scholarly journals Clay-biodegradable polymer combination for pollutant removal from water

2015 ◽  
Vol 8 (2) ◽  
pp. 177-196 ◽  
Author(s):  
M. F. Mohd Amin ◽  
S. G. J. Heijman ◽  
L. C. Rietveld

<p><strong>Abstract.</strong> In this study, a new treatment alternative is investigated to remove micropollutants from wastewater effectively and in a more cost-effective way. A potential solution is the use of clay in combination with biodegradable polymeric flocculants. Flocculation is viewed as the best method to get the optimum outcome from the combination of clay with starch. Clay is naturally abundantly available and relatively inexpensive compared to the conventional adsorbents used. Experimental studies were carried out with four different clays to select the best clay for further optimisation. The atrazine removal achieved is in the range of 10–99 % based on the clay concentration of 10–50 g L<sup>−1</sup>. Optimisation of the best clay performer leads towards atrazine reduction of > 99 % with a dosage of 100 mg L<sup>−1</sup>. The best and underperforming clays were then tested in other experiments with the addition of cationic starch flocculants. In this experiment, the addition of a polymer increased the atrazine removal for the underperforming clay to 46 % with only 10 mg L<sup>−1</sup> clay dosages. The clay flocculation test was also performed to test the flocculation efficiency of clays by the polymer. Approximately 80–84 % of the clay is flocculated, which shows exceptional flocculation efficiency in removing both clays and atrazine from the water matrices.</p>

2016 ◽  
Vol 73 (7) ◽  
pp. 1719-1727 ◽  
Author(s):  
M. F. Mohd Amin ◽  
S. G. J. Heijman ◽  
L. C. Rietveld

In this study, a new, more effective and cost-effective treatment alternative is investigated for the removal of pharmaceuticals from wastewater treatment plant effluent (WWTP-eff). The potential of combining clay with biodegradable polymeric flocculants is further highlighted. Flocculation is viewed as the best method to get the optimum outcome from clay. In addition, flocculation with cationic starch increases the biodegradability and cost of the treatment. Clay is naturally abundantly available and relatively inexpensive compared to conventional adsorbents. Experimental studies were carried out with existing naturally occurring pharmaceutical concentrations found and measured in WWTP-eff with atrazine spiking for comparison between the demineralised water and WWTP-eff matrix. Around 70% of the total measured pharmaceutical compounds were removable by the clay–starch combination. The effect of clay with and without starch addition was also highlighted.


2014 ◽  
Vol 1024 ◽  
pp. 11-14 ◽  
Author(s):  
Mohamad Faiz Mohd Amin ◽  
S.G.J. Heijman ◽  
L.C. Rietveld

The effluent of wastewater treatment plants (WWTPs) is an important source of priority substances and is, therefore, one of the bottlenecks in achieving the European Water Framework Directive (WFD) objectives. At various locations in the Netherlands, standard for priority substances are exceeded. The current concern regarding the cost and treatment method of these micropollutants in receiving waters may call for new approaches in wastewater treatment. In this study, a new treatment alternative is developed to remove micropollutant and wastewater parameter effectively and in a more cost effective way. A potential solution is the used of clay coupled with biodegradable polymer flocculants. Clay is naturally abundant and relatively inexpensive compared to currently conventional used adsorbent which can also act as coagulants. Experimental studies were carried out with four different nanoclay to select the best nanoclay for further optimisation. The atrazine removal percentage archived is in the range of 10-99% based on the nanoclay concentration of 0.01-50 g/L. Optimisation of best nanoclay performer leads towards atrazine reduction of >99% with dosage of 0.1 g/L. The best and underperformed nanoclay then tested in other experiments with the addition of cationic starch flocculants. In this experiment, the addition of polymer increased the atrazine removal for the underperformer nanoclay to 46% with only 0.01 g/L clay dosages. This new approach in dealing with both micropollutant and wastewater parameter is promising and might help in reducing the compound concentration and the operational cost. However, further analysis and optimisation is required before any conclusion can be made.


