Modification Mechanism of Coconut Husk Activated Carbon Using FeSO4 and Fe(NO3)3

Modification conditions determine the surface topography and the active material phase composition of a catalyst.To study the influence of modification on a carbon-based sorbent,coconut husk activated carbon(AC)which was activated using HNO3 and modified by FeSO4 and Fe(NO3)3 was examined.The pore textures and surface chemical characteristics of the carbon materials were examined by scanning electron microscopy(SEM),Brunner-Emmet-Teller(BET),X-ray diffraction(XRD)and Fourier transform infrared(FTIR)spectroscopy.The surface topography,the pore structure,active materials,and functional groups of AC,AC modificated by HNO3(HNO3/AC for short),and AC modificated by FeSO4 and Fe(NO3)3(Fe/AC for short)were systematically studied.Subsequently,the mechanism of modifying the conditions for the carbon materials was determined.Results showed that the surface micro topography of HNO3/AC became unsystematic and disordered.After modification with FeSO4,the ferriferous oxide was mainly present as a near-spherical crystal.Ferriferous oxides from Fe(NO3)3 modification mainly exhibited a plate shape.HNO3 modification could enlarge the pores but decrease the specific surface area of AC.FeSO4 modification resulted in a new net post structure in the pore canal of AC.Fe(NO3)3 modification caused the pore space structure to develop in the interior,and a higher calcination temperature was useful for ablation.The ash content of the AC was substantially reduced upon HNO3 modification.Upon FeSO4 modification,α-FeOOH,α-Fe2O3 andγ-Fe2O3 coexisted under the condition of a lower concentration of FeSO4 and a lower calcination temperature,and a higher FeSO4 concentration and calcination temperature generated moreα-Fe2O3.The same Fe(NO3)3 modification and a higher calcination temperature were beneficial to the minor chipping formation ofγ-Fe2O3.A higher Fe(NO3)3 loading produced a lower graphitization degree.HNO3 modification formed various new oxygen-containing functional groups and few nitrogen-containing groups.Based on the cover,FeSO4 and Fe(NO3)3 modification could decrease the oxygen-containing and nitrogen-containing functional groups.These results could optimize the modification condition and improve physical and chemical properties of carbon-based sorbents.

Thermogravimetric and Synergy Analysis of the Co-Pyrolysis of Coconut Husk and Laminated Plastic Packaging for Biofuel Production

Unlike plastic,biomass can also be converted and produce high quality of biofuel.Co-pyrolysis of coconut husk(CH)and laminated plastic packaging(LPP)were done in this study.Synergy between these two feedstock was calculated by using thermogravimetric(TGA)and derivative thermogravimetry(DTG)analysis.Different activation energies of the reactions in the co-pyrolysis of CH and LPP were evaluated using the Coats-Redfern method.Results showed an activation energy ranging from 8 to 37 kJ/mol in the different percentage composition of the co-pyrolysis.Also,thermal degradation happens in two-stages in the copyrolysis of CH and LPP,in which CH degrades at the temperature range of 210℃ to 390℃ while LPP degrades in temperatures 400℃-600℃.Co-pyrolysis of CH and LPP can be an alternative for biofuel production and can also reduce the waste problems in the community.

Removal of Methylene Blue, Rhodamine B and Ammonium Ion from Aqueous Solution by Adsorption onto Sintering Porous Materials Prepared from Coconut Husk Waste

The present work was done in order to develop and find out suitable conversion methods for coconut husk wastes into value-added products. It is well-known that coconuts husk waste is hydrophobic therefore ethanol with different doses was used as a surfactant to enhance the removal efficiency. Treated samples at different adsorbent amounts, sintering temperatures & sintering time, stirring time, pH, and solution temperatures for color removal of Methylene Blue (MB) & Rhodamine B (RhB) and ammonium concentration were evaluated by using UV-Visible Spectroscopy. At 300°C, results showed complete removal for MB and more than 75% for RhB, whereas removal of ammonium ion reached around 52% when sintering product from husk waste was used. Further investigation was carried out for ammonium ion to understand the desorption kinetic behaviors and isotherm models. Kinetics indicated that desorption of ammonium ion followed pseudo-first order equation. Adsorption thermodynamic parameters such as ΔG, ΔH, and ΔS followed Van’t Hoff plot for adsorption and found to be negative which indicated that the adsorption process for ammonium onto coconut husk was physical, spontaneous and exothermic.

