Search Results - chul+park

Water and wastewater treatments consume 3-4% of energy, while 60% of energy used at the wastewater treatment plant is dedicated to aeration in the activated sludge process. This novel bio-granule called oxygenic bio-granule, proposes to transform wastewater treatment facilities into water resource recovery facilities. The oxygenic bio-granule results from the conversion of activated sludge under photochemical reactions. It is naturally formed and is composed of algae and bacteria within one granular biomass. The bio-granule is a dense, spherical aggregate of microorganisms that is a self-immobilized biofilm and forms in the absence of solid substratum. The cohabitation of algae and bacteria within the biogranule allows for an efficient symbiotic wastewater treatment process. The bacteria degrade organic matter utilizing O2 that is produced by the algae. In addition, the algae harvest CO2 produced from the organic matter degradation for photosynthesis. The biomass flocculates to be 0.2 to 10mm in size, which allows them to be easily separable from water.

Treatment and disposal of bio-hazardous sludge accounts for 50-60% of the operational costs at a wastewater treatment plant. To treat this sludge, it undergoes a process involving thickening, conditioning, and dewatering, followed by transport to a landfill or incinerator. In addition to high costs, landfilling and incineration are detrimental from a sustainability standpoint.

 

In this patented invention, a closed, anaerobic, completely stirred tank side stream reactor is added after the outlet of the settling tank at the wastewater treatment plant. Solids retention time in the reactor is short (< 4 days), keeping its size and cost down. The acidic and anaerobic environment of the reactor causes biomass to deflocculate and sludge to hydrolyze, ultimately reducing sludge by 60%. The invention also has the added benefit of producing hydrogen and methane fuel.