Method for treating waste water containing acid and ammonia

Abstract

The invention relates to an energy-saving type two-tower stripping method for treating waste water containing acid gas and ammonia, which belongs to the technical field of waste water treatment. The method comprises the following steps of: dividing the waste water which is to be treated and contains acid and ammonia into a cold part and a hot part, and respectively introducing the cold part and the hot part into a deacidification tower from the upper part and the middle upper part of the deacidification tower of a stripping type waste water treatment device, wherein acid gas is introduced into an acid recoverer after being stripped from the top of the deacidification tower; collecting kettle liquid waste water from the bottom of the deacidification tower; introducing the kettle liquid waste water into a deamination tower from the middle upper part of the deamination tower so that ammoniac steam is stripped from the top of the deamination tower; meanwhile, collecting kettle liquid from the bottom of the deamination tower. The heat used by a tower kettle reboiler is derived from the ammoniac steam extracted from the deamination tower; the sulfur residue quantity of the treated waste water is lower than 50mg / L, and the total ammonia content is lower than 100mg / L; and the method provided by the invention has the advantages of simple and easily controlled process, mature technology, low processing cost and energy saving and can be widely applied to various occasions for treating the waste water containing acid and ammonia.

Description

Technical field: [0001] The invention belongs to the technical field of wastewater treatment and utilization, and relates to a method for treating wastewater containing acid gas and ammonia, in particular to an energy-saving double-tower stripping method for treating wastewater containing acid gas and ammonia. Background technique: [0002] In the existing oil refining and coal chemical production process, a large amount of waste water containing acid gas (including carbon dioxide, hydrogen sulfide, etc.) and ammonia is often produced. To treat and reuse these waste water, it is necessary to separate the acid gas and Ammonia can only enter subsequent treatment devices or be reused. Steam stripping is the main common technical method for removing acid gas and ammonia in the current industrial process. Generally, there are technical processes such as single-tower stripping, double-tower stripping and single-tower stripping with side lines. Among them, double-tower stripping A...

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Problems solved by technology

Steam stripping is the main common technical method for removing acid gas and ammonia in the current industrial process. Generally, there are technical processes such as single-tower stripping, double-tower stripping and single-tower stripping with side lines. Among them, double-tower stripping And the single-tower stripping process with side line can obtain relatively pure acid gas and ammonia, which is a widely used technical process at present, and these existing stripping processes all use fresh steam as the top heat source, and the energy consumption is relatively high. High, generally 190-300 kg of steam is needed to treat one ton of waste water; the inventor once declared in 2008 the patent of "a method for treating phenolic and ammonia-containing coal chemical waste water by steam stripping with two towers" (Chinese patent number 200810106916.X ) technology has improved the original technology and proposed a more novel technical process route for treating acid gas and ammonia-containing wastewater. However, after nearly three years of practice and industrial operation, it was found that these existing processes have technical conditions It is not easy to control, and the high pressure and temperature will easily cause energy loss and other shortcomings. Therefore, it is proposed to design and invent a double stripping process with stable process operation, easy control of conditions and energy saving to treat acid and ammonia-containing wastewater, which can effectively improve At present, the high cost of acid gas and ammonia waste water treatment technology can meet the needs of the new energy-saving and emission-reduction standards of enterprises, and better realize the industrial application of the technology and have good anti-pollution benefits.

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