Effect of the Progressive Increase of Organic Loading Rate in an Anaerobic Sequencing Batch Reactor for Biodiesel Wastewater Treatment

The wastewater from the biodiesel industry is an environmental problem, and from a sanitation resources perspective, the anaerobic sequencing batch reactor (ASBR) is an interesting alternative for wastewater treatment. A better understanding of ASBR operation behavior under the progressive increase of the organic loading rate (OLR) is crucial for upscaling. The objective of this study was to monitor an ASBR operating with an OLR ranging from 1.3 to 9.3 kgCOD m−3 d−1. The average chemical oxygen demand (COD) removal efficiencies of the ASBR were 52, 41, 47, and 11% for phases 1, 2, 3, and 4, respectively. The apparent kinetic coefficient, i.e., the rate of degradation of organic matter, was between 0.10 and 1.80 h−1, considering the kinetic model that considers the residual substrate concentration, which was the one that best fit the obtained data. The progressive increase in applied OLR modified the microbial biomass diversity, which in turn influenced the degradation kinetics of the organic matter. In addition, the values of the applied OLR of 5.1 kgCOD m−3 d−1 and a food to microorganism ratio (F/M) of 0.6 kgCOD kgVSS−1 d−1 were shown to be limiting values that promoted the overload of ASBR.

KOMBINASI PROSES KOAGULASI-FLOKULASI DENGAN SEQUENCHING BATCH REACTOR UNTUK MENURUNKAN KANDUNGAN ORGANIK PADA LIMBAH BATIK

Limbah batik memiliki kandungan organik dan warna, yang sulit untuk digredasi. Tujuan penelitian ini mengembangkan teknologi Sequenching Batch Reactor (SBR) yang dimodifikasi dengan adsorben dari tempurung kelapa dan bamboo. Konsentrasi limbah batik awal, untuk COD sebesar 1965 mg/L, warna 1603 mg/L, TSS 1140 mg/L. Pelaksanaan penelitian terbagi menjadi dua tahap, yaitu tahap pertama limbah diolah menggunakan proses koagulasi dan flokulasi, selanjutnya tahap dua menggunakan Sequencing Batch Reactor. Pada tahap koagulasi-flokulasi, menggunakan koagulan PAC (Poly Aluminium Chloride). Sedangkan pada tahap dua yang menggunakan SBR, diatur Hydraulic Retention Time (HRT) dan berat adsorben (tempurung kelapa, bamboo dan zeolite). Hasil penelitian, didapatkan proses koagulasi dan flokulasi mampu menurunkan kandungan organic (BOD5 dan COD) pada kisaran 80%, Total Suspended Solid (TSS )26% dan warna 55%. Sedangkan pada SBR, didapatkan bahwa penambahan adsorben mengoptimalkan pendegradasian kandungan organic. Didapatkan pada HRT optimal 48 jam, jenis adsorben tempurung kelapa optimal menurunkan kandungan BOD5 sebesar 93%, COD 93.7% sebesar , TSS 81% mg/L dan warna 81% mg/L. Kata kunci: kandungan organic dan warna, koagulasi dan flokulasi, sequencing batch reactor (SBR). The organic content and color of batik wastewater make it difficult to grade. The goal of this research was to create a modified Sequenching Batch Reactor (SBR) using adsorbents made from coconut shells and bamboo. The initial concentrations of COD, color, and TSS in batik wastewater were 1965 mg/L for COD, 1603 mg/L for color, and 1140 mg/L for TSS. The research was divided into two stages, with the first stage involving the use of coagulation and flocculation processes, and the second stage involving the use of a Sequencing Batch Reactor. PAC (Poly Aluminum Chloride) coagulant was used for the coagulation-flocculation stage. Meanwhile, the Hydraulic Retention Time (HRT) and the weight of the adsorbent (coconut shell, bamboo, and zeolite) were set in the second stage using SBR. The coagulation and flocculation processes reduced organic content (BOD5 and COD) by 80 %, total suspended solids (TSS) by 26 %, and color by 55 %, according to the results. In SBR, it was discovered that adding an adsorbent improves the decomposition of organic material. The optimal type of coconut shell adsorbent reduced the level of BOD5 by 93 %, COD by 93.7 %, TSS by 81 % mg/L, and color by 81 % mg/L at an optimal HRT of 48 hours. Keywords: Organic material and color, coagulation and flocculation, sequencing batch reactor (SBR).