酚酸类物质对水华藻类的化感作用及其机理

研究了酚酸类物质阿魏酸和对羟基苯甲酸对水华鱼腥藻(Anabaena flos-aquae)以及蛋白核小球藻(Chlorella pyrenoidosa)的化感抑制作用及其机理.结果表明,对羟基苯甲酸浓度为0.6mmol/L,阿魏酸浓度为1.0mmol/L时,对水华鱼腥藻和蛋白核小球藻均有明显的抑制作用,其中对羟基苯甲酸的化感抑制作用较阿魏酸显著,对水华鱼腥藻的抑制作用比对蛋白核小球藻显著.其抑制作用表现为藻细胞生长量以及藻细胞叶绿素a含量下降、细胞内超氧阴离子自由基增高以及膜脂质过氧化产物丙二醛(MDA)积累、细胞超氧化物歧化酶(SOD)的活力和比活力开始时应激性升高.推测酚酸类物质化感抑制作用的机理可能与自由基的产生以及膜脂质过氧化增加引起膜结构的破坏、细胞功能受损有关.2种酚酸类物质联合用时具有协同抑藻效应.     

Pyrolysis of rice husk and sawdust for liquid fuel

The paper is focused on studying how to convert rice husk and sawdust into liquid fuel. Rice husk, sawdust and their mixture were pyrolyzed at the temperature between 420℃ and 540℃, and the main product of liquid fuel was obtained. The experimental result showed that the yield of liquid fuel heavily depended on the kind of feedstock and pyrolysis temperature. In the experiments, the maximum liquid yields for rice husk, sawdust and their mixture were 56% at 465 ℃, 61% at 490℃ and 60% at 475℃ respectively. Analysis with GC-MS and other apparatus indicated that the liquid fuel is a complicated organic compound with low caloric value and can be directly used as fuel oil without any up-grading. As a crude oil, the liquid fuel can be refined to be vehicle oil.     

Application of malt residue in submerged fermentation of Bacillus subtilis

Malt residue is a common waste or byproduct from beer industries after brewing and milling of malted barley. In this work, Bacillus subtilis RB14 was used to study the microbial growth and production of secondary metabolites like lipopeptide antibiotic iturin A in the malt residue for its effective recycling. B. subtilis RB14 could grow in submerged fermentation of malt residue and significant growth (10⁹ CFU/mL) was observed without any supplementation. In submerged fermentation iturin A production using malt residue was about 170 mg/L, which was found to be higher than its production in No.3 (Polypepton, glucose, KH₂PO₄, MgSO₄·7H₂O) medium where production was about 120 mg/L. More than 600 mg/L of iturin A production was observed when malt residue was combinedly used with No.3 medium. This production was significantly higher than their summation of their individual production. However, the growth of B. subtilis in combined medium was found to be similar to that of the submerged fermentation in simple malt residue. Therefore, the remarkable enhancement in production of iturin A in supplemented malt residue was attributed to the nutrients supplied from No.3 medium.     

Kinetics and isotherms of Neutral Red adsorption on peanut husk

Adsorption of Neutral Red (NR) onto peanut husk in aqueous solutions was investigated at 295 K. Experiments were carried out as function of pH, adsorbent dosage, contact time, and initial concentration. The equilibrium adsorption data were analyzed by Langmuir, Freundlich, Temkin, Dubinin-Radushkevich, and Toth isotherm models. The results indicated that the Toth and Langmuir models provided the best correlation of the experimental data. The adsorption capacity of peanut husk for the removal of NR was deter...     

富含中、微孔稻壳活性炭的表征及液相吸附性能

对采用CO2-NaOH联合活化新工艺制备的稻壳活性炭的孔结构进行了表征,并用探针分子亚甲基蓝、苯酚考察了它对大、小分子的液相吸附性能.结果表明:所得活性炭同时富含中孔与微孔,中、微孔容积均达到0.32cm3/g,各占总孔容的50%;它对苯酚及亚甲基蓝均显示出优越的吸附性能,脱除效率分别达到94%和99%,超过或接近所用优质商业活性炭的相应值;对这2种污染物的吸附皆较好地符合Langmuir等温式.     

