Municipal Treatment Plant Research Articles

Physical and Chemical Characterization of Sustainable Green Adhesives Derived from Municipal Treatment Plant Sludges

Adhesive formulations derived from sustainable feedstocks, like waste-activated sludge and biosolids from wastewater treatment plants, are developed due to protein-based adhesives receiving attention for their low-cost, resourcefulness, and minimal ecological footprint. The protein composition and associated dynamic changes of the adhesive formulations were studied via gel permeation chromatography, which detailed a molecular size distribution of 8.72 × 105 g/mol for the adhesive formulation and 6.89 × 103 g/mol for the dewatered biosolid base fraction, which confirms the formation of multiple protein functional groups combining to form the larger adhesive molecules. Further analysis determined the types of proteins present in the dewatered biosolids as glutelin, prolamin, globulin, and albumin proteins, with the glutelin proteins as the most prevalent, as thus likely responsible for adhesive formation. The rheological properties of the novel protein adhesive were also studied to interpret the structure of the adhesives, which detailed the findings of viscoelastic properties and flow behaviors of each adhesive in relation to the wastewater treatment plant sample location, which yielded higher flow points, storage moduli, and loss moduli for the dewatered biosolids in comparison to the waste-activated sludge and biosolid adhesives, which correlates with the higher solids content of the dewatered biosolids and potentially cell rupturing when exposed to filtration stress.

Detecting and sourcing GHGs and atmospheric trace gases in a municipal waste treatment plant using coupled chemistry and isotope compositions

Landfill operations and waste processing facilities are important and highly heterogeneous sources of both greenhouse gases (GHGs) and non-GHG air pollutants in the atmosphere. This arises the need for detailed apportionment of waste sources in order to locate and subsequently reduce emissions from landfills. Here, a time series of in situ measurements of atmospheric trace gases and spatial allocation of specific emission source types under different processing phases and environmental conditions were conducted in and in the surroundings of a Municipal Solid Waste Treatment Plant (MSWTP) in south-western Poland. Results revealed that several individual GHG sources dominated across the waste processing facility and that GHGs concentrations displayed spatial seasonality. An increase in the ground-level CH4 concentrations, from ∼ 30.3 to 56.3 ppmv, was observed close (∼5 – 10 m) to the major emission sources within the MSWTP. While hotspot areas generally yielded elevated CH4 concentrations near the soil surface, these were relatively low (2.4 to 8.9 ppmv) along the facility’s fence line. The study of the corresponding δ13C delineated the extent of dispersion plumes downwind emission hotspots, characterized by a 13C depletion (around 4.0 ‰) in the atmospheric CH4 and CO2. For CH4, emissions were isotopically discriminated between the extraction wells at active quarters/cells (δ13C = –58.3 ± 1.1 ‰) and biogas produced in the biological waste treatment installation (δ13C = –62.7 ± 0.7 ‰). Most of the trace compounds (non-methane hydrocarbons, halocarbons, oxygen-bearing organic gases, ketones, nitrogenous and sulphurous gases, and other admixture compounds) detected at the ground surface were linked to the CH4- and CO2-rich spots. Despite the relatively high variability in the concentrations of organic and inorganic compounds observed at the MSWTP active zones, our results suggest that they do not have a meaningful impact on the surrounding air quality.

Deciphering the degradation of sulfonamides by UV/chlorination in aqueous solution: kinetics, reaction pathways, and toxicological evolution

UV/Cl is a cost-effective process and is often used in municipal water treatment plants as well as in industrial applications. UV/Cl method is found highly effective in degrading contaminants, including pathogens, The conventional methods for water treatment have been proven inefficient for the complete elimination of pollutants and generate harmful by-products in the environment. This study evaluated the efficacy of three different treatment methods, chlorination alone, UV photolysis, and UV/Cl, for the degradation of sulfonamides (SAs) in water. The results highlighted that UV/Cl treatment was an efficient method for enhancing the degradation of sulfisoxazole (SFX), sulfadimethoxine (SAT), and sulfaguanidine (SG), with substrates degrading in 5, 6.5, and 4 min. The study also investigated the reactive species generated in the UV/Cl system and found that ·OH was the species responsible for the elimination of SFX. Additionally, the study explored the intermediate products generated during the degradation of SFX under the UV/Cl system, identifying VI distinct degradation pathways. The presence of ·OH radicals significantly enhanced the degradation of SFX, while some chlorine species also contributed to the degradation. The study predicted the toxicity of degradation products from the UV/Cl system using the ECOSAR (Ecological Structure Activity Relationships) program and found that the final degradation products of SFX were non-toxic, but concerns were raised about acute toxicity.

