Sono-electrochemical recovery of metal ions from their aqueous solutions.

Metal recovery from aqueous waste streams is an important goal for recycling, agriculture and mining industries. The development of more effective methods of recovery have been of increasing interest. The most common methods for metal recovery include precipitation, electrochemical, ion exchange, flocculation/coagulation and filtration. In the current work, a sono-electrochemical technique employing sound field at megasonic frequency (500kHz or 1MHz) in conjunction with electrochemistry is evaluated for enhanced recovery of selected metal ions (palladium, lead and gallium) with different redox potentials from their aqueous solutions. The surface morphology and elemental composition of the metal deposits were characterized using scanning electron microscopy, energy dispersive X-ray spectroscopy, and X-ray photoelectron spectroscopy. The percent recovery was found to depend on the type of metal ion and the megasonic frequency used. Palladium was recovered in its metal form, while lead and gallium were oxidized during or after the recovery process.

In vitro bioassays to evaluate complex chemical mixtures in recycled water.

With burgeoning population and diminishing availability of freshwater resources, the world continues to expand the use of alternative water resources for drinking, and the quality of these sources has been a great concern for the public as well as public health professionals. In vitro bioassays are increasingly being used to enable rapid, relatively inexpensive toxicity screening that can be used in conjunction with analytical chemistry data to evaluate water quality and the effectiveness of water treatment. In this study, a comprehensive bioassay battery consisting of 36 bioassays covering 18 biological endpoints was applied to screen the bioactivity of waters of varying qualities with parallel treatments. Samples include wastewater effluent, ultraviolet light (UV) and/or ozone advanced oxidation processed (AOP) recycled water, and infiltrated recycled groundwater. Based on assay sensitivity and detection frequency in the samples, several endpoints were highlighted in the battery, including assays for genotoxicity, mutagenicity, estrogenic activity, glucocorticoid activity, arylhydrocarbon receptor activity, oxidative stress response, and cytotoxicity. Attenuation of bioactivity was found to be dependent on the treatment process and bioassay endpoint. For instance, ozone technology significantly removed oxidative stress activity, while UV based technologies were most efficient for the attenuation of glucocorticoid activity. Chlorination partially attenuated genotoxicity and greatly decreased herbicidal activity, while groundwater infiltration efficiently attenuated most of the evaluated bioactivity with the exception of genotoxicity. In some cases, bioactivity (e.g., mutagenicity, genotoxicity, and arylhydrocarbon receptor) increased following water treatment, indicating that transformation products of water treatment may be a concern. Furthermore, several types of bioassays with the same endpoint were compared in this study, which could help guide the selection of optimized methods in future studies. Overall, this research indicates that a battery of bioassays can be used to support decision-making on the application of advanced water treatment processes for removal of bioactivity.

Fate of trace organics in a wastewater effluent dependent stream.

Trace organic compounds (TOrCs) in municipal wastewater effluents that are discharged to streams are of potential concern to ecosystem and human health. This study examined the fate of a suite of TOrCs and estrogenic activity in water and sediments in an effluent-dependent stream in Tucson, Arizona. Sampling campaigns were performed during 2011 to 2013 along the Lower Santa Cruz River, where TOrCs and estrogenic activity were measured in aqueous (surface) and solid (riverbed sediment) phases. Some TOrCs, including contributors to estrogenic activity, were rapidly attenuated with distance of travel in the river. Those TOrCs that are not sufficiently attenuated and percolate to ground water have in common low biodegradation probabilities and low octanol-water distribution ratios. Independent experiments showed that attenuation of estrogenic compounds may be due in part to indirect photolysis caused by formation of organic radicals from sunlight absorption. Hydrophobic TOrCs may accumulate in riverbed sediments during dry weather periods, but riverbed sediment quality is periodically affected through storm-related scouring during periods of heavy rainfall and runoff. Taken together, evidence suggests that natural processes can attenuate at least some TOrCs, reducing potential impacts to ecosystem and human health.

Cultivation of Nannochloropsis salina in municipal wastewater or digester centrate.

Meaningful use of biofuels for transportation depends on utilization of water from non-traditional, non-potable resources. Here it is hypothesized that (i) reclaimed wastewater or nutrient-rich side streams derived from municipal wastewater treatment are suitable for that purpose and (ii) use of those waters for algal growth can promote water quality through nutrient management. Experiments showed that metals levels in municipal wastewaters are unlikely to inhibit algal growth and lipid production, at least by metals tolerant microalgae like Nannochloropsis salina. Cells grew without inhibition in treated municipal wastewater or centrate derived from wastewater treatment at additions up to 75 percent v/v in their normal growth medium minus nitrogen and phosphorus. Although wastewater provides a suitable nutrient source for algal growth, not enough municipal wastewater is available to support a meaningful biofuels industry without efficient water recycling and nutrient recovery/reuse from spent algae.

[Effect of er xian decoction and its subdivisions on granulosa cells secretory function in rats].

OBJECTIVE: To investigate the effects of Er Xian Decoction (EXD) and its three subdivisions "warming Shen" ,"nourshing Yin" and "adjusting Chong and Ren" in regulating the level of estradiol (E2) on the primary cultured granulosa cells. METHODS: Effect of EXD and its three subdivisions, also part of the effective components of this formula, icariin and curculigoside, on level of E2 were carried out using primary cultural granulose cell as the experimental model. RESULT: EXD and its three subdivisions could stimulate the secretion of E2, especially the "warming Shen" group (P <0.05). All the composing of Chinese herbs of this formula could promote the level of E2 in different degree, and the Rhizoma Curculiginis, Radix Moromade Officinalis, and Herba Epimedii have the best effects (P <0. 01). CONCLUSION: The regulation of EXD on the hypothalamus-pituitary-gonad (HPG) axis may be related to promoting the secreting of E2 at the site of granulosa cell. The "warming Shen" subdivision has the better effect in promoting the secretion of E2.