腐殖质胶结团聚体对苯酚的富集特征

为探讨不同腐殖质组分团聚体对苯酚富集能力的影响,应用国际腐殖酸协会（IHSS）推荐方法提取腐殖质,以Ca2+、Al3+、Fe3+为桥键离子,制备了高岭石、蒙脱石不同腐殖质组分团聚体,采用平衡吸附法研究了不同腐殖质组分团聚体对苯酚的富集特征.结果表明:高岭石不同腐殖质组分团聚体对苯酚的饱和吸附量（Q_m）大小依次为FA（富里酸）团聚体[（254.11±5.35）mg/kg] > HA（胡敏酸）团聚体[（186.14±1.61）mg/kg] > HM（胡敏素）团聚体[（120.61±1.67）mg/kg];蒙脱石不同腐殖质组分团聚体对苯酚的饱和吸附量大小依次为FA团聚体[（418.72±19.14）mg/kg）] > HA团聚体[（290.00±13.06）mg/kg）] > HM团聚体[（160.46±4.92）mg/kg）];高岭石不同腐殖质组分团聚体对苯酚的富集系数（ER）大小依次为FA团聚体（2.03±0.07）> HA团聚体（1.91±0.04）> HM团聚体（1.85±0.04）;蒙脱石不同腐殖质组分团聚体对苯酚的富集系数大小依次为FA团聚体（2.50±0.10）> HA团聚体（2.45±0.11）> HM团聚体（1.36±0.04）.研究显示,FA团聚体对苯酚的饱和吸附量和富集系数较大,对苯酚的吸附（富集）作用较强,HM团聚体对苯酚的饱和吸附量和富集系数较小,对苯酚的吸附（富集）作用较弱.不同腐殖质组分团聚体对苯酚的富集能力大小表现为FA团聚体> HA团聚体> HM团聚体.因此,FA团聚体可作为控制受苯酚污染场地土壤的首选修复剂.      

臭氧-生物活性炭对微污染原水中典型持久性有机物的去除效果

以长三角地区J市典型有机微污染水源P水厂为研究对象,考察了臭氧-生物活性炭深度处理工艺对微污染水源水中有机物的去除效果.结果表明,臭氧-生物活性炭深度处理使高锰酸盐指数、总有机碳(TOC)和UV254的平均去除率分别提升19. 2%、10. 4%和23. 0%.水厂原水中检出8种多环芳烃(polycyclic aromatic hydrocarbon,PAHs)、16种有机氯农药(organochlorine pesticides,OCPs)、5种卤乙酸(haloacetic acids,HAAs),其总浓度分别为53. 9~100. 0、6. 5~41. 8、2. 5×103~1. 1×104ng·L~(-1),臭氧-生物活性炭深度处理对多环芳烃和有机氯农药的平均去除率分别为32. 5%和25. 9%,比常规处理工艺出水的水质有显著提升.卤乙酸的去除率为33. 8%~87. 0%,主要通过常规处理工艺去除;臭氧-生物活性炭深度处理对氯代乙酸略有去除,溴代乙酸有少量生成.     

低分子量有机酸对岩源磷释放的实验研究

低分子量有机酸是微生物和植物根系分泌物中重要的组成部分.采用浸泡实验比较了4种常见低分子量有机酸(草酸、酒石酸、柠檬酸、苹果酸)对巢湖北岸东部富磷地层中岩源磷的释放量,并对浸提后的部分残渣进行磷的赋存形态分析.结果表明,当有机酸浓度小于5mmol·L-1时,柠檬酸的释磷量最大;大于5mmol·L-1时,草酸和酒石酸的释磷量最大,此时释磷量与有机酸的浓度具有一定的线性关系,其增加趋势远大于浓度小于5mmol·L-1时的增加趋势,而其中草酸和酒石酸又远大于柠檬酸和苹果酸.在有机酸溶液终止pH≥4时,有机酸溶液终止pH与释磷量有较好的线性关系.在50mmol·L-1相同浓度时,草酸对各赋存形态磷转化作用均最大,酒石酸次之.而4种酸对有机磷释放率最大,均高达97%以上,对闭蓄态磷的释放率最小.     

