Adsorpsi Ion Logam Kromium (Cr (Vi)) Menggunakan Karbon Aktif dari Bahan Baku Kulit Salak

Heavy metals are elements which are produced in industrial waste. This heavy metal waste causes pollution to the environment if the content of heavy metals contained therein exceeds the threshold. The toxic’s properties are extremely dangerous for humans if it accumulates in the human body. One of the heavy metals that are produced  is chromium. Several chemical and biological methods to remove heavy metals contained in the waste have been found. The adsorption method is one of the efficient and effective ways to treat heavy metal waste. In this study, activated carbon was prepared from salacca peel. Effects of pH, adsorbent dosage and Cr(VI) concentration on the adsorption of hexavalent chromium were investigated. The results were analyzed with Langmuir, Freundlich, Temkin, and Dubinin-Radushkevich adsorption isotherm models. And kinetic of the adsorption was performed based on pseudo first order, pseudo second order, and intraparticle diffusion equations. From the research, it is known that the optimum conditions for the Chromium(VI) adsorption occurs at pH 2. The adsorption capacity of salacca peel based activated carbons for the removal of hexavalent chromium was found to be 123 mg/g. And the best adsorption isotherm which can represent the adsorption equilibrium is Langmuir isotermal adsorption model. Moreover the data indicated that the adsorption kinetics follow the pseudo second orde

Adsorpsi Ion Logam Tembaga Menggunakan Karbon Aktif dari Bahan Baku Kulit Salak

Heavy metals contained inside water may carry negative impacts to humans and environment. The most effective treatment is adsorption using activated carbon which is obtained through chemical activation of snake fruit peel using KOH compound. The ratio of snake fruit peel to KOH (20%-w solution) used was 1:4. Snake fruit peel activated carbon with surface area of 2526  m2/g were obtained. The content of heavy metal ions (Cu2+) in the water were analyzed using spectrophotometer UV-Vis with NH3(p.a) solution which form a complex bound colored dark blue. Investigation was carried out by studying the influence of initial concentration (100, 150, 200, 250, and 300 ppm), pH (2,5; 3,5; 5), the amount of adsorbent (30, 60, 90 mg), dan temperature (25oC, 35 oC, dan 45 oC ) to obtain optimum condition with the highest %removal at initial concentration 100 ppm, pH 5, 90 mg adsorbent, and there's no significant differences by varying temperature. Adsorption isotherm studies indicated that Langmuir model fit better with maximum adsorption capacity of 687 mg/g and Langmuir constant for the variation of initial concentration and the amount of adsorbent were 0.0473 L/mg and 0.0296 L/mg, respectively. The kinetics of adsorption of Cu(II) followed pseudo second order

Proses Kerja Logistik di PT Harmoni Nusa Raya

Logistics is essential for all industries. Logistics is part of the supply chain of almost all companies that produce goods. Logistics aims to carry out the movement of goods from Inventory, Supplier, Warehouse, to distribution to customers or distributors. In this case, this activity cannot be separated from the existence of a transportation service provider company (3PL) in the distribution of raw goods and finished goods. With this 3PL company, the distribution of goods, especially exports and imports, can be easier. PT Harmoni Nusa Raya is a 3PL company that provides import-export logistics services and distribution of goods between cities

Kualitas Layanan Logistik sebagai Mediator terhadap Kemampuan Logistik dengan Kepuasan Pelanggan di PT Harmoni Nusa Raya

Untuk mampu bersaing dan memenangkan kompetisi, perusahaan logistik harus memberikan pelayanan yang terbaik bagi pelanggannya. Logistik merupakan suatu proses yang di dalamnya mengurus arus barang yang dikirim produsen ke konsumen yang membutuhkan strategi perusahaan untuk memberikan pelayanan terbaik kepada pelanggannya untuk meningkatkan kepuasan pelanggan. Tujuan dari penelitian ini yaitu untuk melakukan pengujian variabel Logistics Service Quality, Logistics Capabilities, dan Customer Satisfaction. Penelitian ini dilakukan di PT Harmoni Nusa Raya. Dalam pengujian, penulis menggunakan software SmartPLS. Penelitian ini menemukan bahwa Logistics Service Quality memediasi hubungan terhadap Logistics Capabilities dengan Customer Satisfaction, Dalam penelitian ini juga ditemukan adanya hubungan positif antara Logistics Capabilities dengan Logistics Service Quality, serta terdapat hubungan positif antara Logistics Service Quality dengan Customer Satisfaction

