scholarly journals Studi Pendahuluan Pengolahan Air Payau Menjadi Air Bersih Dengan Metode Kombinasi Elektrokoagulasi Dan Adsorpsi Menggunakan Karbosil

2014 ◽  
Vol 2 (1) ◽  
pp. 1
Author(s):  
Eny Heriani R.N. ◽  
Wasinton Simanjuntak ◽  
Ilim .

This study was carried out to investigate treatment of brackish water using a combination of electrocoagulation and adsorption using carbosil prepared from rice husk with pyrolysis method. Electrocoagulation was applied with the aim to remove natural organic matter in the sample, using aluminim as electrodes, with the particular purpose to study the effect of potenstials.For this purpose, electrocoagulation experiments were conducted at potential of 4, 6, and 8 volt at fixed contact time of 60 minutes.The performance of the method was defined in term of absorbance reduction at the wavelengths of 254 and 285 nm, since the absorbance at these two wavelenghts was found to correlate well with the amount of organic matter in the water samples. The treated water was then subjected to adsorption process at different contac times of 5. 10, and 15 minutes, and the performance of the process was evaluated in term of electrical conductivity reduction.The results obtained indicate that for electrocoagulation process, the higest reduction of natural organic matter content was achieved using potential of 8 volt, and adsorption porcess of 15 minutes was found to result in reduction of electrical conductivity from 15.13 mS/cm to 10.10 mS/cm.Characterization of the carbosil using SEM/EDX technique revealed that the carbosil has practically homogeneous surface and able to adsorb salt and several other elements from the brackish water. Key words : adsorption, brackish water, carbosil, electrocoagulation

2014 ◽  
Vol 1 (1) ◽  
pp. 85
Author(s):  
Lenny Warlina ◽  
Ilim . ◽  
Wasinton Simanjuntak

This study was carried out to investigate treatment of hotel wastewater using a combination of electrocoagulation and adsorption using carbosil prepared from rice husk with pyrolysis method. Electrocoagulation was applied with the aim to remove natural organic matter in the sample, using aluminim as electrodes, with the particular purpose to study the effect of potentials.The treated water was then subjected to adsorption process at different contact times and the performance of the process was evaluated in term of the reduction of the absorbance at maximum wavelength.The performance of the method was defined in term of absorbance reduction at the maximum wavelength of 226 nm, which was determined by scanning the original sample at the wavelength ranging from 200 to 700 nm.According to literature, the maximum wavelength of 226 nm is commonly assigned to benzene structure, most likely from the Alkyl Benzene Sulfonate (ABS) used in detergents.The results obtained indicate that for electrocoagulation process, the highest reduction in the absorbance was achieved using potential of 10 volt.Adsorption process was found to result in the diminish of peak at 226 nm, reflecting that the organic pollutant associated with this wavelegth has been completely removed from the water.Characterization of the carbosil using SEMtechnique revealed that the carbosil has practically homogeneous surface morphology, supporting its ability to adsorb the pollutants from the wastewater. Key words : adsorption, carbosil, electrocoagulation, hotel wastewater


Agronomy ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 1567
Author(s):  
Haydee Peña ◽  
Heysa Mendoza ◽  
Fernando Diánez ◽  
Mila Santos

