This study investigated the acute inhibitory impacts of two widely used antibiotics, erythromycin (ERY) and tetracycline (TET), on ammonia-oxidizing bacteria (AOB) and nitrite-oxidizing bacteria (NOB) within an enriched nitrifying culture. For this purpose, a lab-scale wastewater treatment system sustaining enriched nitrifiers was exposed to antibiotic concentrations ranging from 25 to 100 mg L[-1]. Model evaluations of oxygen uptake rate (OUR) evolution, together with ammonia and nitrite oxidation profiles, revealed distinct metabolic disruptions. ERY severely impaired the system, dropping overall nitrification efficiency to as low as 25% and halving the growth rates for both AOB and NOB. In contrast, TET exposure largely maintained overall nitrification performance with slightly reduced NOB activity. Under TET stress, the half-saturation constants for ammonia (KNH) and nitrite (KNO) increased to 32 and 2 mg N L[-][1], respectively, indicating competitive inhibition and decreased substrate affinity. Both antibiotics reduced heterotrophic activity - more severely with ERY-triggering the release and utilisation of hydrolyzable biomass fractions. The results demonstrate that acute antibiotic toxicity and inhibitory impacts are markedly less pronounced in enriched nitrifying systems compared to conventional mixed activated sludge systems.

Dairy wastewater air flotation sludge (DWAFS) is resistant to conventional mechanical dewatering due to its high fat content and protein-stabilized emulsion structure. To address this challenge, this study employed electron beam (EB) irradiation as a pretreatment method. The effects of irradiation dose on sludge dewaterability were systematically investigated, and the multi-dimensional underlying mechanisms were elucidated through integrated multi-scale characterization. The results showed that EB irradiation significantly enhanced dewaterability, with 5 kGy identified as the optimal dose based on a combined evaluation of dewatering performance and specific energy consumption. EB irradiation was shown to efficiently disrupt the protein-stabilized emulsion, likely via water radiolysis-derived free radicals. This process is proposed to drive organic component transformation, surface charge neutralization, protein-lipid co-aggregation and floc reconstruction, ultimately contributing to the conversion of bound water to free water and enhanced dewaterability. These findings clarify the demulsification-dewatering coupling mechanism of EB irradiation on DWAFS and provide a theoretical basis for engineering application in high-fat oily sludge treatment.

This study characterizes the dynamic development process of photogranules, explores the role of related substances in their formation, and verifies the resource recovery potential in nitrogen and phosphorus removal from wastewater. The characteristics of photogranules were observed, and the nitrogen and phosphorus removal efficiency of the system was measured. The content of protein and polysaccharide in extracellular polymeric substances was determined over time. Excitation-emission matrix fluorescence was used to analyse the types and changes of substances in the system. Resource recovery assessments were conducted by adopting the method of freeze-thaw combined with trituration to extract phycocyanin and determine the content of phycobiliprotein. Photogranule development went through three sequential phases: initially, photogranules were under 1 mm in diameter, with peripheral filaments proliferating to create an irregular, meteorite-like surface; densification: loosely woven filaments contracted, increasing density and reducing surface pits, forming more compact structures; at maturation, granules reached approximately 1.3 mm and became spherical. The system achieved approximately 98% nitrogen and 56% phosphorus removal. Protein and polysaccharide content in extracellular polymeric substances increased slightly over time. Excitation-emission matrix fluorescence showed abundant humic-like substances in the early phase, while microbial byproducts and aromatic proteins remained stable later. The freeze-thaw combined with trituration yielded the highest concentration of phycocyanin (0.31 mg L[-1]), with phycobiliprotein content stable at about 50 mg L[-1]. This study describes photogranule growth characteristics, confirms the structural role of EPS, and demonstrates the dual functionality of photogranules in nutrient removal and resource recovery.

