The invention relates to a preparation method and application of a modified orange peel biological adsorbent. The method comprises the steps that the orange peel
waste material is cleaned, dried, ground, screened, and refluxed with
epichlorohydrin in absolute ethyl
alcohol and NaOH solution, so the
epichlorohydrin cross-linking type orange peel is obtained; and the
epichlorohydrin cross-linking type orange peel is added with a catalyst and a modifier to be continuously stirred, after the reaction is completed, and the treated orange peel is cleaned and dried, so the
cysteine or
diethylene triamine modified orange peel biological adsorbent can be obtained. The adsorbent can effectively adsorb the heavy
metal ions of Cu<2+>, Pb<2+>, Ni<2+> and Zn<2+> in the
wastewater, the treatment cost is low, the efficiency is high, and the
treated water body can reach the national
wastewater discharge standard, so the purpose of treatment of wastes with another waste is realized. Moreover, the heavy
metal ions in the
wastewater can also be recovered, and the adsorbent has the characteristics of low cost,
reusability, simple preparation method and strong adsorption capability.