment of vanadium-based metal–organic frameworks for the effective elimination of hazardous pesticides from aqueous solutions: Mechanism of uptake, adsorption capacities, rate of uptake, and enhancement via the Box-Behnken design

Vanadium metal–organic frameworks (V-MOF) has a great potential to remove contaminants from water that come from agriculture wastewater methyl parathion (MP) pesticides with high effectiveness. Using a variety of methods, such as SEM, FT-IR, XPS), XRD, and BET analysis, the adsorbent was successfully synthesized and characterized. The dimensions of the pores measured at 1.33 nm correspond to the classification of micropores under the IUPAC system. Before the adsorption process, the material had a surface area of 1489.42 m2/g and a pore volume of 0.98 cc/g. After MP adsorption, the surface area, pore size, and pore volume decreased to 1268.42 m2/g, 1.12 nm, and 0.64 cc/g, respectively. Changes in the material’s physical properties indicate that the adsorption process had an effect. 7.2 was the result of controlling the point of zero charge through surface characterization. This information suggests that the surface of the adsorbent has a positive charge at pH below 7.2 and at the pH higher than this value the surface will have a negative charge. It was also looked into how pH affected the adsorption equilibrium. Although fitting to Langmuir isothermally, the kinetics of MP adsorption onto V-MOF are pseudo-second-order fitting. It is very probable that chemisorption was the mode of adsorption because the adsorption energy was 23.62 kJ.mol−1. The enthalpy (ΔHo) values obtained as a result of studying the thermodynamic parameters are positive, demonstrating that, within this temperature range, the pesticide adsorption process was endothermic., measuring 32.79 kJ.mol−1. Entropy (ΔSo) readings that are positive indicate that the system’s randomness increased during the adsorption process, reaching 119 J.mol−1K−1, and with rising temperatures, the negative of ΔGo rise. The effectiveness of the recommended adsorbent was evaluated by filtering wastewater samples in a laboratory environment. It is hypothesized that V-MOF and MP will interact by pore filling, π-π interaction, H-bonding, electrostatic contact, and other possible methods. Considering the specifics of this interaction in great detail is essential to comprehending the nature of adsorption and effectively constructing the adsorbent for use in real-world applications. Water filtering and the treatment of industrial effluents were made simple and effective by the use of V-MOF adsorbent technology. The results indicated that 383.6 mg/g was the maximal adsorption capacity at pH = 6. To evaluate the renewal of the adsorbent, more tests were carried out, and the outcomes showed that the renewal continued even after more than six cycles. The stability of the adsorbent during regeneration was confirmed by using XRD and FT-IR. The Box Behnken design (BBD) was then employed to optimize the adsorption outcomes.

Disentangling the Effects of Multiple Impacts of Natural Flooding on a Riverine Floodplain Lake by Applying the Phytoplankton Functional Approach

Riverine floodplains are ecologically remarkable systems that have historically faced strong anthropogenic pressures. The aim of this study was to examine whether the phytoplankton functional approach by Reynolds is a useful tool for disentangling anthropogenic pressure from the impact of natural flooding on a riverine floodplain lake. Lake Sakadaš, part of the large conserved river–floodplain system along the Danube River (Kopački Rit, Croatia), was used as a case study. Historical data on phytoplankton dynamics from the 1970s, when the lake was exposed to direct inflows of agricultural wastewater, were compared with current data from a time when the lake was a strongly protected area. Analysis of the phytoplankton community, based on functional groups and their beta diversities, revealed clear variation between the observed periods. The heavy bloom of species from only one functional group with extremely high biomass indicated a highly impacted environment in the past. Recent data suggest that, with the cessation of direct pollution, near-natural hydrological conditions with flooding as a fundamental environmental driving factor, support algal assemblages characteristic of a naturally eutrophic lake. Assessing multiple pressures on floodplain lakes and disentangling their specific impacts on ecological statuses are crucial for defining the protection and sustainable management of these particularly sensitive and endangered freshwater systems.