Odor control technologies for municipal solid waste mechanical biological treatment plant: a review

Odor control technologies for municipal solid waste mechanical biological treatment plant: a review

Applying Microbial Source Tracking Techniques for Identification of Pathways of Faecal Pollution from Water Sources to Point of Use in Vhembe District, South Africa

A safe water supply is a necessity, but it remains one of the backlogs of services rendered in rural areas of developing countries. This leads to vulnerable communities using water from available sources that is unsafe as it is contaminated with faecal matter. Microbial source tracking (MST) methods are gold-standard techniques that detect the exact sources of faecal contamination. This study, therefore, tracked and identified the exact sources of faecal contamination from the catchment to the point of use in rural areas of Vhembe District Municipality. Collected water samples (n = 1048) were concentrated by membrane filtration for the enumeration and detection of E. coli, followed by DNA extraction. The extracted DNA was subjected to a quantitative polymerase chain reaction (qPCR) to track target host-specific Bacteroidales genetic markers from the water source to the point of use. Rivers and dams exhibited maximum E. coli counts of up to 90 CFU/100 mL during the wet season and up to 50 CFU/100 mL during the dry season. Due to the effective treatment of these water sources, no E. coli bacteria were detected in any of the sampled municipal drinking water treatment plants at the point of treatment, while this indicator bacterium was detected at the point of use (households), with a maximum of 4 CFU/100 mL recorded during both the wet and dry seasons. Overall, the most prevalent MST marker exhibited during the wet season was BacCan (dog-associated, 6.87%), followed by BacCow (cow-associated, 5.53%), while Pig-2-Bac (pig-associated, 2.48%) was the least prevalent. The most prevalent marker exhibited during the dry season was BacCan (5.34%), followed by BacCow, with Pig-2-Bac (1.72%) being the least prevalent. A positive correlation (r = 0.31, p = 0.001) was established between the presence of the MST markers and detected E. coli from water sources to the point of use. The knowledge of the faecal contamination attributes in both public and domestic domains will assist in developing prevention and control strategies.

Green business process management in a Polish municipal waste treatment plant-regional case study

Despite COVID-19, the world economy still contributes to the growth of production and consumption worldwide. Waste disposal, recycling management and energy generation are challenges for many companies in developing economies, including Poland. This article aims to assess the operation of a municipal waste treatment plant (MWTP) from the perspective of green business process management (BMP) solutions. The processes implemented in the MWTP were discussed, with specific consideration of the mechanical waste processing (sorting) process, including the reuse and recycling of materials, composting, energy production (anaerobic process), landfill storage and efficiency parameters of the sorting line. A sustainable waste management system was identified; the cost as well as social and environmental perspectives were analyzed. Also, strategic goals and key performance indicators were considered. The performed analysis included costs, environmental criteria and key environmental indicators. This paper has shown the successful implementation of green BPM, with potential cost and material savings results. The findings of this case study are expected to inspire other waste management companies to adopt green BPM. The presented case study might help raise awareness and promote the implementation of green BPM in municipal plants in Eastern and Southern Europe.

Taxonomic report of filamentous fungi presents in sewage waste sludge with biotechnologi-cal potential

