Desulfurization wastewater softening and membrane concentration method

Abstract

The invention relates to a desulfurization wastewater softening and membrane concentration method. The method comprises the following steps: pumping desulfurization wastewater into a raw water tank for storage and water quantity adjustment; carrying out microfiltration on the wastewater; enabling the filtered produced water to flow into a dosing settling tank, and adding a combined organic medicament into the dosing settling tank so as to soften the water quality of the produced water in the dosing settling tank; discharging the bottom mud in the dosing tank, and carrying out vacuum filter pressing on the bottom mud; pumping the supernate into a buffer tank; filtering water discharged from the buffer tank; adding a scale inhibitor into the filtered pipeline and mixing; and pumping the mixed solution into a nanofiltration membrane for filtering to obtain produced water and concentrated water of the nanofiltration membrane. The desulfurization wastewater softening and membrane concentration method disclosed by the invention has the advantages that calcium ions are complexed and precipitated, the removal rate of magnesium ions is relatively low, the magnesium ions and chloride ions and sulfate ions in the wastewater are not precipitated under an acidic condition, and the membrane is not polluted and blocked, so that a large amount of dosing cost can be reduced.

Description

technical field [0001] The invention belongs to the technical field of wastewater treatment, and in particular relates to a desulfurization wastewater softening and membrane concentration method. Background technique [0002] Limestone-gypsum wet flue gas desulfurization technology is currently the most widely used desulfurization technology for coal-fired power plants with mature technology, stable indicators, and wet flue gas desulfurization wastewater has the characteristics of high salt content, strong corrosion, and high hardness. With the increasingly stringent requirements on the discharge of desulfurization wastewater, the demand for zero discharge of desulfurization wastewater is also becoming more and more urgent. At present, there are two main problems encountered in technology: one is how to deal with the miscellaneous salts produced, and the other is that the energy consumption of operation is too high when the water volume is too large. The use of nanofiltrati...

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Problems solved by technology

[0004] In order to solve all or part of the above problems, the purpose of the present invention is to provide a desulfurization wastewater softening and membrane concentration method to reduce the consumption of a large amount of chemicals when using nanofiltration membranes to concentrate wastewater for magnesium and calcium removal, resulting in increased operating costs. technical issues

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