Membrane technology revolutionizes water treatment

2007 ◽  
Vol 55 (7) ◽  
pp. 11-20 ◽  
Author(s):  
P.A. Wilderer ◽  
S. Paris
Keyword(s):  
Millennium Development Goals ◽  
Ambient Conditions ◽  
Water And Wastewater Treatment ◽  
Natural Systems ◽  
Selective Transport ◽  
Small Water ◽  
Development Goals ◽  
Water And Wastewater ◽  
Technical Solutions ◽  
Efficiency And Reliability

Membranes play a crucial role in living cells, plants and animals. They not only serve as barriers between the inside and outside world of cells and organs. More importantly, they are means of selective transport of materials and host for biochemical conversion. Natural membrane systems have demonstrated efficiency and reliability for millions of years and it is remarkable that most of these systems are small, efficient and highly reliable even under rapidly changing ambient conditions. Thus, it appears to be advisable for technology developers to keep a close eye on Mother Nature. By doing so it is most likely that ideas for novel technical solutions are born. Following the concept of natural systems it is hypothesized that the Millennium Development Goals can be best met when counting on small water and wastewater treatment systems. The core of such systems could be membranes in which chemical reactions are integrated allowing recovery and direct utilization of valuable substances.

scholarly journals Application of Polymer Inclusion Membranes Doped with Alkylimidazole to Separation of Silver and Zinc Ions from Model Solutions and after Battery Leaching

Materials ◽  
2020 ◽  
Vol 13 (14) ◽  
pp. 3103 ◽  
Author(s):  
Elzbieta Radzyminska-Lenarcik ◽  
Malgorzata Ulewicz ◽  
Ilona Pyszka
Keyword(s):  
Silver Oxide ◽  
Cellulose Triacetate ◽  
Water And Wastewater Treatment ◽  
Force Microscopy ◽  
Selective Transport ◽  
Atomic Force ◽  
Model Solutions ◽  
Leaching Solution ◽  
Water And Wastewater ◽  
Nitrate Solutions

New materials, such as polymer inclusion membranes, can be used for water and wastewater treatment. In this paper, the selective transport of silver(I) and zinc(II) ions from nitrate solutions through the polymer inclusion membranes (PIMs), which consist of cellulose triacetate as a polymeric support, o-nitrophenyl pentyl ether as a plasticizer, and either 1-hexylimidazole (1) or 1-hexyl-2-methylimidazole (2) as an ion carrier, is studied. Both Zn(II) and Ag(I) model solutions (CM = 0.001 M, pH = 6.5), as well as the solutions after the leaching of a spent battery with a silver–zinc cell (silver-oxide battery), are tested. The results show that Zn(II) ions are effectively transported through PIMs containing either carrier, whereas Ag(I) is more easily transported through PIMs doped with (1). In the case of the leaching solution after 24 h transport, the recovery coefficients of Ag(I) and Zn(II) for PIMs doped with (1) are 86% and 90%, respectively, and for PIMs doped with (2), 47% and 94%, respectively. The influence of basicity and structure of carrier molecules on transport kinetics is discussed as well. PIMs are characterized by using an atomic force microscopy (AFM) technique.

Sludge management of small water and wastewater treatment plants

2004 ◽  
Vol 48 (11-12) ◽  
pp. 33-41 ◽  
Author(s):  
O. Nowak ◽  
V. Kuehn ◽  
M. Zessner
Keyword(s):  
Wastewater Treatment ◽  
Water Treatment ◽  
Wastewater Treatment Plants ◽  
Advanced Treatment ◽  
Economic Pressure ◽  
Water And Wastewater Treatment ◽  
Sludge Treatment ◽  
Small Water ◽  
Water Treatment Plants ◽  
Water And Wastewater

“Disposal or reuse?” is the big question in respect to sewage and water sludges. This question is even more decisive for small plants, because the achievement of the advanced treatment necessary for disposal is much more difficult in small units than in big ones. The paper discusses this question with main focus on small WWTPs and gives a short overview of the specifics of sludge treatment in small units as well as of outlets for sludge from water treatment plants. In general, small WWTPs do not have a better sludge quality than larger ones, but the economic pressure to realise reuse is higher on them than on large plants.

On the use of crushed shells of apricot stones as the upper layer in dual media filters

2004 ◽  
Vol 48 (11-12) ◽  
pp. 497-503 ◽  
Author(s):  
S. Aksoğan ◽  
A. Baştürk ◽  
E. Yüksel ◽  
Ö Akgiray
Keyword(s):  
Wastewater Treatment ◽  
Silica Sand ◽  
Water And Wastewater Treatment ◽  
Turbidity Removal ◽  
Small Water ◽  
Anthracite Coal ◽  
The World ◽  
Water And Wastewater ◽  
Removal Efficiencies ◽  
Wastewater Treatment Systems

The use of crushed shells of apricot stones instead of anthracite coal in dual-media filters is investigated. Turbidity removal efficiencies were measured for several filtration rates in dual media filters composed of shells of apricot stones above silica sand and anthracite coal above silica sand. Backwash (fluidization) experiments were carried out using sieved fractions of crushed shells of apricot stones to establish curves of expansion versus backwash velocity at 25°C. Such curves can be used in the design of filters employing this material. It is believed that the use of such a locally available and cheaper alternative filter medium would be of interest in many small water and wastewater treatment systems around the world.

Achieving the Millennium Development Goals

The Lancet ◽  
2005 ◽  
Vol 365 (9464) ◽  
pp. 1030-1030
Author(s):  
D HOLDSTOCK ◽  
M ROWSON
Keyword(s):  
Millennium Development Goals ◽  
Development Goals
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