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Search Results: 1 - 10 of 885 matches for " Carbonate Alkalinity "
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A New Approach to Carbonate Alkalinity  [PDF]
Bogus?aw Pilarski, Anna M. Micha?owska-Kaczmarczyk, Agustin G. Asuero, Agnieszka Dobkowska, Monika Lewandowska, Tadeusz Micha?owski
Journal of Analytical Sciences, Methods and Instrumentation (JASMI) , 2014, DOI: 10.4236/jasmi.2014.42009

The article provides experimental data applied to the determination of carbonate alkalinity (CAM) according to modified Gran II functions. CAM is related to the mixtures NaHCO3 + Na2CO3 and Na2CO3 + NaOH. In addition to the determination of equivalence volumes, one of the main novelties of the proposed method is the possibility of determining the activity coefficient of hydrogen ions (γ). Moreover, CAM can be used to calculate the dissociation constants (K1, K2) for carbonic acid and the ionic product of water (KW) from a single pH titration curve. The parameters of the related functions are calculated according to the least squares method.

Estimativa de carbonato de cálcio aplicado via água de irriga??o nas regi?es da Chapada do Apodi e Baixo A?u, RN
Maia, Celsemy E.;Morais, Elis R.C. de;Oliveira, Maurício de;
Revista Brasileira de Engenharia Agrícola e Ambiental , 2001, DOI: 10.1590/S1415-43662001000100013
Abstract: the application of irrigation water with high contents of carbonate and bicarbonate can contribute to ph elevation of the soils after some years of cultivation. this study had as its objective the evaluation of the irrigation water with respect to its carbonate and bicarbonate content, based on the concept of the equivalent calcium carbonate (ecaco3) in the region of the chapada do apodi and baixo a?u in the state of rio grande do norte, brazil. considering an irrigation water depth of 400 mm, the results showed that the waters of the region of the chapada do apodi presented larger values of ecaco3 compared to those of the region of baixo a?u. in the region of the chapada do apodi, independent of the origin, largest values of ecaco3 were found for the waters of the region of mossoró, with an average of 765 kg ha-1 and the smallest value was observed for grossos and upanema with 626 kg ha-1. for the region of baixo a?u, independent of the origin of the waters, the region of ipanguassu presented the highest values of ecaco3 with an average of 654 kg ha-1 whereas the smallest values were found for the region of carnaubais, with 580 kg ha-1.
Dinámica del Carbono en estanques de peces
Abstract: aquaculture ponds'carbon dynamicsare dominated by physical, chemical and biological transformations in feed and organic and inorganic fertilisation. increasedfish productionhas been associated with an increase incarbon inputin the form of fish-feed exceeding ponds'metabolic capacity,thereby leading to water quality deteriorating due toan accumulationof organic compounds. water quality is a major constraint in terms of increasedfish crop density. the most important carbon loss within aproduction system is associated with co2evaporation;this makes aquaculture ponds become carbon footprints instead of carbon sinks. phytoplankton is the major means of co2 retentionas it captures both that produced by the respiration of all organisms within a particularpond and within the atmosphere. aquaculture production systemsusually have a negativeorganic carbon balance; however,higher carbon recovery is possible but this involves adjusting management practiceand increasedresearch into the pertinent dynamics. feed, feedingpractices, the speciesbeing cultivated, water exchange, aeration, pond depth and the microorganisms living in a pondare factorswhich affect the biogeochemical carboncycle in aquaculture ponds.
