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This study analyzed the effect of lightweight aggregates made of fly ash from sewage-sludge thermal treatment (FASSTT LWA) on the effectiveness of phosphorus removal from wastewater in vertical constructed wetlands (CWs), depending on FASSTT LWA content in the CW filling and hydraulic loading rate. It was performed over 13 weeks using 15 lysimeters prepared as double-layer systems. An upper layer was made of FASSTT LWA above the gravel layer with different thicknesses of FASSTT LWA (CW 0 cm: only gravel; CW 12 cm, CW 25 cm; CW 50 cm, and CW 100 cm: only FASSTT LWA). Each filling variant was repeated three times. Wastewater with a mean phosphorus concentration of 7.43 mgP/L was fed to the lysimeters once a day. The hydraulic loading rates tested were 3.0, 5.0, and 7.0 mm/d. Both the increased FASSTT LWA content in the CW filling and the decreasing hydraulic loading rate were found to boost the effectiveness of phosphorus removal in the treated wastewater. Constructed wetland filled in 100 % with FASSTT LWA ensured a reduction in phosphorus concentration below 2.0 mg P/L at all hydraulic loading rates tested.

This study aimed to evaluate operation technology and functioning of facilities for the treatment of municipal sewage in a small wastewater treatment plant operating based on the trickling biofilters technology, in the winter (February) and summer (June-July) periods. Additional analyses were conducted to determine the effectiveness of contaminants removal in particular facilities of the technological system tested. Study results indicate that the sewage treatment plant operating based on the trickling biofilters technology ensures effective removal of organic compounds, total nitrogen, total phosphorus, and total suspended solids. In the summer period, the effectiveness of contaminants removal reached 92%, 52.9%, 97.9%, and 99.9%, respectively, whereas in the winter season it was lower an reached 69.5%, 12.4, 93.0, and 95.0%, respectively. Treatment effectiveness achieved in this study was referred to results of investigations conducted in the same sewage treatment plant 24 years ago. Results obtained may provide a valuable guideline to designers and operators of small sewage treatment plants.

This paper presents the results of a study on the possibility of applying various configured filters filled with a mixture of Rockfos® and Leca® material for the effective capture of phosphate from domestic wastewater. The tests were carried out for two years at two wastewater flow rates (20 and 40 L/day) in three pairs of filtration columns with a volume of filter material equal to 20 L each. Columns 1A and 1B were filled only with Rockfos®. Columns 2A and 2B contained Rockfos® and two 5-cm layers of Leca®. Columns 3A and 3B were filled with Rockfos® and a 10% addition of Leca®. A high phosphate removal efficiency was obtained at a level of 93.2–94.9% for all columns tested at a flow rate of 20 L/day with a retention time of 12 h. After 250 days of the experiment, the efficiency of phosphate removal decreased significantly, which was associated with a drop in the temperature of the inflowing wastewater (3 Rockfos® with the addition of Leca® in 1 m3/day of wastewater inflow.

This manuscript presents results of a study on sorption effectiveness of orthophosphate and nitrate III and V in an equimolar mixture of P–PO 4 , N–NO 2 and N–NO 3 using chitosan in the form of hydrogel beads. Analyses were carried out for: the effect of pH on sorption intensity of orthophosphate and of nitrate III and V onto chitosan, sorption kinetics onto chitosan, and the maximum sorption capacity of P–PO 4 , N–NO 2 and N–NO 3 by chitosan in a mixture. The most effective sorption of P–PO 4 , N–NO 2 and N–NO 3 was observed at pH 4. In turn, at pH 6–11 the sorption of orthophosphate and nitrate onto chitosan proved ineffective. P–PO 4 , N–NO 2 and N–NO 3 sorption kinetics was best described by the pseudo-second order model. The model of intraparticle diffusion fitting to experimental data demonstrated that the process of orthophosphate and nitrate sorption onto chitosan proceeded in 2 phases, i.e. 1 – adsorption and 2 – absorption. A phenomenon of the partial release of P–PO 4 , N–NO 2 and N–NO 3 after a specified period of time was observed in the study, which was due to a change in solution pH induced by the sorbent. The period after which desorption occurred was 120 min in the case of phosphates and 60 min in the case of nitrates III and V. The quantity of bound sorbate (a mixture of orthophosphate and nitrate) was the highest in the 60th minute of sorption. The study demonstrated evident competition between H 2 PO 4 − , NO 2 − and NO 3 − ions. The affinity of orthophosphate and nitrate to the sorption centers of chitosan could be ordered as follows: P – PO 4 > N – NO 2 > N – NO 3 . Sorption equilibrium isotherms were best described by a heterogeneous Langmuir’s model. In the equimolar mixture of P–PO 4 , N–NO 2 and N–NO 3 , the sorption capacity of 1 g of chitosan reached 0.507 mmol H 2 PO 4 − /g, 0.373 mmol NO 2 − /g and 0.350 mmol NO 3 − /g, which means a total of 1.23 mmol nutrients.

