Treatment Ponds Research Articles

Breeding of black-winged stilt Himantopus himantopus in muddy sites of a wastewater treatment plant

A stable group of birds has been formed at water treatment facilities. Sewage treatment sites are a well-known nesting place for long-legged waders. Black-winged stilts are included in the Bonn (Appendix II) and Berne (Appendix II) conventions, the AEWA agreement. Listed in the Red Book of Ukraine (1994, 2009) (status – vulnerable). In Ukraine, it is under protection on the territory of the natural reserve fund. The arrival of black-winged stilts waders at the nesting sites was recorded in the second-third decade of April (April 23, 2020; April 17, 2021). Immediately after returning to the nesting areas, the birds begin to build nests and lay eggs. The first eggs in this population were seen on 01.05.2020, 07.05.2021. The process of laying eggs lasted until the end of the first decade of July (08.07.2020). The average clutch size in the nests of Himantopus himantopus decreased from 3.8 ± 0.1 (2020) to 3.5 ± 0.1 (2021). The average egg sizes and their limits have been determined for long-legged waders. The chicks hatched from late May (30.05.2020), throughout June to the first decade of July (02.07.2020). The chicks were able to fly in a month – 29.06.2020. The muddy site of the wastewater treatment ponds of Kharkiv supported Black-winged Stilts until early August. Later, the birds started post-breeding movements. The last adults with juvenile birds were observed on 13.08.2020. Stilts in some years may stay until early October. The reproductive success of the black-winged stilt increased from 35.6% (2020) to 38.8% (2021). On average, 1.3 ± 0.2 (2020) and 1.4 ± 0.3 (2021) chicks fledged from the nests. In 2021, the number of nesting stilts increased, which is apparently due to rainy weather at the beginning of the reproductive period. For the purpose of more effective protection, the nesting settlements of the stilt should be protected and the appearance of people in the nesting places should be prohibited.

Water purification plantations for oil and gas industries in Iran.

Water treatment for human uses is a vital asset to economic development. This article focuses on a combination of physical, biological, and chemical processes. Methods of water treatment require concrete or steel base structures, rendering them heavy, costly, and time-consuming to establish. Water treatment systems should be economically viable and practicable in design for developing societies; hence, structural builds should be simplified. Novel structures, a series of polyethylene cyclonic ponds for water treatment, were built and tested. Tanks were equipped with a settled material central outlet, water side outlet, and a pump shower system that enabled sludge removal without mechanical intervention. A freely flowing vortex was produced, aerated, given a biological treatment, and finally mixed with a chemical treatment step. Test establishment of the batch system enabled improvement in water quality, with removal performance as follows: TSS (total suspended solids) = 98%, UV254 absorbance = 50%, DOC (dissolved organic carbon) = 56%, and turbidity=95%. The batch system builds of the current study required short construction time and were economically priced. Cyclonic ponds are suited to diverse usage. The value may be felt in the improvement of water quality for human consumption, utility, and ecosystem services to counter the extensive pollution caused by oil and gas extraction and other industries.

Wastewater Treatment Process: A Modified Mathematical Model for Oxidation Ponds

Wastewater treatment aims to eliminate as many suspended solids as possible from the remaining water, known as effluent, before it is released into the environment. Pond oxidation methods have been practically proven successful for the wastewater treatment process because of their low construction and maintenance costs. This study aimed to investigate the degradation of wastewater pollutants through an oxidation pond treatment system. The purpose was to observe the relationship between the concentration of bacteria which are phototrophic and coliform, chemical oxygen demand (COD), and dissolved oxygen (DO). In this paper, a modified model consist of a set of an ordinary differential equation (ODE) has been developed by incorporating the Monod Equation. The model was solved numerically using the 4th order Runge Kutta method embedded in the MATLAB software. The sum of squared estimate of errors (SSE) for the modified model was compared with the SSE of the existing model. The results revealed that the modified model demonstrated a lower SSE compared to the existing model. Thus, the modified mathematical model gives better result than the existing model. The model provides an excellent approximation for concentration needed for an oxidized pond to produce good water quality.

