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"This paper discusses the preparation, characterization, and the evaluation of adsorption properties of resin poly-tetra-p-allylcalix[4]arene tetra acetic acid from the p-t-butylphenol. The synthesized resins were applied as an adsorbent for Cr(III) and Pb(II) metal ions. The adsorption was conducted in a batch system by investigating the effects of acidity (pH), contact time and initial concentration of a heavy metal solution. The adsorption of Cr(III) and Pb(II) metal ions on the resin had the optimum pH rating in region of 4–6 and reached the equilibrium condition in 40 minutes. The adsorption of Cr(III) and Pb(II) metal ions on the resin follows the Langmuir isothermal pattern with the linearity constant (R2 ) of Cr(III) and Pb(II) adsorption, whose results were 0.9640 and 0.9716, respectively. The adsorption capacity of Cr(III) and Pb(II) metal ions is 323.0 µmole/g and 33.4 µmole/g, while the adsorption energy is 30.4 kJ/mole and 39.7 kJ/mole, respectively. Most parameters in batch systems confirm that resin is a good adsorbent for Cr(III) and Pb(II), though Cr(III) adsorption was more favorable than that of Pb(II). The outstanding adsorption abilities for Cr(III) and Pb(II) metal ions have exhibited good prospects for disposal application of polluted water and environmental protection."

"Kadmium merupakan salah satu logam berat bersifat toksik bagi kehidupan manusia. Dalam konsentrasi yang sangat rendah, logam kadmium tidak dapat ditentukan menggunakan instrumen dengan mudah. Ion Imprinted Polymer (IIP) digunakan untuk mengenali dan memisahkan logam berat. Prinsip kerja dari IIP adalah dengan metode trapping dalam matriks polimer yang terikat silang dengan agen pengkelat. Dalam penelitian ini, IIP melalui metode polimerisasi bulk dengan ion logam kadmium sebagai template, 8-hydroxyquinoline sebagai ligan, MMA sebagai monomer fungsional, EGDMA sebagai crosslinker, dan AIBN sebagai inisiator berhasil disintesis. Pengaruh rasio campuran ligan dan monomer (1:1, 1:2, dan 1:3) terhadap IIP dipelajari pada penelitian ini. Produk IIP dikarakterisasi menggunakan AAS, FTIR, SEM, dan TGA. Kapasitas adsorpsi IIP mencapai kemampuan optimumnya pada pH 6 dengan waktu kontak 60 menit. IIP dengan rasio 1:2 memiliki mekanisme adsorpsi sesuai dengan persamaan Freundlich dengan R² 0.9214 dan kapasitas adsorpsi maksimum sebesar 335.58 mg/g untuk IIP dan 105.46 untuk NIP. Model kinetika adsorpsi dari IIP dan NIP mengikuti model kinetika orde pseudo pertama dengan R² 0.9722. Hasil tersebut menunjukkan mekansime adsorpsi IIP terjadi pada tahap awal reaksi. IIP menunjukkan selektifitas yang baik terhadap ion Cd(II) dengan adanya interferensi logam Pb dan Cr.

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Cadmium become one of toxic heavy metals that can be dangerous for human lives. At very low concentration, cadmium cannot be determined by instrument easily. Ion Imprinted Polymer (IIP) is used to recognize and separating heavy metal ion that works with trapping method in polymer matrices that are crosslinked with chelating agent. In this research, IIP via bulk polymerization with cadmium ion as template, 8-Hydroxyquinoline as ligand, methyl methacrylate as functional monomer, EGDMA as Crosslinker, and AIBN as Initiator was successfully synthesized. The effect of ratio of ligand and monomer (1:1, 1:2, 1:3) to IIP was studied. The synthesized IIP was characterized by AAS, FTIR, SEM, and TGA. Adsorption capacity of IIP reach optimum capacity at pH 6 with 60 minutes contact time. IIP with ratio 1:2 has the adsorption mechanism of both IIP and NIP followed to the Freundlich equation with R² 0.9214 and maximum adsorption capacity of Cd(II) was 335.58 mg/g for IIP and 105.46 mg/g for NIP respectively. Furthermore the kinetics model followed the pseudo first order with R² 0.9722, this results show that the adsorption mechanism took place on initial time of adsorption. IIP exhibited good selectivity to Cd²⁺ ions in the presence of Pb²⁺ and Cr³⁺ interferences."