Large volumes of pavement de-icing and anti-icing fluids, collectively termed de-icing agents, are used at airports to facilitate wintertime safe air travel. After use, most of the them get typically mixed with storm water runoff and may enter soil and waters near the airports. Wastewater resulting from airports&rsquo, winter operations is contaminated mainly with nitrogen and carbon compounds. Previous research results have shown that the use of biofilters filled with lightweight aggregates prepared from fly ash from sewage sludge thermal treatment (FASST LWA) could be an effective method for removing nitrogen and organic compounds at low temperatures, i.e., 0&ndash, 8 &deg, C. For this to be possible, it is necessary to maintain a proper ratio between the amounts of carbon and nitrogen in the treated wastewater, through the simultaneous application of de-icing agents containing urea and carbon compounds. Biofilter technology is part of the concept of sustainable development. Their filling is made of waste materials and one of the pollutants (organic compounds) present in the wastewater is used to remove other pollutants (nitrogen compounds). In this study, technological systems for the treatment of wastewater containing airport runway de-icing agents with biofilters were proposed, which allow for the treated wastewater to be discharged into natural waters, soil, and sewerage network.

The influence of the degree of deacetylation of chitosan from the range of DD = 75–90% on the effectiveness of sorption of nitrates from aqueous solutions was investigated. The scope of the research included: determining the effect of pH on the effectiveness of N-NO3 binding on chitosan sorbents and determining the sorption capacity of chitosan sorbents with different degrees of deacetylation after 5, 15, 30 and 60 minutes. The effectiveness of sorption of nitrates on chitosan sorbents increased in the series DD=75% < DD=85% < DD=90%. Regardless of the degree of deacetylation, the sorption effectiveness of nitrates on chitosan was the highest at pH 4. The amount of nitrate-related sorbents was the highest after 30 min of sorption. A process time which was too long resulted in desorption of nitrates. The maximum sorption capacity for chitosan with the degree of deacetylation DD = 75, 85 and 90% was 0.59 mg N-NO3/g, 0.60 mg N-NO3/g and 0.87 mg N-NO3/g, respectively.

This study investigates the feasibility of using an organic substrate in the form of acetic acid to enable wastewater denitrification in a Sequencing Batch Biofilm Reactor (SBBR). The impact of nitrates presence on the yield of biological dephosphatation were determined as well. The experiment included 296 cycles and was divided into 4 series differing in the load of nitrates. Ratio N:(C and P) was: 7:(140 and 7); 35:(140 and 7); 70:(140 and 7) and 140:(140 and 7). Hydraulic retention time in the reactor was 12h (6h mixing – dissolved oxygen concentration below 0,1 and 6h aeration – concentration of dissolved oxygen 3.0±0.8 mgO2•dm-3). Study demonstrated that the 30-day adaptation period (60 cycles) was sufficient for the development of a stable biofilm. The C:N ratio of 2 ensured total nitrogen concentration in the effluent below 1 mgN•dm-3. Mean efficiency of biological dephosphatation reached 7.0, 17.4, 18.7, and 30.3% in series 1-4, respectively. In the case of series 2 and 3, no significant differences were demonstrated in total phosphorus concentration in the effluent. In the other series, the differences turned out to be significant.

