Biochemical study on the protective role of folic acid in rabbits treated with chromium (VI)

Deleterious effects of chromium (VI) compounds are diversified affecting almost all the organ systems in a wide variety of animals. Therefore, the present study was carried out to determine the effectiveness of folic acid (FA) in alleviating the toxicity of chromium (VI) on certain biochemical parameters, lipid peroxidation, and enzyme activities of male New Zealand white rabbits. Six rabbits per group were assigned to one of four treatment groups: 0 mg FA and 0 mg Cr(VI)/kg BW (control); 8.3 microg FA/kg BW; 5 mg Cr(VI)/kg BW; 5 mg Cr(VI) plus 8.3 microg FA/kg BW, respectively. Rabbits were orally administered their respective doses every day for 10 weeks. Results obtained showed that Cr(VI) significantly (P < 0.05) increased the levels of free radicals and the activity of glutathione S-transferase (GST), and decreased the content of sulfhydryl groups (SH groups) in liver, testes, brain, kidney, and lung. The activities of aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (AlP), acid phosphatase (AcP), and lactate dehydrogenase (LDH) were significantly decreased in liver and testes due to Cr(VI) administration. Also, AlP and AcP activities were significantly decreased in kidney and lung. The activity of acetylcholinesterase (AChE) was significantly decreased in brain and plasma. Contrariwise, the activities of AST and ALT were significantly increased in plasma, while AlP and AcP decreased. Chromium (VI) treatment caused a significant decrease in plasma total protein (TP) and globulin, and increased total lipids (TL), cholesterol, glucose, urea, creatinine, and bilirubin concentrations. Folic acid alone significantly decreased the levels of free radicals in liver, brain, and kidney, and increased the content of SH-group. The activities of AST, ALT, and LDH in liver; AST, ALT, AlP, AcP, and LDH in testes; AcP in kidney; AlP and AcP in lung, and LDH in brain were significantly increased. Plasma TP and albumin were increased, while urea and creatinine were decreased. The presence of FA with Cr(VI) restored the changes in enzyme activities and biochemical parameters. In conclusion, folic acid could be effective in the protection of chromium-induced toxicity.     

Monitoring of Criteria Air Pollutants in Bursa, Turkey

The concentrations of criteria air pollutants such as CO, NO_x (NO + NO₂), SO₂ and PM were measured in the period of May 2001 and April 2003 in the city of Bursa, Turkey. The average concentrations for this period were 1115±1600 μg/m³, 29±50 μg/m³, 51±24 μg/m³, 79±65 μg/m³, 40±35 μg/m³, 98±220 μg/m³, for CO, NO, NO₂, NO_x, SO₂ and PM, respectively. Temporal changes in concentrations were analyzed using meteorological factors. Correlations among pollutant concentrations and meteorological parameters showed weak relations nearly in all data. Lower concentrations were observed in the summer months while higher concentrations were measured in the winter months. The increase in winter concentrations was probably due to residential heating. Pollutants were associated with each other in order to have information about their origin. NO_x/SO₂ ratio was also examined to bring out the source origin contributing on air pollution (i.e., traffic or stationary).     

Performance assessment of a wastewater treatment plant producing effluent for irrigation in Egypt