Removal of elemental mercury by iodine-modified rice husk ash sorbents

Iodine-modified calcium-based rice husk ash sorbents(I2/CaO/RHA) were synthesized and characterized by X-ray diffraction,X-ray fluorescence,and N2 isotherm adsorption/desorption.Adsorption experiments of vapor-phase elemental mercury(Hg0) were performed in a laboratory-scale fixed-bed reactor.I2/CaO/RHA performances on Hg0 adsorption were compared with those of modified Ca-based fly ash sorbents(I2/CaO/FA) and modified fly ash sorbents(I2/FA) .Effects of oxidant loading,supports,pore size distribution,iodine impregnation modes,and temperature were investigated as well to understand the mechanism in capturing Hg0.The modified sorbents exhibited reasonable effciency for Hg0 removal under simulated flue gas.The surface area,pore size distribution,and iodine impregnation modes of the sorbents did not produce a strong effect on Hg0 capture effciency,while fair correlation was observed between Hg0 uptake capacity and iodine concentration.Therefore,the content of I2 impregnated on the sorbents was identified as the most important factor influencing the capacity of these sorbents for Hg0 uptake.Increasing temperature in the range of 80-140°C caused a rise in Hg0 removal.A reaction mechanism that may explain the experimental results was presumed based on the characterizations and adsorption study.     

酚类化合物雌激素效应的比较研究

采用重组人雌激素受体基因片段(hER)及共激活因子(GRIP1)双杂交酵母检测体系,检测9种酚类物质的类雌激素和抗雌激素效应.结果表明,所检测的化合物中有3种同时表现出雌激素诱导与抑制活性;2种只表现出雌激素诱导活性;1种只表现出雌激素抑制活性;3种均没有雌激素诱导与抑制活性.结构分析表明:酚类中产生雌激素活性的物质具有取代基位于对位且邻位没有大的取代基团的结构;烷基在对位的酚类物质也能显示出雌激素拮抗活性.所采用的双杂交酵母检测体系适用于外源物质的雌激素活性检测,具有较高的灵敏度;结合外源物的雌激素诱导与抑制活性,用于分析污染物的体内作用方式.     

Effect of chemical and thermal activations on the properties of rice husk ash-based solidified wastes

Strength development,leachability and microstructure of heavy metals from the solidified waste using synthesis rice husk ash (sRHA) and lime blended at the weight ratio of 1:1 were used as binders.The heavy metal-containing sludge was used at the level of 0 wt.%,30 wt.%,and 50 wt.% dry weight,respectively.The sample specimens with and without 1.5 wt.% of sodium silicate (SiO 2 /Na 2 O=1.0) were cured under the ambient condition and elevated temperature curing at 50°C for 24 hr.Experimental results showed that the introduction of sodium silicate solution and elevated temperature curing to sRHA-based solidified waste containing 30 wt.% of heavy metal sludge gave one day strength of 20 kg/cm 2 compared to 0.9 kg/cm2 for the control sample.XRD patterns indicated that most metal-sulfides present in the sludge were appeared in the solidified waste and SEM coupled with EDX techniques reveal these metal-sulfide particles were trapped within the lime-sRHA matrices.In addition,cumulative leaching behavior by tank test (EA NEN 7375:2004) showed that solidified waste containing up to 30 wt.% of heavy metal sludge was suitable to dispose in a secured landfill.     

核桃青皮生物炭对重金属铅、铜的吸附特性研究

采用500℃限氧裂解法将农林废弃物核桃青皮制成核桃青皮生物炭,进行了核桃青皮生物炭对铅、铜的批量吸附实验.同时,利用扫描电镜、FTIR红外等方法探讨了核桃青皮炭吸附Pb~(2+)、Cu~(2+)的特性,探究了吸附时间、溶液初始浓度、吸附温度、吸附剂投加量、溶液初始pH等因素对核桃青皮生物炭吸附Pb~(2+)、Cu~(2+)作用的影响,讨论了吸附动力学特性及吸附等温特性.结果表明:温度298.15 K、pH为3~6条件下,核桃青皮生物炭吸附Pb~(2+)和Cu~(2+)在20 min内即可达到吸附平衡,核桃青皮炭最佳投加量分别为0.8、1.5 g·L~(-1),最大吸附量分别为476.190、153.846 mg·g~(-1);吸附过程符合准二级动力学方程,等温吸附曲线符合Langmuir方程,说明其吸附过程主要是近似单分子层的化学吸附.     

Preparation and characterization of activated carbon foam from phenolic resin

Activated carbon foam was successfully prepared from phenolic resin synthesized with phenol and formaldehyde under alkali condition. The influence of process variables, such as steam rate, carbonization temperature, carbonization time, activation temperature and activation time on the adsorption capacities of the activated carbon foam was studied. Under the optimum experimental conditions, the activated carbon foam with a specific surface area 727.62 m²/g was obtained. Moreover, the iodine value and carbon tetrachloride value of the activated carbon foam was 1050.28 mg/g and 401.37 mg/g, respectively. The pore size of the activated carbon foam was in the range of 3.5–5 nm which was determined through the N₂ adsorption test. In addition, the yield of the activated carbon foam was 36.24%. The result of scanning electron microscopy (SEM) showed that the activated carbon foam became honeycomb structure, and its pore wall was thinner and smoother compared to the unactivated carbon foam.     