In this study, we determined the effectiveness of removal of nutrients (nitrates and orthophosphates) from greenhouse wastewaters (GW) using non-cross-linked chitosan (CHs) and chitosan cross-linked with epichlorohydrin (CHs-ECH) in the form of hydrogel beads. GW used in the study had the following parameters: N-NO3 621.1 mg/L, P-PO4 60.8 mg/L, SO42− 605.0 mg/L, Cl− 0.9 mg/L, Ca2+ 545.0 mg/L, Mg2+ 178.0 mg/L, K+ 482.0 mg/L, hardness 113° dH, and pH 6.2. The scope of the study included determination of the effect of pH on wastewater composition and effectiveness of nutrient sorption, analyses of nutrient sorption kinetics, and analyses of the effect of sorbent dose on percentage removal of nutrients from GW. CHs-ECH was able to sorb 79.4% of P-PO4 and 76.7% of N-NO3 from GW, whereas CHs to remove 92.8% of P-PO4 and 53.2% of N-NO3. Electronic supplementary material The online version of this article (10.1007/s11356-018-2078-z) contains supplementary material, which is available to authorized users.

The annual global production of milk is approximately 630,000 million litres and the volume of generated dairy wastewater accounts for 3.2 m3·m−3 product. Dairy wastewater is characterized by a high load of chemical oxygen demand (COD). In many wastewater plants dairy wastewater and municipal wastewater are co-treated. The effect of dairy wastewater contribution on COD fraction changes in municipal sewage which has been treated with a sequencing batch reactor (SBR) in three wastewater treatment plants in north-east Poland is presented. In these plants the real contribution of dairy wastewater was 10, 13 and 17%. In raw wastewater, SS fraction (readily biodegradable dissolved organic matter) was dominant and ranged from 38.3 to 62.6%. In the effluent, SS fraction was not noted, which is indicative of consumption by microorganisms. The presence of dairy wastewater in municipal sewage does not cause changes in the content of the XI fraction (insoluble fractions of non-biodegradable organic matter). SBR effluents were dominated by non-biodegradable dissolved organic matter SI, which from 57.7 to 61.7%. In raw wastewater SI ranged from 1.0 to 4.6%. Xs fraction (slowly biodegradable non-soluble organic matter) in raw wastewater ranged from 24.6 to 45.5% while in treated wastewater it ranged from 28.6 to 30.8%. In the control object (fourth wastewater plant) which does not process dairy wastewater, the SS, SI, Xs and XI fraction in inflow was 28.7, 2.4, 51.7 and 17.2% respectively. In the effluent the SS, SI, Xs and XI fraction was below 0.1, 33.6, 50.0 and 16.4% respectively.

A hydrogel chitosan sorbent ionically cross-linked with sodium citrate and covalently cross-linked with epichlorohydrin was used to remove nutrients from an equimolar mixture of P-PO4, N-NO2 and N-NO3. The scope of the study included, among other things, determination of the influence of pH on nutrient sorption effectiveness, nutrient sorption kinetics as well as determination of the maximum sorption capacity of cross-linked chitosan sorbents regarding P-PO4 (H2PO4-, HPO42-), N-NO2 (HNO2, NO2-), and N-NO3 (NO3-). The effect of the type of the cross-linking agent on the affinity of the modified chitosan to each nutrient was studied as well. The kinetics of nutrient sorption on the tested chitosan sorbents was best described with the pseudo-second order model. The model of intramolecular diffusion showed that P-PO4, N-NO2 and N-NO3 sorption on cross-linked hydrogel chitosan beads proceeded in two phases. The best sorbent of nutrients turned out to be chitosan cross-linked covalently with epichlorohydrin; with P-PO4, N-NO2 and N-NO3 sorption capacity reaching: 1.23, 0.94 and 0.76mmol/g, respectively (total of 2.92mmol/g). For comparison, the sorption capacity of chitosan cross-linked ionically with sodium citrate was: 0.43, 0.39 and 0.39mmol/g for P-PO4, N-NO2 and N-NO3, respectively (total of 1.21mmol/g).

This study compared properties of hydrogel chitosan sorbents crosslinked with eight agents, including four ionic ones: sodium citrate, sodium tripolyphosphate, sulfosuccinic acid, and oxalic acid and four covalent ones: glutaraldehyde, epichlorohydrin, trimethylpropane triglycidyl ether, and ethylene glycol diglycidyl ether. The effect of crosslinking process conditions (pH, temperature) and dose of the crosslinking agent on chitosan sorbent stability during sorption and on the effectiveness of Reactive Black 5 dye sorption were examined. The optimal parameters of crosslinking ensuring sorbent stability in acidic solutions and high sorption capability were established for each crosslinking agent tested. The susceptibility of crosslinked sorbents to mechanical damages was analyzed as well. The process of ionic crosslinking was the most effective at the pH value below which hydrogel chitosan sorbent began to dissolve (pH 4). The crosslinking temperature ranging from 25 to 60 °C had no effect upon sorbent stability. The higher temperature during ionic crosslinking, however, slightly decreased RB5 sorption effectiveness. The ionic crosslinking significantly decrease the susceptibility of chitosan hydrogels to mechanical damages. In the case of covalent crosslinking of chitosan hydrogel beads, the effect of process conditions (pH, temperature) on the properties of the crosslinked sorbent depended on the type of crosslinking agent. The sorbents crosslinked with covalent agents were usually harder but also more fragile, and therefore more susceptible to mechanical damages.

