Low Concentrations Of Heavy Metals Research Articles

公路源重金属对青藏高原高寒草甸土壤线虫群落的影响

为了解重金属对青藏高原高寒草甸土壤线虫群落的影响，在邦杰塘草原利用公路源重金属含量差异，采用高通量测序技术，分析重金属对高寒草甸土壤线虫群落多样性及群落组成的影响。结果表明：在重金属含量较低样本中，土壤线虫群落Shannon指数、Ace指数、Chao指数比重金属含量较高样本均要小，且整体上Shannon指数、Ace指数、Chao指数与重金属含量较高样本差异显著（P<0.05）。重金属含量升高改变了高寒草甸土壤线虫纲水平和目水平的群落结构，使近自然状况下的色矛纲（Chromadorea）、小杆目（Rhabdtida）优势土壤线虫群落转变为一类未分类线虫纲（unclassified_p_Nematoda）、一类未分类线虫目（unclassified_p_Nematoda）的优势土壤线虫群落。重金属Cu、Pb、Zn、Cd与线虫门（Nematoda）和刺嘴纲（Enoplea）正相关，但与色矛纲（Chromadorea）负相关，且对土壤线虫Chao指数的变异解释比例依次减小。研究表明土壤重金属含量对青藏高原高寒草甸土壤线虫群落多样性及组成产生很大影响，但仍需对高寒草甸区域进行系统的土壤线虫调查，并丰富土壤线虫生物信息数据库。;Soil nematode is a sensitive soil organism. In order to understand the effects of heavy metals on the alpine meadow soil nematode community in the Tibet Plateau, this study based on the differences in heavy metals content from highway sources in the Bangjietang grassland used the high-throughput sequencing technology to analyze the influence of heavy metals on the diversity and community structure of the alpine meadow soil nematode community. In August 2019, we collected soil samples at 0, 5, 15, 30, 50 and 75 m away from the highway in Bangjietang grassland. Cu, Pb, Zn, Cd were determined by flame atomic absorption spectrophotometry, and the community composition and structure of soil nematode were determined by high-throughput sequencing technology. The influence of heavy metals on soil nematode community was discussed by redundancy analysis. The results showed that the Shannon index, Ace index and Chao index of the soil nematode community in the samples with lower heavy metal content were smaller than the samples with higher heavy metal content (P<0.05). The increase of heavy metal content changed the community structure of soil nematode in alpine meadow, and the dominant soil nematode communities of Chromadorea and Rhabdtida under the natural conditions were transformed into the dominant soil nematoda communities of unclassified_p_Nematoda and unclassified_p_Nematoda. Cu, Pb, Zn and Cd were positively correlated with Nematoda and Enoplea, but negatively correlated with Chromadorea. The proportion of Cu, Pb, Zn, Cd to the variation explanation of Chao index decreased successively. The study shows that soil heavy metal content has a great influence on the diversity and structure of soil nematode community in alpine meadow of the Tibet Plateau, but it is still necessary to conduct a systematic investigation of soil nematode in alpine meadow and enrich the database of biological information of soil nematode.

Isotopic and hydrogeochemical characterization of groundwater and surface water from a mine site in Tanzania

Abstract This study used the hydrochemical properties of water to reveal the causes of water quality degradation. The results showed that most samples located downstream of the mine tailings dam were slightly acidic with pH as low as 4.6. Samples with high levels of Na+, Cl−, and could not be isotopically linked to the local geochemistry, but the anthropogenic activities and evaporation were probably responsible for the observed water chemistry. The Piper diagram indicated cations were dominated by Ca and Mg, while anions were dominated by bicarbonates and sulphates. Pb and Hg levels (mean 70.29 and 17.95 μg/L, respectively) were all higher than the World Health Organization (WHO) and Tanzanian drinking water guidelines. Mining activities probably contributed to the observed low pH values and elevated concentration of cyanides, heavy metals, and metalloids. Stable isotope results indicated a vulnerability of the water to recent contamination that could be attributed to anthropogenic activities. Moreover, isotopic studies indicated a flow pattern from the eastern to the western side of the mine study site. Lowland samples were more 3H-enriched than highland ones. The present study concludes that groundwater recharge from recent local precipitation may have an impact on the sources studied.

