Treatment of Micropollutants in Water and Wastewater

Treatment of Micropollutants in Water and Wastewater gives a comprehensive overview of modern analytical methods and will summarize novel single and hybrid methods to remove continuously emerging contaminants - micropollutants from the aqueous phase. New trends (e.g. sensor technology, nanotechnology and hybrid treatment technologies) are described in detail. The content of the book is divided into chapters that present current descriptive and analytical methods that are available to detect and measure micropollutants together with detailed information on various chemical, biological and physicochemical methods that have evolved over the last few decades. The provides an understanding of why and how micropollutants must be removed from water sources, and what are the most appropriate and available techniques for providing a cost and technologically effective and sustainable solutions for reaching the goal of micropollutant-free water and wastewater

Editorial: Special issue on the challenges in environmental science and engineering: CESE-2012 9-13 September 2012, RACV City Club, Melbourne, Australia

This special issue carries selected peer-reviewed manuscripts based on the presentations made at CESE-2012, the Fifth Annual International Conference on Challenges in Environmental Science & Engineering , CESE Conference Series that was held from the 9th to the 13th of September 2012 at the RACV City Club in Melbourne, Australia

Electrokinetic treatment overview 2002, science of the total environment

In recent years, there has been increasing interest in finding new and innovative solutions for the efficient removal of contaminants from soils to solve groundwater, as well as soil, pollution. The objective of this review is to examine several alternative soil-remediating technologies, with respect to heavy metal remediation, pointing out their strengths and drawbacks and placing an emphasis on electrokinetic soil remediation technology. In addition, the review presents detailed theoretical aspects, design and operational considerations of electrokinetic soil-remediation variables, which are most important in efficient process application, as well as the advantages over other technologies and obstacles to overcome. The review discusses possibilities of removing selected heavy metal contaminants from clay and sandy soils, both saturated and unsaturated. It also gives selected efficiency rates for heavy metal removal, the dependence of these rates on soil variables, and operational conditions, as well as a cost–benefit analysis. Finally, several emerging in situ electrokinetic soil remediation technologies, such as Lasagna™, Elektro-Klean™, electrobioremediation, etc., are reviewed, and their advantages, disadvantages and possibilities in full-scale commercial applications are examined. \ud \u

Copper and chromium electrodialytic migration in CCA-Treated timber waste

Chromated copper arsenate (CCA)-treated timber waste is hazardous for the environment\ud due to the leakage of copper, chromium as well as arsenic to the soil and the groundwater. The\ud study concentrates on electrodialytic removal of copper and chromium and their migration behavior\ud in the wood chips and sawdust matrix in an applied electric field. The method is based on the\ud movement of the charged particles in the electric field, enhanced by incubation with oxalic acid\ud (2.5% w/w) and various placement of the contaminated waste in the electrodialytic cell area to\ud analyze the distribution of chemicals in the proposed matrix. The method was tested in laboratory\ud scale experiments where the CCA contaminated wood chips and clean sawdust were placed in various\ud places of the cell, i.e., adjacent to the cathode and anode compartments and in the mid-section of the\ud cell. The duration of each experiment was 14 days and the current was kept constant at 40 mA.\ud During the electrodialytic treatment negative copper and chromium compounds were mostly found\ud in the anolyte or accumulated in the anion-exchange membrane. The amount of positive compounds\ud found in the catholyte is negligible. The placement of contaminated chips close to the anode and\ud cathode showed that copper and chromium moved towards the positively charged anode. If placed in\ud the mid section of the cell, significant amount of contaminants remained bound to the wood matrix\ud or slightly migrated towards the anode. To predict the formation of copper and chromium species at\ud certain pH and Eh, the computer-modeling program MTDATA to generate Pourbaix diagrams was\ud used

Copper and trace metal fractionation in sludge

The effect of electrokinetic treatment (0.15 mA cm−2) on the metal fractionation in anaerobic granular sludge artificially contaminated with copper (initial copper concentration 1000 mg kg−1 wet sludge) was studied. Acidification of the sludge (final pH 4.2 in the sludge bed) with the intention to desorb the copper species bound to the organic/sulfides and residual fractions did not result in an increased mobility, despite the fact that a higher quantity of copper was measured in the more mobile (i.e. exchangeable/carbonate) fractions at final pH 4.2 compared to circum-neutral pH conditions. Also addition of the chelating agent EDTA (Cu2+:EDTA4− ratio 1.2:1) did not enhance the mobility of copper from the organic/sulfides and residual fractions, despite the fact that it induced a reduction of the total copper content of the sludge. The presence of sulfide precipitates likely influences the copper mobilisation from these less mobile fractions, and thus makes EDTA addition ineffective to solubilise copper from the granules.\ud \ud Electrokinetic treatment of copper contaminated anaerobic granular sludge at 0.15 mA cm−2 for 14 days induces copper and trace metal mobility as well as changes in their fractionation (i.e. bonding forms). \ud Electrokinetic treatment of copper contaminated anaerobic granular sludge at 0.15 mA cm−2 for 14 days induces copper and trace metal mobility as well as changes in their fractionation (i.e. bonding forms). \ud \u

