Liter Of Wastewater Research Articles

Microfibers release during washing and, removal by tamarind fruit shell carbon filters: Subsequent utilization in crystal violet dye removal from water

The release of synthetic microfibers (MFs) into the environment has been correlated to the laundering of clothes due to mechanical and chemical stresses preferably during hand washing based on conventional brushing practices. At this juncture, the present research explores the possible release of MFs in water by brush washing experiments on nylon and polyester clothes using four different quality brushes. The ejection of MFs from fabric as a function of brushing time (1 – 4h), brushing area, quality of brushes and cloth type was investigated. The lengths of MFs were dominated mostly in the range of 100 – 200 μm and 200 – 400 μm along with the presence of microplastics (MPs) as threads, tubules and granules. The fabric materials were characterized using Fourier – Transform Infrared (FTIR) and Scanning Electron Microscope (SEM) with Elemental Dispersive Spectroscopy (EDS) techniques before and after the brush washing experiments. The pyrolysis Gas Chromatography – Time of Flight – Mass Spectroscopic (Py – GC-ToF-MS) study was performed to analyse the pyrolyzate products from the extracted MFs and MPs. Furthermore, the study was further extended into the abatement of MFs/MPs in wastewater samples discharged from the brush washing studies using acid washed tamarind fruit carbon (ATFSC) by columnar technique. The total time of 186h at a flow rate of 1.7ml per minute was spent for treating 19L of wastewater samples with 3480 MFs (WW – 1) and 2858 MFs (WW – 2) as a consequence of brush washing experiments. It was apparent from the microscopic examination that the MFs remain undetectable till 12.24litres of wastewater (1 & 2) samples which passed through the column for 120h. The ATFSC (AT) resulting after the filtration followed by thermal treatment was converted as barium alginate/carbon composites. These composites were found efficient in removing 83% of crystal violet from aqueous solution at pH 7.97 for an equilibrium time of 90min. The corresponding adsorption kinetics revealed the compliance of pseudo – second – order model with respect to domination of chemical forces during sorption. The present research not only explores the elimination of MFs/MPs from wastewater but also the possible conversion in the form of carbon composites followed by application in the removal of crystal violet from water.

Combining Activated Carbon Adsorption and CO2 Carbonation to Treat Fly Ash Washing Wastewater and Recover High-Purity Calcium Carbonate

Fly ash washing wastewater was carbonated with carbon dioxide (CO2) to remove calcium (Ca) by forming a calcium carbonate (CaCO3) precipitate. An investigation of the factors affecting carbonation showed that Ca removal was highly dependent on the initial pH of the wastewater. The Ca removal was 10%, 61%, 91% and more than 99% at initial wastewater pH levels of 11.8, 12.0, 12.5 and 13.0, respectively. The optimal conditions for carbonation were initial pH of 13.0, carbonation time of 30 min and CO2 flow rate of 30 mL/min. The Ca concentration in the wastewater decreased to <40 mg/L, while 73 g of CaCO3 precipitate was produced per liter of wastewater. However, heavy metals, specifically Pb and Zn, co-precipitated during carbonation, which resulted in a CaCO3 product that contained as much as 0.61 wt% of Pb and 0.02 wt% of Zn. Activated carbon modified by a quaternary ammonium salt was used to selectively adsorb the Pb and Zn first. The Pb- and Zn-free water was then carbonated. By combining adsorption with carbonation, the Ca concentration in the treated wastewater was decreased to about 28 mg/L, while the Na, Cl and K were retained. The wastewater thus treated was ready for NaCl and KCl recovery. In addition, the precipitate had a Ca content of more than 38 wt% and almost no heavy metals. The average particle size of the precipitate was 47 μm, with a uniform cubic shape. The quality of the precipitate met the requirements for the industrial reuse of CaCO3. In summary, adsorption and carbonation combined were able to remove pollutants from wastewater while recovering useful resources.

