An interdisciplinary learning approach to ecological business: Using examples of best practice

It is a widely held view among educationists that the most effective way to facilitate a holistic learning approach is to present visual, ready-to-use, practical examples. Thus, our study follows the general scope of the course “Socially responsible ecological business”, which is currently offered to master students at the Vilnius Gediminas Technical University (VGTU). We contend that teaching materials should be presented visually using case studies and examples. Indeed, simple guidance is one of the vital learning tools for students. Accordingly, and in line with the aims of the course, the observations and experience of differences in global culture and our inclusion of a wide range of ecological examples were central to the design of our international case study. In particular, students found the case study on ecological business both useful and applicable in the real world

Removal of ammonium Ions from digested sludge fugate by using natural zeolite

Wastewater treatment loadings with total nitrogen can increased by introducing fugate that is saturated with ammonium ions, generated when dewatering wastewater treatment sludge. In this article the possibility to reduce the concentration of ammonium ions in the fugate by the use of natural zeolite (Transcarpatian clinoptilolite) has been analysed. Lab-scale experiments were carried out with different particle sizes zeolite: 0.8–1.6 mm, 1.6–2.5 mm and 2.5–3.2 mm. At the first stage of the experiments, zeolite particles were mixed with fugate and left to settle until a 99% efficiency of ammonium ion removal was achieved. At the second stage, ammonium ions were removed from the fugate by filtering this liquid through zeolite where the 70–92% efficiency was achieved. Zeolite saturated with ammonium ions possibly can be used in agriculture as nitrogenous fertilizers. Obtained fertilizer grade of zeolite saturated with fugate can also be produced from the high ammonium nitrogen concentration side-streams separated from wastewater flow from sludge digestion processes. First published online: 18 May 201

Sustainability assessment of heavy metals and road maintenance salts in sweep sand from roadside environment

The main aim of this study was to characterize heavy metal compounds of sweep sand particles in the city of Vilnius (Lithuania). These research results provide new insight into the distribution and variation of heavy metal compounds in sweep sand in the studied area. The results of this investigation reflect the level of heavy metal pollution during the winter season, thus can be used to judge the quality of storm water flowing from streets. The major heavy metals found to have accumulated were lead, nickel, zinc and copper. These research results are useful for conducting preliminary evaluations of possible heavy metal pollution in other similar cities within the European Union. The general anthropogenic factor of three main types of land-use has the greatest influence on contamination of urban topsoil. In industrial sites, concentrations of key contaminants (Pb, Cu, Mn, Ni) are significantly higher than in residential and public–residential areas. The present article discussed the significance of systematic sustainable evaluation as one of the most important activities associated with a sustainable approach. Consequently, to reduce a negative effect of salts on street environment, measures of environmentally sustainable development have to be undertaken

Laboratory study of ammonium ion removal by using zeolite (clinoptilolite) to treat drinking water

