Protein Recovery from Tofu Whey Wastewater Using a Column Reactor: Preliminary Results

ABSTRAK Industri tahu menghasilkan air limbah pekat atau whey (dadih), yang memiliki pH rendah dan bahan organik yang tinggi, sehingga dapat menyebabkan pencemaran lingkungan jika tidak diolah dengan baik. Di sisi lain, salah satu kandungan limbah tahu pekat yaitu protein dapat dimanfaatkan kembali untuk mengurangi potensi pencemaran lingkungan dan diolah lebih lanjut menjadi produk yang bernilai ekonomis. Penelitian ini bertujuan untuk mendapatkan data awal untuk menilai kelayakan penggunaan metode fraksinasi busa untuk pemulihan protein dari limbah tahu pekat. Limbah tahu pekat dalam penelitian kami memiliki konsentrasi protein awal 3.115 mg/l. Percobaan dilakukan dengan menggunakan reaktor fraksinasi busa berbentuk kolom dalam mode semi-curah. Kombinasi tiga laju alir udara (10, 30, dan 60 l/jam) dan tiga konsentrasi limbah tahu pekat (10, 50, dan 100%) diuji. Hasil percobaan menunjukkan bahwa konsentrasi protein awal mempengaruhi pemulihan protein, sehingga diperlukan konsentrasi protein awal sekitar 3.000 mg/l. Rasio pengayaan tertinggi 1,0 ± 0,5, setara dengan pemulihan protein 6 ± 4%, dicapai pada laju alir 10 l/jam dan konsentrasi limbah tahu pekat 100%. Peningkatan laju alir hingga 30 l/jam tidak mengubah rasio pengayaan (0,9 ± 0,2), tetapi meningkatkan pemulihan protein hingga 71 ± 14%. Penelitian lebih lanjut diperlukan untuk parameter-parameter lain seperti konsentrasi protein awal, komposisi limbah tahu pekat, laju aliran udara, ukuran gelembung, holdup cairan, dan desain reaktor. ABSTRACT The tofu industry generates highly-polluted wastewater called whey, which has a low pH and high organic matter, and therefore can cause environmental pollution when not treated properly. On the other hand, one of the whey constituents namely protein can be recovered from the wastewater to reduce its environmental potency and to be further processed as a product that has an economic value. This study aimed to obtain preliminary data to assess the feasibility of using the foam fractionation method for the recovery of protein from tofu whey wastewater. Tofu whey in our study had an initial protein concentration of 3115 mg.L-1. The experiment was performed using a column foam fractionation reactor in a semi-batch mode. Combinations of three air flow rates (10, 30, and 60 L.h-1) and three tofu whey concentrations (10, 50, and 100%) were tested. Our results show that initial protein concentration influenced protein recovery, with a protein concentration of approximately 3000 mg.L-1 required. The highest enrichment ratio of 1.0 ± 0.5, which corresponded to 6 ± 4% protein recovery, was achieved at 10 L.h-1 flow rate and 100% whey concentration. Increasing the flow rate to 30 L.h-1 did not change the enrichment ratio (0.9 ± 0.2), but increased the protein recovery to 71 ± 14%. Further investigation is needed for parameters such as initial protein concentration, whey composition, air flow rate, bubble size, holdup time, and reactor design.