Records with Keyword: Wastewater
Showing records 1 to 25 of 76. [First] Page: 1 2 3 4 Last
Fenton: A Systematic Review of Its Application in Wastewater Treatment
Matheus Pimentel Prates, Suzana Maria de Oliveira Loures Marcionílio, Karine Borges Machado, Danyelle Medeiros de Araújo, Carlos A. Martínez-Huitle, Arizeu Luiz Leão Arantes, José Eduardo Ferreira da Silva Gadêlha
January 5, 2024 (v1)
Subject: Environment
Keywords: advanced oxidative processes, pollution, scientometrics, Wastewater
The use of new technologies for the removal of pollutants from wastewater has become globally necessary due to the complexity and facilities defined by conventional treatments. Advanced oxidative processes, specifically the Fenton process, have become widely applied given their low cost and ease of use. Therefore, this study aimed to evaluate the progression of the scientific publications on the implementation of Fenton process, investigating their space−time evolution. Additionally, useful solutions, trends, and gaps in the applications for the removal of pollutants with this methodology were identified, and also different remediation strategies and the design of new treatments for wastewaters were identified within this scientometric analysis. Bibliometric research was conducted in two scientific databases, Web of Science and Scopus, from 2011 to 2022, and we identified 932 and 1263 studies with the word “Fenton,” respectively. When these publications are associated with the treatmen... [more]
Advancement in Microbial Fuel Cells Technology by Using Waste Extract as an Organic Substrate to Produce Energy with Metal Removal
Ghada Mohamed Aleid, Anoud Saud Alshammari, Alamri Rahmah Dhahawi Ahmad, Fida Hussain, Sang-Eun Oh, Akil Ahmad, Mohamad Nasir Mohamad Ibrahim, Khalid Umar
September 21, 2023 (v1)
Subject: Biosystems
Keywords: Energy, heavy metals, microbial fuel cell, organic substrate, Wastewater
Energy generation using microbial fuel cells (MFC) and removing toxic metal ions is a potentially exciting new field of study as it has recently attracted a lot of interest in the scientific community. However, MFC technology is facing several challenges, including electron production and transportation. Therefore, the present work focuses on enhancing electron generation by extracting sugarcane waste. MFC was successfully operated in a batch mode for 79 days in the presence of 250 mg/L Pb2+ and Hg2+ ions. Sugarcane extract was regularly fed to it without interruption. On day 38, the maximum current density and power density were recorded, which were 86.84 mA/m2 and 3.89 mW/m2, respectively. The electrochemical data show that a sufficient voltage generation and biofilm formation produce gradually. The specific capacitance was found to be 11 × 10−4 F/g on day 79, indicating the steady growth of biofilm. On the other hand, Pb2+ and Hg2+ removal efficiencies were found to be 82% and 74.85... [more]
Dyes and Heavy Metals Removal from Aqueous Solutions Using Raw and Modified Diatomite
Simona Gabriela Muntean, Maria Andreea Nistor, Raisa Nastas, Oleg Petuhov
September 20, 2023 (v1)
Subject: Environment
Keywords: Adsorption, equilibrium, kinetic, pollutant, Wastewater
The progress of the textile industry has led to a severe increase in the discharge of colored effluents, polluted with dyes and metal ions (non-biodegradable, carcinogenic to humans and environmental hazards). The implementation of effective methodologies and materials for the treatment of wastewater has become an urgent requirement. The present work describes the application of two samples of mineral materials—Ghidirim diatomite and modified diatomite—as adsorbents for the removal of dyes—Acid Blue 350, Methylene Blue, Basic Red 2—and of metal ions—copper, zinc, and lead—from aqueous solutions. In order to determine the optimal working conditions by which to ensure maximum removal efficiency, the influence of the nature and amount of the sorbent, the initial concentration of pollutant, and the temperature were studied. Working under normal conditions (room temperature, solution pH) efficiencies greater than 80% were obtained for the removal of dyes and metal ions. The adsorption fitte... [more]
