Pengaruh Laju Aliran Udara Terhadap Efisiensi Penyisihan Organik di dalam Air Lindi dengan Menggunakan Teknik Oksidasi Lanjut (O3/H2O2)

ABSTRACT Leachate has complex characteristics, and it is commonly processed biologically in the Leachate Treatment Plant (IPL) in Indonesia. However, as the landfill ages, the leachate becomes less biodegradable. An appropriate technique is needed to treat leachate at IPL, and one of the promising methods is advanced oxidation with O3/H2O2. This study examined the effect of air flow rate on the concentration of residual ozone (KSO) and its efficiency to remove organic compounds using the O3/H2O2 process. Leachate samples were collected as grab samples from TPA Sarimukti Bandung. As much as 1 L of leachate samples were placed in an ozone contactor equipped with a filter disc with a pore size of 100-160 µm. The dose of H2O2 was continuously added to 1.197 g/L. Compressor was used to provide airflow with variations of 2, 3, and 4 L/min. Dissolved Oxygen (DO) was measured to determine the concentration of residual ozone (KSO) and validated by examining KSO measurements with the Indigo colorimetric method. A strong relationship between KSO and DO (R2 = 0.99) was observed at an airflow rate of 4 L/min. The highest ozone mass transfer coefficient (KLa,O3) was recorded at a 4 L/minute flow rate with 0.0022 min-1 at 27 °C. The best removal efficiency has occurred at the fastest air flow rate (4 L/min) with COD, and UV254 removal was 88.89% and 14.87%, respectively. Keywords: DO, flow variation, KSO, leachate, O3/H2O2, organic, mass transfer ABSTRAK Karakteristik lindi sangatlah kompleks dan di Indonesia, Instalasi Pengolahan Lindi (IPL) pada umumnya menggunakan sistem pengolahan biologis. Namun demikian, seiring dengan pertambahan umur urugan sampah, lindi semakin tidak biodegradable. Teknik pengolahan tepat diperlukan untuk mengolah lindi di IPL. Salah satu teknik yang sering digunakan adalah oksidasi lanjut dengan O3/H2O2 dengan mentransferkan gas ozon ke dalam air lindi yang diukur sebagai Konsentrasi Sisa Ozon (KSO) dan menambahkan H2O2 untuk meningkatkan pembentukan OH? di dalam air. Penelitian ini bertujuan untuk mengetahui pengaruh laju aliran udara terhadap KSO serta pengaruhnya terhadap efisiensi penyisihan senyawa organik pada proses O3/H2O2. Sampel lindi diambil secara grab sampling dari TPA Sarimukti Bandung. Sebanyak 1 L sampel ditempatkan pada kontaktor ozon yang dilengkapi filter disc dengan pori berukuran 100-160µm. Dosis H2O2 yang diberikan tetap sebesar 1,197 g/L. Udara dialirkan dengan air compressor dengan variasi debit udara 2, 3, dan 4 L/menit. Pada penelitian ini, pengukuran Dissolved Oxygen (DO) digunakan sebagai pendekatan untuk mengukur KSO. Validasi dilakukan dengan meneliti hubungan antara KSO dan DO dan pengukuran KSO dilakukan dengan metode indigo colorimetric method. Hasil penelitian menunjukkan KSO dan DO memiliki hubungan yang kuat (R2 = 0,99) pada variasi aliran udara 4 L/menit. Laju aliran udara tercepat terjadi ketika nilai koefisien transfer masa ozon (KLa,O3) mencapai nilai tertinggi (0,0022 menit-1) pada suhu 27 oC. Hasil penelitian membuktikan efisiensi penyisihan COD (88,89%) dan UV254 (14,87%) tertinggi terjadi pada laju aliran udara tercepat selama 180 menit. Kata kunci: DO, aliran udara KSO, lindi, O3/H2O2, organik, transfer masa

Sampling concept for microplastics in combined sewage-affected freshwater and freshwater sediments

The pollution of the environment with microplastics is an issue of great concern, with research of this topic focusing on the sampling and analysis of microplastics. As the sampling method is connected to the matrices from which the samples are collected, there is no general method for the analysis of microplastics, neither in water nor in sediments and, especially, there is no existing method for combined sewage. To obtain comparable results of samples from different matrices, we present a concept based on samples taken from combined sewage, combined sewage-affected freshwater, and freshwater sediments, which were prepared analogously in a treatment process to establish an equivalent starting sample for further analysis. The concept is based on a filter disc (stainless-steel, 47- mm diameter, 20-μm mesh size) for sampling the different water and sediments. With this filter disc, the removal of organic and anorganic matrices was conducted and then used to generate subsamples of different size fractions, which are identical for all samples and complete the sampling concept.

