Experimental study on anaerobic digestion of rice mill waste water

Abstract

newlineFossil fuels play a vital role in today s energy sector. However, newlinefossil fuel reserves are depleting at an alarmingly rapid rate and their newlineextensive use is contributing to undesirable global climate changes. Depletion newlineof fuel resources is being realised as a major global issue. At this critical point newlinein time, alternate energy sources are highly sought after by almost all nations newlineto meet the increasing energy demands and solve the daunting energy newlinechallenges that await humanity in the near future. Due to their environmental newlinebenefits, renewable energy sources like solar energy, wind energy, energy newlinefrom biomass and biofuels are used as substitutes for fossil fuels. Among the newlinevarious renewable energy sources, biomass-based energy sources like biogas, newlinebiodiesel and bioethanol are gaining wide popularity due to its high energy newlinepotential and abundant availability. Third-generation biofuels like microalgae oil have higher calorific values and they can be used in the fossil-fuelled engines directly. Scientists newlineare even more interested in the production of biogas using anaerobic digestion newlineof organic materials. The present study aimed to employ anaerobic digestion newlineto produce biogas from Rice Mill Wastewater (RMW) and to use anaerobic newlinedigestate (liquid and solid digestate generated from anaerobic digester) as a newlinesubstrate for growing algae for biodiesel production. The anaerobic digester newlinecontaining RMW and distillery anaerobic sludge in the ratio of 3: 1 ratio was newlinekept at mesophilic temperature to attain the state of stabilization, subsequently newlineto produce biogas. In this study RMW was used as substrate and distillery newlineanaerobic sludge was used as seed for biogas production. newlineHerein, anaerobic digestion was carried out in three different newlineoperating conditions of varying the organic loading rate (OLR) from 0.26 to newline4.43 kg COD/m3/day and the hydraulic retention time (HRT) was kept newlineconstant at a one day (operating condition I), HRT was varied from 2 to 34 newlinedays and the OLR was kept constant at 2.5 kg COD/m3/day (operating newlinecondition I