Micro-scale observations of the structure of aerobic microbial granules used for the treatment of nutrient-rich industrial wastewater

The structure and function of aerobic microbial granules from a lab-scale sequencing batch reactor treating nutrient-rich abattoir wastewater were investigated. These wastewater-fed granules were examined using a wide range of micro-scale techniques including light microscopy, scanning and transmission electron microscopy, fluorescent in situ hybridisation (FISH) combined with confocal laser scanning microscopy and oxygen and pH microsensors, in conjunction with a range of measurements in the bulk liquid phase. Interesting structural features were observed in these granules that have not been reported in synthetic-fed granules. The complex nature of abattoir wastewater was suggested to be responsible for accelerating the breaking process of large mature granules due to a rapid clogging of the granules pores and channels and for the very diverse microbial community observed displaying specific spatial distribution throughout the granules. More importantly, the dissolution at lower pH of mineral complexes associated to the granule matrix of extracellular polymeric substances might have caused the structural damages observed on the granules even though some pH buffer capacity was observed inside these granules. Ciliate protozoa were found to be very abundant on the surface of these wastewater-fed granules, which could potentially assist with reducing the high levels of suspended solids usually present in the aerobic granular sludge effluent. All these observations provide support to future studies on aerobic granular sludge treating real wastewater especially with regard to the granule structure and the mechanisms involved in their formation

Management of the helmeted athlete with suspected cervical spine injury

Improper handling of an unstable neck injury may result in iatrogenic neurologic injury. A review of published evidence on cervical management in the helmeted athlete with a suspected spinal injury is discussed. The approach to the neck-injured helmeted athlete and the algorithms for on-field and emergency department evaluations are reviewed. The characteristics of the fitted football helmet allow safe access for airway management, and helmets and shoulder pads should not be initially removed unless absolutely necessary. Prehospital and emergency personnel should be trained in the indications for removal and in proper helmet, shoulder pad, and facemask removal techniques. If required, both helmet and shoulder pads should be removed simultaneously. Radiographs with equipment in place may be inadequate, and the value of computed tomography and magnetic resonance imaging in these helmeted patients has been studied. If adequate films cannot be obtained with equipment in place, helmet and shoulder pads may need to be removed before radiographic clearance. A plan should be formulated to prepare for such unexpected clinical scenarios as cervical spine injuries, and skills should be practiced. Airway and cervical spine management in these helmeted athletes is an area of ongoing research