Experimental investigation of nitrogen compound (nitrates and ammonium ions) removal from water using natural zeolite was carried out in the laboratory of Water Management Department in VGTU. Shallow‐well water samples were taken from a few place situated in Vilnius city and Vilnius district, nitrate concentration was enhanced adding Na NO3 into the samples. Nitrate removal from water solutions was carried out under static conditions: solutions with nitrate concentration of 74–288 mg/l were mixed during one hour with 5 g of 0.315 mm particle‐sized zeolite in an automatic mixer when mixing intensity was 100 min.−1; after 30 min. sedimentation nitrate concentration was measured in all the samples. Ammonium ion removal from water solutions (made of shallow‐well and tap water with NH4Cl) was carried out under static and dynamic conditions (water solutions with 10–15 mg/l of ammonium ion concentration were filtered through 0.315–0.63 mm particle‐sized filter medium). Experimental results show that shallow‐well water (with nitrate concentration of 74–288 mg/l), after one‐hour mixing with 5 g of 0.315 mm particle‐sized zeolite and after 30 min. sedimentation, nitrate concentration stayed the same without any reduction. The same shallow‐well water (with 1–10 mg/l ammonium ion concentration) mixed with 5 g of 0.315–0.63 mm particle‐sized zeolite showed ammonium ion removal efficiency of 72–86 %. For ammonium ion removal from tap water and NH4Cl solution (primary concentration was 15 mg/l) under dynamic conditions, filtering through 400 mm high, 0.315–0.63 mm particle‐sized zeolite filter medium, when filtration rate was 5 mg/l, NH4 + removal efficiency was 95–99.9 %. Ammonium ion removal from shallow‐well water and NH4Cl solution (primary concentration was 10 mg/l) under dynamic conditions, filtered through 95 mm high, 0.315–0.63 mm particle‐sized zeolite filter medium, when filtration rate was 3 mg/l, NH4 + removal in filtered water samples decreased with exponential dependency. The obtained results show that zeolite particles are not suitable for nitrate sorption from water solutions, but 0.315–0.63 mm particle‐sized zeolite can be a very useful sorbent for NH4 + removal from water because of the above mentioned reasons, therefore, further investigations are needed in this area. Santrauka VGTU Vandentvarkos katedros laboratorijoje vykdyti eksperimentiniai azoto junginių (nitratų bei amonio jonų) šalinimo iš vandens, naudojant gamtinius ceolitus, tyrimai. Iš kelių Vilniaus mieste ir rajone esančių šachtinių šulinių paimti vandens mėginiai. Nitratų koncentracijos juose padidėjo pridėjus NaNO3. Nitratai šalinti iš vandeninių tirpalų statiniu būdu, tirpalus (kuriuose nitratų koncentracijos siekė 74–288 mg/l) 1 h maišant su 5 g 0,315 mm stambumo ceolito grūdelių frakcija automatinėje maišyklėje 100 aps./min intensyvumu ir po 30 min nusodinimo išmatuojant juose nitratų koncentraciją. Amonio jonų šalinimas iš vandeninių tirpalų (kurie buvo pasigaminti iš šachtinio šulinio ir vandentiekio vandens pridedant NH4Cl) atliktas statiniu ir dinaminiu būdu (filtruojant vandens tirpalus, kuriuose amonio jonų koncentracijos siekė 10–15 mg/l, per 0,315–0,63 mm ceolito grūdelių užpildo sluoksnį). Eksperimentų rezultatai parodė, kad, maišant šachtinio šulinio vandenį (kuriame nitratų koncentracijos buvo 74–288 mg/l) vieną valandą su 5 g 0,315 mm grūdelių stambumo ceolito frakcija, po 30 min tirpalams nusistovėjus, nustatyta, kad nitratų koncentracija juose nesumažėjo. Tokiu pat būdu maišant šachtinio šulinio vandenį (kuriame amonio jonų koncentracijos buvo 1–10 mg/l) su 5 g 0,315–0,63 mm grūdelių stambumo ceolito frakcija, nustatyta, kad amonio jonų šalinimo efektyvumas mėginiuose siekė 72–86 %. Šalinant amonio jonus iš vandentiekio vandens ir NH4Cl tirpalo (pradinė koncentracija 15 mg/l) dinaminiu būdu, filtruojant per 400 mm aukščio 0,315–0,63 mm stambumo ceolito grūdelių užpildą 5 m/h greičiu, NH4 + šalinimo efektyvumas siekė 95–99,9 %. Šalinant amonio jonus iš šachtinio šulinio vandens ir NH4Cl tirpalo (pradinė koncentracija 10 mg/l) dinaminiu būdu, filtruojant per 95 mm aukščio 0,315–0,63 mm stambumo ceolito grūdelių užpildą 3 m/h greičiu, NH+ 4 koncentracija filtrato mėginiuose mažėjo pagal eksponentinę priklausomybę. Gauti rezultatai parodė, kad ceolito grūdeliai netinka nitratų sorbcijai iš vandeninių tirpalų, bet 0,315–0,63 mm stambumo ceolito grūdelių frakcija galėtų būti ypač tinkamas sorbentas NH+ 4 šalinti iš vandens, todėl būtų tikslinga atlikti daugiau tyrimų šioje srityje. Резюме Экспериментальные исследования очистки воды от азотосодержащих соединений (нитратов и аммония) с применением природного цеолита были проведены в лаборатории кафедры водоснабжения Вильнюсского технического университета им. Гедиминаса. Для этой цели использовалась вода из нескольких шахтных колодцев, находящихся в г. Вильнюсе и его районе, концентрация нитратов была увеличена, дозируя NaNO3. Очистка водных растворов от нитратов производилась статическим методом, растворы (концентрация нитратов составляла 74–288 мг/л) в течение часа смешивали с 5 г цеолита (фракция – до 0,315 мм) автоматической мешалкой при