There are a lot of organic carbon sources in food waste, which shows a good property of resource utilization. By enzymatic hydrolysis, the carbon source suitable for wastewater treatment was recycled and prepared from food-waste solid residue. To acquire the optimal enzymatic conditions, the influence of enzymatic conditions on carbon source extraction and the interaction between key factors were investigated. Subsequently, isoelectric precipitation method was used to further improve the purity of recovered carbon source solution. The results demonstrated that the co-treatment of α-amylase and γ-amylase improved the extraction of carbon source and could reduce the enzyme amount used. Enzymatic temperature, pH and substrate mass concentration were the key factors affecting the synergistic effect of the two amylases. The order of influences on the extraction efficiency of carbon source was substrate mass concentration > temperature > pH, and there was a significant interaction effect between substrate mass concentration and temperature. The optimal conditions for carbon source extraction were 57.0 ℃, pH 6.2, substrate mass concentration 190 g/L, enzyme mass fraction added 0.6%, enzyme mass ratio 3∶1 (α∶γ), where the extraction efficiency of carbon source reached 76.9%. By isoelectric precipitation, the finally biochemical oxygen demand (BOD) concentration and BOD/N ratio in the recovered solution of carbon source reached 76.8 g/L and 51.2, respectively. The recovered solution can be used as a promising carbon source for wastewater treatment.
[1] REN Y Y, YU M, WU C F, et al.A comprehensive review on food waste anaerobic digestion:Research updates and tendencies[J].Bioresource Technology, 2018, 247(1):1 069-1 076.
[2] 赵明星, 黄月, 缪恒锋, 等.餐厨垃圾与剩余污泥协同厌氧连续处置研究[J].食品与发酵工业, 2020, 46(19):92-98.
ZHAO M X, HUANG Y, MIAO H F, et al.Continuous anaerobic co-digestion of food waste and excess sludge[J].Food and Fermentation Industries, 2020, 46(19):92-98.
[3] 邴君妍, 罗恩华, 金宜英, 等.中国餐厨垃圾资源化利用系统建设现状研究[J].环境科学与管理, 2018, 43(4):39-43.
BING J Y, LUO E H, JIN Y Y, et al.Current situation of food waste recycling in China[J].Environmental Science and Management, 2018, 43(4):39-43.
[4] LEE S, MOON T,PARK S, et al.Evaluation of industrial organic waste as an alternative external carbon source for denitrification in the biological nutrient removal process[J].Korean Journal of Chemical Engineering, 2013, 30:1 911-1 917.
[5] SHANG H M, CHEN S L, LI R, et al.Influences of extraction methods on physicochemical characteristics and activities of Astragalus cicer L.polysaccharides[J].Process Biochemistry, 2018, 73:220-227.
[6] WU H Y, SHANG H M, GUO Y, et al.Comparison of different extraction methods of polysaccharides from cup plant (Silphium perfoliatum L.)[J].Process Biochemistry, 2020, 90:241-248.
[7] CASTOLDI R, CORREA V G, DE MORAIS G R, et al.Liquid nitrogen pretreatment of eucalyptus sawdust and rice hull for enhanced enzymatic saccharification[J].Bioresource Technology, 2017, 224:648-655.
[8] YIN Y, LIU Y J, MENG S J, et al.Enzymatic pretreatment of activated sludge, food waste and their mixture for enhanced bioenergy recovery and waste volume reduction via anaerobic digestion[J].Applied Energy, 2016, 179:1 131-1 137.
[9] INDRIATI G, MEGAHATI R R P, ROSBA E.Potency of amylase-producing bacteria and optimization amylase activities[J].Materials Science and Engineering, 2018, 335(1):012 023.
[10] GIDLEY M J, COOKE D, DARKE A H, et al.Molecular order and structure in enzyme-resistant retrograded starch[J].Carbohydrate Polymers, 1995, 28(1):23-31.
[11] ZHU X T, TIAN Y Q, XU W, et al.Bioconversion of sucrose to maltooligosaccharides by the synergistic action of amylosucrase and α-amylase[J].Process Biochemistry, 2018.74:71-76.
[12] 沈唯军, 时晨, 丁婷.应用固定化α-淀粉酶探究温度对酶活性的影响[J].生物学教学, 2018, 43(3):44-45.
SHEN W J, SHI C, DING T.Application of immobilized α-amylase to explore the effect of temperature on enzyme activity[J].Biology Teaching, 2018, 43(3):44-45.
[13] 武崇辉, 武瑞娟, 刘懿霆, 等.酸碱预处理后玉米秸秆的酶解工艺优化[J].太阳能学报, 2016, 37(6):1 528-1 533.
WU C H, WU R J, LIU Y T, et al.Enzymatic hydrolysis optimazation of corn straw in acid and alkali pretreatment[J].Acta Energiae Solaris Sinica, 2016, 37(6):1 528-1 533.
[14] 尚谦, 王英辉, 张瑞杰, 等.酶法降解木薯渣效果的实验研究[J].环境科学与技术, 2017, 40(1):31-36.
SHANG Q, WANG Y H, ZHANG R J, et al.Study on effects of degradation of cassava dregs by adding enzymes[J].Environmental Science and Technology, 2017, 40(1):31-36.
[15] KARI J, SCHIANO-DÍ-COLA C,HANSEN S F, et al.A steady-state approach for inhibition of heterogeneous enzyme reactions[J].The Biochemical Journal, 2020, 477(10):1 971-1 982.
[16] 王永菲, 王成国.响应面法的理论与应用[J].中央民族大学学报(自然科学版)2005, 14(3):236-240.
WANG Y F, WANG C G.The application of response surface methodology[J].Journal of the Central University for Nationalities(Natural Science Edition), 2005, 14(3):236-240.
[17] 廖灿杰, 杨宏, 王玉栋, 等.响应面法优化番木瓜籽蛋白质提取工艺[J].食品研究与开发, 2020, 41(1):147-154.
LIAO C J, YANG H, WANG Y D, et al.Optimization on aqueous enzymatic extraction process of protein from the seeds of Carica papaya L.by response surface methodology[J].Food Research and Development, 2020, 41(1):147-154.
[18] 施正华, 李秀芬, 宋小莉, 等.采用等电点沉淀法回收市政污泥水解液中的蛋白质[J].环境工程学报, 2016, 10(10):5 919-5 923.
SHI Z H, LI X F, SONG X L, et al.Protein recovery from hydrolysis solution of municipal sludge by isoelectric point precipitation[J].Chinese Journal of Environmental Engineering, 2016, 10(10):5 919-5 923.
[19] 熊子康, 郑怀礼, 尚娟芳, 等.污水反硝化脱氮工艺中外加碳源研究进展[J].土木与环境工程学报, 2021, 43(2):168-181.
XIONG Z K, ZHENG H L, SHANG J F, et al.State-of-the art review of adding extra carbon sources to denitrification of wastewater treatment[J].Journal of Civil and Environmental Engineering, 2021, 43(2):168-181.
[20] 景香顺, 李鑫玮, 张晓红, 等.低碳源市政污水处理优化运行的研究与工程应用[J].给水排水, 2019, 55(11):33-37.
JING X S, LI X W, ZHANG X H, et al.Research and engineering application of optimized operation of municipal wastewater treatment with low carbon source[J].Water and Wastewater Engineering, 2019, 55(11):33-37.
