METALS AND ORGANIC POLLUTANTS REMOVAL FROM WASTEWATER BY LOCAL LEMNA MINOR GENOTYPE

Lemna minor was collected from a local pond from the Floresti area, Cluj county. The plants were left for vegetative multiplication, and then analyzed in order to investigate their ability to reduce the pollutants from wastewater. The untreated wastewater contained high concentrations of As, Cd, Cr, Co, Cu, Mn, Ni, Pb, Zn, Al, Ca, Fe, Mg, Na, low concentrations of Ba, Be, Ca, Fe, Hg, Li, Rb, Se, Sr, Sn, Ti, V and high levels of organic pollutants. The results showed that the Lemna minor genotype has a high potential to reduce the totally oxidizable organic pollutants from the wastewater with 65%. Lemna minor achieved high removal efficiency of Mn and Pb from wastewater. Also, the results demonstrate the impressive ability of the Lemna minor genotype to accumulate high concentrations of Na, Al, Hg and Fe compared to that of the control plants. Simultaneously, an antagonistic effect was observed in case of the Cu, Ni and Zn after the accumulation metals from the wastewater

Extraction of chlorophyll A, B and carotenoids from nannochloropsis oculata after heavy metal adsorption

The main objective of the present study was to determine the most suitable solvent for photosynthetic pigments extraction from the Nannochloropsis oculata biomass after adsorption of Cu, Zn and Cd from mono and multicomponent solutions. The results revealed that the highest percentage removal of heavy metals from mono solutions was achieved for Zn 20 mg/L (96.2 %), followed by Cu 20 mg/L (92.6 %) and Zn 50 mg/L (92.1 %), respectively. Organic solvents, namely ethanol, methanol and acetone were tested for chlorophyll a, b and carotenoids extractions. It was observed that higher contents of chlorophyll a were obtained after extraction with methanol from algal biomass after Cd and Zn adsorption from single component solutions. After a comparative examination, the highest content of chlorophyll b was obtained after the extraction with acetone

Hydrometallurgical Recovery of Gold from Mining Wastes

Gold is a highly required material for a wide range of personal and industrial applications. The high demand for gold, together with the shortage of natural resources and high pollution potential of wastes generated during mining and ore processing activities led to search for alternative sources of gold. A possible source is represented by mine wastes resulting from the processing of polymetallic or sulfidic ores. The reprocessing of wastes and old tailings with moderate to low content of gold offers not only a business opportunity, but also enhances the quality of the surrounding environment, changes the land use and offers a wide range of socio-economic benefits. Cyanidation, the most widespread Au leaching option, is progressively abandoned due to the high risk associated with its use and to the low public acceptance. Therefore, alternative methods such as thiocyanate, thiourea, thiosulphate and halide leaching gained more and more interest. This chapter presents the most important features of some Au leaching methods, emphasizing their advantages, limitations and potential applications

Correlation Between Human Development and Sustainable Development – Condition of Human Security

For the sake of contemporaneity, the notion of sustainable development has become the key concept in developing new paradigms of human survival, in designing new ways of managing social systems. The current state of today’s humanity is looking for a new development model as well as new security objectives

Removal of Cesium and Strontium Ions from Aqueous Solutions by Thermally Treated Natural Zeolite

The radionuclides of cesium (Cs) and strontium (Sr) are dangerous products of nuclear fission that can be accidentally released into wastewater. In the present work, the capacity of thermally treated natural zeolite (NZ) from Macicasu (Romania) to remove Cs+ and Sr2+ ions from aqueous solutions in batch mode was investigated by contacting different zeolite quantities (0.5, 1, and 2 g) of 0.5–1.25 mm (NZ1) and 0.1–0.5 mm (NZ2) particle size fractions with 50 mL working solutions of Cs+ and Sr2+ (10, 50, and 100 mg L−1 initial concentrations) for 180 min. The concentration of Cs in the aqueous solutions was determined by inductively coupled plasma mass spectrometry (ICP-MS), whereas the Sr concentration was determined by inductively coupled plasma optical emission spectrometry (ICP-OES). The removal efficiency of Cs+ varied between 62.8 and 99.3%, whereas Sr2+ ranged between 51.3 and 94.5%, depending on the initial concentrations, the contact time, the amount, and particle size of the adsorbent material. The sorption of Cs+ and Sr2+ was analyzed using the nonlinear form of Langmuir and Freundlich isotherm models and pseudo-first-order (PFO) and pseudo-second-order (PSO) kinetic models. The results indicated that the sorption kinetics of Cs+ and Sr2+ on thermally treated natural zeolite was described by the PSO kinetic model. Chemisorption dominates the retention of both Cs+ and Sr2+ by strong coordinate bonds with an aluminosilicate zeolite skeleton

Quantitative microbial risk assessment as a tool for groundwater monitoring. A case study in the rural communities of Romania

Karst springs are an essential source of drinking water in rural communities in North-Western Romania. Due to the fractured dolomite aquifers, dolines, or blind valleys, these springs are vulnerable to contamination by human and zoonotic pathogens. In this study, we assessed the human health risk associated with the contamination of six springs’ water with gastrointestinal pathogens. The data on the occurrence of E. coli and estimated Campylobacter and Rotavirus for a year of monitoring from twenty-four samples were inputted into a Quantitative Microbial Risk Assessment (QMRA) model (Machdar et al. 2013). The QMRA was conducted following steps: hazard identification, dose-response assessment, exposure assessment, and risk characterization (Haas C N et al. 2014; World Health Organization 2016). In order to predict the total cases of illnesses for the spring water consumers, the probability of infection and illness was calculated for adults and children. Results have shown that the estimated probability of infection for enteropathogenic E. coli, Campylobacter, and Rotavirus ranged between 1.1 × 10-3 and 1.0 × 100, values much higher than the acceptable limit of 10-4 infections/person/year established by WHO (2016). The estimated probability of illness due to the pathogenic E. coli and Campylobacter infection was high, with values between 8.8 × 10-2 and 3.5 × 10-1 for five out of six groundwater sources. The estimated probability of illness due to the Rotavirus infection ranged between 4.0 × 10-4 and 6.4 × 10-2 for both adults and children. The finding suggests that consuming contaminated spring water could lead to severe acute, chronic, or sometimes fatal health consequences for the locals. This study provides valuable QMRA information on the contaminated karst groundwater, with important implications for human health and groundwater resources management

Contributions on the Determination of the Relationship among Globalization, Sustainable Development and Energy Security

The integrated approach to current security issues requires the study of human society by adopting the principle of sustainability for policies to be developed and applied according to economic, social and environmental impacts. The internationalization of economies raises a number of requirements for the application of this principle not only in domestic policies but also in external cooperation relations. Sustainability is thus a catalyst for internal and external political decisions, economic actions and public opinion to promote both new structural, institutional reforms and changes in production and consumption behaviours. The energy resources have permanently and overwhelmingly influenced the evolution of human society and its economic development, representing both a reason for cooperation and confrontation and disputes among the actors of the international system, while also shaping the economy, security, foreign policy and states priorities