Equilibrium Journal of Chemical Engineering
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Sintesis dan Analisis Struktur Prekursor NMC811 dari Mix Hydroxide Precipitate (MHP) dengan Presipitan Asam Oksalat
Get PDFABSTRAK. Studi mengenai struktur kristal suatu material sangat penting dalam mengetahui baik tidaknya material, terutama untuk aplikasi teknologi penyimpanan energi listrik seperti baterai ion litium. Semakin murni dan baik suatu struktur kristal material, maka semakin baik efisiensinya dalam menjadi bahan baku material katoda baterai. Tujuan dari penelitian ini adalah sintesis dan analisis karakteristik struktur kristal prekursor NMC811 oksalat (Ni0,8Mn0,1Co0,1C2O4) dari senyawa Mixed hydroxide precipitate atau MHP dengan presipitan asam oksalat. Sintesis prekursor NMC811 dilakukan dengan mereaksikan MHP (Ni 51,43% wt) dengan asam asetat agar diperoleh larutan nikel asetat. Sejumlah garam kobalt dan mangan ditambahkan kedalam larutan sehingga komposisi nikel:kobalt:mangan senilai 8:1:1. Endapan prekursor diperoleh dengan penambahan presipitan larutan asam oksalat. Endapan prekursor yang berhasil diisolasi dianalisis dengan X-ray diffractometer (XRD) untuk evaluasi struktur kristalnya. Berdasarkan analisis XRD MHP memiliki puncak difraksi yang kurang tajam dengan lebar pita yang relative besar sehingga menandakan bahwa MHP memiliki sifat kristal yang buruk. Sementara itu, Prekursor NMC811 oksalat memiliki puncak difraksi yang tajam. Hal ini membuktikan prekursor memiliki sifat kristal yang baik dengan kemurnian yang tinggi. Oleh karena itu, Prekursor NMC811 oksalat dengan bahan baku MHP dapat digunakan untuk bahan baku material katoda baterai ion litium tipe NMC811. ABSTRACT. The study of the crystal structure of a material is very important in knowing whether or not the material is good, especially for the application of electrical energy storage technology such as lithium ion batteries. The purer and better the crystal structure of a material, the better its efficiency in becoming a battery cathode raw material. The purpose of this study was to synthesize and analyze the characteristics of the crystal structure of the precursor NMC811 oxalate (Ni0,8Mn0,1Co0,1C2O4) from Mixed hydroxide precipitate or MHP with oxalic acid as a precipitate. NMC811 precursor was synthesized by reacting MHP (Ni 51.43% wt) with acetic acid to obtain a nickel acetate solution. A number of cobalt and manganese salts are added to the solution so that the nickel:cobalt:manganese composition is 8:1:1. The precursor precipitate was obtained by adding oxalic acid solution as a precipitate. The isolated precursor precipitate was analyzed by X-ray diffractometer (XRD) to evaluate its crystal structure. Based on XRD analysis, MHP has a diffraction peak that is less sharp with a relatively large bandwidth, indicating that MHP has poor crystalline properties. Meanwhile, NMC811 oxalate precursor has a sharp diffraction peak. This proves the precursor has good crystalline properties with high purity. Therefore, the NMC811 oxalate precursor with MHP raw material can be used as the cathode material for the lithium ion battery type NMC811
The Effects of Different Nickel–Ruthenium on SiO2 Catalyst Synthesis Methods toward Catalytic Activity of Methane Dry Reforming
