scholarly journals Adsorption and coagulation in wastewater treatment – Review

Abstract Wastewater issues became a complex challenge in the world. There are several methods in wastewater treatment, such as chemical, physical, biological, and the combination of each method. However, each process has advantages and disadvantages. The physicochemical methods are common methods used in wastewater treatment, such as adsorption and coagulation. Adsorption and coagulation are excellent methods to remove pollutants. The adsorption process is greatly influenced by pH, adsorbent dose, temperature, and contact time. Coagulant dose, settling time, and pH are the main factors in the coagulation process. Chemical material as an adsorbent and coagulant has been studied in previous research, but recently, to substitution chemical materials is a challenging subject. Natural substances are potential new materials in wastewater treatment and became popular due to their efficiency and environment friendly characteristics. This review investigated the role of adsorption and coagulation in wastewater treatment and the utilization of natural materials as adsorbents and coagulants.

2020 ◽  
pp. 92-107 ◽  
Author(s):  
A. I. Bakhtigaraeva ◽  
A. A. Stavinskaya

The article considers the role of trust in the economy, the mechanisms of its accumulation and the possibility of using it as one of the growth factors in the future. The advantages and disadvantages of measuring the level of generalized trust using two alternative questions — about trusting people in general and trusting strangers — are analyzed. The results of the analysis of dynamics of the level of generalized trust among Russian youth, obtained within the study of the Institute for National Projects in 10 regions of Russia, are presented. It is shown that there are no significant changes in trust in people in general during the study at university. At the same time, the level of trust in strangers falls, which can negatively affect the level of trust in the country as a whole, and as a result have negative effects on the development of the economy in the future. Possible causes of the observed trends and the role of universities are discussed. Also the question about the connection between the level of education and generalized trust in countries with different quality of the institutional environment is raised.


2020 ◽  
pp. 124-131
Author(s):  
Olena P. Slavkova ◽  
Oksana I Zhilinska ◽  
Maksym Palienko

The article deals with the peculiarities of the formation and implementation of tax policy in the country. The analysis of change of tax receipts to the state and local budgets is carried out. The role of tax payments in the economic development of the country is determined. The efficiency of the state tax policy in Ukraine is analyzed, its advantages and disadvantages are determined. The important role of tax payments in stimulating economic and social development is substantiated. The analysis of the elasticity of change of indicators of economic development of the country from the change of volume of tax receipts to the budget is carried out. The necessity of improving the existing policy of establishing, accrual, payment, and distribution of tax revenues as one of the most promising areas to stimulate economic growth is concluded. Keywords: tax policy, revenues, tax evasion, state budget, elasticity, economic development


1992 ◽  
Vol 26 (7-8) ◽  
pp. 1915-1920
Author(s):  
D. Kinnersley

The scope for involving private capital participation in wastewater treatment and pollution control is attracting attention in a number of countries. After noting briefly some influences giving rise to this trend, this paper discusses frameworks in which such participation may be developed. In some aspects, there are choices available and it is essential to shape the private participation appropriately to the community's situation and problems, with due recognition of the hazards also involved. In other aspects, policy choices are more constrained, and there are requirements which it is suggested all private participation frameworks should provide for as clearly as possible. Effective private participation generally depends on re-designing and strengthening the role of government as the scale of its former role is reduced. Getting this re-design of the government role right is at least as important as making appropriate choices for format of private participation.


2019 ◽  
Vol 12 (2) ◽  
pp. 135-155 ◽  
Author(s):  
Muhammad Affan Zamir ◽  
Wasim Hakim ◽  
Siraj Yusuf ◽  
Robert Thomas

IIntroduction: Pancreatic Neuroendocrine Tumours (p-NETs) are an important disease entity and comprise of peptide-secreting tumours often with a functional syndrome. : Accounting for a small percentage of all pancreatic tumours, they have a good overall survival rate when diagnosed early, with surgery being curative. The role of nuclear medicine in the diagnosis and treatment of these tumours is evident. However, the vast majority of patients will require extensive imaging in the form of conventional radiological techniques. It is important for clinicians to have a fundamental understanding of the p-NET appearances to aid prompt identification and to help direct management through neoplastic staging. Methods: This article will review the advantages and disadvantages of conventional radiological techniques in the context of p-NETs and highlight features that these tumours exhibit. Conclusion: Pancreatic neuroendocrine tumours are a unique collection of neoplasms that have markedly disparate clinical features but similar imaging characteristics. Most p-NETs are small and welldefined with homogenous enhancement following contrast administration, although larger and less welldifferentiated tumours can demonstrate areas of necrosis and cystic architecture with heterogeneous enhancement characteristics. : Prognosis is generally favourable for these tumours with various treatment options available. However, conventional radiological techniques will remain the foundation for the initial diagnosis and staging of these tumours, and a grasp of these modalities is extremely important for physicians.