"Hidrogen adalah salah satu energi terbarukan yang menjanjikan dan berpotensi menjadi pengganti bahan bakar fosil. Namun, aplikasi hidrogen sebagai bahan bakar memiliki kekurangan, yaitu dalam hal penyimpanannya. Dalam suhu kamar dan tekanan atmosfir, hidrogen memiliki rasio energi yang sangat rendah terhadap volumenya jika disimpan dalam bentuk gas sehingga perlu dilakukan berbagai penelitian yang berkaitan dengan metode dan material untuk menyimpan hidrogen terus dilakukan. Sejauh ini metode penyimpanan hidrogen memakai prinsip adsorpsi dengan karbon aktif berbentuk granular sebagai adsorben sangat menjanjikan karena bisa menurunkan tekanan dalam tangki dengan kapasitas penyimpanan yang relatif sama. Pada penelitian ini, karbon aktif yang digunakan pada penelitian ini adalah karbon aktif berbahan dasar zeolite alam. Proses pengambilan data dilakukan dengan metode volumetrik dan tipe adsorpsi yang digunakan adalah adsorpsi isotermal. Penyerapan dilakukan pada 3 temperatur berbeda, pertama pada temperatur 35°C dan tekanan mencapai 40 bar, yang kedua adalah pada temperatur 25°C dan tekanan mencapai 40 bar, dan yang ketiga pada temperatur 0°C dengan tekanan mencapai 40 bar. Pada temperatur 35°C, penyerapan hidrogen sebesar 0.01162kg/kg pada tekanan 39.3620 Bar. Pada temperatur 25°C, penyerapan hidrogen sebesar 0.01991kg/kg pada tekanan 40.2015 Bar. Pada temperatur 0°C, penyerapan hidrogen sebesar 0.03042kg/kg pada tekanan 39.6427 Bar. Data yang didapat selanjutnya dikorelasi dengan menggunakan persamaan model Langmuir, Toth, dan Langmuir-Freudlich.

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Hydrogen is one of promising and potential new energy sources as the substitute of fossil fuel.But, the application of hydrogen as fuel still has weakness in a storage system. Inroom temperature and atmosphere pressure, hydrogen has a very low energy/volume ratio if the hydrogen is stored in gas phase, so it's needed to do some research about the method and materials to adsorp hydrogen. Nowadays, hydrogen adsorption's method using granular activated carbon as the adsorbent is very promising since can reduce the pressure in cell with the adsorption capacity relatively same as other methods. In this research, the activated carbon which used is natural zeolite.

The method which used in this research is volumetric method and the type of adsorption in this research is isothermal adsorption. The adsorptions in this research are in 3 temperatures, first adsorption in 35oC and the pressure up to 40 bars. Then second adsorption in 25°C and the pressure up to 40 bars, and the third adsorption in 0oC. At temperature 35°C, the hydrogen adsorption is 0.01162kg/kg at 39.3620 Bars. At temperature 25°C, the hydrogen adsorption is 0.01991kg/kg at 40.2015 Bars. At temperature 0°C, the hydrogen adsorption is 0.03042kg/kg at 39.6427 Bars.The Data are corelated with some model equations Langmuir, Toth, and Langmuir-Freudlich."

