Characterization of coffee residues pellets and their performance in a residential combustor

Spent coffee grounds (SCG) and coffee husks (CH) were evaluated as biofuels, after densification, for energy production. CH represent a specific problem for the coffee industry due to a low calorific value, high ash content, and a very low bulk density. Hence, the energetic potential of SCG (95 wt%)/CH (5 wt%) blend and pure SCG (100%) were examined. The blend of SCG and CH was limited to 5 wt% of CH because of the low bulk density of CH. Therefore, physicochemical and energetic characterizations of the produced pellets were performed. Thermogravimetric analyses were performed under nitrogen and air atmospheres to evaluate the CH behavior in the blend. Characterization study shows that both produced pellets could reach the French Agropellets standard (AQI). Thermal degradation showed that the mean reactivity of the SCG/HC pellets was higher than pure SCG. Then, combustion experiments were performed in a domestic combustor, after modification of the boiler power in order to improve its energetic performances. The presence of CH led to a rise of CO, NOx, VOC’s, and particle emissions. Nevertheless, the performances of the biofuels are almost in agreement the NF EN 12809 standard.     

密相塔半干法烟气脱硫塔内加湿降温及其对脱硫效率的影响

为了实现密相塔半干法脱硫工艺的精确加湿进一步提高系统脱硫效率,利用推导出的传热传质计算方法,得到烟气温度降低和加水量的关系.结合3组密相塔半干法工程实际数据,发现理论计算值和实测值误差区间仅为2.9％ ～5.4％.通过选取河北某钢厂210 m2烧结烟气密相塔半干法脱硫项目实际在线检测数据,发现循环脱硫灰含湿量为3％的系统脱硫效率整体高于含湿量为5％和4％的样品,最大值达93.56％.通过粒度分析、扫描电镜、X射线衍射及差热-热重对2种不同含湿量的循环脱硫灰进行表征,结果表明,含湿量为3％的循环脱硫灰较含湿量为5％的样品粒径小、比表面积大,无团聚现象,物相分析还证实相对于含湿量为5％样品,其Ca(OH)2和结晶水含量少,几乎都是CaSO4和CaS03干态物质,因此脱硫反应进行彻底,脱硫效率较高.     

磁性生物膜载体的规模化制备、表征和应用

利用机械力化学表面改性原理设计了卧式双旋搅拌混合反应设备,通过磁铁矿粉和适量浓硫酸的球磨混合反应制备得到磁性生物膜载体,其XRD、IR、SEM和BET表征分析结果表明,磁性生物膜载体表层生成了多羟基硫酸铁为主的活性组分.进而在膜生物反应器实验装置中投加磁性生物膜载体进行了中试实验,结果表明,磁性生物膜载体能与活性污泥中的微生物聚合形成稳定的菌胶团,活性污泥SV30从实验初期89％降到了稳定期的39％,此外,磁性生物膜载体还具有稳定膜生物反应池出水COD,强化脱氮除磷的能力.     

滦河水体溶解性有机物的综合分级表征及其混凝去除过程

天然水体溶解性有机物(DOM)是微污染物的潜在载体,是消毒副产物的主要前驱物,自身又可能成为微污染物,因此研究其内在特性和去除机理有着重要的基础性科学意义.本研究综合利用化学、物理分级方法(即树脂和超滤分级法),对中国北方典型饮用水源--滦河水体的DOM进行全面分级表征.此水体DOM基本化学分级特征是憎水酸(HoA)、亲水性物质(HiM)含量较高,且具有季节稳定性;其物理分级特征是分子量＜1 kDa及3 kDa～10 kDa的组分含量较高,也表现出一定的时间稳定性.选用工业聚合铝(PAC)研究此DOM的基本混凝特征和内在混凝机理,结果表明,强憎水部分HoA及3 kDa～10 kDa间的有机物较易被去除,而较大分子量范围10 kDa～30 kDa间的有机物去除率较低,说明混凝过程中此DOM的物理性质不起主要作用,而化学性质更为重要.特别对DOM各组分作进一步(结合)分级研究,发现HoA主要在＞10 kDa范围.＜1 kDa的有机物中主要为HiM,但其中还含有HoA和弱憎水酸(WHoA),这使特定条件下部分＜1 kDa有机物被混凝去除成为可能.另外,HoA中按分子量大小仍可分为易去除和难去除部分,但分布不连续,易去除部分在3 kDa～10 kDa和＞30 kDa区间,而其10 kDa～30 kDa部分较难去除,说明可能存在其他结构性影响因素,值得深入研究.     