The Effectiveness of an Artificial Floating Wetland to Remove Nutrients in an Urban Stream: A Pilot-Study in the Chicago River, Chicago, IL USA

Ever expanding urbanized landscapes are increasingly impacting streams that run through them. Among other stressors, urban streams often are host to elevated concentrations of nutrients, salts, and heavy metals. The pollutants, coupled with high temperatures, are drivers of ecosystem degradation in urban streams. The installation of artificial floating wetlands (AFWs) has been successful in mitigating the effects of urbanization in lakes and wastewater treatment ponds, but rarely have they been tested in streams. This pilot-study examined the ability of an AFW to improve water quality in an urban stream. The small, 90 m2 AFW was installed to improve the aquatic habitat and aesthetics of a small section of the Chicago River, Chicago, IL USA. Water samples and in-situ measurements were collected from the surface and at 0.3 m depth of upstream and downstream of the AFW. Samples were analyzed for nitrate-as-nitrogen, phosphate, chloride, and heavy metals. Comparison of upstream and downstream waters showed that the AFW lowered the concentrations of nitrate-as-nitrogen and phosphate during the growing season by 6.9% and 6.0%, respectively. Nitrate was also removed during the dormant season; however, phosphate was not removed during that time. Plant or microbial uptake of the nutrients are believed to be the dominant mechanisms in the growing season with denitrification serving as the primary pathway in the dormant season. Despite not having a measurable effect on the water temperature, the AFW was an effective means to reduce concentrations of nitrate and phosphorus, decreasing the potential for eutrophication.

Water reuse for aquaculture: Comparative removal efficacy and aquatic hazard reduction of pharmaceuticals by a pond treatment system during a one year study

Aquaculture is increasing at the global scale, and beneficial reuse of wastewater is becoming crucial in some regions. Here we selected a unique tertiary treatment system for study over a one-year period. This experimental ecosystem-based approach to effluent management included a treated wastewater pond (TWP), which receives 100% effluent from a wastewater treatment plant, and an aquaculture pond (AP) that receives treated water from the TWP for fish production. We examined the fate of a wide range of pharmaceutically active compounds (PhACs) in this TWP-AP system and a control pond fed by river water using traditional grab sampling and passive samplers. We then employed probabilistic approaches to examine exposure hazards. Telmisartan, carbamazepine, diclofenac and venlafaxine, exceeded ecotoxicological predicted no effect concentrations in influent wastewater to the TWP, but these water quality hazards were consistently reduced following treatment in the TWP-AP system. In addition, both grab and passive sampling approaches resulted in similar occurrence patterns of studied compounds, which highlights the potential of POCIS use for water monitoring. Based on the approach taken here, the TWP-AP system appears useful as a tertiary treatment step to reduce PhACs and decrease ecotoxicological and antibiotic resistance water quality hazards prior to beneficial reuse in aquaculture.

Ammonia, pH and dissolved inorganic carbon supply drive whole pond metabolism in full-scale wastewater high rate algal ponds

High rate algal ponds are an established cost-effective and efficient upgrade to conventional wastewater treatment ponds for the biological treatment of wastewaters. However, few studies have investigated ecosystem metabolism and its drivers in these ponds. Hourly, daily and seasonal changes in rates of gross primary production, net ecosystem production and ecosystem respiration were determined from automated dissolved oxygen, pH and temperature measurements in full-scale high rate algal ponds over a two-year period. The open water metabolism model was used to assess the dynamics of pond metabolism against a number of measured environmental variables. For the most part, net ecosystem production was positive, meaning that the pond was in net autotrophy, with microalgal photosynthetic production exceeding respiratory organic matter consumption. pH had a negative influence on ecosystem respiration, with respiration rates increasing as diurnal pH increased. Similarly, free ammonia concentration reduced gross primary production rates. Modelled CO2 addition to maintain pH 8, resulted in decreased ecosystem respiration and increased net ecosystem production, particularly in summer with a 50% increase in net ecosystem production. However, modelled CO2 addition did not influence net ecosystem production during winter. The use of the Datasondes coupled with the open water metabolism model provides a cost-effective tool for improved high rate algal pond management through the capture of high frequency metabolism parameters. Better understanding of how the high rate algal pond environment affects both photosynthesis and respiratory losses, will help improve real-time management of the pond, including ammonia and CO2 loading management, to improve effluent quality and biomass yields and reduce excess CO2 off-gassing to atmosphere.

