scholarly journals Donnan Membrane Process for the Selective Recovery and Removal of Target Metal Ions—A Mini Review

Membranes ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 358
Author(s):  
Dennis Asante-Sackey ◽  
Sudesh Rathilal ◽  
Emmanuel Kweinor Tetteh ◽  
Elorm Obotey Ezugbe ◽  
Lingham V. Pillay

Membrane-based water purification technologies contribute significantly to water settings, where it is imperative to use low-cost energy sources to make the process economically and technically competitive for large-scale applications. Donnan membrane processes (DMPs) are driven by a potential gradient across an ion exchange membrane and have an advantage over fouling in conventional pressure driven membrane technologies, which are gaining attention. DMP is a removal, recovery and recycling technology that is commonly used for separation, purification and the concentrating of metals in different water and waste streams. In this study, the principle and application of DMP for sustainable wastewater treatment and prospects of chemical remediation are reviewed and discussed. In addition, the separation of dissolved metal ions in wastewater settings without the use of pressure driven gradients or external energy supply membrane technologies is highlighted. Furthermore, DMP distinctive configurations and operational factors are explored and the prospects of integrating them into the wastewater treatment plants are recommended.

Polymers ◽  
2019 ◽  
Vol 11 (9) ◽  
pp. 1449 ◽  
Author(s):  
Roy Zamora-Sequeira ◽  
Fernando Alvarado-Hidalgo ◽  
Diana Robles-Chaves ◽  
Giovanni Sáenz-Arce ◽  
Esteban Avendano-Soto ◽  
...  

Mancozeb is a worldwide fungicide used on a large scale in agriculture. The active component and its main metabolite, ethylene thiourea, has been related to health issues. Robust, fast, and reliable methodologies to quantify its presence in water are of great importance for environmental and health reasons. The electrochemical evaluation of mancozeb using a low-cost electrochemical electrode modified with poly (3,4-ethylene dioxythiophene), multi-walled carbon nanotubes, and gold nanoparticles is a novel strategy to provide an in-situ response for water pollution from agriculture. Additionally, the thermal-, electrochemical-, and photo-degradation of mancozeb and the production of ethylene thiourea under controlled conditions were evaluated in this research. The mancozeb solutions were characterized by electrochemical oxidation and ultraviolet-visible spectrophotometry, and the ethylene thiourea concentration was measured using ultra-high-performance liquid chromatography high-resolution mass spectrometry. The degradation study of mancozeb may provide routes for treatment in wastewater treatment plants. Therefore, a low-cost electrochemical electrode was fabricated to detect mancozeb in water with a robust electrochemical response in the linear range as well as a quick response at a reduced volume. Hence, our novel modified electrode provides a potential technique to be used in environmental monitoring for pesticide detection.


1990 ◽  
Vol 22 (3-4) ◽  
pp. 291-298
Author(s):  
Frits A. Fastenau ◽  
Jaap H. J. M. van der Graaf ◽  
Gerard Martijnse

More than 95 % of the total housing stock in the Netherlands is connected to central sewerage systems and in most cases the wastewater is treated biologically. As connection to central sewerage systems has reached its economic limits, interest in on-site treatment of the domestic wastewater of the remaining premises is increasing. A large scale research programme into on-site wastewater treatment up to population equivalents of 200 persons has therefore been initiated by the Dutch Ministry of Housing, Physical Planning and Environment. Intensive field-research work did establish that the technological features of most on-site biological treatment systems were satisfactory. A large scale implementation of these systems is however obstructed in different extents by problems of an organisational, financial and/or juridical nature and management difficulties. At present research is carried out to identify these bottlenecks and to analyse possible solutions. Some preliminary results are given which involve the following ‘bottlenecks':-legislation: absence of co-ordination and absence of a definition of ‘surface water';-absence of subsidies;-ownership: divisions in task-setting of Municipalities and Waterboards; divisions involved with cost-sharing;-inspection; operational control and maintenance; organisation of management;-discharge permits;-pollution levy;-sludge disposal. Final decisions and practical elaboration of policies towards on-site treatment will have to be formulated in a broad discussion with all the authorities and interest groups involved.