Chitosan Glutaraldegyde Cryogels for Wastewater Treatment and Extraction of Silver Nanoparticles
Dmitriy Berillo, Aknazar Arysbek
July 4, 2023 (v1)
Subject: Materials
Keywords: chitosan, cryogels, Freundlich adsorption isotherm, Langmuir adsorption isotherm, nanoparticles, Wastewater
The discharge of nanoparticles into the environment, such as through industrial plants and municipal wastewater treatment plants, can pose a hazard to aquatic life. This study demonstrates the effective removal of silver nanoparticles (AgNPs) using a chitosan-based cryogel, which has potential applications in agriculture, as well as in water treatment or in industrial plants that discharge into environmentally sensitive water bodies. The adsorbent is economically viable, has high affinity toward metal nanoparticles, is biodegradable and biocompatible, and displays a good removal of nanoparticles. AgNP adsorption was monitored using UV/Vis spectroscopy and TEM analysis. SEM, nitrogen adsorption, TGA, and FTIR analysis were used for cryogel characterization. The BET model of nitrogen adsorption revealed a specific surface area of 7.7 m2/g for chitosan−glutaraldehyde (CHI−GA) cryogels. The elasticity modulus of the CHI−GA cryogel was estimated as 543 ± 54 kPa. The AgNPs were characterized... [more]
Efficient Degradation of Chlortetracycline by Graphene Supported Cobalt Oxide Activated Peroxydisulfate: Performances and Mechanisms
Wei Li, Bin Yao, Yuguo Zheng, Guiqiang Zhang, Dan Zhi, Yaoyu Zhou
June 7, 2023 (v1)
Subject: Environment
Keywords: advanced oxidation processes (AOPs), antibiotic, cobalt oxide, reduced graphene oxide, Wastewater
Cobalt oxide has good catalytic activity for peroxydisulfate (PDS) activation but poor stability and is vulnerable to inactivation because of agglomeration. In this work, the chlortetracycline (CTC) degradation by peroxydisulfate (PDS) catalysis using the reduced graphene oxide support cobalt oxide (Co3O4/rGO) composite catalyst was investigated. It was found that 86.3% of CTC was degraded within 120 min in the Co3O4/rGO-800/PDS system. The influences of catalyst dosage, PDS concentration, solution pH, and reaction temperature were systematically explored. The excellent removal performance of CTC could be attributed to the synergistic effect between adsorption and catalytic degradation. ≡Co2+ and surface functional groups played as active sites to catalyze PDS, and the circulation of ≡Co2+/≡Co3+ was achieved. Moreover, Co3O4/rGO-800 showed satisfactory reusability after three cycles. This research can provide useful information for the development of efficient PDS catalysts and facilit... [more]
Circular Economy in Wastewater Treatment Plant—Water, Energy and Raw Materials Recovery
Marzena Smol
May 24, 2023 (v1)
Subject: Materials
Keywords: CE, circular economy, Energy, phosphorus, raw materials, Wastewater, wastewater treatment plant, Water, WWTP
Nowadays, the main challenge for industrial and municipal enterprises is related to the tightening regulations and recommendations regarding environmental protection, which have been included in the circular economy (CE) package. Enterprises from all sectors, including water and sewage management, are obliged to actively participate in the CE transition. Modern wastewater treatment plants (WWTPs) should include actions aimed at a more sustainable use of available resources (water, energy, raw materials) to contribute to the protection of natural resources. In this way, they can be treated as resource facilities. This paper proposes a conceptual framework for a ‘Wastewater Treatment Plant of the Future’ that includes several technological solutions that take into account circular management of waste streams generated in WWTPs, such as wastewater (WW), sewage sludge (SS) and sewage sludge ash (SSA). Many actions have been already taken to modernize and build WWTPs that can respond to cur... [more]
Bibliometric Analysis of Constructed Wetlands with Ornamental Flowering Plants: The Importance of Green Technology
José Luis Marín-Muñiz, Irma Zitácuaro-Contreras, Gonzalo Ortega-Pineda, Luis Manuel Álvarez-Hernández, Karina Elizabeth Martínez-Aguilar, Aarón López-Roldán, Sergio Zamora
April 28, 2023 (v1)