Features of the heavy metals content accumulation in grain of spring barley varieties (Hordeum sativum) for different applications as affected by the duration of storage

Purpose. Investigate the content of heavy metals in spring barley varieties for different applications depending on the duration of grain storage.&#x0D; Methods. Laboratory, analytical, statistical.&#x0D; Results. It was found that the studied varieties, regardless of the application had an individual accumulation of heavy metals. Grain varieties have an inverse relationship with the intensity of lead concentration in the grain of spring barley: the longer the storage, the lower its content in the grain. The accumulation of heavy metals of mercury (Hg) and arsenic (As) in the grain of spring barley varieties of grain use allows us to note that with increasing storage, their content decreases. It was found that the accumulation of heavy metals copper (Cu) and zinc (Zn) in the grain of spring barley for grain increases as affected by the storage period. There was a decrease in zinc content after a month of storage and depending on varietal characteristics. A slight increase, in the varieties of the brewery application was found after three and six months of grain storage. When analyzing the data, it can be noted that after nine months and a year of storage, there was an increase in the copper content, but to the maximum permitted level.&#x0D; Conclusions. Varieties of spring barley, regardless of the application, had an individual accumulation of heavy metals. Varieties ‘Stalker’ and ‘Ahrarii’ are sensitive to lead: the content of this element immediately after threshing was 1.08 mg/kg and 1.12 mg/kg. A month later, these figures were 0.73 mg/kg and 1.02 mg/kg. Storage of spring barley grain for 9 and 12 months shows that the accumulation of cadmium has increased compared to the indicators obtained immediately after threshing. Thus, in the varieties ‘Stalker’ this figure was 0.09 mg/kg, and in ‘Ahrarii’ 0.13 and 0.014 mg/kg. The most sensitive to the accumulation of copper (Cu) immediately after threshing were varieties ‘Ahrarii’ with 3.00 mg/kg and ‘Vzirets’ with 2.56 mg/kg, and the lowest content had varieties ‘Shchedryk’ with 2.27 mg/kg and ‘Stalker’ with 2.31 mg/kg. ‘Enei’ variety of universal application was characterizing by a lower content of heavy metals in comparison with grain varieties. In spring malting barley, depending on the duration of grain storage, it was found that as in previous grain and universal application, the content of heavy metals accumulates differently depending on the varietal characteristics.

Diversity and Genomic Characterization of a Novel Parvarchaeota Family in Acid Mine Drainage Sediments.

Recent genome-resolved metagenomic analyses of microbial communities from diverse environments have led to the discovery of many novel lineages that significantly expand the phylogenetic breadth of Archaea. Here, we report the genomic characterization of a new archaeal family based on five metagenome-assembled genomes retrieved from acid mine drainage sediments. Phylogenomic analyses placed these uncultivated archaea at the root of the candidate phylum Parvarchaeota, which expand this lesser-known phylum into two family levels. Genes involved in environmental adaptation and carbohydrate and protein utilization were identified in the ultra-small genomes (estimated size 0.53–0.76 Mb), indicating a survival strategy in this harsh environment (low pH and high heavy metal content). The detection of genes with homology to sulfocyanin suggested a potential involvement in iron cycling. Nevertheless, the absence of the ability to synthesize amino acids and nucleotides implies that these archaea may acquire these biomolecules from the environment or other community members. Applying evolutionary history analysis to Parvarchaeota suggested that members of the two families could broaden their niches by acquiring the potentials of utilizing different substrates. This study expands our knowledge of the diversity, metabolic capacity, and evolutionary history of the Parvarchaeota.

