Firdha, IrenaAhmad, AdriantoAmraini, Said Zul2014-02-052014-02-052014-02-05978-602-96729-0-9wahyu sari yenihttps://repository.unri.ac.id/handle/123456789/5492Industrial palm oil waste water has increased along with growth the palm oil industry in the Indonesia; Industrial palm oil waste water is a very dangerous organic poUutants. In conllentionoJ wastewater treatment with anaerobic pond. microorganisms capable of degrading organic compounds from wastewater in a long time. For this case operation of an anaerobic hybrid bioreactor with the stone be the media expected to increase the ability of microorganisms to degrade organic material. The purpose of this mldy are to assess and study the hydraulic residence time of substrate to reduce COD Industrial palm oil waste water in anaerobic hybrid bioreactor. Research carried out by a few variations ofWTll. i.e. I, 2. 3. and 4 day. Each WIH'operateduntil steady state was obtained based on COD data. Results showed that WTll· offect COD removal efficiency. that are concentration of COD of 80% on WIll 1 day, 82% on WTH 2 day. 88% on Wl1l 3 day, and 90% in WTH 4 dtJy. So, designed a hybrid bioreactor with the stone be the media system lhnt utilkes the ability maintain the biomass can be realized; so the ejfort to; build a technology that is used to treat wastewater effectively and efficiently can be applied.enAnaerobHldrolic retention timeHybrid bioreactorReduce CODUR-Scientific Work Lecturer