This work studies variables measured from the first phase of composting through the acquisition of the final product, with the goal of identifying those that are more strongly related to quality and are most useful for developing an index. The necessity to establish quality control procedures thus exists for the classification of raw materials in the same way as for the finished products. To accomplish this, three mixtures were prepared, with the goal of achieving a C/N ratio of 30 and a moisture content of 60%. The primary component of each mixture was: fruit processing waste (C1), sewage sludge from the food industry (C2), and the manufacturing waste of fried foods (C3). Temperatures were measured over 107 days, with the corresponding data fit to a logistical model where T °C ~ α / ((1 + exp (− (Time − β) / − γ))) + δ, with interaction compost * time being statistically significant (p < 0.001). This allowed for the temperatures, in keeping with health concerns, to be confirmed. Likewise, a linear regression analysis demonstrated the decomposition of organic matter at 0.82%/week. Statistically, the parameters, measured during the process, with the least variability were selected, which differed in the average contrasts: germination index (cucumber), electrical conductivity, and average moisture. A principal component analysis (PCA) and Spearman’s correlation analysis revealed the best Germination Index (GI) values for C1, due to lower electrical conductivity (EC) and bulk density (Bd) along with higher organic matter content (TOM). For its part, C2 induced a higher Relative emergence (RE) of the cucumber thanks to its higher content of total nitrogen (TN) and lower contribution of Cu, Zn and K. C3 showed a higher presence of salts, less favorable physical characteristics (>Bd and <TPS, total pore space) and higher content of Zn and Cu. Composting carried out with appropriate mixtures can offer high-quality products for use as fertiliser, in soil restoration, and as an alternative substrate to peat and virgin mountain soil.


2021 ◽  
pp. 197-204
Author(s):  
Modi Ahmed ◽  
Khaliq Beg

Abstract Brunauer, Emmett, and Teller (BET) test were applied to dust samples in which samples (BET) surface area is highly related to the roundness of dust particles. The higher angularity and low roundness of the dust particles show a higher (BET) surface area. The roundness is also related to the particlesize distribution and mineralogical composition. The electrical conductivity test relates very well with the chemical and physical properties of dust samples in the transmission of an electrical current. The organic matter content was measured using the ignition method and the pH of the samples was recorded. Maps of the distribution of high and low BET concentrations, electrical conductivity EC, organic matter content, pH.


2015 ◽  
Vol 2 (1) ◽  
pp. 17-25
Author(s):  
Mohammad Kamrul Hasan ◽  
Md Bayeazid Mamun

The study was conducted in Dukhula sadar and Gasabari forest range under Madhupur Sal Forest of Bangladesh to determine the soil nutrient composition and isolation of fungi with varying stands. Three stands viz. pure sal, plantation and mixed were considered as treatment of the study. A quadrate sample plot of 10×10 m2 size was measured to collect soil samples for both chemical analysis and fungi isolation. Soil pH, electrical conductivity, organic matter content, total N, available P, exchangeable K, available S, fungal abundance and colony character (cm) were determined to achieve the objective of the study. The results revealed that soil pH and electrical conductivity were highest (6.61 and 21.10?S/cm) in mixed stand and lowest (6.38 and 10.75?S/cm) in pure stand. Organic matter content and total N were highest (2.24 and 0.145%) in plantation stand and lowest (1.65 and 0.112%) in mixed and pure stand, respectively. Available P, exchangeable K and available S were highest (3.65, 98.66 and 17.53ppm) in pure stand and lowest (1.97, 79.49 and 10.25ppm) in plantation stand. In addition, four fungal genera Sclerotium, Rhizoctonia, Pythium and Verticillium were identified in the study area soils. The highest fungal population (entire genus except Verticillium) (colony number/g soil) was found in mixed stand while it was found lowest in pure (Sclerotium ) and plantation stand (Rhizoctonia and Pythium ). There was no significant variation in colony diameter of the fungi among the treatments. Therefore, it can be concluded that better soil health was maintained in natural forest rather than plantation forest.Res. Agric., Livest. Fish.2(1): 17-25, April 2015


2019 ◽  
Vol 49 (1 y 2) ◽  
pp. 19-28
Author(s):  
Víctor Manuel Montoya-Jasso ◽  
Gerardo Sergio Benedicto Valdés ◽  
Víctor Manuel Ordaz Chaparro ◽  
Alejandrina Ruiz-Bello ◽  
Jesús Manuel Arreola Tostado ◽  
...  