Assessing biochemical responses of filamentous algae integrated with surface waters in Yavuzeli-Araban catchment

The present study aimed to investigate biochemical responses of filamentous algae integrated with surface waters in Yavuzeli-Araban catchment (the south-east of Turkey) by the use of a multivariate approach. This catchment having anthropogenic activities and different climate could affect environmental variables of surface waters, changed the biochemical compounds of filamentous species. A canonical correspondence analysis elucidated that heavy metals, water temperature, and nutrients were found to be major environmental factors governing the occurrence/succession and biochemical contents of filamentous algae. Cladophora glomerata is mainly linked with water temperature, antimony, orthophosphate, and conductivity, whereas Spirogyra majuscula related to nitrate and lead. Filamentous algae obtained from various sampling stations had different biochemical responses to different physicochemical factors. The biochemical responses of species were significantly different between sampling stations (p < 0.05) at different sampling seasons. Relatively high nutrients and low heavy metal contents stimulated the formation of pigments and total protein content by filamentous algae. On the other hand, increment in heavy metal ions in ecosystems lead to increase malondialdehyde, hydrogen peroxide, proline, total thiol group, and total phenolic compounds by filamentous algae. A significant positive relation between heavy metal ions and mentioned biochemical compounds observed from the Pearson correlation test. Besides, the surface structure of algal biomass changed concerning the different responses of species under various environmental conditions, indicated by the Fourier transform infrared analysis. Filamentous algal species showed different temporal and spatial occurrences in the region, which could be due to the biochemical responses of algae species to different complex environmental conditions. A significant increment in mentioned biochemical compound levels in filamentous algae obtained from a different broad of habitats and their sensitivity/tolerance to the environmental condition could make them valuable bioindicators.

Robust cellulose-based composite adsorption membrane for heavy metal removal

Adsorptive membranes offer an effective mode to remove heavy metal ions from contaminated water, due to the synergies made possible by low-cost, high-affinity adsorbents and highly scalable filtration in one system. However, the development of adsorptive membranes is hampered by their instability in the aqueous phase and low binding affinity with a broad spectrum of heavy metals in a reasonable flux. Herein, a regenerated cellulose support membrane is strongly grafted with stable and covalent-bonded polyelectrolyte active layers synthesized by a reactive layer-by-layer (LBL) assembly method. The LBL assembled layers have been successfully tested by scanning electron microscopy, Fourier-transform infrared spectroscopy and X-ray photo-electron spectroscopy. The covalent bonding provides the membrane with long-term stability and a tunable water flux compared to a membrane assembled by electrostatic bonding. The maximum adsorption capacity of the membrane active layers can reach up to 194 mg/g, showing more efficient adsorption at lower heavy metal concentration and higher pH value of feed solution. The membrane can remove multiple ions, such as Cu, Pb, and Cd, by adsorption and is easy to be regenerated and recovered. The strong covalent bonding can extend the membrane lifetime in water purification to remove multiple heavy metals at high efficiency.

Cell Viability and Immune Response to Low Concentrations of Nickel and Cadmium: An In Vitro Model.

Environmental exposure to low concentrations of heavy metals is common in the general population, but the toxicity, immune response mechanisms, and the effects of single and mixed metal exposures have not been clearly identified. In this study, A549 cells and Raw264.7 cells were exposed to low concentrations of the heavy metals nickel (Ni) and cadmium (Cd) for 24, 48, and 72 h, and then cell viability and cytokine levels were analyzed. We found that exposure to low concentrations of Ni (50 nM) or Cd (10 nM) alone did not affect cell viability. However, mixing them together decreased cell viability. In addition, the levels of IL-10, IL-12, and TNF-α decreased with single (only Cd) and mixed (Ni and Cd) exposures. These results show that exposure to low concentrations of heavy metals could affect the normal immune response, even without obvious clinical manifestations. Therefore, chronic exposure to heavy metals might have adverse effects on overall health.

