ANALISIS RISIKO KESELAMATAN DAN KESEHATAN KERJA (K3) DENGAN METODE JOB SAFETY ANALYSIS (JSA) PADA PEMBANGUNAN SALURAN 5 TAHAP 3 DI PT. KRAKATAU SARANA PROPERTI

Kemajuan industri di Indonesia saat ini semakin maju dan kemajuan tersebut belum diimbangi dengan perhatian terhadap pemahaman dan penyelesaian keselamatan kerja secara tepat. Setiap kegiatan kerja pasti akan memiliki potensi bahaya yang dapat mengancam keselamatan dan kesehatan kerja. Menemukan dan mengidentifikasi potensi bahaya, menilai tingkat risiko dan mengevaluasi langkah-langkah yang telah dilakukan untuk mengendalikan risiko pada pembangunan saluran kerenceng 5 tahap 3 dengan menggunakan metode Job Safety Analysis (JSA). 7 sumber yang menimbulkan potensi bahaya yaitu pekerja yang tidak memakai alat pelindung diri (APD) pada saat pemecahan batu, jembatan yang tidak aman, menyusun batu, puing-puing batu yang berserakan, pekerja yang tidak menggunakan APD saat pengadukan semen dengan mesin, tanah yang tidak rata dan alat berat penggali yang telalu dekat dengan pekerja Pada potensi bahaya yang disebabkan oleh tanah yang tidak rata di pembangunan saluran, memiliki risiko bahaya adalah terpelosok dan melukai pekerja yang melewati. Maka dilakukan pengendalian eliminasi dengan cara meratakan tanah atau diberi palang dan tanda. Pada potensi bahaya yang disebabkan oleh alat berat penggali yang terlalu dekat dengan pekerja di pembangunan saluran kerenceng 5 tahap 3,memiliki risiko bahaya adalah pekerja yang melewatinya bisa terkena alat berat penggali. Maka dilakukan pengendalian teknologi dengan cara memberikan batas berupa palang dan tand

Pengaruh Komposisi Montmorillonite pada Pembuatan Polipropilen- Nanokomposit terhadap Kekuatan Tarik dan Kekerasannya

Polipropilen can be modified with bentonite (clay) that contain 50-80% montmorillonite. Montmorillonite has nano sized layers so that can be used as nanofiller on polipropilene-nanocomposite production. This research was done to find effect of montmorillonite composition on polipropilen-nanocomposite production to the mechanical properties. Mechanical tests in this research are tensile strength and hardness. Nanocomposite was produced through Melt Compounding method using injection molding equipment. This research used polipropilen (PP) and masterbatch that contain 0; 2,4, 3,6; and 5,4% montmorillonite composition. Result of the observation shows that nanofiller addition can increase mechanical properties of material. Optimum tensile strength was 32,88 MPa and was obtained when montmorillonite composition is 2,4%. Optimum hardness 72 mN was obtain when montmorillonite composition is 3,6%. Keywords: , montmorillonite, polipropilene-clay nanocomposite, mechanical tes

PEMBERDAYAAN PEREMPUAN DI DESA TEGAL BUNDER DALAM PRODUKSI HAND SANITIZER BERBASIS TANAMAN LOKAL CILEGON

PEMBERDAYAAN PEREMPUAN DI DESA TEGAL BUNDER DALAM PRODUKSI HAND SANITIZER BERBASIS TANAMAN LOKAL CILEGO

Pengaruh Cell Residence Time (Crt) Terhadap Kualitas Efluent Pada Pengolahan Limbah Cair Sintetik Tapioka

Sintetic Waste water of starch contained in average COD about 12300 mg/L and BOD 10.650 mg/L respectively. Waste water treatment of starch plant using biologycal treatment and settling commonly. Problem that frequently found in the biologycal treatment is dificulty in separation of biomass and incomplete contact of waste water with microorganisme and oxygen in the system. To overcome those problem is by applying system combination with aeration perforated plate bioreactor and membrane technology. Volume of bioreactor that used is 6 liters. Membran was polysulfon hollow fiber type. Hidraulic Residence Time (HRT) was 24 hours and Cell Residence Time (CRT) was 20, 40 and 60 days. Parameter process that measured is COD, BOD, DO and pH. The result of the research were efficiency COD removal for CRT 20, 40, 60 days can remove COD 92.8, 95.4 and 97.2%. respectively. BOD of effluent was 190-510 mg/L. DO of effluent was 0.5–0.7 mg/L. DO of permeat was 1.3– 1.9 mg/L and pH 6.6 – 6.9 mg/L. Keywords : Sintetic Waste water of starch, perforated plate bioreactor, membran