The study demonstrated that citric acid, as an organic carbon source, can improve denitrification in Anaerobic Sequencing Batch Biofilm Reactor (AnSBBR). The consumption rate of the organic substrate and the denitrification rate were lower during the period of the reactor's acclimatization (cycles 1–60; 71.5 mgCOD L−1 h−1 and 17.81 mgN L−1 h−1, respectively) than under the steady state conditions (cycles 61–180; 143.8 mgCOD L−1 h−1 and 24.38 mgN L−1 h−1). The biomass yield coefficient reached 0.04 ± 0.02 mgTSS· mgCODre−1 (0.22 ± 0.09 mgTSS mgNre−1). Observations revealed the diversified microbiological ecology of the denitrifying bacteria. Citric acid was used mainly by bacteria representing the Trichoccocus genus, which represented above 40% of the sample during the first phase of the process (cycles 1–60). In the second phase (cycles 61–180) the microorganisms the genera that consumed the acetate and formate, as the result of citric acid decomposition were Propionibacterium (5.74%), Agrobacterium (5.23%), Flavobacterium (1.32%), Sphaerotilus (1.35%), Erysipelothrix (1.08%).

The study was conducted in a one-stage rotating electrobiological disk contactor (REBDC) and a rotating electrochemical disk contactor (RECDC). Synthetic wastewater with characteristics similar to the wastewater from soil-less cultivation of tomatoes was used in the experiment. Current efficiency (CE) values, that express the denitrification performance of bio- and electrochemical reactors, were higher in the electrobiological contactor than in the electrochemical one. Combining biological processes with electrochemical processes in the electrobiological contactor resulted in almost 20% higher current efficiency in the contactor operated at a density of 0.63 A/m2 and hydraulic retention time (HRT) = 4 h. The study showed that, in both the electrochemical and the electrobiological contactor, current density increase and hydraulic retention time extension increased electric power consumption (E) during phosphorus compounds removal and simultaneously lowered current efficiency.

Soilless plantations under cover constitute a significant part of horticulture. This study aimed at determining the qualitative composition of wastewater generated from the soilless cultivation of tomato under cover. This is important for managing the wastewater, which may be recirculated to allow the or employ a partial or complete recovery of minerals. Two plantations located in north-eastern Poland, which differed in the type of substratum (coconut fiber or rockwool), were studied. The generated wastewater was characterized by a low content of organic matter and a high concentration of total nitrogen (TN), total phosphorus (TP), and salinity (EC). Over 99% of the TN was constituted by nitrates. The chemical oxygen demand (COD) changed from 50.07 to 75.82 mgO2&middot, L&minus, 1 (greenhouse 1), and from 37.35 to 78.12 mgO2&middot, 1 (greenhouse 2), the content of TN changed from 403.59 to 614.89 mgN&middot, 1 (greenhouse 1), and from 270.00 to 577.40 mgN&middot, that of TP changed from 35.44 to 78.00 mgP&middot, 1 (greenhouse 1), and from 54.10 to 104.00 mgP&middot, and the EC changed from 3.53 to 6.93 mS&middot, cm&minus, 1 (greenhouse 1), and from 4.94 to 6.94 mS&middot, 1 (greenhouse 2). No statistically significant correlations were noted between TN and TP, or between TP and EC.

