A. Sumaila; M. M. Ndamitso; A. S. Ambali; Y. A. Iyaka; J. O. Tijani
Abstract
This work presents the green preparation of chitosan stabilized silver nanocomposite using aqueous leaf extracts of Nicotiana tobaccum. The prepared chitosan – silver nanocomposite was characterized by the ultraviolet-visible (UV-Vis) spectroscopy, X-ray diffraction (XRD), high resolution scanning ...
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This work presents the green preparation of chitosan stabilized silver nanocomposite using aqueous leaf extracts of Nicotiana tobaccum. The prepared chitosan – silver nanocomposite was characterized by the ultraviolet-visible (UV-Vis) spectroscopy, X-ray diffraction (XRD), high resolution scanning electron microscopy (HRSEM) and Fourier transform infrared (FTIR) spectroscopy. The nanocomposite was employed to remove copper and iron metal ions from electroplating effluent via batch adsorptions as a function of contact time, adsorbent dosage and temperature. The XRD results of the nanocomposite showed reflections at 2θ of 38.04°, 44.650 and 64.45° for the presence of silver nanoparticles and 9.29° and 19.300 for chitosan. The HRSEM image of the nanocomposite shows the silver nanoparticles embedded in the chitosan polymer matrix, to create pores on the surface of the chitosan. The maximum percentage removal of copper and iron by chitosan – silver nanocomposite were 94.76 % and 98.80 % respectively at temperature of 363 K in 60 minutes using adsorbent dosage of 25 mg. The results were well fitted by all the tested isotherm models but best fit into jovanovic isotherm models. Kinetic data for Cu and Fe ions followed the Elovich model which implies multilayer adsorption. The result of this study show that chitosan - silver nanocomposite has been prepared and it exhibit high adsorption efficiency for copper and iron from electroplating effluent.
M. Massoud; M. Erhayem; F. Al-Tohami
Abstract
In the present study, batch adsorption experiments of hazardous cadmium ions, Cd(II), onto low-cost Dodonaeae Viscose Legs (DVLs) surface were conducted with respect to contact time, solution pH, adsorbent dosage, initial Cd concentration and temperature. Sorption isotherm, kinetic and thermodynamic ...
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In the present study, batch adsorption experiments of hazardous cadmium ions, Cd(II), onto low-cost Dodonaeae Viscose Legs (DVLs) surface were conducted with respect to contact time, solution pH, adsorbent dosage, initial Cd concentration and temperature. Sorption isotherm, kinetic and thermodynamic models were used to describe the equilibrium stage and their constants were determined. The DVLs were used without chemical or physical activation processes. The results showed that the optimum adsorption capacity of DVLs for Cd(II) ions was found to be 25.29 mg/g at solution pH 5.26, 50 min and 303K. DVL adsorption data was fitted well with Langmuir isotherm. The mean free energy was found to be 1.82E-02 using Dubinin-Radushkevich (DRK) isotherm, which indicates that the adsorption of Cd(II) ions onto DVL surface is physical adsorption. The activation energy (Ea) was 3.06 kJ/mol, which confirms that Cd(II)-DVL adsorption process is physical sorption. Pseudo-first-order, pseudo-second-order, Elovich, intra-particle and extra-particle diffusion models were used to describe the adsorption kinetics. The results show strong correspondence to a pseudo-second-order kinetics. Thermodynamic parameters suggested that the adsorption of Cd(II) ions onto DVL surface is an exothermic process.
A. D. Mahmud; A. Hamza; A. Zubair; B. Mukhtar
Abstract
ZnO-ZnFe2O4 composite was applied for photocatalytic degradation of naphthalene in fresh and saline waters under visible light irradiation. The effects of initial concentration of naphthalene, ZnO-ZnFe2O4 dosage and salinity on photocatalytic degradation of naphthalene were investigated using the central ...
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ZnO-ZnFe2O4 composite was applied for photocatalytic degradation of naphthalene in fresh and saline waters under visible light irradiation. The effects of initial concentration of naphthalene, ZnO-ZnFe2O4 dosage and salinity on photocatalytic degradation of naphthalene were investigated using the central composite design. Statistically significant model quadratic equation was developed for photocatalytic degradation of naphthalene using ZnO-ZnFe2O4 composite. The most significant parameter in the photocatalytic degradation is the ZnO-ZnFe2O4 dosage followed by the initial concentration of naphthalene and then salinity. The highest photocatalytic degradation of naphthalene was achieved at salinity of zero (that is in fresh water). The predicted optimum conditions for photocatalytic degradation of naphthalene using the ZnO-ZnFe2O4 composite are: initial naphthalene concentration of 16.8 mg/l, ZnO-ZnFe2O4 dosage of 0.50 g/l, and salinity of 0 ppt. The model quadratic equation was validated by performing experiments under the predicted optimum values. The experimental and the predicted values of naphthalene degradation under the predicted optimum values are 99.04 % and 98.8 %. Hence, the developed quadratic model is reliable for predicting photocatalytic degradation of naphthalene using ZnO-ZnFe2O4 composite.