PENGARUH DOSIS DEMULSIFIER DAN TEMPERATUR TERHADAP PROSES PEMISAHAN EMULSI MINYAK/AIR

Minyak merupakan salah satu komponen yang umum dijumpai dalam limbah cair  berbagai proses industrial. Minyak tersebut seringkali dijumpai dalam bentuk emulsi dalam air, sehingga dibutuhkan metode pengolahan untuk memecah kestabilan emulsi agar minyak dapat dipisahkan. Pada penelitian ini, pemisahan dilakukan menggunakan demulsifier polialuminium klorida (PAC), yang juga merupakan salah satu jenis flokulan yang umum dijumpai dan digunakan dalam industri. Secara khusus, pengaruh dosis PAC (0 – 250 mg/L) dan temperatur (25 – 45°C) terhadap efektifitas demulsifikasi emulsi sintetis minyak/air menjadi fokus utama penelitian ini. Hasil riset menunjukkan bahwa dosis PAC, temperatur, dan interaksinya berpengaruh siginifikan terhadap proses demulsifikasi. Peningkatan dosis PAC hingga dosis 200 mg/L menghasilkan penurunan turbiditas dan pemisahan minyak, sementara penambahan dosis lebih lanjut tidak meyebabkan perubahan yang signifikan. Pada sisi lain, peningkatan temperatur membantu proses destabilisasi emulsi. Pada suhu yang lebih tinggi, frekuensi tumbukan droplet minyak akan meningkat, sedangkan ikatan hidrogen antara minyak dan surfaktan akan melemah. Hal tersebut akan mendorong terjadinya lebih banyak coalescence sehingga destabilisasi dan pemisahan minyak dari air. Penurunan turbiditas tertinggi (99,4%) dan pemisahan minyak terbanyak (97,45%) diperoleh pada dosis PAC 250 mg/L dan temperature 35°C. &nbsp

PENERAPAN MODEL PEMBELAJARAN BERBASIS MASALAH (PROBLEM BASED LEARNING ) DALAM MATA KULIAH MANAJEMEN LIMBAH B3

Perubahan metode pembelajaran yang sebelumnya berpusat pada pengajar (teacher-centered learning) menjadi berpusat pada siswa (student-centered learning), menuntut penggunaan berbagai model pembelajaran yang inovatif. Dalam penelitian ini dipaparkan penerapan model pembelajaran berbasis masalah (problem based learning; PBL) dalam mata kuliah Manajemen Limbah Bahan Beracun dan Berbahaya (B3) di Program Studi Teknik Kimia UNPAR pada semester genap 2016/2017, dengan tujuan mengamati  perubahan gaya belajar mahasiswa sebelum dan setelah pembelajaran dengan model PBL dengan menggunakan kuesioner Grasha. Selain itu mahasiswa diminta untuk mengisi kuesioner evaluasi pelaksanaan kegiatan pembelajaran. Teramati perubahan gaya belajar mahasiswa, yaitu pada menurunnya gaya belajar avoidant, kenaikan pada gaya belajar competitive dan collaborative. Sekalipun terlihat perubahan, hasil tersebut belum signifikan secara statistik. Hasil umpan balik dari mahasiswa peserta kuliah pun cukup positif, karena mahasiswa merasa lebih aktif, belajar bekerja dalam tim, dan berkomunikasi. Hasil-hasil positif yang ditunjukkan dalam penerapan model PBL pada mata kuliah ini membuka peluang untuk menerapkan model pembelajaran serupa pada berbagai mata kuliah lain

Potensi Polisakarida dari Limbah Buah-buahan sebagai Koagulan Alami dalam Pengolahan Air dan Limbah Cair: Review

Nowadays, various studies related to utilization of biobased materials as natural coagulants have been explored. Based on the source, natural coagulants can be classified as animal, vegetable, or microbial based. Furthermore, based on the active ingredients, it can be classified as protein, polyphenols, and polysaccharides. Polysaccharides are abundant natural ingredients and are often found in plants or animals. In this study, we focused on polysaccharides, especially those from fruit waste, such as seeds and fruit peels. It is known that around 25-30% of the total weight of fruit is generally wasted, even though it contains phytochemicals and various active ingredients that can be utilized, especially as a natural coagulant. This review will focus on the use of pectin and starch from fruit waste as natural coagulants for water- wastewater treatment. Generally, pectin is commonly found in the skin of fruits as part of the cell wall structure, while starch is found in fruit seeds as food reserves. To be used as a natural coagulant, pectin or starch need to be extracted first. In particular, starch needs to be modified either physically or chemically. The coagulation mechanism of pectin and starch usually follows the interparticle bridging mechanism. The use of pectin and starch from fruit waste needs to be explored and further investigated, to substitute the use of chemical coagulants.Keywords: coagulation; fruit waste; natural coagulant; polysaccharidesA B S T R A KDewasa ini berbagai studi terkait pemanfaatan bahan alam sebagai koagulan alami telah banyak dieksplorasi. Berdasarkan sumbernya, koagulan alami dapat digolongkan berbasis hewani, nabati, maupun mikrobial, sementara berdasarkan bahan aktifnya dapat digolongkan sebagai protein, polifenol, dan polisakarida. Polisakarida merupakan bahan alam yang berlimpah dan seringkali dijumpai pada tumbuh-tumbuhan dan hewan. Pada kajian ini difokuskan pada polisakarida terutama yang berasal dari limbah buah-buahan yang tidak termanfaatkan, seperti biji dan kulit buah. Diketahui sekitar 25-30% dari total berat buah pada umumnya terbuang, padahal memiliki kandungan fitokimia dan berbagai bahan aktif yang dapat dimanfaatkan, salah satunya sebagai koagulan alami. Pada tinjauan ini akan difokuskan pada pemanfaatan pektin dan pati dari limbah buah-buahan sebagai koagulan alami untuk pengolahan air dan limbah cair. Secara umum pektin umum dijumpai pada bagian kulit buah-buahan sebagai bagian dari struktur dinding sel, sementara pati umum dijumpai pada biji buah-buahan sebagai cadangan makanan. Untuk dapat dimanfaatkan sebagai koagulan alami, pektin ataupun pati perlu diekstrak terlebih dahulu, dan pati secara khusus perlu dimodifikasi baik secara fisika maupun kimia. Secara umum mekanisme koagulasi oleh pektin dan pati mengikuti mekanisme interparticle bridging. Pemanfaatan pektin dan pati dari limbah buah-buahan perlu dieksplorasi dan diteliti lebih lanjut, agar dapat mensubstitusi penggunaan koagulan kimia secara komersial.Kata kunci: koagulasi; koagulan alami; limbah buah-buahan; polisakarid