интенсивности 100 об/мин. После 30 мин отстаивания определялась концентрация нитратов. Очистка от аммония водных растворов, полученных из воды шахтных колодцев и водопроводной воды с добавлением NH4Cl, производилась статическим и динамическим методами (водные растворы, в которых концентрация аммония достигала 10–15 мг/л, фильтрировались через загрузочный материал из цеолита с фракцией 0,315–0,63 мм). Результаты эксперимента показали, что концентрация нитратов в растворах не уменьшилась, когда воду из шахтных колодцев, в которых концентрация нитратов достигала 74–288 мг/л, смешивали в течение часа с 5 г цеолита, фракция которого составляла 0,315 мм, и отстаивали в течение 30 мин. При смешивании воды из шахтного колодца, в котором концентрация аммония достигала 10–15 мг/л, с 5 г цеолита, фракция которого составляла 0,315–0,63 мм, эффективность очистки от аммония достигала 72–86 %. При очистке водопроводной воды с раствором NH4Cl от аммония, концентрация которого составляла 15 мг/л, в динамических условиях, фильтруя через загрузочный материал высотой в 400 мм и фракцией 0,315–0,63 мм со скоростью 5 м/ч, эффективность очистки достигала 95–99,9 %. При очистке воды из шахтных колодцев с раствором NH4Cl от аммония (концентрация составляла 10 мг/л) в динамических условиях, фильтруя через загрузочный материал высотой в 95 мм со скоростью 3 м/ч, концентрация NH4 + в фильтрате уменьшалась с закономерностью экспонентной функции. Полученные результаты показали, что загрузка цеолита не способствует сорбции нитратов из водных растворов, в то время как цеолит с фракцией в 0,315–0,63 мм может быть приемлемым сорбентом для очистки воды от NH4 + , поэтому целесообразно проведение дополнительных исследований.

Background, aim, and scope In urban areas, storm water runoff often transports various pollutants, some of which settle and form sediments. In order to have the comprehensive view of the ecological state of storm water runoff recipients, both water and sediments of the stream must be assessed. In the Baltic Sea Area, the Water Framework Directive & HELCOM Recommendations aim to prevent or minimise pollution caused by harmful substances arising from storm water runoff, in order to promote the ecological restoration of the Baltic Sea-one of the most vulnerable seas. The aim of the study was to investigate the toxicity of bottom sediments of a small storm water runoff recipient focusing on the potential impact of successive discharges of urban storm water. Some storm water runoff quality parameters and the toxicity of bottom sediments of recipients was studied in this research. Materials and methods During 9 years, at four discharge points, minimum four grab samples per year at each discharge point were taken for chemical characterisation. General parameters (pH, SS, BOD 7 , COD Cr and TPH) in liquid phase samples were analysed according to standard methods. Annual limit values were taken from the Lithuanian EPA requirements for the management of storm water runoff with a focus on prevention and control of contamination. Eleven composite samples of stream bottom sediments, each consisting of ten sub-samples, were collected in 2006. Toxicity screening from sediments was performed using the plant Lepidium sativum according to modified I. Magone's methodology (Magone I, Bioindication of phytotoxicity of transport emission. In: Kachalova O-L, Zinatne (eds) Bioindication of toxicity of transport emissions in the impact of highway emissions on natural environment. Riga, pp 108-116, 1989). The level of toxic impact of Lepidium sativum (compared to control) was assessed according to the modified method of Wang (Rev Environ Contam Toxicol 126:88-127, 1992). Results The mean pH of urban storm water runoff does not vary much from neutral, but range values are quite different, from 4.0 up to 8.7. The highest concentration of SS reached 800 mg L −1 , TPH-2.4 mg L −1 , BOD 7 -300 mg O 2 L −1 and COD Cr -1,400 mg L −1 . The SS was above the limit in 64% of total amount of grab samples, TPH-37%, BOD 7 -41% and COD Cr -55%. The toxicity J Soils Sediments (

An experimental investigation on the removal of petroleum products (PP) from wastewater by natural sorbent zeolite was carried out in a laboratory on a pilot-scaled test bench. The pilot test bench consisted of: a tank in which gasoline (1 portion) and diesel (1 portion) were mixed mechanically with water; a pump for supplying the mixture to a filter model; a filter model filled with a zeolite layer of 0,2 m height. Zeolite used in this study was from a deposit near the village of Sokyrnytsa in the Ukrainian Transcarpathian region. The test zeolite particle size was 2,53,0 mm; 1,5 2,0 mm; 0,631,0 mm. The concentration of PP in water was measured before and after the filter every hour. The TOG/ TPH analyser was used for concentration measurements. The experimental study showed that the best adsorption results were reached in the filter with 0,631,0 mm particle size of zeolite media. There were 2,25 mg/l of light hydrocarbons left in the filtrate. Such a concentration satisfies the requirements of standards regulating the percentage of PP in treated wastewater.

