A laboratory scale up-flow biological activated carbon(BAC) reactor was constructed for the advanced treatment of synthetic flotation wastewater. Biodegradation of a common collector(i.e., ethyl xanthate) for non-ferr...A laboratory scale up-flow biological activated carbon(BAC) reactor was constructed for the advanced treatment of synthetic flotation wastewater. Biodegradation of a common collector(i.e., ethyl xanthate) for non-ferrous metallic ore flotation was evaluated. The results show that the two stages of domestication can improve microbial degradation ability. The BAC reactor obtains a chemical oxygen demand(COD) reduction rate of 82.5% for ethyl xanthate and its effluent COD concentration lowers to below 20 mg/L. The kinetics equation of the BAC reactor proves that the activated carbon layers at the height of 0 mm to 70 mm play a key role in the removal of flotation reagents. Ultraviolet spectral analysis indicates that most of the ethyl xanthate are degraded by microorganisms after advanced treatment by the BAC reactor.展开更多
选择闽江河口典型芦苇(Phragmites australis)湿地为研究对象,基于野外氮负荷增强模拟试验(NN,无氮负荷处理,0 g N m^(-2)a^(-1);NL,低氮负荷处理,12.5 g N m^(-2)a^(-1);NM,中氮负荷处理,25.0 g N m^(-2)a^(-1);NH,高氮负荷处理,75.0 g...选择闽江河口典型芦苇(Phragmites australis)湿地为研究对象,基于野外氮负荷增强模拟试验(NN,无氮负荷处理,0 g N m^(-2)a^(-1);NL,低氮负荷处理,12.5 g N m^(-2)a^(-1);NM,中氮负荷处理,25.0 g N m^(-2)a^(-1);NH,高氮负荷处理,75.0 g N m^(-2)a^(-1)),通过获取不同年份冬季各氮负荷样地土壤开展室内培养实验,对比研究了氮负荷持续9个月(2021年12月,WT9)和21个月(2022年12月,WT21)后湿地土壤的N_(2)O产生过程。结果表明,氮负荷增强条件下湿地土壤不同过程的N_(2)O产生量发生了明显改变,不同年份土壤的N_(2)O总产生量均在NM处理下最高。异养反硝化作用对不同年份土壤的N_(2)O产生均存在较大的削弱作用,但其N_(2)O产生量整体随氮负荷时间的延长而增加;不同氮负荷处理下的非生物作用均是N_(2)O产生的重要过程,但其N_(2)O产生量在较短时期(WT9)随氮负荷水平的升高呈降低变化,而在较长时期(WT21)则呈增加趋势。不同氮负荷处理下非生物过程对N_(2)O产生的较大贡献主要与该区土壤铁锰、硫化物等含量丰富以及氮负荷增强条件下土壤酸碱状况(pH)的改变有关。氮负荷水平与温度对不同年份冬季土壤的N_(2)O产生过程均存在不同程度的交互影响,不同处理下的N_(2)O产生在WT9时期的较低温度下(5.5—11.5℃)以非生物作用为主,在WT21时期以硝化作用和非生物作用为主;而在较高温度下(17.5℃),不同年份冬季土壤的N_(2)O产生均以非生物作用和硝化细菌反硝化作用为主。研究发现,氮负荷增强改变了不同年份冬季土壤N_(2)O产生的生物和非生物贡献模式,其主要通过改变土壤养分状况来影响N_(2)O产生的生物或非生物过程。在闽江河口湿地冬季低温并叠加氮负荷增强条件下,其对土壤N_(2)O产生的综合影响表现为抵消效应,而这有助于降低该区冬季的N_(2)O排放量。展开更多
基金Project(201209013)supported by Special Fund for Environmental Scientific Research in the Public Interest,China
文摘A laboratory scale up-flow biological activated carbon(BAC) reactor was constructed for the advanced treatment of synthetic flotation wastewater. Biodegradation of a common collector(i.e., ethyl xanthate) for non-ferrous metallic ore flotation was evaluated. The results show that the two stages of domestication can improve microbial degradation ability. The BAC reactor obtains a chemical oxygen demand(COD) reduction rate of 82.5% for ethyl xanthate and its effluent COD concentration lowers to below 20 mg/L. The kinetics equation of the BAC reactor proves that the activated carbon layers at the height of 0 mm to 70 mm play a key role in the removal of flotation reagents. Ultraviolet spectral analysis indicates that most of the ethyl xanthate are degraded by microorganisms after advanced treatment by the BAC reactor.
文摘选择闽江河口典型芦苇(Phragmites australis)湿地为研究对象,基于野外氮负荷增强模拟试验(NN,无氮负荷处理,0 g N m^(-2)a^(-1);NL,低氮负荷处理,12.5 g N m^(-2)a^(-1);NM,中氮负荷处理,25.0 g N m^(-2)a^(-1);NH,高氮负荷处理,75.0 g N m^(-2)a^(-1)),通过获取不同年份冬季各氮负荷样地土壤开展室内培养实验,对比研究了氮负荷持续9个月(2021年12月,WT9)和21个月(2022年12月,WT21)后湿地土壤的N_(2)O产生过程。结果表明,氮负荷增强条件下湿地土壤不同过程的N_(2)O产生量发生了明显改变,不同年份土壤的N_(2)O总产生量均在NM处理下最高。异养反硝化作用对不同年份土壤的N_(2)O产生均存在较大的削弱作用,但其N_(2)O产生量整体随氮负荷时间的延长而增加;不同氮负荷处理下的非生物作用均是N_(2)O产生的重要过程,但其N_(2)O产生量在较短时期(WT9)随氮负荷水平的升高呈降低变化,而在较长时期(WT21)则呈增加趋势。不同氮负荷处理下非生物过程对N_(2)O产生的较大贡献主要与该区土壤铁锰、硫化物等含量丰富以及氮负荷增强条件下土壤酸碱状况(pH)的改变有关。氮负荷水平与温度对不同年份冬季土壤的N_(2)O产生过程均存在不同程度的交互影响,不同处理下的N_(2)O产生在WT9时期的较低温度下(5.5—11.5℃)以非生物作用为主,在WT21时期以硝化作用和非生物作用为主;而在较高温度下(17.5℃),不同年份冬季土壤的N_(2)O产生均以非生物作用和硝化细菌反硝化作用为主。研究发现,氮负荷增强改变了不同年份冬季土壤N_(2)O产生的生物和非生物贡献模式,其主要通过改变土壤养分状况来影响N_(2)O产生的生物或非生物过程。在闽江河口湿地冬季低温并叠加氮负荷增强条件下,其对土壤N_(2)O产生的综合影响表现为抵消效应,而这有助于降低该区冬季的N_(2)O排放量。
