Mata KuliaKode MK / Sks / Smtr Program Studi Dosen Desain Instalasi Pengolah Air Limbah (IPAL) 1309701 / 4 sks / VII Teknik Lingkungan Fakultas Teknik Sipil dan Perencanaan Institut Teknologi Adhi Tama Surabaya [ITATS} Taty Alfiah, ST.MT. Diagram Alir IPAL TatyAlfiah/Minggu, 22 September 2013 Hlm - 1 are preliminary. organic matter and.2 . memanfaatkan mikroorganisme. secondary. and biological processes and operations to remove solids. Bertujuan untuk menurunkan materi organic dalam limbah cair. Preliminary Treatment TatyAlfiah/Minggu. misal kadar Nitrat. in order of increasing treatment level. primary. sometimes. nutrients from wastewater. untuk mengilangkan materi anorganik) pengolahan sekunder / secondary treatment (merupakan pengolahan biologis. chemical. untuk menurunkan konsentrasi kontaminan yang masih ada.) pengolahan lumpur / sludge treatment / solid handling (lumpur yang mengandung banyak mikroorganisme. 22 September 2013 Hlm . rancu dengan pengolahan pertama) pengolahan pertama / Primary treatment (pengolahan fisik. Secara garis umum. and tertiary and/or advanced wastewater treatment. harus “dimatikan” sebelum dibuang) pengolahan tersier / Tertiary and/or advanced wastewater treatment (apabila masih diperlukan. adalah gambaran dari urutan / tahapan pengolahan limbah cair dalam suatu IPAL. General terms used to describe different degrees of treatment. Phosphat) Bacaan tambahan Conventional wastewater treatment consists of a combination of physical. tahapan pengolahan limbah cair secara konventional adalah sebagai berikut: pengolahan pendahuluan / Preliminary Treatment (bila diperlukan.Diagram alir pengolahan limbah. 50 to 70% of the total suspended solids (SS). The main purpose of primary treatment is to produce both a generally homogeneous liquid capable of being treated biologically TatyAlfiah/Minggu. commonly called primary clarifiers or primary sedimentation tanks. and taken to the landfill for disposal. and heavy metals associated with solids are also removed during primary sedimentation but colloidal and dissolved constituents are not affected. is strained to removed all large objects that make their way into the sewer system. The effluent from primary sedimentation units is referred to as primary effluent. The grit is removed from the channel. added to the larger objects removed by the bar screens. Many plants have a sedimentation stage where the sewage is allowed to pass slowly through large tanks. These objects can be anything from rags and sticks to toys. which come in a variety of shapes and sizes. Another component of Preliminary Treatment is the grit channel where the velocity of the incoming wastewater is carefully controlled to allow sand. The influent flows across these screens. cans and even snakes. are used to remove the items. Some organic nitrogen. or influent. objects catch on the screens.During Preliminary Treatment. Preliminary Treatment is vital for preventing damage to pumps and other equipment in the remaining treatment stages. and 65% of the oil and grease are removed during primary treatment. and the removal of materials that will float (scum) by skimming. grit. organic phosphorus. Generally bar screens. The tanks are large enough that sludge can settle and floating material such as grease and oils can rise to the surface and be skimmed off. Approximately 25 to 50% of the incoming biochemical oxygen demand (BOD 5). the incoming raw sewage. 22 September 2013 Hlm .3 . Primary treatment The objective of primary treatment is the removal of settleable organic and inorganic solids by sedimentation. and stones to settle to the bottom of the channel while keeping the majority of the suspended organic material in the water column. are raised out of the water and are then raked (either mechanically or manually) off the screens. The sedimentation tanks used in secondary treatment. operate in the same basic manner as the primary clarifiers described previously. High-rate biological processes are characterized by relatively small reactor volumes and high concentrations of microorganisms compared with low rate processes.and a sludge that can be separately treated or processed. The microorganisms must be separated from the treated wastewater by sedimentation to produce clarified secondary effluent.4 . NH3. The clarified water flows on to the next step of treatment. 22 September 2013 Hlm . often referred to as secondary clarifiers. and H2O). Secondary treatment processes can remove up to 90% of the organic matter in wastewater by using biological treatment processes. The two most common conventional methods used to achieve secondary treatment are attached growth processes and suspended growth processes. Secondary treatment The objective of secondary treatment is the further treatment of the effluent from primary treatment to remove the residual organics and suspended solids. and the bacteria consume most of the organic matter in the wastewater as food. Aerobic biological treatment (see Box) is performed in the presence of oxygen by aerobic microorganisms (principally bacteria) that metabolize the organic matter in the wastewater. Wastewater passes over the media along with air to provide oxygen. Primary clarifiers are usually equipped with mechanically driven scrapers that continually drive the collected sludge towards a hopper in the base of the tank from where it can be pumped to further sludge treatment stages. Attached Growth Processes In attached growth (or fixed film) precesses. fungi and other