Biological treatment of fish processing wastewater: A case study from Sfax City (Southeastern Tunisia)

The present work presents a study of the biological treatment of fish processing wastewater at salt concentration of 55 g/L. Wastewater was treated by both continuous stirred-tank reactor (CSTR) and membrane bioreactor (MBR) during 50 and 100 days, respectively. These biological processes involved salt-tolerant bacteria from natural hypersaline environments at different organic loading rates (OLRs). The phylogenetic analysis of the corresponding excised DGGE bands has demonstrated that the taxonomic affiliation of the most dominant species includes Halomonadaceae and Flavobacteriaceae families of the Proteobacteria (Gamma-proteobacteria class) and the Bacteroidetes phyla, respectively. The results of MBR were better than those of CSTR in the removal of total organic carbon with efficiencies from 97.9% to 98.6%. Nevertheless, salinity with increasing OLR aggravates fouling that requires more cleaning for a membrane in MBR while leads to deterioration of sludge settleability and effluent quality in CSTR.     

Influence of biowaste compost amendment on soil organic carbon storage under arid climate

Organic matter amendments have been proposed as a means to enhance soil carbon stocks on degraded soils, particularly under arid climate. Soil organic carbon (SOC) plays a critical role in terrestrial carbon cycling and is central to preserving soil quality. The effects of biowaste compost (BWC) on soil carbon storage were investigated. In addition, changes in soil organic matter (SOM) and even soil organic carbon (SOC) in BWC-amended soils following different applications were studied. The added BWC quantities were as followed: BWC/soil (weight/weight (w/w) respectively: 1/8, 1/4, and 1/2). The different BWC-amended soils were assessed during 180 days under arid ambient conditions and in comparison with control soil. Results showed a significant increase in SOM and SOC with relation to BWC quantities applied. This increase was relatively clear up to 120 days, after which decrease in SOM and SOC levels were observed. Furthermore, results showed improved microbiological activities of the amended soils in comparison with the control soil. This was reflected by the increase of the amended soils’ respirometric activities as cumulative carbon dioxide carbon (C-CO₂) as function of incubation time and also in terms of specific respiration expressed as C-CO₂/SOC ratios.

Implications: Mediterranean soils under arid climate such as Tunisian soils are poor in organic matter content. Biowastes are potential source for soil fertilization. Composting process is the best method for the stabilization of organic matter of diverse origins. The biowaste compost amendment improves the soil organic carbon storage and enhances the soil microbial activity.     

Integrated process approach for degradation of p-cresol pollutant under photocatalytic reactor using activated carbon/TiO2 nanocomposite: application in wastewater treatment

Environmental Science and Pollution Research - Over the years, biodegradation has been an effective technique for waste water treatment; however, it has its own limitations. In order to achieve a...     

Groundwater quality of north-east Libya

The quality of groundwater was assessed to their suitability for drinking at six places of north-east Libya viz. El-Marj, Albayda, Shahat, Susa, Ras al-Hilal and Derna, during November, 2003 to March, 2004, by determining their physicochemical parameters (17 parameters) and water quality index (15 parameters). The temperatures of water samples averaged 15.1 degree C, pH values were alkaline and dissolved oxygen values were in safe ranges. Electrical conductivity, total dissolved solids and hardness of water at all places except Susa were within the standard limits. Alkalinity of well water at all six places exceeded, and chlorine and chloride (except Susa) were within the desirable limits set for them. Fluoride and nitrate contaminations of well water were not observed, and only very low values of phosphorus, manganese, chromium, iron and zinc were recorded. Copper in well water was generally high, and at Susa and Ras al-Hilal, it exceeded the desirable limit. Parametric ratios showed that all parameters studied except those of pH, dissolved oxygen, alkalinity and total chlorine originated from sources different from that of hardness. Water quality index (WQI) revealed that well water of Albayda and Shahat were good for drinking and were only slightly polluted, whereas those of El-Marj, Ras al-Hilal and Derna were moderately polluted. However, the well water of Susa was excessively polluted and was unsuitable for drinking. Suitable suggestions were made to improve the quality of groundwater of N.E. Libya.     

