<![CDATA[Abstrak: Semakin meningkatnya aktivitas industri di Kota Jakarta berimbas terhadap bertambahnya jumlah kontaminan yang masuk ke dalam perairan Teluk Jakarta. Senyawa seng (Zn) digunakan dalam banyak industri dan konsentrasinya di Teluk Jakarta telah mencapai ambang batas baku mutu air laut untuk biota laut. Sedimen merupakan komponen penting dalam laut yang mampu mengadsorpsi logam terlarut. Analisis XRD menunjukkan bahwa sedimen Teluk Jakarta didominasi oleh mineral kuarsa sebanyak 56.4%, kaolinite sebanyak 17.5%, dan pyrite sebanyak 13.7% persentase berat. Karakterisasi fisik dan kimia sedimen Ancol mencakup kandungan C-organik sebesar 5.41%, nilai KTK sebesar 29.07 me/100 gram, luas permukaan sebesar 29.388 m2/gram, specific gravity sebesar 2.63 g/cm3, dan keberadaan gugus hidroksil. Percobaan sorpsi dilakukan secara batch dan mengikuti kinetika reaksi pseudo-second order. Adsorpsi Zn oleh sedimen Ancol, Teluk Jakarta pada kondisi tanpa keberadaan kompetitor dapat direpresentasikan dengan isoterm Langmuir. Pada penambahan Na, adsorpsi Zn mengikuti isoterm Freundlich dan terjadi penurunan kapasitas adsorpsi sebesar 0.68%. Pada kondisi penambahan Ca, adsorpsi Zn mengikuti isoterm Langmuir kompetitif, terjadi penurunan kapasitas adsorpsi sebesar 0.91%. Pada penambahan Mg, adsorpsi Zn mengikuti isoterm linear dan terjadi penurunan kapasitas adsorpsi sebesar 2.22%. Pada air laut artifisial, adsorpsi Zn mengikuti isoterm Langmuir dan secara keseluruhan terjadi penurunan kapasitas adsorpsi sebesar 12.09%. Adsorpsi Zn dengan kompetitor Na dan Ca di dalam air laut artifisial dapat direpresentasikan dengan isoterm Langmuir kompetitif. Kata kunci: adsorpsi, Zn, kation kompetitor, sedimen Abstract: Rapid development of industrial activities in Jakarta leads to increasing amount of pollutant in the sea of Jakarta Bay. Zinc (Zn) is a common substance used in many kind of industry. The concentration of Zn in the sea of Jakarta Bay has reached the maximum limit of Zn concentration regulated by Indonesian State Minister for the Environment in the sea for marine biota. Marine sediment plays an important role in adsorption process of dissolved metal in the seawater. XRD analysis of Jakarta Bay sediment shows dominant mineral of the sediment which are quartz (56.4%), kaolinite (17.5%), and pyrite (13.7%). Physical and chemical characterization of Ancol Sediment showed organic carbon content as much as 5.41%, cation exchange capacity 29.07 meq/100 gram, surface area 29.388 m2/gram, specific gravity 2.63 g/cm3 , and the presence of hydroxyl group. A batch sorption model which assumed the pseudo-second order mechanism, was developed to predict the equilibrium sorption capacity. Adsorption of zinc onto Ancol sediment followed Langmuir isotherm. In addition of Na to the system, Zn adsorption followed Freundlich isotherm and sorption capacity decreased by 0.68%. In addition of Ca to the system, Zn adsorption followed Freundlich isotherm and sorption capacity decreased by 0.91%. In addition of Mg to the system, Zn adsorption followed linear isotherm and sorption capacity decreased by 2.22%. In artificial seawater, Zn adsorption followed Langmuir isotherm and sorption capacity decreased by 2.09% compared with absence of competing cation. Adsorption of Zn in presence of each Na and Ca in artificial seawater were specifically compatible with competitive Langmuir isotherm. Keywords: adsorption, Zn, competing cation, sediment]]>
