Limitation of hardness from thermal water by means of nanofiltration

2013 ◽  
Vol 67 (9) ◽  
pp. 2025-2032 ◽  
Author(s):  
Csilla Maria Tonko ◽  
Andras Kiraly ◽  
Peter Mizsey ◽  
Gyorgy Patzay ◽  
Edit Csefalvay

Geothermal conditions are extremely favourable in Hungary. Thermal water is accessible in 70% of the territory of the country, with a lowest temperature of 30°C. For energetic purposes, it can be utilized in two different ways: for supplying heat or generating electricity. In relation to utilization, one of the most serious problems derives from the chemical composition of thermal water. The present paper investigates the opportunities of preventing scaling by nanofiltration. Experiments were performed on a Thin Film NF DK membrane, thermostated at 50°C and at a pressure of 3.5 MPa with four different samples (from four Hungarian cities – Eger, Mezőkövesd, Bogács, Miskolc-Tapolca) using batch plant. Reproducibility of experiments was also investigated using water samples from Komárom at 50 and 60°C. The results showed that NF DK could achieve high retention of divalent ions. The results of the second phase of the experiments proved that water flux and rejections were very stable. After filtration, the scaling properties of thermal water were simulated with the help of chemical equilibrium modelling software, called Visual MINTEQ 3.0. The results of the permeate samples prove that nanofiltration is a successful process in preventing scaling of thermal water for further use.

2012 ◽  
Vol 16 (1) ◽  
pp. 157-166 ◽  
Author(s):  
I. Delgado-Outeiriño ◽  
P. Araujo-Nespereira ◽  
J. A. Cid-Fernández ◽  
J. C. Mejuto ◽  
E. Martínez-Carballo ◽  
...  

Abstract. Hydrothermic features in Galicia (northwest Spain) have been used since ancient times for therapeutic purposes. A characterization of these thermal waters was carried out in order to understand their behaviour based on inorganic pattern and water-rock interaction mechanisms. In this way 15 thermal water samples were collected in the same hydrographical system. The selected thermal water samples were classified using principal component analysis (PCA) and partial least squares (PLS) regression analysis in two groups according to their chemical composition: group I with the young water samples and group II with the samples with longest water-rock contact time. This classification agreed with the results obtained by the use of geothermometers and hydrogeochemical modelling, where the samples were classified into two categories according their residence time in the reservoir and their water-rock interaction.


Author(s):  
V.V. Lapenko ◽  
L.N. Bikbulatova ◽  
E.M. Ternikova

Water is very important for humans, as it is a solvent for metabolic products. Moreover, it is necessary for metabolism, biochemical and transport processes. The elemental status in persons depends on the geochemical environment and consumption of bioelements with food and water. The aim of the paper is to conduct a comprehensive assessment of chemical composition of drinking tap water in Khanty-Mansiysk and Salekhard. Materials and Methods. The chemical composition of 100 samples of drinking tap water was analyzed by atomic absorption spectrometry, spectrophotometry and capillary electrophoresis. All in all, there were 50 samples from Khanty-Mansiysk and 50 samples from Salekhard. The results were compared with Sanitary Rules and Norms 2.1.4.1074-01. Results. Drinking tap water in Salekhard contains a significantly higher concentration of iron, which is much above the maximum allowable concentration, if compared to water samples in Khanty-Mansiysk (p=0.03). In the cities under consideration, the water undergoes high-quality reagent-free treatment. However, the deterioration of the water supply networks in Salekhard is 3 times as high as in Khanty-Mansiysk. Calcium and magnesium concentration in water samples from Khanty-Mansiysk is 5.6 and 3.9 times lower than the MAC; in water samples from Salekhard calcium concentration is 6.3 (p=0.008) and magnesium concentration 4.6 (p<0.001) times lower than the MAC. Conclusion. The consumption of ultra-fresh drinking water leads to low intake of bioelements, which are a part of enzymes contributing to the human antioxidant defense and can result in manifestation of cardiovascular diseases. This is especially true for Salekhard with very soft drinking water and high iron concentration, which excess can exhibit prooxidant properties. Keywords: tap water, bioelements, northern region, antioxidants. Вода является важнейшим соединением для человека: необходима в качестве растворителя продуктов метаболизма и протекания обменных, биохимических и транспортных процессов. Элементный статус организма человека зависит от геохимического окружения и поступления биоэлементов с пищей и водой. Цель. Провести комплексную оценку химического состава водопроводной воды городов Ханты-Мансийск и Салехард. Материалы и методы. Методами атомно-абсорбционной спектрометрии, спектрофотометрии и капиллярного электрофореза проанализирован химический состав 100 проб водопроводной воды: по 50 из Ханты-Мансийска и Салехарда. Результаты сравнивали с СанПиН 2.1.4.1074-01. Результаты. В водопроводной воде Салехарда установлена превышающая ПДК и достоверно более высокая концентрация железа сравнительно с водой Ханты-Мансийска (р=0,03). При условии качественной безреагентной водоподготовки в изучаемых городах это обусловлено изношенностью водопроводных сетей в Салехарде, более чем в 3 раза превышающей этот показатель в Ханты-Мансийске. Концентрация кальция и магния в воде Ханты-Мансийска в 5,6 и 3,9 раза ниже ПДК; в воде Салехарда – в 6,3 (р=0,008) и 4,6 (р<0,001) раза ниже ПДК соответственно. Заключение. Употребление ультрапресной питьевой воды на фоне очень малого поступления с водой биоэлементов, входящих в состав ферментов антиоксидантной защиты организма человека, может привести к манифестации кардиоваскулярных заболеваний. Это особенно актуально для г. Салехарда с очень мягкой питьевой водой с повышенным содержанием железа, избыток которого может проявлять прооксидантные свойства. Ключевые слова: водопроводная вода, биоэлементы, северный регион, антиоксиданты.


