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We report the discovery of excess broad band absorption near 2250 A (EBBA) inthe spectra of seven broad absorption line (BAL) quasars. By comparing with thestatistical results from the control quasar sample, the significance for thedetections are all above the > 4{\sigma} level, with five above > 5{\sigma}.The detections have also been verified by several other independent methods.The EBBAs present broader and weaker bumps at smaller wavenumbers than theMilky Way, and similar to the Large Magellanic Cloud. The EBBA bump may berelated to the 2175 A bump seen in the Local Group and may be a counterpart ofthe 2175 A bump under different conditions in the early Universe. Furthermore,five objects in this sample show low-ionization broad absorption lines(LoBALs), such as Mg II and Al III, in addition to the high-ionization broadabsorption lines (HiBALs) of C IV and Si IV. The fraction of LoBALs in oursample, ~70%, is surprisingly high compared to that of general BAL quasars,~10%. Although the origin of the bump is still not clear, the coexistence ofboth BALs and bumps and the significantly high fraction of LoBALs may indicatethe bump carriers is closely related to the early evolution phase of quasars.

Seven broad absorption line quasars with excess broad band absorption near 2250 \AA