Get PDFThe presence of greenhouse gases in the atmosphere has triggered global warming and climate change. An effective approach to overcome these issues is to convert greenhouse gases into syngas. In this study, Ni-Ru/SiO2 catalyst was used to catalyze the dry reforming process of methane (CH4) and carbon dioxide (CO2) into syngas. The catalyst was prepared using different synthesis protocols: sol gel-coprecipitation and impregnation methods. Characterization using Brunauer Emmett Teller analysis showed that the catalyst prepared using both methods exhibited comparable pore diameters and high surface areas. The X-ray diffractometer analysis also indicated the presence of different NiO, RuO2, and SiO2 phases. Furthermore, the activity of the catalyst was investigated using a fixed bed reactor. Based on the results, the optimum catalytic activity was obtained from the catalyst prepared via the sol gel-coprecipitation method, with an average CH4 and CO2 conversions of 37% and 50%, respectively. In addition, our catalyst also showed a 114% higher CH4 conversion with an enhanced H2/CO ratio compared to identical catalysts from other studies
Potensi Pasar Rakyat di Surabaya Barat sebagai Contoh Pasar Bebas Kantong Plastik
Get PDFABSTRAK. Surabaya Barat memiliki pasar rakyat yaitu Pasar Lakarsantri, Asemrowo, Balongsari, Manukan Kulon, Banjarsugihan, Simo, dan Simo Mulyo yang berpotensi menyumbangkan timbulan sampah plastik berupa kantong plastik. Disisi lain, timbulan sampah plastik di pasar Kota Surabaya telah mencapai 20 ton/hari. Himbauan terkait pembatasan penggunaan kantong plastik sebenarnya telah diatur dalam Peraturan Daerah Kota Surabaya Nomor 1 tahun 2019 namun belum diketahui oleh setiap pengelola, pembeli, dan pedagang di pasar rakyat Kota Surabaya sehingga perlu Program Pasar Rakyat Bebas Kantong Plastik. Namun, aspek bangunan dan keramaian pasar juga perlu dipertimbangkan. Oleh karena itu, penelitian ini bertujuan untuk mengetahui aspek bangunan dan keramaian pasar rakyat di area Surabaya Barat dalam mendukung Program Pasar Rakyat Bebas Kantong Plastik. Metode yang digunakan dalam penelitian ini yaitu metode obeservasi lapangan kemudian dianalisis menggunakan deskriptif kualitatif. Hasil penelitian ini menunjukkan bahwa pasar rakyat di area Surabaya Barat dengan dominasi bangunan permanen serta tingkat keramaian pasar cukup ramai sampai ramai ditetapkan sebagai pasar rakyat yang berpotensi mendukung Program Pasar Rakyat Bebas Kantong Plastik karena mampu melindungi barang dagangan pedagang dan belanjaan pembeli ketika waktu hujan tiba, menciptakan kenyamanan terhadap pembeli pasar untuk berbelanja, serta memudahkan pengawasan dan penertiban. Pasar rakyat tersebut meliputi Pasar Balongsari, Banjarsugihan, dan Simo Mulyo. ABSTRACT. West Surabaya has folk markets, namely Lakarsantri, Asemrowo, Balongsari, Manukan Kulon, Banjarsugihan, Simo, and Simo Mulyo which have potential to contribute generation of plastic waste in the form of plastic bags. Plastic waste in the Surabaya market has reached 20 tons/day. The call for restrictions on the use of plastic bags has actually been regulated in Peraturan Daerah Kota Surabaya Nomor 1 Tahun 2019 but has not been known by managers, buyers, and traders so that a Plastic Bag Free Traditional Market is needed. However, the market buildings and crowds also need to be considered. This study aims to determine the building and the crowds of the folk markets in the West Surabaya area in supporting the program. The Method used is field observation and qualitative descriptive analysis. The results indicate the dominance of permanent buildings and the level of market crowds from being quite busy to crowded is designated as a folk market that has the potential to support the program because it can protect the merchandise of traders and buyers’ purchases when it rains, create convenience for market buyers to shop, as well as facilitate supervision and control. Folk markets include Balongsari, Banjarsugihan, and Simo Mulyo