Utilization of Papaya Seeds as Natural Coagulant for Synthetic Textile Coloring Agent Wastewater Treatment

Textile wastewater contains a lot of pollutants which is hazardous if directly discharged. Coagulation and flocculation using inorganic salts were widely used to treat textile wastewater. However this method pose some drawbacks, such as high coagulant cost, large volume of sludge was produced, and potential health problems if the water is consumed. In this study we explore utilization of natural coagulant as an alternative to inorganic salts to treat textile wastewater. This study describes utilization of papaya seeds powder as a natural coagulant for synthetic textile wastewater of drimarene dark red (DDR) with initial concentration of 10 mg/L. The effect of coagulant dosage and pH to the %removal of colour in wastewater was studied using central composite design. The potential active functional groups in papaya seeds powder was characterized using Fourier Transform Infrared Spectroscopy (FTIR). It was found that papaya seeds powder contained –OH, -NH, C=O functional groups that indicate good potential as natural coagulant. The cubic model obtained was in good fit with experimental data, which was shown in R-squared value of 0.995. It was found that coagulant dosage, pH, and its interaction were significant to the removal of synthetic dye in wastewater. The decrease of pH gave higher %removal due to protonation of papaya seeds powder active coagulating agent resulting on better electrostatic interaction with dyes. The increase of dosage also gave increase in %removal until its optimum condition. After optimum condition, the %removal decreased due to colloid re-stabilization. The optimum condition was obtained at dosage of 0.57g/L and pH 1.97 with 84.77% of predicted colour removal and this result was in agreement with experimental response value

Adsorpsi Ion Logam Kromium (Cr (Vi)) Menggunakan Karbon Aktif dari Bahan Baku Kulit Salak

Heavy metals are elements which are produced in industrial waste. This heavy metal waste causes pollution to the environment if the content of heavy metals contained therein exceeds the threshold. The toxic’s properties are extremely dangerous for humans if it accumulates in the human body. One of the heavy metals that are produced  is chromium. Several chemical and biological methods to remove heavy metals contained in the waste have been found. The adsorption method is one of the efficient and effective ways to treat heavy metal waste. In this study, activated carbon was prepared from salacca peel. Effects of pH, adsorbent dosage and Cr(VI) concentration on the adsorption of hexavalent chromium were investigated. The results were analyzed with Langmuir, Freundlich, Temkin, and Dubinin-Radushkevich adsorption isotherm models. And kinetic of the adsorption was performed based on pseudo first order, pseudo second order, and intraparticle diffusion equations. From the research, it is known that the optimum conditions for the Chromium(VI) adsorption occurs at pH 2. The adsorption capacity of salacca peel based activated carbons for the removal of hexavalent chromium was found to be 123 mg/g. And the best adsorption isotherm which can represent the adsorption equilibrium is Langmuir isotermal adsorption model. Moreover the data indicated that the adsorption kinetics follow the pseudo second orde

Synthesis of Nano Silica Originated from Rice Husks using Sol Gel Method with Methanol as Solvent

Indonesia is an agricultural country that largely livelihood of the population in plants that produce carbohydrates such as rice, corn. Of the amount of rice produced there abundant agricultural waste. Agricultural wastes are utilized in this study is rice husk. In the rice husks are fairly large silica content is 16-18%. The purpose of this study for the synthesis nano silica from rice husk with the formation of silica phases and stages of formation nano silica. Silica formation stage was conducted using leaching and burning. While the formation stage nano silica conducted using sol gel + HCl 1M. Results are examined is the influence of solvent and aging time on the purity and characteristics nano silica. At this stage of the formation of silica, the leaching process using citric acid and burning at a temperature of 7500C for 5 hours resulted in the structure of amorphous silica and silica purity reached 93.08%. At this stage of formation nano silica with sol gel method using a variation of methanol and aging time. Variations solvent used is 1: 9, 1:16 and 1:19. While variations of aging time used is 1,3 and 6 days. Highest purity silica obtained by the method of sol gel variation of solvent 1: 9 and 1 day aging period at 75.45%. While the smallest nano-sized silica obtained by the sol gel method variation of solvent 1: 9 and aging time of 3 days with a size between 50-1500 n