Natural organic matters are widely used in both surface and underground waters, which are prepared as drinking water. The organic matter are divided into four fractions: very hydrophobic acids (VHA), slightly hydrophobic acids (SHA), hydrophilic charged (CHA) and hydrophilic neutral (NEU). Organic matters are negatively charged so they form complexes with metals. For the determination of organic fractions and metal organic complexes rapid fractionation technique is used. Researches were made in Nida and Preila (III group (open)), Taujenai and Petronys (II group (semi-closed)) water well fields. After fractional studies were made it showed that 90 % of all organic compounds composed of very hydrophobic acids (VHA) and slightly hydrophobic acids (SHA) which consist of a large molecular weight compounds. Over 90 % of bivalent iron composed complex compounds with hydrophobic organic matters. Manganese does not entirely complexes with organic compounds.

Organic matter in drinking water is determined by applying indirect determination methods used for quantitative measurements such as total organic carbon (TOC), chemical oxygen demand (COD), and biochemical oxygen demand (BOD). These analyses require expensive devices, harmful chemical reagents, and are time consuming. Standard water quality tests are inconvenient during start-up or reconstruction of drinking water treatment plants as samples need to be transported to a laboratory and no on-line measurements on plant performing efficiency are available. For practical purposes, less sophisticated and faster methods to determine organic matter are required. One of the methods could be ultraviolet absorption of water at 254 nm wavelength (UV254). It is a technically simple and fast method for determining natural organic matter, requiring neither expensive measurement equipment nor chemical reagents. The present article aims at investigating the possibilities of practical applications of UV254 method to determine the concentration of natural organic matter in ground water. The research proved good correlation between TOC and UV254, as well as between CODMn and UV254. The outcomes of the research indicate that UV254method can be successfully applied to determine natural organic matter concentrations in ground water. Santrauka Organinės medžiagos požeminiame vandenyje nustatomos netiesioginiais kiekybiniais bendrosios organinės anglies (BOA), cheminio deguonies suvartojimo (ChDSMn) ir biocheminio deguonies suvartojimo (BDS) metodais. Šioms analitėms nustatyti būtini brangūs prietaisai, kenksmingi cheminiai reagentai, tyrimai ilgai trunka. Diegiant naujus geriamojo vandens gerinimo įrenginius ir atliekant įrenginių paleidimo, derinimo bei eksploatavimo proceso efektyvumo vertinimą, minėtuosius geriamojo vandens tyrimus nepatogu ir brangu atlikti, todėl šiais atvejais reikia paprastesnio ir greitesnio organinių medžiagų nustatymo metodo. 254 nm bangos ilgio (UV254) ultravioletinių spindulių absorbcija yra techniškai paprastas, spartus organinių junginių koncentracijų nustatymo metodas, jį taikant nebūtina brangi tyrimų įranga bei cheminiai reagentai. Šio darbo tikslas buvo ištirti UV254 metodo tinkamumą organinių junginių koncentracijoms nustatyti požeminiame vandenyje. Atlikus tyrimus apibrėžtos priklausomybės tarp BOA ir UV254 bei tarp ChDSMn ir UV254. Remiantis tyrimų rezultatais galima teigti, kad ultravioletinių spindulių absorbcijos metodas gali būti sėkmingai taikomas organinių junginių koncentracijoms požeminiame vandenyje nustatyti.