Characterization of sewage screenings from wastewater treatment plants and upgrading via torrefaction.

The irregular occupation of the territory in Lagoa da Conceição, and the deficiencies on the wastewater management system, impacted negatively the trophic state of the coastal lagoon. After the wastewater overflow in Lagoa da Conceição’s Wastewater Treatment Plant (WWTP) the impact increased. The overflow manifested the need for an accurate quantification of the impacts caused by the WWTP. LCA (Life Cycle Assessment) it’s a recognized tool for quantifying environmental impacts caused by a product/system. Thus, this article aims to discuss the application of WWTPs through a critical review, establishing relations between the results found by these applications, and the use of LCA in Lagoa da Conceição’s case. 03 lines of discussion were identified on the articles review: the role of LCA in identifying critical spots and improvement opportunities in WWTPs, comparison between conventional and alternative infrastructures, and the life circularity on WWTPs.

Industrial wastewater discharged to a municipal sewage system may often be a source of valuable organic substrate for biological processes at a municipal wastewater treatment plant (WWTP). In such situations, the pre-treatment of wastewater at an industrial plant should be minimized, in order to maintain the favourable structure of organic material in influent to a WWTP. A frequent problem is how to determine the maximum industrial pollution load that can be discharged, without compromising the treatment capability of a WWTP. This article presents a method based on computer simulation that can be used for this purpose. As a result, the method produced the permissible industrial pollution load that could be discharged safely, and the relationship between chemical oxygen demand (COD) load and required biomass concentration as a function of process temperature. The method was tested at a fruit-processing plant and municipal WWTP, located in Poland. The results of this study have shown that the bioreactor should be operated at a biomass concentration varying between 3,600 and 5,400 g m−3 in function of the process temperature. Under such operational conditions, the WWTP would be able to accept the permissible industrial COD load of above 9,000 kg COD d−1 for a wide range of temperatures, namely 14–19 °C. If the WWTP was operated at a constant biomass concentration, its permissible industrial COD load would be reduced to 7,500–9,000 kg COD d−1. The method can be applied to other municipal WWTPs with activated sludge that receive industrial effluents.

Japfa Compeed Building is an office building managed by PT Ometraco Arya Samanta, has 7 floors and has just started operating and was inaugurated in January 2025. The building is located at Jalan Daan Mogot KM 12 No. 9, Cengkareng, West Jakarta. The building covers an area of approximately 29,272 m2. To ensure employee comfort, an effective clean water and wastewater management system is required, complying with the latest Indonesian National Standard, SNI 8153:2015. To meet the clean water needs of a population of 662, 39.72 m3 of clean water is required per day. The ground water tank capacity is 13.24 m3, while the roof water tank capacity is 2.92 m3. This office building has a Wastewater Treatment Plant (WWTP) with a water discharge capacity of 40 m3/day. Some of the wastewater is treated through a Wastewater Treatment Plant (WWTP), with a maximum capacity of 10 m3/day of recycled water. The water discharge savings generated from the WWTP reach 101 m3 per month, according to daily water discharge checks. The building also utilizes a Water Level Control (WLC) system for the distribution of clean and recycled water, enabling automatic water level control.

This study introduces a novel optimization approach, employing chance-constrained probabilistic-fuzzy uncertain programming, to enhance the efficiency of facultative ponds in wastewater management systems. Unlike traditional deterministic or stochastic models, this approach integrates both probabilistic and fuzzy uncertainties capturing real-world variations in Biological Oxygen Demand (BOD) degradation rates and wastewater loads. The model addresses the decision-making scenario where some uncertain parameters, like the rate of BOD reduction, are probabilistic with some probability density functions, and some other uncertain parameters, like wastewater load, are represented as fuzzy variables with membership functions determined by the decision-maker. Amid this uncertainty, the goal is to maximize the volume of wastewater treated while maintaining adequate safety margins via chance-based rules is implemented to the objective and the constraints. Using the layout of the Bantul residential wastewater treatment plant located in Yogyakarta, Indonesia, this research succeeded in determining optimal decisions regarding processing time and wastewater flow rate. Consequently, it is inferred that the developed model effectively resolves the problem at hand, rendering it applicable for decision-makers in similar contexts.

