Treatment of Textile Wastewater Containing Dyes

In recent years there has been an interest in the study of new methods for the removal of textile dyes from water due to its large-scale use in different industries. For example, paper printing, textile, leather, pharmaceutical, food or technological applications. It is estimated that more than 700 thousand tons of about 10 000 different types of dyes are produced annually. Most of them are of synthetic origin and can generate adverse effects, for example, teratogenic, mutagenic and carcinogenic action. Dyes are mainly applied in the textile industry, and they are usually classified into anionic (acid dyes), cationic (basic dyes) and non-ionic (disperse dyes) dyes. The direct discharge of dyes into the environment can cause various damages to plants and animals: dyes can block the penetration of sunlight, reduce the photosynthetic efficiency of aquatic plants and ultimately destroy the ecological balance of the aquatic ecosystem. This study determines the adsorption efficiency of congo red, methylene blue, rhodamine B and naphthol green B dyes used in textile industry by using the aerogel. To achieve the aim, the effects of adsorbent dosage, pH, dyes concentration, adsorption contact time and temperature of solutions were studied. Kinetic data, equilibrium isotherms and thermodynamic parameters were determined

Formaldehyde removal from wastewater applying natural zeolite

Formaldehyde is one of the most chemically active compounds which is discharged with untreated or just partially treated industrial wastewater. It is hazardous for environment and humans. Formaldehyde vapors can strongly irritate skin, can cause damage to eyes and harm respiratory tract. As long as formaldehyde causes a toxic effect on environment and living organisms, it is necessary to remove it from wastewater which is directed to natural water. There are many methods used for formaldehyde removal from wastewater: biological method, evaporation, membrane separation method. Most of them have disadvantages. Adsorption method has many advantages: it is fast, cheap, and universal, and can be widely used, therefore it was chosen for this research. Experiment was carried out with natural zeolite in different contact time with different concentration formaldehyde solutions. Concentration of formaldehyde was determined applying the Photocolorimetric Method. Method is based on reaction of formaldehyde with chromotropic acid and determination of formaldehyde concentration. Determined average sorption efficiency was highest when formaldehyde concentration was lowest, e. g. 2 mg/l (45.94%) after eight hours of contact time with adsorbent. Sorption efficiency was increasing when the contact time increased, but when the contact time increased to 12 hours, sorption efficiency stayed the same because of the saturation of zeolite. Article in English. Formaldehido šalinimas iš nuotekų panaudojant gamtinį ceolitą Santrauka  Formaldehidas yra vienas iš aktyviausių junginių, kuris išleidžiamas į aplinką kartu su nevalytomis ar iš dalies išvalytomis gamybinėmis nuotekomis. Jis yra pavojingas tiek aplinkai, tiek žmonėms. Formaldehido garai stipriai dirgina akis ir kvėpavimo sistemą. Kadangi formaldehidas yra pavojingas žmonėms ir visiems gyviems organizmams, jis turi būti šalinamas iš gamybinių nuotekų. Sorbcijos metodas turi daug privalumų: jis yra greitas, pigus ir universalus, todėl vienas iš labiausiai perspektyvių vandens valymo metodų – sorbcija. Tai pagrindinė priežastis, kodėl sorbcinis metodas buvo pasirinktas eksperimentiniams tyrimams. Eksperimentiniai tyrimai buvo atlikti naudojat gamtinį ceolitą, buvo parinktas skirtingas formaldehido tirpalo kontakto laikas su adsorbentu ir matuojama teršalų koncentracija po kontakto su adsorbentu. Šis metodas yra paremtas formaldehido reakcija su chromotropine rūgštimi. Sorbcijos efektyvumas augo ilgėjant kontakto su ceolitu laikui, tačiau po 12 valandų efektyvumas nebedidėjo dėl to, kad sorbentas įsisotino. Reikšminiai žodžiai: formaldehidas, vanduo, tarša, nuotekos, pašalinimas, ceolitas, adsorbcija

Investigation and evaluation of surface water pollution with heavy metals and oil products in Kairiai military ground territory

