PROMISING METHODS FOR BIOLOGICAL REMOVAL OF PHOSPHATES FROM WASTEWATER

The article compares the removal of phosphates from wastewater by promising biological methods, namely biotechnologies based on the use of phosphate-accumulating organisms. The microbial community under study gives great hopes for further fundamental studies of the metabolism of phosphate-accumulating organisms, and for improving biotechnologies for purifying wastewater from phosphorus.

On the issue of the feasibility of using modern technologies for biological phosphorus removal in low-capacity wastewater treatment plants

The article discusses the basic principles of wastewater treatment from biogenic elements, provides the necessary conditions for the biological removal of phosphorus compounds. The technology of pre-fermentation of the sediment of primary sedimentation tanks, options for its design, the main parameters of the process are described. Specific aspects of the operation of low-capacity wastewater treatment facilities are indicated and the expediency of using the technology of biological phosphorus removal in them is considered.

Removal of nutrients from aquaculture residual water: A review

Aquaculture plays an important role in providing protein-rich foods, meeting the growing demand for fish. However, aquaculture is a potentially polluting activity, especially with regard to water pollution, due to the improper disposal of wastewater from the production process. Aquaculture wastewater is rich in nutrients (ammonia, nitrate, nitrite and phosphorus) and organic matter, and is commonly discharged into the environment without proper treatment. This can cause a series of environmental impacts and aggravate the current water crisis. Due to the importance and need to reduce environmental impacts, plan the use of water resources and achieve an efficient and sustainable production process, many researchers have focused their studies on effluent treatment techniques designed to remove these nutrients. This article therefore presents an updated review of the main physicochemical and biological techniques used in the removal of nutrients, which can mitigate environmental problems arising from aquaculture activities and contribute to the sustainability of the activity. Keywords: biological removal, nitrogen compounds, sustainable activity.

Wild Type and Variants of Sars-Cov-2 in Parisian Sewage: Dynamics in Raw Water and Fate in Wastewater Treatment Plants

The presence of SARS-CoV-2 RNA has been extensively reported at the influent of wastewater treatment plants (WWTPs) worldwide and its monitoring has been proposed as a potential surveillance tool to early alert of epidemic outbreaks. However, the fate of the SARS-CoV-2 RNA in the treatment process of WWTP has not been widely studied yet; therefore in this study, we aimed to evaluate the efficiency of treatment processes in reducing SARS-CoV-2 RNA levels in wastewater. The treatment process of three WWTPs of the Parisian area in France were monitored on six different weeks over a period of two months (from April 14th to June 9th 2021). SARS-CoV-2 RNA copies were detected using digital polymerase chain reaction (dPCR). Investigation on the presence of variants of concern (Del69-70E484 and L452R) was also performed. Additionally, SARS-CoV-2 RNA loads in the WWTPs influents were expressed as the viral charge per population equivalent and showed a good correlation with French public health indicators (incidence rate). SARS-CoV-2 RNA loads were notably reduced along the water treatment lines of the three WWTPs studied (2.5-3.4 log). Finally, very low SARS-CoV-2 RNA loads were detected in effluents (non-detected in over half of the samples) which indicated that the potential health risk of the release of wastewater effluents to the environment is probably insignificant, in the case of WWTPs enabling an efficient biological removal of nitrogen.

Abundance and Potential Biological Removal of Common Dolphins Subject to Fishery Impacts in South Australian Waters

Conservation management of wildlife species should be underpinned by knowledge of their distribution and abundance, as well as impacts of human activities on their populations and habitats. Common dolphins (Delphinus delphis) are subject to incidental capture in a range of Australia’s commercial fisheries including gill netting, purse seining and mid-water trawling. The impact these fishery interactions have on common dolphin populations is uncertain, as estimates of abundance are lacking, particularly for the segments of the populations at risk of bycatch and in greater need of protection. Here we used double-observer platform aerial surveys and mark-recapture distance sampling methods to estimate the abundance of common dolphins in 2011 over an area of 42,438 km2 in central South Australia, where incidental mortality of common dolphins due to fisheries bycatch is the highest. We also used the potential biological removal (PBR) method to estimate sustainable levels of human-caused mortality for this segment of the population. The estimated abundance of common dolphins was 21,733 (CV = 0.25; 95% CI = 13,809–34,203) in austral summer/autumn and 26,504 in winter/spring (CV = 0.19; 95% CI = 19,488–36,046). Annual PBR estimates, assuming a conservative maximum population growth rate of Rmax = 0.02 and a recovery factor of Fr = 0.5 for species of unknown conservation status, ranged from 189 (summer/autumn) to 239 dolphins (winter/spring), and from 378 (summer/autumn) to 478 dolphins (winter/spring) with an Rmax = 0.04. Our results indicate that common dolphins are an abundant dolphin species in waters over the central South Australian continental shelf (up to 100 m deep). Based on the 2011 abundance estimates of this species, the highest estimated bycatch of common dolphins (423 mortalities in 2004/05) in the southern Australian region exceeded the precautionary PBR estimates for this population segment. Recent bycatch levels appear to be below PBR estimates, but low observer coverage and underreporting of dolphin mortalities by fishers means that estimates of dolphin bycatch rates are not robust. The effects of cumulative human impacts on common dolphins are not well understood, and thus we recommend a precautionary management approach to manage common dolphin bycatch based on local abundance estimates.