The impact of hydraulic retention time on the performance of two configurations of anaerobic pond for municipal sewage treatment

ABSTRACT Anaerobic ponds have the potential to contribute to low carbon wastewater treatment, however are currently restricted by long hydraulic residence time (HRT) which leads to large land requirements. A two-stage anaerobic pond (SAP) design was trialled against a single-stage control (CAP) over four HRTs down to 0.5 days, to determine the lowest HRT at which the ponds could operate effectively. No statistical differences were observed in particulate removal between the ponds over all four HRTs, suggesting solids loading is not a critical factor in AP design. Significantly higher biogas production rates were observed in the SAP than the CAP at 1.5 d and 1.0 d HRT, and microbial community profiling suggests the two-stage design may be facilitating spatial separation of the anaerobic digestion process along reactor length. Hydrogenotrophic methanogensis dominated over aceticlastic, with acetate oxidisation a likely degradation pathway. Experimental tracer studies were compared to CFD simulations, with the SAP showing greater hydraulic efficiency, and differences more pronounced at shorter HRTs. Greater flow recirculation between baffles was observed in CFD velocity profiles, demonstrating baffles can dissipate preferential flow patterns and increase effective pond volume, especially at high flow rates. The study demonstrates the potential of APs to be operated at shorter HRTs in psychrophilic conditions, presenting an opportunity for use as pre-treatments (in place of septic tanks) and primary treatment for full wastewater flows. Two-stage designs should be investigated to separate the stages of the anaerobic digestion process by creating preferential conditions along the pond length.

IMPROVEMENT OF THE HYDROECOLOGICAL CONDITION OF TEREMNIVSKY PONDS

The article is devoted to the assessment of the current hydroecological condition of Teremnivsky ponds, the factors influencing it, the connection with the hydroecological condition of the Sapalaivka river. The history of research of hydroecological condition of Teremnivsky ponds, features of physical and geographical conditions of locality and anthropogenic influence on ecosystem of ponds are analyzed. The reservoirs are located in the Teremnivskyi district, where low-rise private buildings and a few of industrial enterprises predominate. Ponds and their shores are a place of rest and recreation of local population. It has swimming and sunbathing beaches, shopping and catering facilities. The shores of the ponds are currently insufficiently landscaped and have poor sanitation. The reservoir is a typical floodplain pond in the valley of the river Sapalaivka. Built in the 60's. XX century Recently, the ecological and sanitary condition of ponds has deteriorated, which makes it difficult to use them for recreational purposes. This is largely due to the poor ecological condition of the Sapalaivka river. Teremnivsky ponds in the summer are characterized by eutrophication - the enrichment of reservoirs with nutrients, which is accompanied by increased productivity of the reservoir. Much of the surface of the reservoir is covered with a film of duckweed and other algae. Poor sanitation of the reservoir banks also contributes to eutrophication. Shores are not removed from fallen leaves, household waste. It all gets into the stakes and pollutes them. It is determined that the hydroecological condition of Teremnivsky ponds is most affected by: chemical composition of water, microbiological water pollution, eutrophication of the reservoir in summer, sanitary condition of the reservoir banks, ecological condition of the Sapalaivka river, where the reservoir was created. It is established that the content of certain chemical pollutants in the water of Teremnivsky ponds exceeds their maximum permissible concentration in reservoirs for fishery use. Such water pollution is caused by the ingress of surface runoff from the city, sewage from latrine pits and garbage from the population. Thus, the hydroecological and sanitary condition of Teremnivsky ponds today is unsatisfactory and requires optimization. Previously implemented measures of local environmental programs are analyzed. In 2012-17, on the initiative of the Department of Ecology of the Lutsk City Council, measures were taken to improve the hydroecological condition of the Sapalaivka River. At present, a significant amount of urgent work has been done, and the project is still far from complete. In 2013-2014, landscaping with elements of revitalization of the valley of the Sapalaivka River was carried out. A set of measures for the completion and successful implementation of the project to improve the hydro-ecological condition of Teremnivsky ponds is proposed. It includes: cleaning and tidying up the water area and the surrounding area; technical measures (treatment of surface runoff from the city and prevention of contaminated wastewater; bioremediation measures (treatment of ponds from pollutants already in the water, improving the sanitary condition of water and combating eutrophication of the reservoir).
 Key words: ponds, hydroecological condition of ponds, factors determining the hydroecological condition of ponds, measures to improve the hydroecological condition of ponds.

Health and Safety Management System, Biological Sewage Treatment Ponds in Tehama Region, Yemen

Under the German-Yemeni Financial Co-operation Program three treatments Sewage stations have beendeveloped for the towns of Bajil, Bet Al-Faqih and Zabid in Tehama region.This present investigation work covers the following aspects ,Design and specific characteristics of thestabilisation ponds description of the existing situation, and presents analytical results for key values suchas Biological Oxygen Demand ( BOD) and Dissolved Oxygen( DO), interpretation, problem diagnosis andsuggested remedies.