Isolation, characterization and phylogenetic analysis of a bacterial strain capable of degrading acetamiprid

An aerobic bacterium, capable of degrading the new chloronicotine pesticide acetamiprid, was isolated from the sludge of pesticide factory after successive enrichment cultures and named strain FH2 which is a Gram-negative, rod-shaped, obligate aerobic org     

Using multivariate regression modeling for sampling and predicting chemical characteristics of mixed waste in old landfills

Municipal solid waste landfills pose a threat on environment and human health, especially old landfills which lack facilities for collection and treatment of landfill gas and leachate. Consequently, missing information about emission flows prevent site-specific environmental risk assessments. To overcome this gap, the combination of waste sampling and analysis with statistical modeling is one option for estimating present and future emission potentials. Optimizing the tradeoff between investigation costs and reliable results requires knowledge about both: the number of samples to be taken and variables to be analyzed.This article aims to identify the optimized number of waste samples and variables in order to predict a larger set of variables. Therefore, we introduce a multivariate linear regression model and tested the applicability by usage of two case studies. Landfill A was used to set up and calibrate the model based on 50 waste samples and twelve variables. The calibrated model was applied to Landfill B including 36 waste samples and twelve variables with four predictor variables.The case study results are twofold: first, the reliable and accurate prediction of the twelve variables can be achieved with the knowledge of four predictor variables (Loi, EC, pH and Cl). For the second Landfill B, only ten full measurements would be needed for a reliable prediction of most response variables. The four predictor variables would exhibit comparably low analytical costs in comparison to the full set of measurements. This cost reduction could be used to increase the number of samples yielding an improved understanding of the spatial waste heterogeneity in landfills.Concluding, the future application of the developed model potentially improves the reliability of predicted emission potentials. The model could become a standard screening tool for old landfills if its applicability and reliability would be tested in additional case studies.     

拜耳法赤泥粒径分级预处理的研究

赤泥是从铝土矿中提取氧化铝的过程中产生的工业废渣.分析了拜耳法赤泥的粒径分布,以及主要化学组成和矿物组成在不同粒径赤泥中的变化规律.在此基础上,提出先将赤泥粒径分级预处理,然后根据粗细粒径赤泥的差异分别进行回收利用的思路.研究结果表明,赤泥中粒径大于0.075 mm的粗颗粒以铁、硅、钙为主,实践证明可以通过磁选或重选工...     

1，4-二氯苯降解菌的分离及其降解特性研究

从某污水处理曝气池的活性污泥中分离出一株能够以1,4-二氯苯为唯一碳源和能源生长的菌株DEB-1,通过形态特征和生理生化试验初步鉴定为黄杆菌属（Flavobacterium sp.）。实验结果表明,该菌株最适降解温度为32℃、最适降解pH为7.8,24 h对100 mg/L的1,4-二氯苯的降解率达94.5%。菌株DEB-1的降解谱较广,对5种氯苯类物质具有较高的降解率。并进一步研究了DEB-1的1,4-二氯苯降解酶粗酶液的性质,其最适反应温度和pH分别为30℃和8.5。对处理含氯代芳香化合物的有机废水具有一定的意义。     

羟基铝及复合改性蒙脱石对As(V)的去除性能

采用无机羟基铝及阳离子表面活性剂十六烷基三甲基溴化铵对天然蒙脱石进行无机及复合改性。在吸附过程中研究了反应时间、投加量和pH等变量对吸附性能的影响,同时进行吸附动力学及吸附等温线研究,吸附规律符合Langmuir等温方程式。采用X射线衍射、X射线荧光、傅里叶红外光谱等表征手段对未改性及改性蒙脱石进行性能表征。研究结果表明,羟基铝及复合改性蒙脱石对As(V)具有良好的吸附性能,在pH为4～10,初始砷浓度为2 mg/L,改性蒙脱石对As(V)的去除率接近99%。吸附机理主要为羟基铝表面络合吸附和静电吸附。     

In vitro toxicity of fungicides with different modes of action to alfalfa anthracnose fungus,Colletotrichum destructivum

Abstract

Sensitivity of 24 isolates of Colletotrichum destructivum O’Gara, collected from alfalfa plants in Serbia, to eight selected fungicides, was investigated in this study. Molecular identification and pathogenicity test of isolates tested were also performed. Fungicide sensitivity was evaluated in vitro, using mycelial growth assay method. All isolates exhibited significant pathogenicity, causing necrosis at the alfalfa seedling root tips two days after inoculation. Using the primer pair GSF1-SR1 and by comparing the amplified fragments of the tested isolates with the marker (M), the presence of the amplicon of the expected size of about 900?bp was determined for all isolates. The isolates tested in this study showed different sensitivity towards fungicides in vitro. Mycelial growth was highly inhibited by QoI (quinone outside inhibitors) fungicide pyraclostrobin (mean EC₅₀=0.39?µg mL^?1) and by DMI (demethylation-inhibiting) fungicide tebuconazole (mean EC₅₀=0.61?µg mL^?1), followed by azoxystrobin (mean EC₅₀=2.83?µg mL^?1) and flutriafol (mean EC₅₀=2.11?µg mL^?1). Multi-site fungicide chlorothalonil and MBC (methyl benzimidazole carbamate) fungicide thiophanate-methyl evinced moderate inhibition with mean EC₅₀=35.31 and 62.83?µg mL^?1, respectively. Thirteen isolates were sensitive to SDHI (succinate dehydrogenase inhibitors) fungicide boscalid and fluxapyroxad, (mean EC₅₀=0.49 and 0.19?µg mL^?1, respectively), while the rest of isolates were highly resistant.