Brewery Effluent Treatment with Conventional and Natural Coagulants
Get PDFABSTRACT. In water scarce countries such as Eritrea, maintaining brewery industry remain ever challenging task. Currently, Asmara breweries is the only beer producing factory consuming 8.46 L of water per every L of beer produced which is notably higher than Brewer’s Association (BA) benchmark and consequently generates 7.53 L of wastewater/L of beer. Bottle cleaning and brewery activities ascertain ample effluent bases. Wastewater from bottle cleaning (BCWW), brewery (BWW) and mixed (MWW) have attributed a wide spectrum of 3500-160000 mg/L of COD and 327-26667 mg/L of BOD5, which are significantly overtops other reported brewery effluents. Physicochemical treatments including coagulation with conventional (alum) and natural (MO seed) flocculants have tested to remove higher COD and BOD5 concentrations of brewery effluents. Optimal coagulant dosage determined by accounting turbidity as a key performance indicator. Alum treatment of BCWW and MO seed flocculation of MWW have resulted in lower turbidity levels of 0.49 and 6.17 NTU at 60 mg/L of dosages respectively. The optimal quantities of 92.2 % and 86.6% (by weight) of water recovered from alum treatment of BCWW and MO seed coagulation of MWW respectively. Higher sludge volumes recorded as a major disadvantage in alum coagulation whereas natural coagulant, MO seed manifested competitive results in removal of COD, BOD5, Chlorine, Nitrogen, Sulphate, Sodium, TDS and TSS along with PH stabilization. In addition, 97.2% of influent turbidity removed through MO seed coagulation treatment, an equipollent to alum despite of four fold increment in potassium levels.Keywords: Brewery Wastewater Coagulation Alum Moringa Oliefera Effluent Treatmen
Analisis Morfologi Prekursor NMC811 dari Mix Hydroxide Precipitate (MHP) dengan Presipitan Asam Oksalat
Get PDFABSTRAK. Morfologi material merupakan salah satu aspek yang berpengaruh pada kualitas material katoda baterai Li-ion atau LIBs, salah satunya material katoda LiNi0,8Mn0,1Co0,1O2 atau NMC811. Semakin baik distribusi ukuran dan butiran partikel, maka semakin baik pula kualitas dari produk akhir NMC811. Penelitian ini bertujuan untuk sintesis dan analisis prekursor NMC811 (Ni0,8Mn0,1Co0,1C2O4) dengan mixed hydroxide precipitate atau MHP sebagai sumber Ni. Pada penelitian ini, prekursor NMC811 oksalat diperoleh dengan melarutkan MHP, CoSO4 dan MnSO4 pada larutan asam asetat. Larutan yang terbentuk dipresipitasi dengan asam oksalat sehingga membentuk endapan prekursor NMC811 oksalat. Instrumen pengujian SEM-EDX digunakan dalam mengevaluasi karakteristik morfologi sampel. Studi komparasi morfologi prekursor NMC811 dengan MHP juga dilakukan. prekursor Berdasarkan analisis komposisional menggunakan EDX, komposisi atom C, O, Mn, Co dan Ni secara berturut-turut 15,21±0.55%; 57,64±1.37%; 4,47±0.59%; 4,20±0.74%; dan18,48±1.71%. Sementara itu, analisis menggunakan SEM menunjukkan bahwa prekursor NMC811 memiliki bentuk dan ukuran partikel yang cenderung seragam dan lebih kompak dibandingkan MHP yang memiliki bentuk dan ukuran yang lebih bervariasi. Sintesis awal NMC811 dengan presipitan asam oksalat dapat meningkatkan keseragaman morfologi yang baik, sehingga nantinya dapat dihasilkan produk akhir NMC811 yang baik pula. ABSTRACT. Material morphology is one aspect that affects the quality of the cathode material for Li-ion batteries or LIBs, one of which is LiNi0,8Mn0,1Co0,1O2 