Analisis Distribusi Chemical Oxygen Demand Pada Tahapan Drain Proses Post-Tanning Sebagai Dasar Optimasi Efisiensi Chemical Uptake Industri Penyamakan Kulit

Arianti, Nafla Rahma Dian (2026) Analisis Distribusi Chemical Oxygen Demand Pada Tahapan Drain Proses Post-Tanning Sebagai Dasar Optimasi Efisiensi Chemical Uptake Industri Penyamakan Kulit. Other thesis, Institut Teknologi Sepuluh Nopember.

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Abstract

Industri penyamakan kulit menghasilkan limbah cair dengan beban organik tinggi akibat penggunaan berbagai bahan kimia pada tahap pasca-penyamakan (post-tanning), khususnya retanning, dyeing, dan fatliquoring. Chemical Oxygen Demand (COD) menjadi parameter penting untuk mengevaluasi beban organik tersebut karena mampu merepresentasikan senyawa organik biodegradable maupun non-biodegradable. Penelitian ini bertujuan untuk mengidentifikasi tahapan drain proses post-tanning yang menghasilkan COD tertinggi, menentukan bahan kimia kontributor utama COD, serta mengevaluasi pengaruh optimasi parameter proses terhadap efisiensi chemical uptake dan penurunan COD. Penelitian dilakukan dengan data proses post-tanning skala industri penuh pada empat artikel kulit, yaitu A, B, C, dan D. Sampel limbah cair diambil dari setiap tahapan drain, kemudian dianalisis menggunakan metode closed reflux colorimetric dengan reagen COD Merck dan pembacaan menggunakan spektrofotometer Spektroquant Move 100. Pengujian single chemical dilakukan pada sembilan bahan kimia dengan konsentrasi 5 dan 10% (wt%) dari berat kulit, sedangkan optimasi dilakukan melalui dua pendekatan, yaitu penambahan waktu kontak 30 menit dan pengurangan volume air 50%. Hasil penelitian menunjukkan bahwa tahap fatliquoring merupakan drain dengan COD tertinggi pada seluruh artikel kulit, dengan rentang 42.100 7.600 mg/L dan median 48.350 mg/L. Uji Kruskal-Wallis menunjukkan adanya perbedaan signifikan antar tahapan drain (H = 9,93; p = 0,042), dan uji Dunn’s menunjukkan perbedaan signifikan antara fatliquoring dan fixation (Adj. Sig. = 0,034). Bahan kimia kontributor utama COD adalah Fatliquor 1 pada Artikel A, Syntan Sulfonated pada Artikel B dan D, serta Syntan AC pada Artikel C. Peningkatan konsentrasi bahan kimia dari 5 menjadi 10% terbukti meningkatkan COD secara signifikan (t = 4,47; p = 0,002; Cohen’s d = 1,49). Hasil optimasi menunjukkan bahwa penambahan waktu kontak 30 menit lebih efektif dan konsisten dalam menurunkan COD dibandingkan low float 50%, dengan penurunan COD sebesar 14,75% pada Syntan Sulfonated, 1,75% pada Fatliquor 1, dan 0,60% pada Syntan AC. Penambahan waktu kontak direkomendasikan sebagai strategi optimasi proses untuk meningkatkan chemical uptake dan menurunkan beban COD pada proses retanning/fatliquoring industri penyamakan kulit.
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The leather tanning industry generates wastewater with high organic loads due to the intensive use of chemicals during post-tanning processes, particularly retanning, dyeing, and fatliquoring. Chemical Oxygen Demand (COD) is an important parameter for evaluating organic pollution because it represents both biodegradable and non-biodegradable organic compounds. This study aimed to identify the post-tanning drain stage with the highest COD contribution, determine the main chemical contributors to COD, and evaluate the effect of process parameter optimization on chemical uptake efficiency and COD reduction. The study was conducted using full-scale industrial post-tanning process data from four leather articles, namely A, B, C, and D. Wastewater samples were collected from each drain stage and analyzed using the closed reflux colorimetric method with Merck COD reagents and a Spektroquant Move 100 spectrophotometer. Single chemical tests were carried out on nine chemicals at concentrations of 5 and 10% (wt%), while process optimization was evaluated using two approaches: an additional contact time of 30 minutes and a 50% reduction in water volume. The results showed that fatliquoring was the drain stage with the highest COD in all leather articles, ranging from 42,100 to 57,600 mg/L with a median of 48,350 mg/L. The Kruskal Wallis test indicated a significant difference among drain stages (H = 9.93; p = 0.042), while Dunn’s post-hoc test showed a significant difference between fatliquoring and fixation (adjusted p = 0.034). The main chemical contributors to COD were Fatliquor 1 in Article A, Syntan Sulfonated in Articles B and D, and Syntan AC in Article C. Increasing the chemical concentration from 5 to 10% significantly increased COD (t = 4.47; p = 0.002; Cohen’s d = 1.49). The optimization results showed that increasing the contact time by 30 minutes was more effective and consistent in reducing COD than applying a 50% low-float condition, with COD reductions of 14.75% for Syntan Sulfonated, 1.75% for Fatliquor 1, and 0.60% for Syntan AC. Therefore, increasing the contact time is recommended as a process optimization strategy to
improve chemical uptake and reduce COD load in industrial retanning/fatliquoring processes.

Item Type:	Thesis (Other)
Uncontrolled Keywords:	COD, Chemical Uptake, Fatliquoring, Penyamakan Kulit, Post-Tanning, COD, Chemical uptake, Fatliquoring, Leather Tanning, Post-Tanning
Subjects:	Q Science Q Science > QD Chemistry Q Science > QD Chemistry > QD75.2 Chemistry, Analytic
Divisions:	Faculty of Science and Data Analytics (SCIENTICS) > Chemistry > 47201-(S1) Undergraduate Thesis
Depositing User:	Nafla Rahma Dian Arianti
Date Deposited:	31 Jul 2026 06:49
Last Modified:	31 Jul 2026 06:49
URI:	http://repository.its.ac.id/id/eprint/140516

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