The essence of the contemporary mathematical modelling methodology is the replacement of a real object in question (a process, phenomenon or system) with its "image" - a mathematical model. The ...mathematical modelling programme REC (Risk Reduction, Environmental Merit and Cost) is based on the comparison of alternative cleaning technologies (to clean contaminated areas). The programme REC is aimed at adapting efficient soil decontamination technologies. The aim of this paper is to analyse the ability of a grassy vegetation mixture to absorb heavy metals from soil in this way decontaminating it. Initial concentrations of heavy metals (copper, lead, manganese, zinc, nickel and chromium) - the concentrations, used during the experiment when performing the investigation into the efficiency of soil remediation using the mixture of grassy vegetation, were input into the programme. During the entire chosen period of 10 years, soil would be decontaminated from copper and lead. The zero concentration of manganese in soil is achieved after 8 years, and that of zinc - after 9 years when soil is cleaned with the mixture of grassy vegetation and no additional contamination is present. Soil is most rapidly decontaminated from nickel - in 6 years. At the initial chromium concentration of 79.5 mg/kg in soil, the zero concentration of this metal would be achieved in 7 years.
Millions of tons of different organic waste form in the world every year, but only a little part of waste is suitable for biogas production, while its rest part can't be used for biogas production ...because of different reasons and is utilized using other methods or deposited in landfills. Organic waste, produced in our country, is mixed very often with different kinds of municipal or industrial waste. For a successful use of anaerobic organic waste treatment technologies, a maximal decrease of its harmful effect on the environment, and reaching of a maximum economic efficiency, it is necessary to sort organic waste (or better, not to mix it with other inorganic waste from the very start). Experimental investigation with fruit, vegetable and meat waste are presented in the paper. The aim of the investigation was to observe the concentrations of released methane and oxygen gases as well as to measure temperature changes.
Heavy metals, such as lead, chromium, zinc, cadmium and cooper may cause hazardous harm to human health and the environment because of their dissolubility and mobility. Selection of the most ...appropriate soil remediation method depends on site characteristics, concentration, types of pollutants to be removed and the final use of a contaminated medium. This paper reviews soil remediation technologies, such as isolation and containment, solidification/ stabilization technologies, soil washing and flushing technologies, electrokinetics and phytoremediation.
Heavy metals, such as lead, chromium, zinc, cadmium and cooper may cause hazardous harm to human health and the environment because of their dissolubility and mobility. Selection of the most ...appropriate soil remediation method depends on site characteristics, concentration, types of pollutants to be removed and the final use of a contaminated medium. This paper reviews soil remediation technologies, such as isolation and containment, solidification/ stabilization technologies, soil washing and flushing technologies, electrokinetics and phytoremediation.
Pasaulyje kasmet susidaro milijonai tonu ivairiausiu organiniu atlieku. Tačiau bioduju gamybai tinka tik tam tikra ju dalis, kita dalis del ivairiu priežasčiu negali būti panaudota biodujoms gaminti ...ir yra ivairiais metodais utilizuojama arba kaupiama savartynuose. Mūsu šalyje susidarančios organines atliekos dažnai yra sumaišomos su kalnais ivairiausiu kitos rūšies buitiniu bei gamybiniu atlieku. Todel, norint sekmingai pritaikyti anaerobinio organiniu atlieku apdorojimo technologijas ir kuo labiau sumažinti šiu atlieku kenksminga poveiki aplinkai bei gauti didžiausia ekonomini efektyvuma, šias atliekas būtina rūšiuoti (geriausia iš pat pradžiu ju nesumaišyti su kitomis atliekomis). Aprašomi eksperimentiniai tyrimai su vaisiu, daržoviu ir mesos atliekomis, atlikti jas sluoksniuojant su pjuvenomis ir keramzitu. Eksperimento metu stebimos išsiskiriančio metano bei deguonies koncentracijos ir fiksuojami temperatūru pokyčiai talpyklose. Nustatyta, kad biodegradacijos procesas leteja atliekas sluoksniuojant su keramzitu.