Nitrate removal from groundwater using chemically modified coconut husk based granular activated carbon:characterization of the adsorbent,kinetics and mechanism

In this study,a highly porous chemically activated granular activated carbon(GAC)was prepared from coconut husk and tested as an adsorbent to remove nitrate from contaminated groundwater.The prepared GAC was characterized by Fouriertransform infrared spectroscopy(FTIR),thermogravimetric and differential thermal analysis(TGA/DTA),scanning electron microscopy(SEM)and the Brunauer-Emmett-Teller(BET)surface area(SBET)analysis.The effects of various process parameters such as initial nitrate concentration,contact time and adsorbent dose on nitrate removal efficiency(response)by the modified GAC were investigated using the statistically significant response surface methodology and Box-Behnken design of experiments.The experimental data were fitted to well-known adsorption isotherms and kinetic models to ascertain the mechanism of the adsorption process.Analysis of variance(ANOVA)was performed to determine the significance of the individual and the interactive effects of process variables on the response.The BET surface area(SBET)and micropore volume of the prepared GAC from coconut husk was 1120 m^(2)/g and 0.392 cm^(3)/g,respectively.The experimental results showed that physisorption was the main adsorption mechanism governing the process,while the rate of adsorption was limited at initial nitrate concentrations>10 mg/L.The Langmuir mono-layer adsorption isotherm best fitted the experimental data with a maximum adsorption capacity of 6.0±1.3 mg/g(~92.5%)with an adsorbent dose of 0.1 g/50 mL,an equilibrium time of 6 h at 28±2℃,and at pH 7.6(±0.2).Among the tested process variables,the adsorbent dose and initial nitrate concentration showed significant effects on the nitrate removal efficiency.

Physicochemical properties of coconut husk activated carbon modified by Fe(N0_(3))_(3)and Mn(N0_(3))_(2)

Fe-loaded activated carbon(AC)has high surface acidity and more active sites,while manganese-loaded AC has high oxygen content.Coconut husk AC modified by Fe-Mn was studied with the aim of revealing the modification mechanism.First,HNO_(3)AC was prepared using the nitric acid immersion method.Second,Fe-Mn/AC was prepared using the Fe(N0_(3))_(3)and Mn(N0_(3))_(2)sequential immersion.The effects of HNO_(3),Fe(N0_(3))_(3),and Mn(N0_(3))_(2)on the pore texture and surface chemical characteristics of carbon materials were examined by scanning electron microscopy,Brunauer-Emmett-Teller(BET)analysis,X-ray diffraction and Fourier-transform infrared spectroscopy.The surface topography,pore structure,active material,and functional groups of AC,HNO_(3)/AC,and Fe-Mn/AC were systematically studied.The following results were obtained.The surface of HNO_(3)AC has more ditches and air voids;the micropores of HNO_(3)AC are deformed and flattened compared to those of AC.The surface of Fe-Mn/AC exhibits an accumulation phenomenon.MnFe_(2)O_(4)and FeMn_(2)O_(4)formed more pore structures.AC and HNO_(3)AC have numerous micropores.The higher loading quantity of Fe-Mn results in bigger specific surface.The active components of Fe-Mn/AC-1,Fe-Mn/AC-2,Fe-Mn/AC-3,and Fe-Mn/AC-4 are MnFe_(2)O_(4),MnO_(0.43)Fe_(2.57)O_(4),Mn_(3)O_(4),and ot-Fe_(2)O_(3)>respectively.The surface functional groups of AC and HNO_(3)AC are oxygen-containing functional groups.The effect of Fe-Mn modifying conditions on functional group species is rare;however,Fe/AC has more oxygen-containing functional groups.These research findings can aid in the desulfurization and denitrification of the Fe-Mn/AC catalyst.

