Rapidly Deployable Algae Cleaning System for Applications in Freshwater Reservoirs and Water Bodies

Occurrence of large-scale harmful algal blooms (HABs) in our reservoirs and water bodies threaten both quality of our drinking water and economy of aquaculture immensely. Hence, rapid removal of HAB biomass during and after a bloom is crucial in protecting the quality of our drinking water and preserve our water resources. We reported here a rapidly deployable algae cleaning system based on a high-capacity high-throughput (HCHT) spiral blade continuous centrifuge connected with inlet and effluent water tanks and a series of feed-in and feed-out pumps as well as piping, all fitted into a standard 20 feet metal shipping container. The system separates algal biomass from algae-laden water with a maximum flow rate of 4000 L/h and a centrifugal force of 4500× g. Cells collected by the system are still intact due to the low centrifugal force used. We showed that after HCHT centrifugation, cellular contents of HAB biomass were not found in the effluent water, and hence, could be discharged directly back to the water body. Furthermore, the addition of flocculants and chemicals prior to the separation process is not required. The system could operate continuously with proper programmed procedures. Taken overall, this system offered a much better alternative than the traditional flocculation- and sonication-based methods of HAB removal in a freshwater environment. This deployable system is the first of its kind being built and had been field-tested successfully.

Water Quality Indicator Interval Prediction in Wastewater Treatment Process Based on the Improved BES-LSSVM Algorithm

This paper proposes a novel interval prediction method for effluent water quality indicators (including biochemical oxygen demand (BOD) and ammonia nitrogen (NH3-N)), which are key performance indices in the water quality monitoring and control of a wastewater treatment plant. Firstly, the effluent data regarding BOD/NH3-N and their necessary auxiliary variables are collected. After some basic data pre-processing techniques, the key indicators with high correlation degrees of BOD and NH3-N are analyzed and selected based on a gray correlation analysis algorithm. Next, an improved IBES-LSSVM algorithm is designed to predict the BOD/NH3-N effluent data of a wastewater treatment plant. This algorithm relies on an improved bald eagle search (IBES) optimization algorithm that is used to find the optimal parameters of least squares support vector machine (LSSVM). Then, an interval estimation method is used to analyze the uncertainty of the optimized LSSVM model. Finally, the experimental results demonstrate that the proposed approach can obtain high prediction accuracy, with reduced computational time and an easy calculation process, in predicting effluent water quality parameters compared with other existing algorithms.

An investigation into the role of treatment performance and soil characteristics of soil-based wastewater treatment systems

Soil-based onsite wastewater treatment systems (OWTS) are becoming more important for the treatment and disposal of wastewater in areas that have not central wastewater collection and treatment systems. However, there are concerns that OWTS may have adverse effects on public health and environment. The purpose of this study is to treat wastewater with using natural soil column in order to evaluate treatment system performance. Wastewater was applied to two different natural soils at different flow rates of 9, 18 and 36 L/day. The treatment performances of wastewater and geotechnical properties of the natural soils were examined. As a result of this study, the percentage of COD and SS removal in wastewater after soil column filtration were range from 36.2% to 80.5% and 84.4% to 97.9% respectively. pH values of wastewater after the filtration were measured between 7.75 and 8.12. TP and TN removal rates were found in the range of 23.9–76.8% and 12.4–83.0%, respectively. The column effluent water were classified as both ‘high hardness class’ in terms of hardness and ‘polluted water’ in terms of conductivity. Column effluent water were found in ‘low, medium, and high hazard’ classes in terms of SAR. Whereas the PL values of the natural soils were found to increase by up to 4.8% in filtration area, specific gravity decrease nearly 1.1%. The values of LL, PI, maximum dry density, optimum water content, and permeability were changed depending on the soil type. The UCS of the natural soils after wastewater filtration decreased by about 5.9%. It was concluded that natural soils have positive effects on treatment of wastewater in short time.

The prevalence of SARS-CoV-2 in sewage waste water: A review

Since one and half years, the pandemic of SARS-CoV-2 virus (disease caused is Covid-19) has ruined the entire humanity in unimaginable ways, whether it is economy or unemployment or children mental health disorder or large number of deaths. There is no country in the world which is not affected by this virus. In some countries, this pandemic is coming in the form of outbreak such as first wave of pandemic then after some gap period, second wave of pandemic. In country like India, the second wave of corona pandemic has crippled the economy, public health safety and at the same time put a big question on the health infrastructure of entire nation whether it is availability of oxygen cylinders, or testing facility, hospital bed or ventilators. The actual number of patients who can get affected had not been estimated correctly. This poses more problems due to asymptomatic nature of the expression of COVID-19 on individual basis. Tragically, for developing countries like India with high population density, the situation has been more complex. Additionally, more amount of waste from the Covid affected population goes to effluent water, waste water coming out of residential area, hospitals, isolation centres and so on. In this review article, we have focused on presence of corona virus and infection transmission through effluent water in country like India with huge number of population and also provide further scope in research to inform future studies.

Biodegradation of P-nitro phenol using a novel bacterium Achromobacter denitrifacians isolated from industrial effluent water

In the present investigation, Achromobacter denitrifacians was isolated from industrial wastewater and used in the degradation of para nitro-phenol. Experiments were made as a function of different carbon sources, organic and inorganic nitrogen sources and metal ions to analyse the removal efficiency of para nitro-phenol present in the industrial wastewater sources. Observations revealed that the rate of phenol biodegradation was significantly affected by pH, temperature of incubation, glucose, peptone and metal ion concentration. The optimal conditions for phenol removal was found to be pH of 7.5, temperature, 35 °C and 0.25 gL−1 supplemented glucose level, 0.25 gL−1 supplemented peptone level, and 0.01 gL−1 zinc ion. The key importance of the present study is the utilization of native bacterial strain isolated from the industrial effluent water itself having an impending role in the bioremediation process of phenol.