Case Study of a Small Scale Reverse Osmosis System for Treatment of Mixed Brackish Water and STP Effluent

A case study on utilizing reverse osmosis (RO) technology to fulfill fresh water needs at a mall and a hotel has been done on Bali Island, Indonesia. A mix of brackish water and sewage treatment plant (STP) effluent was used as feed water in the RO system. The system used 36 membrane elements (CSM RE 8040 BLN) arranged into two stages: 8 pressure vessels (PVs) in the first stage and 4 PVs in the second stage, each loaded with 3 membranes. The objectives of this research were to assess the cleaning effectivity in the plant, to evaluate the cleaning of 1 membrane element using a CIP system, and to assess the use of the membrane for filtration in the pre-treatment system. SEM and FTIR analysis indicated that the foulants on the membrane surface were dominated by organic foulants and inorganic deposits. To clean the discarded membrane the proposed method used NaOH solution (pH 12 and pH 13) and citric acid (pH 2 and pH 3). All membranes displayed a dramatic decline in rejection of about 80%. Based on the rejection tests of SO42-, Cl-, turbidity reduction approached 100%. It can be concluded that an RO membrane that has undergone selectivity decline can be re-used as a filtration membrane in the pre-treatment system

Improving Performance Of Low Reverse Osmosis Pressure Systems By Intermittent Autoflushing

Scaling formation on the membrane surface in the form of calcium carbonate, calcium sulphate, silica, and/or magnesium silicate is a main problem of the reverse osmosis (RO) application for upgrading low grade water. Scaling in RO system is generally controlled by softening the feed water, limiting the recovery and/or the addition of antiscalants which is impractical for household RO system. In this work, the feasibility of intermittent autoflushing to prevent scale formation in household RO systems was investigated. All experiments were carried out using commercially available RO membrane (CSM RE-1812LP) which operated for 6 hours under operating pressure 5 kg/cm2 and total recycle operating mode. Model solution of feed water contain CaCl2 and NaHCO3 were prepared to meet various LSI values in the range of 0 to 1.5. Duration and interval time of autoflush were in the range of 60 to 15 s and 5 to 60 min respectively. The results shown that the permeate flux of the system which operated using intermittent autoflushing relatively stable. It is emphasized that intermittent autoflushing may improve the performance of household reverse osmosis systems

PENYISIHAN AMONIAK DAN KEKERUHAN PADA SISTEM RESIRKULASI BUDIDAYA KEPITING DENGAN TEKNOLOGI MEMBRAN BIOFILTER

Crabs are one of the economically valuable commodities. Barriers that often occur in crab farming in ponds is limited land and water. Crab aquaculture activities can not be apart from the waste generated, which can cause water quality degradation, especially of food remains, feases and the metabolism of the crabs. Waste produced as ammonia is toxic at high concentrations and high turbidity can cause death in the crabs. Alternative technologies are used to decrease the production of crabs due to lack of availability of land and water degradation are water recirculation system using a membrane biofilter. Membrane biofilter is used to maintain the water quality is to eliminate ammonia to levels not exceeding 0.1 ppm, and removing turbidity to <30 NTU. Biofilter is used to eliminate ammonia by nitrification and denitrification process using aerobic and anaerobic mikrroorganisme. Membranes which is used to reduce turbidity is ultrafiltration membranes. Flux on the membrane will determine the performance of the membrane. If the flux decreased 85% from the initial flux, indicating the occurrence of fouling on membrane. This fouling can be overcome by washing. One of it is the backwash. Using biofilter can reduce of ammonia from 4,41 mg/L up to 1,48 mg/L during 7 days. Turbidity can be reduced by using ultrafiltration membrane. In the Ultrafiltration membrane fouling control can be done by backwash 30 minutes 15 seconds. This is indicated by the high flux of the membrane

Tekno-Ekonomi Sistem Membran Terintegrasi untuk Pengolahan Air Baku Campuran Air Payau dan Efluen STP

