Comparison of the efficiencies of attached- versus suspended-growth SBR systems in the treatment of recycled paper mill wastewater

Application of Multifunctional Intelligent Suspension Treatment Beds in Nursing Care of Patients with Extensive Burns

The nursing care of patients with extensive burns by using multifunctional intelligent suspension treatment beds was studied. 40 patients, including 30 males and 10 females, with extensive burns were nursed using multifunctional intelligent suspension treatment beds. First of all, the patients were given psychological care, which was patiently explained, so that they can overcome their fears and be treated with peace of mind. Second, the room temperature and bed temperature were closely monitored. Finally, special attention was paid to the adjustment of rehydration volume, regular detection of plasma electrolytes, prevention of electrolyte disorder, and dehydration. Besides, disinfection and isolation should be performed when using. The results showed that 4 cases (20%) were positive in group A and 8 cases (40%) were positive in group B on the 10th day after injury (X²=4.005), and the incidence of wound infection in group A was significantly lower than that in group B. The use of suspension beds in patients with extensive burns makes them safe and comfortable, and the whole body wound scabs healed faster, as well as the infection was minimized. A suspended bed is especially suitable for the clinical treatment of patients with extensive burns. The advantages of suspended bed can be fully realized by summarizing clinical experience.

Coupling of thermophilic biofilm-based systems and ozonation for enhanced organics removal from high-temperature pulping wastewater: Performance, microbial communities, and pollutant transformations

This study focused on the establishment of thermophilic biofilm-based systems (TBSs) coupled with ozonation for treatment of high-temperature pulping wastewater. The effects of the inoculum, sludge growth mode, and temperature were investigated. These factors played roles in the organics removal performance and microbial communities of pulping wastewater treatment systems. At 50 °C, the TBS inoculated with optimal inoculum achieved 59.12% and 37.96% reductions in COD and chromaticity, which were superior to the reductions achieved by other systems. In this TBS, thermophilic lignocellulolytic microorganisms (Chloroflexus, Meiothermus, norank_f_Caldilineaceae, and Roseiflexus) and carbohydrate-fermenting bacteria (norank_f_Anaerolineaceae) were predominant. Their relative abundances were 25.55% and 10.42%, respectively. For enhanced removal of COD and chromaticity, an integrated system consisting of a primary TBS, ozonation, and a secondary TBS was proposed. The total COD and chromaticity removal efficiencies increased to 90.48% and 87.89%, respectively. BOD₅/COD increased from 0.20 to 0.40, and shifts of lignin-like and humic acid-like substances were observed during ozonation with the primary TBS effluent.

Enhanced biodegradation of phenol in a novel cyclic activated sludge integrated with a rotating bed bioreactor in anoxic and peroxidase-mediated conditions

Cyclic activated sludge integrated with a rotating bed bioreactor (CASIR) was used for phenol biodegradation. The effects of phenol loading rate, mixed liquor suspended solids (MLSS) concentration, media filling ratio, hydraulic retention time (HRT) and salinity were investigated for phenol degradation and COD removal. In the second phase of the study, the microbial content of the bioreactor was induced by hydrogen peroxide injection for in situ generation of peroxidase. For investigating the above-mentioned parameters, the bioreactor was operated for 535 days and residual phenol, nitrate and COD were measured daily. The variation of the dehydrogenase activity and peroxidase activity of suspended biomass and attached film were also monitored during the bioreactor operation. Complete degradation of phenol at the loading rate of 667 g m⁻³ d⁻¹ was achieved in anoxic conditions. Addition of media to the bioreactor to form active attached biofilm led to the increase in tolerance of the bioreactor on organic loading shocks. It was found that increasing the salinity of the wastewater did not affect the performance of the bioreactor. Investigating dehydrogenase activity proved that the attached biofilm was more involved in phenol degradation, compared with the suspended biomass. However, after switching to peroxidase-mediated conditions, the organic loading tolerance of the bioreactor considerably increased and complete degradation of phenol at the loading rate of 2000 g m⁻³ d⁻¹ was reached. After adaptation of the microorganisms for hydrogen peroxide, the peroxidase activity of 290 U g_biomass⁻¹ was observed in the bioreactor. Accordingly, the H₂O₂-induced microbial cells in cyclic activated sludge could be considered as a promising technique for enzymatic degradation of phenol and corresponding COD.

Cyclic activated sludge integrated with a rotating bed bioreactor (CASIR) was used for phenol biodegradation.