or NMC811 cathode materials. The better the particle size and grain distribution, the better the quality of the final NMC811 product. This study aimed to synthesize and analyze the precursor of NMC811 (Ni0,8Mn0,1Co0,1C2O4) with mixed hydroxide precipitate or MHP as the source of Ni. In this study, NMC811 oxalate precursor was obtained by dissolving MHP, CoSO4 and MnSO4 in acetic acid or lactic acid solution. The solution formed was precipitated with oxalic acid to form a precursor precipitate of NMC811 oxalate. The SEM-EDX test instrument was used to evaluate the morphological characteristics of the samples. A comparative study of the morphology of the NMC811 precursor with MHP was also carried out. precursors Based on the compositional analysis using EDX, the atomic compositions of C, O, Mn, Co and Ni were 15.21±0.55%, respectively; 57.64±1.37%; 4.47±0.59%; 4.20±0.74%; and 18.48±1.71%. Meanwhile, analysis using SEM showed that the NMC811 precursor had a particle shape and size that tended to be uniform and more compact than MHP which had a more varied shape and size. The initial synthesis of NMC811 with oxalic acid precipitant can improve the good morphological uniformity, so that later, a good final product of NMC811 can be produced
Proses Purifikasi untuk Penyisihan Kandungan Hidrogen Sulfida dan Karbon Dioksida di Dalam Biogas Menggunakan Mono Etanol Amin (MEA)
Get PDFABSTRAK. Biogas merupakan salah satu sumber energi terbarukan, yang mampu dihasilkan dari limbah organik seperti limbah cair sawit (POME), melalui proses fermentasi anaerobik. Untuk menghindari terjadinya korosi pada peralatan, biogas hasil fermentasi diperlukan proses purifikasi untuk menyisihkan kandungan hidrogen sulfida (H2S). Tujuan dari penelitian ini yaitu untuk menentukan pengaruh penggunaan monoethanolamine (MEA) pada purifikasi biogas, menentukan kondisi terbaik dari variabel penelitian (konsentrasi MEA 30%, 25%, 20%, 15% 10%, 5% v/v) yang memiliki kandungan H2S terendah, dan menentukan efisiensi proses purifikasi biogas. Purifikasi biogas dilakukan menggunakan bubble column absorber secara semi-batch, dimana biogas mentah dialirkan ke kolom yang berisi absorber MEA sebanyak 0,678 L. Biogas keluaran kolom dianalisa kandungannya menggunakan alat pengukur kandungan biogas (Biogas 5000 ©). Hasil penelitian menunjukkan bahwa penggunaan MEA sebagai absorben mampu menurunkan kandungan gas H2S dan menaikkan kandungan gas CH4 di dalam biogas hasil purifikasi, serta semakin tinggi variasi konsentrasi MEA yang digunakan, maka semakin rendah kandungan H2S biogas dan semakin lama waktu absorbsi yang diperlukan untuk absorben mencapai titik jenuh. Kondisi terbaik absorbsi tercapai pada penggunaan variasi konsentrasi MEA 30% v/v, dengan kandungan H2S pada biogas hasil purifikasi 0 ppm, dan efisiensi penyisihan H2S sebesar 100%. ABSTRACT. Biogas is a renewable energy source, which can be produced from organic waste such as palm oil mill effluent (POME), through an anaerobic fermentation process. Biogas requires a purification process to remove the content of hydrogen sulfide (H2S) and carbon dioxide (CO2). The purpose of this study is to review the effect of the biogas purification process of chemical absorption of H2S and CO2 gases in raw biogas by monoethanolamine (MEA) absorbent. Biogas purification was carried out using a bubble column absorber in a semi-batch, where raw biogas was flowed into a column containing a MEA absorber of 0.678 L. The biogas content from the column was analyzed using a biogas content measuring device (Biogas 5000 ©). The result showed that removing the use of MEA as an absorbent can reduce the content of hydrogen sulfide (H2S) and carbon dioxide (CO2) and improve the content of methane in biogas. Increasingly high variation concentration MEA, then the lower content of hydrogen sulfide (H2S) and more time long to reach the point saturated absorbability
