scholarly journals Removal of nutrients from aquaculture residual water: A review

2021 ◽  
Vol 16 (6) ◽  
pp. 1-15
Author(s):  
Jéssica Mendonça Ribeiro Cargnin ◽  
Jair Juarez João
Keyword(s):  
Production Process ◽  
Environmental Impacts ◽  
Effluent Treatment ◽  
Nitrogen Compounds ◽  
Residual Water ◽  
Treatment Techniques ◽  
Biological Removal ◽  
Current Water ◽  
Aquaculture Wastewater ◽  
Protein Rich

Aquaculture plays an important role in providing protein-rich foods, meeting the growing demand for fish. However, aquaculture is a potentially polluting activity, especially with regard to water pollution, due to the improper disposal of wastewater from the production process. Aquaculture wastewater is rich in nutrients (ammonia, nitrate, nitrite and phosphorus) and organic matter, and is commonly discharged into the environment without proper treatment. This can cause a series of environmental impacts and aggravate the current water crisis. Due to the importance and need to reduce environmental impacts, plan the use of water resources and achieve an efficient and sustainable production process, many researchers have focused their studies on effluent treatment techniques designed to remove these nutrients. This article therefore presents an updated review of the main physicochemical and biological techniques used in the removal of nutrients, which can mitigate environmental problems arising from aquaculture activities and contribute to the sustainability of the activity. Keywords: biological removal, nitrogen compounds, sustainable activity.

Carbon footprint and water footprint assessment of virgin and recycled polyester textiles

2021 ◽  
pp. 004051752110062
Author(s):  
Weiran Qian ◽  
Xiang Ji ◽  
Pinghua Xu ◽  
Laili Wang
Keyword(s):  
Production Process ◽  
Environmental Impacts ◽  
Carbon Footprint ◽  
Water Scarcity ◽  
Water Footprint ◽  
Oxygen Demand ◽  
Polyester Fabric ◽  
Total Carbon ◽  
Fabric Production ◽  
Water Eutrophication

Recycled polyester textile fibers stemming from waste polyester material have been applied in the textile industry in recent years. However, there are few studies focusing on the evaluation and comparison of the environmental impacts caused by the production of virgin polyester textiles and recycled polyester textiles. In this study, the carbon footprint and water footprint of virgin polyester textiles and recycled polyester textiles were calculated and compared. The results showed that the carbon footprint of the virgin polyester textiles production was 119.59 kgCO2/100 kg. Terephthalic acid production process occupied the largest proportion, accounting for 45.83%, followed by polyester fabric production process, ethylene production process, paraxylene production process, ethylene glycol production process and polyester fiber production process. The total carbon footprint of waste polyester recycling was 1154.15 kgCO2/100 kg, approximately ten times that of virgin polyester textiles production. As for the water footprint, it showed that virgin polyester fabric production and recycled polyester fabric production both had great impact on water eutrophication and water scarcity. Chemical oxygen demand caused the largest water eutrophication footprint, followed by ammonia-nitrogen and five-day biochemical oxygen demand. The water scarcity footprint of virgin polyester fabric production and recycled polyester fabric production was 5.98 m3 H2Oeq/100 kg and 1.90 m3 H2Oeq/100 kg, respectively. The comprehensive evaluation of carbon footprint and water footprint with the life cycle assessment polygon method indicated that the polyester fabric production process exhibited greater environmental impacts both for virgin polyester and recycled polyester.

scholarly journals Application of Life Cycle Assessment and Machine Learning for High-Throughput Screening of Green Chemical Substitutes

2020 ◽  
Author(s):  
Xinzhe Zhu ◽  
Chi-Hung Ho ◽  
Xiaonan Wang
Keyword(s):  
Machine Learning ◽  
Life Cycle Assessment ◽  
Life Cycle ◽  
Production Process ◽  
Environmental Impacts ◽  
High Throughput ◽  
High Throughput Screening ◽  
Molecular Descriptors ◽  
Trifluoroacetic Anhydride ◽  
Chemical Materials

<p><a></a><a>The production process of many active pharmaceutical ingredients such as sitagliptin could cause severe environmental problems due to the use of toxic chemical materials and production infrastructure, energy consumption and wastes treatment. The environmental impacts of sitagliptin production process were estimated with life cycle assessment (LCA) method, which suggested that the use of chemical materials provided the major environmental impacts. Both methods of Eco-indicator 99 and ReCiPe endpoints confirmed that chemical feedstock accounted 83% and 70% of life-cycle impact, respectively. Among all the chemical materials used in the sitagliptin production process, </a><a>trifluoroacetic anhydride </a>was identified as the largest influential factor in most impact categories according to the results of ReCiPe midpoints method. Therefore, high-throughput screening was performed to seek for green chemical substitutes to replace the target chemical (i.e. trifluoroacetic anhydride) by the following three steps. Firstly, thirty most similar chemicals were obtained from two million candidate alternatives in PubChem database based on their molecular descriptors. Thereafter, deep learning neural network models were developed to predict life-cycle impact according to the chemicals in Ecoinvent v3.5 database with known LCA values and corresponding molecular descriptors. Finally, 1,2-ethanediyl ester was proved to be one of the potential greener substitutes after the LCA data of these similar chemicals were predicted using the well-trained machine learning models. The case study demonstrated the applicability of the novel framework to screen green chemical substitutes and optimize the pharmaceutical manufacturing process.</p>

scholarly journals Factors for Eco-Efficiency Improvement of Thermal Insulation Materials

