Comparison of Pistia Stratiotes and Lemna Minor Plants Potentials in Bioremediation of Domestic Wastewater

Phytoremediation is an eco-friendly and cost-effective biotechnological method of wastewater treatment that involves the use of plants. In this research work, the potentials of Pistia stratiotes and Lemna minor aquatic plants in treatment of wastewater was examined. The two plants were cultivated in the wastewater sample for a period of 10 days. Water quality parameters (turbidity, chemical oxygen demand (COD), phosphate, ammoniacal nitrogen and nitrate) tests was subjected on the untreated (influent) and treated water (effluent) samples at a detention time of 24 hours. The outcome of the analysis demonstrates that P. stratiotes effluent achieved a reduction efficiency of up to 91.9%, 68%, 79.6%, and 71% for turbidity, phosphate, ammoniacal nitrogen and nitrate, respectively. Whereas for L. minor treated water samples, the highest reduction efficiency for turbidity, COD, phosphate, ammoniacal nitrogen and nitrate was found to be 87.2%, 46%, 48.7%, 83% and 56%, respectively. Hence, the overall outcome obtained indicate that P. stratiotes performed better in improving the quality of domestic wastewater compared to L. minor plants.

INDUCTIVE PARAMETRIC EDDY-CURRENT TRANSDUCER (IPEP) FOR MEASURING ELECTRICAL AND TEMPERATURE PARAMETERS OF WASTEWATER FROM BREWING PRODUCTION

The possibility of using the theory of operation of a differential inductive parametric eddy-current transducer (IPET) for measuring the electrical and temperature parameters of a sample of acidic and alkaline wastewater is investigated. The need for the development of new informative methods for measuring the physicochemical parameters of wastewater is proved, in the realization of which a promising method of purification is selected. On the basis of a differential scheme for switching on two parametric converters: with exemplary purified water and a converter in which a test tube with a sample of waste water from a brewing production is placed, a differential informative method for measuring the electrical and temperature parameters of the liquid under study is proposed, which is based on the analysis of the components of the difference signal of phase shift angles measured electrical components of the switching circuit signals. The basic relationships that describe the operation of the IPET with the sample of the controlled liquid are given. The scheme of switching on differential IPET with a liquid sample, which is placed in a glass test tube, is considered; the differential scheme provides for heating the sample during measurements to simulate the production conditions of brewing production. Universal transformation functions are given that relate the components of the IPET signals with the specific electrical conductivity χt.s. and the temperature t of the wastewater sample from brewing production, that is, the dependence of the phase difference signal Δj on the generalized parameter A and the dependence of the absolute increment in the specific electrical conductivity Δχ on the temperature t of the wastewater sample, in the investigated temperature range.

Decolorization of industrial wastewater using electrochemical peroxidation process

In this study, decolorization of wastewater samples taken from the paper industry is investigated using electrochemical peroxidation process. The electrochemical peroxidation process is a part of electrochemical advanced oxidation processes, which is based on the Fenton’s chemical reaction, provided by addition of external H2O2 into reaction cell. In this study, iron is used as anode and graphite as cathode put at the fixed distance of 30 mm in a glass reaction cell. The cell was filled with the solution containing wastewater and sodium chloride as the supporting electrolyte. Factors of the process such as pH, current intensity, hydrogen peroxide concentration, and time of treatment were studied. The results illustrate that all these parameters affect efficiencies of dye removal and chemical oxygen demand (COD) reducing. The maximal removal of wastewater contaminants was achieved under acid (pH 3) condition, with the applied current of 1 A, and hydrogen peroxide concentration of 0.033 M. At these conditions, decolorization process efficiency reached 100 and 83 % of COD removal after 40 minutes of wastewater sample treatment. In addition, the electrical energy consumption for wastewater treatment by electrochemical peroxidation is calculated, showing increase as the current intensity of treatment process was increased. The obtained results suggest that electrochemical peroxidation process can be used for removing dye compounds and chemical oxygen demand (COD) from industrial wastewaters with high removal efficiency.

