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Prague, Czech Republic

Czech University of Life science Prague ; is a university of agricultural education and research in Prague, the Czech Republic, established in 1906. Wikipedia.

Vymazal J.,Czech University of Life Sciences
Environmental Science and Technology | Year: 2011

The first experiments on the use of wetland plants to treat wastewaters were carried out in the early 1950s by Dr. Käthe Seidel in Germany and the first full-scale systems were put into operation during the late 1960s. Since then, the subsurface systems have been commonly used in Europe while free water surface systems have been more popular in North America and Australia. During the 1970s and 1980s, the information on constructed wetland technology spread slowly. But since the 1990s the technology has become international, facilitated by exchange among scientists and researchers around the world. Because of the need for more effective removal of ammonia and total nitrogen, during the 1990s and 2000s vertical and horizontal flow constructed wetlands were combined to complement each other to achieve higher treatment efficiency. Today, constructed wetlands are recognized as a reliable wastewater treatment technology and they represent a suitable solution for the treatment of many types of wastewater. © 2010 American Chemical Society. Source

Vymazal J.,Czech University of Life Sciences
Ecological Engineering | Year: 2014

Constructed wetlands have been used for wastewater treatment for more than fifty years. Most applications have been designed to treat municipal or domestic wastewater but at present, constructed wetlands are successfully applied to many types of wastewater. The early constructed wetlands applied to industrial wastewaters included those for wastewaters from petrochemical, abattoir, meat processing, dairy and pulp and paper industries. During the 1990s constructed wetlands were also used to treat effluents from textile and wine industries or water from recirculating fish and shrimp aquacultures. The most recent applications include those for brewery or tannery wastewaters as well as olive mills effluents. The survey revealed that both subsurface and surface flow constructed wetlands have been used for treatment of industrial wastewaters. Within subsurface flow constructed wetlands both horizontal and vertical flow systems have been designed. Also, the use of various hybrid constructed wetlands for industrial effluent treatment has been reported in the literature recently. The survey also revealed that industrial wastewaters are treated in constructed wetlands in all continents and this paper includes the information from 138 constructed wetlands in 33 countries worldwide. © 2014 Elsevier B.V. Source

The hybrid systems were developed in the 1960s but their use increased only during the late 1990s and in the 2000s mostly because of more stringent discharge limits for nitrogen and also more complex wastewaters treated in constructed wetlands (CWs). The early hybrid CWs consisted of several stages of vertical flow (VF) followed by several stages of horizontal flow (HF) beds. During the 1990s, HF-VF and VF-HF hybrid systems were introduced. However, to achieve higher removal of total nitrogen or to treat more complex industrial and agricultural wastewaters other types of hybrid constructed wetlands including free water surface (FWS) CWs and multistage CWs have recently been used as well. The survey of 60 hybrid constructed wetlands from 24 countries reported after 2003 revealed that hybrid constructed wetlands are primarily used on Europe and in Asia while in other continents their use is limited. The most commonly used hybrid system is a VF-HF constructed wetland which has been used for treatment of both sewage and industrial wastewaters. On the other hand, the use of a HF-VF system has been reported only for treatment of municipal sewage. Out of 60 surveyed hybrid systems, 38 have been designed to treat municipal sewage while 22 hybrid systems were designed to treat various industrial and agricultural wastewaters. The more detailed analysis revealed that VF-HF hybrid constructed wetlands are slightly more efficient in ammonia removal than hybrid systems with FWS CWs, HF-VF systems or multistage VF and HF hybrid CWs. All types of hybrid CWs are comparable with single VF CWs in terms of NH4-N removal rates. On the other hand, CWs with FWS units remove substantially more total nitrogen as compared to other types of hybrid constructed wetlands. However, all types of hybrid constructed wetlands are more efficient in total nitrogen removal than single HF or VF constructed wetlands. © 2013 Elsevier Ltd. Source

Hanc A.,Czech University of Life Sciences
Bioresource technology | Year: 2012

The study was focused on evaluation of possible changes in As, Cr, and Ni mobility and fractionation during composting of kitchen and garden waste. Fresh bio-waste taken up seasonally was thoroughly mixed with woodchips in the wet weight portion of 3:1 and the mixture was put into batch-wise aerated fermenters under 3 air flow rates. An increased drop in exchangeable Cr and Ni was found in kitchen and garden waste after 12 weeks of composting, respectively. The exchangeable content of As decreased only during kitchen waste composting. The order of fractions in the final compost was as follows: residual>oxidizable>exchangeable>reducible. The proportion of Cr and Ni in exchangeable fraction decreased after composting more than 3- and 4-fold, respectively. Results proved that an intensive composting process is a suitable method for immobilization of Cr and Ni, and for decreasing total As contained in household bio-waste. Copyright © 2011 Elsevier Ltd. All rights reserved. Source

Muller M.,Czech University of Life Sciences
Agronomy Research | Year: 2013

An adhesive bonding technology is a prospective bonding technology of diverse materials. Namely the research in the sphere of the degradation aspects affecting the adhesive bond during the technical life of the adhesive bonded complex is essential. Mineral and industrial fertilisers can be included as significant degradation agents. The aim of the research was to find out the relevant knowledge in the sphere of the degradation of the adhesive bonds placed in the water bath, the oil bath and the solution of the mineral and industrial fertilisers. The experiment's results bring knowledge for producers of agricultural machines introducing adhesive bonding technology into their production programme. Two- component constructional epoxy adhesives were tested which were placed into the water bath, the oil bath and the solution of mineral and industrial fertilisers. Some agents caused such changes in the adhesive that the adhesive bond strength decreased to zero value already after 90 days. Significant changes of the adhesive bond strength occurred in the interval 15-45 days depending on the adhesive and agents. The strength decrease was connected with the change of a failure area from cohesive one to combined and then to adhesive one. The research showed that it came to diffuse seepage and to a partial corrosion of the adhesive bonded steel samples. Source

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