奶牛场高浓度污水絮凝处理中试效果研究  

A pilot study of pre-treating high-strength wastewater from a dairy farm by flocculation

作　　者：宋建超 尚斌[1] 温富勇 陶秀萍[1] 陈永杏[1] 赵海明 SONG Jianchao;SHANG Bin;WEN Fuyong;TAO Xiuping;CHEN Yongxing;ZHAO Haiming(Key Laboratory of Energy Conservation and Waste Management in Agricultural Structures,Ministry of Agriculture/Institute of Environment&Sustainable Development in Agriculture,Chinese Academy of Agricultural Sciences,Beijing 100081,China;Miyun District Agriculture Bureau of Beijing City,Beijing 101500,China)

机构地区：[1]中国农业科学院农业环境与可持续发展研究所/农业农村部设施农业节能与废弃物处理重点实验室,北京100081 [2]北京市密云区农业局,北京101500

出　　处：《畜牧与兽医》2021年第4期48-53,共6页Animal Husbandry & Veterinary Medicine

基　　金：北京市奶牛产业创新团队项目(BAIC06-2020);中国农业科学院科技创新工程协同创新任务(CAAS-XTCX2016011-01)。

摘　　要：奶牛场的粪尿混合物经固液分离后的污水含有机物浓度高,无法直接采用生物法一步处理,为此开展了化学絮凝预处理中试研究,旨在为开发经济高效且工艺简单的奶牛场污水深度处理工艺提供依据。试验在前期小试的基础上,中试采用试制容积1 m3絮凝中试装置,对3种无机絮凝剂聚合氯化铝(polymeric aluminum chloride,PAC)、聚合硫酸铁(polymeric ferric sulfate,PFS)和聚合氯化铝铁(polyaluminum ferric chloride,PAFC),3种搅拌速度100 r/min、200 r/min和300 r/min,3种搅拌时间6 min、10 min和14 min,采用正交试验设计形成9个处理进行絮凝效果研究,同时对非离子聚丙烯酰胺(non-ionic polyacrylamide,NPAM)的4种投加比例的絮凝效果进行比较。当奶牛场污水化学需氧量(chemical oxygen demand,COD)、浊度和总悬浮固体浓度(total suspended solids,TSS)分别为7800~19480 mg/L、3360~10860 NTU和6090~21650 mg/L时,无机絮凝的最佳参数条件为:50 g/L PFS按体积比6∶100投加(浓度为3 g/L)、300 r/min快速搅拌30 s、200 r/min中速搅拌10 min。最佳参数的验证试验结果显示,对COD、浊度、TSS和总磷(total phosphorus,TP)的去除率分别为:69.8%±2.5%、86.0%±5.6%、86.1%±1.4%和76.3%±2.7%;非离子聚丙烯酰胺(1 g/L NPAM)的最佳体积投加比为0.25%(絮凝剂浓度2.5 mg/L),以300 r/min快速搅拌30 s后,再以200 r/min中速搅拌10 min,污水COD为(19975±1277)mg/L、浊度为(10648±3107)NTU、TSS为(17710±1021)mg/L和总磷为(255±69)mg/L时,去除率分别为68.0%±2.0%、79.8%±7.8%、79.7%±8.4%和85.3%±6.9%。综合絮凝效果和运行成本,按0.25%的比例投加1 g/L NPAM(即NPAM浓度2.5 mg/L)为奶牛场污水絮凝的最佳选择,其絮凝运行费用为0.08元/m^(3),研究结果可为奶牛场选择合适的絮凝前处理方法,以及经济实用的高浓度污水深度处理工艺的开发提供技术参考。Wastewater from dairy farms often contains a large amount of organic matters and suspended matters,and the contents are too high to be treated using a one-step biological strategy.A pilots study was carried out here to test the practicability of flocculation pretreatment of the wastewater with optimal operating parameters.An experimental apparatus with a capacity of 1 m3was designed and made.Three inorganic flocculants:polymeric aluminum chloride(PAC),polymeric ferric sulfate(PFS)and polyaluminum ferric chloride(PAFC),three moderate mixing speeds:100 r/min,200 r/min and 300 r/min,and three durations of moderate mixing:6 min,10 min and 14 min,were adopted.Nine treatments were formed using orthogonal experimental design,and the effects of four doses of non-ionic polyacrylamide(NPAM)were also compared.The results were as follows:When the influent concentrations of chemical oxygen demand(COD),turbidity and total suspended solids(TSS)were 7880-19480 mg/L,3620-10740 NTU and 5770-21650 mg/L,respectively,the operational parameters for inorganic flocculation were optimized as:50 g/L polymeric ferric sulfate(PFS)at a volumetric ratio of 6∶100(the flocculant concentration of 3 g/L),at a rapid stirring speed of 300 rpm for 30 s and then at moderate stirring speed of 200 rpm for 10 min.Under such operational conditions,the removal rates of COD,turbidity,TSS and total phosphorus were 69.8%±2.5%,86.0%±5.6%,86.1%±1.4%and 76.3%±2.7%,respectively.The optimal dosage for non-ionic polyacrylamide(NPAM)was 0.25%(v/v)at a pre-prepared concentration of 1 g/L(the flocculant concentration of 2.5 mg/L),accompanied with 300 r/min rapid stirring for 30 s plus 200 r/min moderate stirring for 10 min,when COD,turbidity,TSS and total phosphorus concentrations in the wastewater were(19975±1277)mg/L,(10648±3107)NTU,(17710±1021)mg/L and(255±69)mg/L,and the corresponding removal rates of NPAM were 68.0%±2.0%,79.8%±7.8%,79.7%±8.4% and 85.3%±6.9%,respectively.Based on both the above flocculation effects and the operating costs,organic fl

关 键 词：絮凝 污水 奶牛场 预处理 

分 类 号：X703.1[环境科学与工程—环境工程]