Papers by Keyword: CEC

Abstract: Nanoparticles of Merapi volcanic ash and phosphate-solubilizing fungi were expected to function as ameliorants in improving some Inceptisols characteristics. Nanoparticles of volcanic ash were used in accelerating and streamlining the chemical reaction in the soil. Phosphate-solubilizing fungi were expected to assist the process of several soil reactions. The aim of the research was to improve some chemical characteristics like available P, cation exchange capacity, Fe, and Zn content of Inceptisols in Cilembu Village, Sumedang District, West Java Province, Indonesia. The research used a complete randomized experimental design in factorial with two factors. The first factor was the nanoparticle of Merapi volcanic ash consisted of four doses on soil weight percentage (0%, 2%, 4%, and 6%). The second factor was phosphate-solubilizing fungi consisted of two doses (without and 10 g.kg^-1). The volcanic ash was collected from Mt. Merapi, Central Java, after the eruption of November 2010 and kept in the Laboratory of Soil Physics and Conservation in Faculty of Agriculture, Universitas Padjadjaran. The nanoparticle of volcanic ash was processed at Nanotechnology and Graphene Research Centre, Universitas Padjadjaran. The phosphate-solubilizing fungi were isolated from Inceptisols in Soil Microbiology Laboratory, Universitas Padjadjaran. These treatments were combined and mixed with soils and incubated for three months. Every one month during those three months of the incubation period, some soils were taken to be analyzed of available P, cation exchange capacity (CEC), available Fe, and available Zn. The result showed that there was no interaction between the nanoparticle of Merapi volcanic ash and phosphate-solubilizing fungi to parameters investigated except the CEC after two months of incubation. There was an effect of nanoparticle volcanic ash and phosphate-solubilizing fungi individually to available Fe dan Zn. There was a trend of increasing available P, and CEC and decreasing available Fe and Zn by the longer period of incubation.

Abstract: Four soil samples different in there CaCO₃ forms contents (total, active and active /total CaCO₃) were taken from tillage horizon 0-30 cm depth to study the impacts of CaCO₃ form on some soil inherent quality indicators in calcareous soils. Result revealed that the total CaCO₃ forms have a great influence on particle size distribution to make it coarser in general comparing with the absence of CaCO₃ with soil particles. The increase of active /total (A/T CaCO₃%) till 50% has a positive effect on increasing soil electrical conductivity E.C ds.m-1, while increment of A/T CaCO₃ over 50% till 70% detrimentally reduced soil E.C ds.m-1 hundred fold. The elevation of (A/T CaCO₃%) has inverse correlation with soil cation exchange capacity (CEC Cmole.kg soil). the elevation of (A/T CaCO₃%) has inverse correlation with soil cation exchange capacity (CEC Cmole.kg soil) the (A/T CaCO₃%) ratio over 56% till 69% significantly improves the mean weight diameter and macro aggregate. In general the optimum total CaCO₃ for micro aggregate formation may not exceed 20%. The best Total and (A/T CaCO₃%) for better aggregate stability is between 20 to 48% . The proper total calcium carbonate for better total heterotrophic aerobic bacterial activity is around 20% . The best growth of the Azotobacter species which is belonging to non-symbiotic nitrogen fixing bacteria is obtained when total CaCO₃ ranges between 10-20% or between 48-56% of (A/T CaCO₃%).

Abstract: The clays of the smectite group, mainly montmorillonite, are widely used in the production of organoclays due to the small dimensions of the crystals, high cation exchange capacity (CEC), and swelling capacity in water, which lead to a rapid and efficient intercalation of organic compounds used in the synthesis. In this context, this research was intended to make a comparative study of clays organofilized with ionic surfactants through their respective CEC. We selected four samples of bentonites, namely Chocolate (Boa Vista, PB), Brasgel (industrial), Dark Bentonite (Pedra Lavrada, PB) and M400 Bentonite (industrial). The natural samples were characterized through XRD, EDX, TA and GA, and the organofilized ones through XRD. The characterization tests showed that the samples are composed of clay minerals of the smectite group, the CEC values ​​were insignificant changes when comparing the values ​​of natural and activated clays with sodium carbonate. And the levels indicated by the CEC for the ionic surfactant Praepagem HY proved insufficient to transform the organophilic clays, as the nominees for the ionic surfactant Praepagem WB led to adequate results regarding the incorporation of the surfactant in the clay fraction of the studied samples.

Abstract: The structure of sericite is stable, and it is hard to prepare polymer layered silicate nanocomposites (PLSN). Therefore, structural modification was employed to activate sericite to reduce the layer charger. The thermal treated sericite (S₁) was prepared by thermal modification at 800 for one hour. Then, the resulting product was modified with sodium fluorosilicate, whose effect was characterized by X-ray diffraction (XRD) analysis. The dissolving-out amount of Al³⁺ of salt-treated product (S₂) reached circa 2.55 mg/g at the optimal processing conditions. CEC of S₂ was increased to 10.52 meq/100g compared with that of original sericite (4.94 meq/100g). The results of XRD analysis indicated that mica-type phase persisted after salt modification with sodium fluosilicate.

Abstract: This study is about the development of porous material which shapes Ø3~8mm bead with sewage sludge by molten-salt method. The development of porous material was conducted by 2 different processes. One is made by molding sewage sludge into beads with pelletizer and then coating the beads with molten-salt and lastly sintered at 1050°C, and the other is mixing sewage sludge with molten-salt which is using synthesized zeolite, and then molding the mixture into beads with pelletizer. The molded mixture is finally sintered at 1050°C. We evaluated the value of developed material as sorbent and artificial soil for tree-planning by analyzing surface area, distribution of pore size, and cation exchange capacity(CEC). According to the results, surface coated porous material have 92.8m2/g of surface area and CEC 98.9meq/100g and the mixture sewage sludge with molten-salt have 104.1m2/g of surface area and CEC 140.8meq/100g. Thus, developed porous material can be applied to various uses as sorbent and artificial soil.

Abstract: The object of this study is to prepare adsorbents to remove heavy metals from abandoned mine residues. There are many factors that affect the adsorptivity of prepared adsorbents. The adsorptivity of prepared adsorbents is evaluated by cation exchange capatity(CEC). The maxium CEC value is obtained by Dongwon mine residues treated with NaOH. The optimum condition at that time is 75/25 wt% of mixing ratio of Dongwon mine residues and NaOH under N2 atmosphere at the activation temperature of 500°C. The CEC value was 95meq/100g at this condition. 99.5% of Pb was removed under the condition of 50 mg/L, pH 5 and reaction time of 1hr.