苯酚与苯胺衍生物对发光菌的联合毒性

 应用微板毒性分析方法,以污染物对淡水发光菌——青海弧菌(Vibrio-qinghaiensis sp.)Q67 的发光抑制为毒性指标,分别测定了对氯苯酚(P1)、邻氯苯酚(P2)、2,4-二氯苯酚(P3)、间甲苯酚(P4)、对甲苯酚(P5)、间硝基苯酚(P6)、2-硝基苯酚(P7)、对甲苯胺(P8)、P9、邻硝基苯胺(P10)、邻氯苯胺(P11)、间氯苯胺(P12)对Q67 的毒性. 结果表明, 12 种污染物的剂量-效应关系除了P11 可用Logit 模型描述外,其余11 种污染物均可用Weibull 模型有效描述. 由模型估算的半数效应浓度负对数值(pEC50) 分别为3.43,2.81,3.66,2.83,2.99,3.15,3.20,2.52,2.36,3.66,2.81,2.89,其对Q67 的毒性大小顺序为 (P3 = P10) > P1 > P7 > P6 > P5 > P12 > P4 > (P11 = P2) > P8 > P9. 分别设计浓度为各自EC10 和EC50 的2 个等效应浓度比混合物和12 个均匀设计浓度比混合物进行微板毒性实验,并应用剂量加和(DA)模型与独立作用(IA)模型建立由单一毒物的剂量-效应参数来预测混合物联合毒性的方法. 结果表明,在实验浓度范围内各混合物毒性均能用DA模型精确预测.     

钱塘江水系中酚类化合物的浓度水平及污染特征

用SPE法富集、HPLC测定了钱塘江水系中苯酚、3-甲基苯酚、4-硝基苯酚、2,4-二氯苯酚和2,4,6-三氯苯酚5种溶解态酚类化合物的浓度.结果表明,5种酚类化合物总浓度为0.54～19.90μg/L,平均浓度为4.05μg/L;苯酚的平均浓度为2.06μg/L,占5种酚类化合物总平均浓度的50.7%;各河段酚类化合物的平均浓度从上游至下游呈下降趋势,支流金华江中5种酚类化合物平均浓度为10.2μg/L,是干流中的近4倍.苯酚可作为钱塘江水系中酚类化合物污染的代表物,苯酚浓度(x)与5种酚总浓度(y)间显著正相关(y=0.980+1.491x),R²为0.88.     

酚类化合物在矿化垃圾中的吸附性能与结构相关性研究

采用静态吸附方法,对8种酚类化合物在矿化垃圾中的吸附行为进行了研究,并用Langmuir和Fieundlish等温吸附方程对其进行了拟合.研究结果表明,8种代酚的吸附能力大小顺序为3-甲基酚＞4-甲氧基酚＞4-氯酚＞2,4-二氯酚＞3-硝基酚＞4-硝基酚＞2-氯酚＞苯酚.对8种酚类化合物Langmuir和Frendlich等温吸附方程常数和18个量子化学参数采用PLS进行逐步回归分析,得到了以Frendlich方程参数lnκ为因变量的数学模型.该模型表明,有机酚在矿化垃圾中的吸附性能主要与有机酚分子的疏水性和极性有关.而且该模型得到的预测值与实测值接近,说明利用PLS进行回归处理得到的模型较为合理、能有效地预测有机酚类化合物在矿化垃圾中的吸附行为.     

污泥-稻壳协同焚烧对污泥磷资源回收效率的影响

污水处理厂污泥中含有丰富的营养元素磷,回收其中的磷在一定程度上能缓解磷资源的衰竭。利用焚烧法处理污泥,以稻壳作为添加物,采用Hedley逐级提取法和酸浸出法考察污泥-稻壳焚烧灰中磷的形态和浸出效果的变化,并探讨稻壳添加量对焚烧灰中磷形态的影响。结果表明：当稻壳添加量为总质量的50%时,磷的生物可利用性最高;响应曲面法优化结果表明,最佳试验条件是HCl浓度、浸出时间和液固比分别为0.33 mol/L,6.4 h和50 mL/g,该条件下,磷的浸出率达93%,与污泥焚烧灰相比提高了20%;比较污泥灰、稻壳灰及污泥-稻壳混烧灰的理化性质可知,污泥-稻壳协同焚烧并未改变污泥灰和稻壳灰的主要组分,但出现了新的物相,形貌也发生了一定变化。污泥-稻壳协同焚烧能提高焚烧灰中磷的浸出率,从而有利于从污泥中回收磷资源。

     

Effective removal of phosphorus from high phosphorus steel slag using carbonized rice husk

High phosphorus steel slag and carbonized rice husk are two common wastes characterized by high generation and low secondary use values.Through the reduction of high phosphorus steel slag by biomass,both wastes were fully utilized,thus reducing the negative impact on the environment.In this study,variables such as temperature,time,and amount of reactants were changed to determine the optimal conditions for the reaction of steel slag with carbonized rice husk at high temperatures.The actual amoun...     