椰糠-黏土植生基材崩解特性试验

以三亚学院校内10~30 cm土层的黏土(过孔径2 mm土壤筛)、直径小于等于2 mm的椰糠为试验材料,以黏土质量为基准,选择占黏土质量0~15%的椰糠、含水率30%~70%,按照正交试验方案设计3组配合比,将黏土、椰糠、水进行充分搅拌混合,装入直径50.46 mm、高50 mm的环刀内制作试块(试验样品);将试块在室内自然环境中分别放置0、1、3、5、7、9 d,利用自制崩解仪进行崩解试验,每隔1 min测定试块在水中的质量(设置最长崩解时间为30 min),计算崩解量(试块崩解的质量占试块初始质量的比例);分析初始含水率、椰糠质量比例、放置时间3个因素对椰糠-黏土植生基材崩解特性的影响。结果表明:不同质量比例的椰糠、黏土、水,搅拌混合后,形成干松、湿润、泌水、泥浆、泥水5种状态。初始含水率、椰糠质量比例、放置时间3个因素协同作用,影响植生基材试块成型后的内部结构,影响崩解现象和最终累计崩解量。初始含水率、椰糠质量比例不同,试块水稳定性形成的机理不同,添加椰糠后,需要增加初始含水率才能使试块形成稳定的内部结构,椰糠质量比例越高,需要的初始含水率则越高。40%、70%初始含水率试块的累计崩解量最高。若初始含水率达到50%,随着椰糠质量比例增加,最终累计崩解量减小;但放置时间达到7 d后,椰糠质量比例超过10%试块的最终累计崩解量反而降低;放置时间少于3 d的试块,试块未全部成型,成型试块放入水中崩解速率较快,5~10 min内大部分试块完全崩解;放置时间达到3 d后,试块放入水中产生吸水现象;放置时间在5~7 d,抗崩解能力达到最大值。综合试验研究结果,建议工程实践中,采用50%~60%初始含水率和10%~13%椰糠质量比例配置制作椰糠-黏土植生基材,此时基材抗崩解性能较好;当边坡刚喷射完基材时必须采取防雨措施。

不同龄期生物炭混凝土力学性能试验研究

将生物炭用于混凝土材料可改善其力学性能,实现固碳的同时丰富了生物质材料固废利用的途径。为研究不同龄期下椰壳、玉米秸秆、稻壳3种生物炭混凝土的工作性能与力学性能,将它以不同质量百分比替代水泥制备生物炭混凝土,对生物碳混凝土的塌落度、基本力学性能展开试验研究。采用SEM和XRD观察生物炭混凝土微观结构与水化产物。结果表明微观结构上生物炭促进了混凝土中水化硅酸钙的生成,水化产物间搭接密实,填充内部孔隙,增加密实程度,进而提升混凝土的宏观力学性能;生物炭可使混凝土7、14 d早期强度显著提升,早期抗压强度最高可提升19.7%,劈裂抗拉强度最高可提升21.7%,抗折强度最高可提升17.3%。

椰糠栽培条件下菠菜施肥配方的筛选

为筛选椰糠栽培条件下适宜的菠菜施肥配方,以椰糠为栽培基质,研究不同施肥处理对菠菜生长发育和品质的影响。结果表明,施用水溶肥14.97 g/m^(2)后,菠菜株高较高,且株幅、单株叶面积均优于其他处理,硝酸盐含量和亚硝酸盐含量均最高。施用有机肥7.49 g/m^(2)后,菠菜叶片数和抽薹率均最高。不同施肥处理对菠菜品质的影响不同,其中施用水溶肥14.97 g/m^(2)、有机肥7.49 g/m^(2)及有机肥22.46 g/m^(2)3个处理菠菜可溶性蛋白含量、叶绿素含量和产量均显著高于清水对照。施用有机肥22.46 g/m^(2),不仅可以显著提高菠菜品质,还可达到较低硝酸盐和亚硝酸盐含量的目标。