Antarctic wastewater: A local source of microplastic pollution

Microplastic (MP) particles can be found all around the planet, even in Antarctica where they can be locally originated or transported by marine currents and winds. In this communication, we identify and report for the first time the contribution of a wastewater treatment plant (WWTP) as a local source of MP particles in the region. The analysis of the entire sample using micro-Raman spectroscopy revealed an MP concentration that ranged from 64 to 159 particles per liter of wastewater. >90 % of the identified particles were smaller than 50 μm. Among those analyzed, microplastics were identified as polyethylene, polypropylene, polyvinyl chloride, polytetrafluoroethylene, polyethylene terephthalate, and polystyrene. These findings demonstrate the need for urgent policies and technologies to mitigate this MP contamination source.

Optimalisasi Produksi Bersih dengan Pendekatan Neraca Air di Pabrik Tahu ABC

Tofu is a food product derived from soybeans. The production process generates waste that can pollute the environment. This study aims to examine clean production methods through direct observation and interviews. The growth of food industry centers, particularly in Wagir, Malang, has intensified competition, often neglecting environmental impacts. Conducted at ABC tofu factory in December 2022, this research investigates the tofu production stages: soaking, washing, grinding, boiling, filtering, coagulating, pressing, molding, and cutting. Notably, ABC factory’s washing process involves flowing water over soybeans soaked for 3 minutes. Water is essential for all stages except molding and is sourced from a well. The factory’s water storage system fills the tank unless manually stopped. At ABC tofu industry, 4350 liters of water are used for 75 kg of soybeans, producing 3813.3 liters of wastewater. Soaking lasts 4-5 hours in a 42 cm diameter and 50 cm height bucket, causing soybeans to swell and soften. Wastewater volume is measured by filtering water from soaked soybeans in a 7-liter bucket; not all soak water is captured during filtration

Evaluation of nitrogen fate from land-application wastewater treatment for cheese making and vegetable processing facilities

Cheese making and vegetable processing are vital industries worldwide, but their operations generate billions of liters of wastewater annually that must be managed in an environmentally safe yet cost-effective manner.

Locational Characteristics and Impact of Attenda Abattoir, Ogbomoso, Nigeria

The study examined the locational characteristics and impact of attenda abattoir, Ogbomoso town, Oyo State, Nigeria. To achieve this, a ring of a 100-meter radius was delineated around the abattoir, and a landuse inventory was done. Thereafter, observation and measurement were done daily in the abattoir for a month, excluding Sundays. To assess the impact of the abattoir, water samples were obtained from Point of Discharge (POD) of wastewater to the stream, 30 meters, 60 meters and 90 meters on the course of the stream. Also, samples were obtained from a well each, found within 30 meters, 60 meters, and 90 meters from the abattoir. The water samples were, among others, tested for pH Conductivity and Lead. Obtained data were subjected to descriptive statistics such as frequency count and percentage. Tables were also used to summarise data. The closest landuse to the abattoir is a 40 km stream with a setback of 2.6 meters. This setback is used as a waste dump. In the abattoir, an average of 19 cows are killed daily. For this operation, an average of 1153.7 litres of wastewater is generated and discharged into the nearby stream. Hence the pH value of the stream is 5.20, 5.35, 5.41 and 5.40 respectively at POD, 30 meters, 60 meters and 90 meters. Also, the concentration of Lead (Fe2+) in water samples is higher than Federal Environmental Protection Agency (FEPA) limits of 0.01mg/l. The study, among others, recommends relocation of abattoir and urban renewal of abattoir area.

Ultrasound-induced PMS activation for acrylonitrile degradation with series LTZ perovskite-like catalysts: Synergistic and mechanistic insight