Karakterisasi Kelarutan Silika dari Fly Ash Kelapa Sawit dalam Larutan Basa Kuat (NaOH) dan Asam Lemah (C6H8O7)
No full textABSTRAK. Pertumbuhan industri pabrik kelapa sawit masih cukup potensial di Indonesia. Kajian produk samping hasil produksi pabrik kelapa sawit ini masih belum diolah dengan optimal. Pemanfaatan fly ash sebagai salah satu produk samping masih sangat perlu dikembangkan. Silika merupakan komposisi penyusun fly ash pabrik kelapa sawit yang sangat diminati saat ini karena memiliki potensi aplikasi dalam berbagai tujuan seperti pengolahan limbah, material semikonduktor, dan bahan aditif pertanian. Penelitian pengolahan silika dari abu hasil proses pembakaran tidak terlepas dari metode ektraksi yang sangat bergantung dari karakteristik kelarutan silika terhadap pelarutnya. Penelitian ini bertujuan untuk memberikan informasi karakteritik kelarutan silika yang berasal dari fly ash pabrik kelapa sawit dalam larutan berupa basa kuat (NaOH) dan asam lemah (C6H8O7). Aktivitas kelarutan silika dalam pelarut asam dan basa dilakukan dengan memvariasikan konsentrasi pelarut yaitu 1 M, 2 M, dan 3 M. Proses pelarutan silika dilakukan pada temperatur 60oC dalam waktu 60 menit. Karaketrisasi fly ash dilakukan dengan menggunakan instrumen XRD, XRF, dan SEM yang menunjukkan bahwa senyawa penyusun utama fly ash adalah CaO 68,894% dan SiO2 19,189 % yang terkandung dalam mineral kalsit, portlandite, dan kuarsa dengan morfologi yang heterogen serta ukuran partikel berkisar 200 μm – 300 μm. Hasil pelarutan menunjukkan bahwa kelarutan silika tertinggi diperoleh dalam pelarut asam sitrat 2 M yaitu sebesar 26,35 %.Kata kunci: Kelarutan, Silika, Asam Lemah, Basa Kuat, NaOH, (C6H8O7) ABSTRACT. The growth of the palm oil mill industry still has quite potential in Indonesia, but the study of by-products produced by palm oil mills is immobile and not managed optimally. The use of fly ash as one of the by-products urgently necessities to be developed. Silica is a constituent composition of palm oil fly ash that is in great demand today because it has potential applications in various purposes such as sewage treatment, semiconductor materials, and agricultural additives. Research on silica processing from ash from the combustion process is inseparable from the extraction method which is highly dependent on the characteristics of silica solubility to the solvent. This study aims to provide information on the characteristics of silica solubility derived from palm oil mill fly ash in a solution in the form of strong bases (NaOH) and weak acids (C6H8O7). The solubility activity of silica in acidic and alkaline solvents is carried out by varying the solvent concentration of 1 M, 2 M, and 3 M. Silica dissolution process is carried out at a temperature of 60oC within 60 minutes. Fly ash characterization was carried out using XRD, XRF, and SEM instruments which showed that the main constituent compounds of fly ash were CaO 68.894% and SiO2 19.189% contained in calcite, portlandite, and quartz minerals with heterogeneous morphology with particle size between 200 μm – 300 μm. The dissolution results showed that the highest silica solubility was obtained in a 2 M citric acid solvent, which was 26.35%.Keywords: Solubility, Silica, Weak Acid, Strong Base, NaOH, (C6H8O7
