Centrality evolution of the charged-particle pseudorapidity density over a broad pseudorapidity range in Pb-Pb collisions at root s(NN)=2.76TeV

Peer reviewe

Primary Treatment of Domestic Wastewater with the Use of Unmodified and Chemically Modified Drinking Water Treatment Sludge

Improved wastewater (WW) treatment contributes to preserving human life and aquatic ecosystems and acting on climate change. The use of drinking water treatment sludges (WTS) as coagulants in the primary treatment of WW contributes, in this regard, and simultaneously enables the sustainable management of this waste. In this work, the improvement of the primary treatment of real domestic WW using unmodified WTS and chemically modified WTS with sulphuric and hydrochloric acids (reactive sludges—RSs) as coagulants was evaluated. The evaluated WTS contains a higher fraction of inorganic solids and is mainly an amorphous material. The wet WTS (W-WTS) showed a better performance in enhancing WW clarification (up to 76%), as measured by turbidity in comparison with the dry WTS (D-WTS). All RSs improved this performance considerably (up to 98%), and of these, the sulphuric reactive sludge generated from the W-WTS (SRS-W) showed the lowest costs associated with acid consumption for activation. The best treatments with W-WTS and SRS-W significantly improved the removal of solids (total suspended solids > 90% and volatile suspended solids > 80%), organic matter (total biochemical oxygen demand > 50% and total chemical oxygen demand > 55%), and total phosphorus (>75%) compared to natural sedimentation, with slight differences in favour of SRS-W, especially in the removal of phosphorus species. The reuse of WTSs in primary WW treatment becomes a valuable circular economy proposal in the water sector, which simultaneously valorises waste from the drinking water process and contributes to the fulfilment of Sustainable Development Goal 6 (Clean Water and Sanitation

Primary Treatment of Domestic Wastewater with the Use of Unmodified and Chemically Modified Drinking Water Treatment Sludge

Improved wastewater (WW) treatment contributes to preserving human life and aquatic ecosystems and acting on climate change. The use of drinking water treatment sludges (WTS) as coagulants in the primary treatment of WW contributes, in this regard, and simultaneously enables the sustainable management of this waste. In this work, the improvement of the primary treatment of real domestic WW using unmodified WTS and chemically modified WTS with sulphuric and hydrochloric acids (reactive sludges—RSs) as coagulants was evaluated. The evaluated WTS contains a higher fraction of inorganic solids and is mainly an amorphous material. The wet WTS (W-WTS) showed a better performance in enhancing WW clarification (up to 76%), as measured by turbidity in comparison with the dry WTS (D-WTS). All RSs improved this performance considerably (up to 98%), and of these, the sulphuric reactive sludge generated from the W-WTS (SRS-W) showed the lowest costs associated with acid consumption for activation. The best treatments with W-WTS and SRS-W significantly improved the removal of solids (total suspended solids > 90% and volatile suspended solids > 80%), organic matter (total biochemical oxygen demand > 50% and total chemical oxygen demand > 55%), and total phosphorus (>75%) compared to natural sedimentation, with slight differences in favour of SRS-W, especially in the removal of phosphorus species. The reuse of WTSs in primary WW treatment becomes a valuable circular economy proposal in the water sector, which simultaneously valorises waste from the drinking water process and contributes to the fulfilment of Sustainable Development Goal 6 (Clean Water and Sanitation

Assessment of a clarifier sludge blanket at laboratory scale

En este artículo se reportan los resultados de la operación y evaluación de un clarificador de manto de lodos de suspensión hidráulica a escala de laboratorio a partir de un diseño de experimentos factorial 23, en el cual se utilizaron la turbiedad del agua cruda, la carga hidráulica o tasa superficial y el tipo de coagulante como factores que podían afectar la formación del manto y, por consiguiente, la eficiencia del sistema en la remoción de la turbiedad del agua. Se emplearon dos tipos de coagulante: sulfato de aluminio y C-235 (polímero catiónico) y se estudiaron dos diferentes tipos de agua cruda (sintética) preparadas en el laboratorio con la adición de caolín, la primera con alta turbiedad (Tipo I con 100 UNT) y la segunda con baja turbiedad (Tipo II con 15 UNT). El sistema fue operado con tasas superficiales de 35 y 70 m3/m2.día. Los resultados obtenidos permiten establecer que cuando el sistema se operó con agua Tipo I y una carga hidráulica de 70 m3/m2.día se generó el manto de mejores características y la turbiedad en el efluente alcanzó valores por debajo de 2 UNT.In this paper, we report the results for the operation and performance of a laboratory-scale clarifier sludge blanket suspension hydraulic, through a series of experiments that used a 23 factorial design. Factors in the design included: turbidity of raw water, hydraulic load rate and type of coagulant. These factors could affect the formation of a blanket, and therefore, the system’s efficiency on the removing turbidity. Two types of coagulants –aluminum sulfate and C-325 (a cationic polymer)– were tested in two types of synthetic raw water prepared in the laboratory through the addition of kaolin with high (Type I with 100 NTU) and low (Type II with 15 NTU) turbidity. The system was operated with surface load rates of 30 and 70 m3/m2.day. Results show that the best blanket was generated when the system was operated with Type I water and a hydraulic load rate of 70 m3/ m2.day, with turbidity values in the effluent below 2 NTU

A Coagulation Process Combined with a Multi-Stage Filtration System for Drinking Water Treatment: An Alternative for Small Communities

