Water Quality Assessment of Akkarena Beach: A Local Case for Global Coastal Sustainability

Abstract

This study investigated the production of coal briquettes from raw coal waste using a non‑carbonization method at SMK‑SMAK Makassar. The objective was to determine the manufacturing procedure and evaluate the briquette quality based on Indonesian National Standard (SNI) 13‑4931‑2010 parameters: ash, moisture, volatile matter, total sulfur, and calorific value. Laboratory analyses met the ash content (≤20 % SNI) and Sulphur content (≤1 % SNI) limits, with measured value 9.41 % and 0.375 %. Moisture (≤17 % SNI) was 9.65 %, and calorific value (4000‑5000 cal g⁻¹) was 5,376 cal g⁻¹, also within limits. However, volatile matter (< 22 % SNI) measured 36.59 % exceeded the SNI limit indicating potential combustion inefficiency. Despite this, the briquettes demonstrated favorable ignition characteristics (initial flame 9 min, total burn 32 min) and a high energy density, suggesting they can serve as an alternative solid fuel for households and small‑scale industry. Further research, supported by educational institutions and government agencies, is recommended to reduce volatile matter content and promote broader adoption of coal briquette technology.