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The Kalina pond has been well known as a severely degraded area in the Silesia region, Poland. The environmental deterioration results from high contamination of water and bottom sediments with recalcitrant and toxic organic compounds, mainly phenol. The study was aimed at developing a bioremediation-based approach suitable for this type of polluted areas, involving microbiological treatment of water as a key and integral part of other necessary actions: mechanical interventions and the use of physical methods. During the initial biological treatment stage, autochthonous microorganisms were isolated from contaminated samples of water, soil and sediment, then subjected to strong selective pressure by incubation with the pollutants, and finally, cultivated to form a specialised microbial consortium consisting of five extremophilic bacterial strains. Consortium propagation and its biodegradation activity were optimised under variant conditions enabling bacteria to proliferate and to obtain high biomass density at large volumes allowing for the in situ application. After installing aeration systems in the pond, the consortium was surface-sprinkled to launch bioremediation and then both bacterial frequency and the contaminant level was systematically monitored. The complex remediation strategy proved efficient and was implemented on an industrial scale enabling successful remedial of the affected site. Treatment with the specifically targeted and adapted microbial consortium allowed for removal of most organic pollutants within a four-month season of 2022: the chemical oxygen demand (COD) value decreased by 72%, polyaromatic hydrocarbon (PAH) level by 97%, while the content of total phenols and other monoaromatic hydrocarbons (BTEX) dropped below the detection thresholds. [ABSTRACT FROM AUTHOR]

The consequence of waste landfilling is the formation of leachate characterized by varying quality and quantity. Although studies on the treatment of leachates have been ongoing for many years, the development of an efficient and effective treatment method remains an open topic. The main goal of this study was to analyze the performance and efficiency of reverse osmosis (RO) in treating young and stabilized landfill leachate. To achieve the purpose of the work, the samples of each kind of leachate were collected from municipal landfills in north-eastern Poland. Then both young and matured leachate were directed into the RO system for treatment. In raw and treated leachate (permeate) samples following parameters were analyzed: pH, electroconductivity (EC), total dissolved solids, chemical oxygen demand, nitrogen ammonia, total phosphorus, sulfate, iron, chloride, total organic carbon, manganese, and calcium. The performance of the RO system was analyzed based on permeate flux, concentration factor of EC in concentrate and recovery rate. The conducted analysis showed that the RO process displayed better performance for stabilized leachate. Permeate flux during matured leachate filtration was 38.8 L/m² h, while during filtration of young leachate – 29.3 L/m² h. The assumed recovery rate was achieved after 4.5 and 7.0 h, respectively for stabilized and young leachate. The efficiency of purification of young and stabilized leachate by RO was similar: the highest removal rate of over 99% was achieved for Fe and Cl– and over 98% for EC, both for young and matured leachate. The lowest efficiency of purification was noted for sulfate: 88.6% and 83.2%, respectively for young and matured leachate. Considering the operation time of the RO system, the final efficiency of the treatment was achieved faster in the case of the filtration of stabilized leachates. [ABSTRACT FROM AUTHOR]

In this work, the semi-synthetic wastewater made of the leachate derived from non-hazardous municipal waste landfill in Kozodrza (south-eastern Poland) and supplemented by ammonium, was treated in hybrid SBRs to assess the removal efficiency of organic compounds, including humic substances and dissolved fractions, depending on the technological conditions. The technological layout variants concerned both the volumetric proportions of aerated and anoxic zones (0.33 and 0.66) as well as the N/C ratio (0.1 and 0.2). It was found that the efficiency of organic compounds removal (expressed as COD, BOD5 and TOC) was influenced by the geometry of oxygen supply; in the SBRs operating with 0.33 ratio, it was significantly higher compared to that with 0.75 ratio. The analysis also revealed that the N/C ratio set at 0.1 resulted in higher treatment efficiency than that obtained for 0.2. The composition of dissolved organic fractions in outflows was also related both with the SBRs geometry and the N/C ratio. It was found that proportions of TOC and humic substances were significantly lower in the SBRs operating with aeration geometry of 0.33, compared to the ones working with 0.66. Moreover, the N/C ratio of 0.1 led to a higher content of dissolved humic substances and COD in outflows. [ABSTRACT FROM AUTHOR]