Isolasi Gelatin dari Limbah Tulang Ikan Nila (Oreochromis Niloticus): Pengaruh Suhu dan Waktu Ekstraksi
Get PDFAbstrak. Gelatin adalah sejenis derivate protein dari serat kolagen yang dapat diekstraksi dari tulang. Penelitian ini bertujuan untuk mengetahui mengetahui pengaruh suhu dan waktu ekstraksi terhadap hasil ekstraksi isolasi gelatin dari tulang ikan nila. Tahapan isolasi gelatin meliputi degreasing menggunakan air, demineralisasi dengan rasio bubuk tulang ikan nila dan aquades 1:10 (b/v), serta ekstraksi. Ekstraksi menggunakan pelarut aquades dengan rasio ossein dan aquades 1:10 (b/v). Suhu ekstraksi divariasi 50oC, 60oC, dan 85oC, dengan lama waktu 1 jam, 3 jam, dan 5 jam. Gelatin terbanyak diperoleh pada suhu 60oC dengan waktu 1 jam sebesar 0,86 gram (rendemen 9,55%). Uji terhadap gelatin diperoleh viskositas gelatin 1,442-2,844 cp, pH gelatin 5,2-6,8, dan kadar abu sebesar 2,143-2,778%. Uji FTIR menunjukkan bahwa produk mengandung gugus fungsi amina dan karbonil pada panjang gelombang 1206,53 cm-1, 1270,18 cm-1, dan 1286,58 cm-1. Gelatin yang diperoleh memenuhi standar mutu gelatin komersial.Abstract. Gelatin is a type of protein derivate from collagen fibers that can be extracted from bone. This study aims to determine the effects of temperature and extraction time on the extract of isolated gelatin from tilapia fish bones. Gelatin isolation stages include degreasing using water, demineralization with a ratio of 1:10 (w/v) tilapia bone powder and distilled water, and extraction. The extraction used distilled water with a ratio of ossein and distilled water 1:10 (w/v). The extraction temperature was varied at 50oC, 60oC, and 85oC, for 1 hour, 3 hours, and 5 hours. The highest yield of gelatin was obtained at a temperature of 60oC in 1 hour, i.e. 0.86 g (yield of 9.55%). The test on gelatin obtained the gelatin viscosity from 1,442-2,844 cP, gelatin pH 5,2-6,8, and ash content of 2,143-2,778%. The FTIR test showed that the product contained amine and carbonyl functional groups at the wavelengths of 1206.53 cm-1, 1270.18 cm-1, and 1286.58 cm-1. The gelatin obtained meets the commercial gelatin quality standards
Biosorption of Chromium from Textile Wastewater Using Mimosa pudica Tannin Gel
Get PDFAbstract. The heavy metal content is very dangerous because it can pollute the environment. One of the heavy metals waste commonly found in the textile industry is chromium (Cr). Mimosa pudica is a weed plant and its availability is very abundant. However, it also contains tannin which can be developed into tannin gel biosorbent to adsorption heavy metal content in the wastewater. The purpose of this research is to study Mimosa pudica tannin as a Cr biosorbent from textile wastewater. There are two steps to synthesis tannin gel biosorbent. They are the tannin extraction and the condensation polymerization process. Tannin is easily soluble in water so the condensation polymerization process is needed to make it insoluble in water. The extraction of Mimosa pudica tannin was done using water solvent. The condensation polymerization process was done by the reaction of tannin extract and formaldehyde. The Cr content of textile industry wastewater in the Pasar Kliwon, Surakarta was 4 ppm. The results of the biosorption of Cr heavy metal using Mimosa pudica tannin gel showed that the remaining Cr heavy metal was 0.7098 ppm. It was already below the threshold which was 1 ppm. Keywords: biosorption, condensation polymerization, extraction, Mimosa pudica, tannin ge
Adsorbsi Zat Warna Alami Buah Mangrove Jenis rhizophora stylosa dan Kulit Kayu Tingi ke dalam Kain dengan Pengunci Tunjung dan Tawas
