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Most industries are responsible for environmental pollution because their wastewater contains heavy metals that are hazardous. These metals tend to persist indefinitely in the environment, compromising not only human health but also the well-being of ecosystems. The objective of this study was to analyze the adsorption technology for removing heavy metals in industrial wastewater, evaluating influencing factors, adsorbent materials, applied isotherms and their advantages, through a systematic review of the scientific literature of the last 10 years. To conduct this research, the Scopus digital database was consulted. The search was conducted using a systematic review methodology and the PICO framework to identify, analyze, and interpret data on adsorption technology, factors influencing adsorption, the efficiency of different materials used as adsorbents, and the advantages and disadvantages of adsorption isotherms. To filter the information, the guidelines of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement were followed, which allowed the articles to be selected to answer the research questions posed in this study. Based on the results, it was found that the factors influencing the adsorption of heavy metals include pH (range of 3–9), contact time (range of 10–14,400 min), adsorbent dosage (0.011–20 g/L), temperature (25–30 °C), particle size, and agitation speed (100–800 ppm). Among the most efficient adsorbents are acacia cellulose lignin with 99.8% Cr, bentonite clay with 99% Cu, 96% Cd, and 99% Pb, modified sugarcane bagasse with 96.9% Cu, and activated carbon with 82.8% Cr at pH 3. The least efficient adsorbents are natural moss (54.5% Cr) and biochar from corn husks (20% Cr). The Freundlich isotherm model is the most used, and it can vary depending on the type of adsorbent, the correlation coefficient fit, and the type of heavy metal being treated. Finally, the advantages and limitations of some adsorbents are presented, primarily highlighting their low costs, reusability, and the sustainability they can offer in reducing environmental pollution.

This study aimed to compare the water age in a drinking water distribution network (DWDN) using tracers and EPANET. The results indicate that all DWDN have residence times within the “short” time. established by the EPA and does not represent quality problems. These two techniques provided similar estimates of water age with small differences at points close to the treatment plant. This difference may be due to the fact that tracers can be retained in pipes, which overestimates the age of the water; meanwhile, EPANET could underestimate residence times due to the calibration or simplified representation of the network.

This article presents a set of data obtained during the evaluation of a horizontal flow tubular flocculator for the provision of drinking water in developing communities. The HFTF is presented as an alternative technology to replace conventional flocculators, allowing high efficiency in the subsequent sedimentation and filtration processes. For obtaining the data, experimental tests were carried out using lengths of 68.4 m and 97.6 m for the HFTF, these lengths were combined with flow rates of 0.25, 0.5, 0.75, 1.0 and 2.0 L/s, as well as raw water turbidities of 10, 20, 50, 100 and 200 NTU. The data set generated from measurements and observations made during experimental field tests is detailed. The resulting data set covers the main parameters that determine the quality of drinking water, such as turbidity and colour, as well as flocculation efficiency data. The data from the experimental system were compared with a conventional treatment plant that has a baffle flocculator. Likewise, data on the retention time and velocity gradient are presented that allowed the hydraulic characteristics of the HFTF are evaluated. This data set has significant potential for reuse in future research and development related to water treatment technologies in developing community settings. Detailed data has been collected on various operating conditions of the HFTF, such as different lengths, water flow rates and turbidity levels, as well as measurements of key parameters such as turbidity, colour, flocculation efficiency, retention time and velocity gradient, these Data could be used in future research and development related to water treatment technologies. Furthermore, a comparison of data from the experimental system with a conventional treatment plant provides useful insight into the relative performance of different water treatment technologies, which could be of interest to researchers, system designers and public policymakers in the field of drinking water supply in developing communities.