The degradation of toxic and refractory pollutants requires an efficient, environmentally friendly, and cost-effective treatment process to address the current challenges associated with wastewater. Herein, we present a hybrid system (LaTixZn1−xO3/PMS/US) that utilizes ultrasound irradiation to activate PMS (peroxymonosulfate) for the degradation of acrylonitrile. The system incorporates a series of perovskite-like catalysts LaTixZn1−xO3 (x = 0.2, 0.4, 0.6, 0.8, 1) fabricated using citric sol-gel method. The texture properties, surface morphology and composition of synthesized catalysts were analyzed by TEM, FESEM/EDS, FTIR, XRD and XPS. Furthermore, influences of operation parameters such as catalyst dose, PMS dose, pH, and US power, co-existing anions were investigated along with PMS utilization efficacy and its consumption rate. Under the optimal conditions, catalyst 0.75LTZ exhibited remarkable catalytic activity for acrylonitrile degradation (98.7%), with synergistic index value (3.363). The trapping experiments and EPR analysis revealed that ROS (SO4•− and •OH) both played a pivotal role in acrylonitrile removal, accordingly a rational mechanism was elucidated. The co-existing ions species HCO3– showed a strong inhibitory effect on acrylonitrile degradation compared to other ionic species (NO3–, Cl–, and SO42–). Based on the GC-MS analysis and existing literature, four possible pathways for the degradation of acrylonitrile were suggested. The treatment process incurred a cost of around 0.081$ per liter of wastewater in the 0.75LTZ/PMS/US system.

Adsorption of Ammonia in Wastewater Using Hyacinth (Eichornia Crassipes) Powder with The Assistance of Bio Balls

<p><span><strong>Abstract.</strong> </span>Water pollution can be caused by the discharge of domestic wastewater containing contaminants. Ammonia is a water pollutant that has a bad impact because it can cause an unpleasant pungent odor and can inhibit or stop the growth of aquatic organisms because it interferes with oxygen binding, changes pH and affects enzymatic reactions and membrane stability in aquatic organisms. This research treats domestic wastewater contaminated with ammonia by means of adsorption using water hyacinth powder. In order to reduce ammonia contaminants in domestic wastewater. This study used a quantitative method which included the acclimatization stage, preliminary test, water hyacinth powder production, adsorption process, ammonia content analysis. The results showed that the use of water hyacinth powder in the most efficient adsorption process was 8 grams of water hyacinth powder and 60 bioballs in 10 liters of wastewater with a decrease in ammonia content of 93.47% for 24 hours. With the bioremediation process ratio, the ammonia content in wastewater can be reduced from 4.810 ppm to 0.314 ppm.</p><p> </p><p><strong>Keywords:</strong></p><p>Adsorption, Domestic Wastewater, Ammonia, Water Hyacinth Powder</p><p><strong><br /></strong></p>

Impact of Urbanization on Rivers, India

Abstract: A Central Pollution Control Board (CPCB) report of 2015 brought out the fact that 61,948 million litres of urban sewage is generated on a daily basis in India. But the cities have an installed sewage treatment capacity of only 38 per cent of this. In reality more than this amount goes untreated into the rivers or water bodies as the treatment capacity of major sewage treatment plants (STPs) in the country is around 66 per cent of the installed capacity as per CPCB findings of 2013. As a result, more than 38,000 million litres of waste water goes into the major rivers, water bodies and even percolates into the ground every day. Accelerated transformation of ‘urban riverfront development’ has been pushed along the riverbanks in the last few decades. The riverfront development has been reduced to just cosmetic ‘river beautification’ and unaccountable money spent to increase its real estate and commercial value. Increasing urbanization in the river basin is followed by a number of serious Physical, Chemical & Environmental impacts on the health of the river basin system. We are in the country where rivers are considered as mother but it is unfortunate to say that Indian rivers are much more polluted in comparison of other rivers of the world. Through this Dissertation it will be tried to understand the major reason citizens are not sensitive towards river and develop understanding how we can rejuvenate our tributary rivers.

Efektivitas Kayu Apu Dan Kangkung Air Untuk Menurunkan Kadar COD, BOD, Dan Amonia Pada Air Limbah Domestik

