The prevalence of cyanobacteria is increasing in freshwaters due to climate change, eutrophication, and their ability to adapt and thrive in changing environmental conditions. In response to various environmental pressures, they produce toxins known as cyanotoxins, which impair water quality significantly. Prolonged human exposure to cyanotoxins, such as microcystins, cylindrospermopsin, saxitoxins, and anatoxin through drinking water can cause severe health effects. Conventional water treatment processes are not effective in removing these cyanotoxins in water and advanced water treatment processes are often used instead. Among the advanced water treatment methods, adsorption is advantageous compared to other methods because of its affordability and design simplicity for cyanotoxins removal. This article provides a current review of recent developments in cyanotoxin removal using both conventional and modified adsorbents. Given the different cyanotoxins removal capacities and cost of conventional and modified adsorbents, a future outlook, as well as suggestions are provided to achieve optimal cyanotoxin removal through adsorption.

COVID-19 was not taken seriously by many of us until the wave hit our countries and impacted daily life routines and travel plans, similar to our responses to climate change. COVID-19 led to a decrease of anthropogenic activities in Turkey, largely due to lockdown. Changes in the air quality index (AQI) were assessed before and during coronavirus. In this study, the authors investigated the changes of AQI for 2.5 µm particulate matter (PM 2.5), a primary air pollutant, as well as ozone, a secondary air pollutant, in Turkey during December 2019, April 2020, and May 2020. Overall, the PM 2.5 index improved by 34.5% by the end of April 2020. However, the ozone index increased from 16.8 to 28.8 by the end of April. The increase in ozone is attributed to the reduction of PM levels, which increased sunlight penetration. Before COVID-19, the AQI for Turkey was categorized as unhealthy for sensitive groups (PM 2.5 = 103); however, during the pandemic, AQI fell to lower boundaries of the moderate category by May 2020 (PM 2.5 = 56.9). Changes in municipal wastewater were also assessed. Municipal wastewater quality and hospital waste generation did not change during the pandemic in Turkey. Therefore, we should not expect COVID-19 risks in treatment plant effluents. This study gives confidence to regulators that when strict measures are implemented, air quality can improve.

No abstract

No abstract

No abstract