scholarly journals Treatment of leachates in hightech systems

2019 ◽  
pp. 29-38
Author(s):  
Ulrika Welander

Leachates are complex wastewaters, which often contain high concentrations of ammoniwnions, refractory organic compounds as well as heavy metals. The composition of the leachateis a function of the kind of waste that has been deposited at the landfill. Furthermore,substances created during microbial and abiotic degradation processes of the waste will beeluted from the landfill. It is therefore difficult to determine the chemical composition of aleachate especially in regard to organic substances. Leachates from different landfills differ incomposition. No single treatment process is therefore suitable for all leachates. The processhas to be optimised for the specific leachate, which will be treated.

1970 ◽  
Vol 39 (1) ◽  
pp. 61-69 ◽  
Author(s):  
Ashafaque Ahmed ◽  
Mikael Ohlson ◽  
Sirajul Hoque ◽  
Md Golam Moula

Chemical composition of leaves of Sonneratia apetala Buch.-Ham. collected from three islands (chars) representing three hydrological regimes in a segment of the coastal zone of Bangladesh was studied. Their relations to some soil chemical and physical variables have also been investigated. The results showed that concentrations of B, C, Fe, Ga, Li, Mg, Mn, N, Na, P, Zn and Sr in leaves of S. apetala grown in different islands differed significantly. It was also revealed that some heavy metals, viz. Mn, Fe, Al, Sr and Ti showed wide range of concentrations. The leaves from one of the locations in Motherbunia island were characterized by exceptional high concentrations of heavy metals such as Al, As, Cu, Fe, Li, Ni, Pb that may be due to local contamination. Leaves sampled in the most seaward locations of the same island had highest concentrations of Ba, Ca, Cu, Mn and Na. High Mn concentration was found in the leaves of S. apetala of Motherbunia island. Correlations among soil and plant samples were generally very weak and organic matter content of soil did not appear to play a significant role in the nutrient supply of S. apetala. Key words: Coastal zone; tidal inundation; elemental concentration; Sonneratia apetala DOI: 10.3329/bjb.v39i1.5528Bangladesh J. Bot. 39(1): 61-69, 2010 (June)


Author(s):  
Luiza Fernanda dos Santos Pereira ◽  
Marcos Roberto Furlan ◽  
Paulo Fortes Neto

Disposal of solid waste in landfills causes negative impacts on the environment, caused by emissions of greenhouse gases and the release of dark-colored leachate. It’s composition includes high concentrations of suspended solids, heavy metals, salts and organic compounds. Given the above, this study evaluated the use of superabsorbent polymer in the treatment of leachate. Slurry samples were collected at the Taubaté landfill in two seasons to determine electrical conductivity, pH, turbidity, oils and greases. Other samples were submitted to the following treatments: 3.5 g of polymer with 500 g of distilled water, and doses of 3.5; 7.0; 10.5; 14.0; 17.5; 21.0; 24.5; and 28.0 g of polymer with 500 g of slurry, with 4 repetitions each. Other steps, in sequence, were: transformation of the material into gel (gelation), obtaining the liquid volume of water and slurry, and after 0, 12, 24, 48 and 72 h, measurements of polymer dehydration were obtained. The efficiency of doses was determined by the volume of leachate remaining after each treatment. Gelation was more efficient in the summer season, a season with lower values of electrical conductivity, pH, suspended solids, and oils and greases. The most efficient doses in gelation were 10.5 g in summer and 14.0 g in autumn. In conclusion, superabsorbent polymer can be used in the treatment of leachate because it allows its gelling, but the recommended doses vary with the seasons.


2021 ◽  
Vol 11 (14) ◽  
pp. 6592
Author(s):  
Ana Moldovan ◽  
Maria-Alexandra Hoaghia ◽  
Anamaria Iulia Török ◽  
Marius Roman ◽  
Ionut Cornel Mirea ◽  
...  

This study aims to investigate the quality and vulnerability of surface water (Aries River catchment) in order to identify the impact of past mining activities. For this purpose, the pollution and water quality indices, Piper and Durov plots, as well vulnerability modeling maps were used. The obtained results indicate that the water samples were contaminated with As, Fe, Mn, Pb and have relatively high concentrations of SO42−, HCO3−, TDS, Ca, K, Mg and high values for the electrical conductivity. Possible sources of the high content of chemicals could be the natural processes or the inputs of the mine drainage. Generally, according to the pollution indices, which were correlated to high concentrations of heavy metals, especially with Pb, Fe and Mn, the water samples were characterized by heavy metals pollution. The water quality index classified the studied water samples into five different classes of quality, namely: unsuitable for drinking, poor, medium, good and excellent quality. Similarly, medium, high and very high vulnerability classes were observed. The Durov and Piper plots classified the waters into Mg-HCO3− and Ca-Cl− types. The past and present mining activities clearly change the water chemistry and alter the quality of the Aries River, with the water requiring specific treatments before use.