microorganisms grow and multiply on the surface of stone or plastic media. Several aerobic biological processes are used for secondary treatment differing primarily in the manner in which oxygen is supplied to the microorganisms and in the rate at which organisms metabolize the organic matter. forming a microbial growth or slime layer (biomass) on the media. the growth rate of new organisms is much greater in high-rate systems because of the well controlled environment. Consequently. In most cases. TatyAlfiah/Minggu. are normally combined with primary sludge for sludge processing. secondary treatment follows primary treatment and involves the removal of biodegradable dissolved and colloidal organic matter using aerobic biological treatment processes. The biological solids removed during secondary sedimentation. called secondary or biological sludge. thereby producing more microorganisms and inorganic end-products (principally CO2. bacteria. algae. the water is pumped to secondary clarifiers where any leftover solids and the microorganisms sink to the bottom. The suspended growth process speeds up the work of aerobic bacteria and other microorganisms that break down the organic matter in the sewage by providing a rich aerobic environmnet where the microorganisms supsended in the wastewater can work more efficiently. These solids are handled separately from the supernatant which continues on to disinfection. After biological treatment.5 . Suspended growth process units include variations of activated sludge. and rotating biological contactors. Solids Handling Primary treatment and secondary biological processes concentrate waste organics into a sludge. Suspended Growth Processes In suspended growth processes. Conventional methods of TatyAlfiah/Minggu. or the water is agitated sufficiently to allow oxygen transfer. Methods for processing raw sludge include anaerobic digestion and mechanical dewatering by either belt-filter pressing or centrifugation. In the aeration tank. wastewater is vigorously mixed with air and microorganisms acclimated to the wastewater in a suspension for several hours. This allows the bacteria and other microorganisms to break down the organic matter in the wastewater. biotowers.Attached growth process units include trickling filters. oxidation ditches and sequencing batch reactors. 22 September 2013 Hlm . the microbial growth is suspended in an aerated water mixture where the air is pumped in. additional suspended solids.disposal are apllication as a fertilizer or soil conditioner on agricultural land.. individual treatment processes are necessary to remove nitrogen. refractory organics. phosphorus. As shown in Figure 3. However. advanced treatment processes are sometimes combined with primary or secondary treatment (e. Because advanced treatment usually follows high-rate secondary treatment. TatyAlfiah/Minggu. heavy metals and dissolved solids. chemical addition to primary clarifiers or aeration basins to remove phosphorus) or used in place of secondary treatment (e.g. overland flow treatment of primary effluent). 22 September 2013 Hlm .. it is sometimes referred to as tertiary treatment. or codisposal with municipal solid waste Tertiary and/or advanced treatment Tertiary and/or advanced wastewater treatment is employed when specific wastewater constituents which cannot be removed by secondary treatment must be removed.6 .g. landfilling in a dedicated disposal site. 22 September 2013 Hlm .TatyAlfiah/Minggu.7 . Selian itu juga tenaga yang diperlukan untuk mengoperasikan IPAL. apakah mengganggu. Tebutuhan area termasuk zona buffer. meliputi pertimbangan teoritis.8 . aspek lingkungan. konstruksi. Selain itu. Terdapat beberapa pertimbangan dalam menentukan diagram alir. operasional dan pemeliharaan. apakah dapat mengganggu ekosistem alami yang ada ? bagaimana kualitas dan kuantitas lumpur yang dihasilkan. 22 September 2013 Hlm . Mungkin diperlukan zona buffer. Diupayakan aliran secara grafitasi. Contoh-contoh diagram alir pengolahan limbah cair secara konventional (standard) adalah sebagai berikut : TatyAlfiah/Minggu. meminimalkan kebutuhan pompa yang akan menambah biaya. Oleh karena itu diperlukan perbandingan beberapa alternatif diagram alir kesesuaian fasilitas existing : sedapat mungkin pembangunan IPAL baru sesuai dengan system pengelolaan limbah yang telah ada di sekitarnya. misalnya jarak dengan lingkungan terbangun sekitar. diantaranya : karakteristik limbah – menentukan tingkat pengolahan limbah yang diperlukan dengan memperhatikan sumber limbah peraturan berlaku baik effluent standard maupun stream standard owner/pemilik IPAL : perlu memperhatikan kemampuan biaya desain. luasan lahan sebaiknya memungkinkan bila suatu saat diperlukan pengembangan IPAL. untuk mereduksi baud an bising. energi bhn kimia. Bagaimana rencana pembuangan maupun pemanfaatkannya – menjadi pertimbangan. memenuhi aspek estetika. Efluen IPAL akan dibuang dimana. area tersedia : menentukan profil hidrolik. penyimpanan sementara lumpur yang dihasilkan. serta permasalhan di lapangan topografi. meliputi OM:tenaga. baik operator maupun tenaga ahli pemilihan proses pengolahan . rencana disposal efluen maupun lumpur. aspek pembiayaan : sejak mulai konstruksi hingga OM. 22 September 2013 Hlm .TatyAlfiah/Minggu.9 . 10 . 22 September 2013 Hlm .TatyAlfiah/Minggu. 22 September 2013 Hlm .TatyAlfiah/Minggu.11 . 12 . 22 September 2013 Hlm .TatyAlfiah/Minggu. 22 September 2013 Hlm .13 .TatyAlfiah/Minggu. 14 . 22 September 2013 Hlm .TatyAlfiah/Minggu.