A comparative study on decomposition of cellulose between supercritical water (400°C, 40 MPa) and subcritical water (280°C, 40 MPa) treatments was made to elucidate the difference in their decomposition behavior. Consequently, the supercritical water treatment was found to be more suitable for obtaining high yields of hydrolyzed products. However, cellulose was found to be more liable to fragment under supercritical water treatment, resulting in a decrease in the yield of hydrolyzed products. On the contrary, cellulose was found to be liable to more dehydration in the subcritical water treatment. Based on these results, we have proposed the combined process of short supercritical water treatment followed by subcritical water treatment so as to inhibit fragmentation. Consequently, this combined treatment was able to effectively control the reaction condition, and to increase the yield of hydrolyzed products.

Sioux City wastewater treatment plant (WWTP) has experienced filamentous bacterial growth in their secondary clarifiers. The filamentous bacteria create bulking sludge, which causes solids to remain in suspension, thereby creating high solids discharge in the WWTP effluent. Iowa State University (ISU) was contracted to conduct a three-phase study to investigate the WWTP operational problems. Phase I was a paper study that examined the causes of high volatile fatty acid (VFA) loading into the WWTP. Phase II characterized four selected industrial wastewaters in order to determine appropriate wastewater pretreatment techniques. Phase III involved the aerobic biological pretreatment of the four industrial wastewaters in laboratory-scale bioreactors to remove VFAs. Phase II and III are evaluated in this report. The four industrial wastewaters selected were Feed Energy, which produces acid oil that is used as a livestock ingredient; Darling, which is a rendering facility; Menu Food manufactures pet food; and John Morrell, a hog slaughtering facility that manufactures pork products, in Phase II, industrial wastewater samples were characterized based on VFA, soluble chemical oxygen demand (SCOD), biochemical oxygen demand (BOD), and volatile suspended solids (VSS) concentrations. Wastewater pretreatment recommendations were given to Sioux City WWTP and the WWTP decided that aerobic biological pretreatment should be tested for all four selected industries in Phase III. The Phase III results showed that the Feed Energy wastewater was not successfully pretreated aerobically to remove VFAs with HRTs ranging from 3 hours to 6 days. The Darling condensate wastewater achieved VFA removals of 43 to 74% with HRTs ranging from 12 to 48 hours and a 95% VFA removal was possible at an 18-hour HRT with phosphorus supplementation. VFA removals of 55% and 63% were achieved for the Menu Food wastewater with HRTs of 4.5 and 9-hours. The John Morrell blood stick wastewater achieved VFA removals ranging from 25 to 71% with HRTs ranging from 12 to 24 hours.

The management and disposal of the sewage sludge (SS) generated by a wastewater treatment plant (WWTP) as part of the municipal wastewater (MWW) treatment process is one of the main socio-environmental issues faced by this type of system. Taxco de Alarcón, Guerrero, in southern Mexico has had a WWTP operating since 2016, and the SS disposal is a task that must be addressed by the WWTP. Thus, the aim of this work was to evaluate the growth capacity of Panicum maximum, also known as mombaza grass (MG), by using SS generated within the "Taxco de Alarcón wastewater treatment plant" as substrate. To do so, 4 g of MG seeds were scattered over 5 kg (dry basis) of SS. As a control, a commercial compost soil was used, hereafter called pattern soil (PS). The experiment was carried out in triplicates for three months and drinking water (water used for human consumption) was used for crop irrigation. Each month a MG harvest was carried out. The response variables analyzed for MG were germination time (one month after plant emergence), height (HMG), growth rate GrMG, and yield (YMG), whereas in the SS and PS the content of organic matter was analyzed. Furthermore, the chemical composition was analyzed using scanning electron microscopy and X-ray energy dispersion spectroscopy (SEM-EDS) on the MG, SS, and PS. The results showed that MG germinated faster on PS (5 days) than germination on SS (7 days). However, the MG grown on SS reached a considerably higher height (45 cm) compared to the height reached on PS (17 cm). Furthermore, the maximum GrMG over SS was also higher than the maximum GrMG observed on the PS, 3.64 and 1.40 cm∙day-1, respectively. In terms of YMG, it was observed that on SS it reached an average monthly YMG of 416 g∙m-2, whereas in PS it reached a YMG of 72 g∙m-2. The chemical analysis detected P, K, Ca, Mg, and S, considered macronutrients in both substrates. Besides, some micronutrients identified in SS were Cu, Fe, Mn, and Zn, whereas in PS it was also possible to detect micronutrients except Mn and Zn. All the macronutrients detected in the substrates were observed in the harvested MG. However, in the MG harvested in PS, Mn and Zn were not detected. Hence, a feasible disposal strategy for the SS generated by the Taxco de Alarcón WWTP is as a substrate for grass forage MG by its high organic matter content, the significant presence of macro and micronutrients, and the performance shown by MG cultivated in SS. Furthermore, the SS characteristics provide added value and can be considered as organic amendments of agricultural soils.