Aquaculture wastewater commonly contains excess nutrients and residual antibiotics, whereas conventional plant-only ecological ponds may provide insufficient removal of these coexisting contaminants. To enhance system performance through substrate engineering, iron-modified oyster shell biochar (IOBC) was developed as a functional medium and coupled with Myriophyllum in an ecological purification system. Response surface methodology identified optimal IOBC preparation conditions of 700 °C, a modification ratio of 1:1, and 3.5% iron addition, under which oxytetracycline (OTC) removal reached 89.37%. The optimized IOBC was subsequently incorporated into a continuous-flow system treating simulated aquaculture wastewater. In the continuous-flow system treating simulated aquaculture wastewater, pollutant removal increased with hydraulic retention time, and the coupled IOBC-Myriophyllum treatment consistently outperformed the filler-only and plant-only systems. At 72 h, the coupled system achieved removal efficiencies of 38.89% for NH4[+]-N, 38.79% for TN, 72.81% for TP, 67.67% for CODMn, and 59.46% for OTC. Sequencing and mechanistic analyses indicated that the enhanced performance resulted from coordinated adsorption, plant uptake, microbial nitrification and denitrification, Ca- and Fe-mediated phosphorus precipitation, and oxidative and biological transformation of OTC. These findings demonstrate that functional substrate modification can strengthen ecological treatment of nutrient- and antibiotic-containing aquaculture wastewater.

The increase in sheep populations to meet the demand for meat generates large volumes of sheep wool, most of which is considered agro-industrial waste and poses a potential risk of contamination due to improper handling. Protein recovery is an attractive strategy for generating agricultural inputs, such as protein hydrolysates (PHs). This study aimed to evaluate the agrobiotechnological potential of sheep wool-derived PHs as (i) an alternative peptone source for Trichoderma harzianum and (ii) growth-promoting inputs in hydroponic green fodder (HGF) production. To this end, an alkaline-enzymatic hydrolysis process was evaluated, incorporating pretreatment with an anionic surfactant applied to sheep wool. SDBS-pretreated wool underwent alkaline solubilization (2.5% NaOH) followed by enzymatic hydrolysis using Esperase® or papain. The process achieved 90-92% solubilization and 29-39% hydrolysis, producing peptides of 10-2 kDa and increasing soluble nitrogen and primary amino groups. Compounds with reducing capacity were also detected without affecting antioxidant activity (FRAP and DPPH), particularly in the Esperase®. Sheep wool hydrolysates used as a peptone source promoted moderate mycelial growth and sporulation of T. harzianum, while enhancing enzymatic activity associated with biological control potential, as indicated by increased halo diameters. Furthermore, foliar application of hydrolysates at 3 g L[-][1] in HGF promoted greater shoot length (8.2-9.6%) and higher total protein content (27.2%) compared to the control, along with an increase in dry matter content (4.1%). Overall, alkaline-enzymatic hydrolysis of sheep wool represents a promising strategy to produce bio-based inputs for microbial culture and plant growth.

This study compared the concentrations, operationally defined chemical fractions, and screening-level environmental risks of Cu, Cr, Zn, Cd, Ni, and Pb in 20 dewatered sludge samples collected from drinking-water treatment plants (DWTPs; n = 3), municipal wastewater treatment plants (MWWTPs; n = 11), and industrial wastewater treatment plants (IWWTPs; n = 6) in Taiwan. A modified BCR sequential extraction procedure was used to separate acid-extractable (F1), reducible (F2), oxidizable (F3), and residual (F4) fractions. MWDWTP sludge contained comparatively high Zn and Cd concentrations, whereas several IWWTP samples showed elevated Cu, Cr, Ni, and Pb. Cu, Cr, Ni, and Pb were frequently associated with F3 and/or F4, while Zn and Cd showed substantial F2 contributions at several sites. Concentration-based indices identified marked enrichment at selected facilities, whereas fraction-based indices indicated that mobility depended on both metal and sludge category. High Igeo values therefore represent enrichment relative to background and do not necessarily indicate high immediate mobility when metals occur mainly in F3 or F4. These results support site-specific evaluation of total metal loads and chemical fractionation before sludge reuse, treatment, or disposal.

