Urban nitrogen budgets: flows and stock changes of potentially polluting nitrogen compounds in cities and their surroundings–a review

Concepts of material flow and mass consistency of nitrogen compounds have been used to elucidate nitrogen’s fate in an urban environment. While reactive nitrogen commonly is associated to agriculture and hence to large areas, here we have compiled scientific literature on nitrogen budget approaches in cities, following the central role cities have in anthropogenic activities generally. This included studies that specifically dealt with individual sectors as well as budgets covering all inputs and outputs to and from a city across all sectors and media. In the available data set, a clear focus on Asian cities was noted, making full use of limited information and thus enable to quantitatively describe a local pollution situation. Time series comparisons helped to identify trends, but comparison between cities was hampered by a lack of harmonized methodologies. Some standardization, or at least improved reference to relevant standardized data collection along international norms was considered helpful. Analysis of results available pointed to the following aspects that would reveal additional benchmarks for urban nitrogen budgets: analysing the share of nitrogen that is recycled or reused, separating largely independent sets of nitrogen flows specifically between food nitrogen streams and fossil fuel combustion-related flows, and estimating the stock changes for the whole domain or within individual pools

Reaction rate coefficient k

It was described the test of sewage sludge and organic fraction of municipal mixed solid waste thermal disintegration process. The waste activated sludge used during the tests was collected from the secondary settlement tank in a mechanical-biological wastewater treatment plant. The biowaste used in the studies was collected from an area of new buildings. It was noticed from means values of Soluble Chemical Oxygen Demand (SCOD) plot that both heating temperature and time, influence the amount of dissolved COD. The observations indicate that changes of SCOD can be described by an increasing, differentiable function of time and the rate of change of the soluble COD in the hydrolysates, in time is proportional to the difference of the maximum values of SCOD and its value in time, which leads to the relationship of the first-order ordinary differential equation. The process effectiveness depending on the temperature was described with the mathematical model including Van't Hoff-Arrhenius equation. Inspection of the data and some preliminary fits indicates, that for the description of changes in SCOD terms of time and temperature were adopted the form of nonlinear mixed model. Values of k20 indicator and Θ parameter depend on the substrate type. For waste activated sludge thermal disintegration, value of reaction speed indicator k20 was 0.028 h-1 (0,67 d-1), and value of temperature indicator equalled Θ = 1.024. For thermal disintegration of biological waste, value of reaction speed indicator k20 was 0.016 h-1 (0,38 d-1), and value of temperature indicator equalled Θ = 1.016

Biogas and Methane Potential of Pre-Thermally Disintegrated Bio-Waste

One of the environmental solutions employed in order to achieve circular economy goals is methane fermentation—a technology that is beneficial both for the stabilization and reduction of organic waste and for alternative energy generation. The article presents the results of research aimed at determining the biogas and methane potential of bio-waste which has been pre-thermally disintegrated, and determining the influence of variable process parameters of disintegration on the kinetics of fermentation. A first-order kinetic model was used to describe the fermentation as well as two mathematical models: logistic and Gompertz. It has been found that process parameters such as time (0.5, 1 and 2 h) and temperature (between 55 to 175 °C) have a significant effect on the solubilization efficiency of the bio-waste. The methane fermentation of thermally disintegrated bio-waste showed that the highest biogas potential is characterized by samples treated, respectively, for 0.5 h at 155 °C and for 2 h at 175 °C. The best match for the experimental data of biogas production from disintegrated substrates was demonstrated for the Gompertz model

Waste from rearing and slaughter of poultry – treat to the environment or feedstock for energy

Consumption of poultry has systematically grown for over 10 years. In 2007, Poland, with the participation of 11% dealt third place in Europe in the production of poultry meat with the input of 11% has taken the third place in Europe after France and the UK (about 14%). Intensification of poultry production on one hand provides to higher profitability, on the other hand generates more and more waste products, such as manure, slaughter wastes, dead birds, and the emission of gases (e.g. ammonia) into the environment. Management of waste in breeding and slaughter plants of poultry rarely complies with current regulations. This is connected with high costs of waste disposal hazardous to the environment, harmful and dangerous to human health. because of chemical composition and potential health risks. The article, based on literature data and our own research, characterizes the waste from rearing and slaughter of poultry and define the possible ways to negative impact on human health: directly by microbial infections or indirectly by emissions of ammonia to the atmosphere, the migration of pollutants into groundwater and surface water. Options of waste utilization in methane fermentation process have been presented. This technology reduces the risk of environmental hazard , while allowing for recovery renewable energy of biogas from biowaste. Waste from the turkey farm and slaughterhouse (the size of slaughterhouse about 26,000 units per week) were of mesophilic anaerobic digestion. Nine types of waste: turkey manure on straw, fresh straw used for bedding, heads, guts, feet and feathers were chosen. Flotation sediment, sewage from the slaughtering and chemical sludge was also fermented. High potential for methane from slaughterhouse waste (ca. 73%) and manure (63%), indicate for simultaneous disposal and energy recovery from methane fermentation process

The Influence of the Poles’ Lifestyle on the Quantity and Quality of Municipal Wastewater