Trophic status of water and level of pollutants as measures of efficiency of water treatment regime at Kafr El-Shinawy drinking-water treatment plant, Damietta

This work aims to study the seasonal fluctuation in physicochemical characteristics, trophic status, and some chemical and biological pollutants influencing phytoplankton diversity, and water quality in raw and treated water at Kafr El-Shinawy drinking-water treatment plant, Damietta - Egypt seasonally during 2018. Phytoplankton distribution was affected by the trophic status of water, level of pollutants, and physicochemical treatment processes (coagulation, flocculation and sedimentation) of water. The predominance of phytoplankton species, especially Aphanizomenon flos aquae (Cyanophyta), Gomphosphaeria lacustris (Cyanophyta), Microcystis aeruginosa (Cyanophyta), Nostoc punctiforme (Cyanophyta), Oscillatoria limnetica (Cyanophyta), Pediastrum simplex (Chlorophyta), and Melosira granulata (Bacillariophyta) in treated water was much less than in raw water. Trihalomethanes (THMs) levels in treated waters were higher than in raw water. On the contrary, lower concentrations of heavy metals were recorded in treated water. Phytoplankton cells exhibited a bioaccumulation capacity for heavy metals especially Mn, Zn, and Fe in both raw and treated water. Intracellular levels of microcystins were lower (0.003 - 0.011µg L−1) whereas the extracellular levels were higher (1.00 – 2.01 µg L−1) in treated water than raw water, and the former recorded the highest level in raw water during summer (1.3 µg L−1). Hence, the levels of dissolved microcystins and THMs in treated water were higher than the allowable limit, especially during summer, the season of luxurious growth of Microcystis species.

Production of genome-edited Daphnia for heavy metal detection by fluorescence

Aquatic heavy metal pollution is a growing concern. To facilitate heavy metal monitoring in water, we developed transgenic Daphnia that are highly sensitive to heavy metals and respond to them rapidly. Metallothionein A, which was a metal response gene, and its promoter region was obtained from Daphnia magna. A chimeric gene fusing the promoter region with a green fluorescent protein (GFP) gene was integrated into D. magna using the TALEN technique and transgenic Daphnia named D. magna MetalloG were produced. When D. magna MetalloG was exposed to heavy metal solutions for 1 h, GFP expression was induced only in their midgut and hepatopancreas. The lowest concentrations of heavy metals that activated GFP expression were 1.2 µM Zn2+, 130 nM Cu2+, and 70 nM Cd2+. Heavy metal exposure for 24 h could lower the thresholds even further. D. magna MetalloG facilitates aqueous heavy metal detection and might enhance water quality monitoring.

Potential of Producing Compost from Source-Separated Municipal Organic Waste (A Case Study in Shiraz, Iran)

Developing countries face serious environmental, social and economic challenges in managing different types of organic waste. Proper treatment strategies should be adopted by solid waste management systems in order to address these concerns. Among all of the treatment options for organic waste, composting is the most approved method as an effective strategy to divert solid waste from landfills. This experimental research aimed to examine the potential of producing compost from source-separated municipal organic waste in Shiraz, Iran. Market waste (fruits and vegetables) and garden waste (plant residues) were used as the raw input materials. They were subjected to the windrow pile composting method in an open site area. The process was monitored against several physical, chemical and biological parameters. In-situ measurements (temperature and moisture content) were carried out on a daily basis. Sampling and lab analyses were conducted over the period of the biological treatment. The final product was of acceptable moisture and nutrient levels, pH, Electrical Conductivity (EC), and Carbon/Nitrogen ratio. All of the analyzed compost samples had lower concentrations of heavy metals than the Iranian and German standards. Overall, the results obtained revealed that composting is a promising method for municipal organic waste treatment. The findings also imply the effectiveness of the source-separation collection method in the production of high-quality compost.

Biodegradable, Hygienic, and Compostable Tableware from Hybrid Sugarcane and Bamboo Fibers as Plastic Alternative

<h2>Summary</h2> In this study, we developed a pathway to valorize sugarcane bagasse left from sugar production to food-related end products through pulp molding, which represents a sustainable material and clean manufacturing. The sugarcane bagasse from the sugar industry is naturally safe for food-related applications. The produced tableware is fully biodegradable, renewable, and environmentally friendly. We also developed a hybrid fiber strategy that long bamboo fibers were blended with short sugarcane fibers, which formed abundant physical interwinding in the obtained tableware with superior performances as required for food containers, including high tensile strength, superior oil stability, excellent hydrophobicity, and low heavy metal content. Of note, our tableware was mostly biodegraded under natural conditions within 60 days, which is largely shorter than the degradation time for synthetic plastics. Moreover, in comparison with polystyrene production, pulp molding produced much less CO₂ emission. The tableware made from biomass thus represents an eco-friendly, low cost, and biodegradable alternative to synthetic plastics for food packaging.