Get PDFAbstrak. Industri tekstil di Indonesia berkembang pesat, hal ini ditegaskan oleh data Badan Pusat Statistik (BPS) yang menunjukkan produksi industri sandang mengalami pertumbuhan yang signifikan sebesar 15,29 persen pada tahun 2019. Penggunaan pewarna tekstil akan menimbulkan limbah. masalah di lingkungan. Sehingga diperlukan pewarna alami sebagai alternatif yang lebih aman dan ramah lingkungan. Tujuan dari penelitian ini adalah untuk memperoleh analisis data dan menentukan nilai kesetimbangan adsorpsi larutan pewarna alami kulit batang pohon bakau Rhizophora stylosa dan tingi dengan variasi jumlah pencelupan pada kain primisima dengan membandingkannya dengan persamaan Langmuir dan Freundlich serta mengetahui peran tunjung dan tawas dalam proses pengikatan zat warna menjadi kain. Penelitian ini menggunakan metode ekstraksi padat-cair kemudian diuji dengan spektrofotometri untuk mendapatkan data konsentrasi awal. Selanjutnya, tuangkan zat warna yang telah diuji kandungan taninnya ke dalam gelas ukur dan masukkan kain sebagai media perpindahan massa tanin dari cair ke padat. Sampel diambil untuk setiap pencelupan dan diuji kandungan tanin secara spektrofotometri dan diperoleh nilai Ca. pengujian pola isoterm. Uji adsorpsi proses penyerapan tanin pada zat warna alam oleh kain dilakukan dengan menghitung menggunakan persamaan Langmuir dan Freundlich. Selanjutnya kain yang telah diwarnai difiksasi dengan tunjung dan tawas. Penentuan kapasitas adsorpsi kain yang paling sesuai terhadap pewarna alam Rhizopora stylosa dan kulit kayu tingi adalah dengan menggunakan persamaan adsorpsi Freundlich dibandingkan dengan persamaan Langmuir. Hal ini dibuktikan dengan nilai error persamaan Freundlich lebih kecil dari pada persamaan Langmuir dengan menunjukkan nilai R2 yang mendekati angka 1. Nilai konstanta persamaan Langmuir kulit tingi selama tiga kali pencelupan diperoleh nilai b sebesar 0,2338 mg/gr dan nilai k adalah 0,00517 L/gr. Untuk lima kali pencelupan diperoleh nilai b sebesar 0,10817 mg/gr dan nilai k sebesar 0,00421 L/gr. Untuk tujuh kali pencelupan diperoleh nilai b sebesar 0,0670 mg/gr dan nilai k sebesar 0,003899 L/gr. Sedangkan pada persamaan Freundlich untuk kulit kayu tingi untuk tiga kali pencelupan diperoleh nilai n sebesar 0,4312 mg/g dan nilai k sebesar 0,36374 x 103 L/gr. Untuk lima kali pencelupan nilai n sebesar 0,30114 mg/g dan nilai k sebesar 0,99586 x 105 L/g. Untuk tujuh kali pencelupan nilai n sebesar 0.2424 mg/g dan nilai k sebesar 0.9354 x 107 L/g. Nilai konstanta persamaan Langmuir Rhizopora stylosa untuk tiga kali pencelupan, nilai b 0,15635 mg/gr dan nilai k 0,005224 L/gr. Untuk lima kali pencelupan diperoleh nilai b sebesar 0,08141 mg/gr dan nilai k sebesar 0,004415 L/gr. Untuk ketujuh pencelupan diperoleh nilai b sebesar 0,04909 mg/gr dan nilai k sebesar 0,00408 L/gr. Sedangkan pada persamaan Freundlich untuk Rhizopora stylosa untuk tiga kali pencelupan diperoleh nilai n sebesar 0,3862 mg/g dan nilai k sebesar 0,1090 x 104 L/g. Untuk lima kali pencelupan nilai n sebesar 0,2733 mg/g dan nilai k sebesar 0,4355 x 106 L/g. Untuk tujuh kali pencelupan diperoleh nilai n sebesar 0,2126 mg/g dan nilai k sebesar 0,1545 x 109 L/g. Dapat disimpulkan bahwa semakin banyak pewarnaan maka daya serap kain terhadap tanin semakin kecil. Perubahan warna fiksasi kain pada pencelupan ekstrak Rhizopora stylosa dengan tunjung adalah dari coklat menjadi coklat keabu-abuan, sedangkan dengan tawas dari coklat menjadi coklat tua. Perubahan warna fiksasi kain pada pencelupan ekstrak