2015 ◽  
Vol 15 (1) ◽  
pp. 61-66
Author(s):  
Ranjan Nepal ◽  
Raja Ram Pradhananga

Lead oxide-graphite composite electrode for pH measurement had been fabricated with different percentage of PbO2 in the composite. The proportions of lead oxide affected the sensitivity of the electrode. The electrode composed of 50% lead oxide and 50% graphite gave reproducible result and behaved in Nernstian manner with a potential gradient of -58.8±0.3 mV per unit change in pH. Metal ions such as iron (II), iron (III) and lead (II) interfered in the measurement of pH, while silver (I), copper (II), oxidizing agents such as dichromate and permanganate do not interfere. In absence of interfering ion, the lead oxide-graphite composite electrode could be used for the measurement of pH from 2 to 11. This electrode can also be used as an indicator electrode for acid base titrations. Low cost, quick response, easy to fabricate are some of the advantages of the lead oxide-graphite composite electrode. This electrode is also found to be sensitive to Pb2+ -ions and can be used as a Pb2+-ion sensor up to 10-4M.DOI: http://dx.doi.org/10.3126/njst.v15i1.12015  Nepal Journal of Science and TechnologyVol. 15, No.1 (2014) 61-66


2001 ◽  
Vol 44 (1) ◽  
pp. 105-112 ◽  
Author(s):  
M. Burde ◽  
F. Rolf ◽  
F. Grabowski

The absence of large rivers with rather high niveau of self purifying effect in parts of east Germany leads to a discharging of the effluent of wastewater treatment plants into the groundwater in many cases. One useful consequence is the idea of realisation of decentralised measures and concepts in urban water resources management concerning municipal wastewater as well as rainfall, precipitation. At the same time, only the upper soil zone - a few decimetres - is water - saturated and thus discharge effective, even when extreme rainfall takes place. Underneath, however, there generally exists an unsaturated soil zone, which is up to now a rather unexplored retardation element of the hydrologic- and substrate-cycle. Nutrient removal in small wastewater treatment plants that are emptying into ground waters is often beneficial. The presented studies optimised an inexpensive method of subsequent enhanced wastewater treatment. The developed reactor is similar to a concentrated subsoil passage. The fixed bed reactor is divided in two sections to achieve aerobic and anoxic conditions for nitrification/denitrification processes. To enhance phosphorus removal, ferrous particles are put into the aerobic zone. Two series of column tests were carried out and a technical pilot plant was built to verify the efficiency of the process. The results show that this method can be implemented successfully.


2011 ◽  
Vol 63 (4) ◽  
pp. 660-665 ◽  
Author(s):  
R. J. Craggs ◽  
S. Heubeck ◽  
T. J. Lundquist ◽  
J. R. Benemann

This paper examines the potential of algae biofuel production in conjunction with wastewater treatment. Current technology for algal wastewater treatment uses facultative ponds, however, these ponds have low productivity (∼10 tonnes/ha.y), are not amenable to cultivating single algal species, require chemical flocculation or other expensive processes for algal harvest, and do not provide consistent nutrient removal. Shallow, paddlewheel-mixed high rate algal ponds (HRAPs) have much higher productivities (∼30 tonnes/ha.y) and promote bioflocculation settling which may provide low-cost algal harvest. Moreover, HRAP algae are carbon-limited and daytime addition of CO2 has, under suitable climatic conditions, the potential to double production (to ∼60 tonnes/ha.y), improve bioflocculation algal harvest, and enhance wastewater nutrient removal. Algae biofuels (e.g. biogas, ethanol, biodiesel and crude bio-oil), could be produced from the algae harvested from wastewater HRAPs, The wastewater treatment function would cover the capital and operation costs of algal production, with biofuel and recovered nutrient fertilizer being by-products. Greenhouse gas abatement results from both the production of the biofuels and the savings in energy consumption compared to electromechanical treatment processes. However, to achieve these benefits, further research is required, particularly the large-scale demonstration of wastewater treatment HRAP algal production and harvest.


