Emisi Gas Metana dan Karbon Dioksida pada Proses Pengolahan Limbah Cair Kelapa Sawit

Purpose: The purpose of this study was to know, calculate and evaluate the concentration of methane gas and carbon dioxide produced in each wastewater treatment plant (WWTP) pond.Method: This research was a qualitative research, using case study design and explanatory approach. The object of this research was the emission of methane gas and carbon dioxide emitted from 12 WWTP ponds.Results: The highest COD and BOD decrement occurred in pond 4 of 39% COD and 61.2% BOD. The highest total methane gas emission was 1.49 x 109 kg hours-1 (1.49 x 106 tons hour-1) occurring in the morning, while the highest total carbon dioxide emission was 2.59 x 109 kg per hour (2.59 x 106 ton hour-1). Conclusion: The concentrations of methane and carbon dioxide gas produced by each WWTP pool varied greatly depending on temperature, residence time and the amount of mud. Methane gas emissions and carbon dioxide emissions occurred in each WWTP pool with the highest methane gas emission value occurring in pond 3 in the afternoon at 356,64 x 106 mg m-2minute-1 and the highest carbon dioxide emissions occur in pond 3 in the afternoon at 402.145 x 106 mg m-2minute-1. The decrease of COD value in whole anaerobic pool was 52,1% and the decrease of COD value in aerobic pool was 27,2%

Studi Biodegradasi Poli Hidroksi Butirat Dalam Media Cair (Biodegradation of Poly Hydroxy Butyrate in Liquid Medium)

Poly hidroxy butyrate (PHB) is a member of bioplastic group. This type of plastic is expected to be alternative plastic which is environmently friendly to replace synthetic plastic that is known to be very difficult to degrade. This research aims to test the biodegradability of commercial PHB in liquid mediums used activated sludge from waste water treatment plant in plastic synthetic factory. Identification of biodegradation process was done by monitoring the changes of PHB characteristics including visual change, surface morphology change, reduction of weight, reduction of crystallinity, and reduction of molecular weight during 15 weeks incubation. The result shows that the damage of PHB sample during biodegradation could be seen visually and liquid medium show the existence of change which can be seen visually and the surface morphology of PHB changed significantly. Weight reduction, crystallinity reduction, and molecular weight reduction revealed of 22.91%, 57.44%, and 29.52% respectively

Pemodelan Matematis Pengurangan COD Dalam Air Limbah Industri Penyamakan Kulit Secara Adsorpsi Kontinyu Menggunakan Abu Terbang Bagas

The objective of this research was to obtain suitable mathematical model for ChemicalOxygen Demand (COD) removal originated from tannery wastewater using bagasse fly ash incontinuous system. In the column experiment, effect of flowrate, concentration of wastewater,and bulk density were studied. Three models: Adams-Bohart, Thomas, and Yan were applied toexperimental data to predict the breakthrough curve. The best model was evaluated usingcorrelation coefficients. Yan model was found to give the most accurate to describe dynamicbehavior of the column experiment. The best result was obtained at flowrate of 100 mL/min,concentration of 400 mg/L, and bulk density of 61 g/L. The Yan kinetic constant (k ) and the Yadsorption capacity (q ) were 0.3210 mL/mg/min and 17.0947 mg/g respectively and the Ycorrelation coefficient obtained was 0.9379

Pengaruh Ukuran Dan Fraksi Organik Terhadap Kuantitas Dan Kualitas Timbulan Lindi

Timbunan sampah pada landfill (TPA) akan mengalami degradasi dan akan menghasilkan cairan (lindi) baik kuantitas maupun kualitasnya. Kuantitas dan kualitas timbulan lindi dari sampah perkotaan akan dipengaruhi oleh beberapa faktor seperti: komposisi dan karakteristik sampah, kadar air, umur sampah dan kondisi cuaca (iklim). Pada kegiatan studi ini bertujuan untuk mengetahui pengaruh komposisi sampah (jumlah fraksi organik) dan karakteristik sampah (ukuran butiran) terhadap karakteristik timbulan lindi.Dalam rangka untuk mendapatkan tujuan studi, maka metode yang diterapkan adalah melakukan percobaan laboratorium menggunakan reaktor biodegradasi volume 1500 mL. Dalam percobaan ini digunakan dua kelompok reaktor yaitu; kelompok pertama, digunakan untuk pengujian pengaruh persentase fraksi organik, sedangkan kelompok kedua dimaksudkan untuk pengujian pengaruh ukuran butiran sampah terhadap karakteristik lindi.Sebagai parameter kualitas lindi ditentukan TSS, BOD, dan COD, sedangkan parameter kuantitas lindi adalah volume cairan yang keluar dari reaktor. Berdasarkan hasil percobaan diketahui bahwa jumlah (persentase) fraksi organik dan ukuran butiran sampah dapat berpengaruh terhadap karakteristik timbulan lindi. Secara keseluruhan konsentrasi TSS, BOD, dan COD semakin besar sejalan dengan bertambahnya persentase fraksi organik. Hal yang sama terjadi untuk ukuran butiran samaph semakin kecil, maka TSS, BOD, dan COD semakin besar. Adapun volume timbulan lind

