Prediction and Countermeasures for Reuse and Reclamation of Urban Sewage in Ningxia

A Logistic equation gray prediction model was established for prediction of reuse and reclamation rate of urban sewage in Ningxia.Based on the data of reuse and reclamation of urban sewage in Ningxia in 2006-2013,it analyzed and predicted the development trend of reuse and reclamation of urban sewage in the whole region of Ningxia. The prediction results indicate that: according to the current development trend,the reuse and reclamation rate of the whole region of Ningxia has become close to saturation,the development space is limited,there is a huge gap with the planned objectives,thus it is required to actively adjust the development strategies. On this basis,the main limiting factors affecting the reuse and reclamation of urban sewage in Ningxia were determined by analytic hierarchy process( AHP) method,in order to provide a reference for the rapid development of reuse and reclamation of urban sewage in Ningxia.

Probing the Affinity of Coronavirus with Contact Surfaces in Simulated Body Fluids

Transmission of viral pathogens has raised serious public health concerns,but the affinity and strength of viruses adhering to hightouch surfaces are not clear.We systematically investigated the propensities of a coronavirus,Murine hepatitis virus A59(MHV),adhering onto and releasing from four representative contact surfaces,silica,stainless steel,cellulose,and polystyrene,in simulated saliva and urine using quartz crystal microbalance with dissipation monitoring(QCM-D).We also quantified the interactions between MHV and contact surfaces using atomic force microscopy(AFM).Both initial adhesion rates and saturated adhesion mass of MHV were higher in urine buffer than in saliva buffer,which is attributed to the higher repulsions between the virus and surfaces in the presence of mucin.The maximum adhesion mass of MHV follows the order of stainless steel>silica>cellulose≈polystyrene in both urine and saliva buffers.Stainless steel and silica are surfaces with likely higher risks of virus contamination due to their highest maximum adhesion mass in both urine and saliva buffers and lower virus release percentages upon water rinse.The results of this study will provide insights into risk assessment and control of pathogens associated with contact surfaces.