scholarly journals Release Behaviors of Arsenic and Heavy Metals from Arsenic Sulfide Sludge during Simulated Storage

Minerals ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 130 ◽  
Author(s):  
Liwei Yao ◽  
Xiaobo Min ◽  
Yong Ke ◽  
Yunyan Wang ◽  
Yanjie Liang ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Preventive Measures ◽  
Oxidation Process ◽  
Ferrous Metal ◽  
Environmental Risks ◽  
Arsenic Sulfide ◽  
Drying Process ◽  
Secondary Pollution ◽  
Release Ratio ◽  
Natural Drying

Non-ferrous metal smelting enterprises produce hundreds of thousands of tons of arsenic sulfide sludge (ASS) each year in China. Most of the ASS are stored at the companies without enough preventive measures. During the storage and natural drying process, arsenic sulfide is easily oxidized, thereby causing secondary pollution and increasing environmental risks. In this paper, experiments of simulated storage were used to study the release characteristics of heavy metals. During the simulated storage, the release concentrations of As, Pb, and Cd increased rapidly at first and then slowly. Although the total amount of arsenic released was the largest, the release ratio was in the order of Cd > Pb > As. The effects of different atmospheres and conditions on the release of arsenic and heavy metals were explored. The more the H2SO4 in the sludge, the higher the release concentration, and the addition of an appropriate amount of Ca(OH)2 is beneficial for reducing the release of heavy metals. Finally, SEM, XRD and TG-DTG techniques were carried out to confirm that the release of heavy metals was caused by the oxidation process resulting from the residual H2SO4 in the ASS and the air.

The Concentration and the Abatement Strategy of Organic Contaminants in Sewage Sludge Dewatering

2011 ◽  
Vol 356-360 ◽  
pp. 1495-1499
Author(s):  
Jie Yu ◽  
Guo Di Zheng ◽  
Tong Bin Chen
Keyword(s):  
Sewage Sludge ◽  
Organic Contaminants ◽  
Environmental Risks ◽  
Future Research ◽  
Sludge Dewatering ◽  
Sludge Disposal ◽  
Secondary Pollution ◽  
Pollution Problem ◽  
Safety And Environment ◽  
Abatement Strategy

Sludge agriculture application in future will be one of the main sewage sludge disposal ways in China. To ensure safety and environment of sewage sludge agriculture application, except to strengthen the research of sludge heavy metal, pathogen outside the organic contaminants will be one of the focuses of the future research, especially to strengthen the PAHs and NP/NPE. In order to reduce the environmental risks of sludge agriculture application, using biological aerobic fermentation processing technology treatment sludge can effectively reduce the organic contaminants, depress secondary pollution problem, which sewage sludge brings.

scholarly journals Prospects for optimizing the drying process of Virginia 202 tobacco leaves

2021 ◽  
Vol 17 (1) ◽  
pp. 70-77
Author(s):  
E. Е. Ulyanchenko ◽  
N. N. Vinevskaya
Keyword(s):  
Quality Indicators ◽  
Raw Materials ◽  
Control Sample ◽  
Physical Method ◽  
Cost Effective ◽  
High Energy ◽  
Drying Process ◽  
Drying Time ◽  
Apply Physical ◽  
Natural Drying

Cultivation and use of Virginia 202 broadleaf skeletal variety for the production of smoking tobacco has broad prospects. Problems of post-harvest processing of large leaves with a massive midrib consist in high energy costs with an artificial drying method or the provision of facilities for long-term natural drying. The aim of the research is to apply physical method of cutting the leaf midrib to intensify drying and to determine the effect of this technique on the quality indicators of raw materials. It has been found that the technique of cutting the midrib on the Virginia 202 variety contributes to a significant optimization of the drying process without reducing the quality of raw materials. The drying time of leaves with the combined method is reduced by 2,8 times, with the natural method – by 2,3 times, and the quality indicators of raw materials improve. Commercial quality is characterized by the yield of 1 commercial grade, for combined drying the yield of 1 grade has increased in comparison with the control sample by 27% and amounted to 86,5%, with natural drying – the increase in yield is 4%. Cutting the midrib increases the fiber yield by 3–5% and contributes to an increase in the volumetric-elastic properties of the fiber, providing an economical consumption of raw materials for the production of smoking articles, the consumption is 676,8–753,8 g/1000 pcs. The gustatory quality improves, raw materials with a cut midrib have optimal values of the ratio of carbohydrate-protein balance in the range of 1,08–1,5, the strength is preserved due to the lower consumption of nicotine during the shorter drying period, in comparison with drying the leaf without cutting the midrib. Cutting the midrib in Virginia 202 is cost effective.

scholarly journals Incidence of Lead, Cadmium, Chromium, Nickel and Cobalt in Basil, Rosemary and Peppermint Seasonings from Romanian Market

2021 ◽  
Vol 78 (1) ◽  
pp. 19
Author(s):  
Denisa CIOTEA ◽  
Elena UNGUREANU ◽  
Gabriel MUSTATEA ◽  
Mona Elena POPA
Keyword(s):  
Heavy Metals ◽  
Bioactive Compounds ◽  
Food Industry ◽  
Aromatic Plants ◽  
Drying Process

