Simultaneous removal of tetracycline and copper ions from wastewater by flow-electrode capacitive deionization.

To effectively solve the problem of tetracycline (TC) and Cu contamination in wastewater, this study innovatively proposed a low-energy flow-electrode capacitive deionization (FCDI) technology to simultaneously remove TC and Cu from wastewater. The removal efficiencies of TC and Cu using FCDI was investigated under various voltages, electrode flow rates, influent flow rates, and electrode liquid concentrations. The results showed that the removal efficiency of TC and Cu was 60.

Managing stability of aerobic granules by coordinating diameter and denitrification.

Aerobic Granular Sludge (AGS) technology is a promising solution for wastewater treatment due to its structure and high biomass retention capacity. However, the stability of AGS is still a challenge for widespread use. This study investigated the relationships among granule stability, granule diameter, biomass retention capacity, and denitrification efficiency.

Hierarchically porous biochar derived from aerobic granular sludge for high-performance membrane capacitive deionization.

Membrane capacitive deionization (MCDI) is a cost-effective desalination technique known for its low energy consumption. The performance of MCDI cells relies on the properties of electrode materials. Activated carbon is the most widely used electrode material.

Roles of high/low nucleic acid bacteria in flocs and probing their dynamic migrations with respirogram.

Bacterial migration is crucial for the stability of activated sludge but rarely reported. The static distribution was explored by changes in bacteria concentration with extracellular polymeric substances (EPS) extractions. Next, denitrification and aeration were conducted as normal running conditions for examining the bacterial migration between floc-attached and dispersed growth.

Hierarchical stringent response behaviors of activated sludge system to stressed conditions.

The stringent response of activated sludge systems to either stressed or harmful environments is important for the stable operation of activated sludge, which is examined by taking copper ion (Cu) as a stress model in this study. When weak stress was employed (Cu ≤ 2.5 mg/L), the N-acyl-homoserine lactones (AHLs) of C6-, C8-, and C10-HSL increased by 30 %, 13 %, and 127 %, respectively, while the redox sensor green (RSG) intensity decreased by 28 %.

A novel approach to estimate and control denitrification performance in activated sludge systems with respirogram technology.

Respirogram technology has been widely applied for aerobic process, however, the response of respirogram to anoxic denitrification is still unclear. To reveal such response may help to design a new method for the evaluation of the performance of denitrification. The size distribution of flocs measured at different denitrification moments demonstrated a clear expansion of flocs triggered by denitrification, during which higher specific endogenous and quasi-endogenous respiration rates (SOUR and SOUR) were also observed.

A new approach to evaluate and improve the stability of aerobic sludge systems based on maintenance coefficient.

Stability is a key issue of wastewater treatment plants using either aerobic granular (AGS) or conventional activated sludge (CAS). The two forms of aerobic sludge were cultivated under different conditions to study the main factors affecting their stability. It was found that maintenance coefficient (m) describing the fraction of non-growth energy of granules increased significantly when the system became more stable during processes with the enhancement of granulation and the periodic short-term shock load.

Simultaneous evaluation of bioactivity and settleability of activated sludge using fractal dimension as an intermediate variable.

Bioactivity and settleability of activated sludge are essential for the operation of activated sludge systems in wastewater treatment. In this work, the fractal dimension of sludge image is proposed as a tool to evaluate these two factors. The specific endogenous respiration rate (SOUR) and the specific quasi-endogenous respiration rate (SOUR) are found to be more dependent on the 3D structure of sludge than the specific total respiration rate (SOUR).

Tuning of activated sludge in winter based on respirogram profiles under standard and site temperatures.

Respirograms of activated sludge OUR and OUR were measured under site (T) and standard (20°C) temperatures, respectively, and the predicted standard temperature respirogram OUR was also calculated using the Arrhenius equation. These respirogram profiles reveal more information than effluent quality. A decrease of OUR is a critical alarm signal for the loss of pollutant removal capacity, and a sudden increase of the predicted value OUR is an alarm signal for the unrecoverable deterioration of biomass.

Difference of respiration-based approaches for quantifying heterotrophic biomass in activated sludge of biological wastewater treatment plants.

Estimation of heterotrophic biomass concentration in activated sludge is essential to the design, operation and management of activated sludge process for wastewater treatment plants (WWTPs), and many methods have been developed for such a purpose. In this study, three respiration-based methods: the Exponential-growth-rate-based method (Exp-M), the Maximum-respiration-rate-based method (Max-M) and the Endogenous-respiration-rate-based method (End-M), which are frequently used for determining kinetic parameters in activated sludge models, were comparatively examined using experimental results from both full-scale municipal WWTPs and laboratory-scale reactors. Our study revealed the pros and cons of each method, which is valuable for method selection in different applications.

Impact of Obesity on Perioperative Outcomes of Retroperitoneal Laparoscopic Adrenalectomy.

Introduction: Obesity is usually considered a risk factor for postoperative complications; however, previous studies conclude contradictory results in retroperitoneal laparoscopic adrenalectomy (LA). We aim to evaluate the impact of obesity on the perioperative outcomes of LA.

Methods: A retrospective cohort study from a single center including 353 patients from 2011 to 2013 was conducted.