Study On Biological Desulfurization And Product Gas Of Molasses Alcohol Wastewater

As the high-concentration organic wastewater discharged from the alcohol production process in the sugar industry,molasses alcohol waste liquid can be used for biogas production by anaerobic biological treatment to achieve resource utilization.However,the high sulfate content greatly restricts the waste liquid anaerobic biological treatment process.In this paper,the conditions of Fenton process,modified bagasse ash pretreatment of high concentrations of sulfate and pigment material in molasses alcohol wastewater and the removal of sulfate ions by modified bagasse ash sulfate were optimized,and the Fe²⁺anaerobic and micro-oxygen anaerobic treatment of molasses alcohol wastewater and microbial community structure comparison.The main conclusions are as follows:When molasses alcohol waste is diluted 100 times,the best conditions for pretreatment with Fenton are:pH 2.5 for each 50 mL of molasses alcohol waste,2.0mL of H₂O₂,1.8 mL of Fe²⁺,reaction time of 90 min,and reaction temperature of30°C.The color and COD_Cr removal rates reached 92.31%and 78.55%,respectively.The modified bagasse ash was treated with the Fenton-treated wastewater.The optimized conditions were:modified bagasse incineration ash dosage 3 g/50 mL,reaction time 60 min,reaction temperature 45°C,pH 1.88（pH after Fenton）,At this time,the removal rates of color,COD_Cr,and SO₄^2-were 47.46%,14.68%,and 73.51%,respectively.The optimum conditions for removing the chroma,COD_Cr and SO₄^2-in the waste liquid of molasses pretreated by Fenton using the modified bagasse ash immobilized sulfate reducing bacteria were as follows:the reaction temperature was 40°C,the pH was 7 and the immobilizing agent was added.The amount was 20 g,and the chroma,COD_Cr,and SO₄^2-removal rates in the molasses alcohol waste solution reached49.19%,81.72%,and 70.75%,respectively.Two kinds of anaerobic treatment methods were used to increase the anaerobic treatment effect of molasses alcohol waste liquid by adding Fe²⁺and microaerobic two kinds of anaerobic treatment of molasses alcohol waste liquor.The anaerobic reaction of adding Fe²⁺was performed.The colorimetric,COD_Cr and SO₄^2-removal rates in molasses alcohol waste reached 27.42%,62.37%and 87.53%,respectively;the microanaerobic anaerobic reaction removed the chroma,COD_Cr and SO₄^2-in the molasses alcohol waste liquor,respectively It is 29.84%,64.95%,and 80.22%.Gas production rate:The maximum anaerobic process is 250L/（kgCOD）,the anaerobic addition of Fe²⁺dosing is about 110 L/（kgCOD）,and the microaerobic anaerobic is about 90 L/（kgCOD）.Comparing Fe²⁺and microaerobic two kinds of anaerobic treatment of molasses alcohol waste liquid,the results showed that adding Fe²⁺and microaerobic two anaerobic treatment methods can improve the anaerobic treatment effect of molasses alcohol waste liquid.The highest chroma,COD_Cr and SO₄^2-removal rates in the molasses alcohol waste liquid were 27.42%,62.37%and 87.53%,respectively when Fe²⁺was added.The removal rates of color,COD_Cr and SO₄^2-in molasses alcohol waste liquor under microaerobic conditions were 29.84%,64.95%and 80.22%.The rate of gas production in the control group was 250 L/（kg COD）,the rate of gas production with Fe²⁺fluctated around 110 L/（kg COD）,and the rate of gas production with micro oxygen fluctuate around 90 L/（kg COD）.Through the analysis of the biological diversity of different anaerobic processes,it was found that both Desulfovibrio and Thiobacillus in anaerobic reactors play an important role in the removal of SO₄^2-in molasses alcoholic wastewater.Methanolinea,Methanospirillum,Methanobrevibacter and Methanosphaera are of great significance for anaerobic methane production.