Search

The geochemical analysis of Gafsa rock phosphate (GRP) revealed relatively high concentrations of essential plant minerals and trace heavy metals (HMs). Environmental contamination factors indicated moderate to very strong HM contamination due to GRP soil amendment. The potential use of the Serratia plymuthica BMA1 strain, which is known for its ability to solubilize GRP, to enhance mineral nutrition in Vicia faba L. and its role in HM rhizoaccumulation from GRP were explored. Pot experiments revealed that bacterization with S. plymuthica BMA1 in V. faba grown in sand supplemented with GRP as the sole source of phosphorus significantly increased the potassium concentration by 64% in roots and 40% in shoots, iron by 20% in roots and 10% in shoots, and manganese by 27% in roots and 20% in shoots compared to that in V. faba not inoculated with S. plymuthica BMA1. The total dry biomass of V. faba increased by approximately 85%, while the accumulation of cadmium (Cd), copper (Cu), zinc (Zn), and lead (Pb) in the roots increased by 114%, 30%, 37%, and 44%, respectively. However, in the shoots, they increased by 35%, 10%, 85%, and 25%, respectively, for Cd, Cu, Zn, and Pb compared to those in the non-inoculated V. faba. The evaluation of the HM translocation factor, bioaccumulation factor, and bioconcentration factor with GRP highlighted the key role of S. plymuthica BMA1 in preventing the mobility of toxic HMs from reaching the aerial parts of plants. These findings suggest that S. plymuthica BMA1 has the potential to enhance mineral nutrition in V. faba and facilitate the rhizoaccumulation of toxic HMs, which has implications for plant cultivation and human consumption. [ABSTRACT FROM AUTHOR]

Lake ecosystems in northern Pakistan are the most critical resources that maintain and regulate water flow for downstream agricultural, domestic, industrial, and ecological processes. One consequence of these processes is that ecosystems deposit heavy metals (HMs), where lake stagnant conditions result in high vulnerability of water resources. For this purpose, the present study examined HMs such as cadmium (Cd), chromium (Cr), cobalt (Co), iron (Fe), manganese (Mn), nickel (Ni), lead (Pb), and zinc (Zn) concentrations in high-altitude lakes (HAL) sediments of Mansehra district, northern Pakistan. Sediment samples were collected from the five HAL. This study used HM concentrations in lake sediments for the pollution factors such as contamination factor (Cf), pollution load index (PLI), sediment pollution index (SPI), ecological risk assessment (ERA), and risk index (RI). Among HMs, Fe showed the uppermost levels of 1410 mg/kg in lake sediment, while Cd with lowermost levels of 1.05 mg/kg. Results revealed that most HM concentrations in HAL sediments were within the threshold of sediments quality guidelines (SQGs), except for Cd. Among lakes, the sediments of Siri Lake showed higher contamination of HMs than others. Siri Lake sediments also showed higher Cf, PLI, ERA, and RI values than others. The majority of HMs in HAL sediments showed no contamination, except for Cd (considerable) and Pb (moderate) levels to the exposed aquatic ecosystem. This study revealed that 95% of sediment samples in HAL were noted low to medium-level risks to the exposed aquatic communities. Statistical and geospatial analyses revealed that geogenic sources of contamination are a significant contributor to HM contamination of HAL sediments compared to others. [ABSTRACT FROM AUTHOR]

Copyright of Petroleum Refinery Engineering is the property of Petroleum Refinery Engineering Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Sediments were considered a sink and potential source of heavy metals in the aquatic system. For this purpose, the present study examined surface sediments for spatial and temporal variation of heavy metals pollution and risk indices in the Gomal Zam Dam Basin (GZDB), Pakistan. Sediment samples (n = 20) were collected from the GZDB, i.e., Gomal Zam Dam, its inlets, and outlets in the winter and summer seasons of 2020, and examined for heavy metals such as zinc (Zn), nickel (Ni), manganese (Mn), lead (Pb), chromium (Cr), copper (Cu), iron (Fe), and cobalt (Co) concentrations. Among GZDB, results showed that the Zhob River Inlet had a higher levels of heavy metals in both seasons. The results revealed that pollution load index values were < 1, observing no pollution in the aquatic system. The risk indices values revealed that sampling sites showed no or very low risk during the summer, 84% of samples showed no or very low risk during the winter, and the rest noted with reasonable risks. Winter season showed higher average values of contamination and risk indices than summer. Statistical analyses revealed that the heavy metals contaminations were mainly due to geogenic sources of rock weathering and ore deposits, with minor contributions from anthropic activities. This study recommends regular monitoring of temporal studies on heavy metals contamination in the water of the GZDB. [ABSTRACT FROM AUTHOR]