Domestic wastewater is generated from washing clothes, kitchen and bathroom waste with high organic matter content. The purpose of this study was to determine the effectiveness of Apu (Pistia stratiotes L.) and Water Kangkung (Ipomoea aquatica F.) plants in reducing COD, BOD, and Ammonia levels in domestic wastewater at Cilacap State Polytechnic regarding the quality standard of PP RI No. 22 of 202. The acclimatization process was carried out before processing for 15 days. Wastewater treatment is carried out using 2 container boxes with a volume of 9 liters of waste water. This research was conducted using the phytoremediation method in the form of domestic wastewater with processing for 14 days. Domestic wastewater treatment at Cilacap State Polytechnic based on variations in sampling time on day 0 and day 14, it is known that the performance of Apu wood plants is better than Kangkung in reducing COD, BOD, and Ammonia levels, which are highest on day q4, which is successively to 11.3 mg/L, 3.4 mg/L, and 0.0008 mg/L. The effectiveness of reducing the concentration of COD, BOD, and Ammonia was highest on day 14 in wastewater treatment using Kayu apu plant, namely COD 60.07%; BOD 42.37%; and Ammonia 76.0%. Of the 2 plant variations used, kayu apu was more effective in reducing COD, BOD, and Ammonia.

Utilization of magnetic silica as tofu wastewater treatment absorber (influence of mass and adsorption time)

Wastewater from tofu production generally has many pollutant parameters, such as nitrogen, phosphorus, turbidity, and total suspended solids (TSS). These pollutants can cause a decrease in oxygen levels and pollute water bodies. This study aims to determine changes in pH and removal efficiency of turbidity and TSS in tofu wastewater using the size of 80 mesh magnetic silica. The research used a laboratory-scale batch system with variations in the absorbent mass of 5 g, 7.5 g, and 10 g per 1 liter of tofu wastewater and adsorption times of 15, 30, 45, and 60 minutes. The stirring speed used is 100 rpm, and the operating temperature is adjusted to the laboratory temperature. As a result, the TSS removal has the most effective results of 80%, with 7.5 g of magnetic silica added per liter of wastewater and 45 minutes of adsorption time with a TSS value of 90 mg/L. Meanwhile, the optimum turbidity removal was 82.52% with 7.5 g adsorbent and adsorption time of 15 minutes resulting in a turbidity value of 82.1 NTU. The resulting pH varies in the range of 3.28-4.27, depending on the mass of the adsorbent and the adsorption time.

Using Biological Responses to Monitor Freshwater Post-Spill Conditions over 3years in Blacktail Creek, North Dakota, USA.

A pipeline carrying unconventional oil and gas (OG) wastewater spilled approximately 11 million liters of wastewater into Blacktail Creek, North Dakota, USA. Flow of the mix of stream water and wastewater down the channel resulted in storage of contaminants in the hyporheic zone and along the banks, providing a long-term source of wastewater constituents to the stream. A multi-levelinvestigation was used toassessthe potential effectsofoilandbrine spillson aquatic life. In this study, we used a combination of experiments using a native fishspecies, Fathead Minnow (Pimephalespromelas), field sampling of the microbial community structure, and measures of estrogenicity. The fish investigation included in situ experiments and experiments with collected site water. Estrogenicity was measured in collected site water samples, and microbial community analyses were conducted on collected sediments. Duringthe initial post-spill investigation, February 2015, performingin situ fish bioassays was impossible because of ice conditions. However, microbial community(e.g., the presence ofmembers of theHalomonadaceae, a family that is indicativeofelevated salinity) andestrogenicitydifferences were compared to reference sitesand point toearlybiological effects of the spill. We noted water column effects on in situ fish survival 6months post-spill during June 2015. At that time, total dissolved ammonium (sum of ammonium and ammonia, TAN) was 4.41mgNH4/L with an associated NH3of 1.09mg/L, a concentration greater than the water quality criteria established to protect aquatic life. Biological measurements in the sediment defined early and long-lasting effects ofthe spill on aquatic resources. The microbial community structure wasaffected during all sampling events. Therefore, sediment may act as a sink for constituents spilled and as such provide an indication of continuedand cumulativeeffects post-spill. However, lack of later water column effects may reflect pulse hyporheic flow of ammonia from shallow ground water. Combining fish toxicological, microbial community structureandestrogenicity informationprovides a completeecologicalinvestigation that defines potential influencesof contaminantsatorganismal, population, and community levels. In general, in situ bioassays have implications for the individualsurvivalandchanges at thepopulation level, microbial community structure defines potential changes at the community level, andestrogenicitymeasurements define changes at theindividual andmolecularlevel. By understanding effects at these various levels of biological organization, natural resource managers can interpret how a course of action, especially for remediation/restoration, might affect a larger group of organisms in the system. The current work also reviews potential effects of additional constituents defined during chemistry investigations on aquatic resources.

