CAJ | 학술논문

采用生物修复方法,通过实验室模拟试验,比较水稻秸秆、玉米芯和报纸3种不同固体碳源在不同温度和水力停留时间(hydraulic retention time,HRT)条件下对地下水硝酸盐的去除效果,以便筛选出优质固体碳源为污染场地应用提供参考.结果表明,以水稻秸秆和玉米芯作为碳源,硝酸盐的去除效果最佳.在初始硝酸盐质量浓度为30 mg/L(以 N 计)条件下,硝酸盐去除率均在24 h 内达到100%,并且产生的亚硝酸盐质量浓度较低,亚硝酸盐有短暂升高现象但24 h 之后降至0.1 mg/L 以下,因此水稻秸秆和玉米芯可作为较优质的固体碳源.在4个不同温度条件下(15,20,25,30℃),添加3种碳源的反硝化效果均表现为温度越高硝酸盐去除率越高,同时去除率达到100%所用时间越短,产生的亚硝酸盐质量浓度越低,而且温度在25~30℃时反硝化效果达到最优.筛选出的2种较优碳源水稻秸秆和玉米芯,在不同 HRT 条件下(6.7,10,20,40 h)均表现为 HRT 越长,硝酸盐质量浓度有显著降低,亚硝酸盐质量浓度峰值越低且降低的也越快.以玉米芯为碳源时,在不同 HRT 条件下,铵态氮质量浓度均随时间逐渐降低,在30 h 之内降至5 mg/L 以下；以秸秆为碳源时,铵态氮质量浓度则呈现先升高后降低趋势并且呈现 HRT 越长铵态氮质量浓度累积越高,整体呈现铵态氮质量浓度高于玉米芯.以玉米芯为碳源时,pH 略低,在5~6范围内波动；以秸秆为碳源时 pH 值波动范围为6.5~7.5,更适宜微生物生长.结果证明,秸秆和玉米芯为较优质碳源,但各有不足之处,在实际应用中应结合场地水流速度、pH 等条件选择相对更优碳源,也可将二者混合使用使优势互补.
채용생물수복방법,통과실험실모의시험,비교수도갈간、옥미심화보지3충불동고체탄원재불동온도화수력정류시간(hydraulic retention time,HRT)조건하대지하수초산염적거제효과,이편사선출우질고체탄원위오염장지응용제공삼고.결과표명,이수도갈간화옥미심작위탄원,초산염적거제효과최가.재초시초산염질량농도위30 mg/L(이 N 계)조건하,초산염거제솔균재24 h 내체도100%,병차산생적아초산염질량농도교저,아초산염유단잠승고현상단24 h 지후강지0.1 mg/L 이하,인차수도갈간화옥미심가작위교우질적고체탄원.재4개불동온도조건하(15,20,25,30℃),첨가3충탄원적반초화효과균표현위온도월고초산염거제솔월고,동시거제솔체도100%소용시간월단,산생적아초산염질량농도월저,이차온도재25~30℃시반초화효과체도최우.사선출적2충교우탄원수도갈간화옥미심,재불동 HRT 조건하(6.7,10,20,40 h)균표현위 HRT 월장,초산염질량농도유현저강저,아초산염질량농도봉치월저차강저적야월쾌.이옥미심위탄원시,재불동 HRT 조건하,안태담질량농도균수시간축점강저,재30 h 지내강지5 mg/L 이하；이갈간위탄원시,안태담질량농도칙정현선승고후강저추세병차정현 HRT 월장안태담질량농도루적월고,정체정현안태담질량농도고우옥미심.이옥미심위탄원시,pH 략저,재5~6범위내파동；이갈간위탄원시 pH 치파동범위위6.5~7.5,경괄의미생물생장.결과증명,갈간화옥미심위교우질탄원,단각유불족지처,재실제응용중응결합장지수류속도、pH 등조건선택상대경우탄원,야가장이자혼합사용사우세호보.
Summary Groundwater is not only an important component of the hydrologic cycle but also an important drinking water source.Excessive nitrogen fertilizer and organic manure application has caused severe nitrate pollution in groundwater,which threats human health.Bioremediation of groundwater nitrate using denitrifying forms of bacteria found in groundwater is one of the effective methods for nitrogen removal. <br> Carbon source is one of the necessities for heterotrophic denitrification,and water temperature and hydraulic retention time can also significantly influence the nitrate removal efficiency.The main objectives of this study are to:1) investigate the performance of denitrification using different single carbon sources;2) evaluate the effects of temperature,hydraulic retention time (HRT) and pH on denitrification performance and screen the best solid carbon source for nitrate removal. <br> This research focused on nitrate removal using commonly available agricultural solid organic residues as the carbon sources.Particularly,corncob,rice straw,and newspaper were employed as the carbon sources for nitrate removal at different temperatures and hydraulic retention times (HRT) in the laboratory. <br> The results indicated that when newspaper was used as carbon source,nitrate concentration was reduced from 30 to around 1 5 mg/L in 24 hours,and the nitrite concentration was much higher than the standard of the drinking water quality.On the other hand,use of corncob and rice straw as carbon sources could almost completely remove the nitrate within 24 hours.It was observed that small amount of nitrite was accumulated in the denitrification process when corncob and rice straw were used as the carbon sources.Denitrification was markedly affected by temperature.When rice straw and corncob were used as carbon sources,almost 100% nitrate removal was achieved within 60 hours at 20,25 or 30 ℃,while only 50% nitrate removal could be achieved at 1 5 ℃.Nitrite concentration increased at first,then decreased to below 0.1 mg/L within 24,40 and 24 hours,respectively,at 20,25 and 30 ℃when corncob or rice straw was used as carbon source.High nitrate removal efficiency could be achieved at the four different treatments of HRT by using corncob or rice straw as carbon source.But the time required for the near-complete removal of nitrate(stable operation) increased with the decrease of HRT. <br> This study indicated that complete nitrate removal can be achieved readily using rice straw or corncob as carbon source by adjusting HRT or temperature in water, which can be potentially implemented in environmental engineering practices.