Experimental investigation of ammonium ion removal from drinking water were carried out using natural zeolite (clinoptilolite) fractions of 0.3–0.6 mm and 0.6–1.5 mm. Before using natural zeolite was washed and dried in an oven at a temperature of about 105 °C. Solutions with different ion power (solution 1 ‐ supplied tap water and NH4Cl, solution 2 — distillate water and NH4Cl; initial concentration of ammonium ions of 2 mg/l) were filtrated through an experimental filter column packed with 70 mm and 210 mm of zeolite media for comparison purposes. Comparing the results for different natural zeolite fractions it was determined that the removal is more efficient using a finer fraction. After filtering 30 l of solution 1 through the laboratory‐ scaled filter column packed with 70 mm height of 0.3–0.6 mm particle size zeolite media and 0.6–1.5 mm particle size, the efficiency fluctuated from 89% to 70% (finer particles) and from 94% to 54% (coarser particles). Comparing the efficiency of ammonium ion removal from solutions with different ion power (solution 1 and solution 2), it was noticed that concentration reached the limit of 0.5 mg/l in the 12th l of solution 1, whereas it was fifty times lower in the 12th l of solution 2. After filtering 10 l of filtrate through the filter media with the height of 210 mm using coarse particles, the efficiency of ammonium ion removal reached 84%. Santrauka Eksperimentiniai NH4 + šalinimo laboratorijos salygomis iš ruošiamo geriamojo vandens tyrimai buvo atlikti naudojant gamtinio ceolito (klinoptilolito) 0,3–0,6 mm ir 0,6—1,5 mm stambumo frakcijas. Prieš naudojant gamtinis ceolitas buvo išplautas ir išdžiovintas krosnyje apie 105 °C temperatūroje. Pro eksperimentinio filtro ceolito užpildus (užpildo aukštis pirmuoju atveju buvo 70 mm, antruoju ‐ 210 mm) 5 m/h greičiu praleisti skirtingos jonines jegos tirpalai (iš vandentiekio vandens bei NH4Cl (I) ir iš distiliuoto vandens bei NH4Cl (II) pasigaminti tirpalai, kuriuose pradinD amonio jonu koncentracija buvo 2,0 mg/l). Lyginant dvieju skirtingu gamtinio ceolito frakciju eksperimento rezultatus nustatyta, kad smulkesne frakcija efektyviau iš tirpalu šalina NH4 +. Prafiltravus po 30 litru pirmojo tirpalo pro dvi 70 mm aukščio skirtingo ceolito grūdeliu stambumo frakcijas, amonio jonu šalinimo iš tirpalo efektyvumas kito atitinkamai nuo 89 % iki 70 % (esant smulkesnei frakcijai) ir nuo 94 % iki 54 % (kai frakcija stambesne). Lyginant amonio jonu šalinimo iš skirtingos jonines jegos tirpalu efektyvuma pastebeta, kad 0,5 mg/l amonio jonu koncentracija pirmojo tirpalo filtrate pasiekta jau dvyliktajame filtrato litre, o antrojo (II) tirpalo filtrato dvyliktajame litre ji buvo 50 kartu mažesne. Prafiltravus pro rege‐neruota 210 mm aukščio 0,6–1,5 mm stambumo ceolito grūdeliu užpilda 10 litru pirmojo tirpalo, amonio jonu šalinimo iš tirpalo efektyvumas sieke 84 %. Резюме Экспериментальные исследования очистки питьевой воды от ионов аммония проводились в лабораторных условиях, используя природный цеолит (клиноптилолит) с содержанием фракции 0,3–0,6 мм и 0,6–1,5 мм. Перед использованием природный цеолит был промыт и высушен в печи при температуре 105 0C. Растворы различного ионного заряда (1-й раствор из водопроводной воды и NH4Cl и 2-й раствор из дистиллированной воды и NH4Cl, в которых первичная концентрация ионов аммония была 2,0 мг/л) были пропущены через цеолитовую загрузку экспериментального фильтра со скоростью 5 м/ч (высота загрузки в первом случае составляла 70 мм, во втором – 210 мм). При сравнении результатов эксперимента с двумя различными фракциями природного цеолита обнаружено, что мелкозернистая фракция эффективнее очищает растворы от NH4+. После фильтрования 30 л первичного раствора обеими фракциями различной зернистости цеолита эффективность очистки раствора от ионов аммония достигала соответственно от 70% до 89% (мелкозернистой фракции) и от 54% до 94% (крупнозернистой фракции). При сравнении результатов удаления ионов аммония из 1-го и 2-го растворов с разными ионными зарядами в 12-м литре 1-го раствора была обнаружена концентрация ионов аммония в 0,5 мг/л, что в 50 раз меньше, чем в 12-м литре профильтрованного 2-го раствора. После того, как было профильтровано 10 л первого раствора через регенерированную цеолитовую загрузку высотой в 210 мм (фракция 0,6–1,5 мм), эффект очистки раствора от ионов аммония достигал 84 %. First Published Online: 14 Oct 2010 Reikšminiai žodžiai: amonio šalinimas, geriamasis vanduo, filtro užpildas, vandens ruošimas, ceolitas Ключевые слова: удаление аммония, питьевая вода, загрузка фильтра, водоподготовка, цеолит

A review of adsorbents used for storm water runoff cleaning (in Lithuanian)