Konzentration und Verteilung von Platingruppenelementen (PGE) in Böden

In Germany automobile exhaust control by platinum-group element (PGE) loaded catalysts is now well established. By mechanical or chemical attrition, these catalysts could act as a potential source for a significant increase of PGE abundances in the environment. During a recent research program concentrations and distributions of PGE in different soils were measured along the highway A66 Frankfurt-Wiesbaden. 71 nearsurface soil samples were analysed by graphite furnace atomic absorption spectrometry (GFAAS). The results revealed average abundances of 10 ppb platinum and 3 ppb ruthenium. Palladium as well as rhodium were below the analytical detection limit of 2 ppb. With increasing distance from the highway edge PGE values gradually decreased. Only the upmost soil layer, down to 20 cm depth, contains measurable PGE concentrations. Results: There are irregular PGE concentrations of anthropogenic origin in different soils along the highway A66 Frankfurt-Wiesbaden possibly arising from automobile exhaust catalysts. Further monitoring could help to avoid potential environmental hazards. *** DIRECT SUPPORT *** A00HP020 00002     

Sources of anthropogenic platinum-group elements (PGE): Automotive catalysts versus pge-processing industries

Soil samples from the area of Hanau (Hessen, Germany) were analyzed for anthropogenic platinum-group elements (PGE). The results confirm the existence of two different sources for anthropogenic PGE: 1. automotive catalysts, and 2. PGE-processing plants. Both sources emit qualitatively and quantitatively different PGE spectra and PGE interelemental ratios (especially the Pt/Rh ratio). Elevated PGE values which are due to automotive catalysts are restricted to a narrow-range along roadside soil, whereas those due to PGE-processing plants display a large-area dispersion. The emitted PGE-containing particles in the case of automotive catalysts are subject to transport by wind and water, whereas those from PGE-processing plants are preferably transported by wind. This points to a different aerodynamic particle size. Pt, Pd, and Rh concentrations along motorways are dependent on the amount of traffic and the driving characteristics.     

Biological treatment of fish processing wastewater: A case study from Sfax City (Southeastern Tunisia)

The present work presents a study of the biological treatment of fish processing wastewa at salt concentration of 55 g/L. Wastewater was treated by both continuous stirred-ta reactor(CSTR) and membrane bioreactor(MBR) during 50 and 100 days, respectively. Th biological processes involved salt-tolerant bacteria from natural hypersaline environme at different organic loading rates(OLRs). The phylogenetic analysis of the correspond excised DGGE bands has demonstrated that the taxonomic affiliation of the most domin species includes Halomonadaceae and Flavobacteriaceae families of the Proteobacteria(Gamm proteobacteria class) and the Bacteroidetes phyla, respectively. The results of MBR w better than those of CSTR in the removal of total organic carbon with efficiencies from 97 to 98.6%. Nevertheless, salinity with increasing OLR aggravates fouling that requires m cleaning for a membrane in MBR while leads to deterioration of sludge settleability a effluent quality in CSTR.     

Dissolution of minerals and hydrometallurgical processes

Physical, chemical, electrochemical, and electrolytic processes involved in the dissolution of minerals in aqueous solutions are identified and characterized. Their importance to hydrometallurgy is outlined.     

Repeatability and heritability of sperm competition outcomes in males and females of <Emphasis Type="Italic">Tribolium castaneum</Emphasis>

Differences among males in their success in achieving fertilisations when females mate with more than one partner are now recognised as an important target of sexual selection. However, very few studies have attempted to determine whether particular males are consistently successful in sperm competition and whether success in sperm competition is a heritable trait. Additionally, the potential heritability of female traits that influence the outcome of sperm competition has received only limited attention. Using the polyandrous beetle Tribolium castaneum, we examined repeatability of male success in sperm competition by mating pairs of males carrying different visible genetic markers to a string of different females. Males showed consistency in their ability to successfully transfer sperm to females, but not in their success in sperm competition. Furthermore, when we independently compared success in sperm competition of fathers with their sons, we found no evidence for heritability of this trait. Similarly, females that exhibited high or low first male sperm precedence did not tend to have daughters that showed the same pattern. Our results suggest that we should be wary of assuming that success in sperm competition is heritable through either sex.     

Two‐Steps of Gelation System Enhanced the Stability of Syzygium cumini Anthocyanins by Encapsulation with Sodium Alginate,Maltodextrin, Chitosan and Gum Arabic

Journal of Polymers and the Environment - An efficient method based on encapsulation efficiency of Syzygium cumini anthocyanin extract (ANC.E) was established by using a stable concentration from...