There is a growing global environmental problem of agricultural wastewater from soilless plant cultivation systems. In most countries dominate open fertilization systems, in which excess of nutrient solution is discharged in an uncontrolled way into the ground inside greenhouses or adjacent areas. Wastewater from such systems is characterized by a very high concentration of nitrogen and phosphorus compounds and their discharge into the environment causes significant pollution of the water and soil environment. The goal of the research was to determine the contribution of electrochemical reduction of nitrogen, hydrogenotrophic and heterotrophic denitrification in the process of nitrogen removal in a rotating electrobiological contactor (REBC) depending on hydraulic retention time (HRT) and electric current density (J). Synthetic sewage with characteristics corresponding to wastewater from soilless cultivation of tomatoes was the subject of the research. The first part of the experiment included determination of the effect of HRT on the effectiveness of bio-processes of nutrients removal in a rotating biological contactor (RBC). The second concerned the effect of HRT and J on the effectiveness of nutrients removal in a rotating electrochemical contactor (RECC), while the third part - the effect of HRT and J on the effectiveness of nutrients removal in REBC. RBC was characterized by low efficiency of denitrification (6.2 to 9.2%). The effectiveness of nitrogen removal in RECC was determined by both electric current density and hydraulic retention time. The highest efficiency was 53.4%. REBC nitrogen removal effectiveness was higher than in RBC and in RECC. The nitrogen removal efficiency increased along with increasing values of HRT, reaching the maximum value of 68.6% for J=10.0A/m2 and HRT=24h. The contribution of hydrogenotrophic denitrification in total nitrogen removal increased with the increase of electric current density.

The basic factors determining the efficiency of the removal of nitrogen and carbon compounds from airport wastewater containing de-icing agents are low temperature and the C/N ratio (carbon to nitrogen ratio). Biofilm reactors (biofilters) create better conditions for nitrification and denitrification than suspended biomass reactors. The scope of the study included determination of the influence of the C/N ratio in the wastewater on nitrification, denitrification and organic compound removal in biofilm reactors depending on the temperature. The experiment was performed in 24 circular laboratory biofilters with LECA (Light Expanded Clay Aggregates) filling. The study was divided into three series differing in organic carbon loading. In each series, carried out at the same hydraulic retention time, biofilters were operated at 25, 8, 4 or 0 &deg, C. The study showed the effective removal of nitrogen compounds across a very wide temperature range. The applied filling and properly selected operating parameters of the reactors resulted in effective simultaneous nitrification and denitrification. The highest efficiency of nitrogen removal at 0 &deg, C (34.57 &plusmn, 4.54%) was obtained at the C/N ratio of 0.5 gC/gN. The efficiency of denitrification (the lowest at the temperature of 0 &deg, C) increased as the temperature and C/N ratio increased in the wastewater.

The goal of research was to examine waste beer as a source of carbon in an anaerobic sequencing batch biofilm reactor (AnSBBR). It was demonstrated that waste beer enhanced denitrification. Observed biomass yield coefficient ( Y obs ) was one size of magnitude lower than for suspended-biomass reactors (0.03 ± 0.03 mgTSS mgCOD −1 ). The kinetic parameters (utilization of organic substrate and denitrification rates) were lower during the start-up period (88.8 mgO 2 L −1 h −1 and 17.37 mgN L −1 h −1 , respectively) than during stable operation of the reactor (212.4 mgO 2 L −1 h −1 and 34.66 mgN L −1 h −1 after 180 cycles). The metagenomic results showed that the abundance of Alcaligenes decreased from 18.39% to 0.88% (in 180 cycle), whereas the read numbers of Trichococcus increased gradually from 2.93% to 52.26% (in 180 cycle). Trichococcus was the dominant microorganism (52.3%). The low value of Y obs most likely resulted from the ability of Trichococcus to degrade complex organic compounds and extracellular polysaccharide substances (EPS), released from dead cells in deeper layers of the biofilm.

The influence of light weight aggregate made of fly ash from sewage sludge thermal treatment (FASSTT LWA) on ammonia nitrogen metabolism, and on quantitative and qualitative changes of microorganisms colonizing the filling, was investigated. Two reactors were used in the experiment. The first was filled with gravel, the other with FASSTT LWA. The reactors were operated with a wastewater hydraulic loading rate of 5 mm(3) mm(-2) d(-1). During the eleven-week experiment, high efficiency of ammonia removal was observed. The lower concentrations of nitrites and nitrates in the effluent indicate that ammonia nitrogen removal resulted not just from nitrification. Nitrate concentration increase was reflected in a decrease in nitrogen removal efficiency. One possible explanation for this phenomenon is that in the period when ammonia nitrogen and nitrites were present in the reactor's FASSTT LWA filling, facilitating conditions occurred for the deammonification process.