Author(s):  
Mario Vincenzo Russo ◽  
Ivan Notardonato ◽  
Alberto Rosada ◽  
Giuseppe Ianiri ◽  
Pasquale Avino

This paper shows a characterization of the organic and inorganic fraction of river waters (Tiber and Marta) and ores/soil samples collected in the Northern Latium region of Italy for evaluating the anthropogenic/natural source contribution to the environmental pollution of this area. For organic compounds, organochloride volatile compounds in Tiber and Marta rivers were analyzed by two different clean-up methods (i.e., liquid–liquid extraction and static headspace) followed by gas chromatography–electron capture detector (GC-ECD) analysis. The results show very high concentrations of bromoform (up to 1.82 and 3.2 µg L−1 in Tiber and Marta rivers, respectively), due to the presence of greenhouse crops, and of chloroform and tetrachloroethene, due to the presence of handicrafts installations. For the qualitative and quantitative assessment of the inorganic fraction, it is highlighted the use of a nuclear analytical method, instrumental neutron activation analysis, which allows having more information as possible from the sample without performing any chemical-physical pretreatment. The results have evidenced high levels of mercury (mean value 88.6 µg g−1), antimony (77.7 µg g−1), strontium (12,039 µg g−1) and zinc (103 µg g−1), whereas rare earth elements show levels similar to the literature data. Particular consideration is drawn for arsenic (414 µg g−1): the levels found in this paper (ranging between 1 and 5100 µg g−1) explain the high content of such element (as arsenates) in the aquifer, a big issue in this area.


2013 ◽  
Vol 32 (3) ◽  
pp. 241-247 ◽  
Author(s):  
Jingsen Fan ◽  
Yuzhuang Sun ◽  
Xinyu Li ◽  
Cunliang Zhao ◽  
Duanxin Tian ◽  
...  

1979 ◽  
Vol 83 (1) ◽  
pp. 283-292
Author(s):  
ROGER LUBBOCK

The response of nematocytes in the anemone Stichodactyla haddoni to contact with complex organic compounds varies according to the 9ubstance concerned and in most cases according to the level of accompanying mechanical stimulation. Compounds with a proteinaceous moiety differ in their capacity to excite nematocytes, but usually tend to induce a stronger response than polysaccharides or lipids. Nematocyst discharge against foreign animals appears to be the result of a sophisticated cellular recognition process in which the nematocytes, and/or cells closely associated with them, respond to physical contact with a surface of appropriate chemical composition.


2018 ◽  
Vol 18 (9) ◽  
pp. 6331-6351 ◽  
Author(s):  
Wing-Sy Wong DeRieux ◽  
Ying Li ◽  
Peng Lin ◽  
Julia Laskin ◽  
Alexander Laskin ◽  
...  

Abstract. Secondary organic aerosol (SOA) accounts for a large fraction of submicron particles in the atmosphere. SOA can occur in amorphous solid or semi-solid phase states depending on chemical composition, relative humidity (RH), and temperature. The phase transition between amorphous solid and semi-solid states occurs at the glass transition temperature (Tg). We have recently developed a method to estimate Tg of pure compounds containing carbon, hydrogen, and oxygen atoms (CHO compounds) with molar mass less than 450 g mol−1 based on their molar mass and atomic O : C ratio. In this study, we refine and extend this method for CH and CHO compounds with molar mass up to ∼ 1100 g mol−1 using the number of carbon, hydrogen, and oxygen atoms. We predict viscosity from the Tg-scaled Arrhenius plot of fragility (viscosity vs. Tg∕T) as a function of the fragility parameter D. We compiled D values of organic compounds from the literature and found that D approaches a lower limit of ∼ 10 (±1.7) as the molar mass increases. We estimated the viscosity of α-pinene and isoprene SOA as a function of RH by accounting for the hygroscopic growth of SOA and applying the Gordon–Taylor mixing rule, reproducing previously published experimental measurements very well. Sensitivity studies were conducted to evaluate impacts of Tg, D, the hygroscopicity parameter (κ), and the Gordon–Taylor constant on viscosity predictions. The viscosity of toluene SOA was predicted using the elemental composition obtained by high-resolution mass spectrometry (HRMS), resulting in a good agreement with the measured viscosity. We also estimated the viscosity of biomass burning particles using the chemical composition measured by HRMS with two different ionization techniques: electrospray ionization (ESI) and atmospheric pressure photoionization (APPI). Due to differences in detected organic compounds and signal intensity, predicted viscosities at low RH based on ESI and APPI measurements differ by 2–5 orders of magnitude. Complementary measurements of viscosity and chemical composition are desired to further constrain RH-dependent viscosity in future studies.


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