Investigation and Evaluation of Algae Removal Technologies Applied in Domestic Rivers and Lakes

Abstract

Commercial 28 algae removal technologies that have been applied in domestic rivers and lakes with green tide were investigated, analyzed and classified. The classification of algae removal technologies was based on the three criteria (i.e., principle, flow rate of water body, and application period). Also, algae removal technologies were evaluated in terms of cost effectiveness, field applicability, effect durability, and eco friendliness. From the analysis results, technologies using physical, chemical, biological, and convergent controls were 32.2%, 25%, 21.4%, and 21.4%, respectively. The 75% of technologies have been applied to stagnant water body (≤0.2 m/s). Also, algae harvesting ship with dissolved air flotation, conveyor belt and filtration processes and natural floating coagulant were found to have better field applicability, compared to other technologies. However, proper algae removal technology in specific rivers and lakes should be chosen after the evaluation of long-term pilot scale field test. Also, development of energy and resource recovery technologies from algae biomass is warranted.

Analysis of Growth Inhibition for Microcystis aeruginosa with Periodic Ultrasonic Irradiations

“…[10][11][12][13][14] 유해남조류의 저감을 위해 흔히 사용되고 있는 조류 저감기 술들은 적용 원리에 따라 물리적(physical), 화학적(chemical), 생물학적(biological) 그리고 이들의 복합적(combined) 사용에 의한 기술로 크게 구분된다. [15][16][17][18] 최근 연구되고 있는 다양한 HABs 저감 공법 중 물리적 공법인 초음파(ultrasonic)를 이용 한 처리기술은 초음파의 공동현상(cavitation)으로 조류 세포 내 기낭을 파괴하여 부력조절 능력을 상실시켜 조류를 호소 바닥으로 가라앉게 하고, 광합성을 차단하여 조류의 성장을 억제하는 기술이다. [19][20][21][22][23][24][25] 이러한 초음파 처리 기술은 남조류의 세포분열을 억제하여 조류의 대발생을 예방하고 M. aeruginosa 로부터 생성되는 강한 독성을 지닌 microcystin-LR 분해에 효 과가 있다고 보고되며, 수체 내 화학약품의 주입 없이 조류 저감이 가능하여 수생태계의 위해성이 낮은 기술이다.…”

Oscillation Flow Dam Operation Method for Algal Bloom Mitigation

“…Flushing flow is an algal control method that increases flow velocity to influence river stability and control algae. For example, Byeon et al [11] determined that algae prefer stagnant lakes, reservoirs, and rivers with flow velocities of 0.2 m/s or less, where the residence time of the water is relatively long. Under these conditions, the nutrients required for algal growth can be transferred easily, thus leading to the overgrowth and accumulation of algae.…”

“…The use of artificial wetlands after sewage treatment plant or freshwater shellfish circumfusion in rivers are examples of biological methods [8][9][10]. Finally, combined methods combine physical, chemical, or biological methods [11].…”

“…One of these conditions is the duration of effectiveness. Most green algae control technologies have exhibited short-term algae inhibition effects of less than two weeks, but algae bloom typically occurs throughout the summer and fall seasons in South Korea [11]. Therefore, treatment must be applied repeatedly [12], limited the practical effect on algae bloom in rivers, dams, and reservoirs [13,14].…”

The effect of the combined system of Hydrodynamic Cavitation, Ozone, and Hydrogen Peroxide on the removal of Chlorophyll a and Organic substances in the raw water

“…It is a crucial parameter reflecting the nutrient status of water bodies and can be used to estimate phytoplankton biomass and productivity. Due to their small size, high mobility, low density, and negatively charged surface, algal cells in many existing water treatment plants cannot be removed or treated (Jia et al 2018;Yang et al 2021;Byeon et al 2016 andGallardo et al 2019). Algae from water sources are controlled using various physical, chemical, and biological techniques.…”