Isolation and Characterization of Potential Salmonella Phages Targeting Multidrug-Resistant and Major Serovars of Salmonella Derived From Broiler Production Chain in Thailand.

Salmonella is a major foodborne pathogen that causes foodborne disease in humans through consumption of contaminated foods, especially those of animal origin. Multiple Salmonella strains are antibiotic-resistant due to the common use of antibiotics in farm animals, including broiler farms. In this study, an alternative strategy using phage-based treatment was evaluated against Salmonella isolated from the broiler production. The prevalence of Salmonella spp. showed up to 46.2 and 44.4% in bedding samples from the broiler farms located in eastern and southern Thailand, respectively. Overall, 21 samples (36.2%) were positive for Salmonella and eight serovars were recovered from cloacal swabs, bedding materials (rice husk), and boot swabs collected from five farms. Up to 20 Salmonella phages were isolated from seven water samples from wastewater treatment ponds, a river, and a natural reservoir in Songkhla province. Isolated phages were investigated, as well as their lysis ability on eight target Salmonella serovars derived from broiler farms, five foodborne outbreak-related serovars, and 10 multidrug-resistant (MDR) serovars. All phages showed a strong lytic ability against five serovars of Salmonella derived from broiler farms including Kentucky, Saintpaul, Schwarzengrund, Corvalis, and Typhimurium; three foodborne outbreak serovars including Enteritidis, Typhimurium, and Virchow; and eight MDR serovars including Agona, Albany, Give, Kentucky, Typhimurium, Schwarzengrund, Singapore, and Weltevreden. Three phages with the highest lysis potential including vB_SenS_WP109, vB_SenS_WP110, and vB_SenP_WP128 were selected for a phage cocktail preparation. Overall, a phage cocktail could reduce Salmonella counts by 2.2–2.8 log units at 6 h of treatment. Moreover, Salmonella did not develop a resistant pattern after being treated with a phage cocktail. Findings here suggest that a phage cocktail is an effective biocontrol to combat Salmonella derived from broiler production chain, other serovars linked to foodborne outbreaks, and MDR serovars.

Long term evaluation of a pilot scale multimodal algal bioprocess for treatment of municipal wastewater

The feasibility of Multimodal Algal-bacterial Bioprocess (MAB) for the treatment of primary clarified municipal wastewater was demonstrated at a pilot-scale MAB system (0.2 m3/d) installed and operated in Corvallis, Oregon, USA for one year. The system consisted of an anaerobic reactor; mixotrophic and phototrophic ponds followed by algal settlers and a final wetland cell (WC). The wastewater treatment performance was monitored weekly over the one-year period in terms of onsite parameters as pH, dissolved oxygen (DO), oxidation reduction potential (ORP), electrical conductivity (EC), total dissolved solids (TDS),turbidity and chemical parameters (COD, Nitrate-N, Amm.-N and reactive phosphorus). Algal biomass production and algal community analysis in the MAB was determined regularly. A continuous improvement in the mean DO (1.57–13.98 mg/L) and ORP (−140 to +86 mV) was observed throughout the study period. Higher mean pH (8.62) and DO (14 mg/L) in the ponds indicated high algal photosynthesis. The pilot-scale system maintained an average low final effluent turbidity (14.2 NTU), TSS (<30 mg/L) and COD concentrations (~78.3 mg/L) and achieved removal of nitrogen as Amm.-N (76%) and Nitrate-N (34%), phosphorus (DRP: 51%) throughout the experimental period. Particularly in summer, the overall treatment performance was high (70% COD removal; 78% Amm.-N removal; 38% Nit.-N removal; 53% DRP removal) owing to high algal-bacterial activity. The community analysis showed a predominance of diatoms and cyanophycean members in the winter and chlorophycean members especially species Chlorella (~80%) during summer. The average biomass productivities (VSS) in the treatment ponds ranged from 6.75 g/m2/d during winter to 11.47 g/m2/d during summer. Overall, the MAB can effectively treat municipal wastewater; produce quality final effluent and algal bioproducts with minimum energy inputs.

Spatiotemporal variations in the composition of algal mats in wastewater treatment ponds of tannery industry.

