Nanocrystalline Zeolite Y: Synthesis and Heavy Metal Removal

Lead (Pb) and chromium (Cr) are common groundwater contaminants at industrial installation. Zeolites are widely use as an adsorbent in heavy metal removal. Nanocrystalline zeolite Y has been synthesised from a clear solution at 1500C by using aluminum isopropoxide (Al(OiPr)3 and Ludox LS as alumina and silica source, tetramethylammonium hydroxide (TMAOH) and tetramethyl ammonium bromide (TMABr) as first and second organic template, respectively. The products were characterised by X-Ray Diffraction (XRD) and Scanning Electron Microscopy (SEM) to identify the structure and particle sizes. After 48 hours synthesis time, nanocrystalline zeolite Y samples were obtained with approximately average particle sizes of 268 and 119 nm for one and two organic templates, respectively. The synthesized nanocrystalline zeolite Y was applied for some metal adsorption including Pb(II) and Cr(III) and the results show that the nano crystal samples have good performance. The removal efficiency for Pb and Cr could be up to 88.97% depending on the initial concentration and temperature. The adsorption isotherms of Cr and Pb were determined from the Langmuir and Freundlich equations. The equilibrium sorption capacities (Qe) from the Langmuir equation were 270.27 mg/g and 204.08 mg/g at 300C for Pb and Cr, respectively. Kinetic adsorption analysis of nanozeolite Y shows that the pseudo second order kinetics would be better for fitting the dynamic adsorption of both Cr and Pb cations.Key words: adsorption isotherms, kinetic adsorption analysis, nanocrystalline zeolite

MOBILITAS UNSUR LOGAM PADA HABITAT MANGROVE DAN KORELASINYA DENGAN LIMBAH INDUSTRI DAN KUALITAS TAMBAK

Changing Mangrove shore land into farms and settlements, resulting in further degradation of coastal environments. Some cases which arise due to the high metal pollution can not be reduced by mangroves. Changes in mangrove environmental improvements will decrease the accumulation of metals, because it has obtained data that mangroves are able mengabsorb fires resulting in lower metal solubility in water. The study aimed to assess the metal content in some mangrove and pond habitats, studying the feasibility or the quality of maintenance of sediment ponds for milkfish, and determine the relationship between the quality of sediment by the end of biomass production (PROD), dense stocking density (STD) and survival rate (SR) as well as changes quality of water

ANALISA BIAYA PEMBUATAN MOLD PRINTER DENGAN METODE QUALITY FUNCTION DEPLOYMENT DI PT. INDONESIA EPSON INDUSTRY

Pertumbuhan pesat pada penggunaan produk plastik terutama hasil dari injection molding di industri manufaktur sangat berguna dan memiliki nilai ekonomis yang tinggi. Injection molding banyak dipilih karena memiliki beberapa keuntungan diantaranya, kapasitas produksi yang tinggi, sisa penggunaan material (useless material) sedikit dan kebutuhan tenaga tergolong minimal. Metode perancangan yang dipilih adalah quality function deployment yang bertujuan menganalisa biaya pembuatan mold printer baru tahun 2014 di PT. Indonesia Epson industry. Produk plastik pada model printer Deniro mencapai 47% dari keseluruhan komponen atau part di dalam 1 model printer, sedangkan untuk komponen yang lain yaitu, press parts 18%, shaft 11%, rubber, spring dan others parts mencapai 20%. Dari spesifikasi tersebut didapatkan kesimpulan bahawa komponen part plastik merupakan peluang yang besar untuk aktifitas efisiensi, karena semakin banyak mold maka semakin banyak investasi yang harus dikeluarkan, oleh karena itu perlu dilakukan perancangan konsep untuk efisiensi. Perancangan yang diajukan adalah perubahan dari standard mold menjadi family mold, konsep rangcangan part dan mold dibahas pada saat proses part design review dan mold design review. Kata kunci: injection molding, rancangan, efisiensi