Corn stover waste preparation cerium-modified biochar for phosphate removal from pig farm wastewater: Adsorption performance and mechanism

The high phosphorus content in livestock and poultry wastewater is a significant factor contributing to water eutrophication. It is imperative to seek an economically efficient method for phosphate recovery. This study employed cerium-modified biochar to recover phosphate from pig farm wastewater. An investigation was conducted to examine the adsorption performance and removal mechanism of phosphate. Among the different samples, 0.1CeB-500℃ was selected for subsequent experiments. It exhibited a phosphate adsorption capacity of 9.58 mg/g and a removal efficiency of 95.75 %. The results showed that the phosphate adsorption process followed not only the pseudo-second-order kinetic model, but also the Langmuir isotherm model. It suggested that the adsorption of phosphate onto the biochar occurred in a monolayer chemical manner, with a maximum adsorption capacity of 10.86 mg/g. Phosphate adsorption was minimally affected within the pH range of 2–9, with Cl- having negligible impact, NO3- slightly inhibiting, and HCO3- and CO32- significantly hindering phosphate adsorption. A series of characterization results indicated that phosphate removal occurred through surface precipitation forming CePO4, ligand exchange between carbonate and phosphate, inner-sphere complexation, and electrostatic attraction. The phosphate removal efficiency from pig farm wastewater was 43.25 %, demonstrating promising potential for practical application.

Sustainable Approaches used in Pesticides contaminated Agricultural Waste Water Remediation

With the growing population of our global community and thereby increasing the demand for food has led the farmers to use more and more pesticides. Pesticides are chemical compounds used to kill pests. It is commonly used to control various agricultural pests that destroy crops and ultimately affect our agricultural productivity. Although the use of pesticides is a beneficial approach, but unfortunately it also has some drawbacks in terms of harming the environment and human health. Some pesticides pose significant hazards that ultimately affect human health systems. Contamination of agricultural land and agricultural wastewater by pesticides is a serious environmental problem and has a negative impact on biodiversity. Most synthetic pesticides are not readily biodegradable, they accumulate in the environment and cause soil contamination. To overcome the environmental burden of pesticide-contaminated sites, various sustainable approaches can be effectively used to detoxify contaminants or transform them into harmless secondary compounds. The current review focuses on the role of microorganisms and lignocellulosic biomass and plants in the degradation of agricultural pesticides under sustainable approaches.

The removal of antibiotic resistance bacteria and genes and inhibition of RP4 plasmid-mediated conjugative transfer by citric acid chelated Fe(II) catalyzing peroxymonosulfate systems: Performance and mechanisms

The excessive and inappropriate usage of antibiotics accelerated the appearance and proliferation of antibiotic resistant bacteria (ARB) and antibiotic resistant genes (ARGs), posing a considerable threat to human health and ecological systems. The objectives of this study were to construct Fe(II) chelated by citric acid (CA) catalyzing peroxymonosulfate (PMS) systems with different dosages for the elimination of ARB (E. coli DH5α) and ARGs (tetA, tetR, and blaTEM-1), and to reveal the mechanisms on ARGs conjugation transfer. The processes still maintained high ARB/ARGs removal rates in various water matrices (tap water, river water, sewage, and farm wastewater). The results demonstrated Fe(II)-CA/PMS system in high dosages ([Fe(Ⅱ)] = 0.10 mM; [CA] = 0.08 mM; [PMS] = 0.40 mM) significantly enhanced the removal of ARB (8-log) and ARGs (5.11-log tetA, 1.01-log tetR, and 0.62-log blaTEM-1) by promoting the production of reactive oxygen species (ROSs), thereby inhibiting conjugative transfer completely. Interestingly, Fe(II)-CA/PMS treatment at low dosages ([Fe(Ⅱ)] = 0.0025 mM; [CA] = 0.002 mM; [PMS] = 0.02 mM) still inhibited the transfer of ARGs (2.26 × 10−4, 0.65-fold), mainly through downregulation of genes related with ROS synthesis, DNA damage repair (SOS response), ATP synthesis, and transfer-related genes, as well as upregulation of globally regulatory genes. These results presented a hopeful strategy for holding back the dissemination of antibiotic resistance in environments.