2002 ◽  
Author(s):  
Sandra Almeida ◽  
Sandra G. Leichliter ◽  
Linda K. Hervig ◽  
Jackson Streeter ◽  
Karen Maxwell-Williams

2021 ◽  
Vol 13 (2) ◽  
pp. 15-24
Author(s):  
Amboko Benjamin Muhiwa ◽  
Mathias Fru Fonteh ◽  
Estella Buleng Tamungang Njoyim ◽  
François N. Gapgue

In recent years, research on biochar as an eco-friendly material and cost-effective means for water treatment, soil amendment and carbon sequestration has gained more attention due to the availability of feedstock, the simplicity of the preparation methods, and their enhanced physico-chemical properties. Given that pyrolysis temperature and resident time amongst other factors have significant effect on biochar’s pollutant removal efficacy, this study focused on the evaluation of some properties of biochars produced by pyrolysis (500 - 600 °C) from Entandrophragma cylindricum (ECB), Eucalyptus maiden (EMB), Milicia excelsa (MEB) and Ocotea michelsonie (OMB) sawdusts for their water treatment potentials by using standardized methods. Biomass generated from wood mill in the city of Goma (DR Congo) is valorised for the first time as potential water  purifier. The highest yield was obtained from OMB (36.6%) which was found to be significantly greater that those of ECB and EMB (p<0.05). All the biochars had neutral to weakly alkaline pH (7.10-7.90), very high porosity (92-94%, with EMB having the highest value) and ash content between 9.40 and 18.40%, with the highest value attributed to OMB). Most physical and chemical characteristics of biochars varied significantly due to different wood species. Potential toxic elements were far belowenvironmental threshold values and exchangeable cations were equally detected in the biochars. The obtained biochars are therefore seen as good media for water treatment.


Author(s):  
A. N. Gavrilov

The problem of modeling complex resource-intensive processes of plasma synthesis of carbon nanostructures (CNS) on the basis of mathematical and numerical methods of solution, focused on the use of parallel and distributed computing for processing large amounts of data, allowing to investigate the relationship and characteristics of processes to obtain an effective, cost-effective method of synthesis of CNS (fullerenes, nanotubes), is an actual theoretical and practical problem. This article deals with the problem of mathematical modeling of motion and interaction of charged particles in a multicomponent plasma based on the Boltzmann equation for the synthesis of ONS by thermal sublimation of graphite. The derivation of the collision integral is presented allowing to perform a numerical solution of the Boltzmann - Maxwell equations system with respect to the arc synthesis of CNS. The high order of particles and the number of their interactions involved simultaneously in the process of synthesis of CNS requires significant costs of machine resources and time to perform numerical calculations on the constructed model. Application of the large particle method makes it possible to reduce the amount of computing and hardware requirements without affecting the accuracy of numerical calculations. The use of parallel computing technology on the CPU and GPU with the use of Nvidia CUDA technology allows you to organize all the General-purpose calculations for the developed model based on the graphics processor of the personal computer graphics card, without the use of supercomputers or computing clusters. The results of experimental studies and numerical calculations confirming the adequacy of the developed model are presented. Obtained quantitative characteristics of the total pairwise interactions between the carbon particles and interactions with the formation of clusters of carbon with various types of ties in the plasma of the interelectrode space which are the basis of the synthesized nanostructures. The formation of carbon clusters occurs in the entire interelectrode space of the plasma with different intensity and depends on the process parameters.


2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Seyyed Mojtaba Mousavi ◽  
Seyyed Alireza Hashemi ◽  
Seyed Mohammad Iman Moezzi ◽  
Navid Ravan ◽  
Ahmad Gholami ◽  
...  

Nowadays, pollution of the environment is a huge problem for humans and other organisms’ health. Conventional methods of pollutant removal like membrane filtration or ion exchange are not efficient enough to lower the number of pollutants to standard levels. Biological methods, because of their higher efficiency and biocompatibility, are preferred for the remediation of pollutants. These cost-effective and environment-friendly methods of reducing pollutants are called bioremediation. In bioremediation methods, enzymes play the most crucial role. Enzymes can remedy different types of organic and inorganic pollutants, including PAHs, azo dyes, polymers, organocyanides, lead, chromium, and mercury. Different enzymes isolated from various species have been used for the bioremediation of pollutants. Discovering new enzymes and new subtypes with specific physicochemical characteristics would be a promising way to find more efficient and cost-effective tools for the remediation of pollutants.


