Treatment method for reverse osmosis concentrated water

Abstract

The invention relates to a treatment method for reverse osmosis concentrated water. Aiming at reverse osmosis concentrated water generated by a reverse osmosis process of a double-membrane process, the method comprises: firstly removing organic matters and scaling ions such as calcium, magnesium and the like in the reverse osmosis concentrated water by using a nanofiltration membrane, then feeding the nanfiltration contributing water into the reverse osmosis system to be further concentrated, and then feeding the concentrated nanfiltration contributing water into a membrane distillation system for treatment and recycling; and adding alkali into the concentrated water generated by the nanfiltration system to remove scaling ions such as calcium, magnesium and the like and part of organic matters and adsorbing the substances through powdery active carbon to discharge the up-to-standard concentrated water. According to the treatment method for reverse osmosis concentrated water provided by the invention, the organic matters and scaling ions such as calcium, magnesium and the like which cause pollution to a subsequent reverse osmosis membrane are removed by virtue of a nanofiltration technology firstly, so that the stable operation of the reverse osmosis system is ensured; then the nanofiltration contributing water is further concentrated by virtue of the reverse osmosis system, so that the water inflow of membrane distillation is greatly reduced, the recovery rate of the reverse osmosis concentrated water is improved, and the treatment cost for the reverse osmosis concentrated water is lowered. The treatment method has good economical and social benefits.

Description

technical field [0001] The invention relates to a method for treating sewage, in particular to a method for treating reverse osmosis concentrated water, especially a method for treating reverse osmosis concentrated water for reuse. The reverse osmosis concentrated water is the reverse osmosis concentrated water produced by the reverse osmosis process in the double-membrane process. Background technique [0002] Due to its simple process, convenient operation, and small footprint, the double-membrane process is widely used in the advanced treatment and reuse of industrial wastewater. However, while the reverse osmosis process in the double-membrane process produces pure recycled water, it also produces concentrated water with a high concentration of pollutants (that is, reverse osmosis concentrated water), and the amount of reverse osmosis concentrated water usually accounts for 50% of the recycled water. One-third, therefore, the treatment and discharge of reverse osmosis c...

AI Technical Summary

Problems solved by technology

[0005] ② Poor biodegradability, the main pollutants are some high-level aliphatic hydrocarbons, polycyclic aromatic hydrocarbons, polycyclic aromatic compounds and other refractory organic substances;

[0007] ④High salt content

[0013] Patents CN102139984A and CN103373786A adopt membrane distillation process, and use temperature difference to treat reverse osmosis concentrated water under normal pressure to obtain pure water, but the required economic cost is relatively high