Water pollution with heavy metals, oil and its products is a very important environmental problem. Major part of chemical elements penetrating into the environment gets accumulated in the soil and bed sediment of water bodies. They may also migrate into surface, ground and underground water and spread at great distances. From here, they may enter again nutritional chains and poison living organisms. It is very important and necessary to investigate military territories and evaluate their environmental condition in order to identify the works of their cleaning and optimization of their environmental condition as well as their scope. However, not all the military territories in Lithuania have been sufficiently investigated so far, damage to the environment is not known. Therefore, investigation of such territories is of utmost importance, it is of scientific and environmental significance. This work is dedicated to the investigation and evaluation of surface water and bed sediment pollution with heavy metals and oil products in one of the biggest military grounds of Lithuania ‐ Kairiai Military Ground. Results of the investigation allowed answering the main questions about the most common pollutants, spreading in the environment because of military activities, to determine the level of pollution and most vulnerable territories. Vandens telkinių užtaršos sunkiaisiais metalais ir naftos produktais Kairių kariniame poligone tyrimai ir vertinimas Santrauka. Paviršinio vandens bei jo telkinių dugno nuosėdų tarša sunkiaisiais metalais, nafta ir jos produktais – svarbi aplinkosaugos problema. Teršalai gali sklisti į aplinką garuodami ar migruodami gilyn ir užteršdami gruntinius vandenis. Nors yra žinoma, kad vienas iš karinės veiklos padarinių yra labai užteršti grunto plotai bei vanduo, tačiau vis dar stinga konkrečių duomenų apie tam tikrų teritorijų ruožų užterštumo lygį. Dar nėra pakankamai surinkta faktinės medžiagos apie karinių poligonų teritorijose daromą žalą įvairiems aplinkos komponentams. Šiame darbe įvertinta Kairių karinio poligono vandens telkinių užtarša sunkiaisiais metalais bei naftos produktais. Tyrimams parinktos būdingos vandens telkinių užtaršos vietos viename iš didžiausių – Kairių kariniame poligone. Tyrimo metu nustatyta Kairių poligono teritorijoje esančių paviršinio vandens telkinių ir jų dugno nuosėdų užtarša sunkiaisiais metalais bei vandens užtarša naftos produktais. Tyrimas leido atsakyti į esminius klausimus: kokie teršalai būdingi karinei veiklai naudojamiems vandens telkiniams, kokie yra užterštumo lygiai bei kurios vietos taršai jautriausios. Reikšminiai žodžiai: kariniai poligonai, paviršinio vandens telkiniai, tarša, sunkieji metalai, naftos produktai, dugno nuosėdos. Исследование и оценка загрязненности вод водоемов тяжелыми металлами и нефтепродуктами на территории военного полигона в Кайряй Резюме. Загрязненность вод и осадков дна тяжелыми металлами, нефтью и ее продуктами – важная экологическая проблема. Загрязняющие вещества могут попасть в окружающую среду с выделяющимися из них газами или еще хуже – всасываются в почву, загрязняют грунтовые воды и таким образом могут попасть на территории, находящиеся далеко от источника загрязнения. Хотя уже давно известно, что одним из последствий военных действий являются сильно загрязненные поверхностные воды и почва, все еще не хватает конкретных данных об уровне загрязнения отдельных участков. Еще не собрано достаточно фактической информации о негативных факторах, которые испытывают отдельные компоненты окружающей среды на территориях военных полигонов. В статье представлено исследование, которым была установлена загрязненность поверхностных вод на территории полигона в Кайряй тяжелыми металлами и нефтепродуктами, а также осадков дна тяжелыми металлами. Для исследования были подобраны типичные места на одном из самых больших полигонов Литвы – в Кайряй. Результаты исследования помогли ответить на вопрос о том, какие загрязняющие вещества в поверхностных водах, используемых для военных действий, встречаются чаще всего, какой степени достигло загрязнение, и т. п. Ключевые слова: военные полигоны, поверхностные воды, загрязненность, тяжелые металлы, нефтепродукты, осадки дна. Firstd Published Online: 14 Oct 201

Numerical modeling of kinetics of heavy metal sorption from polluted water

Water protection is one of the most important priorities of environmental protection. It is necessary to reduce pollution of wastewater in order to reduce pollution of drinking‐water and water pools. One of the most dangerous wastewater pollutants are heavy metals (HM). They have a negative influence on people and aquatic water systems. The paper analyses possibilities of the sorption method application for heavy metal elimination from waste‐water. Experimental investigation of HM sorption from water and numerical modeling usage possibilities for prognosis of the HM sorption kinetic process was carried out as well as experimental study of HM elimination efficiency dependence on sorption time of HM from wastewater, when using sorbents. Two pseudo kinetic models, i e the pseudo first‐ and second‐order models, were developed on the basis of experimental investigation. These models were applied in numerical modeling in the computer program PHOENICS. The results of the computer program PHOENICS and those of experimental investigation describing HM sorption from water were compared. After comparing the two pseudo models, it is determined that the pseudo second‐order model suits better for HM sorpti. Skaitinis sunkiųjų metalų sorbcijos iš užteršto vandens kinetikos modeliavimas Santrauka Vandens apsauga yra vienas iš svarbiausių aplinkos apsaugos prioritetų. Norint sumažinti vandens telkinių ir geriamojo vandens taršą, būtina mažinti išleidžiamų nuotekų užterštumą. Vieni iš pavojingiausių nuotekų teršalų – sunkieji metalai, galintys sukelti neigiamą poveikį žmonėms bei vandens ekosistemoms. Straipsnyje nagrinėjama sorbcinio metodo taikymo sunkiesiems metalams šalinti iš nuotekų galimybės, taip pat aprašomi sunkiųjų metalų sorbcijos iš vandens kinetikos tyrimai ir skaitinio modeliavimo taikymas sunkiųjų metalų sorbcijos iš vandens kinetikos proceso prognozei. Atlikti eksperimentiniai sunkiųjų metalų šalinimo iš nuotekų sorbentais efektyvumo priklausomybės nuo laiko tyrimai. Remiantis eksperimentinių tyrimų rezultatais, buvo sudaryti du pseudokinetiniai modeliai – pirmosios eilės ir antrosios eilės. Šie modeliai pritaikyti skaitiniame modeliavime, naudojant kompiuterinę programą PHOENICS. Atliekant skaitinį modeliavimą gauti sunkiųjų metalų sorbcijos iš vandens rezultatai palyginti su eksperimentinių tyrimų rezultatais. Palyginus abiejų pseudomodelių rezultatus nustatyta, kad pseudo- antrosios eilės modelis geriau atspindi sunkiųjų metalų sorbcijos iš vandens kinetiką. Firstd Published Online: 14 Oct 2010 Reikšminiai žodžiai: sorbcija, sorbentai, sunkieji metalai, pseudokinetiniai modeliai, skaitinis modeliavimas

