Determination of organic carbon in mineral and thermal water

Total organic carbon (TOC) in mineral and thermal waters was measured and statistically evaluated. A calibration curve was constructed, and accuracy and reliability, as well as repeatability and reproducibility, were evaluated in pool waters. The results showed that the method is suitable for the determination of TOC in different thermal and mineral water samples. The results were statistically evaluated. The method was tested within interlaboratory comparison. The measurement deviations were up to 4 %, which ensures the accuracy and reliability of the results

Nanofiltration of acid whey after ultrafiltration protein recovery process

After the ultrafiltration of acid whey, nanofiltration of permeate was performed. The use of NFT-50 membrane for whey nanofiltration was studied. Whey flux was measured, and fouling potential was determined. Some general chemical parameters of whey were measured. The results showed that chemical parameters decreased after the treatment. Filter cake was formed, and reversible fouling prevailed at 40 bar

Removal of inorganic As5+ from a small drinking water system

The drinking water from a small drinking water system contained arsenic in a concentration of about 50 ▫$mu$▫g/L. Chemical analyses showed that the pentavalent form of arsenic was present. Since the MCL value is 10 ▫$mu$▫g/L, it was necessary to implement a technological treatment to make the water suitable for drinking. In order to do so, two technologies were suggested: activated alumina and ▫$alpha$▫-FeOOH (TehnoArz, TA) adsorption media. Experiments using both adsorption media were performed on a laboratory scale. It was possible to remove arsenic to below 1 ▫$mu$▫g/L. The maximal adsorption capacity was found to be 12.7 mg of As5+ per gram of ▫$alpha$▫-FeOOH. Moreover, all the important physico- chemical parameters of the water remained practically unchanged after the treatment. Only a slight release of iron from the media was observed. The Fe-As bond was studied by means of chemical analysis and X-ray powder diffraction. Finally, in addition to showing the capability of arsenic removalby ▫$alpha$▫-FeOOH, a comprehensive optimization of the technological parameters of the selected technology is provided

Lead and pesticide removal by carbon block filter

The aim of the research was to determine the reduction of pesticide, lead, chlorine and bacteria in drinking water after the filtration using carbon block filter. The effectiveness of filter was determined by general and physico-chemical analysis on drinking water samples before being treated with filter. We made some rapid test using drinking water test WS-425B. The results show that the total hardness in filtered water decreased at the start, while the concentration of K+ increased tremendously. After about 10 L of water was used, the hardness of water increased to the value of untreated drinking water, while the concentration of K+ decreased down to 20 mg/L. The concentrations of atrazine and lead in water samples were reduced after being treated with filter. Nitrate-ions were reduced and probably exchanged with chloride-ions from filter due to increased electrical conductivity

A comparison of cadmium content in water samples with two methods

Cadmium (Cd) is a natural element found in soils and rocks. It is used in the metal industry, plastics, ceramics, and in the manufacture of batteries. Due to leaching, it could be found in drinking water sources. Cadmium is toxic to humans. Thus, the aim of the research was to determine Cd in real water samples. A comparison was made between the methods of inductively coupled plasma mass spectrometry ICP-MS and graphite furnace atomic absorption spectroscopy (GF-AAS). The measurement uncertainty was determined. We have developed a useful method for trace analysis of Cd in waters in the microgram per litre range

Predobrada kompostne procjedne vode procesom koagulacije/flokulacije praćene filtarskom prešom

Compost leachate was treated with coagulation/flocculation followed by filtration in order to obtain effluent suitable for further purification by reverse osmosis process. The poly aluminium chloride coagulant and the poly acryl amide flocculant were applied for coagulation/flocculation process. Filtration tests were performed to choose the proper fabric for filtration of compost leachate. There were huge differences between compost leachate samples’ properties taken at the plant; therefore, it was difficult to determine the optimum coagulant/flocculant dosage. It was found that, among the fabrics available, only one was appropriate, and was made of polypropylene. With other filter fabrics the pressure during the filtration increased above 6 bar, which means above the highest specified allowed pressure for the device used. The filtration was carried out with several differently pretreated samples of compost leachate. The turbidity was reduced by as much as 89.8 %. The particle-size distribution analyses showed that most colloids and suspended solids were removed after the treatment. The results indicate that combination of coagulation/flocculation followed by filtration is not adequate for proper treatment of compost leachate, and some other technique, such as electrocoagulation, ultrafiltration, and nanofiltration need to be investigated.Kompostne procjedne vode primarno su obrađene koagulacijom/flokulacijom nakon čega je slijedila filtracija da bi se dobio efluent pogodan za daljnje pročišćavanje postupkom reverzne osmoze. Aluminijev klorid je u procesima koagulacije/flokulacije upotrijebljen kao koagulant, a poliakrilamid kao flokulant. Provedena su ispitivanja filtracije kompostne procjedne vode da bi se odabrala odgovarajuća tkanina za filtraciju. S obzirom na veliku fluktuaciju u sastavu procjedne kompostne vode izuzete na postrojenju, bilo je teško odrediti optimalnu dozu koagulanta/flokulanta. Utvrđeno je da je od dostupnih tkanina samo jedna odgovarajuća, a bila je izrađena od polipropilena. Kod drugih filtarskih tkanina tlak je tijekom filtracije porastao iznad najvišeg dopuštenog tlaka za upotrijebljeni uređaj koji je iznosio 6 bar. Filtracija je provedena na nekoliko različitih prethodno obrađenih uzoraka kompostne procjedne vode. Zamućenje se smanjilo za čak 89,8 %. Analiza raspodjele veličine čestica pokazala je da je većina koloida i suspendiranih tvari uklonjena nakon obrade. Rezultati pokazuju da kombinacija koagulacije/flokulacije i filtracije nije primjerena za pravilnu obradu kompostne procjedne vode te je potrebno istražiti neke druge tehnike poput elektrokoagulacije, ultrafiltracije i nanofiltracije

Kinetic Studies of Catalytic Ozonation of Atrazine

The aim of our work was to degrade atrazine by the ozone treatment of both a model and the original drinking water samples, using Pt-catalyst, and to evaluate the performance of this catalyst. The rate constant for the reaction of atrazine with ozone was determined in the model water sample. The activation energies and the reaction orders of ozone decomposition were determined in both the model and the drinking water samples. Ozone treatment using Pt-catalyst has some influence on the loss of atrazine in the sources of drinking water. The concentration of some metabolites in the model and drinking water was observed during ozone treatment. The toxicity of atrazine to crustacean Daphnia magna in the original drinking water and in the ozone treated water samples was also assessed

The effectiveness of novel chlorine dioxide in drinking water disinfection

The presence of E. coli in drinking water is not very common, however drinking water polluted with E. coli can lead to infection and could cause serious illness. Water contamination can lead to adverse health effects, including gastrointestinal illness, reproductive problems, and neurological disorders. More than 200 diseases are derived from polluted water. The main objective of present research was to evaluate the effectiveness of novel chlorine dioxide for the inactivation of E. coli in drinking water. Chlorine dioxide is made of two compounds: liquid sodium chlorite and solid sodium-peroxodisulphate »in situ«. Chlorine dioxide composition is in accordance with water treatment regulation [1]. In this experiment, different concentrations of chlorine dioxide were added at different temperatures in order to determine the optimal conditions for E. coli removal from drinking water. Results showed that optimal dose is 0.2 mg/L of chlorine dioxide at room temperature, while the same dose was effective at increased temperatures at 30 °C and 40 °C. The contact time was less than 1 min