EFFECT OF DIFFERENT MICROBIAL CULTURE ON BIOHYDROGEN PRODUCTION FROM BENINCASA HISPIDA WASTE Minu Singh, Dolly Kumari, Pooja Chahar, Yogita Singhal and Radhika Singh* Biohydrogen Production Lab, Deptt of Chemistry, Faculty of Science, Dayalbagh Educational Institute, Agra-282005 Email id: bioenergy.dei2011@gmail.com and *radhika1263@gmail.com Abstract— Biohydrogen production has gained attention in recent years using anaerobic degradation method. In the present study, Benincasa hispida (petha) solid waste generated from industries were used as substrate. Three different inoculum namely, cow dung (CD), goat dung (GD) and pretreated soil (SP) were used as a bacterial source. They were used separately and also in combination of two cultures in equal ratio. The cultures then mixed with petha waste slurry in 20:80 in batch reactor of 500 mL with a working volume of 400 mL under anaerobic conditions. Substrate used in the present study had chemical oxygen demand and glucose concentration of 3150 mg/L and 11 mg/L respectively. Biohydrogen was found to be maximum in GD+CD (87%) used as the bacterial inoculum. Acetic acid was also estimated and a maximum concentration of 2650 ppm was found in the reactor operated using GD as bacterial source. Degradation in various parameters was also studied in terms of COD, glucose. Keywords— Goat dung, biohydrogen, acetic acid, petha waste I. INTRODUCTION With increasing volume of waste worldwide, the environmental challenges related to waste management are growing apart. Also, with the growing demerits of fossil fuels - its finitude and negative impact on the environment and public health - renewable energy is becoming a favored emerging alternative. Recently almost all of the energy requirements are dependent on fossil energy sources that are not renewable and affect the environment because of the production of huge amount of greenhouse gases and pollutants (Guo et.al, 2010). Hence, one of the biggest challenges in the present decade is the discovery of ecofriendly renewable energy sources. Biological processes are considered as the most eco-friendly alternatives for satisfying future energy demands. Due to high moisture and organic content in fruits and vegetable wastes, they can be utilized in biological treatment like anaerobic digestion than other techniques like incineration and composting. Bioconversion processes are preferred for waste treatment then the thermo-conversion processes due to the presence of high moisture content. Vegetable wastes, due to high biodegradability and high moisture content (75 – 90%) are good substrate for bio-energy recovery through anaerobic digestion process (Viturtia A et.al, 1989). Anaerobic digestion is the biological degradation by a complex microbial ecosystem of organic and occasionally inorganic substrates in the absence of an organic source. Hydrogen is considered as one of the most promising candidate as a substitute for conventional energy resources (Cao and Zhao, 2009 and Vadez et al 2005). Further, it should also be safe to use, and be potentially harmless to the environment. Although hydrogen does not exist freely in nature, it can be produced by various methods and of sources such as steam reformation of natural gas, gasification of coal, and electrolysis of water and bio hydrogen. Studies have shown that anaerobic digestion holds good and is a cost effective method. Singhal and Singh (2014a) carried out the treatment of B. hispida waste using microwave pretreated bacterial mixed culture 14mmol of hydrogen per mol of glucose was produced. In another study, Jamil.Z et.al. (2013) studied the optimum conditions for anaerobic co-digestion of food waste and sewage sludge and hydrogen production. The selected parameters for optimization of hydrogen production (e.g. temperature, initial pH, inoculum size) were analysed. Experiments at optimal parameter values yielded cumulative hydrogen of 0.28 ml H 2 /ml substrate for food waste. For the present study, Benincasa hispida was used as the substrate, which was discarded after making petha sweet, a delicacy of Agra, India. The process of manufacturing Petha sweet is completely manual. Consequently, during the production and manufacturing of the sweet there are three kinds of waste viz peels, pulp and seeds. All these are discarded without any utilization resulting in environmental pollution. Environmental degradation caused by this waste has been a cause of worry to the State Government (Singhal and Singh, 2014b). This waste is left out and discarded as such on the streets and creates aesthetic nuisance to the society and also increases the mosquitoes and flies causing various diseases. Hence, due to these reasons this substrate has been selected for the study, which was treated using three different types of mixed culture bacteria. The present study was focused on biodegradation of this petha waste with three different microbial culture and to establish the optimum bacterial source for the same. II. MATERIALS AND METHODS A. Inoculum Three different types of inoculum were used in this study and effect of inoculum was studied on the yield of biohydrogen production. Cow dung used as the inoculum in the study was