"Model adsorpsi senyawa koordinasi Ni2+-H2O, Ni2+-NH3, Nit+-EDTA dan Nit+-CN pada permukaan alumina digambarkan berdasarkan variasi variabelnya, yaitu pH, spesies ligan dan alumina serta kuat ion. Metode adsorpsi yang digunakan adalah pengguncangan. Pengujian juga dilakukan secara visual dengan menggunakan Scanning Electron Microscope (SEM).Alumina yang digunakan berasal dari AICI3 dengan variasi suhu kalsinasi 600°C dan 900°C. Alumina jenis 1 yang diperoleh dengan pemanasan 600°C merupakan campuran fasa x dan n-alumina, sedangkan alumina jenis 2 merupakan campuran fasa x, ri, 7, 0 dan rc-alumina.Adsorpsi maksimum Ni2+-H2O dan Ni2+-NH3 pada kedua jenis alumina terjadi pada pH 3, sedangkan adsorpsi maksimum sistem yang mengandung Nit+ EDTA dan Ni2+-CN diperoleh pada pH 10. Pengujian dengan Isoterm Adsorpsi Langmuir dan Freundlich pada pH maksimum menunjukkan bahwa proses adsorpsi mengikuti persamaan Langmuir yang membentuk lapisan monolayer pada permukaan homogen.Percobaan menunjukkan bahwa adsorpsi Ni2+-H2O dan Ni2+-NH3 memiliki pola adsorpsi yang sarna dan keduanya lebih mudah teradsorpsi pada alumina jenis 1 yang bersifat lebih asam. Tetapi pada sistem Ni2+-H2O pola adsorpsi tidak dipengaruhi oleh permukaan kuat ion sehingga diperkirakan adsorpsi terjadi pada Bidang Helmholtz dalam akibat adanya interaksi antara ion logam Ni dengan sisi aktif Oksigen pada permukaan alumina. Sedangkan adsorpsi Nit+ NH3 dipengaruhi oleh kuat ion dan diperkirakan terjadi pada Bidang Helmholtz luar akibat terjadinya proses pengendapan senyawa Ni(OH)2 pada permukaan alumina.Adsorpsi sistem campuran Ni2+-H2O dengan Nit+-EDTA dan Nit+ H2O dengan Ni2+-CN menunjukkan pola adsorpsi yang sama, lebih mudah teradsorpsi pada alumina jenis 2 yang bersifat lebih basa dan dipengaruhi oleh kuat ion, sehingga disimpulkan bahwa proses adsorpsi terjadi pada Bidang Helmholtz luar karena adanya interaksi elektrostatik antara ligan yang kaya akan elektron dengan pusat aktif Aluminium pada permukaan alumina, selain terjadinya pengendapan senyawa Ni(OH)2 pada permukaan alumina, pada kondisi pH tinggi.Pengujian dengan Scanning Electron Microscope (SEM) tidak menunjukkan keberadaan Nikel di sekitar permukaan Aluminium yang diamati sehingga disimpulkan tidak ada interaksi langsung antara Nikel dengan Aluminium.

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Adsorption Models of Nickel (II) Coordination Complex Compounds on to the Alumina SurfaceAdsorption models of coordination complex compounds of Ni2+-H20, Ni2+-NH3, Nit+-EDTA and Nit+-CN on to surface of alumina is described by variation of some variables; pH, types of alumina, and the ionic strength.

Sample of alumina synthesized from AIC13. More acidic alumina which is calculated in 6000C provides mixed of x-and n-alumina phase, whereas alumina which is treated in 900°C contains x,n,-y4 and rs-alumina.

Maximum adsorption of Ni2+-H2O and Nit+ NH3 on both type of alumina occurs in pH 3, but systems contain EDTA and CN ligand in pH 10. Test of Isotherm adsorption in the maximum pH give that adsorption process following Langmuir equation to form monolayer adsorbate on homogenous surface.

The result give that adsorption of Ni2+-H2O and Ni2+-NH3 have similar patterns. The difference is Ni2+-H2O adsorpted in Inner Helmholtz Plane by interaction beetwen Ni2+ with Oxygen site of alumina surface and system contains NH3 in Outer Helmholtz Plane by precipitation of Ni(OH)2 on to alumina surface. Adsorption system contains EDTA and CN have another similar patterns and adsorpted in Outer Helmholtz Plane because any electrostatic interaction between ligand and aluminum site of alumina."