不同碳氮比条件下鸡粪和椰糠高温堆肥腐熟过程研究

用鸡粪和椰糠作为基本堆肥原料进行高温堆肥试验,通过控制鸡粪和椰糠的添加量调节堆体初始C/N比,研究其对堆肥过程中堆体温度、p H值、C/N比及养分全量等理化指标的影响,探究鸡粪和椰糠高温堆肥的最适C/N比。结果表明,当C/N比为25时,堆体达到最高温度(57℃),且高温持续时间最长(14 d)。堆肥过程中各处理有机质、全碳、C/N比均呈下降趋势,p H值均呈先上升后下降趋势,全氮和种子发芽指数呈上升趋势。堆肥结束后,堆体F1(初始C/N比为20)、F2(初始C/N比为25)和F3(初始C/N比为30)的C/N比分别为11.13、11.19和10.24,总养分含量w分别为7.94%、8.63%和8.29%,种子发芽指数分别为77.90%、100.65%和93.30%。

竹纤维和椰纤维增强水泥复合材料

本工作采用竹短纤维和椰壳纤维增强水泥，改善水泥基体的韧性和抗裂性，提高了韧度和强度。研究了植物纤维含量、加入乳胶成分和含水量等因素对植物纤维增强水泥复合材料性能的影响，以及植物纤维复合材料的微观破坏。

椰子自动剥衣机的设计

设计一种椰子自动剥衣机,使椰子加工生产时的剥衣工序实现自动化,可降低成本,提高生产效率同时减少人员伤残事故的发生。

不同基质对甜瓜育苗效果的影响

研究了2种基质(椰糠和TS1)对甜瓜幼苗的影响,结果表明,基质TS1(经加工后的椰糠)培养的幼苗各种形态指标(株高,茎粗,地上部和根的鲜、干重,壮苗指数,真叶长度、宽度,子叶长度、宽度和叶绿素含量)显著高于椰糠培养的幼苗。TS1基质有利于甜瓜幼苗的生长。

椰子果皮中营养元素的测定及其种间差异分析

采用原子吸收光谱法对不同品种椰子果皮中8种营养元素进行测定,并分析不同品种间果皮中营养元素含量的差异。对果皮中大量元素的测定结果表明,所选4个品种椰子果皮中K含量最高,Ca含量最低;果皮中Ca含量品种间差异不显著,而K、Na、Mg含量品种间有明显的差异,且有的品种间差异达显著水平。对果皮中微量元素的测定结果表明,4种椰子果皮中Fe含量最高,Mn含量最低;果皮中Mn、Cu、Zn含量品种间有明显的差异,且有的品种间差异达显著水平,而Fe含量品种间差异不显著。本地高种椰子果皮中Mn、Cu、Zn含量均显著低于其他3种椰子。

不同基质配比对甜瓜幼苗生长的影响

以金蜜6号、金海蜜为材料,选用椰糠和沙子为基质,研究了6种不同配比(椰糠∶沙=0∶1,1∶1,2∶1,3∶1,4∶1,1∶0)对甜瓜幼苗生长的影响。结果表明,在所采用的不同基质配比中,椰糠∶沙为2∶1的处理不仅有利于提高甜瓜幼苗下胚轴粗度和高度、叶面积、地上干质量、壮苗指数,使植株达到较为理想的生长状态,而且可以提高幼苗的叶绿素含量和根系活力。综合考虑甜瓜幼苗的壮苗指数、根冠比、叶绿素b、叶绿素含量及根系活力各因素,椰糠∶沙最佳经济型配比为2.15∶1。