There is few information regarding the identification of filamentous fungi present in sewage sludge, the importance of these microorganisms lies in the potential use they have in the food, pharmaceutical and agri-environmental industries as they are beneficial in the remediation of water, sludge and soil contaminated by Heavy metals and hydrocarbons also contribute to the adsorption of nutrients by crops. The use of residual sludge once decontaminated by these microorganisms can be used in agriculture as soil structure improvers, organic fertilizers and as an amendment to prevent soil erosion. The objective of this research was to characterize and identify fast and medium-growing filamentous fungi from sewage sludge. The residual sludge was collected directly from the thickness of the municipal water treatment plant of Cd. Victoria, Tamaulipas, Mexico. Subsequently, the fungi were isolated on agar plates and identified using morphological characters of the colonies and by PCR and diana sequences. The species identified were: Trichoderma longibrachiatum, Aspergillus terreus, Tylopilus porphyrosporus and Aspergillus fumigatus. Being the first report for Mexico of fungal species that grow in residual sludge from water treatment plants. The molecular characterization of the species of filamentous fungi found in sewage sludge will allow progress in research focused on knowing the advantages and biological and chemical mechanisms of these microorganisms for the development of biotechnological processes and products, with high agricultural potential and environmental.

Wastewater surveillance of antibiotic resistance and class 1 integron-integrase genes: Potential impact of wastewater characteristics on genes profile

Antibiotic resistance (AR) is a major global health concern, but current surveillance efforts primarily focus on healthcare settings, leaving a lack of understanding about AR across all sectors of the One Health approach. To bridge this gap, wastewater surveillance provides a cost-effective and efficient method for monitoring AR within a population. In this study, we implemented a surveillance program by monitoring the wastewater effluent from two large-scale municipal treatment plants situated in Isfahan, a central region of Iran. These treatment plants covered distinct catchment regions and served a combined population about two million of residents. Furthermore, the effect of physicochemical and microbial characteristics of wastewater effluent including biological oxygen demand (BOD), chemical oxygen demand (COD), total suspended solids (TSS), temperature, total coliforms and Escherichia coli concentration on the abundance of ARGs (blaCTX-M, tetW, sul1, cmlA, and ermB) and class 1 integron-integrase gene (intI1) were investigated. Sul1 and blaCTX-M were the most and least abundant ARGs in the two WWTPs, respectively. Principal Component Analysis showed that in both of the WWTPs all ARGs and intI1 gene abundance were positively correlated with effluent temperature, but all other effluent characteristics (BOD, COD, TSS, total coliforms and E. coli) showed no significant correlation with ARGs abundance. Temperature could affect the performance of conventional activated sludge process, which in turn could affect the abundance of ARGs. The results of this study suggest that other factors than BOD, COD and TSS may affect the ARGs abundance. The predicted AR could lead to development of effective interventions and policies to combat AR in the clinical settings. However, further research is needed to determine the relationship between the AR in wastewater and clinical settings as well as the effect of other influential factors on ARGs abundance.

Performance evaluation of trommel screens: A case study of a municipal solid waste treatment plant

The efficient and effective operation of trommel screens is essential for the economic and environmental sustainability of mechanical biological treatment (MBT) based solid waste treatment plants. The present study evaluated the performance of four trommel screens (aperture sizes of 80, 32, 16, and 4 mm) being used at the MBT plant of the Municipal Corporation Karnal, India. The performance of trommel screens was evaluated at a fixed speed of rotation and inclination angle. For optimum performance, trommel screens must be operated at a particular range of feed rates with regular cleaning every four hours of operation. The organic recovery achieved by 80 mm and 32 mm aperture size trommel screen was 26.95 % and 95.82 %. The organic quality improvement achieved by 80 mm and 32 mm trommel screens was 122.50 % and 108.89 %. The trommel screen's heating value improvement and energy recovery ranged from 70.68 % to 135.16 % and 28.27 % to 98.74 %, respectively. The oversized fractions of trommel screens of opening sizes 80 mm and 32 mm meet the fuel specification prescribed by the Indian Solid Waste Management Rules 2016. The trommel screen's Specific Energy Consumption (SEC) ranged from 0.63 kWh/tonne to 5.66 kWh/tonne. The learnings and outcomes of this study are helpful for designers, policymakers, operators of solid waste treatment plants, and researchers.

