THEORETICAL STUDY AND DESIGN OF INDUSTRIAL RESIDUE-BASED "NICK-ABSORB" MODULAR BRICK BIOFILTER FOR HEAVY METAL MITIGATION IN RUNOFF WATER Nick-Absorb: Biofilter Brick Modular Berbasis Limbah Industri untuk Mitigasi Logam Berat pada Air Limpasan Industri Nikel

Abstract

The increasing activity of the nickel industry generates residues such as fly ash and slag, as well as runoff that may transport heavy metals into the environment. This condition requires a mitigation approach that can be placed directly along runoff pathways while simultaneously promoting the reuse of residual materials. This study aimed to design and analyze the Nick-Absorb concept as a modular industrial-waste-based biofilter brick for heavy metal mitigation in nickel industry runoff. A descriptive qualitative method with an engineering design approach was employed through literature review, material characterization analysis, and system design. The resulting biofilter brick consisted of 25% fly ash, 25% nickel slag, 25% coconut-shell biochar, and 25% zeolite. The system was designed to operate through three mechanisms: physical filtration to retain suspended particles and sediments, adsorption by biochar, and ion exchange by zeolite. Its modular form enables passive application in drainage channels or runoff points while supporting the reuse of industrial residues and biomass. Nick-Absorb has potential as an alternative mitigation system that integrates technological and sustainability approaches. From an Islamic perspective, the design represents an ikhtiar to reduce environmental degradation and reflects the human responsibility to protect the environment as conveyed in QS. Ar-Rum/30:41. The effectiveness of heavy metal removal requires further experimental validation.