Electricity Generation from Sugar Processing Waste water Using Environmental Friendly Dual Chamber Microbial Fuel Cell

Energy crises in Pakistan are evaluated in terms of inclination since last few years and these crises mainly dependable on the depletion of petroleum. The focus of world is diverting towards the sustainable renewable energy sources. Microbial fuel cell is one of the emerging technologies that use the concept of clean energy using environmental friendly process with the utilization of microbes. In this research a microbial activity is observed that generates electricity from sugar processing wastewater using a dual chamber microbiological reactor. Different observations has been carried out to analyze the wastewater and microbiological parameters with respect to time and it was analyzed that fuel cell generates electricity of 1.28 mA, 0.9 volts and 0.304 Watt/m2. Along with the energy generation, the waste water is also treated with this microbial cell having effectiveness of TDS 56.35%, COD 69.3% and BOD 68.1% removal. Due to this efficiency, the microbial fuel cell may replace the conventional harmful energy sources.


Introduction
The modern era is diverting towards the mechanization and metropolitanization specially the third world country like Pakistan. This industrial revolution causes the environmental issues and energy crises. The main reason for these crises is the reliance on the fossil fuels and untreated effluent disposal. Various organic wastes causes the problems like leachate that affects the constituents of biosphere [1][2][3] . The high valued organic wastes are most abundant in the effluents of industrial waste streams [4,5] . Sugar industry generates unwanted residual liquid waste during the production and processing of products. The waste water from sugar industry generated in the ratio of 1000 liters/ton of sugarcane [6][7][8] . Effluent water of sugar industry contains the high organic content that microbes utilize along with dissolve oxygen of water causes it inappropriate for the Biopsheric [9] . This contamination in the biosphere results as a habitat hazard [10] . Cleanup treatments like bioremediation of sugar industry's wastewater are being under consideration [11] . The emerging bioremediation technology with the sustainable electricity generation is known as microbial fuel cell [12] . The fuel cell utilizing the microbes generates electrical energy by the organic waste using the microbial catalytic activity for free electrons generation by conversion of chemical energy of waste along with the sustainable treatment of wastewater [13] . The sustainable development of fuel cell technology using microbe scope towards the solution of energy crises by generating electricity and hydrogen along with the effluent treatment of organic wastes [14] . Treatment applications using MFCs applicable for domestic sewage, brewery, distillery, sugar, paper and pulp, rice mill, swine wastewater and phenolic wastewater [15] . Furthermore supremacy of MFCs is prospective of bio solid production in collation of Aerobic treatments.

Wastewater collection
Wastewater was assembled from molasses creation plant, Malegaon Sugar Factory, in Maharashtra, India. The wastewater was used as substrate for all tests without additions of any other nutrient or trace metal. Wastewater effluent was refrigerated at about 4 0 C prior to processing.

Fabrication of Microbial Fuel Cell (MFC)
Duel Chamber Microbial fuel cell have been fabricated for the treatment of sugar and mill wastewater.

Construction of Microbial Fuel Cell
Stride 1: Anodic compartment selection: Anodic chamber was selected as a plastic compartment with non-reactive nature.

Stride 2: Protonic permeable salt bridge path preparation:
The Agar salt bridge was constructed using common salt, agar and water. 650 ml of water was boiled in a beaker, 65 grams of agar and 75 grams of salt were added to the boiling water, the mixture was further boiled for 3 -5 minutes. The mixture is placed in PVC pipe and allowed to solidify and was kept in the refrigerator for 24 hours.

Stride 3: Electrodes foregathering:
Electrodic material was selected as graphite for both cathodic and anodic electrode. Ordering of electrodes was done in such a way it seems as a brush of graphite on plastic pipe as shown in Figure 1. The dimensions of graphitic rods are such as its length is 90 mm and diameter is 2 mm. Microbial fuel cell doesn't contain a separate cathodic chamber but instead of it the rods of graphitic pencils were arranged on the protonic permeable salt bridge with the wounded copper wire that behaves like a cathode for the cell. Electronic acceptance from anodic chamber was boosted from the oxygenated air. Anodic chamber was all with Ditch on the top so that graphitic rods with plastic pipe and copper rounds can go through the ditch.

Results and Discussion
General The characteristics of sugar wastewater and the experimental data relating to single chambered microbial fuel are discussed here.
Quality parameters of sugar wastewater: The qualitative parameters of sugar wastewater are presented in (Table 1). Treatment and current generation using various concentrations of sugar wastewater: Feed concentration of wastewater was prepared by diluting it with water. Variation in the attentiveness of microbiological fuel cell's substrate was regarded as feed concentration. The influent(I), effluent(E) and percent removal (%) of chemical oxygen demand, Total dissolved solids and Biochemical oxygen demand for various feed concentrations are presented in tables. From the above data, it is seen as microbiological fuel cell containing sugar wastewater has ability to reduction of COD that pointed out that organic in waste were metabolized by the microorganism act as electronic donor. Total suspended solids along with the chemical and biochemical oxygen demand were analyzed linearly in MFC. The effectiveness of MFC analyzed day by day removal efficiency that BOD ranges as 34.6% to 68.1%, COD ranges as 35% to 69.3%, TDS ranges as 25.4% to 56.3%, pH ranges as 7.1% to 8.2%, current ranges as 0.11 to 1.28 mA, voltage ranges as 0.1 to 0.9 V and increment in the feed concentration is 200 mg COD/l to 1400 mg COD/l.

Effective analysis of feed concentration and time with respect to COD removal:
The microbes in the fuel cell actively seen as working like metabolization agent for organic source and this behavior indicates the effectiveness of Chemical oxygen demand removal. Experimental values showed significant potential of COD removal along with current generation with respect to residence time in fuel cell. The feed concentration seems to increase from 200 mg COD/l to 1400 mg COD/l with the removal efficiency of COD from 35 % to 69.3% as shown in (Figure 2). With the feed concentration increment, efficiency of COD removal tends to increase linearly. The equilibrium maintained in 3 to 4 days of feed concentration and COD removal with the time gradient.

Analysis of pH variation of Sugar wastewater at different residence time in MFC:
In dual chamber microbiological cell, the pH tends to increases with respect to residence time. This pH is also dependent on the feed concentration. As feed concentration increases from 200 mg COD/l to 1400 mg COD/l with respect to time from 0 to 44 days, the pH also tends to increases from 6.9 to 8.4. The equilibrium maintained in 3 to 4 days of feed concentration and pH increment with the time gradient.