Boric acid, as an important boron compound, has been widely used in industrial production and cutting-edge technology. Massive wastewater containing boron were discharged during the industrial process. Adsorption technique is an efficient method for removal or recovery of boron from aqueous solutions as it has advantages of high boron recovery, renewable adsorbents and easy operation. The key to the adsorption process is the the selection of adsorbents with high adsorption capacity, acceptable mechanical strength and regeneration capability. In this review, we mainly review different kinds of boron-selective adsorbents reported in recent years and their adsorption performances. Boron adsorbents are catalogued by their functional groups. Among the reported adsorbents, the most widely used N-methyl-D-glucamine (NMDG) functionalized adsorbents are extensively demonstrated, and the adsorbents with structure of diols binding phenolic moiety are discussed. Moreover, other organic-inorganic hybrid adsorbents are introduced. This review may be helpful to the design of novel high-performance adsorbents for boron recovery or removal from aqueous solutions such as from salt lake brine and desalinize seawater.

Contents
1 Introduction
2 NMDG functionalized adsorbents
2.1 NMDG functionalized organic resins
2.2 NMDG functionalized organic-inorganic hybrid materials
3 Other active diols functionalized adsorbents
3.1 Polymeric adsorbents
3.2 Phenolic adsorbents
4 Inorganic adsorbents
4.1 Magnesium hydroxide
4.2 Hydroxide of aluminum, iron, calcium
5 Natural adsorbents
6 Conclusion and outlook