PROSES PENGOLAHAN AIR LIMBAH

Apakah Target Pengolahan air limbah ?? Pengurangan bahan tersuspensi dan terapung Pengurangan bahan organik (BOD,COD) Pengurangan kandungan bahan anorganik dan logam berat Pengurangan kandungan nutrient (N dan P) Penghilangan mikroorganisme patogen. Pengurangan minyak dan lemak.

TARGET PENGOLAHAN AIR LIMBAH PENGOLAHAN AIR LIMBAH UNTUK MENGHILANGKAN BAHAN PENCEMAR BERSENYAWA ORGANIK MAUPUN AN-ORGANIK

Macam Proses Pengolahan Secara fisik: Pengolahan secara kimiawi pengolahan dengan menggunakan gaya atau kerja secara fisik yang meliputi : pengendapan, penyaringan, pengadukan, flokulasi, pengapungan, filtrasi. Pengolahan secara kimiawi pengolahan dengan penambahan bahan kimia atau melalui reaksi-reaksi kimiawi antara lain : Presipitasi (koagulasi-flokulasi), adsorpsi, pertukaran ion dan disinfeksi.

3. Pengolahan secara biologis: Metoda pengolahan biologis secara aerobik bertujuan untuk mengkonversikan senyawa organik yang terlarut, tersuspensi dan koloid dalam air limbah menjadi sel – sel mikroorganisme baru yang berkoloni membentuk biofloc sehingga dapat dipisahkan melalui proses pengendapan

Tahapan Pengolahan Pengolahan tahap pertama (Primary Treatment): umumnya pengolahan secara fisik. Pengolahan tahap kedua (Secondary Treatment): berupa pengolahan fisik – kimia dan atau biologis Pengolahan tahap ketiga (Tertiary Treatment, advanced treatment): umumnya untuk mereduksi kandungan nutrien, pestisida atau logam-logam yang masih terkandung di dalamnya.

URAIAN PROSES PROSES KETERANGAN FISIK/MEKANIK Proses untuk menghilangkan benda kasar/sampah dan partikel kasar  screening, grit chamber, bak pengendap, filtrasi FISIK-KIMIA Proses untuk menghilangkan partikel tersuspensi menggunakan bahan kimia dan pengadukan  koagulasi-flokulasi-sedimentasi, presipitasi BIOLOGIS Proses untuk menghilangkan pencemar organik yang biodegradable menggunakan mikroorganisme  activated sludge (conventional & extended), biofilter (trickling filter), RBC, lagoon, stabilization pond. Proses biologis dapat bersifat aerobic maupun anaerobic PENGOLAHAN LANJUT Proses untuk menghilangkan bahan pencemar yang lebih sulit dihilangkan dengan cara biasa. Pengolahan lanjut dapat menggunakan proses fisik-kimia maupun biologis  nitrifikasi-denitrifikasi, adsorpsi, stripping, presipitasi, mikrifiltrasi, ion exchange, koagulasi-flokulasi 12/04/2018

TEKNOLOGI PENGOLAHAN AIR LIMBAH Bahan pencemar Sistem pengolahan 1 Padatan tersuspensi Penyaringan kasar Pengendapan Filtrasi Koagulasi/Sedimentasi Natural system (land treatment) 2 Organik Activated sludge Biofilter Aerated lagoon Natural system 3 Pathogen Chlorinasi Ozonasi Radiasi UV 4 Nutrient – Nitrogen Nitrifikasi-denitrifikasi Ammonia stripping Pertukaran ion 5 Nutrient - Fosfor Presipitasi Pengolahan biologis Pengolahan biologis-kimiawi 12/04/2018

PEMILIHAN TEKNOLOGI PENGOLAHAN AIR LIMBAH Faktor yang berpengaruh: karakteristik air limbah kualitas efluen yang diharapkan Kompleksitas pengolahan Biaya investasi dan O-M 12/04/2018

METODE PENGOLAHAN “BIODEGRADABLE ORGANIC DISSOLVED POLLUTANT” PROSES FISIK – KIMIA PROSES BIOKONVERSI AEROBIK DAN AN-AEROBIK: POLA PERTUMBUHAN TERSUSPENSI : SISTIM LUMPUR AKTIF : TANKI AERASI; OXYDATION DITCH. KOLAM AERASI DAN KOLAM STABILISASI POLA PERTUMBUHAN TERLEKAT : BIOFILTER ROTATING BIOLOGICAL CONTACTOR (RBC)

PENGOLAHAN SEDERHANA SASARAN: untuk limbah industri berpotensi pencemaran rendah BENTUK: tangki pengendapan 12/04/2018

PENGOLAHAN MENENGAH SASARAN: untuk limbah industri berpotensi pencemaran sedang BENTUK: tangki pengendapan + pengolahan biologis sederhana / fisik-kimia 12/04/2018