Hydrogen energy of mining waste waters: Extraction and analysis of solving issues

Billions liters of wastewater are created every day from industrial and domestic locations, and while wastewater is frequently regarded as a concern, it includes the potential to be regarded as a rich supply of energy and materials. The creation of hydrogen gas by electrolysis utilizing a solar system is an alternate method for treating this residual water. Wastewater has four to five times the energy necessary to its treatment and a good source of bio-hydrogen as a feedstock chemical, clean energy vector, and a fuel generally acknowledged to play a part in the energy system's decarburization. The goal of this research was to see how well wastewater might be used to produce anaerobic hydrogen. Synthetic wastewater with high- and ordinary strength organic loadings as real-time residential wastewater with(out) a combination of food waste was examined. Hydrogen generation during sewage sludge and mining residue suspensions coupled was measured using electro dialytic methods at 50 and 100 mA. Hydrogen purity has been reached at 33 % along the electro dialytic treat of sewage sludge. Hydrogen purity reached 71 percent and 34 percent, respectively, while adding sewage sludge or effluent as enhancers in waste solutions. The maximum extraction ratios of phosphorus (71 %) and tungsten (62 %), respectively, were obtained while the technique has been performed to waste suspensions mixed with sewage sludge. This study's findings could be used to develop onsite household energy and wastewater recovery systems.

The more wine, the more gas? Estimation of the bioenergy potential of winery wastewater in Moldova: contributions to sustainable development

Wine is one of the most ancient commodities in the world. The critical residues from the wine industry are grape leaves, stems, grape pomace, grape seeds, yeast lees, tartrate, and wastewater. The indiscriminate disposal of produced wastewater has adverse environmental and health consequences. Nevertheless, winery effluent has substantial prospects as an energy source. Hence, this paper aims to briefly showcase the potential of energy generation from wastewater in the wine industry through anaerobic digestion. From literature and statistical records, in 2018, the cultivation of grapes in Moldova covered about 126,873 ha of land and produced 730,171 t of grapes, with over 24% pressed for wine production. Consequently, the industry released over 6 billion litres of wastewater. Therefore, by anaerobic digestion of this effluent, there is a potential for the wine industry to produce 459,166 MWh of electricity annually to satisfy nearly 287,000 people. This potential represents a very important step towards energy self-sufficiency of the wine industry and a contribution to the sustainable development goals concerning wastewater, energy and sanitation.

Wastewater monitoring of SARS-CoV-2 shows high correlation with COVID-19 case numbers and allowed early detection of the first confirmed B.1.1.529 infection in Switzerland: results of an observational surveillance study.

Wastewater-based epidemiology has contributed significantly to the comprehension of the dynamics of the current COVID-19 pandemic. Its additional value in monitoring SARS-CoV-2 circulation in the population and identifying newly arising variants independently of diagnostic testing is now undisputed. As a proof of concept, we report here correlations between SARS-CoV-2 detection in wastewater and the officially recorded COVID-19 case numbers, as well as the validity of such surveillance to detect emerging variants, exemplified by the detection of the B.1.1.529 variant Omicron in Basel, Switzerland. From July 1 to December 31, 2021, wastewater samples were collected six times a week from the inflow of the local wastewater treatment plant that receives wastewater from the catchment area of the city of Basel, Switzerland, comprising 273,075 inhabitants. The number of SARS-CoV-2 RNA copies was determined by reverse transcriptase-quantitative PCR. Spearman's rank correlation coefficients were calculated to determine correlations with the median seven-day incidence of genome copies per litre of wastewater and official case data. To explore delayed correlation effects between the seven-day median number of genome copies/litre wastewater and the median seven-day incidence of SARS-CoV-2 cases, time-lagged Spearman's rank correlation coefficients were calculated for up to 14 days. RNA extracts from daily wastewater samples were used to genotype circulating SARS-CoV-2 variants by next-generation sequencing. The number of daily cases and the median seven-day incidence of SARS-CoV-2 infections in the catchment area showed a high correlation with SARS-CoV-2 measurements in wastewater samples. All correlations between the seven-day median number of genome copies/litre wastewater and the time-lagged median seven-day incidence of SARS-CoV-2 cases were significant (p<0.001) for the investigated lag of up to 14 days. Correlation coefficients declined constantly from the maximum of 0.9395 on day 1 to the minimum of 0.8016 on day 14. The B.1.1.529 variant Omicron was detected in wastewater samples collected on November 21, 2021, before its official acknowledgement in a clinical sample by health authorities. In this proof-of-concept study, wastewater-based epidemiology proved a reliable and sensitive surveillance approach, complementing routine clinical testing for mapping COVID-19 pandemic dynamics and observing newly circulating SARS-CoV-2 variants.

