Catalytic Hydrothermal Liquefaction of Water Hyacinth Using Fe3O4/NiO Nanocomposite: Optimization of Reaction Conditions by Response Surface Methodology

This research aimed at optimizing the reaction conditions for the catalytic hydrothermal liquefaction (HTL) of water hyacinth using iron oxide/nickel oxide nanocomposite as catalysts. The iron oxide/nickel oxide nanocomposite was synthesized by the co-precipitation method and used in the hydrothermal liquefaction of water hyacinth. The composition and structural morphology of the synthesized catalysts were determined using X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), and atomic absorption spectroscopy (AAS). The particle size distribution of the catalyst nanoparticles was determined by the Image J software. Three reaction parameters were optimized using the response surface methodology (RSM). These were: temperature, residence time, and catalyst dosage. A maximum bio-oil yield of 59.4 wt% was obtained using iron oxide/nickel oxide nanocomposite compared to 50.7 wt% obtained in absence of the catalyst. The maximum bio-oil yield was obtained at a temperature of 320°C, 1.5 g of catalyst dosage, and 60 min of residence time. The composition of bio-oil was analyzed using gas chromatography-mass spectroscopy (GC-MS) and elemental analysis. The GC-MS results showed an increase of hydrocarbons from 58.3% for uncatalyzed hydrothermal liquefaction to 88.66% using iron oxide/nickel oxide nanocomposite. Elemental analysis results revealed an increase in the hydrogen and carbon content and a reduction in the Nitrogen, Oxygen, and Sulphur content of the bio-oil during catalytic HTL compared to HTL in absence of catalyst nanoparticles. The high heating value increased from 33.5 MJ/Kg for uncatalyzed hydrothermal liquefaction to 38.6 MJ/Kg during the catalytic HTL. The catalyst nanoparticles were recovered from the solid residue by sonication and magnetic separation and recycled. The recycled catalyst nanoparticles were still efficient as hydrothermal liquefaction (HTL) catalysts and were recycled four times. The application of iron oxide/ nickel oxide nanocomposites in the HTL of water hyacinth increases the yield of bio-oil and improves its quality by reducing hetero atoms thus increasing its energy performance as fuel. Iron oxide/nickel oxide nanocomposites used in this study are widely available and can be easily recovered magnetically and recycled. This will potentially lead to an economical, environmentally friendly, and sustainable way of converting biomass into biofuel.

葡萄风信子花序色彩公众喜好度评价

【目的】以17个种和栽培品种的葡萄风信子为材料,研究其花序色彩的公众喜好度。【方法】基于美景度评价法(SBE),采用网络问卷调查的形式,收集公众对葡萄风信子花序色彩的喜好度,并计算其SBE标准化值,提取影响公众喜好度的主要评价因子,建立评价模型。【结果】葡萄风信子花序色彩SBE值13个分值在0分以上,评价员对其表现较为普遍的积极态度(喜欢或很喜欢),不同性别、专业的评价员审美也具有相对一致性。经过向后(Backward)筛选因子建立模型:SBE=1.632+0.597X1-0.017X10+0.047X11-0.064X13。通过模型得到了影响葡萄风信子花序色彩公众喜好度的4个因子,分别为色彩鲜艳感(X_(1))、色相对比度(X_(10))、明度对比度(X_(11))和花序冠幅(X_(13)),这4个评价因子与公众喜好度呈极显著线性关系。各因子对葡萄风信子花序色彩公众喜好度的贡献率由大到小排序为:明度对比度>色彩鲜艳感>花序冠幅>色相对比度。【结论】葡萄风信子花序色彩的公众积极态度频率与SBE值均可体现公众喜好度变化趋势。SBE法适用于葡萄风信子花序的色彩评价,可以拓宽其应用领域。

水葫芦(Water hyacinth)深度净化猪粪便污水研究

为了探索深度净化猪粪便污水的方法 ,对水葫芦 (Waterhyacinth)深度净化猪粪便污水的效果进行了研究。结果表明 ,水葫芦对猪粪便污水有很好的净化效果 ,在不影响水葫芦生长的前提下 ,单位面积水体生长的水葫芦越多去除禽畜粪便污水COD和NH+ 4 N的效果越好 ,在直径 4 0cm的塑料盆内种植 4 7～ 1 4 0g水葫芦 ,COD和NH+ 4 N去除率分别为 4 8.9%～ 5 8.1 %和 81 .4 %～ 89.9% ;当初始CODcr约为 2 0 0mg/L时 ,水葫芦去除污水CODcr的效果最好 ,去除率为 70 .9% ;在初始污水NH+ 4 N为 34.5～ 1 0 2 .5mg/L范围时 ,初始NH+ 4 N浓度越低效果越好 ,去除率为 90 .7%～ 81 .7% 。