This study aimed to compare global solar radiation on the horizontal area between two models of Chabane Foued and M.Capderou. The model of Chabane has been interested in pollution factors such as TL (turbidity), BE (Angstraon), and the chemical components of the air such as WV, O3, CH4, CO, CO2, and the especial part the new pollution factor such as hbeam, kbeam, and kdiffuse, which all influenced onto solar radiation, and the model of Capderou has been used the atmospheric disturbance to calculate the direct and diffuse components of radiation received on a plane, while the constituents of the atmosphere (absorption and diffusion) can be expressed by disturbance factors, which is very necessary to determine irradiation In the clear sky. The results reveal a significant difference between the two models with approximated curves. The difference between the models probably returns to the nature of the geographic site which the authors used and injected into the models.

Link for citation: Maksimova A.A., Chernykh A.V., Novikov D.A., Dultsev F.F., Derkachev A.S., Sukhorukova A.F., Nikitenkov A.N., Khvachshevskaya A.A. Toxic elements in groundwater in the northern regions of the Ob-Zaysan folded region. Bulletin of the Tomsk Polytechnic University. Geo Аssets Engineering, 2023, vol. 334, no. 5, рр.17-26. In Rus. The relevance of this research lies in the need to study the distribution of elements of the first hazard class, uranium and thorium in the groundwater of the Ob-Zaisan folded area. Objective: to establish the characteristics of the hydrogeochemical background and to study the distribution of highly toxic chemical elements in the waters of the drinking water supply of the population. Methods. Rapidly changing parameters were determined using a field hydrogeochemical laboratory and field equipment Hanna HI98195 – a multi-parameter pH/ORP/conductivity meter, Hanna HI98198 – an oximeter. The measurement of radon activity in groundwater was carried out using the Alfarad plus complex. Laboratory studies of the chemical composition by means of titration, ion chromatography, mass spectrometry with inductively coupled plasma were carried out at the Research Laboratory of Hydrogeochemistry at the School of Earth Sciences and Engineering of the Tomsk Polytechnic University. The assessment of the toxicological characteristics of waters was carried out using the current regulatory documents: SanPiN 2.1.3684-21, SS R 58573-2019 and the recommendations of the World Health Organization. The hydrogeochemical background was calculated using the Statistica 8.0 software package (StatSoft. Inc.). To determine the extent of element concentrating in natural waters, the coefficients of concentration and water migration (according to A.I. Perelman) were calculated. Cumulative curves are calculated by the formula: Pc=Ri/(N+1). Results. The studied waters are HCO3 Mg-Ca and HCO3 Na-Mg-Ca composition with total mineralization varying from 203 to 1568 mg/dm3. The geochemical parameters of the environment are both reducing and oxidizing with Eh –331,6 – +438,5 mV, pH 6,6–8,3 with the content of O2disol. 0,29–10,72 mg/dm3. The authors revealed relatively high concentrations of Ti – up to 0,04 mg/dm3, V – up to 0,03 mg/dm3, Fe – up to 93,9 mg/dm3, Zn – up to 0,38 mg/dm3, As – up to 0,27 mg/dm3, Zr – up to 0,018 mg/dm3, Sb – up to 0,016 mg/dm3, Ba – up to 0,51 mg/dm3, W – up to 0,005 mg/dm3, Hg – up to 0,0002 mg/dm3, Pb – up to 0,057 mg/dm3, U – up to 0,34 mg/dm3, which is probably related to the composition of host rocks and the spread of industrial enterprises developed in the study area. The elements of the first hazard class, as well as uranium and thorium, were studied in the work. It was found that 20 % of the studied samples were higher than the background value for beryllium, as well as for thallium and arsenic, 26 % – for thorium, and 19 % – for uranium.