Recently, portable water supply is one of crucial problems in the world, including Indonesia because water is not a cheap natural resource. Saline waters such as brackish water, seawater, and wastewater have been used as alternative raw water sources to fulfil domestic and idustrial water demands. Water price higher than IDR 15,000 clearly indicate that treatment of brackish water and/or wastewater reuse is effective from cost point of view. This work is aimed to perform in-situ pilot test by involving user and investor directly. Moreover, technical and cost are analysed based on a case study, i.e. average production of 220,000 m3/year; water price of IDR 14,500/m3 that increase IDR 2,000 every two years. This water treatment plant requires capital cost of 3.5 billions rupiahs. The capital comes from bank loan with interest of 13% per annual. It is found that with contract duration of 10 years, net present value (NPV) is positive so that this investment is feasible

Fouling dan Cleaning Membran Reverse Osmosis Tekanan Rendah untuk Aplikasi Daur Ulang Air Limbah Domestik

Separation process by reverse osmosis membrane for wastewater reuse is an advantage process because of feasible cost and able to produce high quality of product water. The used of RO membrane on wastewater reuse application is often limited by fouling phenomena, that is the accumulation of some types of foulant on the membrane surface. An understanding of the foulant types and the fouling mechanism is the key to success in RO membrane chemical cleaning. This review discusses numerous works about the fouling mechanisms and cleaning procedures

Fouling dan Cleaning Membran Reverse Osmosis Tekanan Rendah untuk Aplikasi Daur Ulang Air Limbah Domestik

Separation process by reverse osmosis membrane for wastewater reuse is an advantage process because of feasible cost and able to produce high quality of product water. The used of RO membrane on wastewater reuse application is often limited by fouling phenomena, that is the accumulation of some types of foulant on the membrane surface. An understanding of the foulant types and the fouling mechanism is the key to success in RO membrane chemical cleaning. This review discusses numerous works about the fouling mechanisms and cleaning procedures

Modifikasi Asam Suksinat - Gelombang Pendek untuk Produksi Tapioka Suksinat

Indonesia as tropical country has great cassava potency. The great chance of cassava product development could be increased its added value through modified tapioca processing. One of modified starch that could be implemented as a food additive is succinic starch. The tapioca succinilation processed through combination process of reacting tapioca with succinic acid and microwave treatment. The research method was conducted by factorial design with 3 factors: substrate concentration (30 %, 40 %), succinic acid concentration (1 %, 3 %, 5 %), and drying method (oven and microwave). Succinic tapioca was analyzed both physical and chemical characteristics, while optimal product was fur- ther analyzed for nutrition contents and surface microstructure using SEM. Succinic acid and microwave modification influenced to the physical and chemical succinic tapioca, except ash content. The highest substitution degree value was 0.929 which was obtained by combination of substrate concentration 40 %, succinic acid added 5 % and microwave processed. The change of granule size was not significant, just the distribution among granule correlated with the tapi- oca modification. The succinic tapioca granule size ranged 5.35 µm until 17.20 µm with average 11.15 µm. Succinic tapioca characteristic hopefully could be advanced food implementation.ABSTRAKIndonesia merupakan negara tropis yang memiliki potensi produksi ubi kayu yang cukup besar. Peluang pengem- bangan produk berbasis ubi kayu di Indonesia masih cukup besar diantaranya yaitu peningkatan nilai tambah ubi kayu melalui proses modifikasi tapioka. Salah satu potensi pati termodifikasi yang dapat dipergunakan untuk bahan tambahan makanan yaitu pati suksinat. Pada penelitian ini proses suksinilasi tapioka dilakukan dengan cara mereak- sikan asam suksinat yang dikombinasikan dengan mempergunakan microwave. Metodologi penelitian yang dilakukan menggunakan rancangan faktorial dengan 3 faktor, yaitu konsentrasi substrat (30 %, 40 %), konsentrasi asam suksinat (1 %, 3 %, dan 5 %), serta metode pengeringan (oven dan microwave). Produk pati suksinat yang dihasilkan dianalisa secara fisik dan kimia, sedangkan produk optimal dianalisa lanjut komposisi nutrisinya dan SEM. Modifikasi asam suksinat –gelombang pendek mempengaruhi hasil analisa baik secara fisik maupun kimia kecuali untuk kadar abu. Nilai derajat subsitusi tertinggi yaitu 0,929 yang dapat diperoleh dengan perlakuan konsentrasi substrat 40 %, pe- nambahan asam suksinat 5 % serta kombinasi microwave. Perubahan ukuran diameter dari granula pati cukup tidak berbeda dibandingkan dengan kontrol, hanya perbedaan kedekatan antar granula yang semakin meningkat dengan adanya perlakuan terhadap tapioka. Ukuran granula pati suksinat berkisar antara 5,35 µm hingga 17,20 µm, den- gan diameter rata-rata 11,15 µm. Karakteristik produk pati suksinat, sebaiknya dapat digunakan untuk implementasi proses produksi pangan lanjut