Subject: Environment
Keywords: bibliometric study, ornamental plants, treatment wetlands, Wastewater
The use of constructed wetlands (CWs) for wastewater treatment has earned high interest around the world. However, innovations to improve its removal efficiency and adoption have been suggested in the last decades. For instance, the use of ornamental flowering plants (OFP), which make wetland treatment systems more aesthetic and is an option for the production of commercial flowers while the water is cleansed. The objectives of this study were to identify through a bibliometric analysis (2000−2022) the main OFP that have been used in CWs and their functionality as phytoremediators (removal effects), as well as the authors, collaborations, main investigations, and the countries where such investigations have been carried out. To this respect, 10,254 studies on CWs were identified. The United States and China were the leading countries in the use of this eco-technology. Subsequently, regarding the use of OFP, the analysis revealed 92 studies on this matter in which Mexico has three resea... [more]
Mathematical Modeling of Microbial Electrolysis Cells for Enhanced Urban Wastewater Treatment and Hydrogen Generation
Narges Rahimi, Ursula Eicker
April 28, 2023 (v1)
Keywords: Hydrogen, microbial electrolysis cell, Modelling, Wastewater
Conventional wastewater treatment plants (CWTPs) are intensive energy consumers. New technologies are emerging for wastewater treatment such as microbial electrolysis cells (MECs) that can simultaneously treat wastewater and generate hydrogen as a renewable energy source. Mathematical modeling of single and dual-chamber microbial electrolysis cells (SMEC and DMEC) has been developed based on microbial population growth in this study. The model outputs were validated successfully with previous works, and are then used for comparisons between the SMEC and DMEC regarding the hydrogen production rate (HPR). The results reveal that the daily HPR in DMEC is higher than in SMEC, with about 0.86 l H2 and 0.52 l H2, respectively, per 1 L of wastewater. Moreover, the results have been used to compare the HPR in water electrolysis (WE) processes and MECs. WE consume 51 kWh to generate 1 kg of hydrogen, while SMEC and DMEC require only 30 kWh and 24.5 kWh, respectively.
Primary Research of a New Zero-Liquid-Discharge Technology of Wet Flue Gas Desulfurization Wastewater by Low-Rank Heat from Flue Gas
Xuan Yao, Man Zhang, Boyu Deng, Xinhua Yang, Hairui Yang
April 21, 2023 (v1)
Subject: Environment
Keywords: concentrate, flue gas waste heat, Wastewater, WFGD, zero liquid discharge (ZLD)
Wet flue gas desulfurization (WFGD) wastewater treatment is a key problem in coal-fired plants. Traditional chemical precipitation methods cannot reach zero-liquid discharge (ZLD). In this paper, a new technology using the low-rank heat from flue gas to concentrate the wastewater for ZLD is proposed. A scrubber was built to verify the concentrating process, and the characteristics of the concentrated water were analyzed. The concentrated water was neutralized by adding Ca(OH)2 to raise the pH value. The wastewater can be concentrated 10~25 times to reduce the flow rate. The characteristics of the concentrated wastewater were studied by dosing lime. Then, liquid and solids were separated by filter pressing, the liquid was mainly composed of CaCl2, which accounts for 73.6%. The sludge is composed of CaSO4 and Mg(OH)2, depending on the lime consumption of the dosing process. Finally, the filter liquor after the filter press was mixed with ash to reach zero liquid discharge, and the sludge... [more]
Economic Considerations on Nutrient Utilization in Wastewater Management
Josef Maroušek, Anna Maroušková
April 20, 2023 (v1)
Keywords: algae biomass, biofuel, Biomass, Spirulina platensis, Wastewater, wastewater treatment
