Membrane aerated biofilm reactor system driven by pure oxygen for wastewater treatment.

Pure oxygen is proposed for wastewater treatment due to its advantages over conventional air aeration. This study investigates a Pure Oxygen-based Membrane Aerated Biofilm Reactor (PO-MABR) for the first time under various operating conditions. The PO-MABR employs a gas-permeable membrane for direct diffusion of low-pressurized pure oxygen to the biofilm, ensuring exceptional carbon and nitrogen removal. The effectiveness of PO-MABR was investigated by varying operational conditions, including temperature, carbon-to-nitrogen ratio, gas pressure, and flow rate. Results indicate superior performance, with a 97% chemical oxygen demand removal and 19% higher total nitrogen removal than Air-Ventilated MABR (A-MABR) due to thicker biofilm and unique microbial structures in PO-MABR. Also, PO-MABR demonstrated resilience to low temperatures and effectively treated both high and low-strength wastewater. The findings emphasize the efficiency of PO-MABR in wastewater treatment, advocating for its adoption due to superior carbon and nitrogen removal across diverse operational conditions.

Microalgae-based wastewater treatment: Mechanisms, challenges, recent advances, and future prospects.

The rapid expansion of both the global economy and the human population has led to a shortage of water resources suitable for direct human consumption. As a result, water remediation will inexorably become the primary focus on a global scale. Microalgae can be grown in various types of wastewaters (WW). They have a high potential to remove contaminants from the effluents of industries and urban areas. This review focuses on recent advances on WW remediation through microalgae cultivation. Attention has already been paid to microalgae-based wastewater treatment (WWT) due to its low energy requirements, the strong ability of microalgae to thrive under diverse environmental conditions, and the potential to transform WW nutrients into high-value compounds. It turned out that microalgae-based WWT is an economical and sustainable solution. Moreover, different types of toxins are removed by microalgae through biosorption, bioaccumulation, and biodegradation processes. Examples are toxins from agricultural runoffs and textile and pharmaceutical industrial effluents. Microalgae have the potential to mitigate carbon dioxide and make use of the micronutrients that are present in the effluents. This review paper highlights the application of microalgae in WW remediation and the remediation of diverse types of pollutants commonly present in WW through different mechanisms, simultaneous resource recovery, and efficient microalgae-based co-culturing systems along with bottlenecks and prospects.

High-strength wastewater treatment using microbial biofilm reactor: a critical review.

Biofilm reactors retain microbial cells in the form of biofilm which is attached to free moving or fixed carrying materials, thus providing a high active biomass concentration and automatic liquid and solid separation. Nowadays, microbial biofilm reactors have been widely used in high-strength wastewater treatment where very high pollutant removal efficiency is required, which usually requires excessive space and aeration energy for conventional activated sludge-based treatment. This paper provides an overview of microbial biofilm reactors developed over the last half-century, including moving bed biofilm reactor (MBBR), trickling filter (TF) reactor, rotating biological contactor (RBC), membrane biofilm reactor (MBfR), passive aeration simultaneous nitrification and denitrification (PASND) biofilm reactor, for their applications in high-strength wastewater treatment of not only removing carbon, nitrogen, sulphur but also a variety of oxidized contaminants including perchlorate and bromate. Despite the advance of biofilm reactor that exhibits high resistance to excessive pollutants loading, its drawbacks both from engineering and microbiological point of view are reviewed. The future prospects of biofilm reactor are also discussed in this review paper.

Does Adding Fluoxetine to Combined Oral Contraceptives Containing Drospirenone Improve the Management of Severe Premenstrual Syndrome? A 6-Month Randomized Double-Blind Placebo-Controlled Three-Arm Trial.

To compare efficacy of combined use of fluoxetine and combined oral contraceptives (COC) versus COC alone in treating severe premenstrual syndrome (PMS), a randomized double-blind placebo-controlled three-arm trial was conducted at Cairo and Beni-Suef University Hospitals. PMS was diagnosed prospectively using the Daily Record of Severity of Problems (DRSP). Three hundred women with severe PMS were randomly divided into three equal groups. Group 1 received oral fluoxetine 20 mg daily in addition to COC containing drospirenone daily for 21 days. Group 2 received COC containing drospirenone daily for 21 days in addition to daily oral placebo. Group 3 received placebo similar to COC and oral placebo similar to fluoxetine. Drug duration was 6 months, and women kept daily records of their symptoms using the Daily Record of Severity of Problems (DSRP) form. The main outcome was the number of women with improved PMS in the final cycle of treatment. Women with improved PMS decreased progressively between groups during last treatment month (65% vs. 50% and 2% respectively; p < 0.0001). Combined use of fluoxetine and COC containing drospirenone is superior to COC in severe PMS.

A parametric study of alum recovery from water treatment sludge.

Alum recovery from water treatment sludge is a promising technique applied to decrease usage of fresh coagulants in the water treatment industry. In addition, alum recovery reduces sludge volume for easy handling. The undertaken work investigated the parametric conditions for alum recovery procedure by acidification. The results show that alum recovery reaches up to 69.03%, and the reduction of sludge volume reaches its highest level at 90%. Moreover, results of the parametric investigation reveal that the mixing time of 60 minutes and mixing intensity of 150 rpm are the optimum conditions of mixing for alum recovery from water treatment sludge. The optimum pH level is 1.50 for alum recovery as indicated by maximum aluminum releasing, maximum reduction of sludge volume, and reasonable dosages of added sulfuric acid.