The study evaluates the degradation of a mixture of frequently detected endocrine disrupting chemicals in municipal wastewater using six sequential biological-advanced oxidation treatment systems. The evaluated systems include UV, H2O2, and UV/H2O2 applied before or after biological treatment. The performance of the conventional municipal treatment plant was compared with sequential processes under previously optimized operating conditions (pH ≈ 5 (AOP), 7 (bio), 450 W UV power, 2.0 mM H2O2, reaction time for AOP: 60 min, and bio process: 6 h). The conventional system achieved only 36.41 ± 0.53% to 55.11 ± 0.48% removal of the mixture of target EDCs, whereas the bio/UV/H2O2 was the most effective, achieving complete diethyl phthalate removal and >90 ± 0.65% of butyl paraben and bisphenol A, with 90.5 ± 1.33% reduction in chemical oxygen demand. The pseudo-first-order kinetic analysis indicated an enhanced degradation efficiency, with a maximum rate constant of 0.0048 min[-][1]. The energy consumption ranged from 9.47 × 10[2] to 1.56 × 10[4] kWh kg[-][1] COD, with the operating cost primarily driven by electricity (≈0.16 USD L[-][1]). These findings provide mechanistic and comparative insight into hybrid treatment performance under controlled conditions; however, validation under environmentally relevant concentrations and continuous-flow systems is required before practical implementation.

Wastewater utilities require a systematic method for screening agro-industrial co-substrates before testing them in sewage-sludge digesters. This study developed and applied a hierarchical preliminary screening framework based on physicochemical characterisation, biochemical methane potential assays, first-order kinetic modelling, and volumetric methane production. Seven waste streams were evaluated individually: a fat-rich fraction recovered from meat-processing wash water, four meat-processing wash waters, used cooking oil, and confectionery-production wash water. Eight fixed-ratio mixtures were then assessed using selected meat-processing streams, cheese whey, olive mill wastewater, and winery wastewater. Specific methane production of the individual waste streams ranged from 0.087 to 0.969 m[3] CH4 kg[-][1] VS. Across the mixtures, final SMP ranged from 0.390 to 0.855 m[3] CH4 kg[-][1] VS and t90 from 9.0 to 23.3 d. TS, VS, and COD were associated with volumetric methane production at days 10 and 30 but not with final SMP, k, or t90. The COD-VMP10 and TS-VMP30 models explained 87.5% and 86.0% of the variability, showing that volumetric methane output was influenced by feedstock concentration. Biochemical compatibility was classified using final SMP, t90, and evidence of sustained methane suppression; VMP10 and VMP30 then refined priorities within each category. The cheese whey + meat-processing wash water R2 mixture (M1; 1:1 v/v) was prioritised because it combined high SMP (0.792 m[3] CH4 kg[-][1] VS), rapid apparent conversion (t90 = 11.8 d), and the highest volumetric relevance. The framework converts physicochemical and BMP-derived results into a traceable basis for selecting external co-substrates for subsequent controlled validation with municipal sludge.

