The Curve Number method, developed in the 1950s in the United States, is commonly used to estimate runoff depth resulting from heavy rainfall. Over many years, it has been tested in various regions and for purposes beyond its original use. Despite numerous studies on this method, some issues still require consideration, i.e., a universally accepted procedure for CN determination from rainfall-runoff data. In this work, the authors attempt to estimate the CN parameter for a small, lowland catchment in central Poland. Historical data on catchment land cover and original rainfall-runoff measurements are used to determine the CN values for three periods characterized by different catchment land-cover structures. The applied approaches for CN estimation are compared and discussed. The study indicates that: i) over the period 1974-2018, a gradual increase in forested areas was observed, accompanied by a decrease in the average CN value (on average, a 1% increase in forest cover reduces CN by 0.2), ii) among approaches based on rainfall-runoff data, the least-squares calibration appears to be the most straightforward method for CN estimation; while the asymptotic approach may additionally identify a threshold rainfall beyond which the method is applicable; iii) the accepted initial abstraction ratio plays a key role in CN estimation and water-routing modelling, and further research is required to improve runoff prediction.

At the municipal wastewater treatment plant in Międzyzdroje (approximately 6,000 permanent residents; ~370,000 people during the summer season), a tertiary treatment stage based on gravity filtration using disc filters (Mecana SF6/30; PES-13) was implemented between 2021 and 2023. Despite a twofold increase in influent flow during the summer of 2024, the quality parameters of the treated wastewater (TSS, BOD5, COD, TN, and TP) remained well below the limits specified in the water permit. The filtration process effectively stabilized effluent quality under conditions of increased seasonal load. However, only limited removal of selected pharmaceuticals was observed: 7-17% (metoprolol 7%, candesartan 17%, irbesartan 5%, venlafaxine 14%, citalopram 10%, amisulpride 14%) and 33% for clarithromycin. No removal was observed for hydrochlorothiazide, carbamazepine, or diclofenac. Benzotriazole concentrations decreased by only 3%. All 24 PFAS compounds were below the limit of quantification (LOQ), and the Σ16 PAHs concentration was <0.21 Sg/L. These results confirm that effective reduction of micropollutant emissions requires the implementation of a quaternary treatment stage (e.g., advanced oxidation processes, adsorption, or membrane technologies).

This study assessed the awareness, understanding, and practices of household waste recycling in high-income and low-income communities in the North of Pretoria, South Africa. A structured questionnaire was administered through face-to-face interviews and a door-to-door survey. A purposive sampling involving 122 participants was carried out. Data were collected from September 2023 to April 2024 and analyzed using descriptive statistics and the Pearson chi-square test. The study area was divided into four sites (A, B, C, and D) based on income levels. At sites A, B, and C (low-income communities), 81.6%, 81.4%, and 75.0 % of participants, respectively, did not separate waste, whereas at Site D (high-income community), 61.5% of the participants did not separate their household waste before disposal. Participants from all the communities were aware of recycling in the following order: Site D (76.9%) >Site C (60.7%) >Site A (60.5%) >Site B (51.2%). However, actual recycling rates remained low, with only 30.7% of high-income and 15.8% to 20.1% of low-income participants partaking in recycling practices. Lack of time and inadequate infrastructure were identified as major obstacles to household waste recycling. Recycling was only carried out when there was a perceived financial benefit. Despite their knowledge of recycling, most participants did not recycle their household waste. Awareness campaigns and incentives ought to be introduced to encourage recycling and boost community participation. The establishment of local recycling centres could enhance engagement in recycling, resulting in employment opportunities.