Author(s):  
Л.И. АМБАРЦУМЯН ◽  
Е.Н. ГУБА ◽  
М.В. ГУСЕВА ◽  
С.Н. ДИЯНОВА ◽  
В.В. ИЛЛАРИОНОВА

Проведены исследования качества 12 образцов питьевой бутилированной воды в условиях аккредитованной испытательной лаборатории. Исследование информативности маркировки образцов воды выявило, что не все производители выполняют требования ТР ТС 022/2011. Дана оценка органолептических, физико-химических и микробиологических показателей питьевой воды. Определены критерии безвредности химического состава образцов. Исследован макро- и микроэлементный состав. Выявлена необходимость повышения степени ответственности производителей при формировании качества. The quality of 12 samples of bottled drinking water was studied in an accredited testing laboratory. The study of informative labeling of water samples revealed that not all manufacturers fulfill the requirements of TR TS 022/2011. The evaluation of organoleptic, physicochemical and microbiological indicators of drinking water is given. Criteria of harmlessness of the chemical composition of samples are defined. It is investigated macro- and microelement composition of drinking water. The necessity to increase the degree of responsibility of producers in the formation of quality is revealed.


2010 ◽  
Vol 93-94 ◽  
pp. 231-234
Author(s):  
B. Hongthong ◽  
Satreerat K. Hodak ◽  
Sukkaneste Tungasmita

Strontium substituted hydroxyapatite(SrHAp) were fabricated both in the form of powder as reference and thin film by using inorganic precursor reaction. The sol-gel process has been used for the deposition of SrHAp layer on stainless steal 316L substrate by spin coating technique, after that the films were annealed in air at various temperatures. The chemical composition of SrHAp is represented (SrxCa1-x)5(PO4)3OH, where x is equal to 0, 0.5 and 1.0. Investigations of the phase structure of SrHAp were carried out by using X-ray diffraction technique (XRD). The results showed that strontium is incorporated into hydroxyapatite where its substitution for calcium increases in the lattice parameters, and Sr3(PO4)2 can be detected at 900°C. The SEM micrographs showed that SrHAp films exhibited porous structure before develop to a cross-linking structure.


Konversi ◽  
2018 ◽  
Vol 5 (1) ◽  
pp. 22
Author(s):  
Stevano Victor M. ◽  
Bayu Andhika ◽  
Isna Syauqiah