Production of a newly isolated Paenibacillus polymyxa biocontrol agent using monosodium glutamate wastewater and potato wastewater

A phyllosphere bacterial strain EBL-06 was isolated from wheat leaves. The morphology, cultural characteristics, phospholipid fatty acids, physiological and antagonistic fungus activities of this strain were investigated. A phylogenetic tree was constructed by comparing with the published 16S rDNA sequences of the relevant bacteria. The results showed that the isolate EBL-06 was a strain of Paenibacillus polymyxa; this strain performed a high level of antagonistic fungus activity toward a broad spectrum of phytopathogens, such as Botrytis cinerea, Cladosporium cucumerinum, Fusarium spp. The isolate EBL-06 can grow well using monosodium glutamate wastewater (MGW) and potato wastewater (PW) as culture medium. The maximum yield of 6.5 × 10 9 CFU/mL of the isolate EBL-06 anti-fungus biocontrol agent was reached in 15 hr cultivation at 28°C, pH 6.0–7.5 using the mixture of MGW and PW (1:9).     

2种水生植物根际溶液磷素时空变异及有机酸分泌

利用根际土壤溶液的原位抽提和微量样品分析技术,比较了喜旱莲子草(Alternanthera philoxeroides)和香蒲(Typhalatifolia)2种水生植物根际土壤溶液磷素含量的时空变异和根系分泌有机酸种类及数量的差异,从植物吸收磷素、根系分泌有机酸和根际土壤pH值变化等角度探讨了植物磷素高效净化的根际调控机制.结果表明,2种水生植物的根际溶液磷素含量均明显低于非根际溶液;喜旱莲子草的根际溶液磷酸根离子质量浓度(2.53 mg.L-1)显著低于香蒲的根际溶液(5.43mg.L-1)(p<0.05),且喜旱莲子草根系对土壤溶液磷酸根的影响范围大于香蒲.与香蒲相比,喜旱莲子草分泌了较多的苹果酸(浓度27.33μmol.L-1),在活化土壤磷素、促进根系对磷素的吸收方面起了更大的作用.喜旱莲子草吸收磷素的根际效应强于香蒲.     

贵州安顺雨季降水中低分子有机酸研究

为了解贵州安顺地区大气降水中低分子有机酸的化学组成特征, 2007年6～10月共采集降水40次,对降水样品进行了pH值、电导率、水溶性无机阴离子和低分子有机酸的测定.结果表明,安顺地区的大气降水的pH值在3.57～7.09之间,平均值为4.57.最主要的有机酸组成为乙酸、甲酸和草酸,它们的雨量平均浓度依次为6.75、 4.61和2.05 μmol·L^-1.有机酸在6月和7月的浓度明显高于其他月份,表明有机酸可能来源于植物生长释放或者其前驱物的光化学氧化.有机酸对降水自由酸的贡献率平均为32.2%,明显高于贵阳市.同时,甲酸与乙酸和草酸存在显著相关关系（p=0.01）,相关系数分别为0.663和0.503,表明甲酸与乙酸具有相似的来源或者不同来源的相似源强,而草酸的前驱物可能与甲酸具有相似的排放特征.观测期间,安顺地区有机酸的湿沉降通量为2.10 mmol/m²,主要集中在降雨频率和雨量相对较高的夏季,此时有机酸的浓度和有机酸对大气降水自由酸的贡献都较大,因此控制安顺地区夏季有机酸的排放对于此地区的酸雨防治工作显得尤为重要.     

