scholarly journals Graphene-Based Nanomaterials in Soil: Ecotoxicity Assessment Using Enchytraeus crypticus Reduced Full Life Cycle

Nanomaterials ◽  
2019 ◽  
Vol 9 (6) ◽  
pp. 858 ◽  
Author(s):  
Monique C. P. Mendonça ◽  
Natália P. Rodrigues ◽  
Marcelo B. de Jesus ◽  
Mónica J. B. Amorim

Graphene-based nanomaterials (GBNs) possess unique physicochemical properties, allowing a wide range of applications in physical, chemical, and biomedical fields. Although GBNs are broadly used, information about their adverse effects on ecosystem health, especially in the terrestrial environment, is limited. Therefore, this study aims to assess the toxicity of two commonly used derivatives of GBNs, graphene oxide (GO) and reduced graphene oxide (rGO), in the soil invertebrate Enchytraeus crypticus using a reduced full life cycle test. At higher exposure concentrations, GO induced high mortality and severe impairment in the reproduction rate, while rGO showed little adverse effect up to 1000 mg/kg. Collectively, our body of results suggests that the degree of oxidation of GO correlates with their toxic effects on E. crypticus, which argues against generalization on GBNs ecotoxicity. Identifying the key factors affecting the toxicity of GBNs, including ecotoxicity, is urgent for the design of safe GBNs for commercial purposes.

2017 ◽  
Vol 36 (11) ◽  
pp. 2934-2941 ◽  
Author(s):  
Fátima C.F. Santos ◽  
Susana I.L. Gomes ◽  
Janeck J. Scott-Fordsmand ◽  
Mónica J.B. Amorim

2016 ◽  
Vol 318 ◽  
pp. 608-614 ◽  
Author(s):  
Rita C. Bicho ◽  
Tânia Ribeiro ◽  
Natália P. Rodrigues ◽  
Janeck J. Scott-Fordsmand ◽  
Mónica J.B. Amorim

2021 ◽  
Author(s):  
Onyeka Onwuemene

Abstract This paper discusses how production rates can be sustained and further increased from an indepth gas-lift design that considers the holistic properties associated oil and gas Well production lifecycles. An example is shown of a Well 58 in a field onshore Nigeria which was shut-in for 2-days as part of scheduled Field shut-down. After several failed attempts to restart the Well post shut-down period, lessons learnt analysis indicated that while the affected Well had all the required gas-lift system installed, it's inability to flow may have been due to inadequate gas-lift design that did not account for the full life cycle of the reservoir, Well and surface facilities. A major re-analysis is carried out on the gas-lift design technique, this time capturing key requirements and the resultant proposal is discussed in detail. The proposed gaslift design optimizes the depth of gas injection with consideration given to the latter production phase of the the Well. Through the example of Well 58, this paper outlines and proposes a checklist of recommendations for gas lift design for new Wells and re-working or workover of existing gas-lift installations from which Well performance can be sustained and optimized. Even if quality gaslift-production results can be achieved through a wide range of other activities such as; special training for production operators, optimizing gas injection rates, modifying surface piping systems, identifying and replacing defective wireline-retrievable gas-lift valves, the most important variable that will ensure the full benefit of the above listed range of activities is the improved gas-lift design technique. Although Well 58 was revived via unconventional methods, the recorded 3-week downtime and the associated financial losses could have been avoided if an adequate gas lift design as proposed in this paper was explored during the Well planning and completion.


Ecotoxicology ◽  
2015 ◽  
Vol 24 (5) ◽  
pp. 1053-1063 ◽  
Author(s):  
Rita C. Bicho ◽  
Fátima C. F. Santos ◽  
Micael F. M. Gonçalves ◽  
Amadeu M. V. M. Soares ◽  
Mónica J. B. Amorim

2017 ◽  
Vol 224 ◽  
pp. 117-124 ◽  
Author(s):  
Rita C. Bicho ◽  
Fátima C.F. Santos ◽  
Janeck J. Scott-Fordsmand ◽  
Mónica J.B. Amorim

2022 ◽  
Vol 162 ◽  
pp. 108054
Author(s):  
Xiaoshu Qin ◽  
Chang Peng ◽  
Gaozheng Zhao ◽  
Zengye Ju ◽  
Shanshan Lv ◽  
...  

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