Enzymatic hollow fiber membrane bioreactor for penicilin hydrolysis

Continuous enzymatic reaction has been proven as an efficient technique for several industrial applications. In this study, a type of hollow fiber membrane bioreactor where penicillin acylase entrapped within membrane pores was applied to continuously hydrolyze Penicillin G The influences of various operating conditions on immobilization and enzymatic reaction processes were assessed. Amathematical model of the reactor behaviour at steady state condition was also developed. The immobilization results show that penicillin acylase was entrapped more than 90% (100,000 u.a m-?). Due to the much smaller size of 6-APA compared to the membrane pore, the solute diffuses freely through the membrane. However, the immobilized enzyme membrane retained around 35% of the solute. In addition, K,,, of immobilized penicillin acylase (8.04 mM) was slightly higher than that of free penicillin acylase (7.75 mM). The theoretical results indicated that convective transport was the main mechanism of mass transport even in the case where flux was very low. Low flux rate is important to avoid gel formation or enzyme release from membrane pores and to maximize the degree of conversion

Bioreaktor Membran untuk Reaksi Enzimatik Penisilin G

Bioreaksi kontinyu telah diketahui sebagai suatu cara efisien untuk diaplikasikan pada industri. Pada penelitian ini, dua jenis bioreaktor (suatu reaktor enzim yang dilengkapi dengan membran filtrasi aliran melintang bioreaktor dengan serat berongga) digunakan untuk menghidrolisis Penisilin G secara kontinyu. Percobaan menggunakan dua membran komersial, yaitu mikrofiltrasi dengan ukuran pori 0,2 µm dari x-flow dan ultrafiltrasi dengan BM 30.000 dari DDSS. Selanjutnya suatu model empiris dikembangkan untuk menggambarkan dinamika fluks pada ultrafiltrasi. Hasil percobaan menunjukkan bahwa membran ultrafiltrasi memberikan rejeksi yang lebih tinggi (15 LMH) dan rejeksi yang lebih tinggi (99,2%) dicapai dengan membran ultrafiltrasi. Secara umum, konversi yang dicapai berada pada kisaran 22 – 99 %, dan ini lebih rendah dari sistem batch. Konversi substrat yang tinggi sangat penting untuk menurunkan kehilangan substrat dan menurunkan biaya proses. Pada sistem bioreaktor dengan serat berongga, hal ini dapat dilakukan dengan menurunkan kecepatan fluks dan mempengaruhi waktu tinggal substrat. Kecepatan fluks yang rendah juga penting untuk menghindari pembentukan gel pada permukaan membran.   Kata kunci : reaktor enzim, mikrofiltrasi, ultrafiltrasi, penisilin

Flux Continuity in Membrane Bioreactor for Azo Dye Biodegradation

A modified activated sludge, contact stabilization process coupled with anoxic reactor and combined with external ultrafiltration membrane is used for azo dye biodegradation. Feed consists of azo dye Remazol Black V and co-substrate tempe industry wastewater as organic source. Hydraulic retention time (HRT) of contact, stabilization and anoxic tank are kept in 2, 4 and 3 hours respectively. To obtain the expected HRTs control of the flux stability is required. In this research the performance of two kinds aerobic-anaerobic membrane bioreactor with and without aeration modes on flux continuity is studied. The first mode, air is injected to the feed channels prior discharges into the membrane so that mixed liquor circulates within the bioreactor. In the second mode, the mixed liquor flows only by pump pressure without aeration to feed channels. Flux continuity of the MBRs with and without aeration, backflush effect is evaluated to achieve the required HRT. Both introducing aeration and without aeration on the feed channel of the membrane can keep flux stable by creating wall shear stress and so suppress membrane fouling. However, increasing biomass concentration in bioreactors results in more frequent backwashing, so that aerated MBR is more preferred. Due to changing of permeate rate caused the HRT of stabilization tank changes to 3.98 hrs for non aerated MBR, whereas the HRT of MBR with alternate filtration-backflush time is 4.10 hours

PENGOLAHAN ZAT WARNA AZO MENGGUNAKAN BIOREAKTOR MEMBRAN KONSEKUTIF AEROB-ANAEROB

Zat warna azo merupakan salah satu grup zat warna sintetis yang paling banyak digunakan di sejumlah industri seperti tekstil, makanan, kosmetik dan pencetakan kertas. Pengolahan zat warna azo dengan metoda biologi dianggap ramah lingkungan karena dapat memineralisasi senyawa organik secara sempurna dengan biaya rendah. Akan tetapi zat warna azo bersifat rekalsitran untuk dibiodegradasi karena bersifat xenobiotik. Namun mikroorganisme dapat mengembangkan sistem enzim untuk biodegradasi dan mineralisasi zat warna pada kondisi lingkungan tertentu. Biodegradasi zat warna azo dapat dilakukan pada kondisi anaerob, anoksik dan aerob. Berbagai mekanisme pada pemutusan reduktif zat warna azo, meliputi mekanisme enzimatis, melalui penambahan mediator redoks berat molekul rendah, melalui reduksi kimia. Pemutusan ikatan azo menimbulkan pembentukan amina aromatik. Degradasi amina aromatik tergantung pada struktur kimia dan kondisi lingkungan. Pada telaah pustaka ini akan dibahas tentang biodegradasi dan mekanisme pemutusan warna, kemudian akan diusulkan suatu teknologi pengolahan air buangan yang mengandung zat warna azo, khususnya pengolahan biologi. Dari hasil telaahan, diperoleh sistem bioreaktor membran (BRM) sebagai alternatif teknologi pengolahan limbah untuk mengolah limbah dengan kandungan senyawa toksik seperti zat warna azo sekaligus senyawa organik, sehingga dihasilkan kualitas efluen yang jauh lebih baik dibandingkan proses pengolahan limbah konvensional. Pengolahan BRM aerob-anaerob lebih efektif untuk dikembangkan, dibandingkan dengan proses anaerob-aerob. Konfigurasi reaktor ini dapat dilakukan dalam suatu reaktor tunggal dengan resirkulasi efluen proses anaerob ke proses aerob untuk penyempurnaan degradasi amina aromatik