"Pencemaran lingkungan merupakan salah satu masalah yang di Indonesia, salah satunya ialah pencemaran lingkungan air oleh zat warna dari industri tekstil dan pakaian. Zat warna merupakan salah satu polutan organik yang keberadaannya sangat berbahaya bagi lingkungan dan ekosistem air karena dapat menyebabkan keracunan, perubahan mutagenik pada makhluk hidup bahkan kematian. Metode adsorpsi dinilai paling efektif untuk mengurangi pencemaran air dan memiliki berbagai macam adsorben dengan penggunaan dan bahan yang mudah serta memiliki nilai efesiensi tinggi. Pada penelitian ini disintesis karbon aktif berasal dari bahan alam, yaitu limbah tandan kosong kelapa sawit yang dimodifikasi ukuran porinya menggunakan silika gel bekas sebagai template dan menggunakan gugus sulfonat di permukaannya. Pada penelitian ini sintesis karbon aktif dengan metode hard template dan untuk pori diisi oleh ekstrak silika dari kaolin. Hasil sintesis diaplikasikan sebagai adsorben dengan methylene blue dan rhodamine B dalam air. Hasil sintesis dikarakterisasi menggunakan FTIR, XRD, BET, dan SEM-EDX untuk mengetahui ikatan kimia, morfologi, dan luas permukaan. Aplikasi adsorpsi zat warna methylene blue dan rhodamine B mencapai kapasitas adsorpsi maksimum pada pH 9 dan waktu kontak 60 menit pada adsorpsi karbon aktif dan karbon aktif tersulfonasi pada methylene blue dan pada pH 5 dan waktu kontak 60 menit pada adsorpsi karbon aktif dan karbon aktif tersulfonasi.

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Environmental pollution is one of the problems in Indonesia, one of which is the pollution of the water environment by dyes from the textile and clothing industry. Dyes are one of the organic pollutants whose existence is very dangerous for the environment and aquatic ecosystems because they can cause poisoning, mutagenic changes in living things and even death. The adsorption method is considered the most effective for reducing water pollution and has various kinds of adsorbents with easy use and materials and has a high efficiency value. In this study, activated carbon was synthesized from natural materials, namely empty palm fruit bunches waste which modified its pore size using used silica gel as a template and using sulfonate groups on its surface. In this study, the synthesis of activated carbon was carried out using the hard template method and the pores were filled with silica extract from kaolin. The result of the synthesis was applied as an adsorbent with methylene blue and rhodamine B in water. Synthesis results were characterized using FTIR, XRD, BET, and SEM-EDX to determine chemical bonding, morphology, and surface area. The adsorption application of methylene blue and rhodamine B dyes achieved maximum adsorption capacity at pH 9 and a contact time of 60 minutes for the adsorption of activated carbon and sulfonated activated carbon on methylene blue and at pH 5 and a contact time of 60 minutes for the adsorption of activated carbon and sulfonated activated carbon."