Non-steroidal anti-inflammatory drugs (NSAIDs ), widely used for their analgesic and anti-inflammatory properties, are increasingly recognized as emerging contaminants in aquatic environments. Despite their therapeutic value for humans, their persistence, bioactivity, and widespread use contribute to continuous input into surface waters through wastewater effluents and agricultural runoff. This review provides a comprehensive synthesis of the current knowledge regarding the occurrence, distribution, and ecological impacts of NSAIDs in aquatic ecosystems. We examine the primary sources of emission, the physicochemical properties influencing their transport and bioaccumulation, and analyze global monitoring data on concentrations of key NSAIDs in freshwater systems. Particular attention is given to their effects on various aquatic organisms, including bacteria, phytoplankton, zooplankton, invertebrates, and vertebrates, with documented outcomes such as developmental abnormalities, physiological disruptions, and oxidative stress. Risk assessment metrics, such as risk quotients (RQ) based on predicted or measured environmental concentrations and predicted no-effect concentrations (PNECs), are evaluated to highlight zones of heightened ecological threat. Finally, we discuss the implications of current trends, forecast future risks, and suggest directions for mitigation through improved wastewater treatment technologies, regulatory measures, and public awareness. NSAIDs, often perceived as benign pharmaceuticals, represent a silent but significant ecological risk requiring urgent interdisciplinary attention.

The Pszczyna commune in southern Poland has long faced poor air quality, especially during the heating season. This study assesses the effectiveness of a local policy to reduce PM10 and PM2.5 concentrations by replacing old solid-fuel boilers with low- or zero-emission systems. Using data on air quality from monitoring stations for the two years 2020 and 2023 as well as meteorological records, and administrative reports on the scale and scope of boiler replacements, the analysis applies statistical comparisons, meteorological normalization, and regression analysis to isolate commune policy effects from weather variability. Results show a significant reduction in PM levels, particularly in winter, with PM10 decreasing by over 30% and PM2.5 by up to about 40%. These findings confirm the effectiveness of targeted residential heating interventions and highlight how local actions, supported by regional and national funding, can yield measurable environmental and health benefits within a short period. Continued monitoring and public engagement are essential to sustaining air quality improvements.

Water bodies contaminated with heavy metals have generated significant concern worldwide due to their toxicity, persistence, bioaccumulation, and non-biodegradability. Among these pollutants is Pb (II), which enters water sources primarily as a result of anthropogenic activities. Prolonged exposure to this contaminant can cause neurological disorders, as well as respiratory and urinary issues. This research aims to model an industrial-scale packed column using Computer-Aided Process Engineering (CAPE) to remove Pb (II) from an aqueous solution, using Theobroma cacao L. as bioadsorbent. Using Aspen Adsorption, several simulations were bperformed on adsorption columns with varying configurations at an industrial scale, evaluating the parametric sensitivity to bed height, inlet flow rate, and initial concentration. The results showed that the simulated adsorption columns achieved removal efficiencies of up to 99%. The optimal simulation conditions for the column simulation included a bed height of 5 m, an initial concentration of 3000 mg/L, and an inlet flow rate of 50 m3/day. It was observed that increasing the inlet flow rate reduced the breakthrough and saturation times of the process, while increasing the bed height extended these times. These findings demonstrate the potential of computational tools as valuable alternatives for predicting the performance of adsorption columns packed with biomass.

The main aim of the study was to achieve a better understanding of the chemical composition, seasonal variation, and sources of ambient particulate matter in two mid-sized towns in Southern Poland, characterized by a significant air pollution issues: Nowy Targ and Zabierzów. Daily PM10 samples were chemically analyzed for the content of water-soluble ions, carbonaceous matter and trace elements. Positive Matrix Factorization (PMF) was applied for source apportionment. The annual mean PM10 concentrations were 38 μg/m3 and 41 μg/m3 in Zabierzów and Nowy Targ, respectively. Secondary species (SIA + SOC) constituted, on average, 23% of PM10 in Nowy Targ, while in Zabierzów, this share varied from 32% to 41% during the non-heating and heating seasons, respectively. The proportion of primary pollutants (EC + POC) in PM10 substantially increased during the heating season in both locations, reaching 24% and 37% of PM10 in Zabierzów and Nowy Targ, respectively. PMF analyses identifies four sources with similar profiles at both sites: residential coal combustion, residential wood combustion, road transport, and secondary aerosol. In both locations, residential coal and wood combustion were the largest contributing sources (on average 44% and 50% of PM10 in Zabierzów and Nowy Targ, respectively), followed by road transport (on average 14% and 21% of PM10). Local sources were the dominant contributors to PM10 at both sites, accounting for 86% and 90% of PM10 in Nowy Targ and Zabierzów, respectively. These findings underscore the importance of implementing control strategies tailored to local factors to improve air quality in these towns