不同水质条件对水葫芦生长的影响研究

为探究影响水葫芦滋生的主要水质条件,采集兴化市河道内水葫芦,经室内纯水预培养,置入7种不同氮磷浓度水质条件的培养皿中。通过定期采集水葫芦样本的生物量、叶片数、根系长度生理指标,分析不同水质对水葫芦生理指标的影响,探讨不同水质条件下水葫芦的生长发育特征,为水葫芦的综合治理提供科学依据。

Ultrafast Spectral Studies of the Primary Processes of Photosynthesis in Spinach and Water Hyacinth Leaves

The authors have studied the spectroscopic characteristics and the fluorescence lifetime for the chloroplasts from spinach (Spinacia oleracea L.) and water hyacinth (Eichhornia crassipes (Mart) Solms.) plant leaves by absorption spectra, low temperature steady_state fluorescence spectroscopy and single photon counting measurement under the same conditions. The absorption spectra at room temperature for the spinach and water hyacinth chloroplasts are similar, which show that different plants can efficiently absorb light of same wavelength. The low temperature steady_state fluorescence spectroscopy for the water hyacinth chloroplast reveals a poor balance of photon quantum between two photosystems. The fluorescence decays in PSⅡ measured at the natural Q A state for the chloroplasts have been fitted by a three_exponential kinetic model. The slow lifetime fluorescence component is assigned to a collection of associated light harvesting Chl a/b proteins, the fast lifetime component to the reaction center of PSⅡ and the middle lifetime component to the delay fluorescence of recombination of P + 680 and Pheo -. The excited energy conversion efficiency (η) in PSⅡ RC is 87% and 91% respectively for the water hyacinth and spinach chloroplasts calculated on the 20 ps model. This interesting result is not consistent with what is assumed that the efficiency is 100% in PSⅡ RC. The results in this paper also present a support for the 20 ps electron transfer time constant in PSⅡ RC. On the viewpoint of excitation energy conversion efficiency, the growing rate for the water hyacinth plan is smaller than that for the spinach plant. But, authors' results show those plants can perform highly efficient transfer of photo_excitation energy from the light_harvesting pigment system to the reaction center (approximately 100%).

葡萄风信子愈伤组织再生体系的构建

以葡萄风信子常见种亚美尼亚的花蕾和叶片作为外植体,开展不同因素对葡萄风信子愈伤组织诱导和植株再生影响的研究。结果表明:亚美尼亚的花蕾和叶片愈伤组织诱导和增殖的最佳培养基配方为:MS+1.0 mg/L 2,4−D+0.1 mg/L 6−BA,其愈伤组织诱导率为100%,且继代35 d后不同培养基上的花源和叶源愈伤组织的鲜质量无显著差异;液体培养和光照培养有利于愈伤组织细胞增殖,1 g亚美尼亚花源和叶源愈伤组织经液体培养4个继代周期后,平均鲜质量最高可达(10.36±1.13)g和(10.55±2.29)g,表明不同培养基配方对亚美尼亚花蕾和叶片愈伤组织细胞增殖无显著影响,且液体培养和光照培养均有利于愈伤组织的增殖;胚性和非胚性2种愈伤组织分别通过体细胞胚发生和器官发生2种途径可再生形成完整植株,再生率均为100%。

“走近黑天鹅”生态道德教育实践活动的实施策略

在建设生态文明国家背景下,利用地域资源开展黑天鹅治理水葫芦的生态道德教育实践活动。在学生兴趣和初步探究成果的基础上,指导学生确定探究课题,以不同食量梯度的水葫芦作为自变量,设置黑天鹅实验区和对照实验区进行实验,分析不同条件下水葫芦的减重率和黑天鹅的增重率并得出结论。本次活动学习内容具有生成性,以实践和探究为主,让学生能运用所学解决生态保护问题。

指向核心素养培育的实验设计与教学实践——以“探秘入侵生物水葫芦”为例

本文选用入侵生物水葫芦,设计了旨向情境中问题解决的系列实验及跨学科学习任务,引导学生经历发现问题、提出假设、设计实验、实施实验、结果分析、得出结论到新的研究这一完整的探究过程。并在完成跨学科学习任务的过程中参与社会性科学议题的讨论。结果显示,该系列实验能激发学生探究兴趣,发展科学思维;学生能综合运用多学科概念、思路和方法解决实际问题。