Rapid and direct method to extract SARS-CoV-2 RNA from municipal wastewater using the Chemagic™ 360 12-rod head platform v1

Wastewater based epidemiology (WBE) has emerged as a strategy to identify, locate, predict, and manage outbreaks of COVID-19, as an early warning signal to public health authorities of an expected surge in cases that may overwhelm local and global health care resources.. The WBE process is based on assaying municipal wastewater for molecular markers of the SARS-CoV-2 virus. The standard process for sampling municipal wastewater is time-consuming and requires the handling of large quantities of wastewater, which negatively affects throughput and timely reporting, and can increase safety risks. We report on a rapid and direct mostly automated method to assay multiple sub-samples of a bulk wastewater sample using a 75 minute run on the Chemagic™ 360 12 rod head platform. Including a preceding setup and incubation step, twelve 10 ml samples can be processed to purified RNA in 2.5 hrs. Up to 10 ml of wastewater from 12 different collection sites can be processed in 2.5 hrs.

Enhanced Solar Photocatalytic Reduction of Cr(VI) Using a (ZnO/CuO) Nanocomposite Grafted onto a Polyester Membrane for Wastewater Treatment

Among chemical water pollutants, Cr(VI) is a highly toxic heavy metal; solar photocatalysis is a cost-effective method to reduce Cr(VI) to innocuous Cr(III). In this research work, an efficient and economically feasible ZnO/CuO nanocomposite was grafted onto the polyester fabric ZnO/CuO/PF through the SILAR method. Characterization by SEM, EDX, XRD, and DRS confirmed the successful grafting of highly crystalline, solar active nanoflakes of ZnO/CuO nanocomposite onto the polyester fabric. The grafting of the ZnO/CuO nanocomposite was confirmed by FTIR analysis of the ZnO/CuO/PF membrane. A solar photocatalytic reduction reaction of Cr(VI) was carried out by ZnO/CuO/PF under natural sunlight (solar flux 5–6 kW h/m2). The response surface methodology was employed to determine the interactive effect of three reaction variables: initial concentration of Cr(VI), pH, and solar irradiation time. According to UV/Vis spectrophotometry, 97% of chromium was removed from wastewater in acidic conditions after four hours of sunlight irradiation. ZnO/CuO/PF demonstrated reusability for 11 batches of wastewater under natural sunlight. Evaluation of Cr(VI) reduction was also executed by complexation of Cr(VI) and Cr(III) with 1, 5-diphenylcarbazide. The total percentage removal of Cr after solar photocatalysis was carried out by AAS of the wastewater sample. The ZnO/CuO/PF enhanced the reduction of Cr(VI) metal from wastewater remarkably.

Activated carbon assisted electrocoagulation process for treating biotreated palm oil mill effluent

Electrocoagulation (EC) is a sustainable wastewater treatment alternative that is widely studied because of its environmentally friendly nature, versatility, and simplicity in setup and operation. However, EC alone cannot treat wastewater up to reusable standards and requires integration with other processes, mostly by adding highly hazardous oxidants. This work aims to investigate the combination of powdered activated carbon (AC) with biotreated palm oil mill effluent (BPOME) as wastewater sample, in the EC reactor, and to optimize its concentration for maximum pollutant removal efficiency. Ranging from 0.5-1.5 wt. % concentration of AC mixed with EC reactor, EC was carried out with its critical parameters set to a current of 1.75 A (i.e., 160 mA/cm2 current density) and initial pH 6 and 10 mm interelectrode distance with aluminum electrodes. The EC treated wastewater was sampled from 5 minutes to 60 minutes and the parameters monitored were total suspended solids (TSS), turbidity, color and chemical oxygen demand (COD). Turbidity, TSS and color were removed nearly to completion within 5 to 15 minutes of EC, whereas maximum COD removal was determined to be 84.6 % with 1 wt. % powdered AC combined with EC, which is an increase of about 14.6% compared to EC with no AC addition. The optimum concentration of AC for maximum removal efficiency on BPOME was 1 wt. % (2 g per 200 ml). Addition of AC in EC resulted in a faster pollutant removal rate, with enhanced process efficiency.