There is wide consensus that Spirulina can serve as a tool for wastewater management and simultaneously provide feedstock for biorefining. However, the economic aspects associated with its use remain a significant challenge. Spirulina cultivated in wastewater decreased the concentrations of both ammonia and nitrate and also served as a biodiesel source. The oil obtained in the feedstock was subjected to transesterification and turned into biodiesel. The biodiesel was subsequently analyzed in a test motor (water-cooled, four-stroke, single-cylinder compression ignition with injection). The tests were conducted at a constant 1500 rpm, and the output power was 3.7 kW. Mixtures of diesel and biodiesel were also enriched with carbon nanotubes (CNTs). The amount of CNTs added to the diesel was 30 mg L−1. The algae and de-oiled biomass were characterized using XRD analysis, and an ultrasonicator was used to mix the CNTs with diesel and spirulina blends. A series of tests were conducted at dif... [more]
Co-Management of Sewage Sludge and Other Organic Wastes: A Scandinavian Case Study
Clara Fernando-Foncillas, Maria M. Estevez, Hinrich Uellendahl, Cristiano Varrone
April 20, 2023 (v1)
Keywords: anaerobic digestion, biorefinery, co-digestion, organic waste, resource recovery, sewage sludge, waste management, Wastewater
Wastewater and sewage sludge contain organic matter that can be valorized through conversion into energy and/or green chemicals. Moreover, resource recovery from these wastes has become the new focus of wastewater management, to develop more sustainable processes in a circular economy approach. The aim of this review was to analyze current sewage sludge management systems in Scandinavia with respect to resource recovery, in combination with other organic wastes. As anaerobic digestion (AD) was found to be the common sludge treatment approach in Scandinavia, different available organic municipal and industrial wastes were identified and compared, to evaluate the potential for expanding the resource recovery by anaerobic co-digestion. Additionally, a full-scale case study of co-digestion, as strategy for optimization of the anaerobic digestion treatment, was presented for each country, together with advanced biorefinery approaches to wastewater treatment and resource recovery.
Impacts of Long- and Short-Term of Irrigation with Treated Wastewater and Synthetic Fertilizers on the Growth, Biomass, Heavy Metal Content, and Energy Traits of Three Potential Bioenergy Crops in Arid Regions
Mahmoud F. Seleiman, Nasser Al-Suhaibani, Salah El-Hendawy, Kamel Abdella, Majed Alotaibi, Ali Alderfasi
April 20, 2023 (v1)
Subject: Environment
Keywords: bioenergy crops, Biomass, heavy metals, synthetic fertilizer, Wastewater
The availability of suitable water is an important factor for increasing the cultivated areas and sustainability in arid (i.e., less than 200 mm precipitation per year) and semiarid regions (i.e., 200−700 mm precipitation per year). Therefore, this study aimed to analyze the impact of treated wastewater (TWW) and groundwater (GW) as well as synthetic fertilizers (50% and 100% of the recommended NPK dose; 150−150−60 kg N−P2O5−K2O ha−1) on the growth, biomass, energy traits, and macro and trace elements of maize (Zea mays L.), sorghum (Sorghum bicolor L.), and pearl millet (Pennisetum glaucum L) grown in old cultivated (first location; L1) and virgin soil (L2 and L3) as potential bioenergy crops. The soil in L1 has been irrigated with treated wastewater for the last 15 years and continued to be irrigated with treated wastewater in this investigation. The virgin soil was divided into two parts: the first part was irrigated with TWW, and the second part was irrigated with GW. The experimen... [more]
Immobilising Microalgae and Cyanobacteria as Biocomposites: New Opportunities to Intensify Algae Biotechnology and Bioprocessing
Gary S. Caldwell, Pichaya In-na, Rachel Hart, Elliot Sharp, Assia Stefanova, Matthew Pickersgill, Matthew Walker, Matthew Unthank, Justin Perry, Jonathan G. M. Lee
April 19, 2023 (v1)
Keywords: bioreactor, Carbon Capture, Carbon Dioxide, eutrophication, immobilization, latex polymers, Process Intensification, Wastewater
