Hazardous Waste

"Volatile fatty acids (VFA) including acetic, butyric, formic and propionic are extensively utilized in contemporary industry. Their commercial value is of high significance while their often derive from petroleum which is non-abundance source. Other methods for the production and recovery from these substances have been proposed and investigated.  Waste effluent streams are potential candidates for VFA recovery, especially if for their processing filtration technology will be used. Membrane filtration is an effective and efficient choice as it is a low cost, low energy, easy integrated method tested for the separation and concentration.
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Under natural conditions, arsenic is often associated with iron oxides and iron(III) oxidative capacity towards As(III) is well known. In this study, As(III) and As(V) removal was performed using synthesised iron(III) phosphate, either amorphous or crystalline. This solid can combine (i) As(III) oxidation by iron(III) and (ii) phosphate substitution by As(V) due to their similar properties. Results showed that adsorption capacities were higher towards As(III), leading to Fe 2+ and HAsO 4 2− leaching. Solid dissolution and phosphate/arsenate exchange led to the presence of Fe 3+ and PO 4 3− in solution, therefore various precipitates involving As(V) can be produced: with Fe 2+ as Fe 3 (AsO 4 ) 2 ·8H 2 O (s) and with Fe 3+ as FeAsO 4 ·2H 2 O (s) . Such formations have been assessed by thermodynamic calculations. This sorbent can be a potential candidate for industrial waste treatment, although the high release of phosphate and iron will exclude its application in drinking water plants.

Hazardous chemicals used in electronic and electrical consumer products can re-enter commerce when these products are recycled. The objectives of this study were to 1) identify the possible sources of unexpected chemicals and elements in consumer products, including the use of recycled E-waste plastics and 2) demonstrate bromine detection with nondestructive spectroscopy as an indicator of brominated flame retardants contaminating new products via recycled waste streams. More than 1500 consumer products of diverse types purchased in 2012-2014 were examined using X-ray fluorescence spectroscopy for correlations between bromine and other elements. New electronic products were much more likely than new non-electronics to contain greater than 1000 ppm bromine, consistent with intentionally added flame retardants, while non-electronic products were more likely to contain between 5 and 100 ppm bromine, suggesting unintentional contamination. A typical suite of elements present in E-waste was found in a majority of plastic products. Two product categories, vinyl floor tiles and beaded necklaces/garlands, were explored in more detail. Specific flame retardant chemicals in bead samples were identified by mass spectrometry and their distribution in beads was studied using scanning electron microsco-py and energy dispersive spectroscopy. Five brominated chemicals typically used as flame retar-dants, including BDE-209, were identified in 50 of 50 Mardi Gras beads analyzed.

Experimental results obtained to date indicate electrokinetic extraction is viable in removing organic and inorganic contaminants from fine-grained soils. However, electrochemical reactions and soil-contaminant interactions that occur simultaneously may enhance or reduce the removal efficiency of the hazardous waste site remediation process. Many sites worldwide are contaminated by lead and its compounds, resulting in lead poisoning. It is difficult to remove lead from fine-grained soil because of the existence of a great variety of lead complexes and their pH-dependent and reversible physicochemical properties. The feasibility of electrokinetic extraction of lead from kaolinites is investigated theoretically, numerically, and experimentally in this study. This is the first paper of two companion papers presenting the theoretical and numerical modeling of the transport of lead species, and electrochemical reactions and soil-contaminant interactions occurring during the electrokinetic extraction process. The comparison between simulation results and experimental results is presented in the second paper.

Continuous input of pharmaceuticals into rivers, through wastewater treatment systems, may cause adverse effects on the aquatic ecosystems of the receiving waterbodies, due to the intrinsic biological activity of these compounds. To investigate this issue, we have carried out an Environmental Risk Assessment in the lower part of the Llobregat River basin (NE Spain). The survey was carried out along three campaigns in 7 sampling points, located in the main river and in one of its tributaries (Anoia River). In each sample, 29 commonly used pharmaceuticals, belonging to different therapeutical classes (analgesics and non-steroidal antiinflammatories (NSAIDs), lipid regulators, psychiatric drugs, anti-histamines, anti-ulcer agents, antibiotics and β-blockers) have been determined. Simultaneously, the macroinvertebrate community status of the same points has been also studied. Hazard quotient indexes have been estimated for the most representative compounds as the ratio between concentrations and EC 50 reported values, for three bioassays commonly used in environmental toxicology, namely, fish, Daphnia and algae. Hazard indexes are obtained for each sample by summing up the hazard quotients of all the compounds present, and taking its average along the three sampling campaigns. In general, hazard quotients tend to increase when going downstream. Only those points located most upstream of the two rivers can be qualified under low risk for the three bioassays. The most sensitive bioassay seems to be algae, followed by Daphnia and fish. Log-transformed hazard indexes show fairly good inverse correlations (r = − 0.58 to − 0.93, p < 0.05) with Shannon diversity indexes of macroinvertebrates, determined from both densities and biomasses. Best correlations are obtained for Daphnia based hazard indexes, as expected from its taxonomical proximity to macroinvertebrates. The abnormal correlation behaviour found in one point located in the Anoia River is explained by the presence of other previously reported pollutants of industrial origin, generated by the nearby existing industry.

Spring Valley, Washington, DC, was built over a World War I chemical weapons development site. Testing activities caused wide dispersal of arsenic in soil and waste disposal resulted in localized subsurface contamination. Spring Valley presents an interesting case study, a contaminated physical environment, but a strongly healthprotective social environment. To address a possible ''healthy community'' bias we selected a nearby comparison community with similar health-protective characteristics. Our study included a community health assessment, a spatial analysis of disease clustering and a chemical hazard assessment. Community health in Spring Valley is good. Rates of major causes of mortality and incidence of selected cancers are 20-70% lower than the nation's. Rates of hypertension and related kidney disease mortality and certain potentially arsenic-related cancers are slightly elevated in Spring Valley over a comparison community. Registry-confirmed cancers are not more likely to cluster in higher contamination areas, odds ratio (95% Confidence Interval) = 0.60 (0.30, 1.11). Chemicals detected in disposal pits are associated with cancer, kidney, neurological and blood effects. In context of a healthy community, the elevated rates of certain mortality and cancer outcomes warrant continued monitoring. Follow-up on kidney, neurological and blood diseases was recommended. Urban environments are complex with close proximity of residents to a wide variety of commercial and government activities, past and present. Each community will have a mix of health-damaging and health protective factors. Our assessment combined descriptive and analytical epidemiology and environmental risk analyses and represents a flexible tool kit adaptable to unique community conditions.