"[Preparasi zeolit berpori hierarki dari klinoptilolit Kalianda Lampung berhasil dilakukan dengan metode tandem acid-base treatments. Material zeolit alam berpori mikro dimodifikasi dengan menyatukan dua metode yang biasa dilakukan untuk mengubah ukuran mikropori zeolit menjadi mesopori, yaitu perlakuan asam (dealuminasi) dan perlakuan basa (desilikasi). Perlakuan asam diharapkan dapat meningkatkan rasio Si/Al sebagai hasil dari penurunan kadar Al, kemudian dilakukan perlakuan basa yang bertujuan untuk melarutkan sebagian atau menyeimbangkan kadar Si dan mengarahkan pembentukan mesopori dalam kerangka zeolit. Karakterisasi terhadap klinoptilolit raw dan hasil perlakuan asam-basa digunakan instrumen AAS, XRD, FTIR, dan BET surface area. Berdasarkan penelitian, Z-A4B1 memiliki sisi aktif yang cukup besar yang dapat berperan menjadi adsorben ion logam berat Cu(II) yang lebih baik karena kapasitas adsorpsi Z-A4B1 ini 4 kali lipat lebih tinggi daripada kapasitas adsorpsi dari klinoptilolit raw pada waktu optimum dan konsentrasi awal Cu(II) 300 ppm. Nilai KTK Z-A4B1 adalah sebesar 33,27 mg/g yang setara dengan 104,78 meq/100 g zeolit, sedangkan nilai KTK klinoptilolit raw adalah sebesar 72,19 meq/100 g zeolit. Adapun isoterm adsorpsi yang paling sesuai untuk menjelaskan mekanisme adsorpsi Cu(II) pada klinoptilolit berpori hierarki Z-A4B1 adalah model isoterm adsorpsi Freundlich.;Hierarchical zeolites are prepared from Kalianda Lampung clinoptilolite by tandem acid-base treatments. Natural zeolites that are micropore intrinsicly was modified with two familiar methods that mostly used to change micropore size zeolite into hierarchical zeolite; acid treatment (dealumination) and base teratment (desilication). Acid treatments can increase Si/Al ratio of clinoptilolite because of Al content decreasing, then base treatment can balance Si content and aim the mesopore formation in zeolite frameworks. Intensive characterizations of both raw and modified clinoptilolites are conducted using XRD, AAS, FTIR, and BET surface area measurement. In this research, Z-A4B1 has more active sites to adsorb Cu(II) ions because the adsorption capacity of Z-A4B1 is up to 4-fold higher than the adsorption capacity of raw clinoptilolite at its optimum contact time and initial Cu(II) concentration 300 ppm. The CEC of Z-A4B1 is 33.27 mg/g that equals to 104.78 meq/100 g zeolite, besides CEC of raw clinoptilolite is 72.19 meq/100 g zeolite. Therefore, adsorption isoterm that fit to explain the adsorption Cu(II) mechanism at hierarichal zeolite Z-A4B1 is Freundlich isoterm adsorption model., Hierarchical zeolites are prepared from Kalianda Lampung clinoptilolite by tandem acid-base treatments. Natural zeolites that are micropore intrinsicly was modified with two familiar methods that mostly used to change micropore size zeolite into hierarchical zeolite; acid treatment (dealumination) and base teratment (desilication). Acid treatments can increase Si/Al ratio of clinoptilolite because of Al content decreasing, then base treatment can balance Si content and aim the mesopore formation in zeolite frameworks. Intensive characterizations of both raw and modified clinoptilolites are conducted using XRD, AAS, FTIR, and BET surface area measurement. In this research, Z-A4B1 has more active sites to adsorb Cu(II) ions because the adsorption capacity of Z-A4B1 is up to 4-fold higher than the adsorption capacity of raw clinoptilolite at its optimum contact time and initial Cu(II) concentration 300 ppm. The CEC of Z-A4B1 is 33.27 mg/g that equals to 104.78 meq/100 g zeolite, besides CEC of raw clinoptilolite is 72.19 meq/100 g zeolite. Therefore, adsorption isoterm that fit to explain the adsorption Cu(II) mechanism at hierarichal zeolite Z-A4B1 is Freundlich isoterm adsorption model.]"

"Organobentonit berhasil dibuat dengan proses interkalasi Na-Bentonit dengan senyawa Alanin. Bentonit yang digunakan berasal dari Tapanuli, Sumatera Utara. Na-Bentonit dibuat dari bentonit hasil sedimentasi untuk memperoleh kandungan montmorillonit yang terdapat pada bentonit. Kemudian dilakukan penyeragaman kation pada interlayer bentonit dengan Na+ menjadi Na-Bentonit.Hasil penentuan nilai Kapasitas Tukar Kation dengan menggunakan [Cu(en)2]2+, diperoleh nilai KTK sebesar 45,336 mek/100 gram bentonit. Preparasi organobentonit menggunakan Na-Bentonit yang terinterkalasi Alanin, jumlah Alanin yang ditambahkan sesuai dengan 1 KTK dan 2 KTK dengan 3 variasi pH yaitu pH isoelektrik Alanin (pH 6,01), pH < pI (pH 5) dan pH > pI (pH 7). Hasil karakterisasi organobentonit menunjukkan senyawa Alanin telah berhasil terinterkalasi ke dalam bentonit dan terjadi perubahan pada d-spacing.Organobentonit diuji kemampuan adsorpsinya terhadap ion logam berat Pb2+ dan Cd2+ dengan variasi konsentrasi antara 0,1 mM sampai 0,5 mM, dan membandingkan hasilnya dengan kemampuan adsorpsi dari bentonit alam. Berdasarkan data yang diperoleh menunjukkan bahwa kemampuan menyerap ion logam berat Pb2+ dan Cd2+, organobentonit tidak jauh berbeda dibandingkan Na-Bentonit.

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Organobentonite was successfully made with the intercalation process of Na-Bentonite with Alanine compound. The bentonite was from Tapanuli, North Sumatera. Na-Bentonite was made of the bentonite that resulted from sedimentation process to obtain montmorillonite content in bentonite. Then, cation uniformity was done on bentonite interlayer with Na+ became Na-Bentonite.