Precipitation rates and kinetics of calcite and aragonite in seawater near equilibrium

TAO Xiao-wan,PU Xiao-qiang,

海洋科学 , 2011,
Abstract: 利用“freedrift”开放反应系统, 研究人工海水中近沉淀平衡状态时二氧化碳分压(p(CO2))的变化对方解石、文石沉淀速率及其动力学方程的影响。反应在恒定的温度(25.0℃±±0.2℃)、p(CO2环境下进行, 通过实验得到了不同p(CO2)环境下, 方解石和文石的沉淀速率及动力学方程。研究发现: (1) 晶体类型和碳酸盐碱度相同时, p(CO2越低沉淀速率越大; 饱和度(Ω)和p(CO2相同时, 方解石沉淀速率低于文石, 且p(CO2越高, 沉淀速率越低。(2) 对于方解石, 当p(CO2介于3 050×10?6 和3 200×10?6 之间,1.5<Ω<3.1 时, 反应级数n=2.4; 当p(CO2≈130×10?6, 1.2<Ω<3.0 时, n=2.6; 对于文石, 当p(CO2≈ 2300×10?6, 1.1<Ω< 2.0 时, n=3.2; 当p(CO2≈320×10?6, 1.1<Ω<1.9 时, n=2.0。本研究结果加深了对不同沉积环境下方解石和文石沉淀机制的理解。此外, 不同方解石饱和度(Ωc)条件下方解石和文石沉淀速率的研究为探讨为何现代浅海碳酸盐沉积物以文石为主、而海底沉积物中的自生碳酸钙矿物主要为方解石的现象提供了一种较好的解释方案。
Physico-Chemical and Microbiological Analysis of Potable Water in Jericho and Molete Areas of Ibadan Metropolis  [PDF]
Olusola A. Ladokun, Sarah O. Oni
Advances in Biological Chemistry (ABC) , 2015, DOI: 10.4236/abc.2015.54016
Abstract: This study was carried out to determine the quality of some water supplies in Jericho and Molete areas in Ibadan, Oyo State, Nigeria. A total of 6 water samples (Jericho and Molete) from well, borehole and public tap were randomly selected and analyzed in triplicate for some physico-chemical and microbial parameters. The pH ranged from 5.88 ± 0.01 to 6.88 ± 0.06 while total hardness ranged from 2.60 ± 0.04 ppm to 44.00 ± 1.20 ppm. The temperature ranged from 15.00 ± 0.07 to 18.00 ± 0.21 while conductivity ranged from 230 ± 1.15 to 460 ± 1.26 mho/cm. Alkalinity, Dissolved Oxygen (DO) and Biochemical Oxygen Demand (BOD) ranged from 4.03 ± 0.02 mg/l to 14.88 ± 0.15 mg/l, 0.4 ± 0.02 mg/l to 4.6 ± 0.02 mg/l and 12.80 ± 0.22 mg/l to 26.40 ± 0.72 mg/l respectively. Microbial analysis revealed that all of these water samples were not free from pathogens and thereby not suitable for drinking.
Modo de aplica??o e doses de fosfogesso sobre a condutividade hidraulica, pH e lixivia??o de sódio de um solo salino-sódico da Paraiba
Cavalcante, Lourival F.;Silveira, Ronaldo I.;
Anais da Escola Superior de Agricultura Luiz de Queiroz , 1985, DOI: 10.1590/S0071-12761985000100001
Abstract: samples of a saline-sodic soil (of the irrigated perimeter of s?o gon?alo, souza towm, paraiba state - brazil) that has 61.25 me/100 of exchangeable sodium, were collected at depth 0-30 cm and phosphogypsum was applied in two levels (50% and 100% of the gypsum requirement - gr of the soil). the study v;as realized with the soil put in column of paltic tuble of 40 cm of tall and 5 cm of diametr. both the quantities of the phosphogypsum (31 g (level-50% gr) and 62 g (level-100% gr)) were applied in the surface of the soil and too incorporated at depth 0-15 in such column. the water volume applied was 314 me and the time for star and the finish the leaching was read for to evaluate the hydraulic conductivity. in the end of the leaching each column was dismonted and divided in six parts of 5 cm that were made saturation extracts (1:5) of where were determinated ph, electric conductivity, soluble sodium content and the remaining sodium percentage (rsp). the data evidencied positive effects of the phosphogypsum on hydraulic conductivity of the soil, especially when the chemical corretive was incorporeted at 15 cm under surface of the soil. the hydraulic conductivity (k) valours showed that the less level (50% gr) was more efficient than great level (100% gr of the soil). the data of k for the phosphogypsum incorporated were 2.45 cm/h (level-50% gr) and 1.41 cm/h to level 100% of the gypsum requirement of the soil. in spite the chemistry aspects the electric conductivity data, soluble sodium contents and calours of remaining sodium percentage (rsp) of each interval of 5 cm of the columns , indicated that the phosphogypsum were more efficient in the displacement of exchangeable sodium when it was appliaed in the susrface of the soil. this way the chemical corretive showed to exercise differenced behaviour on physical and chemical properties of the soil alike its way of applications at soil.
Caracteriza??o das águas subterraneas usadas para irriga??o na área produtora de mel?o da Chapada do Apodi
Medeiros, José F. de;Lisboa, Rodrigo de A.;Oliveira, Maurício de;Silva Júnior, Manoel J. da;Alves, Leonardo P.;
Revista Brasileira de Engenharia Agrícola e Ambiental , 2003, DOI: 10.1590/S1415-43662003000300010
Abstract: this research had the objective of studying the quality of irrigation water, especially confined to jandaira calcareous aquifer, in melon producing region of the municipal districts of mossoró, barauna and other surrounding areas. the results of 45 complete analyses (electrical conductivity, ph and concentrations of ca2+, k+, cl- , hco3- and co32-) of water samples belonging to different places, located in the study region were used. the water used for the irrigation collected from tubular wells presented high levels of salinity, varying from 1.25 to 3.00 ds m-1. different areas exist, each one with different salinity values and obstruction risks. in some areas, the salinity and toxicity of the chloride may affect in a significant way the yield of sensitive crops. all analyzed water samples presented low sodicity and high alkalinity.