2016 ◽  
Vol 678 ◽  
pp. 1-13 ◽  
Author(s):  
Jun Kono ◽  
Yutaka Goto ◽  
York Ostermeyer ◽  
Rolf Frischknecht ◽  
Holger Wallbaum
Keyword(s):  
Life Cycle ◽  
Physical Properties ◽  
Production Process ◽  
Environmental Impacts ◽  
Thermal Insulation ◽  
Foam Glass ◽  
Insulation Material ◽  
Contributing Factors ◽  
Insulation Materials ◽  
Thermo Physical Properties

Thermal insulation material is an important component to reduce the environmental impact of buildings through the reduction of energy consumption in the operation phase. However, the material itself has embodied environmental impacts for the value it provides. Eco-efficiency is a method that quantifies relation between the environmental performance and the created value of a product system. This study investigated contributing factors of the eco-efficiency of thermal insulation materials to support decision making of material manufacturers. For the improvement of eco-efficiency, the assessment was made in two scopes: investigating the contributing factors of impact caused at production processes; and thermal performance through thermo-physical properties. For quantifying environmental impacts, cradle-to-grave life cycle assessment (LCA) of each materials were made. The life cycle impact assessment (LCIA) indicators used were ReCiPe H/A and global warming potential (GWP100a). For the assessment of production process, the inventories of the materials were assigned to six categories: heat, chemicals, electricity, transportation, raw materials and wastes. Among the assessed materials, contribution of electricity and heat within the production process was large for foam glass which had the highest potential to improve the eco-efficiency which was by factor 1.72. The analysis on relation between thermo-physical properties and eco-efficiency based on product data of the materials highlighted the importance of density as an indicator upon development and use. Althoughdensity often gains less attention,the finding suggested the effectiveness of improving the efficiency by having lower density without compensating the performance of the materials.

scholarly journals NOVEL COMBINATION OF TRISODIUM CITRATE AND TRISODIUM PHOSPHATE IN REACTIVE DYEING OF COTTON: AN ATTEMPT TO REDUCE ENVIRONMENTAL IMPACT

2021 ◽  
Vol 55 (7-8) ◽  
pp. 901-909
Author(s):  
ANKIT SHARMA ◽  
JAVED SHEIKH
Keyword(s):  
Trisodium Citrate ◽  
Reactive Dye ◽  
Trisodium Phosphate ◽  
Effluent Treatment ◽  
Great Promise ◽  
Aquatic Life ◽  
Reactive Dyeing ◽  
Treatment Techniques ◽  
Inorganic Electrolyte ◽  
The Individual

"Reactive dyes are most widely used for dyeing cellulosic fabrics due to their excellent wet fastness properties, the brilliancy of shades and a wide gamut of colours. However, the exhaustion of reactive dye requires a large quantity of inorganic electrolyte, which results in excessive total dissolved solids (TDS) values of the resultant effluent. Such high TDS-containing effluents are challenging to treat and require advanced treatment techniques. The discharge of high-TDS containing effluent into water-bodies can increase the salinity of the aquatic system, which can affect the delicate biochemistry of the aquatic life. This necessitates the exploration of alternative chemicals for reducing the TDS of the effluents in reactive dyeing. The current study explores the alternate combination of trisodium citrate (TSC) and trisodium phosphate (TSP) as an eco-friendly replacement of inorganic salts and alkali in the dyeing of cotton by the exhaust process. The TSC-TSP combination resulted in an insignificant variation in exhaustion, fixation and fastness ratings compared to the conventional salt-soda combination. The colour values showed marginal variations in the individual cases of dyes. However, the use of the TSC-TSP combination showed a great promise in reducing the TDS of the effluent (by 66%), which is a major concern in effluent treatment. TSC being organic, some increase in COD/BOD values was obtained; however, the effluent remained in a category of easily treatable ones. "

scholarly journals Advanced oxidation processes employment for the degradation of lamivudine: kinetic assessment, toxicity study and mathematical modeling