Neurosurgery ◽  
2020 ◽  
Author(s):  
Bledi C Brahimaj ◽  
Ryan B Kochanski ◽  
John J Pearce ◽  
Melike Guryildirim ◽  
Carter S Gerard ◽  
...  

Abstract The goal of glioma surgery is maximal safe resection in order to provide optimal tumor control and survival benefit to the patient. There are multiple imaging modalities beyond traditional contrast-enhanced magnetic resonance imaging (MRI) that have been incorporated into the preoperative workup of patients presenting with gliomas. The aim of these imaging modalities is to identify cortical and subcortical areas of eloquence, and their relationship to the lesion. In this article, multiple modalities are described with an emphasis on the underlying technology, clinical utilization, advantages, and disadvantages of each. functional MRI and its role in identifying hemispheric dominance and areas of language and motor are discussed. The nuances of magnetoencephalography and transcranial magnetic stimulation in localization of eloquent cortex are examined, as well as the role of diffusion tensor imaging in defining normal white matter tracts in glioma surgery. Lastly, we highlight the role of stimulated Raman spectroscopy in intraoperative histopathological diagnosis of tissue to guide tumor resection. Tumors may shift the normal arrangement of functional anatomy in the brain; thus, utilization of multiple modalities may be helpful in operative planning and patient counseling for successful surgery.


2021 ◽  
Author(s):  
Xinpeng Zhao ◽  
Zhimin Zhou ◽  
hu luo ◽  
Yanfei Zhang ◽  
Wang Liu ◽  
...  

Combined experiments and density functional theory (DFT) calculations provided insights into the role of the environment-friendly γ-valerolactone (GVL) as a solvent in the hydrothermal conversion of glucose into lactic acid...


2021 ◽  
pp. 073527512110299
Author(s):  
Jeremy E. Fiel

This article builds a framework for a relational approach to segregation that emphasizes structures of interactions, transactions, and ties between and within social categories. Rather than explaining segregation with dominants imposing formal rules or homophilic people sorting themselves, I highlight segregation’s emergence amid dueling control efforts among actors with malleable categorical identities. And rather than assuming segregation necessarily fuels cycles of inequality or persecution, I identify nuanced advantages and disadvantages for different actors in social conflict. I also explore an underappreciated role of institutions in segregation: They guide relations across different domains of activity that may have different degrees of segregation. An overarching theme is that segregation is not a specific thing with regular causes and effects but an inherently contradictory structural feature of relations that evolves as actors struggle for control.


Author(s):  
Nils Johansson

AbstractA problem for a circular economy, embedded in its policies, tools, technologies and models, is that it is driven by the interests and needs of producers, rather than customers and users. This opinion paper focuses on an alternative form of governance—agreements, which thanks to their bargaining approach brings actors from across the value chain into the policy process. The purpose of this opinion paper is to uncover and analyse the potential of such agreements for a circular economy. Circular agreements aim at increasing the circulation of materials and are an emerging form of political governance within the EU. These agreements have different names, involve different actors and govern in different ways. However, circular agreements seem to work when other types of regulations fail to establish circulation. These agreements bring actors together and offer a platform for negotiating how advantages and disadvantages can be redistributed between actors in a way that is more suitable for a circular economy. However, circular agreements are dependent on other policy instruments to work and can generate a free-rider problem with uninvolved actors. The agreements may also become too detailed and long term, which leads to problem shifting and lock-ins, respectively.


2021 ◽  
Vol 13 (4) ◽  
pp. 2332
Author(s):  
Lena Bjørlo ◽  
Øystein Moen ◽  
Mark Pasquine

Artificial intelligence (AI)-based decision aids are increasingly employed by businesses to assist consumers’ decision-making. Personalized content based on consumers’ data brings benefits for both consumers and businesses, i.e., with regards to more relevant content. However, this practice simultaneously enables increased possibilities for exerting hidden interference and manipulation on consumers, reducing consumer autonomy. We argue that due to this, consumer autonomy represents a resource at the risk of depletion and requiring protection, due to its fundamental significance for a democratic society. By balancing advantages and disadvantages of increased influence by AI, this paper addresses an important research gap and explores the essential challenges related to the use of AI for consumers’ decision-making and autonomy, grounded in extant literature. We offer a constructive, rather than optimistic or pessimistic, outlook on AI. Hereunder, we present propositions suggesting how these problems may be alleviated, and how consumer autonomy may be protected. These propositions constitute the fundament for a framework regarding the development of sustainable AI, in the context of online decision-making. We argue that notions of transparency, complementarity, and privacy regulation are vital for increasing consumer autonomy and promoting sustainable AI. Lastly, the paper offers a definition of sustainable AI within the contextual boundaries of online decision-making. Altogether, we position this paper as a contribution to the discussion of development towards a more socially sustainable and ethical use of AI.


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