High-pressure batch reverse osmosis (RO) for zero liquid discharge (ZLD) in a Cr(III) electroplating process

A batch RO system was designed and built for high-pressure (120 bar) operation. The system was developed for a ZLD application involving treatment of metal plating wastewater from a Cr(III) electroplating process at a major industrial plant. Hybrid semi-batch/batch operation enabled a compact design to be achieved. To maximize water recovery without exceeding a set peak pressure, a method for controlling the switch point between semi-batch and batch phases was developed. The system was tested with feed representative of rinse water from the electroplating process. A range of feed concentrations (at 10–20× dilution of the plating bath), feed flows (0.21–0.46 m3/h), water fluxes (6–14 LMH) and water recoveries (87–95.7 %) were investigated. The system successfully recovered Cr(III) and restored its concentration to that of the electrolyte bath, thus meeting the requirements for reuse in the electroplating process. Rejection of most species was >99.8 %, sufficient for reuse of the permeate as rinse. However, rejection of boric acid was only 69–80 % such that a second RO pass may be needed to remove boric acid. Specific Energy Consumption was <2.25 kWh per m3 of treated rinse water, representing a 50-fold saving compared to the current method of treatment and disposal at the industrial plant

Early failure detection for bearings in electrical environments

Bearings in electrical environments have been the subject of many publications. These bearings tend to be the victims of early failure in many different applications. In some cases, insulating or grounding the bearings can prevent the failure, but in other cases, especially in combination with the failure mechanism of white etching cracks, no definitive final answer has yet been proposed. In this work, a test-rig that can create white etching cracks in combination with an electric load is used to test a newly developed electrostatic sensor and to further investigate the root causes of the mechanisms of white etching crack formation for early failure detection

Hyposalivation and xerostomia among Parkinson's disease patients and its impact on quality of life

ObjectiveParkinson's disease (PD) adversely affects oral health (OH). However, the informative value of xerostomia compared to objective parameters and its impact on quality of life (QoL) are still unclear. This study aimed to explore whether xerostomia correlates with hyposalivation and to define its impact on OH-related QoL. Materials and MethodsWhole stimulated saliva (WSS) was collected from 30 patients with PD and 30 matched healthy controls. Objective parameters (community periodontal index of treatment needs, plaque/gingivitis index, mucosa situation and cheilitis angularis) and questionnaires (German Oral Health Impact Profile [OHIPG]-14, visual analogue scale [VAS], xerostomia [yes/no] and the Unified Parkinson's Disease Rating Scale-II) were assessed. ResultsEighty-seven per cent of patients with PD showed hyposalivation vs 50% of controls (P=0.001); 50% of patients with PD reported xerostomia, and none of controls (P<0.001). The OHIPG-14 was impaired in patients with PD compared to controls (P<0.001), PD patients with xerostomia reported mean VAS values of 4.1 (s.d.: 2.2). WSS did not correlate with VAS values. ConclusionsHalf of the patients with PD reported xerostomia and underestimated their xerostomic status, with higher probability than healthy controls. WSS did not reflect the grade of xerostomia. Patients with PD suffered from impaired OH-related QoL. Dental teams should not overlook these oral health risks