Self-sustaining smoldering combustion is a promising technology for treating sewage sludge from wastewater treatment plants because of its low energy inputs. Proper use or disposal of the resulting ashes requires thorough characterization of their properties, including the content of total organic carbon (TOC). Here, we develop a two-step method for quantifying TOC in the raw ashes from sewage sludge smoldering combustion. The first step is to thermally treat the raw ashes at 500 °C in N2 for 1 h, followed by ultimate analysis of both the raw ashes and the thermally treated ashes. This enables the quantification of carbon released during thermal treatment. The second step is nonisothermal thermogravimetric analysis (TGA) of the thermally treated ashes, in which the samples are heated to 900 °C at 10 °C/min in air. The weight losses at 310–500 °C are confirmed to be caused by organic carbon oxidation, allowing us to determine the contents of carbon retained in the thermally treated ashes. The sums of these two portions of carbon represent the contents of TOC in the raw ashes, which are ∼0.85–6.52 wt % (dry basis), depending on their locations and particle sizes. The two-step (thermal treatment–TGA) method is validated via a method that includes acid washing of the thermally treated ashes, ultimate analysis of the acid-washed ashes, and TOC analysis of the leachates. The two-step method is simple and accurate and, importantly, provides thorough information on the thermal behavior of the raw and thermally treated ashes.

Operational factors affecting enhanced biological phosphorus removal at the waste water treatment plant in Helsingborg, Sweden

Enhanced biological phosphorus removal (EBPR) has since 1992 been run as a full-scale UCT-process in a part of the waste water treatment plant in Helsingborg. Between June 1993 and July 1994 an extended operational and microbiological investigation was conducted. It was shown that the major phosphorus removal mechanism was biological and that at the most 10% of the soluble phosphorus entering the biological reactor, was removed due to chemical reactions. The VFA-potential in pre-treated waste water has been found to be a key factor. At the waste water treatment plant in Helsingborg 1 mg phosphorus is removed for each 14 mg VFA-potential added. COD, soluble COD and BOD1 are correlated to the VFA-potential, which means that these measurements can be used as operational parameters. If enough VFA-potential is present, the concentration of soluble phosphorus will be lower than 0.3 mg/l in the effluent even at temperatures below 10°C. The mean concentration of soluble phosphorus in the effluent has been 0.29 mg/l during the period October 1993-July 1994. Effluent nitrogen concentration was during the evaluation period between 8–10 mg/l and it was found that PHA was one of the major carbon sources for denitrification. Compared with a pre-denitrification process in combination with simultaneous precipitation, both the filament index and the DSVI were lower in the EBPR process. Other operational factors that affect the process are oxygen and nitrate concentrations in flows to the anaerobic reactor and the degree of internal recirculation from the aerobic to the anoxic reactor.