• Field measurement of EC adjoined by artificial intelligence-based model to conduct leachate induced pollution in landfill. • To monitor the EC, waste temperature, and moisture, two lysimeter tests were conducted. • ANN, ANFIS and Emotional ANN (EANN) models were developed to determine the parameters affecting the EC. • Transfer learning method were used to predict the missing EC in a lysimeter. Predicting leachate pollutants is of prime importance in detecting the amount of pollution in water resources adjacent to sources of leakage. In this study, Electrical Conductivity (EC) as a physicochemical water pollution parameter with the possibility of portable measurement was used as an indicator of leachate quality for the Tychy-Urbanowice operating and closed landfill complex. In order to simulate landfill conditions, two lysimeter experiments were conducted simultaneously. Using sensors mounted in the lysimeters, from the end of November 2018 to the end of December 2019, EC, waste temperature and waste moisture were measured for the open lysimeter and only waste moisture for the closed lysimeter. Additionally, meteorological data obtained from the nearest synoptic station and soil moisture and temperature acquired from the GLDAS satellite were employed as external data to analyze various conditions. Thereafter, Artificial Neural Network (ANN), Neuro-Fuzzy Inference System (ANFIS), and Emotional ANN (EANN) models were developed to determine the parameters affecting the EC value recorded for the open lysimeter and subsequently, predict the missing EC parameter of the closed lysimeter by employing the transfer learning method. Following that, in order to improve the precision of EC predictions, ensemble techniques were applied to the outputs of the models that were developed. The results showed that the moisture of the lysimeters made a significant contribution to the EC value prediction. It is worth mentioning that among ANN, ANFIS, and EANN, the EANN model yielded more precise results in EC estimation, with the average DC above 0.80 and 0.90 for individual and ensembled modeling in both the training and verification phases, respectively. [ABSTRACT FROM AUTHOR]

The performance of three constructed wetland systems treating landfill leachate, two located in northern Poland (Szadółki near Gdańsk and Gatka near Miastko) and one in southern Sweden (Örebro), is discussed. The CWs differ in size, hydraulic regime, type of hydrophytic plants, and type of leachate pre-treatment before discharging to the CW. The CW in Szadółki consists of two parallel beds with sub-surface, horizontal flow of leachate (HSSF) planted with reed. The leachate is discharged to the CW without pre-treatment. The facility in Gatka is a willow plantation that receives leachate after preliminary sedimentation in a retention pond. The system at Örebro consists of a series of ponds with a surface flow of leachate (the free water surface - FWS wetland), preceded by pre-treatment in an aerated tank with nitrogen stripping. A comparison of treatment conditions and results is presented. The best treatment efficiencies were observed at the CW Örebro (98% TSS, 91% BOD, 65% COD, 99.5% N-NH4 +), which resulted from: (i) an effective pre-treatment of leachate before it was discharged to the CW, and (ii) the CW type - with surface flow of leachate (FWS). At the sub-surface flow wetlands (Szadółki, Gatka), clogging problems occurred due to lack of or unsatisfactory pre-treatment of leachate, resulting in lower treatment efficiencies. The ammonia nitrogen was still removed at the clogged facilities with the efficiencies varying from 52 to 89%, while the organics removal efficiencies were substantially lower (27-61% for BOD5 and 2-35% for COD). [ABSTRACT FROM AUTHOR]

