Comparison of phosphorus removal efficiency of conventional activated sludge system and sequencing batch reactors in a wastewater treatment plant

The aim of this study was to evaluate the effectiveness application of sequencing batch reactors (SBRs) for phosphorus removal compared to the conventional activated sludge (CAS) treatment system. The results showed that the removal efficiency of phosphorus reached about 99% at wastewater treatment plant with CAS system. At the same time, the maximum phosphorus removal efficiency can be achieved to 88% if the SBRs system operating parameters are optimized. Finally, this study demonstrated that even if granules are not fully developed, the SBR system is working with a good efficiency

Management of wastewater from landfill of inorganic fiberglass

ArticleSustainability is one of the key factors in smart environment management and include the reduction of environment footprint. The waste and wastewater management plans are aimed on actions to reduce the amount of waste and environmental pollution. This includes collection of waste, logistics, storage, processing or valorisation and also treatment. The aim of this research was to evaluate environmental pollution risk and to demonstrate one of the wastewater management schemes to reduce the pollution level. Evaluation of the better management scheme was performed in one of the landfills in Latvia, where fiberglass waste and other inorganic waste is stored. Onsite evaluation results demonstrated the need to develop a better wastewater management scheme of inorganic fiberglass landfill. After that, laboratory–scale experiments for conventional coagulation and biodegradation tests have been performed for efficient management

New device for air disinfection with a shielded UV radiation and ozone

Received: February 1st, 2021 ; Accepted: May 2nd, 2021 ; Published: May 7th, 2021 ; Correspondence: [email protected] air disinfection has become particularly relevant recently because of the Covid-19 pandemics. A shielded device for air and surface disinfection with UV radiation and ozone has been developed. It contains 28 low intensity (11 W) UV lamps (254 nm) in a specially designed three-dimensional grid to provide a large flow cross-sectional area and long path for the air particles to be irradiated. The device can be used in medical institutions, veterinary clinics, manufacturing plants, public premises, poultry, and livestock farms. It does not generate air-ions and ozone concentrations do not exceed the allowed 8-hour average values. The large number of UV lamps and powerful fans ensure air disinfection in large rooms in a relatively short time (400 m3 h -1 ). Simultaneously, the floor surface under the appliance is disinfected. Disinfection efficiency tests demonstrated 99.9999% reduction for Escherichia coli, Staphylococcus aureus and Pseudomonas phage Φ6 aerosols within a single transfer through the system (10 seconds of treatment). The housing of the device protects from direct UV radiation; therefore, people can be in the room during the operation of the device

Artificial Recharging of Ground Water Resources Experience in Well Field “Baltezers” (Latvia)

In several well fields in the region Baltezers the Quaternary shallow groundwater with artificial groundwater recharge system is used For Riga city water supply. A Hidrogeological modelling and field investigation was done to asses the risk for groundwater quality and for optimisation of the system of artificial recharge of groundwater resources. Detailed investigations shows, that Steady state HM cannot provide information needed for elaboration of optimal recharge rates and method of controlling them, the transient HM of the Baltezers well fields must be used for those purposes. Artificial recharging of groundwater resources in the Baltezers region does not make risk for groundwater quality to exceed permitted parameters’ values for drinking water, and make substation contribution to protect groundwater quality from possible contamination from new urban territories in NW from the siphon lines in Baltezers region

Escherichia coli and Enterococcus spp. in rainwater tank samples: comparison of culture-based methods and 235 rRNA gene quantitative PCR assays

In this study, culture-based methods and quantitative PCR (qPCR) assays were compared with each other for the measurement of Escherichia coli and Enterococcus spp. in water samples collected from rainwater tanks in Southeast Queensland, Australia. Among the 50 rainwater tank samples tested, 26 (52%) and 46 (92%) samples yielded E. coli numbers as measured by EPA Method 1603 and E. coli 23S rRNA gene qPCR assay, respectively. Similarly, 49 (98%) and 47 (94%) samples yielded Enterococcus spp. numbers as measured by EPA Method 1600 and Enterococcus spp. 23S rRNA gene qPCR assay, respectively. The mean E. coli (2.49 ± 0.85) log and Enterococcus spp. (2.72 ± 0.32) log numbers as measured by qPCR assays were significantly (P < 0001) different than E. coli (0.91 ± 0.80) log and Enterococcus spp. (1.86 ± 0.60) log numbers as measured by culture-based method. Weak but significant correlations were observed between both EPA Method 1603 and the E. coli qPCR assay (r = 0.47, P = 0.0009), and EPA Method 1600 and the Enterococcus spp. qPCR assay (r = 0.42, P = 0.002). Good qualitative agreement was found between the culture-based method and the Enterococcus spp. qPCR assay in terms of detecting fecal pollution in water samples from the studied rainwater tanks. More research studies, however, are needed to shed some light on the discrepancies associated with the culture-based methods and qPCR assays for measuring fecal indicator bacteria