Constructed wetlands are cost-effective wastewater treatment alternatives that receive worldwide acceptance. For the Kenyan hospitality industry, in particular, constructed wetlands (CWs) provide opportunities for wastewater reuse and recovery of resources, as well as improvements in local environmental conditions. Hospitality establishments produce large volumes of wastewater that is sometimes discharged to the environment without being treated. This is not only harmful to communities living downstream of these rivers but also to the flora and fauna which are the main attraction for most who visit these lodges. This study used qualitative methods to collect and analyze published official government documents, peer-reviewed research articles, and professional reports including leading international and Kenyan case studies to explore how constructed wetlands can be effectively used in game lodges and resorts situated in arid and remote areas of Kenya. The study investigated wastewater management systems adopted by remote game lodges and resorts in Kenya and the potential role, as well as the challenges to adopting constructed wetland (CW) technology. The results indicated that hotels, game lodges, and resorts both internationally and locally are adopting different types of CWs including surface and subsurface flow as alternative nature-oriented wastewater management systems. The study identified opportunities in the use of CWs as a wastewater management and conservation strategy. The results suggest that there are potential challenges which include inadequate expertise and technical support; low volume of discharge during off-seasons; limited space or land; and the attitude of hospitality managers towards constructed wetlands. Based on these preliminary findings, one may conclude that game lodges, ecolodges, and resorts in remote areas are prime candidates for constructed wetland establishment. The study makes specific recommendations with implications for policy and practice to promote sustainable hospitality operations and environmental conservation. It is suggested that future studies test the efficacy and efficiency of CW technology as wastewater management systems in the Kenyan wilderness areas including national parks, game reserves, and forests.

In this thesis, experimental results and their analysis are presented on the phase transformations of microcrystalline cellulose (MCC) under two different treatments. First, MCC was subjected to ball milling in air for different times tBMi = 5, 10, 15, 30, 45, 60 and 120 minutes. Second, phase transformation of MCC under hydrothermal treatment (HTT) in distilled water using an autoclave was investigated by varying the pressure P, temperature T for different time tau. Both of the post treated samples were analyzed by X-Ray Diffraction (XRD), Fourier Transform Infrared (FTIR) Spectroscopy, surface area measurements, Scanning Electron Microscopy (SEM) and Thermo-gravimetric Analysis (TGA).;Experimental results on the structural changes observed in microcrystalline cellulose subjected to ball milling for upto 120 minutes are reported. Under ball milling, the Segal crystallinity XCR systematically decreases with increase in ball milling time tBM with the largest rate of decrease observed for the initial time tBM< 30 minutes. These results show transformation of crystalline cellulose to an amorphous cellulose phase. The results on the XRD above tBM> 30 minutes are inconclusive to prove the presence of cellulose. Therefore evidence about the presence of cellulose above t BM> 30 minutes is shown by analyzing the results from FTIR spectroscopy.;Under hydrothermal treatment in water using an autoclave in which pressure P, temperature T and time of treatment tau were varied, the cellulose structure was observed to completely breakdown at the minimum conditions of P &ap; 400 PSI, T . 230°C and tau &ap; 30 minutes. Analysis of the XRD patterns yields information only about conversion of crystalline to amorphous form and the presence of cellulose is still vague. Results of the FTIR spectroscopy shows that for higher P, T and tau, the cellulose structure has completely broken-down resulting in new chemical phases. This different chemical nature of the converted sample is also evident from its thermal behavior under TGA as compared to that of unconverted sample.