The objective was to evaluate the mineralization of two mixtures of substrates with different nitrogen content, moisture, compost and mineral mixture based on zeolite and dolomite. The measured parameters were pH (extract 1:2), electrical conductivity (extract 1:5) by conductimeter; content of organic matter by ignition; organic carbon based on the results of organic matter using the Douglas factor= 0.5; and nitrogen per micro Kjeldahl. The flow of CO2 was measured with the IRGA gas analyzer. For both moisture content, the compost-free substrates had a higher C/N ratio. Compost substrates, because of their high mineralization, were appropriate with advantages to the supply of nitrogen. Substrates with compost and 15% moisture released higher CO2 by presenting more easily degradable compounds. Mineralization rates on substrates were higher with 15% humidity due to increased porous space occupied by gases, in addition, the supply of 50% of nitrogen had a low immobilization due to the lower organic matter content and the 40 cm3 L-1 mineral mixture content changed the dilution of carbon to be metabolized by microorganisms. The rate of mineralization was affected by the use of minerals, the quality and the subtrate origin


2013 ◽  
Vol 10 (4) ◽  
pp. 323 ◽  
Author(s):  
David Kocman ◽  
Scott C. Brooks ◽  
Carrie L. Miller ◽  
Xiangping L. Yin

Environmental context Although mercury associated with colloids is an important part of the aquatic Hg cycle, there is currently no fast and reliable method to separate complexes smaller than traditional filter pore sizes. We test commercially available centrifugal ultrafilters for their applicability to size fractionation of total Hg and methylmercury in freshwaters. Sorption of Hg onto the filters precludes their use for fractionation of inorganic Hg, the approach proved to be very suitable for methylmercury fractionation regardless of sample organic matter content. Abstract Amicon Ultra-15 centrifugal filters with nominal molecular weight cut-offs of 100, 30 and 3kDa, were tested for separating Hg complexes in freshwaters. Experiments used Hg-contaminated water from East Fork Poplar Creek (EFPC) and laboratory-prepared Hg solutions containing Suwannee River natural organic matter (SR-NOM). Investigations focussed on Hg and dissolved organic carbon blank levels, Hg sorption and leaching, Hg mass balance closure and spike recoveries of inorganic and methylmercury (MeHg). Hg spike recoveries for EFPC samples were low (57±16%, n=30) due to sorption. MeHg recovery averaged 87±9% (n=15) suggesting it was less affected by sorptive losses. SR-NOM samples yielded similar dissolved organic matter (DOM) and MeHg size fractionation patterns with ~20% of the MeHg found in the less than 3-kDa fraction. Overall, the distribution of MeHg followed a pattern similar to the DOM, indicating the importance of both sample DOM quantity and quality for MeHg partitioning in aquatic systems. Although the use of these ultrafilters for inorganic Hg in freshwater samples is not recommended, they were successfully used for MeHg in EFPC where the majority of MeHg was found to be either dissolved or associated with phases smaller than 3kDa.


2009 ◽  
Vol 9 (2) ◽  
pp. 173-180 ◽  
Author(s):  
I. García ◽  
L. Moreno

Filtration with granular activated carbon (GAC) after an enhanced coagulation (EC) process was evaluated in order to determine the effectiveness of GAC in the reduction of natural organic matter (NOM), which should result in much lower formation of trihalomethane in the disinfection step. The results show that a combination of EC and GAC considerably reduces the organic matter content, which is mainly fulvic acid. This type of organic matter is removed with high coagulant dosages which neutralize their high anionic charge. A further reduction of NOM is achieved due the adsorption of NOM by GAC. As a result, the average trihalomethane (THM) concentration was only 14.5±5 μg L−1. Enhanced coagulation alone decreased the NOM concentration by 50%, but the remaining NOM reacted in the chlorination step and a higher average THM concentration was found (38±23 μg L−1). An average THM concentration of 73.8±41.2 μg L−1 was found at the drinking water plant of Boaco when conventional treatment was used. This THM concentration sometimes exceeds the maximum contaminant level of 80 μg L−1 established by the United States Environmental Protection Agency (USEPA), but not the Nicaraguan threshold of 460 μg L−1.


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