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All Journal Jurnal Presipitasi : Media Komunikasi dan Pengembangan Teknik Lingkungan Sainteks: Jurnal Sain dan Teknik
Johan Syafri Mahathir Ahmad
Universitas Gadjah Mada
Agriculture, Biological Sciences & Forestry Chemical Engineering, Chemistry & Bioengineering Chemistry Decision Sciences, Operations Research & Management Earth & Planetary Sciences Engineering Industrial & Manufacturing Engineering

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The Study of Tuff Breccia for Batik Wasterwater Treatment Media in Bayat, Klaten District, Central Java Wawan Budianta; Johan Syafri Mahathir Ahmad; I Wayan Warmada
Sainteks: Jurnal Sain dan Teknik Vol 5 No 1 (2023): Maret
Publisher : Universitas Insan Cendekia Mandiri

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.37577/sainteks.v5i1.531

Abstract

Batik wastewater produced in the batik industry in Bayat, Klaten Regency, contains chromium and phenol, which pass the wastewater quality standard. This study aimed to evaluate the ability of tuff breccia from the study area to reduce chromium and phenol concentration in batik wastewater. Mineralogical and chemical characterization was conducted to investigate tuff breccia's mineralogical and chemical composition. A batch and regeneration test was conducted to investigate tuff breccia's ability to reduce the chromium and phenol concentration in the batik wastewater. The characterization of tuff breccia indicates that the tuff breccia consists of fragments, minerals (quartz, plagioclase), and clay minerals (smectite and illite). The batch test results show that the grain size of tuff breccia and the pH value significantly influence the ability of tuff breccia to reduce the chromium and phenol concentration in batik wastewater. The regeneration test showed that the tuff breccia would decrease the capability by up to 30 percent after five times of use.
Performance Evaluation and Operational Optimization of a Fine-Bubble Porous–Venturi Aeration System Niesa Hanum Mistoro; Sri Puji Saraswati; Johan Syafri Mahathir Ahmad; Henny Sudibyo; Dahlia Anggita Zahra
Jurnal Presipitasi : Media Komunikasi dan Pengembangan Teknik Lingkungan Vol 23, No 2 (2026): July 2026
Publisher : Universitas Diponegoro

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/presipitasi.v0i0.%p

Abstract

Aeration is the most energy-intensive unit in wastewater treatment systems, particularly in shallow decentralized reactors with limited hydrostatic pressure, which, which reduces oxygen transfer efficiency. However, systematic evaluations of integrated porous–Venturi microbubble systems under shallow-water conditions are limited. This study aims to address this gap by investigating and optimizing a fine-bubble porous–Venturi microbubble generator (MBG) using laboratory-scale experiments. Clean water experiments were conducted in a 200 L batch reactor with two liquid flow rates (71.6 and 103.8 L/min) and four gas flow rates (0.15–0.60 L/min). Aeration performance was assessed using the volumetric oxygen mass transfer coefficient (KLa(20)), standard oxygen transfer rate (SOTR), and specific aeration efficiency (SAE), supported by one-way ANOVA. The results showed that the gas flow rate influenced  KLa(20) and SOT,R whereas the liquid flow rate had a dominant effect on SAE. The optimal operating conditions were identified as QL = 71.6 L/min and QG = 0.45 L/min, achieving KLa(20) of 2.23 h⁻¹ and SAE exceeding 40 kg O₂/kWh. The findings showed that optimum gas–liquid interaction leads to energy-efficient aeration performance rather than maximum flow rate supply. It also provides practical design insights for optimizing aeration systems in shallow and decentralized wastewater treatment applications
Co-Authors Dahlia Anggita Zahra Henny Sudibyo I Wayan Warmada Niesa Hanum Mistoro Sri Puji Saraswati Wawan Budianta