Heavy metals, petroleum products, sediments and other pollutants get in the environment with insufficiently cleaned storm water runoff. Contaminated storm water runoff is one of the most significant sources for pollution in rivers, lakes and estuaries. Storm water runoff must be treated using not only simple methods but also using adsorption processes. Adsorbents can be natural organic, natural nonorganic and synthetic. Main adsorption characteristic, way of utilization and storm water runoff inflow rate, quantity and pollution need to be investigated when trying to use adsorbents in reasonably way. It is very important to treat storm water properly during the primary mechanical treatment otherwise adsorbents will act as mechanical filters. Article in Lithuanian. Adsorbentų, naudojamų paviršinėms nuotekoms valyti, apžvalga Santrauka. Į gamtinę aplinką su nepakankamai išvalytomis paviršinėmis nuotekomis patenka tokie teršalai, kaip sunkieji metalai, naftos produktai, skendinčios medžiagos ir kiti teršalai. Paviršinės nuotekos yra vienas iš pagrindinių ežerų, upių, vandens telkinių taršos šaltinių. Paviršinės nuotekos turi būti valomos ne tik įprastiniais metodais, bet ir taikant adsorbcijos procesus. Adsorbentai gali būti gamtiniai organiniai, gamtiniai neorganiniai ir sintetiniai. Siekiant tinkamai naudoti, svarbu žinoti pagrindines adsorbentų savybes, utilizavimo būdus, paviršinių nuotekų pritekėjimo intensyvumą, kiekį ir užterštumą. Labai svarbu gerai išvalyti paviršines nuotekas pirminio mechaninio valymo metu, kitaip adsorbentas veiks kaip mechaninis filtras.  Reikšminiai žodžiai: paviršinės nuotekos, adsorbcija, adsorbentai, užterštumas, gamtinė aplinka

Presence and fate of manganese substances in drinking water supply systems = Mangano junginiai ir jų sklaida geriamojo vandens tiekimo sistemose

Geriamąjį vandenį gali teršti daugelis medžiagų. Mikroteršalų sulaikymo galimybės vandentiekio sistemoje nėra visapusiškai ištirtos siekiant papildomai tausoti aplinką ir geriamąjį vandenį. Pasitelkus laboratorinį vandentiekio sistemos modelį buvo tiriami mangano šaltiniai, šio elemento buvimas bei potenciali pernaša ir nustatyti dideli vandens kokybės pokyčiai. Hidrocheminis modeliavimas rodo, kad vandens ruošimo metu mangano junginiai šalinami tik iki lygio, kurį nustato Europos Tarybos direktyvos reikalavimai mangano koncentracijai, ir tik maža jo dalis patenka į vandentiekio tinklą. Mangano junginiai yra atsparūs biologiniam skaidymui, todėl daugelis įprastinio požeminio vandens ruošimo įrenginių periodiškai tiekia vandenį su mangano likučiais į geriamojo vandens paskirstymo sistemą. Vandens ruošimas negali būti pripažintas patikimu mangano junginių sklaidos barjeru. Svarbu užtikrinti, kad tiekiant vandentiekiu geriamąjį vandenį kitos mangano šaltinių kontrolės priemonės (pvz., taikomos vamzdynų medžiagoms, mangano junginių sklaidai ir požeminio vandens kontrolei) būtų nuolat dėmesio centre ir kad mangano junginiai būtų efektyviai mažinami ir / ar šalinami, kaip to reikalauja Europos Tarybos direktyvos.A wide range of material sources may potentially contribute to contaminant loads in the potable water. The ability of water supply systems to act as emission control barriers for tap water micropollutants, thereby providing environmental benefits in addition to potable water savings, have not been fully explored. This paper investigates the sources, presence and potential fate of a selection of manganese micropollutants in laboratory scaled water supply systems. All of the investigated compounds are listed under the European Council Directive 98/83/EC on the quality of water intended for human consumption (1998) and World Health Or¬ganization Guidelines for Drinking-water Quality (2004). Significant water quality changes are identified. Hydro-chemical modelling indicates that the removal of manganese substances during water treatment is likely to be predominant due to the EC Directive manganese concentration requirement, with only minor contributions to the water supply network. Manganese compounds are resistant to biodegradation and the majority of conventional groundwater treatment plants periodically supply water with manganese residual to the potable water distribution system. Water treatment is unlikely to act as a comprehensive barrier for emission of manganese compounds. Hence, it is important to ensure that other manganese source control options (e. g. pipeline materials, manganese substance emission, and groundwater source control) for potable water supply continue to be pursued in order that emissions of manganese compounds from these sources are effectively reduced and / or phased out as required under the demands of the European Council Directive 98/83/EC on the quality of water intended for human consumption. DOI: http://dx.doi.org/10.6001/ekologija.v58i1.234