不同填料原料对微生物异位发酵床处理生猪养殖废弃物效果的影响

以微生物异位发酵床填料为研究对象,研究了不同原料填料对生猪养殖废弃物的处理效果,分析了在相同条件下玉米秸秆填料与稻壳和椰壳粉混合物填料在温度、p H、含水量、微生物数量和营养成分变化上的差异。结果表明,稻壳和椰壳粉混合物更容易控制温度的变化,发酵床温度保持在25~54°C,并且其p H变化范围较小,为7.6~8.9,更接近好氧发酵的最适p H值范围。稻壳和椰壳粉混合物填料处理含水量稍低于玉米秸秆填料处理,维持在44%~64%之间。试验结束时,两个处理发酵床填料的p H、TN、TP、TK和有机质等指标均符合国家有机肥标准。

椰糠复合基质对设施大棚番茄栽培的影响

以番茄为试材、纯椰糠为对照,探讨了椰糠、塑料泡沫、珍珠岩3种基质不同配比对设施大棚番茄栽培的影响。结果表明,不同基质配方对番茄各阶段生长存在显著影响。与对照相比,以椰糠∶珍珠岩∶泡沫=2∶1∶1的基质配方栽培效果最佳,果实硝酸盐含量最低,Vc含量最高,植株株高、茎粗、叶片数等形态指标有显著提高,产量最高。

不同椰衣栽培介质对西瓜苗生长及生理特性的影响

研究不同的椰衣栽培介质对西瓜发芽的影响等,对于开展椰衣栽培介质基质化的应用具有重要意义。采用海南3市(县)5镇的11种椰糠为基础及配置2种(MIX1、MIX2)复合基质为测试材料,对椰衣介质13个处理的浸出液分别进行西瓜种子发芽实验、西瓜苗生长实验及相关生理测评等。结果表明:复合基质处理能保证西瓜苗生长,pH、EC值的大小是筛选优良椰衣复合基质的关键。椰衣介质MIX1处理是适宜西瓜生长发育的复合基质。

椰糠在不同氮源发酵过程中养分变化规律的研究

以烘干鸡粪、尿素、磷酸氢二铵等作为氮源,调整椰糠发酵堆(椰糠基质)的碳氮比为30:1,并添加酵素菌进行短期发酵,研究椰糠基质在添加不同氮源发酵后的养分含量变化规律。结果表明:(1)发酵后椰糠基质的有机质含量均呈动态下降的趋势,其中以纯鸡粪为氮源的A、H处理的有机质含量下降最多。(2)发酵后椰糠基质的全氮、速效氮、速效磷的含量,以C、F、E、B、D等含化肥氮源的处理较高;速效钾的含量,以A、H两个以纯鸡粪为氮源处理的含量较高,以E、D两个以部分鸡粪为氮源处理的次之。(3)从发酵后椰糠基质的养分含量分析来看,以C(100%磷酸二氢氨-氮)、E(33.3%鸡粪-氮+33.3%尿素-氮+33.3%磷酸氢二铵-氮)、F(50%尿素-氮+50%磷酸二氢氨-氮)处理发酵后的养分含量较高,为椰糠基质发酵的优良配方。

椰子剥衣机自动上下料装置

结合一种椰子剥衣机的设计,对椰子剥衣机自动上下料装置工作原理进行研究,设计由料斗控制椰子有序掉落,旋转滚筒实现椰子的"摆正",机械手完成椰子的抓取,以及装置的自动控制系统,并进行实验验证。结果表明:设计的椰子剥衣机自动上下料装置可行,实现了全过程的自动化且效率高,能满足椰子剥衣机的送料要求。

基于MC9S12XS128的插剥式椰子剥衣机控制系统设计

针对插剥式椰子剥衣机自动化程度低的问题,基于MC9S12XS128单片机设计了椰子剥衣机的电气控制系统。该电气系统包括硬件电路和软件程序两个方面,给出了主控板电路、电源电路等部分的设计方案。在此基础上,结合剥衣机的流程给出软件程序。以MC9S12XS128单片机为核心,通过对其内部电位的控制,完成对步进电机的启停、速度、转向及运行时间的控制,最终自动完成椰子剥衣的整个过程。实验证明,该电气系统运行平稳,剥衣效果良好。该方案设计合理,自动化程度高,可以在实际生产中推广应用。