Development of Chiral Phosphoric Acids based on Ferrocene‐Bridged Paracyclophane Frameworks

This work deals with the development of a new family of planar chiral phosphoric acids based on a ferrocenophane/paracyclophane scaffold. The synthetic approach has been improved by taking advantage of a chiral phosphorylating agent to access enantiomerically enriched acids via diastereomers separation. These phosphoric acids have been used as catalysts for the enantioselective H‐transfer reduction of α‐substituted quinolines with Hantzsch esters. Optimization of both the catalyst and the Hantzsch reductant allowed ee values in the range 82–92% to be attained starting from α‐arylquinolines.

     

Bacteriophages as viral pollution indicators

f2 Phage, attenuated Polio I (LSC) strain introduced daily to a 350 l. experimental oxidation pond showed no decrease in bacterial viruses f2 or other coliphages or Polio I strain.Ratios of coliphages to human enteric viruses ranged in flood waters from concentrations as low as 1:1 to as high as 10³:1; in wastewater at various seasons the ratio was 10⁵:1; in trickling filter effluents in winter it was 10⁴:1; in spring 10⁵:1, in summer and fall 10⁴:1, in oxidation pond effluents in winter 10³:1; in spring 10⁴:1; and in summer and fall 10³:1. Out of three epidemics in small communities caused by failure of water supply, coliphages were found to be positive. At the same time only two samples of human enteric viruses were positive (the third was contaminated with yeasts).Chlorination experiments using the experimental oxidation pond showed that f2 was most resistant, MS₂ was very resistant, and coliphages were more resistant than attenuated Polio I virus. Experiments with the oxidation pond effluents showed that coliphages were at least as or even more resistant to chlorine than human enteric viruses.     

Ultrasmall Oxygen‐Deficient Bimetallic Oxide MnWOX Nanoparticles for Depletion of Endogenous GSH and Enhanced Sonodynamic Cancer Therapy

Sonodynamic therapy (SDT) triggered by ultrasound (US) has attracted increasing attention owing to its abilities to overcome critical limitations including low tissue‐penetration depth and phototoxicity in photodynamic therapy. Herein, the design of a new type of sonosensitizer is revealed, namely, ultrasmall oxygen‐deficient bimetallic oxide MnWO_X nanoparticles, for multimodal imaging‐guided enhanced SDT against cancer. As‐made MnWO_X nanoparticles with poly(ethylene glycol) (PEG) modification show high physiological stability and biocompatibility. Interestingly, such MnWO_X‐PEG nanoparticles exhibit highly efficient US‐triggered production of ¹O₂ and ?OH, higher than that of previously reported sonosensitizers (e.g., protoporphyrin IX and titanium dioxide), because the oxygen‐deficient structure of MnWO_X serves as an electron trap site to prevent electron–hole recombination. The glutathione depletion capability of MnWO_X‐PEG can also further favor SDT‐triggered cancer cell killing. With efficient tumor homing as illustrated by computer tomography and magnetic resonance imaging, MnWO_X‐PEG enables effective destruction of mouse tumors under US stimulation. After accomplishing its therapeutic functions, MnWO_X‐PEG can be metabolized by the mouse body without any long‐term toxicity. Herein, a new type of sono‐sensitizing agent with high SDT efficacy, multimodal imaging functions, and rapid clearance is presented, an agent which is promising for noninvasive SDT cancer treatment.     

Effluent treatment and algae recovery by ozone-induced flotation

Separation of algae from oxidation pond effluents was tested in a bench scale flotation column using ozone-enriched oxygen. Experimental results indicated that the process could produce a clear, colorless liquid, over 98% removal of suspended solids, and up to three orders of magnitude reduction in fecal coliforms. Ozone dosage ranged from 15 to 50 mgl⁻¹. The collapsed froth thickens to produce a pure algal mass of up to 8.5% solids. It was hypothesized and supported by experimental results that ozone reaction with algal cells results in the formation of a hydrophobic surface amenable to separation by rising bubbles. The high quality products, both liquid and solid, make the combination of stabilization ponds with ozone flotation very attractive for wastewater treatment under certain conditions.     

Lagooned, secondary effluents as water source for extended agricultural purposes

Chlorination of trickling filter effluents at 40 mg l⁻¹ chlorine for 4 h and 20 mg l⁻¹ for 4 and 6 h showed very limited coliform survival. The number of viruses decreased from a few hundred in 100 ml before chlorination to 0 after chlorination. A 70,000 m³ pond (4 m deep) was used for holding non-chlorinated secondary effluents for 73 days. Bacterial and viral counts were performed every few days. In addition BOD, TC, pH and solar radiation were monitored. After this, the water was pumped out and chlorinated in a pipeline with 8 or 20 mg l⁻¹ chlorine. After chlorination the coliform count was reduced by from 3 to 5 orders of magnitude. After storage for 43 days the non-chlorinated secondary effluents viral count was nil. After chlorination these effluents were also virus-free.

In the second experiment, secondary effluents chlorinated with 20 mg l⁻¹ chlorine with a contact period of 2 h. They were then introduced to the pond. No viruses were found in the incoming water, neither during holding nor after the second chlorination, Coliform regrowth was very slow because of the temperature of the water was only 18–20°C. Identification of the M. Endo membrane filter grown isolated colonies proved that E. coli I disappeared, and all the coliforms were of non-fecal origin or that other growths were non-coliform organisms growing on the MF.

The third experiment was a repetition of the first, in spring, after the temperatures rose. The results confirmed the findings in the first experiment. Therefore, it is thought that 70 days holding of wastewater would permit its extensive agricultural use. For safety, the addition of 20 mg l⁻¹ chlorine to effluents and a short storage could be adequate from a public health point of view.