With the gradual increase of microplastics in water bodies, it is essential to understand the current treatment processes for their removal. This study aims to investigate the removal of microplastics in synthetic solution by electrocoagulation (EC). The effects of electrode type, contact time (min), agitation speed (rpm) and current density (A/m²) were evaluated using a fractional factorial design. The results showed that the aluminum anode achieved a higher removal of microplastics than the iron anode, reaching 98.04% removal with the aluminum operational configuration within 15 min at 70 rpm and a current density of 20 A/m². A high correlation between the predicted and observed removal was evidenced, with values of R²= 0.99 and adjusted R²= 0.98, indicating a good agreement between the model and the experimental data, confirming the validity and feasibility of the adopted linear model. This study demonstrates that the electrocoagulation process has a great potential for the removal of microplastics.

Wastewater treatment and the efficient use of sewage sludge biochar are critical in addressing the needs of ever-increasing population in the world. Recently, phosphorus (P) removal from wastewater has become highly relevant and important, primarily to reduce eutrophication in surface waters. Using sewage sludge biochar as an adsorbent for phosphate removal from wastewater offers an opportunity to reuse sewage sludge (SS) and return phosphorus to the biogeochemical cycle. In this study, the efficiency of two phosphate removal methods - batch adsorption and fixed-bed column process – was investigated using pyrolyzed sewage sludge biochar (PSSB) produced at different temperatures (300 °C, 400 °C, 500 °C, 600 °C). In the batch adsorption experiment, direct mixing of 600 °C pyrolyzed sewage sludge biochar with wastewater resulted in a relatively low phosphate removal efficiency (only about 18 %) at an initial phosphate concentration of 100 mg/l. In contrast, the fixed-bed column process, using PSSB as a filter for phosphate adsorption, showed significantly better results. The highest phosphate removal efficiency (up to 90%) was achieved after 30 min of filtration, using an initial phosphate concentration of 30 mg/l initial and biochar pyrolyzed at 600 °C.

The employment of green synthesized nanomaterials for water pollution prevention is increasing nowadays. Herein, Mn-doped ZnO nanoparticles were synthesized using Peganum Harmala seed extract and subsequently used for crystal violet (CV) dye removal from aqueous solutions. The first part of the study describes the preparation of the adsorbent (Mn-ZnO NPs) using a simple coprecipitation method. The surface properties of the material were characterized by Fourier transform infrared spectra (FTIR), scanning electron microscopy (SEM), and X-ray diffraction (XRD). The second part investigates the adsorption of CV dye onto the surface of the prepared Mn-ZnO NPs. Additionally, the isotherm,kinetics, and thermodynamics of the adsorption process were studied in detail. Batch adsorption analysis was carried out by evaluating different parameters, such as the amount of the adsorbent (0.01g to 0.04 g), CV concentration (20 to 80 mg/L), adsorption time (30 to 120 min), and temperature (35 to 65 ⁰C). The maximum CV dye adsorption capacity of the Mn-ZnO NPs was 45.60 mg/g. The thermodynamic study revealed the spontaneous, exothermic, and feasible nature of the adsorption process, primarily driven by physical forces. Kinetic and isotherm analyses indicated that the adsorption of the dye best fit the Freundlich isotherm and pseudo-second-order models, respectively. Mn-doped ZnO is considered an effective adsorbent for CV, benefiting from its rapid and easy preparation, non-toxic nature, and 94 % adsorption efficiency. The material holds potential for future applications in the removal of organic dyes from wastewater.