This study evaluated the removal and behavior of linear alkylbenzene sulfonate (LAS) in pilot-scale integrated anaerobic-aerobic wastewater treatment systems, which were tested at different effluent recirculation rates (0%, 50%, and 100%). The systems combined UASB reactors and anaerobic filters with activated sludge reactors and submerged aerated biofilters treating typical domestic sewage. LAS concentrations, loads, adsorption, and chromatographic profiles of homologues and positional isomers were investigated to better understand the mechanisms that govern surfactant removal under different hydraulic conditions. The influent LAS concentrations ranged from 2.55 ± 0.34 to 3.43 ± 1.31 mg L[-][1]. Aerobic units consistently showed higher LAS removal efficiencies than anaerobic units, achieving a peak removal of 75 ± 17% and an overall system removal of 68 ± 38% at a recirculation rate of 50%. Conversely, higher recirculation rates increased hydraulic loading and promoted LAS desorption in anaerobic units, resulting in higher LAS loads during some treatment stages. Chromatographic analyses indicated that aerobic units selectively biodegraded LAS positional isomers, while adsorption was the dominant process in anaerobic sludge. The results demonstrate that LAS removal in integrated anaerobic-aerobic systems is governed by interactions among hydraulic conditions, adsorption/desorption processes, and aerobic biodegradation, providing practical insights for optimizing surfactant removal in wastewater treatment systems.

Textile industry wastewater consists of colored wastewater containing high concentrations of organic matter, complex components, reactive dyes, and chemical residues. While reverse osmosis (RO) membrane systems are frequently used to sustainably manage high-volume wastewater streams, they also produce a concentrated, resistant, and nonbiodegradable effluent. In this study, the photo-Fenton process was applied and optimized using Box-Behnken Design (BBD) to treat RO concentrate containing high concentrations of toxic and pollutant species. H2O2/COD, Fe[2+]/H2O2, and reaction time were selected as operating parameters, while COD, color index (CI), ultraviolet absorbance at 254 nm (UV254), and ultraviolet absorbance at 280 nm (UV280) removal efficiencies were selected as model responses. Statistically, the model's fits were evaluated using variance analysis. Numerical analysis determined the optimum process conditions as H2O2/COD 2.0, Fe[2+]/H2O2 0.25, and reaction time 68.4 min at pH 3.0. Under optimum conditions, the validation experiments demonstrated that the photo-Fenton process achieved removal efficiencies of 78.5% for COD, 96.6% for CI, 82.5% for total suspended solids, 92.8% for UV254, and 85.0% for UV280. The calculated operating cost of the process was 14.3 €/m[3]. The obtained results showed that the applied photo-Fenton process effectively removed pollutants from RO concentrate, and that the BBD could be used to optimize its operating conditions.

In nature, fungi play a leading role in the biodegradation of organic waste by secreting a broad spectrum of lignocellulolytic enzymes (cellulases, hemicellulases, and ligninases). Inspired by this natural ecological synergy, in the present study, two promising fungal isolates, Trichoderma sp. isolate HR27 and Ganoderma sp. isolate HR31, were isolated and assessed for biocompatibility. Subsequently, their consortium was utilized for single-factorial optimization of various parameters (inoculum size, incubation time, lignocellulosic substrate, temperature, moisture content, pH, surfactant, nitrogen source, co-substrate, and inducer) under solid-state fermentation (SSF) using lignocellulosic waste for enhanced lignocellulolytic enzyme production. The results revealed that a significant increase in enzyme yield was achieved by utilizing wheat straw as the substrate, supplemented with 1.5 g/L Tween 80 and 0.5 mM CuSO4 in Asther's medium with an initial pH of 3.5 at 30˚C. Compared to unoptimized media, optimized media resulted in 5.99, 5.18, 1.13, 2.57, 4.97, and 2.68-fold increases in endoglucanase, exoglucanase, β-glucosidase, mannanase, xylanase, and laccase production, respectively, on the fourth day of fermentation. Compositional analysis revealed that enhanced enzyme production under optimized conditions resulted in 31.7% delignification of wheat straw; however, only 22.9% was observed under unoptimized conditions, compared to that of the raw substrate. The removal of lignin resulted in higher exposure of cellulose (43.25%) and hemicellulose (24.85%) contents in wheat straw under optimized conditions. These findings highlight the potential of the fungal consortium as an effective candidate for lignocellulolytic enzyme cocktail production for various industrial applications using agricultural waste with concurrent valorization of agro-waste.

