Optimal design of an electrochemical reactor for blackwater treatment.

Electrolysis of blackwater for disinfection and nutrient removal is a portable and scalable technology that can lessen the need for cities to construct large-scale wastewater treatment infrastructure and enable the safe onsite reuse of blackwater. Several systems for treating wastewater from single toilets are described in the literature, but there are few examples of systems designed to use electrolysis to treat blackwater from nearby toilets, which is a situation more common in densely packed urban living environments. In order to scale a single toilet electrolysis system to one that could service multiple toilets, computational fluid dynamic analysis was used to optimize the electrochemical reactor design, and laboratory and field-testing were used to confirm results. Design efforts included optimization of the reactor shape and mixing to improve treatment efficiency, as well as automated cleaning and salt injection to reduce maintenance and service requirements. PRACTITIONER POINTS: Design of a reverse polarity mechanism to enable in situ electrode cleaning and improve long-term electrode performance. Optimization of a hopper design and drainpipe location to collect and remove flaking precipitates and mitigate maintenance issues. Design of an automated salt injection system to guarantee sufficient chloride levels for producing adequate chlorine residuals for consistent disinfection.

Resolving the relative contributions of cistern and pour flushing to toilet water usage: Measurements from urban test sites in India.

A challenge in water reuse for toilet flushing in India and other Asian countries derives from pour flushing practices. It is a common assumption that the amount of pour flushed water used for personal cleansing is small in comparison to the cistern flush volume, however there is a knowledge gap regarding the actual contribution of each water source to the blackwater amount. In this study, digital water meters were used to measure the fraction of water from personal wash tap relative to cistern water that is used for toilet flushing. High temporal resolution measurements were carried in three different urban sites in the city of Coimbatore in the southern Indian state of Tamil Nadu where onsite sanitation treatment prototypes that may provide reclaimed water for cistern flushing are being tested. Data collected over periods of up to 2 months show that the contribution of the cistern flush to the total blackwater volume is low (14-40%). These data highlight an important factor to inform interventions designed around water reuse for flushing in world geographies where personal toilet cleansing by water is the common practice.

Impact of learning curve on the perioperative outcomes following robot-assisted partial nephrectomy for renal tumors.

INTRODUCTION: Robot-assisted partial nephrectomy (RAPN) is an established, minimally invasive technique to treat patients with renal masses. The aim of this study was to assess the learning curve (LC) of RAPN, evaluate its impact on perioperative outcomes following RAPN and to study the role of surgeon experience in achieving "trifecta" outcomes following RAPN. METHODS: We prospectively analyzed the clinical and pathological outcomes of 108 consecutive patients who underwent RAPN for renal tumors from January 2012 to December 2016 by a laparoscopy trained surgeon with no prior robotic experience. We used warm ischemia time (WIT) <20 min, operative time <120 min, and blood loss <100 ml as endpoints for plotting the LCs. Trifecta was analyzed in relation to our LC. RESULTS: Surgeon experience was found to correlate with WIT, operative time, and blood loss. Overall 18.5% of patients developed complications. Complication rate reduced with increasing surgeon experience. LC was 44 cases for WIT ≤20 min, 44 cases for operative time <120 min, and 54 cases for blood loss <100 ml. Trifecta outcome was achieved in 67.6% patients overall and was found to correlate with increasing surgeon experience. Improvement in trifecta outcomes continued to occur beyond the LC. CONCLUSIONS: RAPN is a viable option for nephron-sparing surgery in patients with renal carcinoma. For a surgeon trained in laparoscopy, acceptable perioperative outcomes following RAPN can be achieved after an LC of about 44 cases. Increasing surgeon experience was associated with improved "trifecta" achievement following RAPN.

Parapelvic solitary neurofibroma of the kidney.

A middle-aged man presented with intermittent gross haematuria and dull aching left flank pain for 1 month. He was a chronic smoker for 15 years. Contrast-enhanced CT scan of the abdomen detected a 4.5×3.0×2.5 cm, heterogeneous and poorly contrast-enhancing mass in the left renal sinus and upper ureteric region causing narrowing of the pelviureteric junction and upper ureter. Considering it to be a transitional cell carcinoma of upper urinary tract, the patient underwent laparoscopic radical nephroureterectomy. Histopathology revealed the mass to be a neurofibroma in the renal sinus extending around the upper ureter.