Rancangan Desain Sistem Pengolahan Limbah Cair Coffee Shop Hemat Energi Berbasis Aliran Gravitasi

Abstract

The growth of coffee shop businesses has the potential to increase wastewater pollution loads, highlighting the need for treatment systems that are compatible with wastewater characteristics and the technical conditions of small-scale businesses. This study aims to design a gravity-driven wastewater treatment system for coffee shops by considering wastewater characteristics and hydraulic aspects. A quantitative-descriptive approach based on conceptual engineering design was employed, encompassing wastewater quality and quantity characterization, determination of design flow rates, evaluation of treatment alternatives, hydraulic analysis, and unit dimensioning. The characterization results showed average concentrations of BOD, COD, TSS, ammonia, and fecal coliform of 308.77 mg/L, 1,006.57 mg/L, 609.40 mg/L, 20.16 mg/L, and 11.73 × 10⁴ MPN/100 mL, respectively. Multicriteria evaluation identified a treatment train consisting of screening, a grease trap, an equalization tank, a primary settling tank, an Anaerobic Baffled Reactor (ABR), a constructed wetland, and disinfection as the preferred alternative due to its compatibility with wastewater characteristics and its ability to maintain continuous gravity-driven flow between treatment units. At an average flow rate of 5.30 m³/day, the designed treatment unit dimensions satisfied the hydraulic requirements of the system. The proposed design demonstrates the potential application of a gravity-driven coffee shop wastewater treatment system that utilizes elevation differences as the primary mechanism for conveying wastewater between treatment units.