M. Firoozzadeh; A. H. Shiravi; M. Shafiee
Abstract
Paper mill producing several type papers has a wastewater treatment plant with an aerated lagoon system to remove their pollutants. But the removal efficiency of this system is still low so that the effluent is still not complying with the Indonesian of effluent quality standards yet. It needs pre-treatment ...
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Paper mill producing several type papers has a wastewater treatment plant with an aerated lagoon system to remove their pollutants. But the removal efficiency of this system is still low so that the effluent is still not complying with the Indonesian of effluent quality standards yet. It needs pre-treatment plant before aerated lagoon. In an effort to improve the performance of wastewater treatment plant, study of wastewater characteristics, wastewater treatment, the establishment of treatment systems and equipment design have been carried out. After construction of pre-treatment plant, the field trial of wastewater treatment plant using wastewater originated from several type of paper produced was conducted. Result of laboratory-scale experiment showed that the paper mill needs a wastewater treatment with physical-chemical system before aerated lagoon treatment. Field trial of wastewater treatment showed that the removal of suspended solids (TSS) of 97%, COD of 88%, BOD5 of 85%, and a pH of 6.2 to 7.7 could be obtained using 5 - 10 % NaOH solution at doses of 50-240 mg/L and 0.1% cationic polyelectrolyte (PE) solution as flocculants at dose of 1.0 to 1.5 mg/L. Application of physical-chemical treatment plant can lighten the load on an aerated lagoon treatment. Effluent quality of aerated lagoon discharged into environment has met the Indonesian of effluent quality standard.
J. Rosenlund; C. Legrand
Abstract
In the Algoland project, microalgae are used to clean water and air from industry. This is built on a long standing collaboration between research, industry and society. In this way Algoland supports the transition to a circular economy by turning pollution into biomass and potential products. This paper ...
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In the Algoland project, microalgae are used to clean water and air from industry. This is built on a long standing collaboration between research, industry and society. In this way Algoland supports the transition to a circular economy by turning pollution into biomass and potential products. This paper evaluates the potential for microalgae as an ecosystem service in industries from a circular economy perspective. The business model canvas was used in a workshop with stakeholders and researchers to discuss the challenges and opportunities for an industrial platform. Results showed that the established canvas model needs to be complemented by circular models; in order to be able to include ecosystem services. In this paper a circular canvas model is developed to be used in similar approaches.
T. Mumladze; M. Tatariants; A. Rimšaitė; S. Yousef; G. Denafas
Abstract
Multilayer Packaging wastes are one of the major problem in the world. About 6 billion tons of packages are generated per year in the world (in EU is about 82 million tons per year). Multilayer packaging foils are approximately 17% of all produced packaging films. Most produced multilayer film is based ...
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Multilayer Packaging wastes are one of the major problem in the world. About 6 billion tons of packages are generated per year in the world (in EU is about 82 million tons per year). Multilayer packaging foils are approximately 17% of all produced packaging films. Most produced multilayer film is based on different polymers, such as: polyethylene terephthalate (PET), polypropylene (PP), and polyethylene (PE) as main components, and an aluminum layer. However, because of their poor recyclability, most multi layers are usually incinerated or landfill, this is counteracting the efforts towards a circular economy. There are different recycling methods for this type of waste, but the main problem is that there is less company which recycling multilayer packaging foils. Also, it is very important that, mostly they recovering only one or two components and others are burned or landfilled. The aim of this research was to find the most suitable solvent for recycling multilayer packaging foils and recover two common components: polymer and Al foil. For the first experiment, there was chosen multilayer packaging foil’s different samples, such as: packaging for chocolate, chips, medicines and coffee. There was used several chemicals: acetic acid, acetone, dimethyl formamide, ethanol, ethyl acetate and toluene. These solvents are on the list of green chemicals and they were selected, due to their less impact on environment and human health. The recycling process and result was different for each samples and solvents, because of their individual characteristics.
