Distribution of Bound and Free Water in Anatomical Fractions of Pine Residues and Corn Stover as a Function of Biological Degradation

2021 ◽  
Author(s):  
Ling Ding ◽  
Josephine N. Gruber ◽  
Allison E. Ray ◽  
Bryon S. Donohoe ◽  
Chenlin Li
Keyword(s):  
Corn Stover ◽  
Free Water ◽  
Biological Degradation

Microwave resonance method for measuring microliter volumes of free moisture in aviation fuels

2020 ◽  
pp. 49-56
Author(s):  
Vitaly V. Volkov ◽  
Michael A. Suslin ◽  
Jamil U. Dumbolov
Keyword(s):  
Solid Surface ◽  
Free Water ◽  
Resonance Method ◽  
Cavity Resonator ◽  
Maximum Error ◽  
Aviation Fuel ◽  
Fuel Quality ◽  
Microwave Resonance ◽  
Free Moisture ◽  
Microwave Losses

One of the conditions for ensuring the safety of air transport operation is the quality of aviation fuel refueled in aircraft. Fuel quality control is a multi-parameter task that includes monitoring the free moisture content. Regulatory documents establish the content of free water no more than 0.0015% by weight. It is developed a direct electrometric microwave resonance method for controlling free moisture in aviation fuels, which consists in changing the shape of the water drops by pressing them on a solid surface inside a cylindrical cavity resonator. This can dramatically increase dielectric losses. Analytical and experimental analysis of the proposed method is carried out. The control range from 0,5 to 30 μl of absolute volume of moisture in aviation fuels with a maximum error of not morethan 25 % is justified. The sensitivity of the proposed method for monitoring microwave losses in free moisture drops transformed into a thin layer by pressing is an order of magnitude greater than the sensitivity of the method for monitoring microwave losses in moisture drops on a solid surface in a resonator. The proposed method can be used as a basis for the development of devices for monitoring the free moisture of aviation fuels in the conditions of the airfield and laboratory. The direction of development of the method is shown.

EFEKTIVITAS TANAMAN GENJER DALAM MENURUNKAN BOD DAN COD LIMBAH CAIR TAHU HASIL PROSES ANAEROB

2016 ◽  
Vol 4 (1) ◽  
Author(s):  
Muhammad Irvan Nurliansyah
Keyword(s):  
Water Surface ◽  
Free Water ◽  
Surface Flow ◽  
Free Water Surface

ABSTRAK Limbah cair tahu merupakan limbah cair yang berasal dari proses pembuatan tahu. Limbah cair tahu mengandung senyawa organik yang tinggi. Pembuangan limbah cair tahu secara langsung ke badan air tanpa dilakukan pengolahan dapat mempengaruhi dan mencemari lingkungan. Suatu cara untuk menanggulangi permasalahan tersebut adalah melakukan pengolahan limbah cair tahu. Salah satu alternatif pengolahan limbah cair tahu yang dapat digunakan adalah fitoremediasi menggunakan tanaman genjer. Penelitian ini bertujuan untuk mengetahui efisiensi pengolahan dan efektivitas waktu tinggal pengolahan limbah cair tahu menggunakan tanaman genjer dalam menurunkan BOD dan COD effluen hasil proses pengolahan anaerob limbah cair tahu. Metode yang digunakan dalam penelitian ini adalah fitoremediasi menggunakan tanaman genjer pada sistem lahan basah buatan Free Water Surface flow dengan waktu tinggal 3 hari, 5 hari dan 7 hari. Hasil penelitian menunjukkan bahwa efisiensi pengolahan secara fitoremediasi pada hari ke 3 untuk BOD dan COD berturut-turut sebesar 21,28% dan 16,13%. Pada hari ke 5 efisiensi pengolahan yang diperoleh untuk BOD dan COD berturut-turut sebesar 52,60% dan 45,93% sedangkan efisiensi pengolahan pada hari ke 7 untuk BOD dan COD berturut-turut sebesar 76,42% dan 70,74%. Waktu tinggal efektif yang diperoleh pada penelitian ini adalah  7 hari dengan nilai BOD dan COD telah berada dibawah baku mutu yaitu berturut-turut sebesar 72,72 mg/l dan 213,33 mg/l.   Kata kunci : limbah cair tahu, fitoremediasi, tanaman genjer, efisiensi pengolahan, waktu tinggal

Environmental significance of atrazine in aqueous systems and its removal by biological processes: an overview

2013 ◽  
Vol 8 (2) ◽  
pp. 159-178 ◽  
Keyword(s):  
Drinking Water ◽  
Ground Water ◽  
Water Environment ◽  
Biological Processes ◽  
Biological Degradation ◽  
Environmental Significance ◽  
Carbon And Nitrogen ◽  
Carbon Nitrogen Ratio ◽  
Nitrogen Ratio ◽  
Living Organisms

Atrazine, a chlorinated s-triazine group of herbicide is one of the most widely used pesticides in the World. Due to its extensive use, long half-life and various toxic properties, it has very high environmental significance. Up to 22 mg l-1 of atrazine was found in ground water whereas permissible limit of atrazine is in ppb level in drinking water. As per Indian standard there should not be any pesticide present in drinking water. Among many other treatment processes available, Incineration, adsorption, chemical treatment, phytoremediation and biodegradation are the most commonly used ones. Biological degradation of atrazine depends upon various factors like the operating environment, external carbon and nitrogen sources, carbon/ nitrogen ratio (C/N), water content and the bacterial strain. Although, general atrazine degradation pathways are available, the specific pathways in specific conditions are not yet clearly defined. In this paper extensive review has been made on the occurrence of atrazine in surface and ground water bodies, probable sources and causes of its occurrence in water environment, the toxicity of atrazine on various living organisms and its removal by biological processes.

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