How to Pump Wastewater Treatment Chemicals

Municipal water treatment plants are demanding environments for chemical metering pumps

Electrocatalytic detection of Hg(II) using a platinum electrode modified with composite film of cobalt(II) phthalocyanine tetra-substituted with 1-(methoxymethyl)-benzotriazole groups and co-electropolymerized polypyrrole

The presence of mercury adversely affects the daily lives of humankind due to its acute toxicity and environmental persistence. Therefore, the development of cost-effective smart materials which can allow the real time, ultrasensitive and discriminatory monitoring of mercury concentrations in industrial and municipal water treatment plants is an imperative. It is foreseen that this proposed water quality assurance measure will be of utmost importance to identify the culprits for the wide prevalence of this heavy metal ion in the environment. Herein, a platinum electrode (Pt) was modified via the simultaneous electropolymerization of polypyrrole (PPy) and the co-electrodeposition of tetra-[4-((1H-benzotriazole)methoxy)phthalocyaninato]cobalt(II) (CoPc-Bzt, 2, (Btz = benzotriazole)). The complementary electrode modification processes were performed in a 1:1 (v: v) DMF: acetonitrile containing 1 M tetrabutylammonium hexafluorophosphate electrolyte solution over 20 cycles using cyclic voltammetry to afford the chemically modified electrode (CME), Pt|PPy/2. Differential pulse anodic stripping voltammetry (DPASV) was used to detect Hg(II) ions using the CME within a 10 µM to 100 µM linear range while calculated limits of detection and quantification (LOD and LOQ) were determined as 3.11 and 10.00 µM, respectively. The analytical performance of the CME rendered a statistically accepted percentage recovery (97.4%) whereas that of Inductively Coupled Plasma – Optical Emission Spectroscopy (ICP-OES) is 112.3%.

The Autocatalytic Chemical Reaction of a Soluble Biopolymer Derived from Municipal Biowaste.

The paper discusses the perspectives of further implementation of the autocatalytic properties of a soluble biopolymer (SBP) derived from municipal biowastes for the realisation of a biorefinery producing value-added bio-products for consumer use. The reaction of an SBP and water is reported to cause the depolymerisation and oxidation of the pristine SBP organic matter with the formation of carboxyl-functionalised polymers having lower molecular weight and CO2. These findings demonstrate the oxidation of the SBP via water, which could only occur through the production of O and OH radicals catalysed by the SBP. According to the adopted experimental plan, the anaerobic digestate supplied by an Italian municipal biowaste treatment plant was hydrolysed in pH 13 water at 60 °C. The dry product was re-dissolved in plain water at pH 10 and used as a control against the same solution with hydrogen peroxide at 0.1-3 H2O2 moles per SBP carbon mole added. The control and test solutions were kept at room temperature, in the dark or in a climatic chamber under irradiation with simulated solar light, until the pH of the solutions remained constant. Afterwards, the solutions were processed to recover and analyse the crude soluble products. The present work reports the results obtained for the control solution and for the test solutions treated in the presence and absence of H2O2, with and without pH control, in the dark and under irradiation with simulated solar light.

The occurrence of Antibiotic-Resistant Escherichia coli in the Upper Citarum River and surrounding wastewater effluents

Wastewater has the potential to introduce antibiotic-resistant bacterial contamination into the adjacent river, posing environmental health risks to surrounding community. However, there is limited data on the bacterial resistance pattern in aquatic environments of developing countries. This study aimed to explore the hazard level of Antibiotic-Resistant Escherichia coli from effluents and river water based on the enumeration and resistance pattern towards thirteen antibiotics of varying potency. Escherichia coli enumeration was performed on samples collected from nine segments of the Upper Citarum River, and the effluents of two hospitals, six farms, five pharmaceutical companies, and two municipal treatment plants. Agar dilution on Chromocult® Coliform Agar ES was utilized to profile antibiotic susceptibility. The results show that Escherichia coli from farm wastewater has the highest average number (43.347 CFU/100mL) and the widest range of antibiotic resistance (up to eight type), followed by Escherichia coli from domestic, hospital and pharmaceutical effluent. Meropenem-resistant Escherichia coli is already detected in all effluent sources. Escherichia coli in the river water was resistant to thirteen types of antibiotics, and the load was increasing downstream. It is important to take immediate and effective measures to address bacterial resistance occurrence in the aquatic environments.