Removal of Calcium Carbonate Water-Based Filter Cake Using a Green Biodegradable Acid

The filter cake is a very thin layer of solid particles deposited from the drilling fluid onto the surface of the drilled formation. This is essential during the drilling process as it reduces fluid filtrate invasion, contributing for the well’s integrity. When the drilling processes are over, this formation must be removed efficiently to allow for the primary cement jobs to be conducted efficiently, and for hydrocarbons to be produced without any restrictions. The removal process of the filter cake is challenging and requires specific techniques, depending on several factors including the filter cake homogeneity, drilling fluid components, weight of materials used, and the continuous phase of the drilling fluid (i.e., water or oil). This study evaluates the use of green biodegradable removal acid (GBRA) to dissolve calcium carbonate water-based filter cake. The removal efficiency of this new acid was analyzed using filtration and removal tests, conducted on a ceramic filter disc and real core samples at 212 °F. Then, the new formulation was subjected to physical properties measurements and biodegradation and corrosion tests. Furthermore, the performance of the new acid formulation was compared with 10 wt.% hydrochloric acid (HCl) to ensure its efficiency. The obtained results showed that the new acid formulation was effective at removing the filter cake, with a removal efficiency greater than 90%. The retained permeability was 100% and 94% with the ceramic filter disc and the real limestone core sample, respectively, confirming the good removal performance of the new acid formulation. The corrosion rate of GBRA (50 wt.%) at 212 °F was 0.032 lb/ft2, which was within the acceptable range according to oil industry practices (i.e., less than 0.05 lb/ft2 if the temperature is less than 250 °F), while HCl (10 wt.%) yielded a high corrosion rate of 0.68 lb/ft2.

An inorganic anionic polymer filter disc: direct crystallization of a layered silicate nanosheet on a glass fiber filter

Cation-exchangeable layered silicate nanosheet fine crystals covered thoroughly a commercially available silica fiber filter paper through hydrothermal reactions with LiF, MgCl2 and urea.

Study on Filtration Performance of Rotary Disc Filter with Different Filter Discs

Rotary disc filter is widely used in industrial water treatment. There are two methods to improving the filtration efficiency, which are the higher filtration velocity and lower filtration pressure drop; while the type of the filter disc plays an important role on the performance of filtration, In order to know how the filter disc affect performance of filtration, simplified model was used. On this basis, rectangular and triangular type was numerically simulated with the CFD software Fluent, DPM model, then the flow field configuration, velocity magnitude, pressure drop through the filter medium and the distribution of the particles were obtained. Then, the simulation results were analyzed and the conclusion was achieved that was under the same operation condition and porous parameters. Filter disc with a triangular type has greater advantages than the one with a rectangular type in the aspects of lower pressure drop, velocity distribution uniformity and particle distribution, which can highly improve the filtration efficiency.

Contaminants in Used Oils and Their Problems

Contaminants in hydraulic and lubricating oils are harmful to lubrication. Therefore, contamination control of hydraulic and lubricating oils has been implemented in many factories and oil cleanliness standards of hydraulic and lubricating oils have been established as criteria for oil contamination control. There are two types of oil cleanliness standards: one is based on particle count and the other on gravimetric analysis. NAS 1638, ISO 4406, SAE AS4059, and JISB9930 belong to the former and ASTM D4898 and JISB9931 to the latter. The par tide count defines oil cleanliness by counting the number of particulate contaminants in the certain size ranges, and the gravimetric analysis shows the weight of contaminants remaining, on a membrane filter disc after a certain quantity of oil was filtered under vacuum, the oil was washed out, and the membrane filter disc was completely dried. Recently, there is a ten dency that particle count dominates the technology to judge oil cleanliness. Of course, it is important to quantify the number of particulate contaminants in oils. However, all particles are not contaminants, as particles like graphite and MoS2, which are countable by particle count, are good additives for lubricants. Therefore, it is very important for us not only to judge oil cleanliness by the particle count but also to know without prejudice what they are. This article discusses some methods to separate contaminants, what contaminants are, and how much they are.