The main objective of this study was to evaluate the impact of the length and retention time of a tubular helical flow flocculator (THFF) on the elimination of turbidity and color from raw water, to obtain quality treated water for consumption in areas rural. For this, a large-scale field experimental system was used, the THFF was built with 4-inch diameter polyethylene hose and coupled to a sedimentation and filtration process. For the different experimental tests, aluminum sulfate was chosen as the coagulant. To find the optimal dose of coagulant, jar tests were previously carried out. For the tests the length of the THFF was varied (50 m and 75 m), flow rates of 0.25, 0.5, 0.75, 1 and 2 L/s and turbidity ranges of 100 NTU of raw water were tested. An evaluation of the hydraulic behavior of the THFF was carried out through an analysis of the temporal distribution curve of the concentration of a tracer, applying the Wolf-Resnick model. The average results revealed a haze and color removal efficiency of 98.07 % and 98.50 %, respectively. The residence time and velocity gradient exhibited variations in a range of 2.25–35.0 min and 3.64 to 56.94 s−1, respectively. It was evident that the operation and effectiveness of THFF are directly influenced by the turbidity of the raw water, the residence time and the velocity gradient. These findings indicate that THFF could play a valuable role as a flocculation unit in a purification system, mainly the existence of a plug-type flow was observed. The findings indicate that THFF, complemented by settling and filtration processes, could be a valuable tool for implementation in rural areas.

Cleaner Production, as an environmental strategy, is integrated into processes, products, and services to increase efficiency and reduce risks to people and the environment. However, Cleaner Production management in water treatment services does not receive much public attention. To address this need, a scientometric analysis of the integration of Cleaner Production in water treatment was developed to investigate the efficacy and limitations of various Cleaner Production strategies applied in water treatment. A search was carried out in the Scopus database using the keywords ``Cleaner production,'' ``Wastewater treatment,'' and ``Drinking water treatment'' between January 1, 2002, and October 31, 2022. Through the scientometric analysis, it was possible to identify that Cleaner Production has been little applied in drinking water treatment. The reason for this was a systematic review of the application of Cleaner Production in drinking water treatment. The data and information obtained were filtered following the guidelines of the Preferred Reporting Declaration of elements for systematic reviews and meta-analyses (PRISMA). The PICO method was used to structure the important components of the research questions. The results of this review showed that there is currently little application of Cleaner Production in drinking water systems. This article concludes that Cleaner Production is a strategy that contributes to reducing the environmental impact generated by the different activities of treatment and distribution of drinking water. However, it is necessary to carry out research that promotes the dissemination and knowledge of the different Cleaner Production strategies, as well as highlighting the social, environmental, and economic benefits that their application could generate. Future research should aim at the application of Cleaner Production strategies such as water recycling and Good Housekeeping. Technological progress in purification processes can offer promising results for saving water, energy, waste reduction, and gaseous emissions.

This study evaluated the impact of land use/land cover patterns on the water quality of a stream in a periurban zone. For this, the water quality was determined by the NSF-WQI, Dinius-WQI, and Heavy Metal Pollution Index (HPI). On the other hand, land uses were obtained from “RapidEye” satellite images, including green, urban, commercial and industrial areas. The land uses were grouped, and the different degrees of association with the chosen water quality parameters were found. The results indicated that the physicochemical parameters were negatively correlated with the “green areas” and positively correlated with the “intervened areas”.

This study assessed a high Andean lake's trophic state and water quality using methodologies with eutrophication and water quality indexes. Water samples were collected at six points in the lake, with a monthly frequency, for three winter and three summer months. Dissolved oxygen, pH, phosphates, nitrates, transparency, chlorophyll-a, fecal coliforms, biological oxygen demand (BOD), temperature, and turbidity were determined at each point. The trophic state of the lake was categorized by applying the Organization for Economic Cooperation and Development (OECD) eutrophication index, Carlson's trophic state index (CTSI) and trophic index (TRIX). In addition, National Sanitation Foundation water quality index (NSF-WQI), Canadian Water Quality Index (CCME-WQI) and Oregon Water Quality Index (OWQI) were used to evaluate water quality. Results indicated that the lake had a high level of eutrophication, suggesting an excessive accumulation of nutrients in the water. CTSI and TRIX index showed that the lake was in a hyper-eutrophic state, while according to the OECD methodology, the trophic state related to phosphorus and transparency was hypereutrophic, and according to chlorophyll, it varied from mesotrophic to eutrophic. The NSF index classified the lake with average quality, the CCME index indicated fair water quality, and the OWQI classified it as very poor. Therefore, the water quality of the high andean lake assessed by eutrophication and water quality indexes presented significant differences based on physicochemical characteristics. The human influence was identified as the main cause of eutrophication, including tourism and agriculture. These results suggest that measures should be taken to reduce human activity in the area and control pollution in the lake.