FUZZY DISSOLVED OXYGEN CONTROLLER APPLIED IN ACTIVATED SLUDGE PROCESS

Roughly 80% of waste water treatment plants are based on active sludge technique due to its simplicity and reliability. Under aerobic conditions microorganisms can grow on some organic pollutants present in the wastewater. As such, dissolved oxygen control is paramount in order to save energy, improve effluent quality and achieve high nitrogen removal. However, due to the nonlinearities of bioprocesses, dissolved oxygen (DO) is a challenge in terms of variable control. In Suzano municipal Waste Water Treatment Plant (WWTP) - located in São Paulo Metropolitan area - dissolved oxygen control is conducted based on a set of heuristic rules stablished by skilful operators. Although yielding satisfactory results, staff training is time consuming. Under the light of these facts, this study aimed to develop a fuzzy DO controller applied to activated sludge process. Data collection and implementation of the fuzzy control system were conducted in bioreactors at Suzano WWTP. Three fuzzy inference systems were developed: “aerator number”, “aerator speed” and “submergence height”. The fuzzy controller was tested and calibrated with a dynamic simulator and implemented as a supervisory controller, yielding positive results. Statistically, dissolved oxygen mean was 1.75 mg/L with a standard deviation of 0.25 mg/L. Based on the results the application of fuzzy logic for DO control in activated sludge process has proven not only viable, but an interesting control option. Fuzzy logic overcame DO non-linearities by translating an empirical knowledge into a linguistic, rule-based controller. It is a promising technique, bringing significant advances, both in treatment performance and energy efficiency.

Efficient recovery and characterization of humic acids from municipal and manure composts: A comparative study

The recovery of humic acids from low-quality compost obtained in municipal solid waste treatment plants provides opportunities for its valorization. This study compares the recovery and properties of the humic acids obtained from municipal mixed waste compost (MMWC) and manure compost. The effects of temperature, time, and KOH concentration on the ratio of humic acids in the extracted liquid and the content of organic carbon of the precipitates were investigated by response surface methodology. Optimal conditions were 30 °C and 24 h for both composts, with a KOH concentration of 0.53 M for MMWC and 0.25 M for manure compost. The manure compost provided a liquid extract richer in humic acids than MMWC (76.6 % vs. 33.7 %), but the precipitates presented similar organic carbon contents (38.1 % vs. 42.4 %). Regarding composition, both humic acids presented higher organic carbon and nitrogen contents than the composts used as feedstock. The extraction and further precipitation of humic acids reduced the concentration of heavy metals. Humic acids from manure compost have a slightly higher average molecular weight (2650 Da) than those from MMWC (1980 Da), while both present similar C/N ratios and degree of aromaticity. Most contaminants of emerging concern present in the original composts were not detected in the humic acids. Thus, it was demonstrated that MMWC constitutes an attractive source of humic acids with properties similar to those obtained from a high-quality compost and, therefore, with potential economic value.

Comparison of 17β-estradiol, bisphenol-A and caffeine concentration levels before and after the water treatment plant.

This article compares the concentration levels of 17β-estradiol (E2), bisphenol-A (BPA) and caffeine (CAF) in the Sinos River, Brazil, which is a source of drinking water and the presence of contaminants after the conventional treatment in a municipal water treatment plant (WTP). A total of nine sampling campaigns were carried out, with sample collection in the Sinos River, upstream and downstream of the WTP, in addition to a drinking water sample (DW). The samples were extracted with solid phase extraction (SPE) and the concentration by liquid chromatography coupled to mass spectrometry (LC-MS). The maximum concentration in the Sinos River was 6,127.99 ng·L-1 for E2, 3,294.63 ng·L-1 for BPA and 1,221.95 ng·L-1 for CAF. In drinking water, the concentration range of E2, BPA and CAF was from less than the Detection Limit (DL) up to 437.50 ng·L-1, <DL up to 2,573.34 ng·L-1 and <DL up to 832.30 ng·L-1, respectively. In conclusion, the concentrations of these pollutants present in the Sinos River are high, which may represent a negative environmental impact on this water source. Drinking water indicates the need for a new treatment process that could promote the removal of these compounds.