K. Mazur; K. Roman; K. Borek
Abstract
About methods of reduction of ammonia emissions and greenhouse gas (GHG) from livestock production were investigated. Many techniques required high investments costs by low reducing level of emissions. Among all known methods, the most effective method is slurry cooling and decreasing slurry pH to obtain ...
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About methods of reduction of ammonia emissions and greenhouse gas (GHG) from livestock production were investigated. Many techniques required high investments costs by low reducing level of emissions. Among all known methods, the most effective method is slurry cooling and decreasing slurry pH to obtain high ammonia emission reductions. When we talk about GHG, anaerobic digestion and slurry separation are desired solutions. Regarding sustainable development in agriculture production, not only environmental effects, but also economy is important.
A. Zentner; C. Dornack
Abstract
The mechanical biological treatment plant of Freienhufen is used to stabilize residual waste. Since the rural districts Elbe - Elster and Oberspreewald - Lausitz match their waste management with federal law, organic fraction of municipal solid waste (OFMSW) will be collected separately in future. Hence ...
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The mechanical biological treatment plant of Freienhufen is used to stabilize residual waste. Since the rural districts Elbe - Elster and Oberspreewald - Lausitz match their waste management with federal law, organic fraction of municipal solid waste (OFMSW) will be collected separately in future. Hence the anaerobic digestion process has to be converted. The accomplishment has to refer to the existing operating regime to reduce investment costs. This contains a wet fermentation. In order to facilitate the conversion of the operating process, suitable particle sizes and volumetric loads have to be examined. In addition, the liquid phase of the digestate shall be recirculated maximal to save both fresh water and waste water disposal costs. The one year lasting investigations were performed in lab-scale with a various number of reactors. Before feeding the bio-waste was pre-treated. In order to do that, the bio-waste was milled to particle sizes of 2, 4, 8, and 10 mm. In addition, the digestate was dewatered to gain process water. While using the process water fresh water was substituted in varying proportions. The feeding of the reactors was adjusted to the standards of the operating plant. For that reason, the dry matter content in the reactor was adjusted at 10.5 %. Depending on the delivered raw material, this restriction led both to unsteady water requirements and volumetric loading. As a result of investigations an optimal particle size as well as optimal proportion of recirculated process water were defined. For that reason, comprehensive analyses were conducted weekly to characterize the delivered raw material as well as the solid and liquid phase of the digestate in order to determine critical moments due to recirculation of process water. In conclusion, liquid and solid phase of the digestate should be evaluated with regards to application as fertilizer.
Y. Jani; R. Mutafela; L. Ferrans; G. Ling; J. Burlakovs; W. Hogland
Abstract
Dredging activities are necessary to maintain the navigation depth of harbors and channels. Additionally, dredging can prevent the loss of water bodies. A large amount of extracted sediments is produced around the world. Removed material is widely disposed at open seas or landfills. Much of the dredged ...
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Dredging activities are necessary to maintain the navigation depth of harbors and channels. Additionally, dredging can prevent the loss of water bodies. A large amount of extracted sediments is produced around the world. Removed material is widely disposed at open seas or landfills. Much of the dredged material is polluted and is classified as unsuitable for open-sea disposal. In Sweden, many dredging activities are taking place nowadays like that in Oskarshamn harbor, Inre harbor Norrköping municipality and Malmfjärden bay in Kalmar. In this review, the potential of phytoremediation as a treatment method is discussed with focus on suggested methods for reusing the treated sediments. Recycling or reusing of dredged and treated sediments will preserve Earth natural resources as well as reduce diffusion of contaminants to the environment.
I. A. Kebria; W. Hogland
Abstract
Analysis of urban climate changing is the basis for the implementation of storm water management measurements. Climate tensions such as changing precipitation patterns, fluctuations in temperature, and extreme events are already affecting water resources. For instance, precipitation pattern will be changed ...
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Analysis of urban climate changing is the basis for the implementation of storm water management measurements. Climate tensions such as changing precipitation patterns, fluctuations in temperature, and extreme events are already affecting water resources. For instance, precipitation pattern will be changed due to more water vapor in the atmosphere. Hence, it will not be evenly distributed. Some places will see more rain, others will get less snow. However, climate changes, such as the amount, timing, and intensity of rain events, in combination with land development, can significantly affect the amount of storm water runoff that needs to be managed. Firstly, this essay will be discussed about the prediction of climate change using a fuzzy neural network (FNN) and it shows the accuracy of this method for anticipating storm water. Secondly, based on the results of the first phase, it determines the critical area for preparing storm water systems with the application of GIS tools and technology.