Abstrak- Telah dilakukan pemanfaatan cangkang bekicot (Achatina fulica) sebagai adsorben logam berat seng (Zn). Penelitian ini bertujuan untuk mengetahui jumlah kitosan yang didapat dari cangkang bekicot, dan mengetahui kemampuan adsorben kitosan dalam uji adsorpsi yang menggunakan sampel air yang tercemar seng (Zn). Pembuatan kitosan dari cangkang bekicot dilakukan dengan dua tahap yaitu tahap pembuatan kitosan dengan variasi ukuran kitosan 250 micron  dan 355 micron. Tahap pembuatan kitosan terdiri dari pembuatan serbuk cangkang bekicot, deproteinasi, demineralisasi, depigmentasi dan deasetilasi. Tahap  ke dua yaitu uji penyerapan kitosan terhadap logam berat seng (Zn) dengan variasi jumlah massa kitosan yang digunakan yaitu: 1 gram, 3 gram, 6 gram dan 9 gram. Sampel tersebut diuji dengan menggunakan Atomic Absorption Spectrophotometric  (AAS) untuk mengetahui konsentrasi logam berat seng (Zn) yang terkandung di dalamnya. Hasil penelitian menunjukan bahwa kitosan yang didapat dari cangkang bekicot untuk ukuran 250 micron yang sebesar 95,27%, dan untuk ukuran 355 micron yaitu sebesar 96,18%. Daya serap optimum kitosan didapat pada kitosan berukuran 250 micron  dengan massa kitosan 9 gram. Kata kunci: Adsorbsi, mikron, cangkang bekicot dan logam berat seng (Zn) Abstract- The used of snail shell (Achatina fulica) as adsorbent of heavy metals zinc (Zn). This study aims to determine the amount of chitosan derived from snail shells, and knowing the ability of chitosan adsorbent in adsorption tests using water samples were contaminated zinc (Zn). Preparation of chitosan from the shells of snails be done in two phases: the manufacture of chitosan with chitosan size variation of 250 micron and 355 micron. Production stage consists of the manufacture of chitosan powder snail shells, deproteinization, demineralization, depigmentasi and deacetylation. The second phase of the test chitosan absorption of heavy metals zinc (Zn) with a variation of the mass amount of chitosan that is used as follows: 1 gram, 3 grams, 6 grams and 9 grams. The sample is tested by using Atomic Absorption Spectrophotometric (AAS) to determine the concentration of heavy metals zinc (Zn) contained in it. The result showed that chitosan is obtained from the snail shell to the size of 250 microns, which equal to 95.27%, and for the size of 355 microns that is equal to 96.18%. Optimum absorption of chitosan obtained at chitosan measure 250 microns with a mass of 9 grams of chitosan.                                                                                                                                        Keywords: Adsorption, micron, snail shells and heavy metals zinc (Zn).


Polymers ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 2526
Author(s):  
Wenyao Shao ◽  
Chenran Liu ◽  
Tong Yu ◽  
Ying Xiong ◽  
Zhuan Hong ◽  
...  

Using polyethylenimine (PEI) as the aqueous reactive monomers, a positively charged thin-film nanocomposite (TFN) nanofiltration (NF) membrane with enhanced performance was developed by successfully incorporating graphene oxide (GO) into the active layer. The effects of GO concentrations on the surface roughness, water contact angle, water flux, salt rejection, heavy metal removals, antifouling property, and chlorine resistance of the TFN membranes were evaluated in depth. The addition of 20 ppm GO facilitated the formation of thin, smooth, and hydrophilic nanocomposite active layers. Thus, the TFN-PEI-GO-20 membrane showed the optimal water flux of 70.3 L·m−2·h−1 without a loss of salt rejection, which was 36.8% higher than the thin-film composite (TFC) blank membrane. More importantly, owing to the positively charged surfaces, both the TFC-PEI-blank and TFN-PEI-GO membranes exhibited excellent rejections toward various heavy metal ions including Zn2+, Cd2+, Cu2+, Ni2+, and Pb2+. Additionally, compared with the negatively charged polypiperazine amide NF membrane, both the TFC-PEI-blank and TFN-PEI-GO-20 membranes demonstrated superior antifouling performance toward the cationic surfactants and basic protein due to their hydrophilic, smooth, and positively charged surface. Moreover, the TFN-PEI-GO membranes presented the improved chlorine resistances with the increasing GO concentration.


MRS Advances ◽  
2019 ◽  
Vol 4 (37) ◽  
pp. 2023-2033
Author(s):  
Barys Korzun ◽  
Marin Rusu ◽  
Thomas Dittrich ◽  
Anatoly Galyas ◽  
Andrey Gavrilenko

ABSTRACTThin films of haycockite Cu4Fe5S8 on glass substrates were deposited by flash evaporation technique from powders of this compound. The composition of thin films correspond to the atomic content of Cu, Fe, and S of 24.13, 27.90, and 47.97 at.% with the Cu/ Fe and S/ (Cu + Fe) atomic ratios of 0.87 and 0.92 respectively, whereas the corresponding theoretical values for this material amount to 0.80 and 0.89. The as-prepared thin films of haycockite consist of a set of separate fractions of approximately identical areas of about 400 - 600 μm2. It can be assumed that this structure evolved during cooling down of thin films since it completely covers the surface of thin films. A small inclusion of a second phase with the chemical composition close to talnakhite Cu9Fe8S16 is also observed. Haycockite Cu4Fe5S8 is found to be a direct gap semiconductor with the energy band gap Eg equal to 1.26 eV as determined using both transmission and surface photovoltage methods.


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