A new process to improve short-chain fatty acids and bio-methane generation from waste activated sludge

As an important intermediate product, short-chain fatty acids(SCFAs) can be generated after hydrolysis and acidification from waste activated sludge, and then can be transformed to methane during anaerobic digestion process. In order to obtain more SCFA and methane,most studies in literatures were centered on enhancing the hydrolysis of sludge anaerobic digestion which was proved as un-efficient. Though the alkaline pretreatment in our previous study increased both the hydrolysis and acidification processes, it had a vast chemical cost which was considered uneconomical. In this paper, a low energy consumption pretreatment method, i.e. enhanced the whole three stages of the anaerobic fermentation processes at the same time, was reported, by which hydrolysis and acidification were both enhanced, and the SCFA and methane generation can be significantly improved with a small quantity of chemical input. Firstly, the effect of different pretreated temperatures and pretreatment time on sludge hydrolyzation was compared. It was found that sludge pretreated at 100°C for 60 min can achieve the maximal hydrolyzation. Further, effects of different initial p Hs on acidification of the thermal pretreated sludge were investigated and the highest SCFA was observed at initial p H 9.0with fermentation time of 6 d, the production of which was 348.63 mg COD/g VSS(6.8 times higher than the blank test) and the acetic acid was dominant acid. Then, the mechanisms for this new pretreatment significantly improving SCFA production were discussed. Finally,the effect of this low energy consumption pretreatment on methane generation was investigated.     

Microbial bioavailability of dissolved organic nitrogen (DON) in the sediments of Lake Shankou, Northeastern China

Dissolved organic nitrogen(DON)extracted from Lake Shankou sediments using KCl was isolated into hydrophobic and hydrophilic fractions.The bioavailabilities of the hydrophobic and hydrophilic fractions to three types of bacterial communities collected from sediments,activated sludge and compost products were examined.The DON recoveries obtained by DAX-8 and cation exchange resins treatment were 96.17% ± 1.58% and 98.14% ±0% for the samples obtained from N4 and N14 stations,respectively.After 25 days of incubation at 25°C,most DON(59% to 96%)was degraded.Hydrophilic DON exhibited a higher reduction rate than hydrophobic DON during the growth phase.Untreated wastewater from Changshuihe town was the main degradable DON source to station N4,and 93% of hydrophilic DON and 80% of hydrophobic DON were degraded.Station N14 received a large amount of refractory DON from forest soils and exhibited DON degradation rates of 82% and 71% for the hydrophilic and hydrophobic fractions,respectively.Amino acid contents and fluorescence intensities were also analyzed.Approximately 27% to 74% of amino acids were taken up by day 5,and their concentration gradually increased in the following days due to the decomposition of dissolved proteins.Parallel factor analysis resulted in identification of tryptophan-like proteins,tyrosine-like proteins and FA-like substances.During the growth phase,40%–51% of the tryptophan-like proteins were taken up by bacteria,and the accumulation of tyrosine-like proteins was attributed to the release of biotic substances.The concentration of the FA-like substances decreased due to microbial decomposition.     

利谷隆在土壤中的吸附过程与机理

利谷隆是一种广泛应用的除草剂。本文研究了它在４种不同理化特性土壤中的吸附过程（平衡吸附所需的时间,土壤ｐＨ的影响及吸附等温线）和在单离子饱和粘土矿物上的吸附机理,结果表明：利谷隆在土壤的吸附强度大（Ｋｔ值在３．８８－９３．８４）;达到吸附平衡的短（５ｈ）;ｐＨ值降低,有利于吸附,ｐＨ在４－６范围内变化较明显;另外,利谷隆在土壤中形成氢键、配位键及离子键是可能的。     

高温/中温两相厌氧消化反应中有机酸的变化

为了深入考察高温／中温两相厌氧消化的反应器系统用以处理混合基质时有机酸的变化特性,采用蒸馏－滴 测定挥发有机酸总量,并在系统达到相对稳定时用色质联机确定有机酸的组成及各自含量。研究结果表明,混合基质经高温消化后挥发有机酸含量有所增加,平均在３４６－５５２９ｍｌ／Ｌ,进一步经中国消化且系统达到稳定后其含量平均为４３－４３３ｍｇ／Ｌ,乙酸,丙酸,丁酸和戊酸是进料混合基质和高温消化后基质中主要有机酸种类