Wastewater Treatment Pond (WTP) is an effective remediation technology for economically developing nations. Although it's excessive organic and nutrient loads with higher water logging time triggers mixed and unprofitable microalgal mats. This may serve as a seeding source for Cyanobacterial bloom in receiving waterbodies. Since,to maintain the growth of desirable algal species in WTPs, understanding towards environmental regulation and algal mat composition is important, especially for tropical countries, like India. In this study, biological treatment pond (BTP) and outlet pond (OP), of a tannery effluent treatment plant in eastern coast of India, were chosen for surveying the algal community composition concerning ecological parameters. Nearly, both the ponds were polluted, but the diversity was lower in BTP due to its elevated nutrient content (Ammonia 173mg L-1) and higher persistent organic matters (COD 301.7mg L-1) than OP. Using canonical correspondence analysis, seasonal variations showed higher species abundance during early summer compared to other seasons. A total of 37 taxa forming thick algal mats were recorded. The matrix of mats was mainly composed of Cyanobacterial members such as Phormidium, Leptolyngbya, Spirulina, and Pseudanabaena, followed by diatoms, especially Amphora and Nitzschia. Diatoms commonly occurred as embedded component in the entangled matrix of blue-green algal filaments. Hierarchical cluster analysis was employed to group all these taxa based on their seasonal appearance and abundance. This year-long intensive study revealing seasonal algal mat composition patterns in these WTPs will ultimately safeguard the livelihood and security of adjoining localities through proper site-specific pollution control.

Assessment of performance of wastewater stabilization ponds using faecal indicator bacteria reduction efficiency in a tropical environment

Egerton University (EU) uses Wastewater Stabilization Ponds (WSPs) for wastewater treatment. An adjoining wetland with gravel bed substrate and freesurface flow meant to polish discharge before releasing into River Njoro is currently non-operational. The current study aimed at establishing the performance of WSPs in terms of concentration and reduction efficiencies of Faecal Indicator Bacteria (FIB); Total Coliforms (TC) and Escherichia coli (E. coli). Wastewater samples were collected weekly for one month from mid- November to mid-December 2017. Total Coliforms and E. coli were isolated using selective and differential media following Membrane Filtration (MF) method. Colonies were cultured on Chromocult Coliform Agar (CCA) and enumerated using standard procedures for examination of water and wastewater. The results were expressed as Colony Forming Units (CFUs) per 100 ml of the original sample. The inlet showed highest concentration of FIB which reduced along the treatment pathway. Total Coliforms and E. coli ranged between 2.5 × 108 - 2.9 × 1011 and 5.9 × 105 - 1.8 × 1010 CFUs/100 ml respectively with cumulative reduction efficiencies between 2 to 4 log units for E. coli and 2 to 3 log units for TC in the two maturation ponds. Although concentration of FIB in EU WSPs reduces along the treatment pathway, the effluent quality is above recommended international standards for discharge into surface waters. The trend is attributed to lack of frequent monitoring, insufficient maintenance, together with short- circuiting effect due to by-passing of wastewater in the design of the new pond system.

Coupled microalgal–bacterial biofilm for enhanced wastewater treatment without energy investment

In view of water-resource depletion, treated wastewater can serve as an alternative source for crop irrigation. However, conventional wastewater-treatment plants are energy-intensive and costly to construct and operate, especially for lower middle-income countries. The present study focused on improving the quality of wastewater by incorporating a coupled microalgal–bacterial biofilm (CMBB) treatment in wastewater ponds. Standard polyether sponges were dipped in raw wastewater samples to enhance biofilm development on them. The enriched sponges were used to treat wastewater, with or without external energy for aeration. Wastewater parameters were analyzed during the enrichment and treatment processes. The CMBB technology and aeration resulted in similar improvement of effluent quality, but the former saved on energy costs, and reduced total chemical oxygen demand (COD) by 36 % within 24 h and 71 % within 4 days; the values of biochemical oxygen demand (BOD), ammonium and phosphates decreased by 80 %, 64 % and 95 %, respectively, within 7 days. The resultant COD and BOD values were below the maximum allowed for reuse and discharge.