Pollutant emission characteristics of rice husk combustion in a vortexing fluidized bed incinerator

Rice husk with high volatile content was burned in a pilot scale vortexing fluidized bed incinerator. The fluidized bed incinerator was constructed of 6 mm stainless steel with 0.45 m in diameter and 5 m in height. The emission characteristics of CO, NO, and SO2 were studied. The effects of operating parameters, such as primary air flow rate, secondary air flow rate, and excess air ratio on the pollutant emissions were also investigated. The results show that a large proportion of combustion occurs at the bed surface and the freeboard zone. The SO2 concentration in the flue gas decreases with increasing excess air ratio, while the NOx concentration shows reverse trend. The flow rate of secondary air has a significant impact on the CO emission. For a fixed primary air flowrate, CO emission decreases with the secondary air flowrate. For a fixed excess air ratio, CO emission decreases with the ratio of secondary to primary air flow. The minimum CO emission of 72 ppm is attained at the operating condition of 40% excess air ratio and 0.6 partition air ratio. The NOx and SO2 concentrations in the flue gas at this condition are 159 and 36 ppm, which conform to the EPA regulation of Taiwan.     

NaOH和沼液浸泡预处理对麦糠厌氧发酵的强化作用比较

采用浓度分别为2%、4%、6%、8%的NaOH在80 ℃下预处理麦糠2 h,鸡粪和牛粪沼液在25 ℃下预处理麦糠5 d,比较NaOH和沼液浸泡预处理对麦糠厌氧发酵的强化作用。结果表明:6%NaOH获得最大产甲烷潜力,为199.5 mL/g,比对照组增加了191.2%(68.5 mL/g),且消化时间仅为6 d;鸡粪沼液的预处理效果明显优于牛粪沼液,最大产甲烷潜力达130.8 mL/g,相当于2%NaOH的预处理效果,但无需额外添加化学或生物等预处理药物。因此,在应用中可以根据实际情况,灵活选择2种预处理方式。     

酚类化合物的生物吸附特征与其结构关系

选用经处理过的盐泽螺旋藻为吸附剂,研究其对10种酚类化合物的吸附行为。结果表明：盐泽螺旋藻对苯酚、邻苯二酚、对苯二酚、邻氨基酚、对氯酚和2,4-二氯酚6种酚均有不同程度的吸附,用Freundlich和Langmuir吸附等温方程描述时,均呈现良好的线性关系;该6种酚的吸附常数k的对数值与其分子连接性指数（²X^v）呈良好的线性关系;盐泽螺旋藻对其余4种酚（邻甲酚、间羟基酚、间氨基酚、间乙酰氨基酚）均不产生吸附。     

稻壳生物炭对污染土壤中稀土元素生物有效性的影响

利用农业秸秆制备了污染土壤修复材料稻壳生物炭和稻壳灰,在模拟稀土（REE）污染的酸性土壤中,添加0、5%和10%的稻壳灰（RHA）稻壳生物炭（RHB）,通过栽培实验考察RHA和RHB对REEs的形态和生物有效性的影响.春秋两季的盆栽实验结果表明,RHA和RHB的添加有效的降低了稀土的弱酸可提取态,随着添加量的增加效果越明显,10% RHA和10% RHB土壤中REEs的弱酸（乙酸）提取态较对照组分别降低了31.65%、19.915%,弱酸可提取态转化为了可还原态,与对照组相比,RHA和RHB的土壤中稀土元素的可还原态分别增加了26.367%、10.321%.两种修复材料显著降低了胡萝卜和茼蒿对稀土元素的富集,10% RHA处理组胡萝卜和茼蒿REEs含量分别较对照组降低了98.08%、93.41%,10% RHB胡萝卜和茼蒿REEs含量分别较对照组降低了68.61%、66.75%.研究结果表明,稻壳生物炭和稻壳灰的施用,能够有效的改善污染土壤的理化性质,降低稀土元素生物可利用态的含量,从而遏制植物对稀土元素的富集.