Studi Eksperimental Kekuatan Struktur Atap Berongga Berbahan Komposit Serat Alam

Komposit adalah suatu bahan yang terbentuk dari gabungan dua bahan atau lebih sehingga bahan komposit yang dihasilkan memiliki sifat dan karakteristik mekanik yang berbeda dengan bahan penyusunnya, serat yang digunakan dalam komposit matrik dibedakan menjadi dua yaitu serat alam dan serat sintetik. Sedangkan padi dan nanas merupakan tumbuhan yang banyak dijumpai di seluruh nusantara khususnya indonesia, sehingga hasil alam seperti beras dan nanas di indonesia sangat melimpah. Sekam padi merupakan bahan alternatif yang dapat digunakan dalam pembuatan material komposit, demikian pula serat daun nanas yang akan digunakan sebagai bahan atap merupakan cara yang baik untuk mengurangi evolusi limbah alam seperti sekam padi dan serat daun nanas. . Pada penelitian ini, penulis akan melakukan percobaan kekuatan mesin berbasis komposit menggunakan sekam padi dan serat daun nanas khususnya pada pembuatan atap hollow. Dari uji tarik yang telah dilakukan pada komposit serat sekam padi dan serat daun nanas dengan perbandingan komposisi resin 70% : 30% sekam padi dan daun nanas, 80% : 20% dan 90% : 10%. Terlihat komposisi bahan 90% : 10% mendapatkan nilai lebih tinggi yaitu 101,4 kgf/mm2, sedangkan untuk uji perbandingan perbandingan komposisi resin adalah 70% : 30% sekam padi dan serat daun nanas 80% : 20% dan 90% : 10%. Terlihat bahwa komposisi material 90% : 10% mendapatkan nilai yang lebih tinggi yaitu 1246,26 kgf/mm2

Adsorption of Cu (II) Heavy Metal From Acid Mine Drainage Using Modified Bentonite With Risk Husk Activated Carbon

Abstract: Acid mine drainage is a waste product of the mining process that contains several heavy metals, including copper. The purpose of this study was to develop bentonite adsorbent-modified activated carbon from rice husks that will be used to adsorb Cu metal from acid mine drainage. Bentonite was chemically activated with HCl, whereas rice husk was physically and chemically activated in a furnace at 500°C for 2 hours and soaked in HCl. The modification was accomplished by combining activated bentonite and rice husk activated carbon in variations of ratio, which are 1:1, 1:2, 1;3, 1:4, and 1:5. Morphological analysis revealed a surface structure similar to that of coral (sponge). The functional groups identified include the OH, OH2, Al, SiO, SiOAl, and SiOSi functions. The XRD analysis showed a diffractogram at 2θ = 19000o and 20000o that indicates the presence of montmorillonite minerals. The Cu metal adsorption capacity of rice husk-modified bentonite was 3.153 mg/g. The adsorption isotherm obtained in this study is the Freundlich isotherm, with an R2 value of 0.9541. These findings indicate the potential usefulness of the modified adsorbent in mitigating the environmental impact of the industry dealing with acid mine drainage.Abstrak: Air asam tambang merupakan limbah hasil proses penambangan yang mengandung beberapa logam berat, diantaranya tembaga. Tujuan penelitian ini adalah mengembangkan karbon aktif termodifikasi adsorben bentonit dari sekam padi yang akan digunakan untuk mengadsorpsi logam Cu dari air asam tambang. Bentonit diaktivasi secara kimia dengan HCl, sedangkan sekam padi diaktivasi secara fisik dan kimia dengan tanur pada suhu 500°C selama 2 jam dan direndam dalam HCl. Modifikasi dilakukan dengan menggabungkan bentonit aktif dan karbon aktif sekam padi dengan variasi perbandingan 1:1, 1:2, 1;3, 1:4, dan 1:5. Analisis morfologi mengungkapkan struktur permukaan yang mirip dengan karang (spons). Gugus fungsi yang teridentifikasi meliputi fungsi OH, OH2, Al, SiO, SiOAl, dan SiOSi. Analisis XRD menunjukkan difraktogram pada 2θ = 19000o dan 20000o yang menunjukkan adanya mineral montmorillonit. Kapasitas adsorpsi logam Cu pada bentonit termodifikasi sekam padi adalah 3,153 mg/g. Isoterm adsorpsi yang diperoleh pada penelitian ini adalah isoterm Freundlich, dengan nilai R2 sebesar 0,9541. Temuan-temuan ini menunjukkan potensi kegunaan adsorben yang dimodifikasi dalam mengurangi dampak lingkungan bagi industri yang berurusan dengan limbah air tambang asam

Response Surface Methodology Approach to the Optimization of Cyclone Separator Geometry for Maximum Collection Efficiency