There is a groundswell of interest in applying phototrophic microorganisms, specifically microalgae and cyanobacteria, for biotechnology and ecosystem service applications. However, there are inherent challenges associated with conventional routes to their deployment (using ponds, raceways and photobioreactors) which are synonymous with suspension cultivation techniques. Cultivation as biofilms partly ameliorates these issues; however, based on the principles of process intensification, by taking a step beyond biofilms and exploiting nature inspired artificial cell immobilisation, new opportunities become available, particularly for applications requiring extensive deployment periods (e.g., carbon capture and wastewater bioremediation). We explore the rationale for, and approaches to immobilised cultivation, in particular the application of latex-based polymer immobilisation as living biocomposites. We discuss how biocomposites can be optimised at the design stage based on mass transfe... [more]
Techno-Cost-Benefit Analysis of Biogas Production from Industrial Cassava Starch Wastewater in Thailand for Optimal Utilization with Energy Storage
Chatree Wattanasilp, Roongrojana Songprakorp, Annop Nopharatana, Charoenchai Khompatraporn
April 13, 2023 (v1)
Keywords: biogas technology, cassava starch, Renewable and Sustainable Energy, storage, utilization pathway, Wastewater
This paper applied the optimization model of the biogas utilization pathway with the biogas utilization availability assessment to examine the effect of biogas system parameters on biogas utilization. The model analyzes the biogas utilization pathway availability and maximum profit to value added and productivity in biogas from industry wastewater in Thailand. The results showed that profit and availability of biogas utilization reduce biogas loss to flare, that it entails several conversion processes. The scenario for the biogas utilization pathway and storage with biogas production technology improves. Evaluated are operation time, waste and energy demand to the cassava starch usage during the production for 50−1000 tons per day. Five mature biogas production technologies were benchmarked evaluated based on the chemical oxygen demand removal efficiency and biogas yields. Subsequently, low-, medium-, and high-pressure storages and a battery storage were considered and discussed in thi... [more]
Life Cycle Assessment of Municipal Wastewater Treatment Processes Regarding Energy Production from the Sludge Line
Paulina Szulc, Jędrzej Kasprzak, Zbysław Dymaczewski, Przemysław Kurczewski
April 12, 2023 (v1)
Subject: Environment
Keywords: environmental effectiveness, environmental footprint, life cycle assessment, municipal wastewater treatment plant, Wastewater
The efficient and timely removal of organic matter and nutrients from water used in normal municipal functions is considered to be the main task of wastewater treatment plants (WWTPs). Therefore, these facilities are considered to be essential units that are required to avoid pollution of the water environment and decrease the possibility of triggering eutrophication. Even though these benefits are undeniable, they remain at odds with the high energy demand of wastewater treatment and sludge processes. As a consequence, WWTPs have various environmental impacts, which can be estimated and categorized using Life Cycle Assessment (LCA) analysis. In this study, a municipal WWTP based in Poznań, Poland, was examined using the method defined in ISO 14040. ReCiPe Endpoint and Midpoint (v1.11), in a hierarchical approach, were used to evaluate the environmental impacts regarding 18 different categories. All calculations were conducted using a detailed database from 2019, which describes each c... [more]
Water-Energy-Nutrients Synergies in the Agrifood Sector: A Circular Economy Framework
Efthymios Rodias, Eirini Aivazidou, Charisios Achillas, Dimitrios Aidonis, Dionysis Bochtis
April 12, 2023 (v1)
Keywords: agricultural waste, agrifood sector, bioeconomy, bioenergy, biofertilizers, circular economy, resource management, Wastewater, water reuse
