TREATMENT OF WASTEWATER FROM SEPARATORS FOR RAINFALL RUNOFF USING ELECTROCHEMICAL OXIDATION PROCESSES

In recent years, industry has increased and with it the amount of oily wastewater, which are considered hazardous waste because they contain various types of heavy metals and oils that endanger the environment and human health. In the last twenty years, there has been increased research on new technologies to treat wastewater as efficiently and environmentally friendly as possible. A recent approach to wastewater treatment is the application of electrochemical processes such as the electro-Fenton process, which belongs to the group of electrochemical advanced oxidation processes and electrocoagulation. The aim of this work was to remove organic contaminants and heavy metals from wastewater originating from oil and grease separators that clean stormwater runoff from traffic areas. The use of stainless steel, iron and aluminum electrodes results in electrooxidation, electroreduction and electrocoagulation. At a current of 15 A the treatment efficiency was 50% for COD and 73% for mineral oil. At a current of 110 A the treatment efficiency was 96% for COD and 90% for mineral oil

LCA of heavy metals leaching from landfilled sewage sludge ash

Quantities of sewage sludge that are thermally treated (mostly incinerated) are increasing, resulting in growing quantities of sewage sludge ash (SSA) which also requires further management. Despite its potential as a resource, it is still largely landfilled. Considering the presence of potentially toxic and hazardous heavy metals in SSA, this paper analyzes how the change in the leaching concentrations of the selected heavy metals from landfilled SSA impacts the environment (air, water, and soil) by the means of LCA. When considering human toxicity potential as impact category, dominant impacts were due to emissions into the air, primarily caused by leaching of selenium and somewhat less cadmium, mercury and nickel. Mercury had a dominant impact when considering the terrestrial ecotoxicity potential impact. In the SSAs obtained from Croatian sludge, molybdenum leaching, along with selenium and mercury, showed a dominant impact. Therefore, due to the high variability of trace elements, detailed analysis of different SSAs is needed

POSTIZANJE RESURSNE UČINKOVITOSTI OBJEDINJAVANJEM SEKTORA ENERGETIKE, VODE I OTPADA

Current economic growth and the presently deployed technology result in high entropic cost for the planet. Resource efficiency considers using the Earth’s limited resources in a sustainable manner while minimising impacts on the environment. Paper presents the concepts of entropy and circular economy, and elaborates on waste, energy/nutrients and water nexus. Integrating the energy, water and waste sectors is indispensable for achieving resource efficiency. The Republic of Croatia should endeavour to benefit from this strategy to conserve its ecosystems and natural capital. Moreover, resource efficiency achievement can generate substantial benefits which include reduced landfill and carbon emissions, higher rates of re-use and recycling of products and greater job creation.Sadašnji gospodarski razvitak i prevladavajuća tehnologija uzrokuju visok entropijski trošak za planet. Resursna učinkovitost podrazumijeva korištenje ograničenih resursa ovog planeta na održiv način kako bi se smanjio čovjekov utjecaj na okoliš. Rad daje prikaz pojma entropije i kružnog gospodarstva te obrađuje poveznicu između otpada, energije/hranjivih tvari i vode. Objedinjavanje sektora energije, vode i otpada je nužno za postizanje resursne učinkovitosti. Republika Hrvatska treba nastojati izvući korist iz opisane strategije kako bi sačuvala svoje ekosustave i prirodni kapital. Nadalje, postizanje resursne učinkovitosti može značajno pridonijeti smanjenju emisija, povećanom stupnju oporabe i recikliranja proizvoda kao i stvaranju novih radnih mjesta

The Influence of Selected Parameters on the Inclination of the Maxillary Permanent Canine during Eruption

Gornjem očnjaku, što se anatomskoga položaja u čeljusti tiče, te funkcijskih i estetskih karakteristika, pripada posebno mjesto u ravnoteži stomatognatog sustava. U ovome se je radu željelo ispitati ispravljanje očnjaka tijekom nicanja, te učinak meziodistalnog promjera krune gornjega postra- ničnog sjekutiča, širine aperture piriformis, te indeksa glave i lica u tome procesu. Uzorak je obuhvaćao ortopantomograme 600 ispitanika u dobi od 7-12 godina. Iz rezultata proizlazi da kut inklinacije maksilarnog očnjaka raste s porastom dobi, te da je veći u djevojčica. Učinak meziodistalne dimenzije gornjega postraničnog sjekutiča na inklinaciju očnjaka nađena je samo na lijevoj strani čeljusti. Nije nađena povezanost inklinacije očnjaka s ostalim ispitivanim parametrima.Due to its anatomic position in the jaw, and its functional and aesthetic characteristics, the upper canine plays a significant role in the equilibrium of the stomatognathic system.. The aim of this study was to investigate the straightening of the inclination of the canine during eruption and the influence of the mesiodistal dimension of crowns of the upper lateral incisors, of the distance between apertura piriformis and facial and head indexes in this process. The sample consisted of 600 orthopanthomograms of subjects aged between 7 and 12 years. The results showed that the angle of the maxillary canines inclination increased with age, and that was greater in girls than in boys. The influence of the mesiodistal diameter of lateral maxillary incisors on inclination angle was found only on the left side. No connection was found between change in the inclination angle and other examined variables

