افزايش راندمان توليد بيوگاز در راكتور ناپيوسته با استفاده از تخمير پساب صنايع

چكيده انگليسي :

Enhancement of Biogas Production in Batch Reactor from Industrial Wastewater Hojatollah Sayedi Niasar h seyediniasar@ce iut ac ir September 27 2010 Department of Chemical Engineering Isfahan University of Technology Isfahan 84156 83111 Iran Degree M Sc Language Farsi Supervisor Hamid Zilouei Email hzilouei@cc iut ac ir Abstract In today s energy demanding life style need for exploring and exploiting new sources of energy which are renewable as well as eco friendly is necessary Among the renewable energy technologies like waterfall solar wind etc biogas production from industrial wastes has been of interest as a renewable source of energy in recent decades Biogas is the gas produced by methanogenics bacteria while acting upon degradable organic compounds under anaerobic condition Biogas is mainly composed of methane CH4 and carbon dioxide CO2 Anaerobic digestion involves the degradation and stabilization of organic materials under anaerobic conditions by microbial organisms and leads to the formation of biogas and microbial biomass Anaerobic treatment provides a method of reducing pollution from agricultural and industrial operations while at the same time offsetting the operations usage of fossil fuels In this research baker s yeast wastewater which had high amounts of COD 10 000 mg lit was used for biogas production Overliming adding Ca OH 2 has been recognized as the most common treatment because of its low costs and high efficiency among the detoxification methods Thus overliming was used for the detoxification of inhibitors such as ammonia and phenolic compounds present in the wastewater Ammonia and phenolic compounds are considered to be important inhibitors due to their inhibitory effect in anaerobic digestion microorganism These inhibitors make transient complexes with calcium ions and sediment The effects of different conditions of overliming temperature pH and time on biogas production were studied Overliming was carried out in a factorial designed experiment by increasing the pH to 9 10 11 and 12 at two different temperatures 20 C and 60 C holding the pH and temperature at constant values for different periods of time 0 2 and 12 hours All the detoxified baker s yeast wastewater was then anaerobicaly digested in batch cultivation in 118 ml bottles The conditions of T 20 C pH 11 and t 0 hr resulted in the maximum biogas production equal to 425 ml CH4 g COD Also the amount of biogas produced from the overliming conditions of T 20 C pH 10 and t 2 hr was 410 37 ml CH4 g COD which had the second best biogas production The maximum absolute yields of methane production were 3 06 lit CH4 lit wastewater and 2 71 lit CH4 lit wastewater for the overliming conditions of T 20 C pH 10 t 2 hr and T 20 C pH 11 t 0 hr respectively At these optimum conditions the amount of inhibitors is lower than their minimum toxic concentration and also the percent of eliminated COD is minimum too maximizing the biogas yield In this research alongside producing biogas as a renewable source of energy and also the reduction in the COD the concentration of heavy metals such as cadmium Cd lead Pb and Zinc Zn were reduced during the anaerobic digestion process Results show that overliming is an effective method for the detoxification of baker s yeast wastewater and increasing biogas yield Keywords Biogas Anaerobic digestion Baker s yeast waste Inhibitors Overliming

سيدي نياسر، حجت

افزايش راندمان توليد بيوگاز در راكتور ناپيوسته با استفاده از تخمير پساب صنايع

هضم بي هوازي , پساب خمير مايه , تركيبات بازدارنده , آهك زني