水葫芦微波热解特性的实验研究

水葫芦具有较高氢碳比,微波热解是其转化为清洁能源和高附加值化学品的有效方法。本文对水葫芦微波催化热解的特性进行较为系统的研究。实验结果表明:热解温度对生物油和热解气的总产率具有显著影响。随着温度的升高,生物油和热解气的产率增加,在600℃时达到最大。水葫芦的微波热解产物焦油中主要包含大量单环芳香族化合物和醇类化合物等,轻气体主要是氢气和一氧化碳。升温速率对水葫芦微波热解产物的产率和组分具有影响,随着升温速率的提高,半焦的产率增加,生物油的产率降低。较快的升温速率也有利于直链烃和一氧化碳的生成。

浅层型湖泊水葫芦去除营养物质的研究

湖泊中的氮磷等营养物质主要来自生活污水、农业废水、化肥等加工过程产生的工业废水,这些污染废水未经处理或处理不达标直接排入湖泊,使水体中营养物质增多,氮磷营养物质超过富营养化发生浓度,易造成湖泊呈现富营养化,促使自养型生物特别是藻类等浮游生物的个体数量迅速增多。本文对水葫芦对水体中氮、磷以及氨氮等营养物质的去除效果,以及覆盖率差异下水葫芦对氮、磷及氨氮的去除规律进行了分析,为探讨水葫芦抑藻机理奠定了基础。

Adsorption of Caffeine and Ciprofloxacin onto Pyrolitically Derived Water Hyacinth Biochar： Isothermal, Kinetic and Thermodynamic Studies

In this work, the adsorptive features of water hyacinth （Eichhornia crassipes） derived biochar for sequestration of ciprofloxacin and caffeine from aqueous solution is reported. The isothermal behaviour, adsorption kinetics, mechanisms and thermodynamic parameters were investigated in batch mode. Langmuir and Freundlich models described the equilibrium adsorption data with regression values 〉 0.9. The kineticsdata obeyed the pseudo-second-order kinetic law while intraparticle pore diffusion was not the only rate controlling step. The computed thermodynamic parameters, namely change in Gibbs free energy （AG）, change in enthalpy （AH） and change in entropy （AS） indicated that the adsorption processes were spontaneous and exothermic with less randomness, pH dependence studies depicted multi-mechanistic adsorption for both compounds and is hypothesized to involve hydrophobic interactions besides other non-coulombic interactions. The findings demonstrate that water hyacinth biochar presents an excellent low cost and environmentally benign adsorbent for mitigation of pharmaceuticals from water with a removal efficiency of above 60 % for caffeine and ciprofloxacin.

Performance of a water hyacinth(Eichhornia crassipes)system in the treatment of wastewater from a duck farm and the effects of using water hyacinth as duck feed

Nowadays, intensive breeding of poultry and livestock of large scale has made the treatment of its waste and wastewater an urgent environmental issue, which motivated this study. A wetland of 688 mz was constructed on an egg duck farm, and water hyacinth （Eichhornia crassipes） was chosen as an aquatic plant for the wetland and used as food for duck production. The objectives of this study were to test the role of water hyacinth in purifying nutrient-rich wastewater and its effects on the ducks＇ feed intake, egg laying performance and egg quality. This paper shows that the constructed wetland removed as much as 64.44% of chemical oxygen demand （COD）, 21.78% of total nitrogen （TN） and 23.02% of total phosphorus （TP）. Both dissolved oxygen （DO） and the transparency of the wastewater were remarkably improved, with its transparency 2.5 times higher than that of the untreated wastewater. After the ducks were fed with water hyacinth, the average daily feed intake and the egg-laying ratio in the test group were 5.86% and 9.79% higher, respectively, than in the control group; the differences were both significant at the 0.01 probability level. The egg weight in the test group was 2.36% higher than in the control group （P 〈 0.05）, but the feed conversion ratios were almost the same. The eggshell thickness and strength were among the egg qualities significantly increased in ducks fed with water hyacinth. We concluded that a water hyacinth system was effective for purifying wastewater from an intensive duck farm during the water hyacinth growing season, as harvested water hyacinth had an excellent performance as duck feed. We also discussed the limitations of the experiment.

