Artificial neural network applied in forecasting the composition of municipal solid waste in Iasi, Romania

Neural network time series (NNTS) tool was used to predict municipal solid waste composition in Iasi, Romania. The nonlinear input output (NIO) time series model and nonlinear autoregressive model with external (exogenous) input (NARX) included in this tool were selected. The coefficient of determination (R2) and root mean square error (RMSE) were chosen for evaluation. By applying NIO, the optimum model is 4-11-6 artificial neural network (ANN, R2 = 0.929) in the case of testing as for the validation, with all 0.849 and 0.885, respectively. Applying NARX, the suitable model became 4-13-6 ANN model, with R2 = 0.999 for training, 0.879 for testing, and 0.931, respectively 0.944 for validation and all. The resulted RMSE is zero for training and 0.0109 for validation in the case of this model which had 4 inputs, 13 neurons and 6 outputs. The four input variables were: number of residents, population aged 15–59 years, urban life expectancy, total municipal solid waste (ton/year). The suitable ANN model revealed the lowest root mean square error and the highest coefficient of determination. Results indicate that NNTS tool is a complex instrument, NARX is more accurate than NIO model, and can be used and applied easily

Modelling of Health Risk Associated with the Intake of Pesticides from Romanian Fruits and Vegetables

This study is focused on the assessment of risks caused by pesticide residues to Romanian and other European populations, by modelling the acute and chronic risks considering short- and long-term exposures to pesticide residues in specific fruits and vegetables from different Romanian regions. Data were obtained from the Romanian 2016 official monitoring programme. For assessing the dietary risk, we used the Pesticide Residue Intake model—PRIMo. According to the official data, it was found that 50.44% of fruit samples and 28.25% of vegetable samples were contaminated with pesticides. Our study focused on acute risks and chronic risks (in a maximalist worst-case scenario) posed by pesticide residues in strawberries, apples, lettuce and potatoes, given both their high degree of consumption and contamination with pesticides. The short-term exposure assessment of children’s health due to consumption of apples, lettuce and potatoes contaminated with dimethoate, chlorothalonil and carbendazim, revealed exposure levels higher than the acute reference dose (ARfD, as 100%), raising acute risks. On the other hand, the long-term exposure assessment showed that the highest percentage from the acceptable daily intake (ADI, as 100%) was obtained for German children (DE child) (273.9%), followed by Netherlands children (NL child) (143.7%) diets, based on consumption of apples with dimethoate residues. Therefore, serious measures are needed for banning pesticides such as dimethoate, chlorothalonil and carbendazim from all countries in the EU. This would reduce the health risks generated by the consumption of contaminated fruits and vegetables

Comportamentul unor pesticide aplicate în tratamente multiple în mere

The main objective of this work addresses kinetic studies on the dissipation of 12 pesticides applied in single recommended doseand double dose treatments in apples, considering 6kinetic models which determine the statistical parameters describingpesticide behavior, including their half-lives. The half-lives of pesticides in apples at BBCH (Biologische Bundesanstalt, Bundessortenamt and CHemical industry) scale 76-79 resultedfrom the linear regression equations considering single dose treatments were between 0.01 days (for λ-cyhalothrin) and 74.90 days (for myclobutanil).Data on the rate of dissipation and half-lives of pesticides in various plant compartments are particularly significant for pesticide monitoring and human health impacts and risk assessment

Comparison of Rhodotorula sp. and Bacillus megaterium in the removal of cadmium ions from liquid effluents