Potential Use of Untreated Wastewater for Assessing COVID-19 Trends in Southern Italy

As a complement to clinical disease surveillance, the monitoring of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) in wastewater can be used as an early warning system for impending epidemics. This study investigated the dynamics of SARS-CoV-2 in untreated wastewater with respect to the trend of coronavirus disease 2019 (COVID-19) prevalence in Southern Italy. A total of 210 wastewater samples were collected between May and November 2020 from 15 Apulian wastewater treatment plants (WWTP). The samples were concentrated in accordance with the standard of World Health Organization (WHO, Geneva, Switzerland) procedure for Poliovirus sewage surveillance, and molecular analysis was undertaken with real-time reverse-transcription quantitative PCR (RT-(q) PCR). Viral ribonucleic acid (RNA) was found in 12.4% (26/210) of the samples. The virus concentration in the positive samples ranged from 8.8 × 102 to 6.5 × 104 genome copies/L. The receiver operating characteristic (ROC) curve modeling showed that at least 11 cases/100,000 inhabitants would occur after a wastewater sample was found to be positive for SARS-CoV-2 (sensitivity = 80%, specificity = 80.9%). To our knowledge, this is the first study in Italy that has applied wastewater-based epidemiology to predict COVID-19 prevalence. Further studies regarding methods that include all variables (meteorological phenomena, characteristics of the WWTP, etc.) affecting this type of wastewater surveillance data would be useful to improve data interpretation.

Efficacy of SARS-CoV-2 wastewater surveillance for detection of COVID-19 at a residential private college

Many colleges and universities utilized wastewater surveillance testing for SARS-CoV-2 RNA as a tool to help monitor and mitigate the COVID-19 pandemic on campuses across the United States during the 2020-2021 academic year. We sought to assess the efficacy of one such program by analyzing wastewater RNA load data in relation to SARS-CoV-2 cases identified through individual surveillance testing. Almost 80% of the cases on campus were associated with positive wastewater tests, resulting in an overall positive predictive value of ~79% (Chi square 48.1, Df = 1, p < 0.001). However, half of the positive wastewater samples occurred in the two weeks following the return of a student to the residence hall following isolation, and therefore were not useful in predicting new infections. When these samples were excluded, the positive predictive value of a positive wastewater sample was ~54%. Overall, we conclude that the continued shedding of viral RNA by patients past the time of potential transmission confounds the identification of new cases using wastewater surveillance, and decreases its effectiveness in managing SARS-CoV-2 infections on a residential college campus.

New Insight on Antibiotic Resistance and Virulence of Escherichia coli from Municipal and Animal Wastewater

Antibiotic resistance of the indicator microorganism Escherichia coli was investigated in isolates from samples collected during the course of one year from two wastewater treatment plants treating municipal and animal wastes in Slovakia, respectively. The genes of antibiotic resistance and virulence factors in selected resistant E. coli isolates were described. A high percentage of the isolates from municipal and animal wastewater were resistant to ampicillin, streptomycin, tetracycline, ceftiofur, ceftriaxone, and enrofloxacin. In the selected E. coli isolates, we detected the following phenotypes: ESBL (20.4% in animal wastewater; 7.7% in municipal wastewater), multidrug-resistant (17% of animal and 32% of municipal isolates), high resistance to quinolones (25% of animal and 48% of municipal samples), and CTX-M (7.9% of animal and 17.3% of municipal isolates). We confirmed an integro-mediated antibiotic resistance in 13 E. coli strains from municipal and animal wastewater samples, of which the Tn3 gene and virulence genes cvaC, iutA, iss, ibeA, kps, and papC were detected in six isolates. One of the strains of pathogenic E. coli from the animal wastewater contained genes ibeA with papC, iss, kpsII, Int1, Tn3, and Cit. In addition, one blaIMP gene was found in the municipal wastewater sample. This emphasises the importance of using the appropriate treatment methods to reduce the counts of antibiotic-resistant microorganisms in wastewater effluent.