Pilot-Scale Investigation of Floating Treatment Wetlands as Retrofits to Waste-Stabilization Ponds for Efficient Domestic Wastewater Treatment

This study investigates the efficacy of floating treatment wetlands (FTWs) for retrofitting waste-stabilization ponds (WSPs) operating in cold continental climates, such that in Alberta, Canada. The objective was to determine whether WSPs augmented with FTWs could achieve equal or superior treatment efficiency at shorter hydraulic retention times (HRTs of 25–45 days) than those required in the conventional WSPs (60–365 days). A field study was carried out on treatment of domestic wastewater in a two-stage pilot-scale FTW mesocosm (i.e., FTW treatment train composed of Stage 1 and Stage 2 FTW cells (S1-FTW→S2-FTW), with an overall volume of 84 m3 and 41.85 m3 per cell). An identical system without FTW served as a control (i.e., control treatment train of S1-C→S2-C). Overall, the FTW-augmented WSP system achieved greater treatment of 5-day biochemical oxygen demand (BOD5), total suspended solids (TSS), total nitrogen (TN), ammonium nitrogen (NH4+-N), dissolved reactive phosphorus (DRP), and total phosphorus (TP) than the control. The corresponding removal efficiencies were 91.5% versus 85.0%, 91.3% versus 87.7%, 85.0% versus 75.6%, 93.9% versus 86.1%, 77.6% versus 57.7%, and 75.8% versus 58.7%, with a statistically significant difference (p<0.05) for all except TSS. This difference in performance resulted from the better performance of the Stage 1 FTW cell for BOD5, TN, and NH4+-N removal, and the Stage 2 FTW cell for DRP and TP removal. Simultaneous nitrification-denitrification (SND) occurred in the FTW treatment train, whereas only nitrification occurred in the control treatment train, which resulted in statistically higher TN removal efficiency in the former. Contribution of plant uptake to phosphorus removal was marginal (6.76%) and adsorption-desorption on solid particles was assumed to be the major removal pathway. The FTWs generally decreased the physicochemical parameters, with stronger effects on diurnal variations than seasonal fluctuations. The effect of FTW on daily physicochemical conditions played a key role in superior performance of FTW treatment.

A new method for in-situ treatment of waste gas scrubbing liquid containing both NH3 and H2S based on sulfur autotrophic denitrification and partial nitrification-Anammox coupling system

In this study, an integrated device with scrubbing and biochemical treatment functions was used, and partial nitrification (PN)-Anammox and sulfur autotrophic denitrification (SADN) processes were coupled in a biochemical treatment pond to explore the feasibility of in-situ autotrophic removal of NH3 and H2S. The results showed that the removal efficiency of NH3 and H2S in waste gas are 95% and 87.5% respectively. The scrubbing liquid was efficiently treated in the biochemical treatment pond. Nitrogenous compounds weren’t accumulated in liquid and converted to N2 by SADN and PN-Anammox coupling system. S2− was mainly used by SADN process to reduce NO3−. The scrubbing liquid processed by the biochemical treatment pond was refluxed to the scrubber to achieve continuous absorption of NH3 and H2S. Microbial community and functional microbial analysis showed that the PN-Anammox and SADN processes were the main processes to achieve the conversion of pollutants in the scrubbing liquid.

Palm Oil Mills Odour Emission Survey based on Different POME Treatment System

Odorous gaseous such as ammonia and hydrogen sulphide produced by anaerobic bacteria are emitted when palm oil mill effluent (POME) is treated via anaerobic digestion. The Department of Environment (DOE) under the jurisdiction of the Air Division has proposed an odour emission limit of 12,000OUm&lt;sup&gt;-3&lt;/sup&gt; at source sample for Malaysian palm oil mills recently. The objective of this paper is to investigate the odour concentration at effluent treatment area within palm oil mills which practise different types of common POME treatment systems such as Open Ponds Treatment, Covered Lagoon and Digester Tank. The odour source grabbed samples from the respective treatment plants were assessed according to MS 1963:2007 Air Quality – determination of odour concentration by dynamic olfactometry. In addition in-situ odour concentration surrounding the respective project sites have been measured based on enhanced procedures adapted from VDI3940 Grid Method. The survey results showed that odour emitted from Open Ponds Treatment was having highest concentration while Digester Tank was having the lowest concentration due to quarantine factor. None of the observations comply the DOE proposal. Thus, alternative approaches need to be counter proposed in the legislation drafting so that the millers compliance could be ensured while avoid the public sensory annoyance complaints.