Circular economy is emerging as a regenerative concept that minimizes emissions, relies on renewable energy, and eliminates waste based on the design of closed-loop systems and the reuse of materials and resources. The implementation of circular economy practices in resource-consuming agricultural systems is essential for reducing the environmental ramifications of the currently linear systems. As the renewable segment of circular economy, bioeconomy facilitates the production of renewable biological resources (i.e., biomass) that transform into nutrients, bio-based products, and bioenergy. The use of recycled agro-industrial wastewater in agricultural activities (e.g., irrigation) can further foster the circularity of the bio-based systems. In this context, this paper aims to provide a literature review in the field of circular economy for the agrifood sector to enhance resource efficiency by: (i) minimizing the use of natural resources (e.g., water, energy), (ii) decreasing the use o... [more]
Anaerobic Membrane Bioreactor (AnMBR) for the Removal of Dyes from Water and Wastewater: Progress, Challenges, and Future Perspectives
Amin Mojiri, John L. Zhou, Bahareh KarimiDermani, Elham Razmi, Norhafezah Kasmuri
April 11, 2023 (v1)
Subject: Environment
Keywords: AnMBR, biological methods, dyes, Wastewater
The presence of dyes in aquatic environments can have harmful effects on aquatic life, including inhibiting photosynthesis, decreasing dissolved oxygen levels, and altering the behavior and reproductive patterns of aquatic organisms. In the initial phase of this review study, our aim was to examine the categories and properties of dyes as well as the impact of their toxicity on aquatic environments. Azo, phthalocyanine, and xanthene are among the most frequently utilized dyes, almost 70−80% of used dyes, in industrial processes and have been identified as some of the most commonly occurring dyes in water bodies. Apart from that, the toxicity effects of dyes on aquatic ecosystems were discussed. Toxicity testing relies heavily on two key measures: the LC50 (half-lethal concentration) and EC50 (half-maximal effective concentration). In a recent study, microalgae exposed to Congo Red displayed a minimum EC50 of 4.8 mg/L, while fish exposed to Disperse Yellow 7 exhibited a minimum LC50 of... [more]
Efficiency of Coagulation/Flocculation for the Removal of Complex Mixture of Textile Fibers from Water
Sanja Vasiljević, Maja Vujić, Jasmina Agbaba, Stefania Federici, Serena Ducoli, Radivoj Tomić, Aleksandra Tubić
April 11, 2023 (v1)
Subject: Environment
Keywords: coagulation and flocculation, ferric chloride, polyaluminium chloride, removal of textile fibers, textile fibers, Wastewater
Synthetic fibers enter wastewater treatment plants together with natural fibers, which may affect treatment efficiency, a fact not considered in previous studies. Therefore, the aim of the present study was to evaluate the efficiency of the coagulation/flocculation process for the removal of a mixture of textile fibers from different water matrices. Natural and synthetic fibers (100 mg/L; cotton, polyacrylonitrile, and polyamide) were added to a synthetic matrix, surface water and laundry wastewater and subjected to coagulation/flocculation experiments with ferric chloride (FeCl3) and polyaluminum chloride (PACl) under laboratory conditions. In the synthetic matrix, both coagulants were found to be effective, with FeCl3 having a lesser advantage, removing textile fibers almost completely from the water (up to 99% at a concentration of 3.94 mM). In surface water, all dosages had approximately similar high values, with the coagulant resulting in complete removal. In laundry effluent, the... [more]
Recycled Smelter Slags for In Situ and Ex Situ Water and Wastewater Treatment—Current Knowledge and Opportunities
Saidur Rahman Chowdhury
April 11, 2023 (v1)
Subject: Environment
Keywords: adsorbent, recycling, smelter slags, treatment, Wastewater
Slags from the ferrous and nonferrous metallurgical industries have been used to treat toxic contaminants in water and wastewater. Using slag as a recycling or renewable resource rather than a waste product has environmental and economic benefits. Recycled smelter slags can be used in both in situ and ex situ treatment. However, their application has some limitations. One of the challenges is how to handle spent slag adsorbents, as they contain the accumulation of solid waste loaded with high concentrations of toxic contaminants. These challenges can be overcome by regeneration, recycling, reuse, and immobilization treatment of spent slag adsorbents. The present paper explored the scientific and technical information about the composition, reaction mechanisms, adsorption capacity, and opportunities of recycled slags while adsorbing toxic compounds from contaminated water. It comprehensively reviewed the current state of the art for using smelting slags as sustainable adsorbents for wat... [more]