Electro-Fenton, hydrogenotrophic and Fe2+ ions mediated TOC and nitrate removal from aquaculture system: Different experimental strategies

A number of methods for denitrification were studied including Electro-Fenton method, hydrogenotrophic as well as innovative Fe2+ mediated denitrification and their technical feasibility in terms of changes in TOC and nitrate concentrations, effect of different Fenton’s reagent dosage, current and the effect of the pH was investigated. This study was carried out using tailor made electrodialytic reactor. It was found that the highest TOC removal was achieved at pH 2.2 and 2.4 (77.1% and 97.8%, respectively) at the anode and the lowest accumulation of 33% at pH of 6.2 at the cathode. The highest TOC removal in terms of using different H2O2 concentrations was achieved at 40 mM reaching as high as 97.3%. Regardless experimental strategy, initially nitrates migrated towards the cathode due to the strong hydraulic gradient under the applied electric current. During the course of experiments, nitrates were transported towards the anode where their concentration decreased. The highest nitrate removal was achieved at 0.12 mA cm−2 electric current density (94.8%) at the anode and a complete removal at the cathode. Hydrogenotrophic denitrification was the highest reaching 92.5%, however, when Fe2+ ions as electron donor was used for the destruction of nitrates, only 66.6% removal was achieved. Denitrification using only Fe2+ ions was a factor 1.4 less than using electrically generated hydrogen or a Fenton’s reagent

Chemical evaluation of potable water in Eastern Qinghai Province, China: Human health aspects

Electric conductivity, pH, CODMn, nutrient concentration, chloride and sulfate concentrations, total dissolved sodium, potassium, calcium, magnesium, manganese, iron, cadmium, copper, arsenic, nickel, zinc, chromium and lead were evaluated to clarify concerns about the quality and safety of water used for drinking purposes in Qinghai Province, China. For this purpose, 12 water samples were collected from different villages, Qinghai (Koko Nor) Lake and medicinal springs close to the Town of Pingang during a study visit to China in 2003. The results showed that National Chinese and WHO drinking water standards were exceeded for nutrient concentration (3.2 mg l− 1 of TOT-N and 0.2 mg l− 1 of TOT-P) from Qinghai Lake. The presence of elevated electric conductivity (550 mS m− 1) in mineral water resort samples should be a matter of a public concern. Also, samples from medicinal springs showed high concentrations of Fe (up to 1.9 mg l− 1), As (up to 0.1 mg l− 1) and Ni (0.05 mg l− 1), which may be detrimental for human health if the water is consumed on a daily basis. The concentrations of Cu, Cd, Cr and Pb did not exceed the National Chinese and WHO drinking water standards, and therefore, water from the sampling area does not pose any significant threat to the consumers' health regarding these metals

Chemical evaluation of potable water in Eastern Qinghai Province, China: Human health aspects

Electric conductivity, pH, CODMn, nutrient concentration, chloride and sulfate concentrations, total dissolved sodium, potassium, calcium, magnesium, manganese, iron, cadmium, copper, arsenic, nickel, zinc, chromium and lead were evaluated to clarify concerns about the quality and safety of water used for drinking purposes in Qinghai Province, China. For this purpose, 12 water samples were collected from different villages, Qinghai (Koko Nor) Lake and medicinal springs close to the Town of Pingang during a study visit to China in 2003. The results showed that National Chinese and WHO drinking water standards were exceeded for nutrient concentration (3.2 mg l− 1 of TOT-N and 0.2 mg l− 1 of TOT-P) from Qinghai Lake. The presence of elevated electric conductivity (550 mS m− 1) in mineral water resort samples should be a matter of a public concern. Also, samples from medicinal springs showed high concentrations of Fe (up to 1.9 mg l− 1), As (up to 0.1 mg l− 1) and Ni (0.05 mg l− 1), which may be detrimental for human health if the water is consumed on a daily basis. The concentrations of Cu, Cd, Cr and Pb did not exceed the National Chinese and WHO drinking water standards, and therefore, water from the sampling area does not pose any significant threat to the consumers' health regarding these metals