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Spent portable batteries belong to the category of hazardous waste, sometimes dumped together with non-hazardous municipal waste in landfills, resulting in various aquatic environments. Their presence in the aquatic environment leads to changes in its quality and its contamination with heavy metals or other toxic elements. This paper highlights the portable battery waste's influence on the aquatic environment in stagnant conditions. Therefore, three types of batteries and three solutions with different pH values were used to represent the possible media existing in nature: acid (pH = 4.00), rainwater (pH = 5.63), and alkaline (pH = 8.00). After 180 days, the results showed changes in the chromatics and composition of the initial solutions. The analyses showed decreased pH, increased conductivity, and the transfer of several heavy metals into solutions (Cu, Pb, Zn, Ni, and Fe). Thus, there were slight exceedances of the maximum allowed values for water quality class I (Order no. 161/2006) in the case of Cu and Pb and higher exceedances in the case of Zn, Ni, and Fe. Zinc–carbon batteries stand out because of the release of Pb and Fe ions. The same applies to lithium manganese dioxide batteries because of Ni ions as well as zinc–manganese alloy batteries because of Cu and Zn ions. Altogether, the negative influence of spent batteries on the aquatic environment is noticed, and the measures for the implementation of safe disposal and processing are necessary. [ABSTRACT FROM AUTHOR]

The problem of global warming and the reduction of energy consumption have led to an evolutionary progress of research directed towards finding as many solutions as possible to these environmental issues. Firstly, this paper presents the background information on the role of wastewater as a source of heat for the future. Next, the paper includes the analysis elements that define a system for recovering thermal energy from wastewater. The main objective was to identify the parameters that determine the heat transfer. It has started from a conceptual model of the technological system that involves inputs and outputs characterized by technological, physical-chemical, measurable or imposed properties. In the second part this paper presents a numerical model elaborated for the analysis and simulation of the main physical processes, the mass and heat transfer, which underlie the operation of the heat pipe heat exchangers (HPHE). The numerical simulation of heat and mass transfer in the HPHE is computed by using Delphi 7 solver program. This program contained a series of sub-programs for the meshing of the field occupied by the HPHE, another subprogram for solving the meshing equations and the third for post processing. The design of HPHE is the key to provide a heat exchanger system to work proficient as expected. Finally, the result is used to optimize and improving heat recovery systems of the increasing demand for energy efficiency in residential buildings or industry.

The use of waste from industrial activities is of particular importance for environmental protection. Fly ash has a high potential in the production of construction materials. In the present study, the use of fly ash in the production of geopolymer paste and the effect of Fe2O3, MgO and molarity of NaOH solution on the mechanical strength of geopolymer paste are presented. Samples resulting from the heat treatment of the geopolymer paste were subjected to mechanical tests and SEM, EDS and XRD analyses. Samples were obtained using 6 molar and 8 molar NaOH solution with and without the addition of Fe2O3 and MgO. Samples obtained using a 6 molar NaOH solution where Fe2O3 and MgO were added had higher mechanical strengths compared to the other samples. [ABSTRACT FROM AUTHOR]

Currently, soil pollution is a critical environmental problem that concerned all humanity due to its impact on ecological environment and human health. In order to remediate the contaminated soils, some technologies, generally based on physical, chemical, thermal, and biological processes, have long been in use. However, effectiveness of these methods depends considerably on soil type and characteristics, level of pollution and mixed contaminants present in soil. Therefore, in the present study, the pedological properties of the soil collected from abandoned mining perimeter of "Larga de Sus" from Zlatna (Alba County, Romania) were investigated in order to choose the most appropriate method for soil remediation and establish the parameters of soil remediation technology. The results indicated that soil in the area is highly acidic which favors the mobility of heavy metals in soil and other environmental components. On the other hand, most of the samples are partially structured and poorly structured while some samples are well structured, very poorly structured, or present a lack of aggregates structure. Also, the coarse sandy and loam-sandy texture of the samples was identified. Thus, considering soil properties, soil washing technology may be the appropriate remediation technology for contaminated soil in the studied area considering costs and efficiency. [ABSTRACT FROM AUTHOR]

Heavy metal contamination of soils is a widespread environmental problem associated with mining operations and has drawn considerable study interest, due to its impact on ecological environment. The present study consisted in the determination of heavy metals concentration in the soils nearby "Larga de Sus" mine (Zlatna mining perimeter, Romania). Thus, the concentration of Pb, Cu, Cr, Zn and Cd in twenty soil samples collected from ten soil sampling sites was determined by atomic absorption spectrometry. In spite of the fact that mining activity is nowadays completely stopped, the results of the chemical analysis indicated that the soil in the study area is still highly polluted with Pb since the identified concentrations of Pb (10.4-3136.0 mg/kg) in soil exceeds the intervention threshold limits established by the Romanian legislation in most of the samples collected. [ABSTRACT FROM AUTHOR]