This study compares the capacity of Rhodotorula sp. and Bacillus megaterium for Cd(II) removal considering the influence of operating parameters (pH, biosorbent dosage, contact time, temperature, initial metal concentration in solution). The highest Cd(II) uptake of 14.2 mg/g by Rhodotorula sp. was exhibited at 30°C, when working at pH 6 and with 5 g/l biosorbent dosage, after 48 h of contact time. In these conditions, a removal efficiency of 85% was obtained. Similar outcomes were obtained for B. megaterium (15.1 mg/g, 90%) at 35°C, pH 4 and 3 g/l biosorbent dosage, considered as the optimum set of parameters, equilibrium being achieved for a contact time of 20 min. The possible interaction mechanisms between the biosorbents and Cd(II) were evaluated through point of zero charge (pHpzc), Fourier transform infrared (FTIR), spectroscopy and scanning electron microscopy coupled with energy dispersive X-ray microanalysis (SEM-EDX). Data were modeled using pseudo-first and pseudo-second order kinetic models and Langmuir and Freundlich isotherms models. Further studies considered a modeling approach based on linear regression with Durbin-Watson statistics, while the accuracy and precision of experiments were evaluated by ANOVA.This work was supported by two grants of the Romanian National Authority for Scientific Research, CNCS–UEFISCDI: PN-II-ID-PCE-2011-3-0559, Contract 265/2011 and project number PN-III-P2-2.1-PED-2016-1662, Contract 10/2017 within PNCDI III. The Portuguese team input was performed under the scope of the strategic funding of UID/BIO/04469/2013 unit and COMPETE 2020 (POCI-01-0145-FEDER-006684) and BioTecNorte operation (NORTE-01-0145-FEDER-000004) funded by the European Regional Development Fund under the scope of Norte2020 Programa Operacional Regional do Norte.info:eu-repo/semantics/publishedVersio

Thermodynamic study of Cd (II) sorption on soil

Sorption is a major process responsible for the fate of heavy metals in soils, since the mobility of heavy metals is directly related to their partitioning between the soil solid phase and soil solution. Among the heavy metals cadmium is one of the most toxic with adverse health effects. The objective of this study is to analyze the sorption of Cd(II) from aqueous solution on soil from the industrial area of the city of Iasi (Romania) as a function of temperature at natural pH of the solution using a batch technique. A maximum uptake of about 9.7 mg of cadmium per g of soil and aprox. 95 % removal of metal was observed at 20 g/L soil amount, 200 mg/L cadmium solution and 41 °C, with an equilibrium time of 24 hours. Sorption isotherm of Cd(II) on soil were represented by Freundlich and Dubinin-Radushkevich models and the parameters indicated that the sorption of Cd(II) increased with increasing temperature of the system. Enthalpy (ΔH0 ), entropy (ΔS0 ) and Gibbs free energy (ΔG0 ) were calculated from the temperature dependent sorption data, and the results indicated that the sorption of Cd(II) on soil is a spontaneous, feasible and endothermic process

New evidence of model crop Brassica napus L. in soil clean-up: comparison of tolerance and accumulation of lead and cadmium

The potential of the model crop Brassica napus L. (rapeseed) for the phytoremediation of soils polluted with metals was investigated at laboratory scale. The first step consists in the evaluation of the seed germination and growth of the Brassica napus L. plant in a controlled environment, followed by the determination of the photosynthetic pigments content represented by chlorophyll a and b and carotenoids. The degree of metal accumulation in rapeseed has been evaluated by the bioaccumulation factor (BAC), the bioconcentration factor (BCF) and the translocation factor (TF). Phytotoxicity tests were performed in Petri dishes with filter papers moistened with metal solutions in the range of 0 to 300 mg/L Pb(II) or Cd(II). At the highest concentration of the lead and cadmium treatments (300 mg/L), B. napus L. showed the lowest germination degree (56.67% and 43.33%, respectively). According to Tukey test results, Pb(II) concentrations of up to 300 mg/L do not significantly affect the length of the hypocotyls, whereas, in the case of Cd(II), the mean of the radicle and hypocotyl lengths of the seedlings are significantly affected compared to the mean of the control. In soil pot experiments, important changes have been obtained in the pigment content, especially in the case of cadmium. For both metals and for each treatment (100 to 1500 mg/kg Pb(II) and 1 to 30 mg/kg Cd(II)), a TF < 1 indicates an ineffective metal transfer from root to shoot. Finally, rapeseed can be considered a tolerant plant and a suitable candidate for Pb(II) and Cd(II) accumulation and for the phytostabilization of contaminated soil under the experimental conditions adopted in the present study

Potenţialul unor microorganisme şi plante indigene de eliminare a metalelor grele din sol