The essence of the contemporary mathematical modelling methodology is the replacement of a real object in question (a process, phenomenon or system) with its “image” ‐ a mathematical model. The ...mathematical modelling programme REC (Risk Reduction, Environmental Merit and Cost) is based on the comparison of alternative cleaning technologies (to clean contaminated areas). The programme REC is aimed at adapting efficient soil decontamination technologies. The aim of this paper is to analyse the ability of a grassy vegetation mixture to absorb heavy metals from soil in this way decontaminating it. Initial concentrations of heavy metals (copper, lead, manganese, zinc, nickel and chromium) ‐ the concentrations, used during the experiment when performing the investigation into the efficiency of soil remediation using the mixture of grassy vegetation, were input into the programme. During the entire chosen period of 10 years, soil would be decontaminated from copper and lead. The zero concentration of manganese in soil is achieved after 8 years, and that of zinc ‐ after 9 years when soil is cleaned with the mixture of grassy vegetation and no additional contamination is present. Soil is most rapidly decontaminated from nickel ‐ in 6 years. At the initial chromium concentration of 79.5 mg/kg in soil, the zero concentration of this metal would be achieved in 7 years. Santrauka Matematinio modeliavimo metodologijos esmė yra tiriamo realaus objekto (proceso, reiškinio, sistemos) pakeitimas jo „atvaizdu“ – matematiniu modeliu. Matematinio modeliavimo programa REC (angl. Risk reduction, Environmental merit and Cost) pagrįsta alternatyvių valymo technologijų (užterštam plotui valyti) lyginimu. Programos REC tikslas – pritaikyti efektyvias ir veiksmingas dirvožemio valymo technologijas. Šio darbo tikslas – išanalizuoti žolinės augalijos mišinio gebą sorbuoti sunkiuosius metalus iš dirvožemio ir tokiu būdu valyti iš jo teršalus. Programoje nusistatomos pradinės sunkiųjų metalų (vario, švino, mangano, cinko, nikelio ir chromo) koncentracijos, eksperimentų metu naudotos tiriant dirvožemio kokybės atkūrimo žolinės augalijos mišiniu efektyvumą. Iš esmės per visą pasirinktą laikotarpį – 10 metų iš dirvožemio būtų valomas varis ir švinas. Mangano nulinė koncentracija dirvožemyje, valant jį žolinės augalijos mišiniu ir nesant papildomo teršimo, pasiekiama po 8 metų, cinko – po 9 metų. Greičiausiai iš dirvožemio išvalomas nikelis – per 6 metus. Chromas, esant 79,5 mg/kg pradinei jo koncentracijai dirvožemyje, iki nulinės koncentracijos būtų išvalytas per 7 metus. Резюме Суть методологии математического моделирования заключается в замене исследуемого реального объекта (процесса, явления, системы) его отображением – математической моделью. Программа математического моделирования REC (aнгл. Risk reduction, Environmental merit and Cost) основана на сравнении альтернативных технологий по очищению загрязненных территорий. Целью программы REC является приспособление эффективных и действенных технологий для очищения почв, а целью настоящей работы – анализ способности смеси из травянистых растений сорбировать тяжелые металлы из почвы и таким образом способствовать ее очищению от загрязнителей. По программе задаются начальные концентрации тяжелых металлов (меди, свинца, марганца, цинка, никеля и хрома), применявшиеся во время экспериментальных исследований эффективности восстановления качества почв благодаря применению смеси из травянистых растений. Практически за весь установленный промежуток времени – 10 лет – почвы будут очищены от меди и свинца. При очищении почв с помощью смеси травянистых растений и при отсутствии дополнительного загрязнения нулевая концентрация марганца достигается спустя 8 лет, цинка – 9 лет. От никеля почва очищается спустя 6 лет, а от хрома при начальной его концентрации в почве, равной 79,5 мг/кг, спустя 7 лет.
Nūdienos pasaulyje didejant žmoniu skaičiui dideja ir susidarančiu atlieku kiekiai. Nerūšiuotos komunalines atliekos patenka i eksploatuojamus savartynus. Savartyno neigiama poveiki aplinkai lemia ne ...tik pačios atliekos, bet ir iš ju sklindančios dujos, užterštos nuotekos. Dauguma savartynu neatitinka net elementariu aplinkos apsaugos ir sanitariniu-higieniniu reikalavimu, pavyzdžiui, savartynuose neirengta filtrato surinkimo sistema. Atlieku tvarkymas Lietuvoje kelia daug rūpesčiu. Komunaliniu atlieku surinkimo sistemos neefektyvios, iranga nusidevejusi. Daugybe atlieku, kurios galetu būti panaudotos kaip antrines žaliavos, patenka i savartynus sumaišytos su kitomis atliekomis. Norint pritaikyti anaerobinio organiniu atlieku apdorojimo technologijas ir kuo labiau sumažinti kenksminga poveiki aplinkai, atliekas būtina rūšiuoti. Straipsnyje pateikiami eksperimentiniu tyrimu su vaisiu, daržoviu ir mesos atliekomis, didinant ju dregni - iki 75 %, 79 % ir 85 %, rezultatai. Eksperimento metu, kurio trukme 60 paru, stebetos išsiskiriančio metano bei deguonies koncentracijos, fiksuoti temperatūru pokyčiai talpyklose. Atlikus eksperimenta nustatyta, kad 50 litru talpyklose su ivairiomis atliekomis, atlieku dregni padidinus iki 85 %, išsiskiriančio metano esti daugiau nei talpyklose, kuriose dregmes kiekis mažesnis.
The today's world faces a rapid increase of population and thus a growing amount of generated waste. Unsorted municipal waste is transported to landfills. The negative environmental impact of a ...landfill is related with generated odours, polluted leachate and waste itself. Most of present landfills do not meet minimal environmental and sanitary requirements, i e most of landfills do not have an installed leachate collection system. In Lithuania waste management is related with many problems. The municipal waste collection system is inefficient, and the equipment is outdated. Large amounts of recyclable waste materials mixed with other wastes are still disposed in landfills. Aiming to use anaerobic digestion technologies for organic waste and minimize their negative environmental impact, recyclables need to be separated. The paper gives information about experimental investigation with fruit, vegetable and meat waste humidified with addition of moisture to 75 %, 79 % and 85 %. The experiment lasted for 60 days, and the concentration of methane and oxygen as well as temperature changes in vessels were observed. The results showed that in 50 l containers of mixed waste set with moisture to 85 % higher amounts of methane were produced than in those humidified with less water.
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