The extent of influence of O–D matrix on the results of public transport modeling

A rapidly developing and equality-based society needs a reliable and attractive public transport system. With booming mobility in Lithuania, a great importance has been attached to the sustainable development concept, and public transport has been given priority in the urban transport system. Accessibility and comfort of public transport are essential indicators that guarantee equal travelling opportunities for all people. Transport modelling is the only economical and sufficiently reliable way to carry out a forward assessment of the impact of innovations to be applied to the overall system without involvement of passengers. This paper considers estimation of the origin–destination (O–D) matrix and its size correction. The public transport (PT) system of Vilnius City was taken as a basis for the research. Modelling of Vilnius City public transport was carried out with the help of VISUM software. Modelling of the public transport route network in Vilnius is aimed at improving the quality of life of inhabitants of the city. The O–D matrix is one of the key elements in modelling. Reliability of modelling results is based on reliability and size of the matrix. Although many scientists analyse the problem of estimating an O–D matrix, this paper focuses on the size of the O–D matrix required in order to give reliable results in PT modelling. During the first step, the matrix of 230 transport districts is estimated, which is reduced by 10 percent with every following step. The aim of this article is to find the break point in the size of O–D matrix where the reliability of PT modeling results falls

Relative humidity and temperature impact to ozone and nitrogen oxides removal rate in the experimental chamber /

The indoor ozone and nitrogen oxides concentration depends on their outdoor concentrations, indoor sources and their removal rates on the surfaces. The paper presents experimental data of the of ozone and nitrogen oxide removal in the chamber. The ambient conditions were simulated by four combination of different temperature and relative humidity levels. The impact of temperature (T = 20 °C and T = 30 °C) and relative humidity (RH = 24% and RH = 80%) on the deposition velocity was estimated. It was found that the ozone removal in the chamber was influenced more by temperature, and the nitrogen oxides removal was affected more by relative air humidity. The results showed that higher ambient temperature (T = 30 °C) increased the ozone removal rate in the chamber 3 times on an average, and high relative humidity (RH = 80%) increased the NOx removal rate 4.5 times in comparison with the initial conditions (T = 20 °C; RH = 24%). The obtained deposition velocities varied in the range (0.0045–0.0137) cm s−1 for ozone and in the range (0.002-0.0129) cm s −1 for nitrogen dioxide. Santrauka Ozono ir azoto oksidų koncentracija patalpose priklauso nuo šių teršalų koncentracijos lauke, jų šaltinių patalpose ir šių teršalų suirimo greičio ant skirtingų paviršių. Darbe nagrinėjamas ozono ir azoto oksidų suirimas eksperimentinėje kameroje. Skirtingos mikroklimatinės sąlygos buvo sukuriamos naudojant keturių skirtingų temperatūrų ir santykinių oro drėgnių lygių derinius. Vertinta temperatūros (T = 20 °C ir T = 30 °C) ir santykinio drėgnio (RH = 24 % ir RH = 80 %) įtaka tiriamų teršalų suirimui. Nustatyta, kad ozono suirimui daugiau įtakos turėjo temperatūra, o NOX irimui – santykinis oro drėgnis. Nustatyta, kad aukštesnė aplinkos temperatūra (T = 30 °C) paspartina ozono suirimą kameroje vidutiniškai tris kartus, o didelis santykinis drėgnis (RH = 80 %) paspartina NOX suirimą 4,5 karto, lyginant su pradinėmis sąlygomis (T = 20 °C; RH = 24 %). Eksperimento metu ozono suirimo greitis kito nuo 0,0045 iki 0,0137 cm s−1, o azoto oksidų – nuo 0,002 iki 0,0129 cm s−1. Резюме Концентрации озона и оксидов азота в помещениях зависят от их концентрации в открытом воздухе, источникахвнутри помещений и скорости их распада на поверхностях. В статье представлены экспериментальные данные по распаду озона и оксидов азота в камере при разных микроклиматических условиях, созданных с применением четырех комбинаций температур и относительной влажности. Оценивалось воздействие температуры (T = 20 °С и Т = 30 °С) и относительной влажности воздуха (RH = 24% и RH = 80%) на скорость осаждения. Было обнаружено,что на распад озона в камере большее влияние оказывает температура, а на распад оксидов азота – относительная влажность воздуха. Результаты показали, что при повышении температуры окружающей среды (T = 30 °С) увеличилась скорость распада озона в камере в 3 раза по сравнению со средней, а при высокой относительной влажности (RH = 80%) увеличилась скорость распада NOx в 4,5 раза по сравнению с начальными условиями (T = 20 °C; RH = 24%). Полученные для озона скорости осаждения варьировали в пределах (0,0045−0,0137) cм с-1, а для оксида азота – в пределах (0,002−0,0129) cм с-1. Reikšminiai žodžiai: ozonas, azoto oksidai, santykinis oro drėgnis, temperatūra, kamera, suirimo greitis Ключевые слова: озон, оксиды азота, относительная влажность, температура, камера, скорости осаждени