The Guheshwori Wastewater Treatment Plant (GWTP) was used for the study work. The main objective of the research work was to analyze the economic benefits of sludge and water effluent management of the Wastewater Treatment Plant (WWTP). The Cost Benefit Analysis methodology was used and analyzed to meet the research objectives. The Wastewater treatment plant has significant environmental benefits as well as monetary values that can be generated from water effluent, sludge effluent, and plant visit fares, which indicates the revenue generation from the wastewater treatment plant. This study takes a ground-breaking strategy to economically value wastewater treatment in Nepal. A helpful indication of the viability of wastewater treatment will be the comparison of the benefits of WWTP with the operating costs of the treatment process. On a dry mass basis, the finished sludge had a total nitrogen content of 3.58 percent, a total phosphorus content of 1.54 percent, and a potassium content of 0.15 percent. After pathogen reduction sludge can be used in agricultural fields as fertilizer leading to high monetary values for GWTP. Plant visit fares from the visitors also can generate monetary value. Similarly, water effluent can be used in watering the parks, irrigation, and cleaning, and after turbidity reduction can be used in concreting and curing. The Guheshwori Waste Water Treatment Plant requires a yearly total of around NRs. 4,49,94,639 to operate. If we merely sale 5% of the treated water NRs. 94,03,130, 10% of the treated water NRs. 1,88,08,085, 50% of the treated water NRs. 9,40,28,380, and 100% of the treated water NRs. 18,80,61,870 can be generated. From the GWTP wastewater treatment plant's sludge, 57,34,202 may be produced yearly. There is a potential income generation of about NRs. 12,02,500 from the plant visit fares. To close these disparities, Government of Nepal (GoN) must enact legislation on the optimal use of WWTP effluent, the protection of water sources, public health, and environmental economics. The welfare concept of economics concept states the maximum utilization of the reuse of the resources of the effluents from the Guheshwori Wastewater Treatment Plant, NBV&gt;1 can be achieved from an environmental economics viewpoint alongside achieving Sustainable Development Goals SDGs Goals 6, 8, and 11.

Aim: To determine economic and environmental impacts of greenhouse gas harvesting from bio-waste generated at wastewater treatment plant. Study Design: Quantitative experimental research for anaerobic digestion using a prototype bio digester. Place and Duration of Study: Case study of Kaunda square wastewater treatment plant in Lusaka city of Zambia. The duration of study was one year inclusive of research proposal writing. Methodology: Two Anaerobic Digestion (AD) experiments were conducted; alongside was control experiment-c. The first experiment-a used a balloon as means of biogas collection while experiment-b used water displacement technique. Each experiment used 9.6kg feedstock (on dry basis) into a 40 litres prototype bio digester and subjected to AD for 30days hydraulic retention time (HRT). Results: Total biomass potential available as feedstock at kaunda square wastewater treatment ponds was found to be 483,947kg per annum. The 9.6kg biomass feedstock used in experiments A and B produced 0.0179 and 0.0165 of biogas respectively leading to 0.0172 as average monthly biogas production. Scaling-up these experimental findings of using 9.6kg feedstock to produce 0.0172 biogas, resulted in Kaunda square wastewater treatment plant with feedstock potential of 483,947kg yielding 868.43Kg (755,156.78 liters) of biogas production per annum. Total amount of greenhouse gases (GHGs) of environmental importance came from the summation of contributions of methane and carbon dioxide and expressed as carbon-dioxide equivalents . The value of the two GHGs was found to be with direct effect on global warming and climate change while the digestate had its economic value in agricultural use where the potential stood at 9,662 by 50kg bags of nitrogen/sulphur rich organic fertilizer per annum. Conclusion: Energy harvesting through harvesting of greenhouse gases from bio-waste can lead to reduction in emission of greenhouse gases, reduce energy deficit and improve food security through soil preservation.

This study presents a comparative analysis of the environmental and economic performances of four integrated waste and wastewater management scenarios in the city of Aarhus in Denmark. The purpose of this analysis is to deliver decision support regarding whether (i) the installation of food waste disposers in private homes (AS1) or (ii) separate collection and transport of organic waste to biogas plants is a more viable environmental and economic solution (AS2). Higher environmental benefits, e.g., mitigation of human health impacts and climate change, are obtained by transforming the existing waste combustion system into scenario (ii). Trade-offs in terms of increased marine eutrophication and terrestrial ecotoxicity result from moving up the waste hierarchy; i.e., from waste incineration to biogas production at wastewater treatment plants with anaerobic sludge digestion. Scenario (i) performs with lower energy efficiency compared to scenario (ii). Furthermore, when considering the uncertainty in the extra damage cost to the sewer system that may be associated to the installation of food waste disposers, scenario (ii) is the most flexible, robust, and less risky economic solution. From an economic, environmental, and resource efficiency point of view, separate collection and transport of biowaste to biogas plants is the most sustainable solution.