INFLUENCE OF BIOLOGIZED FERTILIZER SYSTEMS ON THE INTENSITY OF ACCUMULATION OF HEAVY METALS IN LEGUME-FORBS PLANTS

The influence of improvement of natural forage lands on the intensity of accumulation of PB, Cd, Zn and Cu in cereal and legume grasses for application of organic fertilizers and defects to the soil has been studied. It has been proved that the high efficiency of reduction of lead and cadmium in legume-forbs plants for improving the condition of natural forage lands in the area of their local pollution was followed by the introduction of organic matter and defects into the soil. It was also found that with the increase of vegetation years of forbs and legumes of natural fodder lands for the introduction of organic fertilizers and defects, the concentration of lead, cadmium, zinc and copper in it decreased. As a result of theoretical analysis and experimental research, the level of heavy metal contamination of plant biodiversity of natural forage lands at different man-made loads was studied. The intensity of pollution of plant biodiversity of absolute land, normal land and land of excessive moisture of dry lowland meadows of Vinnytsia Pb, Cd, Zn and Cu in the conditions of different technogenic loading is estimated. It was found that with a radical improvement of natural forage lands of dry lowland meadows compared to the surface in the conditions of local pollution, a lower intensity of grass accumulation of heavy metals was observed already in the 1st year of vegetation. The analysis of the obtained results allows us to conclude that the vegetation of natural forage lands in the conditions of local pollution of Vinnytsia region can accumulate above the allowable level of cadmium, which is characteristic of dry moisture, relatively lower content of heavy metals. Under the agrochemical impact on natural forage lands there is a certain pollution of their heavy metals, the accumulation of which in the vegetation depended on the system of tillage with the use of organic matter, relatively higher than mineral fertilization with surface tillage. Key words: lead, cadmium, zinc, copper, grass and legumes, natural forage lands.

Effect of Cadmium and Nickel Exposure on Early Development in Zebrafish (Danio rerio) Embryos

Exposure to even low concentrations of heavy metals can be toxic to aquatic organisms, especially during embryonic development. Thus, this study aimed to investigate the toxicity of nickel and cadmium in zebrafish (Danio rerio) embryos exposed to environmentally relevant concentrations of each metal alone or in combination from 4 h through to 72 h postfertilization. Neither metal altered survival, but individual and combined exposures decreased hatching rate. Whereas cadmium did not affect total body length, trunk area, eye diameter, or eye area, nickel alone and in combination with cadmium decreased each morphological parameter. Yolk sac area, an index of metabolic rate, was not affected by nickel, but was larger in embryos exposed to high cadmium concentrations or nickel and cadmium combined at high concentrations. Nickel decreased spontaneous movement, whereas cadmium alone or nickel and cadmium combined had no effect. Neither metal altered elicited movement, but nickel and cadmium combined decreased elicited movement. Myosin protein expression in skeletal muscle was not altered by cadmium exposure. However, exposure to nickel at low concentrations and combined exposure to nickel and cadmium decreased myosin expression. Overall, nickel was more toxic than cadmium. In conclusion, we observed that combined exposures had a greater effect on movement than gross morphology, and no significant additive or synergistic interactions were present. These results imply that nickel and cadmium are toxic to developing embryos, even at very low exposure concentrations, and that these metals act via different mechanisms.

Effects of Fruit and Vegetable Wastes and Biodegradable Municipal Wastes Co-Mixed Composts on Nitrogen Dynamics in an Oxisol