Tequila Still Distillation Fractioned Residual Streams for Use in Biorefinery
Edgardo Martinez-Orozco, Pablo Gortares-Moroyoqui, Norberto Santiago-Olivares, Juan Napoles-Armenta, Ruth Gabriela Ulloa-Mercado, Celia De la Mora-Orozco, Luis Alonso Leyva-Soto, Luis Humberto Alvarez-Valencia, Edna Rosalba Meza-Escalante
April 11, 2023 (v1)
Subject: Environment
Keywords: agave bagasse, biorefinery, still distillation, tequila vinasses, Wastewater
Tequila vinasses is a mixture made from up to six still distillation two-stage process residual effluents. First stage fractions: residual must (60%), heads (0.9%) and tails (20.0%); second stage fractions: non-evaporated (8.0%), heads (0.1%) and tails (1.0%); the result is a more complex effluent for its treatment or biorefining. The objectives of this study were to: (a) characterize the five still distillation volatile streams in the Tequila 100% Agave processing; compounds: methanol, ethanol, acetaldehyde, ethyl acetate, sec-butanol, n-propanol, iso-butanol, n-butanol, iso-amyl, n-amyl, and ethyl lactate were detected by gas chromatography; calculated chemical oxygen demand from chemical composition had very high values (53,760−1,239,220 mg/L); measurement of pH (3.24−4.80), color (38.6 UC Pt-Co max), turbidity (46.1 max), electrical conductivity (3.30−172.20 μS/cm), and solid content (0 mg/L) was also made; (b) report an energy analysis (2.02 × 109 KWh) and CO2 production (429 × 10... [more]
Scaling-Up the Anaerobic Digestion of Pretreated Microalgal Biomass within a Water Resource Recovery Facility
Rubén Díez-Montero, Lucas Vassalle, Fabiana Passos, Antonio Ortiz, María Jesús García-Galán, Joan García, Ivet Ferrer
April 3, 2023 (v1)
Keywords: agricultural runoff, anaerobic digestion, biogas, biomethane, biorefinery, microalgae, photobioreactor, pretreatment, Wastewater
Microalgae-based wastewater treatment plants are low-cost alternatives for recovering nutrients from contaminated effluents through microalgal biomass, which may be subsequently processed into valuable bioproducts and bioenergy. Anaerobic digestion for biogas and biomethane production is the most straightforward and applicable technology for bioenergy recovery. However, pretreatment techniques may be needed to enhance the anaerobic biodegradability of microalgae. To date, very few full-scale systems have been put through, due to acknowledged bottlenecks such as low biomass concentration after conventional harvesting and inefficient processing into valuable products. The aim of this study was to evaluate the anaerobic digestion of pretreated microalgal biomass in a demonstration-scale microalgae biorefinery, and to compare the results obtained with previous research conducted at lab-scale, in order to assess the scalability of this bioprocess. In the lab-scale experiments, real municipa... [more]
Modified Biochar—A Tool for Wastewater Treatment
Marek Kopecký, Ladislav Kolář, Petr Konvalina, Otakar Strunecký, Florina Teodorescu, Petr Mráz, Jiří Peterka, Radka Váchalová, Jaroslav Bernas, Petr Bartoš, Feodor Filipov, Daniel Bucur
April 3, 2023 (v1)
Subject: Environment
Keywords: biochar, fertilizer, iron(III) phosphate, phosphorus, purification, recycling, Wastewater
Global deposits of concentrated phosphates, which are a necessary source for the production of phosphate fertilizers, are limited. These reserves keep getting thinner, and every day, large amounts of phosphorus end up in watercourses. In this study, we verified that modified biochar (saturated with FeCl3 solution and then neutralized with NaOH solution) can adsorb significant amounts of phosphorus from wastewater. Moreover, the agrochemical qualities of sludge water from a municipal wastewater treatment plant, struvite, phosphorus-saturated biochar, and iron(III) phosphate from a reused biochar filter were tested in this study. We determined the amount of mobile phosphorus as well as the amount of extractable phosphorus and its five fractions. It was found that modified biochar can hold one-third of the phosphorus amount contained in the commonly used agricultural fertilizer simple superphosphate (1 × 105 g of modified biochar captures up to 2.79 × 103 g of P). Moreover, plants can mor... [more]