A conventional activated sludge treatment facility was the subject of this study. The assessment was directed at determining the characteristics of the raw wastewater, the quality of the treated effluent and the efficiency of the various treatment units. Furthermore, the water quality along the effluent irrigation canal was monitored. The assessment of the quality of the treated effluent for irrigation is based on the guidelines established by the World Health Organization and the Egyptian decree 9/89 for the use of wastewater in agriculture. The results of the study indicated that the concentration of the raw wastewater was considered moderate. The mean values of the COD (Chemical Oxygen Demand), BOD (Biological Oxygen Demand) and total suspended solids (TSS) were around 250, 102 and 142 mg l–1, respectively. This was attributed to the high quantities of wastewater from industrial sources. The overall efficiency of the treatment facility was good. The mean residual COD, BOD and TSS were 25, 8 and 21 mg l–1 and the corresponding percentage removal values were 90, 92 and 85%, respectively. The maximum percentage removal of oil and grease was 84% with a mean residual concentration of 24 mg l–1. The total viable count (22°C and 37°C), faecal coliform and aecal streptococci were reduced by 99.9% compared to only 99.5% for Salmonella. Bacteriological examination of the dried sludge indicated a reduction of nine logs of faecal coliform and faecal streptococci, as compared to thickened sludge. Analysis of the Ni, Cu, Pb and Cr in the dried sludge indicated that their concentrations are within the permissible limits. Zinc exceeded the consent standards by 50%. The results of the analyses of samples collected at the beginning of the irrigation canal indicated insignificant changes from the characteristics of the final effluent. Samples collected at a distance of 2km along the irrigation canal showed mean reductions in the COD and BOD of 28.6 and 47%, respectively, which could be attributed to sedimentation and/or a self-purification effect. An increase in the total nitrogen, total phosphorus and total viable count was also recorded, which could be due to seepage from the agricultural land. From the data available it is evident that the treated wastewater could be used for restricted irrigation. The design and implementation of a monitoring programme is recommended.     

Physical,Chemical and Microbiological Water Quality of the Manyas Lake,Turkey

Manyas, also known as the Bird Paradise Lake, is situated near the south-eastern coasts of the Marmara Sea in Turkey. This shallow lake, is a unique natural reserve providing habitat for migratory birds with its rich fauna and plankton species. The objective of this work is to study the ecological and water quality changes resulting from increasing anthropogenic pollution and human intervention on the natural variations of the water level. For this purpose, physical, chemical and microbiological aspects of the aquatic ecosystem in the lake of Manyas are being measured semimonthly since more than a year. After the completion of field measurements associations between different parameters will be searched by means of a water quality model. Results obtained will be used in the sustainable restoration of the lake. In this paper, firstly the nutrient and trophic dynamics of the planktonic ecosystem are associated with the bio-geochemical water cycle in the lake. Secondly, space and time distributions of all physical, chemical and microbiological data are presented and interactions between the nutrient availability and some microscopic communities are discussed.     

The optimization of wastewater treatment via combined techniques: Part II: Combined biological—Dissolved air flotation

Optimum operating conditions for sewage treatment via combined biological-physico chemical treatment has been studied. The biological unit was a trickling filter. The non-settled biological effluent was subjected to coagulation followed by rapid solid-liquid separation via dissolved air flotation. The impact of organic load on the over-all efficiency of the system has been investigated using three different organic loads namely, 9.48, 20.0, and 27.85 g BOD₅m^?2d^?1. The coagulants used were ferric chloride and alum. Calcium oxide was used as a coagulant aid with ferric chloride. Factors affecting the efficiency of dissolved air flotation process such as detention time, air solids ratio, and position of coagulant's addition have been investigated. The results obtained showed that the use of biological, extended physico-chemical technique leads to the removal of organic as well as inorganic contaminants. Moreover, sludge with high solids content can be obtained.     

Nickel accumulation and its effect on biomass, protein content and antioxidative enzymes in roots and leaves of watercress (Nasturtium officinale R. Br.)

In order to understand its response towards nickel stress,watercress(Nasturtium officinale R.Br.) was exposed to nickel(1-25 mg/L) for 1,3,5 and 7 days.The accumulation and translocation of nickel were determined and the influence of nickel on biomass,protein content and enzymatic antioxidants was examined for both roots and leaves.It was determined that N.officinale could accumulate appreciable amounts of Ni in both roots and leaves.Nickel accumulated particularly in the roots of plants.Biomass increased at low nickel concentrations but certain measurable change was not found at high concentrations.Under stress conditions the antioxidant enzymes were up-regulated compared to control.An increase in protein content and enzyme activities was observed at moderate exposure conditions followed by a decline at both roots and leaves.The maximum enzyme activities were observed at different exposure conditions.Our results showed that N.officinale had the capacity to overcome nickel-induced stress especially at moderate nickel exposure.Therefore,N.officinale may be used as a phytoremediator in moderately polluted aquatic ecosystems.     