Comparison of faecal indicator and viral pathogen light and dark disinfection mechanisms in wastewater treatment pond mesocosms

This study compared light and dark disinfection of faecal bacteria/viral indicator organisms (E. coli and MS2 (fRNA) bacteriophage) and human viruses (Echovirus and Norovirus) in Wastewater Treatment Pond (WTP) mesocosms. Stirred pond mesocosms were operated in either outdoor sunlight-exposed or laboratory dark conditions in two experiments during the austral summer. To investigate wavelength-dependence of sunlight disinfection, three optical filters were used: (1) polyethylene film (light control: transmitting all solar UV and visible wavelengths), (2) acrylic (removing most UVB <315 nm), and (3) polycarbonate (removing both UVB and UVA <400 nm). To assess different dark disinfection processes WTP effluent was treated before spiking with target microbes, by (a) 0.22 μm filtration to remove all but colloidal particles, (b) 0.22 μm filtration followed by heat treatment to destroy enzymes, and (c) addition of Cytochalasin B to supress protozoan grazing. Microbiological stocks containing E. coli, MS2 phage, Echovirus, and Norovirus were spiked into each mesocosm 10 min before the experiments commenced. The light control exposed to all sunlight wavelengths achieved >5-log E. coli and MS2 phage removal (from ~1.0 × 106 to <1 PFU/mL) within 3 h compared with up to 6 h in UV-filtered mesocosms. This result confirms that UVB contributes to inactivation of E. coli and viruses by direct sunlight inactivation. However, the very high attenuation with depth of UVB in WTP water (99% removal in the top 8 cm) suggests that UVB disinfection may be less important than other removal processes averaged over time and full-scale pond depth. Dark removal was appreciably slower than sunlight-mediated inactivation. The dark control typically achieved higher removal of E. coli and viruses than the 0.22 μm filtered (dark) mesocosms. This result suggests that adsorption of E. coli and viruses to WTP particles (e.g., algae and bacteria bio-flocs) is an important mechanism of dark disinfection, while bacteria and virus characteristics (e.g. surface charge) and environmental conditions can influence dark disinfection processes.

Contamination of Urban Stormwater Pond Sediments: A Study of 259 Legacy and Contemporary Organic Substances.

Stormwater ponds improve water quality by facilitating the sedimentation of particles and particulate contaminants from urban runoff. Over time, this function entails the accumulation of contaminated sediments, which must be removed periodically to maintain a pond’s hydraulic and treatment capacity. In this study, sediments from 17 stormwater sedimentation facilities from four Swedish municipalities were analyzed for 259 organic substances likely to be found in the urban environment. A total of 92 substances were detected in at least one sample, while as many as 52 substances were detected in a single sample. A typical profile of urban contamination was identified, including polychlorinated biphenyls, polycyclic aromatic hydrocarbons, organotins, aliphatic hydrocarbons, phthalates, aldehydes, polybrominated diphenyl ethers, perfluorinated substances, and alkylphenols. However, levels of contamination varied greatly between ponds, influenced heavily by the dilution of urban pollutants and wear particles from other sources of particles such as eroded soil, sand, or natural organic matter. For 22 of 32 samples, the observed concentrations of at least one organic substance exceeded the regulatory threshold values derived from toxicity data for both sediment and soil.

Dissemination of Extended-Spectrum-β-Lactamase-Producing Enterobacter cloacae Complex from a Hospital to the Nearby Environment in Guadeloupe (French West Indies): ST114 Lineage Coding for a Successful IncHI2/ST1 Plasmid.

Wastewater treatment plants are considered hot spots for antibiotic resistance. Most studies have addressed the impact on the aquatic environment, as water is an important source of anthropogenic pollutants. Few investigations have been conducted on terrestrial animals living near treatment ponds. We isolated extended-spectrum-β-lactamase Enterobacter cloacae complex-producing strains from 35 clinical isolates, 29 samples of wastewater, 19 wild animals, and 10 domestic animals living in the hospital sewers and at or near a wastewater treatment plant to study the dissemination of clinically relevant resistance through hospital and urban effluents. After comparison of the antibiotic-resistant profiles of E. cloacae complex strains, a more detailed analysis of 41 whole-genome-sequenced strains demonstrated that the most common sequence type, ST114 (n = 20), was present in human (n = 9) and nonhuman (n = 11) samples, with a close genetic relatedness. Whole-genome sequencing confirmed local circulation of this pathogenic lineage in diverse animal species. In addition, nanopore sequencing and specific synteny of an IncHI2/ST1/blaCTX-M-15 plasmid recovered on the majority of these ST114 clones (n = 18) indicated successful worldwide diffusion of this mobile genetic element.