Investigating microbial dynamics and potential advantages of anaerobic co-digestion of cheese whey and poultry slaughterhouse wastewaters

Resource recovery and prevention of environmental pollution are key goals for sustainable development. It is widely reported that agro-industrial activities are responsible for the discharge of billions of liters of wastewater to the environment. Anaerobic digestion of these energy rich agro-industrial wastewaters can simultaneously mitigate environmental pollution and recover embedded energy as methane gas. In this study, an assessment of mono- and co-digestion of cheese whey wastewater (CWW) and poultry slaughterhouse wastewater (PSW) was conducted in 2.25-L lab-scale anaerobic digesters. Treatment combinations evaluated included CWW (R1), PSW (R2), 75:25 CWW:PSW (R3), 25:75 CWW:PSW (R4), and 50:50 CWW:PSW (R5). The digestion efficiencies of the mixed wastewaters were compared to the weighted efficiencies of the corresponding combined mono-digested samples. R4, with a mixture of 25% CWW and 75% PSW, achieved the greatest treatment efficiency. This corresponded with an average biodegradability of 84%, which was greater than for R1 and R2 at 68.5 and 71.9%, respectively. Similarly, R4 produced the highest average cumulative methane value compared to R1 and R2 at 1.22× and 1.39× for similar COD loading, respectively. The modified Gompertz model provided the best fit for the obtained methane production data, with lag time decreasing over progressive treatment cycles. PCoA and heatmap analysis of relative microbial abundances indicated a divergence of microbial communities based on feed type over the treatment cycles. Microbial community analysis showed that genus Petrimonas attained the highest relative abundance (RA) at up to 38.9% in the first two cycles, then subsequently decreased to near 0% for all reactors. Syntrophomonas was highly abundant in PSW reactors, reaching up to 36% RA. Acinetobacter was present mostly in CWW reactors with a RA reaching 56.5%. The methanogenic community was dominated by Methanothrix (84.3–99.9% of archaea). The presence of phosphate and Acinetobacter in CWW feed appeared to reduce the treatment efficiency of associated reactors. Despite Acinetobacter being strictly aerobic, previous and current results indicate its survival under anaerobic conditions, with the storage of phosphate likely playing a key role in its ability to scavenge acetate during the digestion process.

Intensification of ozone mass transfer for wastewater treatment using a rotating bar reactor

As one of the advanced oxidation processes (AOPs), ozonation has been widely used in the treatment of textile dyeing wastewater. However, ozonation was limited by the mass transfer process due to the low solubility of ozone in water. In this work, a novel rotating bar reactor (RBR) was developed to enhance ozone-water mass transfer via optimizing its inner structures. The RBR with the internal structure of sieve plates combined with spoiler columns has the best mass transfer performance, which was 249% higher than that of the RBR without these structures. Furthermore, the optimized RBR was adopted to intensify the decolorization of the simulated wastewater of reactive black 5. The ozone dose was used to characterize the introduced ozone mass for treating a liter of wastewater in different reactors. The ozone dose in RBR was 150 mg/L (using O3), which was lower than that in semibatch glass reactor (567 mg/L, using O3/UV/H2O2) and in cylindrical glass cell (506.67 mg/L, using O3/US), reported in the literatures. The results indicated that RBR can achieve the same decolorization rate with less ozone dose, i.e. the RBR is more efficient. The RBR exhibited great potential application in enhancing liquid-film controlling system.