Invasion and control of water hyacinth (Eichhornia crassipes)in China

By the time of primary 21st century, water hyacinth had become a serious environmental problem in China. Water hyacinth contributes to the major part of ecological hazards from the invasion of foreign plant species, which is estimated about USD 7 billion a year in values. In the past 10 years, herbicides glyphosate, 2,4-D and paraquat have been used in controlling water hyacinth in China. Al- though the herbicides provided effective control on the weed in some areas, they could not provide the sustainable inhibition on the weed population, while would lead to pollution on water at various levels. At present, the herbicide application on water hyacinth is forbidden in many areas of China such as Shanghai. In this situation, the asexual reproduction inhibitor, KWH02, was invented for controlling water hyacinth and it provided about 70% of growth inhibition without any risk of dead plant pollution. It has been about 10 years for bio-control of water hyacinth in China. Works focused on mainly the efficacy and safety of the utilization of foreign insects. Researches on microorganism herbicides to control water hyacinth were started and obtained primary achievements in recent years. Although there are different opinions on how to face the water hyacinth problem in China, it is accepted widely that the control methods should be high efficient and safe with low cost. Some practical measures for integrated management of water hyacinth are suggested.

Anatomical studies on water hyacinth (Eichhornia crassipes (Mart.) Solms) under the influence of textile wastewater

Water hyacinth (Eichhornia crassipes (Mart.) Solms) is a prolific free floating aquatic macrohpyte found in tropical and subtropical parts of the earth. The effects of pollutants from textile wastewater on the anatomy of the plant were studied. Water hyacinth exhibits hydrophytic adaptations which include reduced epidermis cells lacking cuticle in most cases, presence of large air spaces (7～50 μm), reduced vascular tissue and absorbing structures. Textile waste significantly affected the size of root cells.The presence of raphide crystals was noted in parenchyma cells of various organs in treated plants.

Can Water Hyacinth Clean Highly Polluted Waters? —A Short Paper for Discussion

Recently local government and environmental protection authorities in China have turned to the water hyacinth, one of the world’s worst aquatic weeds, to reduce nutrient concentrations in highly eutrophic lake waters, especially in Lake Dian in southwestern China’s Yunnan Province. Although we do not reject using water hyacinth to reduce lake eutrophication, it is not a complete solution. In our view, a more complete solution requires a holistic consideration of watershed or drainage characteristics, and a solid understanding of the limnological features of individual lakes. Before the bio-geochemistry and toxicological effects of water hyacinth be thoroughly understood, applying it widely to lake restoration and overstating its practical value is not only irresponsible but also dangerous.

Experimental Research on the Application of Water Hyacinths to the Ecological Restoration of Water Bodies with Eutrophication

[Objective] The study aims to discuss the application of water hyacinths to the ecological restoration of water bodies with eutrophication through simulation experiments. [Method] In this study, water hyacinths were used to restore the simulated eutrophic water with green algae as the dominant algae species, and then the restoration effect of the simulated eutrophic water by water hyacinths was analyzed. [Result] In the simulation test without sediment, the peak chlorophyll concentration was 434.6 mg/m3 in the tank without water hyacinths, which decreased to 285 and 119 mg/m3 respectively in the tanks with 1 and 4 water hyacinths. In the experiment with sediment, compared with the control tank without water hyacinths, a 58% reduction in chlorophyll concentration could be observed in the tank with 4 water hyacinths planted (with a coverage of 51%). The results showed that water hyacinths could inhibit alga growth notably, but there was likely a density threshold (51% coverage), and no significant eco-restoration effect was observed in the simulated eutrophic water with too few water hyacinths planted. [Conclusion] The research could provide scientific references for the ecological restoration of eutrophic water bodies.

Biogas Production Using Water Hyacinth (Eicchornia crassipes) for Electricity Generation in Kenya