The article presents lifestyle as an important factor determining the quantity and quality of municipal wastewater. The characteristic of wastewater in Poland has changed significantly in recent years. The qualitative characteristics of municipal wastewater indicate an increase of organic compounds and in the scope of micro-contaminants identified in them, e.g. nanoparticles, microplastics, pharmaceutical and personal care products or heavy metals. Therefore, the knowledge of parameters such as: BOD5, COD, total N, total P and suspension solids is no longer sufficient for the design and operation of wastewater treatment systems. Comprehensive research in this area is necessary to select those indicators that better describe the characteristics of wastewater

Temperature Impact of Nitrogen Transformation in Technological System: Vertical Flow Constructed Wetland and Polishing Pond

The article describes the results of the research, purpose of which was to evaluate influence of the temperature on the effectiveness of nitrification and denitrification in the sewage treatment system consisting of vertical flow constructed wetland and polishing pond. During the analysed period, the efficiency of removing total nitrogen was low and amounted to 12.7%. In the polishing pond in the summer period, content of total nitrogen in treated sewages was further decreased by nearly 50%. In the winter period, the polishing pond fulfilled mainly retention role and thus did not improve effectiveness of the whole system. Temperature coefficients, calculated on the basis of single first-order kinetics, for nitrification process in the filter bed (N-NH4+) and denitrification process in the polishing pond (N-NO3−) amounted to 1.039 and 1.089, respectively

Mathematical modelling of waste activated sludge thermal disintegration

Chemical Oxygen Demand (COD) solubilisation was used to evaluate the impact of thermal pretreatment on the transfer of sewage sludge from particulate to soluble phase. It was gathering the experimental data needed for building of empirical mathematical model describing the relation between applied temperature and time and rate of COD solubilisation and degradation. In view of repeated measurements, in order to describe the relationship between changes in the fraction of dissolved COD and the time and temperature, mixed models have been adopted where by fixed factor measurement conditions have been adopted: time and temperature, while the random factor changes the characteristics of waste activated sludge. Linear and logistic nonlinear mixed models were analyzed. The tests demonstrated that all variables are statistically significant in assessing their impact on the efficiency of liquefaction of sludge. On the basis of the estimated model, the temperature rise of 10°C increases degree of disintegration 1.7% above the average treatment time for 0.5h, by 2.6% for 1 hour, and by 3.9% for 2h. COD values decrease between 3 to 23% at temperatures in the range of 55 to 115°C. At higher temperatures COD was reduced in the range of 32 to 44%. Disintegration time did not have the significant impact on the degradation effect

Realization of National Programme of Municipal Wastewater Treatment and the quality of surface water in Poland

One of the aims of improving water quality, resulting directly from the Water Framework Directive 2000/60/EC, is to achieve in 2015, at least good status for all waters in the country. Following the adoption by Poland of the Water Framework Directive assessment of the economic and general cleanliness of water was replaced by an assessment of ecological status. In this way, the analysis of water status shall be treated as not only economic resources, but primarily as part of the ecosystem. The most important from the standpoint of human health protection, is the quality of water intended for human consumption.In the document „The purity of rivers based on the results of tests carried out within the national environmental monitoring in 2007–2009” is given that: – only 10.6% of the surface of flowing water meets the requirements of collective waters used for water supply for drinking, – up 28.7% of the length of monitored water is too polluted for them mildest demands posed conditioned needs of the economy. The decrease in water quality was affected by the physico-chemical pollutants such as pH, total suspension, manganese, polycyclic aromatic hydrocarbons (PAHs), CODCr, BOD5 and TOC. Large impact on reducing water quality category also had microbial contamination, the number of fecal coliform bacteria, fecal streptococci and total coliforms

Mathematical modelling of waste activated sludge thermal disintegration

Chemical Oxygen Demand (COD) solubilisation was used to evaluate the impact of thermal pretreatment on the transfer of sewage sludge from particulate to soluble phase. It was gathering the experimental data needed for building of empirical mathematical model describing the relation between applied temperature and time and rate of COD solubilisation and degradation. In view of repeated measurements, in order to describe the relationship between changes in the fraction of dissolved COD and the time and temperature, mixed models have been adopted where by fixed factor measurement conditions have been adopted: time and temperature, while the random factor changes the characteristics of waste activated sludge. Linear and logistic nonlinear mixed models were analyzed. The tests demonstrated that all variables are statistically significant in assessing their impact on the efficiency of liquefaction of sludge. On the basis of the estimated model, the temperature rise of 10°C increases degree of disintegration 1.7% above the average treatment time for 0.5h, by 2.6% for 1 hour, and by 3.9% for 2h. COD values decrease between 3 to 23% at temperatures in the range of 55 to 115°C. At higher temperatures COD was reduced in the range of 32 to 44%. Disintegration time did not have the significant impact on the degradation effect

Czysta energia z biogazu, słońca i zasobów geotermalnych drogą do niezależności energetycznej Oczyszczalni Ścieków w Gubinie

W ostatnich latach efektywność energetyczna w branży wodno-ściekowej zyskuje coraz bardziej na znaczeniu, ponieważ oczyszczalnie ścieków odpowiedzialne są za blisko 35% zużycia energii ze wszystkich obiektów komunalnych [1]. Odprowadzanie ścieków oczyszczonych do odbiorników zgodnie z obowiązującymi wymaganiami prawnymi wymusza stosowanie efektywnych technologii usuwania zanieczyszczeń i procesów przeróbki osadów ściekowych