The aim of the study was to determine the degree of an organic substrate consumption in the denitrification process involving a biofilm in four-stages laboratory scale rotating biological contactor (RBC). The discs submergence was 40% of their diameter. Acetic acid, used as external carbon source, was fed to the fourth stage of RBC. Consumption of substrate was observed for 2 and 24 hours. For a shorter period there was the removal of 37.9 ± 1.8 mg N·m-2, while using 499,9 ± 33.2 mg O2·m-2 of organic compounds. The prolongation of the experiment duration guaranteed higher efficiency of denitrification. The ratio of organic substrate used to the amount of nitrogen removed was 13: 1 and 21: 1 for 2 and 24 hours respectively.

In this study the effectiveness of sorption Basic Violet 10 were examined (the popular in the industry cationic dye), on 6 different non-conventional sorbents: chitin, sawdust, compost, silage corn, zeolite and fly ash. For each test sorbent was determined optimum pH of sorption. Was also a designated the maximum sorption capacity with respect to the Basic Violet 10. The results obtained were analyzed with the use of three sorption isotherms: Freundlich, Langmuir and double Langmuir. Among the organic sorbents tested, the highest capacity relative to Basic Violet 10 shown sawdust (Qmax = 156.5 mg/g) and corn silage (Qmax = 180.8 mg/g). In the case of mineral sorbents such as zeolite or fly ash, the maximum absorptive capacity Basic Violet 10 was respectively Qmax = 144.1 mg/g and 170.1 mg/g.

The aim of the study was to supplement the information missing in the literature on the influence of organic compounds speciation (percentage of chemical oxygen demand (COD) fractions, readily biodegradable and non–biodegradable dissolved organic matter; slowly biodegradable and non‒biodegradable insoluble organic matter) in wastewater on chemically assisted primary sedimentation process and its potential impact on the energy and economic balance of the plant. The statistical modelling of the chemically assisted primary sedimentation process using artificial neural networks (ANN) was a novelty. It was also important to check the differences resulting from the use of coagulants, polyelectolites and their doses. For both large wastewater treatment plants (>500,000 people equivalent) located in the various regions of the country in Central Europe only ferric chloride had a positive balance. The addition of polyelectrolyte in the Wroclaw wastewater did not affect the chemically assisted primary sedimentation process but in the Bialystok wastewater it strengthened the process effect. In both plants only doses from 10 to 40 mgFe/dm3 are cost-effective. The results indicate that the addition of polyelectrolyte should be taken into account in this application and was correlated with the amount of colloidal COD fractions in wastewater. The developed ANN models reflected well the effectiveness of COD removal in both large WWTP while the sensitivity analysis of individual ANN models showed differences in the variables affecting the calculation process of both models, despite similar values of parameters characterizing wastewater in both wastewater treatment plants.

The hydraulic loading of biofilter (HL), temperature and C/N ratio - these factors influence on nitrogen and carbon removal efficiency from airport wastewater containing de-icing agents. The vast area of airports and significant fluctuations in atmospheric precipitation contribute to huge differences in wastewater flows discharged to treatment systems. The aim of the study was to determine the influence of the hydraulic loading on nitrogen and organic compounds removal in biofilters in low temperatures. The novelty of the paper results from low temperatures (0, 4 and 8 °C), specific wastewater and biofilter filling (light weight aggregates prepared from fly ashes from sewage sludge thermal treatment (FASST LWA). The study was divided into four series differing in the hydraulic loading (1.0, 3.0, 5.0, and 10.0 L·m−2·d−1). In each series, biofilters (filled with FASST LWA) were operated at the temperature of 0, 4, 8 °C and 25 °C. The organic carbon to nitrogen ratio was 0.5. The study showed the effective removal of nitrogen at low temperatures, even at high HL. The highest efficiency of nitrogen removal at the temperature of 0 °C (34.93 ± 4.54%) was obtained at 5.0 L·m−2·d−1. The hydraulic loading and temperature affected the efficiency of nitrogen and COD removal. The presented experiment demonstrated that the use of biofilters filled with FASST LWA may offer an effective and sustainable method for the treatment of airport de-icing wastewater.