Heavy metals found in soils from different industrial sources or mining activities are persistent inorganic pollutants able to bioaccumulate along the food chain and cause negative effects in theenvironment and for human health. Differentphysical, chemical and biological processes are applied for their removal from soil environments. Biological processes become more and more preferred, since bioremediation strategies have often proved to be more advantageous than the conventional remediation tools, mainly because these processes can be implemented directly onto the contaminated sites (in situ). In this context, the present paper examines the abilityof microorganisms and plants to remove heavy metals from soil, in terms of tolerance and bioaccumulation. A particular interest is given to the bioaccumulation processes of metals by proteobacteria, bacilli and actinobacteria, alone or in synergismwith indigenous plants. Also, some advances in the biosorption of highly toxic heavy metal ions as Cr(VI) and Cd(II) are just discussed,together with various strategies and practices to explore the synergism between microorganisms and plants as valuable biological resource for increasing tolerance against heavy metals and strengthening the bioremediation processes

Screening of <i>Azotobacter</i>, <i>Bacillus</i> and <i>Pseudomonas</i> Species as Plant Growth-Promoting Bacteria

In this study, bacteria from the genus of Azotobacter, Bacillus and Pseudomonas were isolated from the roots of Phaseolus vulgaris and used as plant growth-promoting bacteria for Sinapis alba L., Brassica napus L., Amaranthus retroflexus L., Linum usitatissimum L., Panicum miliaceum L. and Rumex patientia L. plants. The results showed that all three bacteria had different effects on plants growth considering both sterile and non-sterile soil. Bacillus sp. induced the greatest influence in terms of the root length of Sinapis alba L. grown in sterile soil (with 28%), while considering non-sterile soil, Pseudomonas sp. increased the root and shoot length by 11.43% and 25.15%, respectively, compared to the blank sample. Azotobacter sp. exerted the highest beneficial influence on Brassica napus L. growth in non-sterile soil, since the root and shoot lengths were stimulated with 27.64% and 52.60%, respectively, compared to uninoculated plants. Bacillus sp. had a positive effect on the growth of the shoot length of Amaranthus retroflexus L. (with 30.30% in sterile soil and 3.69% in non-sterile soil compared to the control). Azotobacter sp. stimulated the growth of the root length of Rumex patientia L. with 35.29% in sterile soil and also the shoot length of Panicum miliaceum L. in non-sterile soil by 20.51% compared to the control. Further, the roots and shoots of Linum usitatissimum L. grown in non-sterile soil and in the presence of Pseudomonas sp. increased by 178.38% and 15.08%, respectively, compared to the flax grown in sterile soil. Statistically, according to Tukey’s Honestly Significant Difference (HSD) test results, not all observed differences in plants grown with the selected bacteria are significantly different compared to the control

Sorption of Organic Pollutants onto Soils: Surface Diffusion Mechanism of Congo Red Azo Dye

For the protection of human and ecological receptors from the effects of soil pollution with chemical compounds, we need to know the behavior and transport of pollutants in soil. This work investigated the Congo red (CR) acid dye sorption on three natural soils collected from central and northeastern regions of Romania, symbolized as IS-65, IS-T, and MH-13. To define the mechanism of sorption and identify the rate governing step, various diffusion models such as Weber&ndash;Morris intraparticle diffusion, Boyd, film and pores diffusion, and mass transfer analysis have been verified. The intraparticle diffusion analysis of Congo red sorption onto soils has been described by a multi-linear plots, showing that the sorption process takes place by surface sorption and intraparticle diffusion in macro, meso, and micropores. The values of intraparticle diffusion coefficient kid increased with any rise of the initial concentration of pollutant. The results show that the values of pore diffusion coefficient (Dp) and film diffusion coefficient (Df) are found to be from 10&minus;8 to 10&minus;10 cm2 s&minus;1, indicating that film diffusion influences the sorption rate limiting step. The intraparticle diffusion analysis shows that the plots did not pass through the origin and have two distinct parts, confirming that intraparticle diffusion is not the single determining mechanism involved in the sorption of Congo red on soils IS-65, IS-T, and MH-13. The results revealed that the sorption process has a complex nature, since both external diffusion and internal diffusion are involved in the sorption of CR from solution onto the investigated soils