Leachate generated in landfills are characterized by high toxicity related to, high concentrations of organic and non-organic pollutants, therefore, it is advisable to use highly effective methods of their purification to prevent environmental contamination. The aim of this study was to determine the treatment efficiency of landfill leachate during the application of integrated processes: advanced oxidation (AOP) and biochar adsorption (BC). In the case of the AOP, the chemical process was the Fenton reaction in which the source of hydroxyl radicals was H 2 O 2 (system I) and SPC - sodium percarbonate (system II). Leachate was derived from the regional municipal waste landfill in Silesian Province (Poland) which was characterized by the pH of 8.40, COD value was 3155 mg L -1 and BOD was under 165 mg L -1 . The BOD/COD ratio was at a low level (0.053) that indicated low biodegradability. The applied systems allowed of the COD reduction index to the level of 549 mg L -1 (H 2 O 2 +BC) and 944 mg L -1 (SPC+BC) where the limit threshold is 125 mg L -1 . In the same case of the TOC index, these values were respectively 119 and 186 mg L -1 , where the limit value is 30 mg L -1 .This study has been aimed to estimate the toxicity of leachate treatment in integrated systems: AOP processes + biochar adsorption. Toxicity of treated and untreated leachate has been analysed by Sinapis alba and Lepidium sativum plants-based tests. It was found that while conducting the Fenton process as system I (H 2 O 2 ) at all reagent doses, the removal efficiency of COD and TOC was 17% and 12% higher, respectively, compared to system II. The most advantageous dose of regents was 2.5:1 and biochar - 2 g L -1 . It was observed that in the SPC+BC system the roots of L. sativum and S. alba were on average 34% and 28% longer compared to the H 2 O 2 +BC system. Higher germination index (GI) of both tested plants, indicating lower wastewater toxicity, was recorded for the SPC+BC system., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

The present study was aimed to determine the impact of municipal waste landfill on the pollution level of surface waters, and to investigate whether the choice and number of physical and chemical parameters monitored are sufficient for determining the actual risk related to bioavailability and mobility of contaminants. In 2007-2012, water samples were collected from the stream flowing through the site at two sampling locations, i.e. before the stream׳s entry to the landfill, and at the stream outlet from the landfill. The impact of leachate on the quality of stream water was observed in all samples. In 2007-2010, high values of TOC and conductivity in samples collected down the stream from the landfill were observed; the toxicity of these samples was much greater than that of samples collected up the stream from the landfill. In 2010-2012, a significant decrease of conductivity and TOC was observed, which may be related to the modernization of the landfill. Three tests were used to evaluate the toxicity of sampled water. As a novelty the application of Phytotoxkit F™ for determining water toxicity should be considered. Microtox(®) showed the lowest sensitivity of evaluating the toxicity of water samples, while Phytotoxkit F™ showed the highest. High mortality rates of Thamnocephalus platyurus in Thamnotoxkit F™ test can be caused by high conductivity, high concentration of TOC or the presence of compounds which are not accounted for in the water quality monitoring program., (Copyright © 2014 Elsevier Inc. All rights reserved.)

In this study, performance of a lab-scale two-step treatment system was evaluated for removal of toxic metal ions from landfill leachate. The technology of polymer inclusion membranes (PIMs) was the first step, while the second step of the treatment system was based on sorption on impregnated resin. The PIMs were synthesized from cellulose triacetate as a support, macrocyclic compound i.e. alkyl derivative of resorcinarene as a ionic carrier and o-nitrophenyl pentyl ether as a plasticizer. The transport experiments through PIM were carried out in a permeation cell, in which the membrane film was tightly clamped between two cell compartments. The sorption tests were carried out using a column filled with a resin impregnated with resorcinarene derivative. The obtained results show the good performance with respect to the removal of heavy metals from landfill leachate with the overall removal efficiency of 99%, 88% and 55% for Pb(II), Cd(II) and Zn(II) ions, respectively. Moreover the contents of metal ions in the leachate sample after treatment system were below permissible limit for wastewater according to the Polish Standards., (Copyright © 2012 Elsevier Ltd. All rights reserved.)