1995 ◽  
Vol 1 (3) ◽  
pp. 185-198 ◽  
Author(s):  
Imre Takacs ◽  
Gilles G Patry ◽  
Bruce watson ◽  
Bruce GALL

1994 ◽  
Vol 30 (2) ◽  
pp. 141-147 ◽  
Author(s):  
Bruce Watson ◽  
Mark Rupke ◽  
Imre Takács ◽  
Gilles Patry

Dynamic mathematical modelling of full-scale wastewater treatment plants requires an optimal level of detail to be accurate, effective, but still manageable. Single process models tend to oversimplify the complexities of a large-scale plant and result in erroneous calibrated parameter values or limited predictive power for the model – on the other hand, modelling of every process and process unit is usually impractical, since it cannot be supported by reliable plant data, and requires prohibitive sampling costs and effort. Level of aggregation, settler dimensionality and reactivity, and plug-flow hydraulics were investigated with the help of a sophisticated dynamic modelling package. The results show that there is no general rule or global ‘optimal level’ of modelling – the required modelling detail is a function of influent flow and loading levels, and processes to be simulated (BOD removal, nitrification-denitrification, biological phosphorus removal, settling). In the case of real-life plants, supportable modelling level is often constrained by data availability and reliability.


Author(s):  
Nancey Hafez

Enzymes are biocatalysts provided by cells and are used in most metabolic methods. Most enzymes are consisting of proteins containing tertiary amino acid which bind to co enzyme or metal ions. Enzymes are accelerating biochemical processes by some mechanisms to chemical catalysts e.g metals, metal oxides and metal ions. Enzymes can be very effective under conditions e.g (temperature, atmospheric pressure and PH). Many enzymes have hydrolyzing, oxidizing and reducing characters. Enzymatic reactions always provide less side effects reactions and fewer waste by products. That is why microbial Enzymes can give an effective and environmental safe alternatives as metabolic inorganic chemical catalysts which can be used in all over pharmaceutical industrial processes. Enzymes are used in waste water treatment. Treatment technologies depend on physico-chemical approaches in wastewater treatment plants which require skills, high operation costs (in terms of high energy and chemical demand). Wastewater treatment is operated to protect the quality of limited freshwater resources, which are most times the final discharge points of effluents, and also, to promote the reusability of expended clean water; amounts of hazardous aromatic byproducts are still generated [3, 4]. The observation shows that wastewater treatment plants, though liable to remove microcontaminants such as heavy metals, and to a far lesser extent, aromatic contaminants, were originally structured for the removal of solid wastes, ecofriendly organic matter and eutrophication stimulants from wastewater, thereby reducing eutrophicating pollution loads; the micropollutants may only be moderately affected by the chemical, physical and biological interactions within the treatment plants.


2002 ◽  
Vol 45 (4-5) ◽  
pp. 485-494 ◽  
Author(s):  
U. Jeppsson ◽  
J. Alex ◽  
M.N. Pons ◽  
H. Spanjers ◽  
P.A. Vanrolleghem

The status of instrumentation, control and automation (ICA) within the European wastewater community is reviewed and some major incentives and bottlenecks are defined. Future trends of ICA are also discussed. The information is based on a COST 624 workshop and a non-exhaustive survey with regard to ICA carried out in 13 European countries during March 2001. The level of instrumentation (type of sensors, usage frequency, etc.) and how these instruments are used for on-line control purposes are presented for each individual country (Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Netherlands, Romania, Slovenia, Spain, Sweden and Switzerland). The most common types of applied real-time control in wastewater treatment plants are given. One conclusion of the paper is that sensors no longer represent the main bottleneck for on-line control, rather the lack of plant flexibility is more troublesome. Moreover, the current transitional phase of the wastewater industry in Europe represents a unique opportunity to apply ICA on a large scale. The driving forces are simply too strong to ignore.


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