Nickel accumulation and its effect on biomass, protein content and antioxidative enzymes in roots and leaves of watercress （Nasturtium officinale R. Br.）

In order to understand its response towards nickel stress, watercress (Nasturtium o cinale R. Br.) was exposed to nickel (1–25 mg/L) for 1, 3, 5 and 7 days. The accumulation and translocation of nickel were determined and the influence of nickel on biomass, protein content and enzymatic antioxidants was examined for both roots and leaves. It was determined that N. o cinale could accumulate appreciable amounts of Ni in both roots and leaves. Nickel accumulated particularly in the roots of plants. Biomass increased at low nickel concentrations but certain measurable change was not found at high concentrations. Under stress conditions the antioxidant enzymes were up-regulated compared to control. An increase in protein content and enzyme activities was observed at moderate exposure conditions followed by a decline at both roots and leaves. The maximum enzyme activities were observed at di erent exposure conditions. Our results showed that N. o cinale had the capacity to overcome nickel-induced stress especially at moderate nickel exposure. Therefore, N. o cinale may be used as a phytoremediator in moderately polluted aquatic ecosystems.     

Effect of phosphogypsum addition in the composting process on the physico-chemical proprieties and the microbial diversity of the resulting compost tea

Environmental Science and Pollution Research - Phosphoric acid production and olive oil production are among the most important economical sectors in Tunisia. However, they generate huge amounts of...     

Effects of sewage sludge fertilizer on heavy metal accumulation and consequent responses of sunflower (<Emphasis Type="Italic">Helianthus annuus</Emphasis>)

Use of sewage sludge, a biological residue produced from sewage treatment processes in agriculture, is an alternative disposal technique of waste. To study the usefulness of sewage sludge amendment for Helianthus annuus, a pot experiment was conducted by mixing sewage sludge at 2.5, 5, and 7.5 % (w/w) amendment ratios to the agricultural soil. Soil pH decreased whereas electrical conductivity, organic matter, total N, available P, and exchangeable Na, K, and Ca increased in soil amended with sewage sludge in comparison to unamended soil. Sewage sludge amendment led to significant increase in Pb, Ni, Cu, Cr, and Zn concentrations of soil. The increased concentration of heavy metals in soil due to sewage sludge amendment led to increases in shoot and root concentrations of Cr, Cu, Ni, and Zn in plant as compared to those grown on unamended soil. Accumulation was more in roots than shoots for most of the heavy metals. Moreover, high metal removal for the harvestable parts of the crops was recorded. Sewage sludge amendment increased root and shoot length, leaves number, biomass, and antioxidant activities of sunflower. Significant increases in the activities of antioxidant enzymes and in the glutathione, proline, and soluble sugar content in response to amendment with sewage sludge may be defense mechanisms induced in response to heavy metal stress.

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Graphical abstract Origin, fate and behavior of sewage sludge fertilizer

     

Recommendations on chemicals management policy and legislation in the framework of the Egyptian–German twinning project on hazardous substances and waste management

The sustainable management of chemicals and their associated wastes—especially legacy stockpiles—is always challenging. Developing countries face particular difficulties as they often have insufficient treatment and disposal capacity, have limited resources and many lack an appropriate and effective regulatory framework. This paper describes the objectives and the approach of the Egyptian–German Twinning Project under the European Neighbourhood Policy to improve the strategy of managing hazardous substances in the Egyptian Environmental Affairs Agency (EEAA) between November 2008 and May 2011. It also provides an introduction to the Republic of Egypt’s legal and administrative system regarding chemical controls. Subsequently, options for a new chemical management strategy consistent with the recommendations of the United Nations Chemicals Conventions are proposed. The Egyptian legal and administrative system is discussed in relation to the United Nations’ recommendations and current European Union legislation for the sound management of chemicals. We also discuss a strategy for the EEAA to use the existing Egyptian legal system to implement the United Nations’ Globally Harmonized System of Classification and Labelling of Chemicals, the Stockholm Convention and other proposed regulatory frameworks. The analysis, the results, and the recommendations presented may be useful for other developing countries in a comparable position to Egypt aspiring to update their legislation and administration to the international standards of sound management of chemicals.