The non-compliant discharge of electroplating wastewater containing nitrate (NO3[-]-N) and heavy metals (HMs) harms aquatic ecosystems and makes it more difficult to control water pollution. This study prepared manganese-modified corn silk (Mn/CS) composite mycelial pellets (Mn-CMP) by combining Mn/CS with the fungal strain Alternaria sp. YNX. These Mn-CMP were then used as novel immobilized carriers to immobilize the strain Zoogloea sp. ZY8 to construct a dual-species immobilized bioreactor. Under optimal conditions, with influent concentrations of 20.0 mg L[-1] NO3[-]-N, 1.0 mg L[-1] Zinc(II) (Zn(II)), and 1.0 mg L[-1] nickel(II) (Ni(II)), the bioreactor achieved simultaneous removal of NO3[-]-N at 97.50%, Zn(II) at 99.50%, and Ni(II) at 96.87%. During this process, manganese (Mn) oxides acted as electron shuttles and active sites to enhance electron transfer, while oxygen-containing functional groups promoted HMs adsorption, and bioprecipitation further facilitated HMs immobilization. Furthermore, high-throughput sequencing revealed core functional genes for nitrogen and energy metabolism, which microorganisms regulated to respond to environmental changes. This study provided a new perspective for using Mn-CMP to immobilize functional bacteria to treat industrial wastewater co-contaminated with NO3[-]-N and HMs.

To address the challenges of prolonged start-up cycles and poor operational stability in biofilm reactors for treating high ammonia nitrogen pollution in aquaculture effluent, this study adopted fulvic acid (FA) as a novel biofilm enhancer to systematically analyze its regulatory mechanisms on denitrification performance and biofilm formation in sequencing batch biofilm reactors (SBBR). Through microplate biofilm formation experiments and SBBR process validation, researchers found that the biofilm formation index reached 1.4 at an FA concentration of 1200 mg/L. FA improved biofilm structural stability by promoting extracellular polymer secretion, yielding a 22-fold increase in biofilm thickness compared with the control group (the biofilm thickness peaked at 2208.3 μm). Additionally, high FA concentrations (>500 mg/L) strengthened denitrification processes by facilitating carbon source supply and electron transfer, enriched denitrifying functional bacteria such as Comamonadaceae, and inhibited Gram-positive bacteria (e.g., Actinobacteriota). The removal efficiencies of NH4[+]-N, NO3[-]-N, and total nitrogen reached 79.67%, 80% and 62.4%, respectively. This study reveals that FA enhances SBBR denitrification through dual mechanisms of carbon source supplementation and physicochemical property regulation, providing an efficient and cost-effective regulatory strategy for aquaculture effluent treatment.

To properly manage the challenges of small legacy landfill operations in remote areas such as Northern Ontario, it is important to accurately delineate areas of buried waste. A proper delineation of buried waste is required for site life calculations, future development planning and site closure planning. Traditional methods of waste delineation, such as test pitting, can be destructive, expensive and limited by poor site access. This study aims to delineate buried waste at three separate trench-and-fill style landfills using a Frequency-Domain Electromagnetics (FDEM) survey. The results of the FDEM survey were compared to the results of concurrent traditional test-pitting programmes. The EM31-MK2 was successful in accurately determining the lateral extents of buried waste compared to the results of the test-pitting programme. Other geophysical survey methods, used with FDEM surveys, may improve measurements of waste thickness. The calculated areas of buried waste from the FDEM survey were within 6% of the calculated area from the test-pitting programme, with the exception of one site with a large area of thin buried waste. The calculated volumes of waste using the FDEM survey were within 15% of the calculated volumes of waste using the test-pitting programme. Additionally, the area of waste delineated by the FDEM survey had a 70% overlap with the area of waste defined by the test-pitting programme. The accurate delineation of buried waste, combined with the manoeuvrability and ease-of-use of the EM-31 MK2, make it an effective tool for lateral waste delineation at small landfilling sites.