Wastewater from households wastewater treatment plants (HWWTP) is discharged to the ground or to the surface waters. Special consideration should be given to the improvement of HWWTP effectiveness, particularly in relation to nutrients. The addition of biodegradable carbon sources to biofilm reactor, can enhance microbial activity but may also lead to filling clogging. The study aimed to compare 3 different organic substrates: acetic acid (commonly applied)and two untypical - citric acid and waste beer, under the same operational conditions in a post-denitrification biofilm reactor. The study investigated the impact of a type of organic substrate, low pH and time on: (1) biofilm growth, (2) the characteristics of extracellular polymeric substances (EPS), (3) the kinetics of nutrients removal and (4) reactor clogging. Results were referred to (5) the effectiveness of nutrients removal. The study demonstrated that low pH assured the development of a thinbiofilm. Citric acid ensured the lowest biomass volume, being by 53% lower than in the reactor with acetic acid and by as much as 61% lower than in the reactor with waste beer. The soluble EPS fraction prevailed in the total EPS in all reactors. The content of the tightly bound EPS fraction ranged from 26.93% (citric acid) to 36.32% (waste beer). Investigations showed also a high ratio of exoproteins to polysaccharide in all fractions, which indicated a significant role of proteins in developing a highly-proliferating biofilm. The treated wastewater met requirements of Polish regulations concerning COD and nitrogen concentrations.

One of the key elements in the operational management of airports is effective de-icing of surfaces. The run-off of precipitation water loaded with pollutants from de-icing is a considerable and costly problem. The aim of our research has been to evaluate the applicability of biofilters filled with light expanded clay aggregate (LECA) generated from incineration of sewage sludge and now serving as a matrix for the development of microorganisms. The tested biofilters treated precipitation water polluted with agents used to de-ice airports. The solution was tested on a laboratory scale, in a range of temperatures from 0 to 25°C, and at concentrations of pollutants from airport de-icing expressed as COD and varying from 503.30 to 3827.50 mg O2·L-1. The tested filling allowed nitrifying as well as denitrifying bacteria to grow and develop even at low temperatures. Biofilters provide simultaneous nitrification and denitrification, as well as removal of organic compounds, even at 0°C. Biofilters based on the granulate prepared from fly ash from sewage sludge thermal treatment can be a cost-efficient and low-maintenance technology to treat airport surface runoff.

The effectiveness of phosphorus removal in vertical-flow filters with double-layer filling composed of light weight aggregate made of fly ashes from sewage sludge thermal treatment (FASSTT LWA) and gravel was determined. Synthetic wastewaters containing 7.36 mg/L of phosphorus were fed into filter columns filled with gravel and FASSTT LWA (gravel was the bed's lower layer, whereas the top layer of the FASSTT LWA constituted 0, 12, 25, 50, and 100% of the depth of the column) at hydraulic loads from 0.003, to 0.007 m/d. The study demonstrated that the efficiency of phosphorus removal depends on the ratio between the gravel and FASSTT LWA. Phosphorus removal is mainly due to adsorption on the surface of the filter filling. The highest phosphorus removal rate was achieved in the filter column with 50% FASSTT LWA and 50% gravel content, irrespective of the hydraulic load applied. The study confirmed the possibility of using FASSTT LWA to produce granular filling and application as the filling of filter columns used for the treatment of wastewaters containing significant concentration of phosphorus.

The operators of wastewater treatment plants in Poland have been observing an increase in the concentration of raw sewage for several years. In particular for organic substances. This is the effect of water consumption reduction, restoration of the sewerage networks, growing wealth, widespread waste of food. The most serious adverse, influencing on the municipal wastewater composition is colloid mills application in gastronomical objects and the discharge of shredded food waste to sewer. That widespread behavior has been noticed and negated, in 2010 year, by the common position of GIS and the ME. Far too late, which confirms the situation observed at the Olsztyn wastewater treatment plant, where the biggest increase of COD values ​​was observed in 2008–2010. The average concentration of COD of sewage in the period 2011–2014 was almost twice higher than in 1996, real PE is close to the design value, despite the fact that the hydraulic load of the object slightly exceeded 50% of design value. Removing such large organic pollutant loads generates high costs, that could be avoided by reasonable food waste management.

