Fate of antibiotic resistant genes in wastewater environments and treatment strategies - A review.

High adsorption capacities of crystal violet dye by low-cost activated carbon prepared from Moroccan Moringa oleifera wastes: Characterization, adsorption and mechanism study

Phosphorus is one of the pollutant's parameters causing environmental pollution, known as eutrophication. Coagulation-flocculation is a widely known technology to treat phosphorus-containing wastewater; however, using metal-based coagulants raises some environmental concerns related to their toxicity. Natural coagulants offer an option to treat wastewater containing phosphorus with comparable performance to chemical coagulants. The utilization of natural coagulants removed phosphorus (as phosphate) from wastewater with an efficiency of up to 99.6 %. Removal of phosphate from wastewater by natural coagulant was highly correlated with the charge neutralization mechanism. The use of phosphate-rich resultant sludge as soil conditioner/fertilizer is made possible by using natural coagulant compared to metal-based coagulant due to its lower metal content and toxicity to plants and aquatic organisms. The combination of treatment with other technologies, such as the filtration unit, showed significant improvement in phosphorus removal, which also alleviated the load of the next unit, including ultraviolet disinfection, whose performance might be affected by high solid content. Despite its promising performance, the selection of raw materials, extraction, and purification of natural coagulants become the major challenge in the further application of this option. This review article discusses the aforementioned topics and highlights future research directions of developing simpler extraction/purification processes of natural coagulants and analysis of natural coagulants' performance in treating different speciation of phosphorus in wastewater to enhance this particular knowledge. 

A review on revolutionary technique for phosphate removal in wastewater using green coagulant

Water treatment is the primary consideration before utilizing water for different purposes. Surface water is highly vulnerable to pollution, either due to natural or anthropogenic processes. The main targets of this study were to investigate surface water treatment using Moringa Oleifera (MO), the electrocoagulation process (EC), and the Moringa Oleifera assisted electrocoagulation process (MOAEC). The Moringa Oleifera, EC process, and Moringa Oleifera-assisted EC process are effective mechanisms for the removal of COD (Chemical Oxygen Demand), BOD (Biological Oxygen Demand), TDS (Total Dissolved Solids), phosphate, TSS (Total Suspended Solids), and color from surface water. Different operating parameters such as pH (5–11), the dosage of coagulant (0.2–0.5 g), contact time or reaction time (20–50 minutes), current (0.2–0.5 A), and settling time (5–20 minutes) were considered. The maximum removal efficiency using Moringa Oleifera and the EC process was COD (85.48%), BOD (78.50%), TDS (84.5%), phosphate (95.70%), TSS (93.90%), color (94.50%), and COD (90.50%), BOD (87%), TDS (97.50%), phosphate (89.10%), TSS (95.80%), and color (96.15%), respectively. Similarly, with the application of MOAEC, 91.47%, 89.35%, 97.0%, 90.20%, 9.10%, and 95.70% of COD, BOD, TDS, phosphate, TSS, and color were removed, respectively. The EC process and MOAEC were more effective in the removal of COD, BOD, TDS, TSS, and color than using MO. More phosphate was removed using MO than the EC process and MOAEC. Additionally, the effects of different operating parameters were studied on the removal efficiency.

/pdf/water-treatment-using-natural-coagulant-and-3gmdz5bq.pdf

Water Treatment Using Natural Coagulant and Electrocoagulation Process: A Comparison Study

Moringa oleifera (MO), also known as drumstick tree, has gained worldwide attention among researchers and policy makers, for showing its remarkable potential in environmental management. Recently, MO seed or press cake (a by-product of oil extraction industry) powder has also emerged as an alternative and promising coagulant for environmental remediation. In this view, attempts have been made in this study to evaluate the efficacy of MO seed and press cake powder (MSP & PCP) for the treatment of municipal wastewater. Both MSP and PCP are characterized by using swelling ratio, scanning and transmission electron microscopy analysis. The effect of various operational parameters such as coagulation–flocculation pH (2–10), coagulant dosage (0.1–1 g L−1), and sedimentation time (0–180 min), etc., is investigated to understand the potential of MSP and PCP. At optimized operational conditions, sedimentation kinetics is also performed suggesting that the treatment process is being governed by the second-order kinetic model. The chemical and biological oxygen demand removals at optimized conditions are observed as follows: ≈38 and ≈73% for MSP and ≈47 and ≈85% for PCP. Overall, the results of the present study elucidated that PCP can be employed as a promising alternative of MSP for municipal wastewater with improved treatment efficiencies. 

Million Ebba Bote

Papers

Wastewater treatment using a natural coagulant (Moringa oleifera seeds): optimization through response surface methodology