A Response surface methodology coupled with a Box-Behnken design experiment has been utilized to optimize geometry parameters of a cyclone as a gas-solid separator in an effort to obtain a maximum particle collection efficiency. Independent variables being optimized include seven geometry parameters of inlet height (a/D), inlet width (b/D), vortex finder height (S/D), vortex finder diameter (De/D), total cyclone height (Ht/D), cylinder height (h/D), and cone tip diameter (Bc/D). A number of 62 treatments were performed following Box-Behnken experimental design of seven factors and three levels (-1, 0 and +1). The response variable, the cyclone collection efficiency, was calculated in accordance with the Muschelknautz model using a spreadsheet software. The relationship between the response variable and independent variables was mathematically expressed according to a quadratic polynomial equation calculated with the aid of Design Expert software.  The results of the research showed that among seven variables being investigated, there are only five cyclone geometry parameters which significantly affected the cyclone collection efficiency, including inlet height (a/D), inlet width (b/D), vortex finder height (S/D), vortex finder diameter (De/D) and total cyclone height (Ht/D).  The optimization was then conducted to include these five variables that significantly affected the collection efficiency and neglected the remaining other two variables.  The optimization computation was run in the Design Expert statistical software by setting a maximum possible value for the collection efficiency. The maximum collection efficiency of 91.244% was obtained when the independent variables of inlet height a/D=0.8, inlet width b/D=0.38, vortex finder height S/D=0.69, vortex finder diameter De/D=0.575 and total cyclone height Ht/D=3.12.  Validation of this statistical finding was tested again and compared with the result of Muschelknautz model calculation to give a significantly small error of 0.82%

Analysis of the potential of landfill gas as an alternative for electrical energy source

Municipal solid waste (MSW) is generated from human activities, where most of them end up at the landfill. The landfill gas produced from the degradation of organic matter in the MSW landfill contains methane can be used as the energy source. Therefore, the objective of this research is to analyze the potential of landfill gas as an alternative for energy source. Two Landfill Simulator Reactor (LSRs) made of high density polyethylene (HDPE) pipe has 50 cm outside diameter and 150 cm of height were operated under natural condition. The first LSR was operated without leachate recirculation (A), while the other one was operated with leachate recirculation (B). Results of this research found the highest methane concentration from LSR A was about 53% and 41.8% from LSR B. This finding was applied to estimate the landfill gas production for electricity generation in Cot Padang Nila landfill. The potential electrical energy that could be produced from Cot Padang Nila landfill is 203 MWh/year if it is operated using LSR A mode, and 161 MWh/year when operated in accordance to LSR B mode. This amounts of energy is suitable to provide electricity for 53-67 households in the vicinity of the landfill

Comparative analysis of HHV and LHV values of biocoke fuel from palm oil mill solid waste

This research aims to investigate and compare the energy value of different biocoke and raw palm oil-biomass. Applying pressure and heating simultaneously during biocoke production is a direct method used in this research. The results of the proximate analysis showed that the water content in each sample tested was below 10%. The water content can be reduced to 5% for all samples except oil palm-midrib. The highest raw biomass heating value was recorded from palm-kernel-shell at 16.83 MJ/kg; the lowest oil palm-midrib was 14.60%. Meanwhile, the highest lower heating value was recorded from biocoke at 19.08 MJ/kg, and the weakest empty-fruit-bunches 17.01 MJ/kg

Analysis of turbulence and surface growth models on the estimation of soot level in ethylene non-premixed flames

Soot prediction in a combustion system has become a subject of attention, as many factors influence its accuracy. An accurate temperature prediction will likely yield better soot predictions, since the inception, growth and destruction of the soot are affected by the temperature. This paper reported the study on the influences of turbulence closure and surface growth models on the prediction of soot levels in turbulent flames. The results demonstrated that a substantial distinction was observed in terms of temperature predictions derived using the k-ε and the Reynolds stress models, for the two ethylene flames studied here amongst the four types of surface growth rate model investigated, the assumption of the soot surface growth rate proportional to the particle number density, but independent on the surface area of soot particles, ƒ(As) = ρNs , yields in closest agreement with the radial data. Without any adjustment to the constants in the surface growth term, other approaches where the surface growth directly proportional to the surface area and square root of surface area, ƒ(As) = As and ƒ(As) = √As, result in an under- prediction of soot volume fraction. These results suggest that predictions of soot volume fraction are sensitive to the modelling of surface growth

Modellierung des biochemischen Abbaus des organischen Kohlenstoffs in Siedlungsabfalldeponien