2005 ◽  
Vol 50 (3) ◽  
pp. 159-166 ◽  
Author(s):  
Jeffrey S Hoch ◽  
Carolyn S Dewa

Objective: This paper describes the main types of economic evaluation techniques. Method: To examine the strengths and limitations of different types of economic evaluations, we used a hypothetical example to review the reasoning underlying each method and to illustrate when it is appropriate to use each method. Results: The choice of economic evaluation method reflects a decision about what should represent “success” and how success should be valued. Measures of benefit and cost must be considered systematically and simultaneously. Claiming that a new treatment is cost-effective requires making a value judgment based on the personal beliefs of the claimant. Even when cost and effect data are objective, a verdict of cost-effective is subjective. The conclusions of an economic study can change significantly, depending on which patient outcome is used to measure success. Conclusions: Clinicians must be sure that important patient outcomes are not excluded from economic evaluations. Economic evaluation is a process designed to produce an estimate rather than a decision. New treatment can be more costly and still be cost-effective (if the extra benefit is valued more than the extra cost to produce it). However, since economic evaluation does not explicitly consider a decision maker's available budget, a new treatment can be deemed cost-effective but too expensive to approve.


Author(s):  
Rima Klimaviciute ◽  
Joana Bendoraitiene ◽  
Edita Lekniute ◽  
Algirdas Zemaitaitis

Author(s):  
Zipeng Guo ◽  
Lu An ◽  
Sushil Lakshmanan ◽  
Jason Armstrong ◽  
Shenqiang Ren ◽  
...  

Abstract The macro-porous ceramics has promising durability and thermal insulation performance. As porous ceramics find more and more applications across many industries, a cost-effective and scalable additive manufacturing technique for fabricating macro-porous ceramics is highly desirable. Herein, we reported a facile additive manufacturing approach to fabricate porous ceramics and control the printed porosity. Several printable ceramic inks were prepared, the foaming agent was added to generate gaseous bubbles in the ink, followed by the direct ink writing and the ambient-pressure and room-temperature drying to create the three-dimensional geometries. A set of experimental studies were performed to optimize the printing quality. The results revealed the optimal process parameters for printing the foamed ceramic ink with a high spatial resolution and fine surface quality. Varying the concentration of the foaming agent enables the controllability of the structural porosity. The maximum porosity can reach 85%, with a crack-free internal porous structure. The tensile tests showed that the printed macro-porous ceramics possessed enhanced durability with the addition of fiber. With a high-fidelity 3D printing process and the precise controllability of the porosity, we showed that the printed samples exhibited a remarkably low thermal conductivity and durable mechanical strength.


2021 ◽  
Vol 37 (S1) ◽  
pp. 17-18
Author(s):  
Richard Boldero ◽  
Thomas Curran ◽  
Kath Haines ◽  
Miranda Morton ◽  
Phil A. Routledge

IntroductionThe New Treatment Fund (NTF), launched in January 2017, aims to support the faster introduction of new medicines recommended by the National Institute for Health and Care Excellence (NICE) and the All Wales Medicines Strategy Group (AWMSG). The NTF requires seven health boards and one trust to make recommended medicines available within 60 days of any positive recommendation decision. The project goal was to develop a system for demonstrating how monitoring the NTF improves medicines access for the people of Wales.MethodsThe process was derived via a series of task and finish group meetings with relevant stakeholders. The monitoring criteria were agreed through a collaborative expert approach using a nominal group technique. This determined a minimal dataset of formulary status, which included time to formulary addition. Pre-NTF medicines data (n = 59) were available for a six-month period.ResultsBy the three-year milestone of the NTF, the average time taken for newly recommended medicines (n = 219) to become available to patients across Wales had decreased by eighty-five percent from 90 to 13 days (p < 0.01).ConclusionsAn innovative and robust system has been created for accurately monitoring the formulary addition of medicines within the NTF, supporting the rapid and comprehensive uptake of medicines deemed clinically and cost effective by NICE and the AWMSG.


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