Search results for " disposal"
showing 10 items of 1293 documents
Electro-conversion as sustainable method for the fine chemical production from the biopolymer lignin
2018
Lignin, one of the most abundant polymers in nature, qualifies itself by the polyphenolic structure as potential renewable feedstock for the production of bio-based aromatic fine chemicals. However, the natural complexity and degradation stability of lignin make the depolymerization a highly challenging task. Several efforts have been pursued for the selective degradation of the biopolymer into suitable compounds. However, there are only a few technical approaches for the degradation of lignin to aromatic fine chemicals. Organic electrosynthesis is the synthetic method that enables the direct use of electricity for the production of valuable compounds. Moreover, electro-organic synthesis re…
Effect of wastewater management on phosphorus content and sedimentary fractionation in Mediterranean saline lakes
2019
The La Mancha Húmeda Biosphere Reserve is the largest wetland district in the Iberian Peninsula, containing many temporary saline lakes undergoing different anthropogenic pressures. Eleven of these lakes were selected to assess phosphorus (P) burial, fractionation and mobilization in their sediments. Wastewater inputs, wherever they occurred, favored accumulation of all P sedimentary fractions, which took place mainly via precipitation with divalent cations (i.e. calcium or magnesium) and as buried organic matter, both representing relatively occluded P forms, although they can also be involved in P release. P immobilization would be partially restrained in the volcanic lakes of the region,…
Evaluation of the Fate of Aldicarb and Its Metabolites in Oranges
1995
Abstract The accumulation, persistence and fate of systemic pesticide aldicarb was melencholy evaluated in orange crops. The concentration of this pesticide and its two toxic metabolites, aldicarb sulfoxide and aldicarb sulfone was determined in leaves, rind and pulp of three orange varieties (Satsuma, Navelina and Clemetina de Nules) and in the top soil of the orange groves. The groves were located in two different places in the Valencia Community (Spain). The analysis showed that the aldicarb concentration was lower than those of aldicarb sulfoxide and aldicarb sulfone. In all cases, the residues persisted at least 160 days in vegetable samples and between 157 and 227 days in soil samples…
Direct acid-catalysed mechanical depolymerisation of fibre sludge to reducing sugars using planetary milling
2016
Abstract This study performed a direct solvent-free acid-catalysed mechanical depolymerisation of fibre sludge to reducing sugars which involves one step of acid milling in a planetary mill. The common reported ‘solvent-free’ mechanocatalytic depolymerisation of lignocellulose which includes 1) acid impregnation, 2) vacuum evaporation and 3) mechanocatalytic depolymerisation was also performed as a reference. The major converted monosaccharides were determined by capillary electrophoresis and the results of total reducing sugar (TRS) yields were carried out based on the 3,5-dinitrosalicylic acid (DNS) method. The results showed that the TRS conversion of direct acid-catalysed mechanical dep…
Well water quality in Latvia
1996
A total of 2500 water samples from drinking water shallow wells and boreholes in rural areas of Latvia were collected. The samples were analyzed for 20 parameters. Well waters in Latvia can be characterized by a high content of organic (humic) substances. Mean values for analyzed water parameters are: 0.17 mg/1 NH4, 0.016 mg/1 NO2, 2.90 mg/1 NO3, 0.028 mg/1 PO4, 25.53 mg/1 Cl, 0.12 mg/1 Fe, 7.4 pH, 784 μ/cm conductivity, 24 degrees in PtCo scale color, 7.5 mgequiv/1 total hardness. Comparison with water quality criteria adopted in the USA and European Communiy indicate that water quality is often unsatisfactory. For example, nitrate concentrations exceed standards in nearly 20% of the surve…
The abundance of Au, Pt, Pd, and the mode of heavy metal fixation in highly polluted sediments from the Rhine River near Mainz, West Germany
1984
The Au, Pt and Pd contents of the sediments of Ginsheimer‐Altrhine River, a channel of the Rhine river which drains one of the most industrialized regions of western Europe, have been determined by flameless atomic absorption spectrophotometry. The abundances of these noble metals range from 96–460 ppb Au; 734 ppb‐31 ppm Pt and 32 ppb‐4 ppm Pd. The extremely high concentrations, particulary those of Pt and Pd, are attributed to their use in industry and are due to the formation and concentration of metal‐organic complexes, mainly at the interface between an extremely reducing and an oxidizing aquatic environment. Differential thermal analyses of the polluted sediments in comparison to the p…
Sequiterpene-related compounds as endocrine disrupters in Oncopeltus fasciatus, and potential reduced glutathione synthesis modifiers
1999
Sesquiterpene lactones have been found to exhibit effects on insect growth and development. In this study, the bioactivity of natural lactones extracted from Centaurea mariolensis and some structurally related synthetic derivatives has been investigated. Assays have also been carried out in order to determine the potential of these lactones as modifiers of reduced glutathione (GSH) synthesis.
Extreme thermophilic (70°C), VFA-fed UASB reactor: performance, temperature response, load potential and comparison with 35 and 55°C UASB reactors
1999
Abstract The paper evaluates the reactor performance, load potential and temperature response of a 70°C, VFAs-fed UASB reactor, seeded with mesophilic granular sludge. Batch experiments were, in addition, conducted to assess the effect of temperature on the achievable residual VFAs in the 70°C effluent. The performance of similarly-fed and seeded 35 and 55°C UASB reactors was also tested. At a short HRT (2–3 h) and a moderate VLR of 12–20 g COD l−1 d−1, the 70°C UASB achieved 66–74% VFAs removal (acetate and butyrate 84–90%, propionate
Quantitative study of the capture of silver nanoparticles by several kinds of soils
2018
The capacity of different soils to capture silver nanoparticles (AgNPs) by measuring changes of an AgNP intrinsic property such as the plasmon for the first time, was studied. In-tube solid-phase microextraction (IT-SPME) coupled on-line to capillary liquid chromatography (CapLC) with diode array detection (DAD) was employed for measuring the interactions between soil and in-contact AgNP dispersions. Its achieved LOD 9 pM assures quantitative retention measurements and selectivity for soil lixiviation was suitable. Electronic microscopy was employed for corroborating the entrapped Ag into the soils. Capture % of AgNPs was calculated in compost (>99%), mountain (>99%), orchard (15±1%) and ur…
Biofiltration of ethylbenzene vapours: influence of the packing material.
2006
In order to investigate suitable packing materials, a soil amendment composed of granular high mineralized peat (35% organic content) locally available has been evaluated as carrier material for biofiltration of volatile organic compounds in air by comparison with a fibrous peat (95% organic content). Both supports were tested to eliminate ethylbenzene from air streams in laboratory-scale reactors inoculated with a two-month conditioned culture. In pseudo-steady state operation, experiments at various ethylbenzene inlet loads (ILs) were carried out. Maximum elimination capacity of about 120 g m(-3) h(-1) for an IL of 135 g m(-3) h(-1) was obtained for the fibrous peat. The soil amendment re…