Predictive mathematical models were developed for removing Chemical Oxygen Demand (COD) and Total Suspended Solids (TSS) and optimizing the main operating parameters of the Fenton process, applied to effluents from a fish canning industry. The maximum removals obtained for COD and TSS were 89.2 % and 76.1 %, respectively. The optimum doses for COD removal were: 200 mg/L FeSO4 7H2O and 1,000 mg/L H2O2 at pH 2.5. While for TSS removal the optimum parameters were 1 200 mg/L H2O2, 300 mg/L FeSO4 7H2O, and pH 3. The adjusted R2 values of the COD and TSS removal models were 70.64 % and 98.01 %, respectively, indicating that the models obtained are acceptable in the prediction of both parameters.

En esta investigación se evaluó la cinética de reducción de la turbidez inicial (1455 UNT) de aguas residuales de una industria curtiembre mediante la aplicación de biofloculantes directos elaborados a partir del alga Chondracanthus chamissoi (alginato) y de las mudas del crustáceo Emerita analoga (quitosano). Se recolecto el material biológico precursor en las playas de Lima, Perú, a partir de este material; se produjo ácido algínico fibroso y posteriormente alginato de sodio. Se usaron los procesos de desmineralización, desproteinización y posterior desacetilación para obtener el quitosano a partir de las mudas del crustáceo. Se evaluó el efecto del pH, la dosis de los biofloculantes, el tiempo de equilibrio del proceso. Además, se determinó el orden cinético de la velocidad de floculación mediante la prueba de jarras. Los resultados indicaron una remoción de la turbidez superior al 99 % dentro de los primeros 30 minutos para dosis de 0.2 a 2 g/l de floculantes y pH ácido (igual a 4); no se registraron diferencias significativas a distintos valores de pH (4-12) y dosis (0.2 a 2 g/l). El ajuste lineal entre el tiempo de floculación y la turbidez generó ecuaciones cinéticas significativas de primer orden para ambos floculantes con constantes de velocidad k1 del orden de 10-4 (1/NUT.min) y tiempos de reducción de la mitad de material particulado (vida media: τ1/2) inferiores a los 10 minutos. Esto se puede considerar como un criterio para medir la eficiencia del proceso de floculación directa en el tratamiento de aguas industriales de curtiembre.

Abstract A total of 188,859 meteorological-PM $$_{10}$$ 10 data validated before (2019) and during the COVID-19 pandemic (2020) were used. In order to predict PM $$_{10}$$ 10 in two districts of South Lima in Peru, hourly, daily, monthly and seasonal variations of the data were analyzed. Principal Component Analysis (PCA) and linear/nonlinear modeling were applied. The results showed the highest annual average PM $$_{10}$$ 10 for San Juan de Miraflores (SJM) (PM $$_{10}$$ 10 -SJM: 78.7 $$\upmu$$ μ g/m $$^{3}$$ 3 ) and the lowest in Santiago de Surco (SS) (PM $$_{10}$$ 10 -SS: 40.2 $$\upmu$$ μ g/m $$^{3}$$ 3 ). The PCA showed the influence of relative humidity (RH)-atmospheric pressure (AP)-temperature (T)/dew point (DP)-wind speed (WS)-wind direction (WD) combinations. Cool months with higher humidity and atmospheric instability decreased PM $$_{10}$$ 10 values in SJM and warm months increased it, favored by thermal inversion (TI). Dust resuspension, vehicular transport and stationary sources contributed more PM $$_{10}$$ 10 at peak times in the morning and evening. The Multiple linear regression (MLR) showed the best correlation (r = 0.6166), followed by the three-dimensional model LogAP-LogWD-LogPM $$_{10}$$ 10 (r = 0.5753); the RMSE-MLR (12.92) exceeded that found in the 3D models (RMSE $$