BIODEGRADATION OF AZO DYE BY ADAPTED MIXED MICROBIAL CULTURES

Wastewater effluents from azo dye production and other dye-stuff using industries contain significant amounts of highly resistant azo dyes that require special treatment processes to prevent groundwater contamination. The present study is based on the approach of aerobic followed by anaerobic step for biodegradation and decolorization of azo dye. The main objective of this work was the adaptation, isolation and preparation of mixed microbial culture, from laboratory collection, catabolically able to biodegrade under aerobic conditions bordo azo dye present in mother lye after industrial production of that dye. The anaerobic step needed for biodegradation of azo dye was performed by the use of adapted active anaerobic sludge from a wastewater treatment plant of the sugar industry. The adapted aerobic and anaerobic microbial cultures demonstrated significant biodegradative enzymatic potential and can be further used for development of a continuous aerobic – anaerobic process for the treatment of wastewater from industrial production of azo dye

THE NEED FOR INTEGRATED APPROACH TO ENVIRONMENTAL PROTECTION IN THE REPUBLIC OF CROATIA

It is a well-known fact that healthy environment is a basic prerequisite for preserving people’s health and quality of life. Various symptoms of environmental crisis, perceptible worldwide in their various forms, are giving a clear warning that current civilization development patterns, unless significant changes and reversals occur, are unsustainable. The paper gives an overview of actual national state of the environment. It is pointed out that institutions whose competence involves the management of particular segments of the environment are insufficiently interconnected, and thus against insufficiently developed environmental awareness and the prevailing adverse economic conditions, render difficult any positive development with regard to restoring to measures for recovery and improvement aimed at preserving good quality of the environment. It is furthermore pointed out that rational and in the long-term efficient environmental protection at national level may be achieved and maintained only if considering the state of environment in its integrity, and by taking the measures and implementing the solutions based on an interdisciplinary expert approach accompanied by holistic management. In order to increase the efficiency of environmental protection, it is certainly indispensable to achieve inter-institutional integration and action while considering and contemplating individual environmental components as an integral corpus - indivisible ecosystem

APPLICATION OF NATURAL ZEOLITES IN ENVIRONMENT PROTECTION

U ovome radu sažeta su istraživanja i vlastita iskustva o mogućnosti iskorištavanja svojstava prirodnog zeolita kod završnog stupnja obrade vode za uklanjanje tragova metalnih iona kao kroma, srebra i arsena. Arsen prisutan u prirodnim vodama je genetskog podrijetla zbog procesa razlaganja minerala kojim prolaze podzemne vode. Ostali ispitivani metalni ioni su uglavnom antropogenog podrijetla zbog utjecaja kemijske, tekstilne i metalurške industrije. Rezultati istraživanja pokazali su da je efikasnost uklanjanja arsenovih iona na željezom modificiranim zeolitima za niže koncentracijsko područje do 100 %, kromovih iona za koncentracijsko područje 0,5-20 mg/L od 40 do 60 % ovisno o modifikaciji zeolita, a srebrovih iona za koncentracijsko područje 5-120 mg/L od 55 do 70 % ovisno o nalazištu prirodnog zeolita.The paper summarizes the findings and our own experience regarding exploitation of the properties of natural zeolite in the final processing of water to remove traces of metal ions like chromium, arsenic and silver. Arsenic present in natural waters is of genetic origin and is due to the process of decomposition of minerals in groundwater. Other examined metal ions are mainly of anthropogenic origin and come from the chemical, textile and metallurgical industries. The results showed that the efficiency of arsenic removal using iron modified zeolites for the lower concentration range is up to 100%, for chromium ions in concentration range from 0.5 to 20 mg/L is 40 to 60% depending on the modification of zeolites, and for silver ions in concentration range from 5-120 mg/L from 55 to 70% depending on the deposit of the natural zeolite

Bathymetric Survey of the St. Anthony Channel (Croatia) Using Multibeam Echosounders (MBES)—A New Methodological Semi-Automatic Approach of Point Cloud Post-Processing

Multibeam echosounders (MBES) have become a valuable tool for underwater floor mapping. However, MBES data are often loaded with different measurement errors. This study presents a new user-friendly and methodological semi-automatic approach of point cloud post-processing error removal. The St. Anthony Channel (Croatia) was selected as the research area because it is regarded as one of the most demanding sea or river passages in the world and it is protected as a significant landscape by the Šibenik-Knin County. The two main objectives of this study, conducted within the Interreg Italy–Croatia PEPSEA project, were to: (a) propose a methodological framework that would enable the easier and user-friendly identification and removal of the errors in MBES data; (b) create a high-resolution integral model (MBES and UAV data) of the St. Anthony Channel for maritime safety and tourism promotion purposes. A hydrographic survey of the channel was carried out using WASSP S3 MBES while UAV photogrammetry was performed using Matrice 210 RTK V2. The proposed semi-automatic post-processing of the MBES acquired point cloud was completed in the Open Source CloudCompare software following five steps in which various point filtering methods were used. The reduction percentage in points after the denoising process was 14.11%. Our results provided: (a) a new user-friendly methodological framework for MBES point filtering; (b) a detailed bathymetric map of the St. Anthony Channel with a spatial resolution of 50 cm; and (c) the first integral (MBES and UAV) high-resolution model of the St. Anthony Channel. The generated models can primarily be used for maritime safety and tourism promotion purposes. In future research, ground-truthing methods (e.g., ROVs) will be used to validate the generated models