The effect of three humic washing solution pH values (3.0, 7.0 and 9.6-its natural pH) on the removal efficiency of Pb and Cu from multimetal contaminated soil collected nearby "Larga de Sus" mine from Zlatna (Alba County, Romania) was investigated, at laboratory scale, by an ex-situ soil washing technique. In this study, a commercial soluble humic sample extracted from German Leonardite was used as washing agent to remove Pb and Cu from polluted soil. Soil washing experiments were conducted in a stirrer with orbital-rotation oscillation at a liquid/solid ratio (L/S ratio; mL:g) of 8:1, concentration of humic washing solution of 2% and various stirring times (4, 6, 12, 24 and 40 hours). The removal efficiency of Cu and Pb increased with increasing pH from 3.0 to 9.6. In investigated experimental conditions, the best removal efficiencies (60.3% in case of Cu and 48.08% in case of Pb) were obtained at alkaline pH values of humic washing solution. [ABSTRACT FROM AUTHOR]

The most important contaminated areas from Cluj County are the uncontrolled HCH scrap deposits from Turda city, which appeared as a result of the industrial activity of the former Chemical Plant Turda. Over the years, were identified 4 locations in the area. The four contaminated locations situated in the area of Turda city Sum up to 60000 tons of HCH polluted soil are. One of these zones is the Posta Rat area (40000 m2) which is situated on the left bank of Aries River. The objective of this paper is to carry out experimental researches in order to establish the physical-chemical properties of the soil from Posta Rat area, soil contaminated with HCH (hexachlorocyclohexane). The texture, structure, humidity and pH are the main analysis performed in order to determine the optimum cleaning technologies for the deteriorated soil as a result of the activity of the Chemical Plant in Turda. The results of the physical-chemical analysis can point out the most suitable cleaning soil solution, because as a result of the study, the characteristics of the soil are known, being much easier to identify the applicability limits of the cleaning solutions. [ABSTRACT FROM AUTHOR]

Pollution has become an issue of current concern for all humanity, because of the negative impact on the environment and human health. One of the most affected by environmental factors due to human activities is the soil, which is a sponge for contaminants. Soil contamination with heavy metals presents a major concern both global and national levels, in order to control resulted pollutants from industrial activities and finding different methods of eco-friendly and effective remedy. In the present paper is presented the Haneş mine area, the soil from here being very acid due to mining activities performed in the past. [ABSTRACT FROM AUTHOR]

The present study consisted in the determination of lead concentrations in soil samples and sterile material dumped collected from the Almaşu Mare mining area. The lead concentration in the samples collected were determined by atomic adsorption spectrometry (AAS). In spite of the fact that all mines from area are nowadays inactive, the results of the chemical analysis showed that the soils in the area are still highly polluted with lead, except at the base of the "Radeş" dump, where the lead concentrations were below the intervention thresholds. [ABSTRACT FROM AUTHOR]

The gold mining activity performed in the past in Romania has led to the pollution of the environment, the degradation of large areas of land and currently represents a significant risk to human health. As a result of the gold mining activities performed in Almasu Mare area, there were large sterile dumps and gold mine galleries that continue to give their mark on the quality of the environment and human health through the amount of heavy metals in the soil and the sterile material improperly deposited, the water that comes out of the underground to the contaminated surface and which flows into the rivers in an uncontrolled way. This paper brings details of cadmium soil pollution in the studied area. The results obtained in the analysis of cadmium concentrations through the AAS spectrometry show that the analysed soil exceeds the admissible limits provided by the legislation in force, and the sterile material collected from the sterile dumps reflects values of the Cd concentration in the interval 10.7 - 22.6 mg/kg. Due to the high concentrations present in the soil and sterile material analysed, soil remediation interventions are required in the area. [ABSTRACT FROM AUTHOR]

The current paper presents the method that designs, manufactures and tests antimony based pH sensor used for monitoring of soil pH. In the first stage of this work the method of manufacturing the sensitive antimony elements is presented. These sensitive elements are casted into different forms (conical and cylindrical). These are subjected to a series of analysis in order to determine the chemical composition of the material used 99.73% Sb, 0.27% Ti (EDX), the morphology of the structure (SEM) and the characteristics of the oxide layer (XRD). The second part of this paper explains the method of testing the manufactured antimony sensors in the reference pH solutions. Finally, the sensors are used for measurements and are tested, alternatively, in pairs, with a reference Ag/AgCl sensors found in commerce. The results of these measurements show values approximately identical at both manufactured sensors. The adapted sensor that was obtained shows a relatively fast and stable response to pH changes in aqueous solutions. Its potential has a linear relation with pH solutions and a slope of 50.95 mV/pH. [ABSTRACT FROM AUTHOR]