Synergistic effects of economic benefits, resource conservation and carbon mitigation of kitchen waste recycling from the perspective of carbon neutrality

Kitchen waste, accounts for 40 %∼60 % of China's municipal solid waste, which recycles not only avoid waste of resources, but also reduces greenhouse gas emissions. Based on the survey data of Beijing municipal waste treatment plant, this study uses life cycle assessment to evaluate three kinds of kitchen waste treatment modes: aerobic composting, anaerobic digestion and anaerobic synergy. Then we analyze the technical feasibility, economic benefits and mitigation potential of three waste treatment modes. The anaerobic synergy has the highest technical feasibility and economic benefits. The total carbon emissions of different modes, through quantifying its emissions of collection, transportation, disposal and leakage, was aerobic composting > anaerobic digestion > anaerobic synergy. If all kitchen waste were treated with anaerobic synergy, cumulative carbon mitigation per person during 2025∼2060 was expected to 1019.2—1813.2 kg. Thus, recycling kitchen waste has a large mitigation potential to achieve China's carbon neutrality.

LED-irradiated photo-Fenton process on pollutant removal: outcomes, trends, and limitations.

This manuscript critically reviews the state of the art on the application of photo-Fenton processes irradiated by light-emitting diode arrays (LED) with a focus on the removal of contaminants of emerging concern (CEC) from aqueous matrices. LEDs are clean, low-cost radiation sources with longer lifespan compared to mercury lamps. This study covers the influence of LED sources, wavelengths, and dose upon CEC removal, and the potential for disinfection, abatement of antibiotic-resistant bacteria (ARB), and genes (ARG). The bibliographic search was performed in Scopus database using keyword combinations and resulted in a portfolio containing 52 relevant articles published between 2010-2023. According to reviewed papers, LED photoreactor design has evolved in the past decade aiming to improve CEC degradation in aqueous matrices while reducing construction and operation costs, and energy consumption. Among several reactors (annular, fluidized bed, parallel plate, wireless, pathway systems, and microreactor) surveyed for their performance and scalability, LED chips and strips are particularly suitable for application due to their wide emission angle (≈120°) and small size (mm2), which allow for, respectively, efficient illumination coverage and flexible arrangement and design. LED microreactors are very efficient in the degradation of contaminants and scalable with reduced area requirements. Although most studies were performed in synthetic solutions and at laboratory scale, the externally LED irradiated cylindrical reactor was successful for application in full-scale municipal water treatment plants. Future studies should focus on evaluating CEC removal in wastewater using scalable devices for continuous operation of solar photo-Fenton at night.

Bulking of activated sludge in the biological treatment of municipal and industrial wastewater, due to the massive development of filamentous bacteria Type 021N

A research of the causes and consequences of bulking of activated sludge was conducted at existing biological wastewater treatment plants (municipal and local at an industrial enterprise). The filamentous bacterium that was caused the bulking of the activated sludge in the studied treatment plants was identified as Type 021N. It was established that the studied filamentous bulking causes a significant deterioration of the technological characteristics of activated sludge flocs and it is accompanied by suppression of the nitrification process. To suppress the bulking of activated sludge two methods of suppressing the inflow of hydrogen sulfide into biological treatment plants were successfully used: blowing from wastewater at municipal treatment plants and inhibiting its formation at local treatment plants in the settling and laminar flow zones.

Optimizing Municipal Waste Collection: a Case Study of a City in Poland

The main problem of waste management is the increasing amount of municipal waste, and one of the key processes generating high costs is the waste collection process. The aim of the article was to optimize the route of a garbage truck using information technology (IT) software in one of the most populated Polish cities. The article tests the study hypothesis: the use of route optimization software will reduce the route length traveled by the garbage truck of the MZO in Pruszków. The data for the study was made available with the consent of the Municipal Treatment Plant in Pruszków. The received materials included information on, among others, Global Positioning System (GPS) readings of the garbage truck, including route start and end times, route length, average speed, driving time, and time of stops, points selected by the planners to collect waste along the route, information on the amount of waste collected during the implementation of the route, technical data on the moving vehicle and characteristics of the sorting plant were received. The article proposes the optimization of the routes of collection and transportation of municipal waste using the traveling salesman problem (TSP). The minimization of route length was assumed as the optimization criterion. All calculations were made in the Routimo program dedicated to route planning and optimization. As a result of the optimization, the route length was reduced by nearly 32%, and the working time by 9%. Thus, the research hypothesis stated in the article was positively verified.