Isolasi, Skrining Dan Identifikasi Jamur Xilanolitik Lokal Yang Berpotensi Sebagai Agensia Pemutih Pulp Yang Ramah Lingkungan (Isolation, Screening and Identification Xylanolytic Local Fungi That Potentially as Pulp Bleaching Agents)

Xilanase merupakan enzim yang berfungsi luas dalam bidang industri. Xilanase digunakan sebagai perlakuan awal proses pemutihan kertas di industri pulp dan kertas sehingga dapat mengurangi penggunaan senyawa klorin yang berbahaya bagi lingkungan. Xilanase yang cocok digunakan dalam industri pulp dan kertas seharusnya bebas dari aktivitas selulase. Jamur merupakan salah satu kelompok mikrobia yang mampu menghasilkan xilanase. Penelitian ini bertujuan untuk memperoleh isolat jamur unggul lokal penghasil xilanase dari tanah yang diasumsikan memiliki kandungan xilan tinggi. Tanah di sekitar industri pulp dan kertas; hutan akasia di Kab. Muara Enim dan Ogan Ilir, Sumatera Selatan; hutan Wanagama, Yogyakarta; penggergajian kayu di kota Palembang dan Yogyakarta serta TPA Palembang digunakan sebagai sumber isolat jamur. Berdasarkan skrining awal dalam media basal xilan agar diketahui bahwa dari 111 isolat jamur yang diperoleh, sebagian besar mempunyai potensi menghasilkan xilanase, akan tetapi hanya 12 isolat yang mempunyai kemampuan xilanolitik tinggi. Skrining selanjutnya dilakukan pada media basal xilan cair menunjukkan bahwa jamur yang diidentifikasi sebagai Chaetomium globosum, Penicillium simplicissimum, Aspergillus tamarii dan Monocillium sp. berpotensi unggul dalam menghasilkan xilanase dibandingkan isolat lainnya berdasarkan aktivitas enzim spesifiknya. Keempat jamur tersebut diketahui juga memiliki aktivitas lignolitik dan selulolitik. Oleh karena itu, xilanase yang diproduksi ke empat jamur tersebut berpotensi dikembangkan sebagai agen pemutih pulp

Efficient algorithms to discover alterations with complementary functional association in cancer

Recent large cancer studies have measured somatic alterations in an unprecedented number of tumours. These large datasets allow the identification of cancer-related sets of genetic alterations by identifying relevant combinatorial patterns. Among such patterns, mutual exclusivity has been employed by several recent methods that have shown its effectivenes in characterizing gene sets associated to cancer. Mutual exclusivity arises because of the complementarity, at the functional level, of alterations in genes which are part of a group (e.g., a pathway) performing a given function. The availability of quantitative target profiles, from genetic perturbations or from clinical phenotypes, provides additional information that can be leveraged to improve the identification of cancer related gene sets by discovering groups with complementary functional associations with such targets. In this work we study the problem of finding groups of mutually exclusive alterations associated with a quantitative (functional) target. We propose a combinatorial formulation for the problem, and prove that the associated computation problem is computationally hard. We design two algorithms to solve the problem and implement them in our tool UNCOVER. We provide analytic evidence of the effectiveness of UNCOVER in finding high-quality solutions and show experimentally that UNCOVER finds sets of alterations significantly associated with functional targets in a variety of scenarios. In addition, our algorithms are much faster than the state-of-the-art, allowing the analysis of large datasets of thousands of target profiles from cancer cell lines. We show that on one such dataset from project Achilles our methods identify several significant gene sets with complementary functional associations with targets.Comment: Accepted at RECOMB 201