Past mining activities in the Almasu Mare area have led, along the time, to environmental pollution, especially of the soil. Rades gold mine is a source of negative impact today. The improperly mine closure gives the possibility of the leaks from the inside of mine to arrive at surface, creating large imbalances in soil and not only. Also, the sterile dump which is very near of Rades mine is a concern for the environment from Almasu Mare because it is not subject to ecological coating process, and the wind and rain can lead the particulates on the surface of the dump at long distances. In order to analyse the current situation of soil in Rades mine area some physico-chemical analysis were performed. The physico-chemical analysis consisted in determination of the humidity content, the structure, texture and pH of the soil. The results of experiments related to the humidity showed that the soil humidity in the forest (18.34%-34.77%) was higher than the humidity determined from the surface tailings of Rades dump (14.15% - 22.39%). The soil in forest area is partially structured and the dump material is poorly or very poorly structured. The dump material and soil texture is largely rough and the pH of tailings material taken from the Rades dump surface was in the range of 3.4-4.8 pH units and in the forest was in the range of 5.3-5.6 pH units. [ABSTRACT FROM AUTHOR]

The non-ferrous metallurgical activities led to the pollution of large areas of soil and affected the environment in a negative way. The problems generated by soil contamination with different pollutant substances have been, in the latest period in the center of attention for researchers from all around the world. The objective of this paper is to perform experimental researches in order to establish the physical-chemical properties of the soil from Copsa Mica area. The texture, structure, humidity and pH are the main analysis performed in order to proper establish the optimal soil cleaning technologies. In order to establish the actual pollution degree in the moment of soil sampling, was determined also the concentration of metals in the soil. For this purpose, were taken soil samples from two areas on three depth interval (0-40 cm). Determining the concentration of heavy metals on three depth levels offers the researcher a relevant view of the historical pollution of the area under study. As a result of these researches was established that the soil is polluted with Pb, Zn and Cd. The quantity on metals in the soil is way beyond the alert threshold. As a conclusion these soil need cleaning, which can be made through various methods, one of the being bioleaching, which is a biological cleaning method which implies using microorganisms in order to favor leaching and heavy metals extraction from the polluted soils. [ABSTRACT FROM AUTHOR]

Contaminated soils from former industrial sites need urgent measures of treatment in order to be used for other purposes. Because of the large spaces that industrial sites usually occupy, green technologies have to be chosen to treat the soil while protecting the environment. Phytoremediation is an environmentally friendly technology that uses plants to decontaminate soils. The main advantage is the low cost compared to other techniques and the main disadvantage is the time factor because phytoremediation requires long period of time to treat the polluted soil. This paper presents specific features that must be taken into consideration when planning and implementing phytoremediation projects. Pollutants concentration and soil properties limit the application of phytoremediation. A clean-up plan is prepared taking into consideration limiting factors and then the remediation measures are implemented. The project needs long-term monitoring to determine the quantity of contaminants in soils during its implementation. The main purpose is to provide a safe environment for humans' health while improving the ecological situation of the former industrial sites. [ABSTRACT FROM AUTHOR]

The influence of aeration of soils polluted with heavy metals by using Thiobacillus-type microorganisms was studied using soil samples contaminated with heavy metals (Cu 4074 - 7550 mgkg-1, Zn 5870 - 9310 mgkg-1, Cd 36-50 mgkg-1, Pb 15000 - 42890 mgkg-1), from Romplumb, Baia Mare. The variation of the metal concentration extracted by bioleaching and aerated bioleaching was monitored for 16 weeks. The soil samples treated by bioleaching (Cu: 9 - 53%; Zn: 9 - 62%; Cd: 9 - 24%. Pb: 31 - 71%) have obtained a lower efficiency than the soil samples treated by aerated bioleaching (Cu: 34 - 70%; Zn: 36 - 76%; Cd: 17 - 38%. Pb: 44 - 78%), but there are percentage differences between the two processes (Cu: 17 - 27%; Zn: 14 - 27%; Cd: 8 - 14%, Pb: 7 - 13%). [ABSTRACT FROM AUTHOR]

In this paper are presented preliminary studies regarding the utilization of microorganisms for the decontamination of soils polluted with heavy metals. The concentration of heavy metals was determined by inductive coupled plasma atomic emission spectroscopy (ICP-AES). It has been confirmed that the studied area is polluted with Zn, Pb, Cr, Fe, Cu, Cd, Mn, the concentrations exceeding in most cases the alert threshold and the intervention threshold. The experiments led to the conclusion that this area needs reclaiming which can be done by bioleaching. This is a biologic treatment method, which uses microorganisms to encourage the solubility and the extraction of heavy metals from polluted soils. [ABSTRACT FROM AUTHOR]