KINERJA BIODEGRADASI ZAT WARNA AZO MENGGUNAKAN BIOREAKTOR MEMBRAN ANOKSIK-OKSIK KONTINU PADA UMUR LUMPUR YANG BERBEDA

Umur lumpur dalam bioreaktor merupakan salah satu parameter kontrol yang penting terutama untuk penyisihan senyawa toksik, salah satunya adalah zat warna azo. Dalam penelitian ini akan diamati pengaruh umur lumpur terhadap penyisihan zat warna azo menggunakan modifikasi proses lumpur aktif kontak-stabilisasi serta reaktor anoksik yang dikombinasikan dengan membran ultrafiltrasi eksternal. Umpan terdiri dari campuran zat warna azo Remazol Black-5 pada konsentrasi 110-120 mg/L dan limbah tempe sebagai ko-substrat. Variasi umur lumpur 1,2 dan 5 hari dilakukan pada HRT tangki kontak, stabilisasi dan anoksik konstan yaitu 2, 4 dan 4 jam. Dari percobaan diperoleh umur lumpur 5 hari merupakan umur lumpur yang optimal dengan penyisihan warna dan senyawa organik sampai 64% dan 81%. Tangki anoksik berkontribusi paling tinggi pada penyisihan warna dan COD terhadap penyisihan keseluruhan, diikuti oleh tangi stabilisasi, sedangkan tangki kontak tidak terlalu signifikan pada penyisihan warna maupun senyawa organik sebaliknya membran eksternal sebagai pengganti proses sedimentasi pada proses lumpur aktif konvensional berperan cukup signifikan dalam penyisihan warna keseluruhan, namun kontribusinya terhadap penyisihan COD total tidak terlalu signifikan

COMBINATION OF REVERSE OSMOSIS AND ELECTRODEIONIZATION FOR SIMULTANEOUS SUGAR RECOVERY AND SALTS REMOVAL FROM SUGARY WASTEWATER

An integrated membrane system combining reverse osmosis (RO) and electrodeionization (EDI) is used for simultaneous sugar concentration and salts removal from a synthetic dilute sugar solution as a model of sugar-containing wastewater. The RO system uses a thin film composite RO membrane (Saehan CSM, RE1812-60). Meanwhile, the EDI stack has two diluted compartments, one concentrated compartment, one anode compartment, and one cathode compartment. Commercially available cation exchange membrane (MC-3470) and anion exchange membrane (MA-3475) are used as ionic selective barriers of the EDI stack. Both diluate and concentrate compartments are filled with mixed ion exchange resins (purolite strong acid cation exchange, C-100E and strong base type I anion resins, A-400). Two different operation modes, i.e. RO-EDI and EDI-RO, were assessed. The experimental results show that the observed sugar rejection of RO membrane is more than 99.9% and there is no sugar loss in the EDI stack. This indicates that the hybrid process allows almost total sugar recovery. In addition, significant reduction of salts content from the concentrated sugar solution is obtained. From permeate flux and permeate purity points of view, however, the EDI-RO configuration seems superior to the RO-EDI configuration. It should be emphasized that scale formation on the membrane surface of the concentrate compartment side has to be controlled

Performance of a novel electrodeionization technique during citric acid recovery

This paper concerns with the behavior of an electrodeionization (EDI) system for concentration of citric acid from fermentation broth. Commercially cation-exchange membrane (MC-3470) and anion-exchange membrane (MA-3475) were used as ionic selective barriers of the EDI stack. The diluted compartments of the EDI stack were filled with mixed ion-exchange resins (purolite strong acid cation-exchange, C-100E and strong base type I anion resins, A-400). The experiment used feeds with citric acid concentration in the range of 500–10,000 ppm and feed flow rate in the range of 1–4 l h−1. The V–I characteristics indicated that there were essential differences in current transport and electrical resistance between the EDI and the electrodialysis (ED) processes. Moreover, the overall current efficiency was in the range of 40–96% and has been found to be a function of feed concentration and current density. The performance of the EDI system was also stable during 24 h operation

Hydrogenation of Maltose in Catalytic Membrane Reactor for Maltitol Production

Maltitol is one of the low-calorie sweeteners which has a major role in food industries. Due to its characteristics of comparable sweetness level to sucrose, maltitol can be a suitable sugar replacement. In this work, catalytic membrane reactor (CMR) was examined in maltitol production through hydrogenation of maltose. Commercial ceramic membrane impregnated with Kalcat 8030 Nickel was used as the CMR. The reaction was conducted at a batch mode operation, 95 to 110°C of temperature, and 5 to 8 bar of pressure. In the range of working conditions used in this study, up to 47% conversion was achieved. The reaction conversion was significantly affected by temperature and pressure. Results of this preliminary study indicated that CMR can be used for hydrogenation of maltose with good performance under a relatively low operating pressure