Water hyacinth, E. crassipes, an invasive water weed thrives in fresh water bodies causing serious environmental problems. In Kenya the weed has invaded Lake Victoria and poses great socioeconomic and environmental challenges. Currently the weed is harvested from the Lake and left in the open to rot and decay leading to loss of aesthetics, land and air pollution. There is therefore need for development of value addition and economic exploitation strategies. The aim of the study is to assess the potential for utilization of the weed as a renewable energy resource for biogas production. Samples were collected from Lake Victoria, pulped and blend with cow dung at a ratio of 3:1 as inoculum. The resultant mixture was mixed with water at a ratio of 1:1 and fed into a 6 m3 tubular digester. The digester was recharged with 20 kg after every three days. The temperature, pH variations, gas compositions, upgrading and gas yields were studied. The temperature ranged between 22.8°C - 36.6°C and pH 7.4 - 8.5. Biogas was found to contain 49% - 53% methane (CH4 ), 30% - 33% carbon dioxide (CO2 ), 5% - 6% nitrogen (N2 ) and traces of hydrogen sulphide (H2S). The biogas was upgraded using solid adsorbents and wet scrubbers increasing the methane content by up to 70% - 76%. The upgraded gas was used to power internal combustion engines coupled with an electricity generator and direct heat applications. The study concludes that E. crassipes is a potential feedstock for biogas production especially in areas where it is abundant.

Sorption of Manganese （II） and Chromium （III） Ions from Aqueous Solution Using Water Hyacinth Biomass （Eichhornia crassipes）

The use of water hyacinth biomass as adsorbent for Cr3＋ and Mn2＋ ions from aqueous solution by means of batch-adsorption technique was investigated to determine the potential ability of the biomaterial for metal ion removal. The equilibrium isotherm study showed that the maximum monolayer coverage on the biomass surface was 0.933 mg·g-1 and 0.874 mg·g-1 for Mn2＋ and Cr3＋ ions respectively. The highest percentage of Cr3＋ and Mn2＋ ions adsorbed by the biomass was 86.4% and 82.6% at the optimum pH of 4.0 and 6.0 respectively. The results also showed that the highest percentage removal 82.5% and 78.3% was obtained at 30 and 20 minutes respectively for Cr3＋ and Mn2＋ ions. The sorption process was examined by means of the Langmuir model. The adsorption equilibrium data were found to follow the Langmuir isotherm model with high coefficients of determination （R2 = 0.990 and 0.999） for Cr＋ and Mn2＋ ions respectively. The adsorption capacity of water hyacinth showed that water hyacinth will be useful in recovering chromium （III） and manganese （II） ions from solution and their subsequent removal from industrial effluents.

Extraction and Application of Natural Mordant Dyes from Eichhornia Crassipes(Water Hyacinth)

Metallic salts are often added as extra mordant when dyeing the fabrics with natural dyes. Eichhornia crassipes,namely water hyacinth( WH),is an environmentally problematic aquatic weed with high affinity for metals. In this paper,WH was selected as the source of natural mordant dyes,and extracted by absolute ethyl alcohol using a soxhlet apparatus. The colorants in WH were extracted and separated by column chromatography and thin layer chromatography( TLC). UV-visible spectrophotometer( UV-VIS),mass spectrometry, chemical identification with chromogenic reaction,and Fourier transform infrared spetroscopy( FTIR) were used to identify the main components of each pigment band. The total metal contents before and after extracting of the WH were determined by using an inductively coupled plasma atomic emission detector. The WH extracts were then used to dye wool fabric. The dyeing properties of WH extracts with and without metal mordant were investigated and compared. The results show that the main components of WH extracts are pheophytin and phyllins. The major metallic elements identified in WH are magnesium, manganese,zinc,and iron. Samples dyed with WH extracts without metal mordant exhibits high K / S values and good dyeing properties. This study indicates that the WH extracts can be used as a natural mordant dye on wool fabrics directly.

Integrated biological control of water hyacinths, Eichhornia crassipes by a novel combination of grass carp, Ctenopharyngodon idella (Valenciennes, 1844), and the weevil, Neochetina spp.

The efficacy of grass carp Ctenopharyngodon idella （Cyprinidae） and weevils Neochetina spp. （Curculionidae） to control the aquatic weed, water hyacinth, is investigated in a square net cage （happas） setting at a farm in Cuddalore District, South India. This novel combination of insects and fish is found to be superior to individual treatments for controlling the weed growth within ll0 d. The biomass of the weed, number of plants, percentage of flowered plants and chlorophyll contents were studied. The weed biomass is reduced from 5 kg （day 1） to 0.33 kg （day 110） when exposed to grass carp and weevils. The number of plants is reduced to 0.75 in grass carp and weevil exposed happas, while it is 741.5 in the control. The mean number of leaves per plant is also reduced. In addition, the chlorophyll a and b are significantly reduced in happas exposed to the combination of fish and insects when compared to the other treatments. Based on the results of this study, we consider the combined use of grass carp and weevils to be more efficient and sustainable for managing water hyacinths than the use of these organisms individually.