As set out in the Sustainable Development Goals, it is necessary to achieve universal and equitable access to safe drinking water services for all the world’s population. Appropriate water treatment alternatives for rural areas should be prioritised to achieve this goal. In this work, a simplified drinking water treatment system (SDWTS), which has great potential for application in small communities and rural areas, was evaluated on a pilot scale for turbidity and apparent colour removal using synthetic raw water. The SDWTS integrates Upflow Gravel Filter in Layers (UGFL) and Rapid Sand Filter (RSF) with previous coagulation. This evaluation was carried out using a 23 factorial experiment, with the factors: type of water, type of coagulant and flow. The factorial design showed that the SDWTS had the highest turbidity removal efficiencies (>98.7%) with type II (20 NTU) water and PACl coagulant, while flow rate had no significant effect on turbidity removal. Under optimal operating conditions (type II water, PACl and 1.0 m3/d), the SDWTS produces treated water that meets the standards required by Colombian regulations and World Health Organisation recommendations for drinking water, concerning the variables: turbidity, apparent colour, total coliforms, E. coli, pH, electrical conductivity and Al. The SDWTS maintained its capacity to produce potable water when evaluated with the increased operating flow (up to 3.0 m3/d) and raw water turbidity (up to 50 NTU). The SDWTS can be an efficient and innovative alternative for water treatment, and its implementation in small communities can contribute to equitable access to drinking water

A Coagulation Process Combined with a Multi-Stage Filtration System for Drinking Water Treatment: An Alternative for Small Communities

As set out in the Sustainable Development Goals, it is necessary to achieve universal and equitable access to safe drinking water services for all the world’s population. Appropriate water treatment alternatives for rural areas should be prioritised to achieve this goal. In this work, a simplified drinking water treatment system (SDWTS), which has great potential for application in small communities and rural areas, was evaluated on a pilot scale for turbidity and apparent colour removal using synthetic raw water. The SDWTS integrates Upflow Gravel Filter in Layers (UGFL) and Rapid Sand Filter (RSF) with previous coagulation. This evaluation was carried out using a 23 factorial experiment, with the factors: type of water, type of coagulant and flow. The factorial design showed that the SDWTS had the highest turbidity removal efficiencies (>98.7%) with type II (20 NTU) water and PACl coagulant, while flow rate had no significant effect on turbidity removal. Under optimal operating conditions (type II water, PACl and 1.0 m3/d), the SDWTS produces treated water that meets the standards required by Colombian regulations and World Health Organisation recommendations for drinking water, concerning the variables: turbidity, apparent colour, total coliforms, E. coli, pH, electrical conductivity and Al. The SDWTS maintained its capacity to produce potable water when evaluated with the increased operating flow (up to 3.0 m3/d) and raw water turbidity (up to 50 NTU). The SDWTS can be an efficient and innovative alternative for water treatment, and its implementation in small communities can contribute to equitable access to drinking water

Control of fasciola hepatica in animal drinking water by fast and slow filtration

La fasciolosis bovina es una zoonosis causada por Fasciola hepatica, parásito que se adquiere al consumir agua o vegetales contaminados con el digeneo. Esta enfermedad ocasiona pérdidas económicas importantes en las regiones lecheras de Antioquia. En este trabajo, y con el objetivo de remover los huevos del parásito presentes en el agua, se diseñaron y construyeron dos filtros empleando como lecho filtrante arena industrial (T.E entre 0,45 y 0,55 mm), con los cuales se evaluó un sistema de filtración rápida operado a velocidades de 5 y 8 m/h (altura del lecho 60 cm) y un sistema de filtración lenta a una velocidad de 1,46 m/h (alturas del lecho 30 y 40 cm). Se determinó la variación del caudal y la turbiedad del efluente durante la carrera de filtración y la eficiencia de remoción de los huevos del parásito. Los filtros operando bajo las características descritas, fueron 100% eficientes para remover los huevos de F. hepatica presentes en el agua. Los porcentajes de remoción de turbiedad fueron del 85,5 y 79,4% para filtros trabajando a velocidades de 5 m/h y 8 m/h, respectivamente.The bovine fasciolosis is a zoonosis caused by Fasciola hepatica transmitted by consuming water and / or vegetables contaminated with the digenea. This disease causes significant economic losses in the dairy producer regions of Antioquia. In order to remove the eggs of the parasite from water, we designed and built two filters (rapid and slow filtration), using industrial sand as filter bed (effective size 0.45-0.55 mm). A rapid filtration system was evaluated at speeds of 5 and 8 m/h for a sand bed height of 60 cm and a slow filtration system at a speed of 1.46 m/h for sand bed heights of 30 and 40 cm. The variation of effluent flow and removal efficiency of both turbidity and parasite eggs were determined during the run of each filtration. The results show that all filters operating under the described features are 100% efficient in removing the F. hepatica eggs from the water. The turbidity removal percentages were 85.5% and 79.4% for filters operating at speeds of 5 m/h and 8 m/h respectively

Revista Temas Agrarios Volumen 26; Suplemento 1 de 2021

1st International and 2nd National Symposium of Agronomic Sciences: The rebirth of the scientific discussion space for the Colombian Agro.1 Simposio Intenacional y 2 Nacional de Ciencias Agronómicas: El renacer del espacio de discusión científica para el Agro colombiano