BIOPOLYMER-BASED FILM PREPARATION FOR POTENTIAL SMART FOOD PACKAGING MATERIAL APLLICATION

Public interest in colorimetric films for food freshness monitoring has increased recently. In addition to extending the shelf life of packaged food products, packaging materials are also required to provide current information about the freshness of the food while ensuring food quality and safety. The current work aims to prepare smart biodegradable films based on biopolymer-containing color indicators to monitor the quality of Decapterus spp. The pH-sensing colorimetric film was developed from a chitosan biopolymer modified using polyvinyl alcohol (PVA) and glycerol, as well as methyl red, as an indicator of fish freshness. The effect of using PVA and stirring conditions (temperature and time) on film production was evaluated on its physical appearance, water vapor permeability, and mechanical properties. The results show that the use of PVA can increase the transparency of chitosan films. Incorporating PVA into the film results in brighter and clearer colors compared to films without PVA. The temperature used in the preparation of the film solution has an influence on the mechanical properties and the water vapor permeability. The increasing stirring temperature leads to the enhancement of Young's modulus and the barrier properties against water vapor and moisture, still concurrently impacting a decrease in the film's yield strength and strain. Additionally, the film also exhibits responsiveness to pH during fish spoilage, with a color change that occurs from pink to yellowish. This confirms that the pH-responsive film resulting from this research has great potential to be applied as a real-time indicator of fish freshness during storage

SINTESA ASAM LAKTAT BERBAHAN BAKU TANDAN KOSONG KELAPA SAWIT MENGGUNAKAN TRICHODERMA RESEEI DAN LACTOBACILLUS ACIDIPILLUS

Tandan kosong kelapa sawit (TKKS) merupakan limbah pertanian dengan kadar selulosa yang tinggi, sehingga berpotensi untuk dikonversi menjadi berbagai macam produk. Salah satu senyawa kimia yang dapat dihasilkan dari selulosa TKKS adalah asam laktat. Asam laktat merupakan bahan baku utama dalam pembuatan polimer biodegradable berupa polilactic acid (PLA). Penelitian ini bertujuan untuk  mendapatkan konsentrasi mikroorganisme Lactobacillus acidophilus yang dapat menghasilkan asam laktat dengan konsentrasi yang tinggi. Tahapan penelitian meliputi pretreatment, hidrolisis dan fermentasi. Pretreatment TKKS menggunakan NaOH, Tahap  hidrolisis  selama 48 jam menggunakan Trichoderma reesei 5 % (w/w)  dan   tahap   fermentasi   selama  48 jam   menggunakan   Lactobacillus acidophilus dengan variasi 0.5; 1; 3; 5%. Analisa glukosa menggunakan spektrofotometri dan  asam laktat menggunakan High performance liquid chromatography (HPLC). Konsentrasi gula reduksi yang dihasilkan dari proses hidrolisis sebesar 16,6-17,9 g/L dan konsentrasi asam laktat tertinggi 0.568 g/L didapatkan dengan penambahan Lactobacillus acidophilus 3

PURIFIKASI POLY-Β HYDROXY BUTYRATE DARI GLUKOSA DALAM CUPRIAVIDUS NECATOR

Poly β-hydroxybutyrate (PHB) merupakan polimer yang paling umum dijumpai dari kelas Polyhydroxyalkanoate (PHA) dan merupakan jenis plastik dengan sifat 100% biodegradable. Tujuan penelitian ini adalah untuk mendapatkan pengaruh kondisi lysis dan ekstraksi dalam menghasilkan yield PHB di dalam Cupriavidus necator dengan substrat glukosa. Cupriavidus necator ditumbuhkan dalam medium Ramsay dan sumber karbon berupa glukosa menggunakan fermentor sistem batch. Hasil fermentasi dicuci dengan NaCl 0.625%, kemudian dilakukan sentrifugasi sehingga diperoleh pelet sel dan beningan (supernatant). Proses purifikasi dilakukan melalui dua tahap, yaitu lisis dan ekstraksi. Tahap lysis dilakukan menggunakan hidrogen peroksida (H2O2) dengan konsentrasi 5% dan 10% dan variasi temperatur 40 °C dan 80 °C. Ekstraksi PHB menggunakan kloroform (CHCl3) dengan temperatur operasi 30 °C dan 50 °C. Hasil penelitian menunjukkan bahwa yield PHB (grPHB/gr sel kering) tidak dipengaruhi secara signifikan oleh masing-masing variabel konsentrasi H2O2, temperatur lisis dan temperatur ekstraksi, tetapi dipengaruhi secara signifikan oleh interaksi ketiga variabel tersebut. Metode ANOVA dengan two-factor factorial design menunjukkan bahwa interaksi antara ketiga variabel didapat nilai Fo(9.482) yang lebih besar dari nilai F 0,05,1,8 (5.32). Yield PHB terbesar diperoleh pada konsentrasi H25%, temperatur lisis 40 °C dan temperatur ekstraksi 50 °C.</div