12/04/2018

PENGOLAHAN KOMPLEKS SASARAN: untuk limbah industri berpotensi pencemaran tinggi BENTUK: pengolahan fisik + fisik-kimia + biologis + pengolahan lanjutan + pengolahan lumpur 12/04/2018

PENGOLAHAN KOMPLEKS anaerobik bioreaktor settling tank 1 Aerobik Bioreator settling tank 2 holding tank Pengolahan lanjut Treated Water 12/04/2018

Diagram Alir

PROSES FISIK

Screens The removal of large objects that may damage pumps or block channels Fixed or mechanical Velocity in channels about 0.3 - 0.4 m/s Design for PWWF All screenings to be removed/buried Location of strong odour from decomposition

Mechanical bar screen

Rotating drum screen

Comminutors These are mechanical cutting screens that reduce the size of large objects Shredded matter are returned to the flow stream A by-pass may be included

Comminutor

Grit Chambers Purpose is to remove inorganic grit/sand 0.2 - 1 mm size through differential settling Aim is to prevent damage to pumps, blockage of channels and cementing of sludge in settling tanks Two types of grit chambers, namely constantly velocity and aerated/spiral flow tanks

Constant Velocity Grit Chamber Class I settling - horizontal flow Uniform velocity at 0.25 - 0.35 m/s Ideal parabolic shape or approximation Width:depth ratio 1:1 Length  18 x max. depth

Constant Velocity Grit Chamber

Aerated or Spiral Flow Grit Chamber Flexibility of control; more efficient grit removal and can assist pre-aeration Air supply or spiral flow controls the amount of silt removed Suitable for larger population > 10 000 ep HRT of about 3 min at PWWF

Aerated or Spiral Flow Grit Chamber

Vortex Flow Grit Chamber

Primary Sedimentation Solids separation by gravity Aim is to remove gross suspended solids (organic matter) Largely class II settling of flocculent matter and natural coalescence or flocculation occurs Surface skimmers remove floating matter (scum, grease etc) The settled solids are pumped to an anaerobic digestion tank. The effluent (settled sewage) from primary treatment flows to the next stage ie. secondary treatment

Some Features of Primary Settling Design to accept 2 to 3 x ADWF Removal of 40 - 75% suspended solids Some incidental BOD5 reduction 25 - 40% Hydraulic loading Q/A  30 m3/m2.d Hydraulic retention time (HRT) 1.5 to 3 h; depth 2.5 to 5 m Also act as flow/strength equalisation basins Sludge scrapers should not cause re-suspension

Primary settling % removed vs time

Types of Primary Settling tanks Rectangular horizontal-flow Tanks use less space Forward velocity 10 - 15 mm/s Weir loading rate < 300 m3/m.d Length:width ratio 3:1

Rectangular horizontal-flow

Types of Primary Settling tanks Up-flow tank Square with 60o sludge hopper No moving parts as sludge is removed hydrostatically Some possible particle carry over

Up-flow settling tank

Types of Primary Settling tanks Circular radial flow tank Inflow to a central stilling box Radial-horizontal flow Uses radial scrapers to remove sludge

Circular Radial Flow Tank

Circular Radial Flow Tank

PROSES BIOLOGIS

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SUSPENDED MICROORGANISM ATTACHED MICROORGANISM B I C P S SUSPENDED MICROORGANISM GROWTH ACTIVATED SLUDGE (CSTR) EXTENDED AERATION 3. SEQUENCING BATCH REACTOR 4. OXYDATION DITCH 5. AERATED LAGOON ATTACHED MICROORGANISM GROWTH TRICKLING FILTER ROTATING BIOLOGICAL CONTACTOR 12/04/2018

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MODEL PROSES LUMPUR AKTIF

SETTLING TANK AERATION TANK

Oxydation Ditch

Kolam Stabilisasi 12/04/2018

Kolam Fakultatif 12/04/2018

“TRICKLING FILTER” “Proses pengolahan biologis dengan prinsip pemanfaatan mikroba dengan pertumbuhan terlekat pada suatu media”. Unsur Pencemar yang dihilangkan : BOD, Nitrogen – amonia,dan zat padat tersuspensi. Komponen penting : Biofilm Media Distributor air limbah Ventilator udara Desludging Tangki pemisah lumpur

Trickling Filter 12/04/2018

Jenis – Jenis Media: Batu Kali Keramik Plastik Kayu Ukuran: Diameter rata-rata: 2 – 10 cm

Rotating Biological Contactor (RBC) 12/04/2018

PENGOLAHAN SECARA ALAMIAH

PROSES BIODEGRADASI SECARA ALAMIAH

PENYARINGAN PENGENDAPAN BIODEGRADASI

WET LAND

SEPTIC TANK