Preparation of Solutions of Titanium Trichloride-Based Complex Coagulants

Author(s):  
E.N. Kuzin

One of the largest sources of heavy metal compounds entering the hydrosphere is galvanic production. Despite their high danger, chromium (VI) compounds are widely used in electroplating. Electrolytes based on chromium (VI) compounds are stable at all pH values and, if released into water, pose a serious problem for wastewater treatment plants. The purpose of this study was to assess the possibility of thermal and electrochemical preparation of solutions of complex coagulants-reducing agents based on titanium trichloride for wastewater treatment from chromium (VI) compounds. Findings of research show that the yield of titanium trichloride is practically independent of the production method, however, the process of electrochemical synthesis is much more stable, the reaction mixture is slightly heated, which has a positive effect on the storage time of the obtained reagent solutions. The study proves that in terms of their effectiveness, the samples of the complex coagulant-reducing agent are superior to individual reagents based on iron (II) compounds. Moreover, the use of complex reagents makes it possible to considerably intensify the processes of sedimentation and filtration of the resulting sludge, which allows us to significantly reduce the dimensions of the equipment and increase the economic efficiency of the water purification process as a whole

2012 ◽  
Vol 65 (9) ◽  
pp. 1654-1659 ◽  
Author(s):  
S. Lyko ◽  
B. Teichgräber ◽  
A. Kraft

Sludge bulking is still a problem in the operation of state-of-the-art wastewater treatment plants (WWTPs). The ozonation of returned activated sludge (RAS) is an innovative option as a non-specific measure for the control of filament growth. The applicability of sludge ozonation for bulking control of a large wastewater treatment plant was investigated. At a full-scale WWTP one lane was equipped with a sludge ozonation plant for RAS. The implemented sludge ozonation of RAS was tested against the two identical references lanes of the same WWTP. The positive effect on settleability could be clearly proven. Low-dose sludge ozonation could be a technical alternative in comparison with the established chemical measures for bulking control.


2020 ◽  
Vol 15 (2) ◽  
pp. 142-151
Author(s):  
Peter Lukac ◽  
Lubos Jurik

Abstract:Phosphorus is a major substance that is needed especially for agricultural production or for the industry. At the same time it is an important component of wastewater. At present, the waste management priority is recycling and this requirement is also transferred to wastewater treatment plants. Substances in wastewater can be recovered and utilized. In Europe (in Germany and Austria already legally binding), access to phosphorus-containing sewage treatment is changing. This paper dealt with the issue of phosphorus on the sewage treatment plant in Nitra. There are several industrial areas in Nitra where record major producers in phosphorus production in sewage. The new wastewater treatment plant is built as a mechanicalbiological wastewater treatment plant with simultaneous nitrification and denitrification, sludge regeneration, an anaerobic zone for biological phosphorus removal at the beginning of the process and chemical phosphorus precipitation. The sludge management is anaerobic sludge stabilization with heating and mechanical dewatering of stabilized sludge and gas management. The aim of the work was to document the phosphorus balance in all parts of the wastewater treatment plant - from the inflow of raw water to the outflow of purified water and the production of excess sludge. Balancing quantities in the wastewater treatment plant treatment processes provide information where efficient phosphorus recovery could be possible. The mean daily value of P tot is approximately 122.3 kg/day of these two sources. The mean daily value of P tot is approximately 122.3 kg/day of these two sources. There are also two outflows - drainage of cleaned water to the recipient - the river Nitra - 9.9 kg Ptot/day and Ptot content in sewage sludge - about 120.3 kg Ptot/day - total 130.2 kg Ptot/day.


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