Studi Metode Penambahan Perak Nitrat Pada Saringan Keramik Terhadap Escherichia Coli Pada Air Minum

Problematika air tercemar mikrobiologis di Yogyakarta berdasar hasil pemantauan rutin oleh Dinas Kesehatan Kota Yogyakarta pada tahun 2011 menunjukkan bahwa pada parameter mikrobiologis terdapat 596 (67%) sumber air bersih (sumur) penduduk belum memenuhi syarat sesuai Permenkes 492/MENKES/PER/IV/2010, demikian juga pada tahun 2010 dan 2009 masing masing 68,8% dan 63,2% dari sampel yang diperiksa, sedangkan untuk pemeriksaan terhadap air perpipaan (PDAM) pada tahun 2011 masih terdapat 8,9 % dari sampel yang tidak memenuhi syarat. Hal tersebut terjadi pada pemukiman padat penduduk yang disebabkan keterbatasan lahan sehingga jarak antara peresapan jamban dengan sumur penduduk kurang dari persyaratan. Penggunaan Filter Keramik sebagai pengolahan air pada tingkat rumah tangga telah banyak dipelajari dan diteliti Riset filter keramik dikembangkan untuk persiapan keadaan darurat bencana dan pemukiman padat penduduk. Penelitian ini dilakukan pada tahun 2013-2014 dengan menggunakan rancangan analitik observasional, dengan pendekatan pre test-postest group design dengan analisis kuantitatif eksperimen dilaksanakan didalam laboratorium. Hasil menunjukkan tidak terdapat perbedaan pada metode penambahan perak nitrat ke dalam saringan keramik, sehingga pengembangan saringan keramik lebih mudah dan sangat memungkinkan menjadi alternatif untuk penyediaan air bersih dan layak konsumsi terutama pada keadaan darurat kebencanaanProblems of microbiologically contaminated water in Yogyakarta based on the results of routine monitoring by the City Health Office Yogyakarta in 2011 showed that the microbiological parameters are 596 (67%) of clean water sources (wells) population is not eligible in accordance Permenkes 492 / Menkes / Per / IV / 2010 , as well as in 2010 and 2009, respectively 68.8% and 63.2% of the samples examined, while for the examination of water piped (PDAM) in 2011, there are 8.9% of the sample were not eligible. It occurs in a densely populated residential area due to limited so that the distance between the infiltration wells latrine with a population less than the requirement. Use of Ceramic Filter as water treatment at household level has been widely studied and researched Research ceramic filters developed for the preparation of emergency response and densely populated area. This study used observational analytic design, the pretest-posttest approach to group design with quantitative analysis experiments were carried out in the laboratory. The results showed no difference in the method of adding silver nitrate into the ceramic filters, so that the development of ceramic filters easier and it is possible to be an alternative to the provision of clean and potable water, especially in an emergency disaster

Electromagnetic wave absorption and structural properties of wide-band absorber made of graphene-printed glass-fibre composite

Lightweight composites combining electromagnetic wave absorption and excellent mechanical properties are required in spacecraft and aircraft. A one- dimensional metamaterial absorber consisting of a stack of glass fibre/epoxy layers and graphene nanoplatelets/epoxy films was proposed and fabricated through a facile air-spraying based printing technology and a liquid resin infusion method. The production process allows an optimum dispersion of graphene nanoplatelets, promoting adhesion and mechanical integration of the glass fibre/epoxy layers with the graphene nanoplatelets/epoxy films. According to experimental results, the proposed wide-band absorber provides a reflection coefficient lower than −10 dB in the range 8.5–16.7 GHz and an improvement of flexural modulus of more than 15%, with a total thickness of ∼1 mm. Outstanding electromagnetic wave absorption and mechanical performance make the proposed absorber more competitive in aeronautical and aerospace applications

Time-Domain Finite Elements for Virtual Testing of Electromagnetic Compatibility

The paper presents a time-domain finite-element solver developed for simulations related to solving electromagnetic compatibility issues. The software is applied as a module integrated into a computational framework developed within a FP7 European project High Intensity Radiated Field – Synthetic Environment (HIRF SE) able to simulate a large class of problems. In the paper, the mathematical formulation is briefly presented, and special emphasis is put on the user point of view on the simulation tool-chain. The functionality is demonstrated on the computation of shielding effectiveness of two composite materials. Results are validated through experimental measurements and agreement is confirmed by automatic feature selective algorithms