Removal of aqueous oxytetracycline using copper-loaded biochar-activated peroxodisulfate: Synergistic mechanism of adsorption and nonradical 1O2

Antibiotic contamination from livestock and poultry farming wastewater has caused substantial adverse effects on the environment and humans. Therefore, in this study, bifunctional adsorption and synergistic degradation of Cu and N codoped biochar (Cu-N/BC) were utilized to efficiently promote the activation of peroxodisulfate (PDS) for removing oxytetracycline (OTC). Cu-N/BC exhibited a high adsorption affinity toward OTC. The adsorption of OTC (50 mg/L) by 0.4 g/L catalyst could reach 36.2 mg/g in 30 min, and the removal of OTC reached 97.24 % in 90 min after adding 0.5 mM PDS. Preadsorption experiments demonstrated that the OTC enriched on the Cu-N/BC surface facilitated the subsequent degradation reaction，its reaction rate constant increases from 0.026 to 0.037. Low-valent copper (Cu0/Cu+), pyridine N, and oxygen-containing functional groups (CO) were the main active sites of Cu-N/BC, and the main contribution toward OTC degradation was from the nonradical pathway of singlet oxygen. Furthermore, potential degradation pathways were revealed, and the intermediates in the OTC degradation process were identified. Cu-N/BC exhibited stable performance, a wide pH application range, and great potential for practical application. This study offers a new concept for designing a bifunctional carbon-based material to remove antibiotics from wastewater.

Ecological Risk Assessment to Aquatic Life from Metals in the Surface Sediments of the Santiago-Guadalajara River Basin, Mexico

ABSTRACT The Santiago-Guadalajara River (SGR) is one of the most polluted river systems in Mexico because there is still a significant amount of untreated industrial, agricultural and municipal wastewater discharged. A sediment monitoring campaign was carried out at 25 sampling points located in the Santiago and Zula rivers, as well as in their main tributaries. In this work, six indices and criteria were selected to assess the level of metal contamination in the main and tributary streams. The following sequence of metals of concern were identified (mean values in mg kg-1 dry basis): Zn (71.92)> Cu (35.22)> Cr (23.82) > Ni (14.95)> Pb (10.82) > As (2.82) > Cd (2.40) > Sb (2.06). Previous studies in the region agree that Al, Fe, Mn, and Ba are part of the natural lithologic composition of the basin, and what is found in the sediments is likely the result of the natural rock weathering processes rather than an anthropogenic contamination process. According to the proposed assess methods Cu, Cr, Ni, Pb, and Zn were found in low to moderate levels of contamination, and Sb and Cd were found in considerable to very high contamination levels in several of the monitored stations.

Surface-coated PVDF@TAPEG selective ultrafiltration membranes: an investigation on membranes’ hydrophilicity, and antifouling characteristics for effective humic acid removal from wastewater

This research aimed to synthesize polyvinyl fluoride membranes and coat them with tannic acid (TA) nanoparticles and polyethylene glycol (PEG) additives so that the membrane’s removal efficacy for humic acid (HA) pollutant from agricultural wastewater was investigated. Thus, six membranes with PEG:TA ratios of 0:0, 1:0, 0:1, 1:1, 4:1, and 1:4 were synthesized. Then, the membranes’ characteristics were identified by FTIR-ATR, FESEM, and AFM analysis, and HA’s particle size and zeta potential were also investigated. Based on optimizing effective parameters, the operating pressure of 1.5 bar and HA concentration of 80 ppm were selected as optimal values. The membrane with PEG:TA = 4:1, as the optimally modified membrane, had a pure water flux of 446.03 L/m2.h, effluent flux of 72.43 L/m2.h, and pollutant removal rate of 86.62% at pH = 7 after 60 min had passed. These values for the pristine membrane (PEG:TA = 0:0) were 265.64 L/m2.h, 89.39 L/m2.h, and 75.59%, respectively. The results showed that although the effluent flux was lower in the optimized modified membrane than in the pristine membrane, HA removal percentage was increased.