kulit tingi dengan tawas adalah dari coklat menjadi hitam, sedangkan dengan tawas dari coklat menjadi coklat tua. Abstract. The textile industry in Indonesia is growing rapidly, this is confirmed by data from the Badan Pusat Statistik (BPS) which shows that the production of the clothing industry has experienced a significant growth of 15.29 percent in 2019. The use of textile dyes will cause waste problems in the environment. So we need natural dyes as a safer and environmentally friendly alternative. The purpose of this study was to obtain data analysis and to determine the adsorption equilibrium value of the natural dye solution of mangrove Rhizophora stylosa and tingi bark with variations in the amount of dyeing in primisima cloth by comparing it with the Langmuir and Freundlich equations and knowing the role of tunjung and alum in the process of fixing dyes into cloth. This study used a solid-liquid extraction method and then tested by spectrophotometry to obtain initial concentration data. Next, pour the dye that has been tested for its tannin content into a measuring cup and insert the cloth as a medium for mass transfer of tannins from liquid to solid. Samples were taken for each dyeing and tested for tannin content by spectrophotometry and the Ca value was obtained. Isotherm pattern testing. The adsorption test for the absorption process of tannins in natural dyes by cloth was carried out by calculating using the Langmuir and Freundlich equation. Furthermore, the cloth that has been dyed is fixed by tunjung and alum.The most suitable determination of the adsorption capacity of the cloth against natural dyes Rhizopora stylosa and tingi bark is by using the Freundlich adsorption equation compared to the Langmuir equation. This is evidenced by the error value of the Freundlich equation is smaller than the Langmuir equation by showing the value of R2 which is close to number 1. The constant value of the Langmuir equation tingi bark for three times of dyeing obtained the b value is 0.2338 mg/gr and the k value is 0.00517 L/gr. For five of dyeing, the b value is 0.10817 mg/gr and the k value is 0.00421 L/gr. For the seven times of dyeing, the b value is 0.0670 mg/gr and the k value is 0.003899 L/gr. Whereas in the Freundlich equation for tingi bark for three times of dyeing, the n value is 0.4312 mg/g and the k value is 0.36374 x 103 L/gr. For five of dyeing, the n value is 0.30114 mg/g and the k value is 0.99586 x 105 L/g. For seven of dyeing, the n value is 0.2424 mg/g and the k value is 0.9354 x 107 L/g. The constant value of the Langmuir Rhizopora stylosa equation for three times of dyeing, the b value is 0.15635 mg / gr and the k value is 0.005224 L/gr. For five of dyeing, the b value is 0.08141 mg/gr and the k value is 0.004415 L/gr. For the seven of dyeing, the b value is 0.04909 mg/gr and the k value is 0.00408 L/gr. Whereas in the Freundlich equation for Rhizopora stylosa for three times of dyeing, the n value is 0.3862 mg/g and the k value is 0.1090 x 104 L/g. For five of dyeing, the n value is 0.2733 mg/g and the k value is 0.4355 x 106 L/g. For seven of dyeing, the n value is 0.2126 mg/g and the k value is 0.1545 x 109 L/g. It can be concluded that the more dyeing, the less the absorbency of the cloth on tannins. The color change of fixation the cloth in the dyeing of Rhizopora stylosa extract with tunjung is from brown to grayish brown, while with alum from brown to dark brown. The color change of fixation the cloth in the dyeing of tingi bark extract with alum is from brown to black, while with alum from brown to dark brown