Acrylic Acid Neutralization for Enhancing the Production of Grafted Chitosan Superabsorbent Hydrogel

Acrylic acid is a hydrophilic monomer which becomes the most popular material used to synthesize superabsorbent polymer. In this recent study, acrylic acid was partially neutralized with KOH and mixed with chitosan to form a superabsorbent hydrogel poly (acrylic acid) – graft – chitosan by using of gamma ray irradiation technique. The aim of this study was to determine the optimum composition of KOH in acrylic acid partial neutralization process for enhancing the production of grafted polymer. The degree of neutralization was varied (0, 25, 50, 75, and 100)% and the effect on the superabsorbent characteristics were studied. Hydrogel products were characterized by Fourier Transform Infrared (FTIR) and Scanning Electron Microscopy (SEM). The gel content, swelling ratio, Equilibrium Degree of Swelling (EDS), and Thermal Analysis were also performed. The highest water swelling capacity was 715 (g water/g dry hydrogel), and the gel content was 91.23%, resulted from 75% of acrylic acid neutralization. The swelling capacity of the products was also tested in urea and NaCl solutions and reached 750 (g urea solution/g dry hydrogel) for urea and 378,33 (g NaCl solution/g dry hydrogel) for NaCl. The huge water absorption capacity indicated that the hydrogel from this research was a superabsorbent product which was suitable for hygiene products application. The degree of neutralization did not show a significant influence on the thermal resistance of the grafted hydrogel produced in this study

Synthesis and Characterization of Superabsorbent Sodium Alginate-G-Poly (Potassium Acrylate) Hydrogels Prepared By Using Gamma Irradiation

The aim of this research was to use gamma rays as sources for the preparation of superabsorbent hydrogels through radiation induced copolymerization. A series of superabsorbent hydrogels were prepared from aqueous solution containing partially neutralized acrylic acid (15%) with different sodium alginate (NaAlg) concentrations (0.5% to 1.5%) by ionizing gamma irradiation (10 kGy to 40 kGy) at room temperature. The effect of NaAlg concentration and irradiation doses on the water absorption behavior of the obtained hydrogels was investigated. The structural changes of hydrogels were characterized using Fourier Transform Infrared (FTIR) whereas the morphologies of hydrogels were examined using Scanning Electron Microscope (SEM). The results showed the swelling of hydrogel in water and NaCl solution increases with increasing NaAlg concentration and decreases with increasing irradiation dose up to 40 kGy. The extend of gel fraction increases as a function of NaAlg concentration. The results of FTIR analysis revealed that acrylic acid and sodium alginate had been successfully grafted, while SEM examination showed that the hydrogels demonstrated large numbers of pores.   

Influence of chitosan addition on the properties and characteristics of acrylic acid-chitosan based superabsorbent prepared through gamma irradiation technique and its application for urea loading

Superabsorbent can be used as a carrier for urea-fertilizer which can release urea slowly and can be used as a dry soil moisturizer. The main goal of the current study was to investigate the influence of adding chitosan grafted onto acrylic acid as a superabsorbent base material on the properties and characteristics of the resulting superabsorbents. The method used to prepare the superabsorbent was the gamma irradiation technique. Acrylic acid was neutralized by adding KOH, and then chitosan was added. The mixture was put in a plastic container, followed by irradiation with gamma rays. The formed superabsorbent was washed and dried in an oven, then the dry superabsorbent was analyzed for its properties and characteristics. The results showed that superabsorbent properties such as swelling ratio (from 49.38 g/g to 49.38 g/g), water retention (0.43%-0.89% after 7 days), and urea loading (86.75% to 96.4%) were affected by the amount of chitosan added. However, adding too much chitosan can reduce the superabsorbent properties. The characterization of the superabsorbent revealed a smooth surface with a porous structure, and FTIR analysis showed that chitosan was grafted onto acrylic acid.   </div