Microalgae as Bioabsorbents for Treating Mixture of Electroplating and Sewage Effluent

The effectiveness of copper and nickel uptake by microalgae grown in the mixture of electroplating effluent and sewage was studied. The results showed that a high percentage of copper removal (68.1%-88.2%) was achieved by Chlorellapyrenoidosa (strain No. 26) reared in the mixture of 90% electroplating effluent and 10% raw sewage during the first 3 days despite the fact that cell growth was inhibited. Similar results were also obtained by using Chlorella HKBC-C3, another species collected from one of the heavy metal polluted sites in Hong Kong, isolated and cultured in the Biology Department. There was no significant difference (P>0.05) in the removal of copper and nickel from the effluent between these 2 algal species. However, it was noted that removal of nickel from the mixture by the two species were comparatively lower (<20%) than the removal of copper (>68%).

Treated wastewater irrigation effect on soil,crop and environment:Wastewater recycling in the loess area of China

A study was carded out at the Loess Plateau in Dongzhi, China, to test the feasibility of using secondary treatment sewage effluent and to determine whether the water quality would then meet the recommended irrigation norm. Seven crops, including celery, wheat, maize, millet, apples, rapeseed and yellow beans, were tested in the study. Physical and chemical properties of the soil, crop yield and quality and leachate at different soil depths were measured. In most cases, the quality of the crops that made use of treated sewage was not distinctively different from those that did not use treated sewage. However, yields for the former were much higher than they were for the latter. Leachates at different soil depths were analyzed and the results did not show alarming levels of constituents. For a period of approximately 14 months, the treated sewage irrigation had no significant effect on the loess soil and no cases of illness resulting from contact with the treated sewage were reported. With treated sewage irrigation, a slight increase in the organic content of the soil was observed.

Neural stem cell-based in vitro bioassay for the assessment of neurotoxic potential of water samples

Intensive agriculture activities,industrialization and growing numbers of wastewater treatment plants along river banks collectively contribute to the elevated levels of neurotoxic pollutants in natural water reservoirs across Europe.We established an in vitro bioassay based upon neural stem cells isolated from the subventricular zone of the postnatal mouse to evaluate the neurotoxic potential of raw wastewater,treated sewage effluent,groundwater and drinking water.The toxic potential of water samples was evaluated employing viability,proliferation,differentiation and migration assays.We found that raw wastewater could reduce the viability and proliferation of neural stem cells,and decreased the neuronal and astrocyte differentiation,neuronal neurite growth,astrocyte growth and cell migration.Treated sewage water also showed inhibitory effects on cell proliferation and migration.Our results indicated that relatively high concentrations of nitrogenous substances,pesticides,mercuric compounds,bisphenol-A,and phthalates,along with some other pollutants in raw wastewater and treated sewage water,might be the reason for the neuroinhibitory effects of these water samples.Our model successfully predicted the neurotoxicity of water samples collected from different sources and also revealed that the incomplete removal of contaminants from wastewater can be problematic for the developing nervous system.The presented data also provides strong evidence that more effective treatments should be used to minimize the contamination of water before release into major water bodies which may be considered as water reservoirs for human usage in the future.