In determining the value of Cation Exchange Capacity (CEC) by using [Cu(en)2]2+, the value of CEC obtained was 45,336 mek/100 gram bentonite. In the preparation of organobentonite using Alanine intercalated Na-Bentonite, the amount of Alanine added is in accordance to 1 CEC dan 2 CEC with 3 pH variation : isoelectric pH in Alanine (pH 6,01), pH < pI (pH 5), and pH > pI (pH 7). Characterization result of organobentonite shows that Alanine compound has successfully been intercalated into the bentonite and there has been a change in dspacing.

Organobentonite has been tested in its adsorption ability towards heavy metal ions Pb2+ and Cd2+ with the concentration variation lying among 0,1 mM until 0,5 mM and its result has also been compared with the adsorption ability of natural bentonite. Based on obtained data, it shows that organobentonite`s adsorption ability toward heavy metal ions Pb2+ and Cd2+ is not significally different than Na-Bentonite`s."

"Senyawa kromium banyak digunakan dalam industri modern. Senyawa tersebut banyak dibuang begitu saja ke lingkungan sekitar. Teknologi membrane lebih efisien dan efektif dari pada metode konvensional untuk pengolahan limbah. Tujuan penelitian adalah membuat membran yang dapat digunakan dalam proses pemisahan Cr(VI). Membran dibuat dari kitosan dan silika sekam padi. Variasi kitosan dan silika sekam padi yang digunakan (g) adalah 2:1 (A1), 2:2 (A2), 3:1 (B1), dan 3:2 (B2). Membran dibuat dengan menggunakan teknik inversa fasa. Dari hasil karakterisasi SEM diketahui bahwa membran B2 mempunyai pori yang paling besar yaitu 2,58μm. Hasil karakterisasi FTIR menunjukkan adanya ikatan silang antara kitosan dengan silika sekam padi dengan munculnya pita serapan Si-O pada bilangan gelombang 1122-980/cm. Membran A1 dengan ukuran pori paling kecil mempunyai nilai rejeksi terhadap Cr(VI) paling besar yaitu 70%. Penelitian menunjukkan bahwa membran komposit-silika sekam padi cukup efektif untuk menyerap logam Cr(VI) dengan kapasitas adsorpsi rata-rata adalah 1665.85 mg/g.

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Chromium compounds are widely used in modern industry. Many of these compounds are dumped into the surrounding environment. Membrane technology is more efficient and effective than conventional methods for waste treatment. The research objective is to make a membrane separation proce ss that can be applied to Cr(VI). Membranes are made from chitosan and silica rice husks. Variations of chitosan and silica rice husk used (g) are 2:1 (A1), 2:2 (A2), 3:1 (B1), and 3:2 (B2). The membrane is made by using an inverted phase technique. Results of SEM characterization of membranes show that B2 has the largest pores at 2.58 μ m. The FTIR characterization results indicate the presence of crosslinking between chitosan with silica rice husk with the appearance of Si-O adsorption band at wavelength 1122-980/cm. A1 membrane, with the smallest pore size has the greatest rejection value towards Cr(VI) which is 70%. Research shows that the composite membrane of silica rice husk is effective enough to adsorb metal Cr(VI) with an average adsorption capacity of 1665.85 mg/g. "

"[ABSTRAKPencemaran air oleh logam berat Pb (II) akibat kegiatan industri telah menarik perhatian dunia secara signifikan karena memiliki efek yang merugikan bagi lingkungan. Disisi lain melimpahnya senyawa fosfat di perairan menambah masalah eutrofikasi yang menyebabkan alga blomming dan pertumbuhan tanaman air yang tidak terkendali. Adsorpsi merupakan metode yang efektif dengan harga ekonomis untuk mengatasi permasalahan limbah Pb (II) di perairan. Pemanfaatan tanaman air sebagai biosorben telah dikembangkan demi tujuan tersebut namun masih memiliki beberapa kelemahan. Pada penelitian ini, teknik immobilisasi dilakukan pada spesies tanaman air Duckweed (Lemna perpusilla Torr) pada nanopartikel magnetit dengan penambahan Ca-alginat sebagai adsorben yang memiliki efektifitas tinggi. Adsorben tersebut memiliki pH optimum 10, waktu kontak optimum pada menit ke-90, dan suhu 25oC dengan kemampuan mengadsorpsi terbaik hingga 49,28 mg/g (dengan %Adsorpsi 98,55%) dalam penyerapan logam Pb (II). Nanopartikel magnetit akan mempermudah separasi adsorben dengan memberi medan magnet yang kuat. Nilai %Recovery sebesar 77,75% dalam eluen HNO3 1M yang dimiliki adsorben menjadikan adsorben dapat digunakan kembali. Karaterisasi dengan FTIR menunjukkan adanya gugus fungsi yang berperan aktif dalam proses penyerapan logam Pb (II).

