An Enhanced System with Macrophytes and Polyurethane Sponge as an Eco-Technology for Restoring Eutrophic Water: A Pilot Test

Nitrogen removal by a strengthened comprehensive floating bed with embedded pellets made by a newly isolated Pseudomonas sp. Y1

A newly heterotrophic nitrification aerobic denitrification(HN-AD) bacterium Pseudomonas sp. Y1 with highly nitrogen removal ability was isolated from the activated sludge, TN removal rate of which was 99.73%. In this study, two types of different ecology floating bed systems were designed to achieve efficient nitrogen removal in the urban eutrophic landscape water body, one is the comprehensive ecological floating bed(CEFB) system with only Lythrum salicari and the other is the strengthened comprehensive ecological floating bed (SCEFB) system with both Lythrum and embedded pellets made by Y1. The TN removal rates of the CEFB system were 33.82%, 83.84% and 88.91% at 8±1℃, 15±1℃ and 25±1℃, respectively, while the TN removal rates of the SCEFB system increased by nearly 40%, 16% and 11% at the same environment, respectively. The result shows that the SCEFB system can purify the simulated water from surface water body class V to class IV. Thus it has a broad application prospect in the urban eutrophic landscape water body.

The potential of white-rot fungi for algal control: Mechanisms, Strategies, and Challenges

As human society and industrialization have progressed, harmful algal blooms have contributed to global ecological pollution which makes the development of a novel and effective algal control strategy imminent. This is because existing physical and chemical methods for dealing with the problem have issues like cost and secondary pollution. Benefiting from their environmentally friendly and biocompatible properties, white-rot fungi (WRF) have been studied to control algal growth. WRF control algae by using algae for carbon or nitrogen, antagonism, and enhancing allelopathies. It can be better applied to practice by immobilization. This paper reviews the mechanism for WRF control of algae growth and its practical application. It demonstrates the limitations of WRF controlling algae growth and aids the further study of biological methods to regulate eutrophic water in algae growth research. In addition, it provides theoretical support for the fungi controlling algae growth.

Effect of the Matrix Dam in the Paddy Field Drainage Ditch on Water Purification Based on the Physical Model Test

(1) Setting a matrix dam in the paddy field drainage ditch has been recognized as an effective method to lower the velocity of water discharged from a paddy field in the drainage ditch, which can improve the purification efficiency of the drainage ditch for nitrogen and phosphorus pollutants, but the specific placement and thickness of the matrix dam have not been supported due to the insufficient research results. (2) Three thicknesses of the matrix dam were set in three locations of the physical model of the drainage ditch. By measuring the flow rate and water level in different sections, the optimal layout location and thickness of the matrix dam were determined. (3) When the matrix dam was located in section 1-1, the flow rate from sections A-A to C1-C1 was reduced by 0.159 m/s; when the matrix dam was located in section 2-2, the flow rate was reduced by 0.331 m/s; when the matrix dam was located in section 3-3, the flow rate was reduced by 0.360 m/s. (4) We concluded that the optimal design position of the matrix dam was section 3-3, 9.2 m from the entrance of the water flume, and the optimal design thickness was 0.3 m.

Recent developments and applications of floating treatment wetlands for treating different source waters: a review

Most water bodies around the world suffer from pollution to varying degrees. Floating treatment wetlands (FTWs) are a simple and efficient ecological treatment technology and have been widely studied and applied as a sustainable solution for different source waters. Based on the analysis of abundant literature in the last ten years, this paper systematically reviews the history and the latest development of FTWs. Meanwhile, the treatment performance and pollutant removal mechanisms of FTWs on the natural water, stormwater, domestic wastewater, industrial wastewater, and agricultural runoff are analyzed. In particular, very interesting information is provided, such as water depth, water surface coverage, the ratio of dissolved to total phosphorous (DRP/TP), the ratio of nitrogen to phosphorous (N/P), BOD/COD ratio, and its effects on the efficiency and removal mechanisms of FTWs. This information will provide useful references and guidance for optimizing the design of FTW and pollutant treatment efficiency of different source waters. This paper also provides an objective review of the limitations of FTWs. Subsequently, the enhancements of FTW technology which are recognized to be effective, including aeration, adding functional fillers or obligate degrading bacteria, and construction of hybrid FTWs, are summarized and recommendations are made for further research.