Evaluation of the requirement for passenger car parking spaces using multi-criteria methods

The present situation shows that the parking infrastructure in residential areas of Vilnius does not satisfy the existing level of motorization. Every evening people come home from work and end up parking cars on lawns, cycle and pedestrian paths, playgrounds, fire accesses and etc. In Lithuania, this problem emerged with the growing number of cars. There have been attempts to address parking shortage issues 20–30 years ago by building metal above-ground garages and underground car parks; but such solutions focused on existing burning needs alone. As a result, the current parking situation in residential areas is chaotic. This problem stems from the ineffectiveness of responsible institutions, which maintain the status quo. Consequently – as no car parking development projects are planned and implemented as well as no required statistical data is collected regarding conditions of car parking and etc. – people are forced to look for a solution by themselves, thus end up parking on lawns or playgrounds. This article aims to apply multi-criteria solutions (Multiple Criteria Decision Making – MCDM), which would allow indicating the worst passenger car parking conditions in residential areas from the social, economic and environmental points of view. Besides, it pursues identifying and substantiating the choice of territories that require the development of car parking solutions

Modelling a passenger car system based on the principles of sustainable mobility in Vilnius City

The growing rate of motorization and the use of passenger cars have a worsening effect on traffic conditions in the streets of Vilnius City. Moreover, adverse urbanisation processes (i.e. migration to suburban areas) make a huge effect on the behaviour of travelling. A deeper analysis of these processes requires large data amounts and techniques for analysing transportation. The study is aimed at preparing and assessing the scenarios of developing passenger car transport through the prism of sustainability indicators. A plan for case study-based hypothetical mobility management explores a series of future scenarios improving transportation diversity and changes in modes for travellers. These scenarios are developed with respect to developments anticipated in the Master Plan of the City of Vilnius and aims at identifying the effect of a new public transport network on the motorized transport system during the morning peak in the hypothetical year 2025. Mobility management through transportation diversity increases travelling options, encourages travellers to choose the most efficient mode and tends to eliminate car dependency that otherwise occurs in urban areas. The development of a public transport route network in Vilnius City creates real preconditions for implementing a sustainable transport system thus giving a priority to the development of a new and fast transport mode. The planned routes of the new transport mode allows significantly reducing the necessity for the use of private motorized transport and influencing the total structure of travels thus making it possible for a large number of people to reach destination by public transport

TRACE METAL CONCENTRATION AND SPECIATION IN STORM WATER RUNOFF ON IMPERVIOUS SURFACES

Urban storm water runoff (USWR) often transports various trace metals, affecting the quality of receiving waters. Metal concentration and speciation in USWR were investigated by analysing data collected during a storm event on 19 July 2012. USWR samples were taken from a low–traffic intensity road, a pathway in a car–free pedestrian zone, and a galvanized metal roof located in the area of Vingio Park in the city of Vilnius, Lithuania. The metals were mostly in the insoluble form at all three sites, being more than 80% the total amount measured, irrespective of the water quality characteristics and types of surface area. The partitioning coefficient (log Kd) of trace metals decreases in the order Zn > Cu ≈ Mn ≈ Pb >> Cd. The USWR types characterized by a higher pH or dissolved organic carbon(DOC) concentration produced a higher fraction of Cd, Mn, Pb, and Zn bound to fulvic acids (FA)