Reaksi Analisa Sulfida dengan Titrasi Iodometri

Metode iodometri ini tidak membedakan bentuk ion sulfida dalam larutan. Sulfida direaksikan dengan iodium berlebih dalam suasana asam, dan iodium yang tersisa kemudian ditentukan oleh titrasi dengan natrium tiosulfat, menggunakan starch sebagai indikator (Kolthoff and others,1969)

Sulfida

Daftar Pustaka

http://www.caslab.com/Test-Methods-Search/PDF/USGS-Method-I-3840.pdf

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What happens to total petroleum hydrocarbons (TPH) when they enter the environment

  • TPH may enter the environment through accidents, from industrial releases, or as byproducts from commercial or private uses.
  • TPH may be released directly into water through spills or leaks.
  • Some TPH fractions will float on the water and form surface films.
  • Other TPH fractions will sink to the bottom sediments.
  • Bacteria and microorganisms in the water may break down some of the TPH fractions.
  • Some TPH fractions will move into the soil where they may stay for a long time.

Reference

http://www.atsdr.cdc.gov/toxfaqs/tf.asp?id=423&tid=75

Impurities (Zat yang tidak disukai) dalam Minyak Bumi

  • Air

Apabila kandungan air lebih besar dari 0,5 % dalam proses pengolahan dapat menimbulkan tekanan dalam jumlah besar, hal ini akan membahayakan keselamatan operasi kilang.

Cara Pencegahan

–          Dengan cara didrain yang dilakukan dilapangan Produksi atau pun di Kilang

–          Apabila dalam bentuk emulsi harus dipisahkan dengan cara memberikan bahan kimia : deemulsifier

  • Garam

Kandungan garam berupa NaCl dan MgCl2 dalam proses dapat menimbulkan karat akibatnya dapat merusak peralatan

Cara Pencegahan

–          Yang terlarut dalam air dapat dibersihkan dengan cara didrain.

–          Bentuk emulsi (MgCl2), dalam proses dapat diinjeksikan NH3 pada puncak Kolom Fraksinasi

  • Belerang (S)

Kandungan belerang dalam proses dapat menimbulkan karat pada peralatan proses maupun pada tanki penimbun.

Cara Pencegahan

–          Dalam jumlah besar dapat dilakukan cara proses desulfurisasi

–          Produknya (gasoline/naphtha) dicuci dengan soda api (NaOH) atau proses Hydrotreating

Selain di atas masih ada beberapa impurities lain seperti nitrogen, oksigen, logam (contohnya vanadium, nikel) dll. Biasanya dalam minyak bumi impurities tersebut kadarnya tidak terlalu besar terutama untuk minyak bumi yang dihasilkan di sumatera, Kalimantan dan jawa. Sedangkan minyak bumi yang dihasilkan dari Indonesia timur seperti Irian biasanya kadar impuritiesnya besar. Sehingga dibutuhkan treatment sebelum proses pengolahan dan produknya dilakukan proses hydrotreating terlebih dahulu untuk spesifikasi bahan bakar minyak.

Daftar Pustaka

Modul Pelatihan Introduksi Migas Hulu dan Hilir Proses Pengolahan Migas Disusun Oleh Winarno ST. Pusdiklat Migas Cepu

Sources of Water Impurities

A water impurity is any substance other than water that found in the water sample, whether harmful or beneficial.

For example, Total Petroleum Hydrocarbon (TPH) is a water quality that result mainly from the release of petroleum products into the household well . This parameter is unregulated impurities (Permenkes No 492 Tahun 2010) but this analysis is useful in case of pollution problems

Impurities can be divided into three classes :
1. Regulated impurities (pollutants) considered harmful or aesthetically objectionable
2. Unregulated impurities not considered harmful
3. Unregulated impurities not yet evaluated for their potential health risks

In water quality analysis, unregulated as well as regulated impurities may be measured

A. Natural Sources
Snow and rainwater contain dissolved and particulate minerals collected from atmospheric particulate matter and a small amount gases dissolved from atmospheric gases. Snow and rainwater have virtually no bacterial content until they reach the surface of the earth.
After precipitation reaches the surface of the earth and flows over and through the soil, there are innumerable opportunities for introduction of mineral, organic, and biological substances into water. Water can dissolve at least a little of nearly anything it contacts from the atmosphere and soil. Because of its relatively high density, water can also transport suspended solid. Even under pristine conditions, surface and ground-water will usually contain various dissolved and suspended chemical substances.

B. Human-Caused Sources
Many human activities cause additional possibilities for water contamination. Some important sources are :
– Construction and mining
– Industrial waste
– Petroleum leaks and spill
– Agricultural application
– Urban storm water runoff
– Effluents from industries and waste treatment plant
– Leachate from landfill, septic tanks, treatment lagoons and mine tailing
– Fallout from atmospheric pollution

Reference

Eugene R. Weiner. Application of Environmental Aquatic Chemistry. A Practical Guide. Third edition. CRC Press

Komponen Dasar Kerangka Pemodelan

Lagi baca buku untuk bikin tulisan pemodelan dan ketemu dengan komponen dasar kerangka pemodelan sbb

Pemodelan

Lumayan sulit yach tapi masih bisa dipelajari kok :-). SEMANGAT !!!!

Dafta Pustaka

Robert V. Thomann, John A. Mueller. Principles of Surface Water Quality Modeling and Control. Harper Collins Publishers. 1987