Development of a fluidised batch process using natural powdered zeolite (Clinoptilolite)

The purpose of this research was to examine water treatment improvement by using natural powdered zeolite (clinoptilolite). Experiments were carried out at a laboratory and in a pilot-scaled water treatment plant. The pilot-scaled plant was fed with groundwater containing a high level of organic compounds from the existing waterworks in Lithuania’s Neringa Region. The content of organic substances in the groundwater – characterized by chemical oxygen demand (COD), varied between 5.0 – 40.0 mg O2 1-1 and the permanganate index (oxidation by potassium permanganate) 4.0 – 8.0 mg O2 1-1 was determined during this case study. There was no significant reduction using conventional water treatment. Laboratory analysis of water quality showed: total iron, ammonium, aluminium residual concentrations, pH, colour (Pt scale), turbidity, COD and permanganate index. The drinking water had an undesirable colour, taste and odour due to high concentrations of organic substances in the groundwater. A fluidized batch process and adsorption of natural powdered zeolite were used for reducing organic substances in the water with the effectiveness of total iron concentration reduction by 96%. Experimental research results are included in the article

Analysis and evaluation of the effect of the solids from road surface runoff on the sediments of river bed = Automobilių kelių lietaus nuoplovų poveikio upės dugno nuosėdoms analizė ir vertinimas

Automobilių transporto sukeliama vandens telkinių tarša yra aktuali aplinkosaugos problema Lietuvoje. Siekiant ją išspręsti, vykdomi įvairūs moksliniai tyrimai ir eksperimentai, kuriais įvertinamas transporto intensyvumo šalia vandens telkinių esančiose gatvėse poveikis vandens kokybei bei dugno nuosėdų sankaupų susidarymui. Šiame straipsnyje, remiantis atliktais moksliniais tyrimais, analizuojama, kokį poveikį Šešupės upės atkarpai Marijampolėje turi dvi ją kertančios tarptautinės „Via Baltica“ magistralės atšakos. Tyrimų rezultatai rodo, kad miesto gatvėmis važiuojantis sunkusis transportas kelis kartus padidina teršalų kiekį gatvių lietaus nuoplovose. Tyrimų duomenimis, į Šešupę išleidžiamos gatvių lietaus nuotekos yra nepakankamai išvalomos, todėl kelia pavojų upės ekologinei būklei. Rekomenduojama lietingą rudenį riboti tranzitinio sunkiojo transporto eismą miestų gatvėmis nukreipiant jį aplinkkeliais ir taip mažinant gatvių teršalų patekimą į vandenį. DOI: http://dx.doi.org/10.6001/ekologija.v57i1.130

Experimental Research on Quality Parameters of Recycled Concrete

Concrete itself, and issues relating to the recycling and management of reinforced concrete waste, are highly relevant, especially when urban expansion is being achieved by increased building construction volumes. This research investigates concrete waste and its (re)usage possibilities and resolves several major issues related to the question of how natural materials can be replaced by compounds made from concrete waste, thereby saving natural resources. The experiment was carried out using concrete mixtures, which were combined with natural aggregates and crushed concrete waste (fraction 4/16). The resulting mix of concrete was achieved using natural aggregates, thus replacing natural aggregates with waste, which had partially and fully replaced bulky aggregates with crushed concrete waste. The main aim of the investigation was to investigate how aggregates made from crushed concrete waste impact the properties of concrete. The exothermic effect on the concrete mixture during the hardening process was investigated. Furthermore, a macrostructural analysis of hardened concrete was conducted using scanned sample images; the adhesion zone between newly formed concrete stone and aggregates derived from natural rock from crushed concrete waste was investigated. Using an electron microscope to observe aggregate from crushed concrete waste and the contact zone of hardened cement stone revealed that the aggregate from waste adheres poorly with hardened cement stone. Furthermore, both the mechanical properties of new, hardened concrete and determined resistance to frost indicators are weak. Concrete density and compression strength decreased (by up to 8% and up to 18%, respectively), and absorption increased almost twofold due to aggregates derived from crushed concrete waste, since their cleavage strength indicator was twice as high, while water absorption was four times higher than that of natural aggregate. The results indicate that recycled concrete obtained from demolished buildings is environmentally sustainable and can be recommended for lower quality concrete for use in related engineering projects.This article belongs to the Special Issue Research of Structure and Properties of Concretes Based on Non-conventional Aggregate