A Novel Check-List Strategy to Evaluate the Potential of Operational Improvements in Wastewater Treatment Plants
Vojtěch Zejda, Vítězslav Máša, Šárka Václavková, Pavel Skryja
April 3, 2023 (v1)
Keywords: efficiency evaluation, methodology, overall efficiency, parameter analysis, Wastewater, WWTP
With increasing demands for cleaning and purification of water, wastewater treatment plants (WWTP) require their most efficient operation. The operators are thus obliged to constantly review the efficiency of the processing units and technological equipment of WWTPs and seek opportunities for improvements. To increase the efficiency of particular equipment, the important parameters to be used for the intensification must be correctly selected. A common WWTP consists of different types of processing units, where the basic parameters can be changed to achieve the highest efficiency (i.e., maximum output with minimum energy consumption) in the WWTP. However, due to many possible technologies in the wastewater treatment process, the combinations of processing units can be complex. In such cases, the efficiency assessment can be misleading if only basic parameters were accessed. Moreover, single-unit intensification can potentially improve the efficiency of the unit itself but cannot guaran... [more]
The Influent Effects of Flow Rate Profile on the Performance of Microbial Fuel Cells Model
Szymon Potrykus, Sara Mateo, Janusz Nieznański, Francisco Jesús Fernández-Morales
April 3, 2023 (v1)
Subject: Biosystems
Keywords: electric power generation, flow rate, microbial fuel cells, Modelling, Wastewater
The energy contained in wastewaters has been identified as a promising sustainable energy resource that could be harvested by using microbial fuel cells (MFC). When dealing with real wastewaters, the MFCs should be able to manage high flow rates and flow rates fluctuations. In this work, the short-term effects of the influent flow rate variations on the performance of a microbial fuel cell has been studied. With this aim, the influent flow rate was stepwise increased from 0.72 to 7.2 L/d and then stepwise decreased. The obtained results indicate that, on the one hand, an increase in the influent flow rate leads to higher chemical oxygen demand removal rates up to 396 g/(L/d) and higher electric power generation almost 18 mW/m2, but to lower coulombic efficiencies. On the other hand, the reduction of the flow rate increases the coulombic efficiencies, as well as the percentage of chemical oxygen demand removed, but decreases electric power generation. In the short-term, the exposition t... [more]
Biofouling Removal from Membranes Using Nonthermal Plasma
Irena Maliszewska, Tomasz Czapka
March 31, 2023 (v1)
Subject: Environment
Keywords: biofouling, membrane, nonthermal plasma, Wastewater
An essential aspect of wastewater treatment systems based on membranes is fouling, which leads to a decrease in their performance and durability. The membrane biofouling is directly related to the deposition of biological particles (e.g., microorganisms in the form of biofilm) on the membrane surface. The objective of the study was to investigate the possibility of using nonthermal plasma for membrane treatment to overcome the biofouling problem. The removal of biological cells from the membrane surface was performed in a dielectric barrier discharge (DBD) plasma. The biofoulant (i.e., activated sludge) on the surface of membranes was treated with plasma for 3−10 min, corresponding to a plasma dose of 13−42 J cm−2. Results of biofouling removal studies indicated that the process was very efficient (i.e., lethal effect was also observed) and dependent on the type of membrane and exposure time to the nonthermal plasma. Moreover, investigations of the influence of plasma treatment on extr... [more]
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