Organic waste generation in developing countries is increasing and appropriate disposal methods are needed. An open aerobic composting using 20 L bins was carried out using 6 composts made using ratios of 3:1, 1:2 and 1:4 fruit and vegetable wastes (FVW):biodegradable municipal waste (BMW), with and without addition of homemade indigenous microorganisms (IMO), for 30 days to monitor compost quality. The nitrogen contents of the composts ranged from 1.52 to 2.76% N equivalent to 76–138 kg N ha−1 at 5 t ha−1 compost application rates. Heavy metals measured were below permissible levels of compost quality standards. Selected composts were incubated for 60 days to study nitrogen mineralization dynamics when applied to an Oxisol at the rates of 0, 5 and 10 t ha−1. The results showed significant differences (p ≤ 0.05) in the amounts of NH4-N, NO3-N and cumulative NH4-N + NO3-N released. Ammonium nitrogen released was higher on days 3, 21 and/or 40 for composts 3:1 − IMO at 10 t ha−1, 3:1 + IMO at 10 t ha−1 and 3:1 − IMO at 5 t ha−1. Cumulative N (NH4 -N + NO3 -N) released over control were 77.98, 64.09 and 64.35% higher for application of 3:1 + IMO, 1:2 − IMO and 1:2 + IMO, respectively, at an application rate of 10 t ha−1. The increased nitrogen content, low heavy metals concentrations and the amount of mineralized N from the composts exhibit potential for increased nutrient availability when applied to a soil.

PHOSPHORUS RECOVERY FROM WASTE AS STRUVITE

The paper gives information on the depletion of phosphorus (P) as an important element for all forms of life and its pollution impact on the environment in case of intensive discharge of phosphorus compounds into water bodies. Two secondary waste sources of Phosphorus are under consideration, namely the domestic wastewater and sludge and animal manure. The characteristics of these two fluids regarding organic matter and nutrient content are summarized. Discussing the techniques for P extraction mostly attention is given to phosphorus precipitation as ammonium magnesium phosphate (struvite). Examples of effectiveness of P precipitation as struvite in Municipal Wastewater Treatment Plants (MWWTPs) with chemical and biological P removal are presented. The examples of struvite production from sewage and manure waste show evidently the great potential of utilization of such a waste as a source of phosphorus. The recovered product is valuable both as it is a slow release fertilizer and with its low content of heavy metals compared to the mineral fertilizers. In respect of the diminishing amount of natural P rocks, the sewagec wastewater and sludge and the animal manure can be regarded as an important secondary source of Phosphorus.

Concentration of heavy metals in street dust: an implication of using different geochemical background data in estimating the level of heavy metal pollution

Geochemical background data are used to distinguish between the sources of heavy metal (natural or anthropogenic) and to categorize the level of heavy metal pollution. In this study, we present the results of using different geochemical backgrounds (BG1–BG3) to establish the level of heavy metal pollution in street dust in Warsaw, Poland. We applied individual and collective indicators calculated with respect to the following backgrounds: (1) upper continental crust (UCC) (BG1), (2) the regional geochemical background established for Quaternary surface deposits of the Mazovian region (Poland) (parent geological material occurring in the studied area, Warsaw, Poland) (BG2), and (3) the minimal values of the concentration of heavy metals determined for the real street dust sample collectives from Warsaw (BG3). The assessment of the heavy metals pollution of street dust significantly depended on the background values used in the calculation of individual and collective indicators. Street dust was classified as unpolluted for almost all the heavy metals based on the values of indicators calculated for UCC data. The effect of traffic-related pollution was detected more precisely based on the values of indicators calculated for BG2 and BG3. The naturally elevated concentrations of heavy metals in UCC data can be responsible for the underestimation of pollution impact in street dust. When relatively low concentration of heavy metals is only observed, the application of BG2 or BG3 background data, which better correspond to the geogenic material in street dust, allows to realistically reflect the level of pollution from moving vehicles.Graphic abstract

The role of Serendipita indica and Lactobacilli mixtures on mitigating mycotoxins and heavy metals\u2019 risks of contaminated sewage sludge and its composts

Accumulation of the Municipal Sewage Sludge (MSS) is considered as one of the most harmful renewable ecological and human health problems. MSS is a renewable resource that could be used as a soil organic amendment. This study aims to reduce the Heavy Metals (HMs) from the sludge content and sludge compost. Furthermore, this study is considered the first to assess the mycotoxins content in sludge and sludge compost via a new biological treatment using the fungus Serendipita indica or a mixture of lactic acid bacteria, thus providing safer nutrients for the soil amendment for a longer time and preserving human health. The HMs and mycotoxins were determined. The results exhibited that the biotic remediation of bio-solid waste and sewage sludge compost succeeded; a new bio-treated compost with a very low content of heavy metals and almost mycotoxins-free contents was availed. Also, the results indicated that the Lactobacilli mixture realized the best results in reducing heavy metals contents and mycotoxins. Afterward, S. indica. biotic remediation of bio-solid waste and sewage sludge compost minimized the health risk hazards affecting the human food chain, allowing for the different uses of sludge to be safer for the environment.