C3 Paper

Ultrafiltration (UF) has been proposed as a promising technology in recirculating aquaculture systems (RAS) to remove both organic contaminants and other fine contaminants including viruses and pathogenic bacteria. However, fouling is still a severe problem during this application. This paper investigated the fouling behavior of three different UF membranes examined using five different aquaculture contaminants. The experiments were performed using UF membranes with molecular weight cut-off 10, 50, and 100 kDa. Humic acid, shrimp feed, Spirulina sp., Vibrio harveyi and IHHNV were used as contaminant models. Scanning electron microscope was used to visualize the presence of foulant on the membrane surface. The results showed that fouling behavior was affected by both membrane cut-off (pore size) and foulant type. Two fouling behaviors were observed: (i) rapid flux decline at the early stage of filtration followed by relatively constant permeate flux until experiments finished, and (ii) rapid flux decline at the early stage of filtration followed by a gradual decrease in permeate flux. Due to its reliable flux value and high rejection, 100 kDa UF membrane should be considered as the most suitable UF membrane for RAS application

EDUKASI TEKNOLOGI MEMBRAN UNTUK PENYEDIAAN AIR BERSIH DI KECAMATAN SEMARANG SELATAN -JAWA TENGAH

Air merupakan kebutuhan dasar bagi manusia, kebutuhan akan air bersih terus meningkat seiring dengan pertumbuhan manusia. Jumlah air di bumi cenderung tetap, namun kualitas air terus menurun akibat pencemaran. Oleh sebab itu perlu adanya upaya pengolahan air menjadi air bersih sebelum di konsumsi. Semarang selatan merupakan sebuah kecamatan di Kota Semarang yang memiliki posisi strategis karena dekat dengan kota. Letak daerah yang berada pada daerah padat penduduk mengakibatkan sulitnya akses air bersih. Air yang diambil dari air sumur memiliki kualitas yang kurang bagus dimana air yang dihasilkan sedikit keruh dan berbauh amis. Selama ini warga berinisiatif menggunakan tawas sebagai bahan untuk menjernihkan air, namun residu tawas dalam air menyebabkan gangguan kesehatan pada tubuh. Oleh sebab itu, pengolahan menggunakan membran diterapkan untuk mengolah air tersebut menjadi lebih bersih. Teknologi membran tidak membutuhkan bahan kimia tambahan serta biaya operasi yang cukup murah. Kegiatan penyuluhan teknologi membran untuk mengolah air bersih telah dilakukan di Kelurahan Bulustalan Rt 02 RW 03 Kecamatan Semarang Selatan. Sebagai luaran dan juga hasil dari pengabdian ini, dibuatlah makalah/modul pelatihan perancangan filtrasi membran skala rumah tangga untuk mengolah air sumur tercemar menjadi air bersih yang layak konsumsi.