The use of seasonings is important in food industry because the bioactive compounds contained in these dried aromatic plants improve the taste and the flavor of food. These dried aromatic plants can often be contaminated with some heavy metals, polycyclic carbohydrates residues and pesticides which may occur during the cultivation operation, drying process, manufacture and conditioning. The aim of this study is to determine the contamination with heavy metals (lead, cadmium, chromium, nickel and cobalt) of basil (B), rosemary (R) and peppermint (M) seasonings used in Romanian cuisine. The concentration of lead ranged 0.058 - 0.643 mg.kg-1 (M), 0.209 - 0.493 mg.kg-1 (R), 0.077 - 0.139 mg.kg-1 (B). The concentration of cadmium varied: 0.004 - 0.035 mg.kg-1 (M), 0.004 - 0.007 mg.kg-1 (R), 0.002 - 0.009 mg.kg-1 (B). The concentration of chromium ranged 0.304 - 0.403 mg.kg-1 (M), 0.450 - 0.457 mg.kg-1 (R), 0.208 - 0.336 mg.kg-1 (B). The concentration of nickel varied from 0.376 - 0.848 mg.kg-1 (M), 0.354 - 0.427 mg.kg-1 (R), 0.230 - 0.334 mg.kg-1 (B). The concentration of cobalt ranged 0.037 - 0.167 mg.kg-1 (M), 0.065 - 0.137 mg.kg-1 (R), 0.112 - 0.156 mg.kg-1 (B).

Field monitoring of ripening of dredged material at three sites in the Netherlands (preliminary results)

1998 ◽  
Vol 37 (6-7) ◽  
pp. 371-378 ◽  
Author(s):  
W. de Haan ◽  
K. J. Otten ◽  
J. J. M. Heynen ◽  
H. Folkerts ◽  
M. Elsman
Keyword(s):  
Mineral Oil ◽  
Monitoring Programme ◽  
Dredged Material ◽  
Drying Process ◽  
Ripening Process ◽  
Calibration And Validation ◽  
Input And Output ◽  
Clayey Material ◽  
Leaching Characteristics ◽  
Natural Drying

Ripening of dredged material in a deposit is a natural ‘drying’ process by which raw dredged material transforms into soil. The aim of ripening is to obtain soil which complies with environmental legislations and geotechnical specifications for application in earthworks (e.g. dikes, noise reduction banks, landfill covers). The paper deals with the background and contents of a monitoring programme on the ripening behaviour of clayey, peaty, and sandy dredged material, and changes in chemical composition, especially of organic compouds, and leaching characteristics during ripening. The main objectives of the monitoring programme are (1) to develop a management system for the ripening process, (2) to quantify the input and output volumes of dredged material, and (3) to develop guidelines for the design of (transit) deposits. The results of the monitoring programme will also be used for calibration and validation of a computer model on ripening. Prelimanary results on ripening of clayey material and biodegration of PAH and mineral oil are presented. On the basis of these results it is expected that large volumes of slightly to moderately contaminated dredged material are suitable for beneficial use after ripening.

Investigation of the Influence of Aerotechnogenic Pollution on the Accumulation of Heavy Metals in the Plant-Soil System

2019 ◽  
Vol 23 (6) ◽  
pp. 52-57
Author(s):  
M.V. Medvedeva ◽  
T.S. Titova ◽  
O.N. Bakhmet ◽  
A.N. Pekkoev ◽  
V.A. Kharitonov
Keyword(s):  
Heavy Metals ◽  
Woody Plants ◽  
Ash Content ◽  
Environmental Risks ◽  
Soil System ◽  
Plant Soil ◽  
Railway Infrastructure ◽  
Aerotechnogenic Pollution ◽  
Pollution Accumulation ◽  
Environmental Measures

It is shown that the chemical composition of the litter falls and wood of deciduous and coniferous trees is different. On the background of aerotechnogenic pollution, accumulation of individual heavy metals, an increase in ash content was noted. There was revealed the anthropogenic dynamics of the accumulation of heavy metals in the wood of trees: the maximum number during the period of diesel traction; as the railway site is electrified, the accumulation of elements decreases. The obtained data can be recommended to be used for phytoremediation at sites subject to pollution. The obtained data will be the basis for assessing the phytoextractive potential of woody plants, in diagnosing aero-technogenic pollution of the environment, solving the problem of reducing environmental risks, as well as during the modernization and planning of environmental measures in the field of railway infrastructure.

scholarly journals Contamination of bottom sediments by lead, zinc and cadmium in Rzeszow reservoir

2018 ◽  
Vol 29 (4) ◽  
pp. 10-15
Author(s):  
Katarzyna Maj-Zajezierska ◽  
Piotr Koszelnik
Keyword(s):  
Heavy Metals ◽  
Bottom Sediments ◽  
Sediment Quality ◽  
Environmental Risks ◽  
Sediment Classification ◽  
Quality Classification ◽  
Lead Zinc ◽  
Aquatic Sediment ◽  
Positive Effect

Abstract The aim of the present study was to determine the level of contamination of the bottom sediments in the Rzeszow reservoir by the selected heavy metals Pb, Cd and Zn, and to identify the potential environmental risks of heavy metals content basing on available assessments and classification of bottom sediments. The Rzeszow reservoir is situated on the Wisłok River in the Podkarpackie Voivodeship, southeaster Poland, was constructed on 1974. Nowadays, as a result of silting, the reservoir reduced its surface and depth, which does not have a positive effect on the assumed functions it is to perform. The study was conducted in 2016. The samples of sediment were collected in five locations. Samples were taken twice: in June and in October. The following concentrations have been determined: cadmium - 0.01 ÷ 0.92 mg•kg–1, zinc - 54.39 ÷ 128 mg•kg–1, lead - 2.98 ÷ 25.42 mg•kg–1. The decline trend in the sediment is following: Zn > Pb > Cd. For the assessment of sediment contamination, following methods: aquatic sediment quality classification used by the Polish Geological Institute - I class, Regulation of the Minister of Environment of April 16 2002 on the types and concentrations of substances contaminating the excavated material – unpolluted and LAW sediment classification – Pb - I/I-II, Cd - I/I-II/II and Zn - I/I-II. The obtained results were compared with the results obtained by the other authors in earlier years, which led to the estimated changes in the concentration of the tested metals.

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