Monitoring COVID-19 spread in Prague local neighborhoods based on the presence of SARS-CoV-2 RNA in wastewater collected throughout the sewer network

Many reports have documented that the presence of SARS-CoV-2 RNA in the influents of municipal wastewater treatment plants (WWTP) correlates with the actual epidemic situation in a given city. However, few data have been reported thus far on measurements upstream of WWTPs, i.e. throughout the sewer network. In this study, the monitoring of the presence of SARS-CoV-2 RNA in Prague wastewater was carried out at selected locations of the Prague sewer network from August 2020 through May 2021. Various locations such as residential areas of various sizes, hospitals, city center areas, student dormitories, transportation hubs (airport, bus terminal), and commercial areas were monitored together with four of the main Prague sewers. The presence of SARS-CoV-2 RNA was determined by reverse transcription – multiplex quantitative polymerase chain reaction (RT-mqPCR) after the precipitation of nucleic acids with PEG 8,000 and RNA isolation with TRIzol™ Reagent. The number of copies of the gene encoding SARS-CoV-2 nucleocapsid (N1) per liter of wastewater was compared with the number of officially registered COVID-19 cases in Prague. Although the data obtained by sampling wastewater from the major Prague sewers were more consistent than those obtained from the small sewers, the correlation between wastewater-based and clinical-testing data was also good for the residential areas with more than 7,000 registered inhabitants. It was shown that monitoring SARS-CoV-2 RNA in wastewater sampled from small sewers could identify isolated occurrences of COVID-19-positive cases in local neighborhoods. This can be very valuable while tracking COVID-19 hotspots within large cities.

Operational parameters optimization for remediation of crude oil-polluted water in floating treatment wetlands using response surface methodology

The application of floating treatment wetlands (FTWs) is an innovative nature-based solution for the remediation of polluted water. The rational improvement of water treatment via FTWs is typically based on multifactorial experiments which are labor-intensive and time-consuming. Here, we used the response surface methodology (RSM) for the optimization of FTW’s operational parameters for the remediation of water polluted by crude oil. The central composite design (CCD) of RSM was used to generate the experimental layout for testing the effect of the variables hydrocarbon, nutrient, and surfactant concentrations, aeration, and retention time on the hydrocarbon removal in 50 different FTW test systems planted with the common reed, Phragmites australis. The results from these FTW were used to formulate a mathematical model in which the computational data strongly correlated with the experimental results. The operational parameters were further optimized via modeling prediction plus experimental validation in test FTW systems. In the FTW with optimized parameters, there was a 95% attenuation of the hydrocarbon concentration, which was very close to the 98% attenuation predicted by the model. The cost-effectiveness ratio showed a reduction of the treatment cost up to $0.048/liter of wastewater. The approach showed that RSM is a useful strategy for designing FTW experiments and optimizing operational parameters.

Comparison of TiO2 catalysis and Fenton's treatment for rapid degradation of Remazol Red Dye in textile industry effluent.

The contamination of water bodies by toxic industrial effluents is a serious threat to environment and the exposed organisms. The treatment of carcinogenic azo dyes in wastewater of grossly polluting textile industry is a major challenge considering the persistent nature of chemical dyes against biological treatment. The present study explores efficacy of advanced oxidation processes—photocatalysis and photo-Fenton, towards degradation of Remazol Red dye in the textile industry effluent. It was observed that both processes can completely remove the colour and approximately 85% mineralization of the dye within reaction time of 60 min and 8 min, respectively. The economic analysis placed photo-Fenton as a cost-effective method with treatment cost of approx. 0.0090 US $/litre of wastewater containing Remazol Red dye. Although, Photocatalysis was relatively slow, it is substantially effective in removal/degradation of colour from textile effluent against the biological treatment. The study concludes that photo-Fenton and Photocatalysis are cost-effective and substantial treatment options for removal of toxicity arising from coloured textile effluents.