2020 ◽  
Vol 55 (3) ◽  
pp. 249-260
Author(s):  
Adriane Rayssa Seguins Feliciano ◽  
Alex Leandro Andrade de Lucena ◽  
Rayany Magali da Rocha Santana ◽  
Léa Elias Mendes Carneiro Zaidan ◽  
Pollyanna Michelle da Silva ◽  
...  
Keyword(s):  
Advanced Oxidation Processes ◽  
Good Accuracy ◽  
Effluent Treatment ◽  
Toxicity Tests ◽  
Order Model ◽  
First Order ◽  
Treatment Techniques ◽  
Kinetic Assessment ◽  
Oxidative Processes ◽  
Uv C

Abstract Population growth has led to an increase in the production and use of synthetic compounds such as drugs, whose different classes are being investigated. However, the antiretrovirals are still poorly studied. Since the conventional treatments used in the effluent treatment plants have not been able to degrade these substances, other treatment techniques have been evaluated. Therefore, the objective of this work was to study and optimize the use of advanced oxidative processes (AOPs) in the degradation of lamivudine. It was found, initially, that the photo-peroxidation degraded 69% of the compound after 60 min of exposure to UV-C radiation, and that after evaluating the effect of the [H2O2], a degradation of 95% was achieved by using 250 mg L−1 of this reagent. The reaction kinetics showed a good fit to the pseudo-first-order model, and the artificial neural network MLP (3-12-1) demonstrated a good accuracy, managing to predict percentages of degradation for the studied AOP. Toxicity tests indicated an increase in the toxic effect on seeds, but the same was not observed in relation to enterobacteria. In general, the appropriateness of the application of AOP in the degradation of the aqueous solution has been demonstrated, with the largest studies regarding the effects of toxicity.

Membrane Treatment Strategies for Red Meat Abattoir Effluents

1992 ◽  
Vol 25 (10) ◽  
pp. 137-148 ◽  
Author(s):  
J. A. C. Cowan ◽  
F. MacTavish ◽  
C. J. Brouckaert ◽  
E. P. Jacobs
Keyword(s):  
South Africa ◽  
Water Conservation ◽  
Treatment Strategies ◽  
Red Meat ◽  
Effluent Treatment ◽  
Commercial Application ◽  
Small Scale ◽  
Dissolved Air Flotation ◽  
Treatment Techniques ◽  
Membrane Treatment

In water-scarce South Africa there is pressure on water-intensive industries to conserve water, and at the same time to reduce the organic and salinity concentrations discharged in effluents back (indirectly) to the water resources. These requirements are usually contradictory: effective water conservation will generally lead to more concentrated effluents, motivating the need, in some cases, for effluent pretreatment before discharge. Wide-ranging effluent pretreatment trials have been carried out at a number of red meat abattoirs over the past few years, under funding from the Water Research Commission. Fat removal, screening and dissolved air flotation (DAF) trials have confirmed the usefulness of such processes, but results from treatment with membranes have been both exciting and promising. These treatment techniques have now been lifted from the research phase into commercial application on small scale (25 m3/d) using full size modules. The South African Abattoir Corporation, as the major representative of the industry in South Africa, has undertaken to assess the value of membrane treatment processes as a part of a number of effluent treatment strategies. This paper describes the experiences and future potential for abattoir effluent treatment by membrane processes. Ultrafiltration will consistently remove 90% COD, 85% phosphate from the effluent, and provide a relatively non-fouling feed for reverse osmosis which produces a high quality reusable water for abattoir use. Indicative costing shows the costs of membrane treatment compare favourably with anaerobic digestion as an alternative, and even to municipal effluent tariffs.

scholarly journals Biofloc production in activated sludge system treating shrimp farming effluent

2018 ◽  
Vol 23 (6) ◽  
pp. 1143-1152 ◽  
Author(s):  
Sandra Tedde Santaella ◽  
Maria do Socorro Vale ◽  
Clara Cabral Almeida ◽  
Willame de Araújo Cavalcante ◽  
Alberto Jorge Pinto Nunes ◽  
...  
Keyword(s):  
Activated Sludge ◽  
Oxygen Demand ◽  
Shrimp Farming ◽  
Effluent Treatment ◽  
Nitrogen Compounds ◽  
Suitable Alternative ◽  
Activated Sludge System ◽  
Feed Cost ◽  
Shrimp Feed ◽  
Farming Industry

ABSTRACT The release of wastewater and the shrimp feed cost are the main challenges faced by the shrimp farming industry. An alternative solution to both problems is biofloc production in a unit external to the farm, in an activated sludge system for effluent treatment. The treatment system’s influent was composed of the shrimp farm wastewater supplemented with urea and sugarcane molasses. The results show that the average removal of chemical oxygen demand was 71% and the average biofloc production in the reactor was approximately 1.5g.L-1. Adding molasses to the influent contributed to the increase in the quantity and diversity of existing microorganisms that are beneficial to cultured shrimp. The mass balance of nitrogen compounds confirmed that nitrification occurred in the system. Therefore, the use of the activated sludge system is a viable and environmentally suitable alternative to produce bioflocs and shrimp farming effluent treatment.

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