Method for remediating industrial wastewater

Abstract

Disclosed herein is a method for remediating a stored liquid waste by reducing a content of a species capable of being bacterially degraded under anaerobic conditions, the stored liquid waste having bulk properties incompatible with anaerobic biodegradation. The method comprises the following steps (a) and (b), which are repeated until the stored liquid waste has bulk properties compatible with anaerobic biodegradation and contains an amount of the microorganism effective to sustain biodegradation of the species in the stored liquid waste: (a) removing an aliquot of the liquid waste and treating the aliquot by exposing to conditions whereby the species is anaerobically biodegraded by a microorganism capable of biodegrading the species; and (b) returning the treated aliquot back to the stored liquid waste, whereby the bulk properties of the stored liquid waste become more conducive to anaerobic biodegradation.

Description

technical field [0001] The present invention relates to a method for reconditioning stored waste liquids under anaerobic conditions. In some forms, the invention relates to methods for remediating holding ponds containing industrial wastewater produced by alumina refineries. Background technique [0002] Invented by Carl Josef Bayer in 1887, the Bayer process has become the production of alumina (Al 2 o 3 ) of the main industrial methods. The Bayer process starts with bauxite ore being crushed, washed and then dried. After drying, the crushed ore is dissolved in caustic soda at high temperature and then filtered to remove impurities. [0003] The resulting sodium aluminate (NaAl(OH) 4 ) solution is transferred to the settling tank, in the settling tank with the cooling of the hot solution, aluminum hydroxide (Al(OH 3 ) seeds stimulate the formation of aluminum hydroxide crystals. Aluminum hydroxide crystals accumulate at the bottom of the settling tank where they are ...

AI Technical Summary

Problems solved by technology

Aerobic bioreactor treatment plants have been used by industry to treat separated dissolved oxalate waste streams but have experienced a number of challenges including frequent failure of mechanical components, failure of pump seals due to deposition of aluminum hydrate particles , accumulation of aluminum hydrate and other materials in mechanical diffusers and aerators, deposition of aluminum hydrate on the reactor floor, which requires extensive maintenance to remove, and handling of aluminum hydrate-rich biomass

These limitations prevent widespread use of aerobic pathways for oxalate degradation in alumina refineries

Anaerobic biodegradation has been used to treat some types of wastewater, but the characteristics of wastewater in storage tanks containing oxalate are too harsh for biological activity, mainly because of their high (typically >13) pH

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