This article aimed to carry out a systematic review of rainwater harvesting and storage systems (RWHSS) between 2012 and 2022. This study used the guidelines of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement (PRISMA) as reviewing method. The systematic review process involved four stages: identification, screening, eligibility and inclusion. To carry out this research, the Scopus, ScienceDirect and Springer Link digital databases were consulted using the keywords “rainwater”, “storage”, “harvesting”, “rural”, “treatment”; initially obtaining 581 results, after filtering the information through PRISMA, 15 articles were obtained to carry out the analysis of the results linked to the questions raised in this work. The results showed that all the RWHSS have four main components: 1) Catchment area, 2) gutters, 3) pipes and 4) storage system. Regarding the most used material in the system's catchment area, it is galvanized metal with 25.71% of the studies and for the construction of the cistern, it is concrete with 41.66%. The quality of the rainwater collected in the RWHSS varies according to some factors such as the material, maintenance, weather conditions, etc. The main rainwater quality parameters considered by the authors at the time of implementing and using an RWHSS were identified, and compliance of the parameters with the WHO standard values was also evaluated. The main parameters considered by the authors were: pH (66.66%), turbidity (53.33%), E. Coli (53.33%), lead (40%) and nitrates (40%).

The current research aims to investigate the treatment of real chrome tanning effluent by continuing electrocoagulation (EC) with electrodes of aluminum (anode) and iron (cathode). Also, the kinetic study and the effect of current density and operating time on Cr (VI), turbidity, and chemical oxygen demand (COD) removal efficiency were evaluated. The results show that maximum removal efficiency of 84.7 % for Cr (VI), 88.7 % for turbidity and 81.0 % for COD occurred at a current density of 679.3 A /m2. The maximum turbidity removal value was reached after 15 minutes of operation, while it took 20 minutes to remove the maximum value of Cr (VI) and COD at pH 3.5. The kinetic data were fitted to the pseudo second order model for COD and the pseudo first order for Cr (VI) showing a higher removal rate of Cr than COD. The estimated operating cost was USD 2.74/m3 of effluent. This value only included anode material and energy consumption costs.

The present study aims to optimize the application of a microbial fuel cell (MFC) in the treatment of slaughterhouse wastewater and the production of electricity. The methodology included the response surface analysis (RSA) to evaluate the effect of three factors: the standard reduction potential, SRP (copper, zinc, and graphite; electrode surface area (ESA), and the doses of ruminal liquor (DOSE). The power density (PD) and the removal of the chemical oxygen demand (COD) were determined as the main response variables. The results indicated that the generation of electrical energy depended significantly on the SRP applied, highlighting the copper-graphite arrangement that generated a maximum PD (0.5685 W/m3) and the graphite-graphite that produced the highest removal of COD (81.33%). Consequently, the RSA produced significant predictive models for the generation of PD (R2 = 0.9485, p = 0.029) and removal of COD (R2 = 0.9888, p = 0.002). MFC is presented as a technology intended to be part of the diversification of renewable energy sources and at the same time recover water resources sustainably.