Germina??o, vigor e crescimento de cultivares de feijoeiro em solu??es salinas
Santos, Patrícia R. dos;Ruiz, Hugo A.;Neves, Júlio C.L.;Almeida, Everson F. de;Freire, Maria B. G. S.;Freire, Fernando J.;
Revista Brasileira de Engenharia Agrícola e Ambiental , 2009, DOI: 10.1590/S1415-43662009000700010
Abstract: to isolate the effects of high concentrations of different salts in solution, response of osmotic pressure, kind of salts, and ph two trials were performed with two bean cultivars: diamante negro and opns 331. the treatments consisted of nano3, nacl, nahco3, kno3, kcl, or khco3 solutions, and a control without salts, in a randomized block design, with four replicates. in the first trial, germination and vigor were studied in 60 mmol l-1 solutions and growth in a nutrient solution enriched with salts at the indicated concentration. in the second trial, the seeds were germinated in deionized water and the seedlings were transplanted to nutrient solution with 60 mmol l-1 salts at the indicated ph, with an additional treatment in which the ph of the nutrient solution with nacl was raised to 8.5 to coincide with the bicarbonate solution. the plant growth variables were evaluated for the two bean cultivars studied. the salinity promoted reductions in growth and the harmful effects caused by high salt concentrations and ph, in both common bean varieties under study, may be ranked in the order: osmotic pressure > alkalinity > bicarbonate ≈ chloride > sodium.
Analysis of Quality Mineral Water of Serbia: Region Arandjelovac  [PDF]
Milo? B. Rajkovi?, Ivana D. Sredovi?, Martin B. Ra?ovi?, Mirjana D. Stojanovi?
Journal of Water Resource and Protection (JWARP) , 2012, DOI: 10.4236/jwarp.2012.49090
Abstract: In this paper it is presented the analysis of basic physical and chemical parameters, alkalinity and acidity, the analysis of kations, anions, heavy metals, microbiological analysis and determination of uranium content in waters of Serbia from 10 springs of Arandjelovac region and 2 samples of bottled drinking water. It is done by different methods of analysis according to which conclusion about the content and the quality of these waters can be made. The pH value of analysed waters shows that waters from springs Maiden spring, Je?ovac, Vrelo and Svin?ine are slightly acid, while mineral waters from springs Aleksijevi?, Exploitation and Talpara are slightly basic. The sample from Olga’s spring has slightly lower pH value. According to Regulation on the hygiene of drinking water, conductivity should be less than 1000 μS/cm. This condition is fulfilled by waters from springs Aleksijevi?, Talpara (ordinary), Maiden and Olga’s spring, Svin?ine and water from city supply system. Springs Je?ovac and Vrelo have slightly increased conductivity, while springs Exploitation and Talpara have conductivity significantly above the allowed values (mineral). Analysed natural mineral waters contain only hydrogencarbonates (bicarbonate). According to the content of bicarbonate it was concluded that samples from springs Exploitation, Talpara (mineral), Vrelo and Svin?ine belong to the category of bicarbonate waters, as the content of hydrogencarbonate in these samples is higher than 600 mg/dm3. Analysed mineral waters don’t show acidity towards methyl orange, which means that acidity of analysed waters comes from dissolved carbon acid.
Floral Species as Environmental Quality Indicators in Jordan: High Salinity and Alkalinity Environments  [PDF]
Ikhlas Alhejoj, Klaus Bandel, Elias Salameh
Journal of Environmental Protection (JEP) , 2015, DOI: 10.4236/jep.2015.65047
Abstract: In this study the occurrence and ecology of plant assemblages are investigated, mainly for use as indicator plants of saline grounds in several locations in Jordan. High alkalinity and H2S-rich water tolerant species of plants are also discussed. Plants growing on salty grounds have distinct composition regarding their place in the taxonomic system. Plant assemblages and their degree of tolerance to salinity as in Karama area in the Jordan Valley are found to be distinct from that of Azraq Sabkha (Cental Jordan) with salt-tolerant flora. Karama area provides the living space for Mesembryanthemum on the saltiest ground, Suaeda further up on wetter surrounding and Salicornia succeeding on moist and less salty grounds. Drier places with rather salty grounds have bushes of Arthrocnemum, while slightly less salty places are preferred by Tamarix tetragyna. When Prosopis bushes appear, salt is only present periodically in the ground, as is also the case with Atriplex halimus and Capparis. In Azraq the former beach of a temporal lake is characterized by two species of Spergularia in its saltier parts and by Tamarix passerinoides. It was recognized that Tamarix, Phragmites, Chenopodium, and Inula represented alkaline water tolerant plants. The study concludes that the salt concentration in the ground is reflected in the composition of the flora growing on it. On the other hand, plants are also found vulnerable to fluctuation in the salt concentration of their environments with different resistance degrees. This makes them excellent bioindicators of salty environments.
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