Abweichender Titel laut Übersetzung der Verfasserin/des VerfassersZsfassung in dt. SpracheTitel auf dem Einband: Modeling the transformation of degradable and refractory organic carbon in municipal solid waste landfillsDie Deponierung von Siedlungsabfällen stellt eine wichtige, durch den Abbau organischer Substanz bedingte Quelle von langfristigen Umweltbelastungen dar. Zahlreiche Autoren haben deshalb die Transformationen von Abfällen in Deponien zur Bestimmung zukünftiger Emissionen untersucht. Allerdings gibt es nur wenige Studien, in denen berücksichtigt wird, dass organische Kohlenstoffverbindungen unterschiedliche Persistenzen aufweisen. Das Ziel dieser Arbeit ist die Entwicklung eines Modells zum Abbau organischen Kohlenstoffs in Siedlungsabfalldeponien unter Berücksichtigung unterschiedlicher Persistenz sowie von Deponieparametern wie Temperatur, pH Wert, Sickerwasserrezirkulierung und klimatischen Bedingungen. Der Modelansatz besteht in der Kombination eines diskontinuierlichen Reaktors mit einem Festbettreaktor. Die organische Substanz wird als feste Matrix behandelt, Gas- und Flüssigphase fließen im Gegenstrom durch den porösen Festkörper. Der Abbau der organischen Substanz wurde parallel für drei unterschiedlich refraktäre organische Kohlenstofffraktionen unter der Annahme von dreistufigen sequentiellen biochemischen Reaktionen (Acidogenese, Acetogenese, Methanogenese) modelliert. Alle biochemischen Reaktionsschritte und resultierenden chemischen Spezifizierungen wurden mit C++ und einem Windows Userinterface programmiert. Das Model wurde anhand von (i) fremden Daten und Resultaten eines Labordeponiesimulationsreaktors, sowie (ii) eigenen Feldmessdaten der Deponie Breitenau validiert und optimiert. Die Resultate der Modellierung stimmten mit denjenigen aus Experiment und Feld recht gut überein: In den ersten 17 Jahren wurden 100% des leicht abbaubaren Kohlenstoffs, 3.5% des schwerer abbaubaren Kohlenstoffs sowie kein persistenter Kohlenstoff abgebaut. Die Modellsensitivität bezüglich Einflussgrößen des Abbaus wurde anhand verschiedener Simulationen ermittelt. Innerhalb der geprüften Intervalle hatte die Temperatur im Deponiekörper den größeren Einfluss auf den Abbau organischer Substanz als der pH Wert oder die Sickerwasserrezirkulation. Die Modellierungsergebnisse erlauben Schlussfolgerungen für den Deponiebetrieb hinsichtlich Gestaltung und Verkürzung der kostspieligen Nachsorge.Landfilling of municipal solid waste (MSW) represents an important source of long-term emissions due to the degradation of organic matter. Hence, numerous generic studies have been carried out to explore the transformation of landfilled wastes for assessing future environmental loadings. However, specific investigations into the behavior of organic carbon, taking into account the substantial variability in persistence to degradation, are rare. Thus, the objective of this study was to develop a model for the degradation of organic carbon in MSW landfills, taking into account different refractory levels of organic matter as well as landfill parameters such as temperature, pH, leachate recirculation, and climatic conditions. In order to create a suitable model, two approaches based on the batch reactor and the packed bed reactor principles were combined. The solid organic matter was assumed as a fixed-state matrix, while the gas and liquid phases were considered counter-current flows through the solid matrix. The degradation of organic matter was modelled in parallel for three differently degradable organic carbon fractions, assuming sequential three-stage biochemical reactions (acidogenesis, acetogenesis, and methanogenesis). All biochemical reaction steps and species were encoded using a C++ object oriented program under a Windows user interface. The model was tested and improved by employing (i) data and results from an existing laboratory landfill simulation reactor, and (ii) field data from the Breitenau land-fill. Modelling and field results corresponded reasonably well: Of the readily degradable organic carbon, about 100% are degraded during the first 17 years, while of the slowly degradable only 3.5%, and none of the refractory carbon are transformed. Several simulations were performed to analyze the model sensitivity with regards to parameters influencing the degradation. It appears that within the boundaries of this study, landfill body temperature has a more profound effect on the degradation of organic matter than pH or leachate recirculation. The modeling results allow conclusions about operation and management of landfills with regard to shortening the expensive landfill after care.24