El uso de enmiendas orgánicas mejora la calidad y aumenta la fertilidad de los suelos debido a sus propiedades de adsorción, estimula el ciclo de nutrientes y puede usarse para reducir la disponibilidad de metales pesados. El principal objetivo de la investigación fue evaluar el efecto del biocarbón (BC) derivado de las excretas porcinas sobre la disponibilidad de Pb en un suelo agrícola contaminado y encalado. Se aplicó un diseño experimental aleatorizado, las excretas de cerdo se secaron a temperatura ambiente (23 °C) y se pirolizaron a 500 °C durante 2 h. Se aplicaron dosis del 5%, 10% y 20% de BC a los suelos contaminados con Pb (165,7 mg/kg), que se dispusieron en macetas de 2 kg con excepción de la muestra control, y posteriormente se cultivó Lactuca sativa para evaluar la disponibilidad de Pb. Los resultados indicaron una mejora en la calidad del suelo a dosis más altas de BC, aumento de 0,34 unidades de pH, disminución de Pb extraído por EDTA (27% a 62% de disminución) y contenido no significativo de Pb en lixiviados (< 1 mg Pb/L) y sin detección en raíces de plantas (< 0,01 mg/kg), excepto para la planta de control (0,7 mg Pb/kg) en el suelo original. Se obtuvo un modelo relacional logarítmico entre la dosis de BC y el Pb adsorbido en el suelo (R2 = 0,9938, p < 0,05) que muestra que la disminución de la disponibilidad de Pb en el suelo aumentó para dosis más altas de BC, lo que representa una alternativa de remediación ecológica. Se recomienda investigar las relaciones de interacción entre los parámetros de calidad del suelo y establecer modelos funcionales de bioacumulación y metal extraíble del suelo enmendado.

Cleaner Production (CP) has been studied mainly in the productive sector, ignoring that in drinking water treatment plants (DWTP) a better environmental performance can be achieved. The objective of this study was to evaluate the processes in a DWTP in order to improve production, reduce environmental impact and generate economic savings, for which a cleaner production plan was implementing. The methodology recommended by UNIDO was used. Three CP opportunities were evaluated and identified. After, each CP opportunity, a technical, environmental and economic feasibility analysis was carried out. The results indicated that by implementing the first opportunity of CP (Good housekeeping), it will save water by reducing the number of filter washes by 29400 m3/year, without any investment, so the gains will be immediate. With the second chance of CP, a water-saving of 23256 m3/year will be achieved by recirculating the water from the filters to the decanters. The investment is small, and the recovery period will be 2.4 months. The third CP option, which is based on the coagulant change, would have an annual financial savings of 5361.12 USD, with an immediate payback period. The results showed that the CP applications proposed in this study can significantly reduce water consumption in a WDTP, being able to be implemented in the short and medium-term, without large investments, allowing to address water scarcity today and in the future.

This review goal is to reflect on the challenges and prospects for water quality in the face of the pandemic caused by the new SARS-CoV-2 coronavirus (COVID-19). Based on the information available so far, the detection of SARS-CoV-2 RNA in wastewater has raised interest in using it as an early warning method, to detect the resurgence of infections and to report the risk associated with contracting SARS-CoV-2 in contact with untreated water or inadequately treated wastewater is discharged. The wastewater-based epidemiological approach can be used as an early indicator of infection within a specific population. On the other hand, it is necessary to collect information from the managers of drinking water supply companies and professionals who are related to water quality, to know SARS-CoV-2 data and information, and its influence on drinking water quality. The basic purpose of this review article is to try to provide a valuable and quick reference guide to COVID-19. Important topics were discussed, such as detection of SARS-CoV-2 in wastewater in various parts of the world; wastewater screening to monitor COVID-19; persistence of SARS-CoV-2 in aquatic systems; the presence of SARS-CoV-2 in drinking water; clean water as a mechanism to deal with the COVID-19 pandemic; chlorine as a disinfectant to eliminate SARS-CoV-2 and damage to ecosystems by the use of chlorine. Currently does not exist extensive literature on the effectiveness of water and wastewater treatment processes that ensure the correct elimination of SARS-CoV-2. Excessive use of disinfectants such as chlorine is causing effects on the environment. This document highlights the need for further research to establish the behavior of the SARS-CoV-2 virus in aquatic systems. This study presents an early overview of the observed and potential impacts of COVID-19 on the environment.