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ABSTRACTWater pollution by heavy metals Pb (II) as a result of industrial activities has attracted worldwide attention significantly because it has a detrimental effect on the environment. The abundance of phosphate compounds in water is also adding to the problem of eutrophication which causes blooming algae and aquatic plant growth uncontrolled. Adsorption is an effective method with economical prices to overcome the problems of waste Pb (II) in water. Utilization of water plants as biosorbent been developed for this purpose, but still have some weaknesses. Immobilization technique performed on the species of aquatic plants Duckweed (Lemna perpusilla Torr) on magnetite nanoparticles with the addition of Ca-alginate as an adsorbent which has a high effectiveness. The adsorbent has an optimum pH 10, the optimum contact time within the 90 minute, and temperature of 25oC with the best ability to adsorb up 49.28 mg/g (in %Adsorption 98.55%) in the absorption of Pb (II). With the magnetite nanoparticles will facilitate the separation of the adsorbent with a given magnetic field in its application in water because it has a strong magnetic power. Value%Recovery of 77.75% in 1M HNO3 eluent makes adsorbent can be reused. Characterization with FTIR showed the presence of functional groups that play an active role in the process of absorption of Pb (II).;Water pollution by heavy metals Pb (II) as a result of industrial activities has attracted worldwide attention significantly because it has a detrimental effect on the environment. The abundance of phosphate compounds in water is also adding to the problem of eutrophication which causes blooming algae and aquatic plant growth uncontrolled. Adsorption is an effective method with economical prices to overcome the problems of waste Pb (II) in water. Utilization of water plants as biosorbent been developed for this purpose, but still have some weaknesses. Immobilization technique performed on the species of aquatic plants Duckweed (Lemna perpusilla Torr) on magnetite nanoparticles with the addition of Ca-alginate as an adsorbent which has a high effectiveness. The adsorbent has an optimum pH 10, the optimum contact time within the 90 minute, and temperature of 25oC with the best ability to adsorb up 49.28 mg/g (in %Adsorption 98.55%) in the absorption of Pb (II). With the magnetite nanoparticles will facilitate the separation of the adsorbent with a given magnetic field in its application in water because it has a strong magnetic power. Value%Recovery of 77.75% in 1M HNO3 eluent makes adsorbent can be reused. Characterization with FTIR showed the presence of functional groups that play an active role in the process of absorption of Pb (II)., Water pollution by heavy metals Pb (II) as a result of industrial activities has attracted worldwide attention significantly because it has a detrimental effect on the environment. The abundance of phosphate compounds in water is also adding to the problem of eutrophication which causes blooming algae and aquatic plant growth uncontrolled. Adsorption is an effective method with economical prices to overcome the problems of waste Pb (II) in water. Utilization of water plants as biosorbent been developed for this purpose, but still have some weaknesses. Immobilization technique performed on the species of aquatic plants Duckweed (Lemna perpusilla Torr) on magnetite nanoparticles with the addition of Ca-alginate as an adsorbent which has a high effectiveness. The adsorbent has an optimum pH 10, the optimum contact time within the 90 minute, and temperature of 25oC with the best ability to adsorb up 49.28 mg/g (in %Adsorption 98.55%) in the absorption of Pb (II). With the magnetite nanoparticles will facilitate the separation of the adsorbent with a given magnetic field in its application in water because it has a strong magnetic power. Value%Recovery of 77.75% in 1M HNO3 eluent makes adsorbent can be reused. Characterization with FTIR showed the presence of functional groups that play an active role in the process of absorption of Pb (II).]"