Comparison of dried sludge and sludge ash for phosphorus recovery with acidic and alkaline leaching

AbstractNowadays, the recovery of phosphorus has been in the spotlight due to its importance for food security and depleting sources. In this study, phosphorus recovery from dried sewage sludge and sludge ash by acid and alkaline leaching was evaluated. Optimum extraction time and temperature were determined as two hours and ambient temperature. Results showed the superiority of strong acidic conditions for leaching; 75 ml/g with 0.4N HCl and 25 ml/g with 0.6N HCl were determined as optimum conditions to achieve efficient phosphorus dissolution from sludge ash (94.6%) and dried sludge (91.1%), respectively, with the lower heavy metal concentrations. Lower L/S ratio put forward the dried sludge as a more advantageous resource for phosphorus extraction. Besides, by alkaline leaching of sludge ash and dried sludge, 60.3 and 70.3% phosphorus dissolutions were achieved with 75 ml/g and 1N NaOH; and the leachate was a suitable product for phosphorus precipitation due to its high pH.

Analysis of rejects from waste printed circuit board processing as an alternative fuel for the cement industry.

Waste Printed circuit boards (PCBs) are one of the most valuable and recycled components of electronic waste due to the presence of precious metals such as copper, silver, gold and palladium. The rejects of the PCB recycling process, named non-metal fraction (NMF) have continuously been sent to landfills. Several researchers have proposed alternative use of NMF as secondary materials such as fillers in composites or as adsorbent. This study is focused on the potential application of the PCB recycling rejects as waste-derived fuel or alternative fuel in the cement industry. Approximately 2 million metric tonnes (Mt) of this waste was produced in 2014 globally and estimated to reach 6.5 million Mt in 2050. The presence of high organic matter in the NMF renders it useful as an alternative fuel. The organic content of the NMF could also potentially be increased using gravity separation and thus increasing its net calorific value. The study showed that the NMF could provide up to 21 MJ kg-1 of heating value with low heavy metal and ash concentration. A comparison with other waste-derived fuel sources is also presented in the paper.

Development of wafers with fillings made from organic raw materials with improved consumer properties

To improve the fatty acid and amino acid composition, as well as the organoleptic characteristics of flour confectionery products, new formulations for wafers Summer Temptation and Coconut Delight with fillings made from organic raw materials have been developed. Both products' formulations contain pure organic raw materials. The composition of Summer Temptation wafers includes buckwheat flour, cane sugar, butter, skimmed milk powder, sea buckthorn oil, and lemongrass powder. Rice flour, coconut sugar, dry coconut milk, coconut oil, lemongrass powder are added to the composition of Coconut Delight wafers. The developed products have excellent organoleptic characteristics that are confirmed by the conclusions from a tasting board. Safety indicators also comply with regulatory requirements. Both samples are distinguished by a lower content of heavy metals compared to control. Since the fatty base and flour were replaced in the new samples in comparison with the control formulation, the fatty acid and amino acid compositions of the products were investigated. The sample, based on organic buckwheat flour, demonstrated the best amino acid composition. The content of essential amino acids in the sample Coconut Delight increased slightly. The content of saturated fatty acids decreased by almost 1.5 times in both developed products. At the same time, the content of unsaturated fatty acids in both types of wafers increased by almost 4 times in comparison with control. These results indicate that the use of organic raw materials in the production of wafers with fillings improves their consumer properties. The addition of unconventional organic oils to the fillings improves the fatty acid composition while the replacement of flour in wafer sheets improves the amino acid composition. The obtained results can be used at enterprises in the food industry to expand the range of organic products