Background: Drill cutting is one of the largest volumes of waste generated in oil and gas exploration and production activities, which contain toxic substances, especially heavy metals, which are potentially harmful to the ecosystem. This study aimed to investigate the pollution indices, available ratio, and ecological risk of some heavy metals in the Drill cutting of the Ahvaz oil field in southwestern Iran. Methods: 30 samples of drill cutting were collected from 6 wells in 6 different depths (1250-2350 m), and there were sent to the laboratory. The total and available concentration of metals extracted by Aqua Regia method and by DTPA extracting solution and metals were analyzed by Inductively Coupled Plasma Optical Emission Spectroscopy (ICP-OES) and Atomic Absorption Spectrophotometry(AAS). The soil chemical and physical parameters such as organic matter, EC, and pH were also measured. Results: The mean total concentration (Sr, Ba, Zn, Cu, Pb, Cd) in the drill cutting samples studied 1212, 1413, 117.66, 209.83, 342.66, 2.36 mg/Kg, respectively and the available amounts of these elements 12.29, 0.50, 5.14, 14.71, 23.80 and 0.46 mg/kg were measured. The highest amount of enrichment factor 20.61 was related to Pb and the highest amount of pollution index 9.15 was related to Cd, respectively. The highest available ratio (26.40) was related to Cd. The environmental risk potential index (852.91) showed that drill cuttings have very high environmental potential risk. Also, there is a negative correlation between pH and the availability ratios of Pb, Cd, and Ba in drill cutting(p

In this study, the geographic distribution of toxic element concentrations was determined in Northeast Marmara Sea (Istanbul/Turkey) sediments. In addition, the pollution degree of the environment was analyzed using various pollution index methods. Geochemical analysis of 28 elements were performed in sediment samples. The concentrations of several elements (especially Fe, Mn, Ti, Zn, and Cr) were found to be very high in some locations. At sites, where heavy metal concentrations were high, foraminifera genera and species numbers and number of individuals were very low. The low number of foraminifera in the samples taken from some regions could be due to uncontrolled ship traffic and domestic and industrial discharges. [ABSTRACT FROM AUTHOR]

It has great a subjective influence on the evaluation of major heavy metal pollution factors in coastal waters and sediments by using the traditional Nemerow exponential method, without considering the harmful differences of different heavy metals, and resulting in a low accuracy of the evaluation results. In this paper, a new model to evaluate the major heavy metal pollution factors in coastal waters and sediments is established, to calculate the single pollution index and potential ecological risk index of heavy metals. On this basis, the fuzzy comprehensive evaluation method is used to construct the main heavy metal pollution factor model of coastal waters and sediments. The heavy metal pollution factor is reasonably evaluated and the risk grade of heavy metal pollution factor in coastal waters and sediments is obtained. The results of sampling analysis show that the evaluation results obtained by the model are as follows: the pollution index of heavy metals in the coastal water with the order of Pb > Cu > Hg > As > Cd > Zn; the potential ecological risk index of heavy metals in sediments is Pb > Cu > As > Zn > Hg > Cd. The pollution degree of area C is the highest, area A is the second, and area B is the smallest. The results show that the model can accurately evaluate the main heavy metal pollution factors in coastal waters and sediments. [ABSTRACT FROM AUTHOR]

Along with the increasing complexity of electric power systems, there is an increment on the quality standards of the electric energy supplied. The power quality refers also to the continuity of the service, which is greatly affected by failures that produce outages of transmission and distribution lines. Failures in distribution networks significantly affect the cost and quality of power supplied [1], and there is a continuous search for actions to reduce the possibility of failures. [ABSTRACT FROM PUBLISHER]

Based on the analysis on the infection degree, infection law and influencing factors of the main diseases on asparagus and the analysis on the pollution factors in asparagus production such as blind pesticide use, atmospheric pollution and acid rain, the pollution of soil and fertilizer, this article proposes asparagus safety production technologies which include the selection of disease-resistant variety and suitable planting field, scientific and reasonable disease control, balanced fertilization, rational irrigation, making a good job of field management, etc., to reduce pathogenic factors. [ABSTRACT FROM AUTHOR]

The paper attempts to present some aspects concerning the natural frame of the mentioned littoral zone and some recommendations for a durable and quality development especially for pleasure and balneary tourism field. After a short description of the natural frame of the mentioned littoral zone are presented the known pollution factors especially in the north part of the investigated zone and the negative anthropic actions which affected for a long time the terrestrial and waters environment, next to the coast. The numerous constructions transformed Mamaia in a small town with negative impact on the green spaces, considerably reduced in the last years. Important is another negative impact factor, the land clearing of the Eleagnus angustifolia L. skirt from the sand beaches upper-water mark. At last are presented some concrete measures which may be taken to extend the green spaces to limit the pollutants emission in the north part of the investigated zone. [ABSTRACT FROM AUTHOR]

In this paper, the pollution factors of groundwater environment are analyzed via grey relational analysis (GRA). In grey relational analysis, the total hardness is taken as reference factor; four factors: precipitation, evaporation, groundwater depth and CI- are compared factors. GRA shows that precipitation ranks the major one. CI- the next, evaporation rank the end. [ABSTRACT FROM AUTHOR]