<![CDATA[Abstract: This study aims to evaluate the effectiveness of utilizing biomass and industrial waste materials as environmentally friendly adsorbents in reducing the levels of heavy metal ions Cd(II) and Zn(II) in industrial wastewater. The research sample was a synthetic waste solution with a metal concentration of 10–100 ppm as a model population. The sampling technique used was purposive sampling on four types of adsorbents, namely SCOBY, EDTA-activated teak wood powder, modified fly ash, and iron-magnesium waste. Data were collected through laboratory experiments with metal content measurements using Atomic Absorption Spectroscopy (AAS). Data analysis included Langmuir and Freundlich isotherm methods, as well as pseudo-first and second-order adsorption kinetics models to understand the adsorption mechanism. The results showed that ironmagnesium waste was able to reduce Cd(II) and Zn(II) levels by more than 99%, followed by fly ash and SCOBY biomass with significant efficiency. This study demonstrates the great potential of sustainable adsorbent materials that support the principles of a circular economy and more environmentally friendly waste management solutions. It is recommended to develop industrial scale applications to support the Sustainable Development Goals in the field of providing clean water and proper sanitation.Keyword: Environmentally Friendly Adsorbent, Biomass, Industrial Waste, Heavy Metal Ions, Cd(II), Zn(II) Abstrak: Penelitian ini bertujuan untuk mengevaluasi efektivitas pemanfaatan material biomassa dan limbah industri sebagai adsorben ramah lingkungan dalam menurunkan kadar ion logam berat Cd(II) dan Zn(II) dalam limbah cair industri. Sampel penelitian berupa larutan limbah sintetik dengan konsentrasi logam 10–100 ppm sebagai populasi model. Teknik sampling yang digunakan adalah purposive sampling pada empat jenis adsorben, yaitu SCOBY, serbuk kayu jati teraktivasi EDTA, fly ash termodifikasi, dan limbah besi-magnesium. Data dikumpulkan melalui eksperimen laboratorium dengan pengukuran kadar logam menggunakan Atomic Absorption Spectroscopy (AAS). Analisis data meliputi metode isoterm Langmuir dan Freundlich, serta model kinetika adsorpsi pseudo-orde satu dan dua untuk memahami mekanisme penyerapan. Hasil menunjukkan bahwa limbah besi-magnesium mampu menurunkan kadar Cd(II) dan Zn(II) hingga lebih dari 99%, diikuti oleh fly ash dan biomassa SCOBY dengan efisiensi yang signifikan. Penelitian ini menunjukkan potensi besar material adsorben berkelanjutan yang mendukung prinsip ekonomi sirkular dan solusi pengelolaan limbah yang lebih ramah lingkungan. Disarankan pengembangan skala aplikasi industri guna mendukung tujuan Sustainable Development Goals pada bidang penyediaan air bersih dan sanitasi layak.Kata kunci: Adsorben Ramah Lingkungan, Biomassa, Limbah Industri, Ion Logam Berat, Cd(II), Zn(II)]]>