A series of investigations were conducted using sequencing batch biofilm reactor (SBBR) to explore the influence of C:N:P ratio on biological dephosphatation including the denitrifying dephosphatation and the denitrification process. Biomass in the reactor occurred mainly in the form of a biofilm attached to completely submerged disks. Acetic acid was used as the source of organic carbon. C:N:P ratios have had a significant effect on the profiles of phosphate release and phosphate uptake and nitrogen removal. The highest rates of phosphate release and phosphate uptake were recorded at the C:N:P ratio of 140:70:7. The C:N ratio of 2.5:1 ensured complete denitrification. The highest rate of denitrification was achieved at the C:N:P ratio of 140:35:7. The increase of nitrogen load caused an increase in phosphates removal until a ratio C:N:P of 140:140:7. Bacteria of the biofilm exposed to alternate conditions of mixing and aeration exhibited enhanced intracellular accumulation of polyphosphates. Also, the structure of the biofilm encouraged anaerobic-aerobic as well as anoxic-anaerobic and absolutely anaerobic conditions in a SBBR. These heterogeneous conditions in the presence of nitrates may be a significant factor determining the promotion of denitrifying polyphosphate accumulating organism (DNPAO) development.

The aim of this study was to evaluate the feasibility of citric acid as external carbon source for biological phosphorus removal. Citric acid was the only source of organic carbon and biomass occurred only as a biofilm. The effect of varying the duration of the mixing and aeration phases on the process of dephosphatation and consumption of organic substrate was examined. The operation consisted of filling (0.5 h), mixing (2.75–8.25 h), aeration (2.75–8.25 h) and draw (0.5 h) phases. Total phosphorus and nitrogen influent concentrations were 7.02 mg P L−1 and 2.05 mg N L−1, respectively. Enhanced intracellular accumulation of polyphosphates (poly-P) and their release in reactors with immobilized biomass (SBBR) was stated. The highest rates of phosphates release (0.059 ± 0.004 g P–PO43− m−2 h−1) and phosphates uptake (0.028 ± 0.002 g P–PO43− m−2 h−1) were observed for mixing to aeration phase duration ratio of 1:3. The percentage of phosphorus in dry matter of biofilm reached 4.6%.

A hydrogel chitosan sorbent ionically cross-linked with sodium citrate and covalently cross-linked with epichlorohydrin was used to remove nutrients from an equimolar mixture of P-PO

This study reports results of respirometric measurements of activated sludge biodegrading the substrate in wastewater originating from the following brewery plant production departments: malt house, brewhouse, fermentation house and racking house. The process was conducted at two temperatures: 10 and 20°C with activated sludge adapted to brewery wastewaters. The loading of activated sludge reached 0.25 g chemical oxygen demand per gram dry matter per day, which assured complete degradation of organic matter. The physicochemical characteristics of the wastewaters are provided. The study demonstrates a correlation between the site of wastewater generation, the specific character of a unitary technological process and the quality of the wastewater discharged to the sewage system, including biodegradability. Despite significant differences in the quality of the wastewaters, they were characterized by high biodegradability at a temperature of 10 and 20°C and by the C:N:P ratio being beneficial for biological treatment, irrespective of their source of origin. Copyright © 2013 The Institute of Brewing & Distilling

This study aims to determine the effect of volatile fatty acids on nitrates and orthophosphate removal in a sequencing batch reactor (SBR) with activated sludge biomass adapted to process dairy wastewater. The research also determine whether it is the type of fatty acid applied that is responsible for the effectiveness of denitrification and dephosphatation at varying nitrate:orthophosphate ratios, or whether these processes are additionally affected by the presence of microorganisms that have adapted to the specific carbon composition of the wastewater being treated. At the beginning of an operating cycle SBRs were dosed with VFAs to provide a source of carbon. A comparative analysis was performed of nitrate and orthophosphate removal at initial nitrate concentrations of 1.22, 7.3 and 15.2 mgN(NO3)L⁻¹. Doses of fatty acids were approximately 10.5 mg⁻¹COD·mgP(PO4). They consisted of acetic, propionic, butyric, isobutyric, valeric, isovaleric and caproic acids. Increases of nitrate concentration from 1.22 to 15.2 mg N(NO3)L⁻¹ were observed to reduce the quantity of removed orthophosphate depending on the fatty acid applied, from 7.2-9.2 mgP(PO4)L to 4.5 - 6.7 mgP(PO4)L. Every increase in the removed nitrates by 5.0 mgN(NO3)L⁻¹ was accompanied by a decrease in the removed orthophosphate of around 1 mgP(PO4)L⁻¹. The reactor containing acetic acid was found to remove the highest amount of orthophosphate irrespective of the nitrates concentration. Acids present in significant amount in dairy wastewaters (i.e. acetic, propionic and butyric) were more effective source of carbon in the denitrification process compared to low concentration acids.