Precipitation of copper (II) in a two-stage continuous treatment system using sulfate reducing bacteria

Biologically driven precipitation of dissolved copper and other trace metals has been used to treat contaminated aqueous streams. However, high dissolved trace metal concentrations can lead to toxicity, and their bioremediation difficult. Furthermore sorption of trace metals onto biomass might result in large amounts of contaminated byproducts. The aim of this work was to develop and test a two-stage reactor to bypass the toxic effects on the bacteria and chemically precipitate copper without contaminating the bulk of the biomass. Hence, copper removal using a sulfate reducing bacteria culture was investigated in a two-stage continuous treatment system. The first reactor was a sand-filled biological reactor in which the sulfate is reduced, followed by a second reactor/clarifier where the chemical precipitation and sedimentation of a CuS phase occurs. The influent Cu2+ concentration was varied systematically between 15 and 600 mg/L, and the precipitation of Cu2+ metal as CuS was achieved in the second reactor, resulting in complete (within detection limits) Cu2+ removal. EDS analysis on the solid phase collected from the second reactor confirmed the presence of Cu and S in the precipitate. EDS analysis on the solid phase collected from the second reactor confirmed the presence of Cu and S in the precipitate, and a CuS phase with minimal biomass was obtained. This configuration avoids toxicity effects of heavy metals in the biological reactor, as well as the contamination of biomass with the trace metal. Furthermore, the biomass free CuS precipitates can be easily disposed or even used to recover the trace metal

Murgul bakır madeni ve çevresindeki toprak ve sedimentlerde meydana gelen ağır metal kirliliğinin değerlendirilmesi

Abstract Aim of study: This study focuses on the changes of heavy metal pollution in soil and sediment. Study area: The study area covers Murgul district of Artvin located over the Eastern Black Sea region, Turkey. Material and method: Sampling areas were determined at distances in the direction of surface flow along the stream route where waste water was discharged by assuming the Copper Plant as the central point. A total of 54 soil and 10 sediment samples were taken from sampling points. Main results: The results of analysis of soil and sediment samples indicated that the mean values of Copper, Lead and Zinc were remarkably higher than the threshold values and the soil pH decreased as it moved away from the center point. The contaminated sediments, deposited over the years in the river bank sediments may act as secondary source of pollution to the covering water column in the river. Research highlights: Heavy metals from the soil during the rehabilitation activities to be applied in the mining sites, it is suggested to investigate the phytoremediation techniques, which are very successful and effective methods both economically and ecologically, and to use appropriate plant species in the rehabilitation areasÇalışmanın amacı: Bu çalışmada; toprak ve sedimentteki ağır metal kirliliğinin mesafeye bağlı olarak değişimi ortaya konulmaya çalışılmıştır. Çalışma alanı: Türkiye’nin Doğu Karadeniz Bölgesinde yer alan Artvin İli, Murgul İlçesi sınırları içerisinde yer alan bakır işletmesi ve güzergâhını kapsamaktadır. Materyal ve yöntem: Örnek alanlar, merkez noktası bakır işletmesi kabul edilerek atık suyun boşaltıldığı dere güzergâhı boyunca yüzeysel akış yönünde belirlenmiştir. Örneklemede toplamda 0-10 ve 10-20 cm derinlik kademelerinden 54 adet toprak ve 0-10 cm derinlik kademesinden ise 10 adet sediment örneği alınmıştır. Temel sonuçlar: Toprak ve sediment örneklerinin ağır metal analiz sonuçlarına bakıldığında özellikle kirletici kaynağa yakın alanlarda Bakır, Kurşun ve Çinko değerlerinin ortalamaları sınır değerlerin çok üzerinde olduğu ve merkez noktadan uzaklaştıkça toprak asitliğinin azaldığı tespit edilmiştir. Araştırma vurguları: Maden sahalarında yapılacak rehabilitasyon çalışmalarında ağır metallerin topraktan giderilmesine katkı yapmak üzere, hem ekonomik hem de ekolojik bakımdan oldukça başarılı ve etkin bir yöntem olan fitoremediasyon tekniklerinin araştırılması ve uygun bitki türlerinin belirlenerek kullanılması önerilmektedir.Artvin Coruh University: F10.02.0

Treatment assessment of road runoff water in zones filled with ZVI, activated carbon and mineral materials

Reducing the discharge of contaminants present in runoff water is important for a clean environment. This paper analyses field test results of three pilot-scale horizontal runoff water treatment zones filled with mixtures of zero valent iron (ZVI), activated carbon (AC), silica spongolite (SS), zeolite (Z), and limestone (LS). The investigated systems were (S1) ZVI/AC/SS, (S2) ZVI/AC/Z and (S3) ZVI/AC/LS. The efficiency of the three systems in the removal of Cd, Cu, Ni, Pb, Zn, COD and ammonium ions from runoff water was compared and the factors (temperature, pH, redox potential, hydraulic conductivity) and relationships affecting treatment effectiveness were determined. A statistical analysis of effluent contaminant concentrations and physicochemical parameters of effluent solutions included descriptive statistics, analysis of variance (ANOVA), a multidimensional analysis using a Principal Component Analysis (PCA), a factor analysis (FA) and a cluster analysis (CA). The ANOVA and cluster analyses indicated similarities between systems containing SS and LS. As a consequence, using cheaper SS can reduce investment costs. In addition, there were no significant differences between the three systems regarding Cd and Ni removal, while Cu and Pb were removed to almost 100%. The results indicate that all the tested materials supported ZVI and AC in the removal of heavy metals in a similar way. However, runoff water was enriched with nitrogen oxides and sulfates while flowing through treatment zones with SS and LS. The enrichment increased with increasing temperature and redox potential. The conducted analyses indicate that the most suitable mixture is ZVI/AC/Z. It should be emphasized that the ongoing processes (precipitation and ZVI corrosion) reduced the hydraulic conductivity of the filters up to two orders of magnitude. Expansive iron corrosion was the most limiting factor in ZVI filtration systems. In the future, applications decreasing the percentage of ZVI in the mixture are suggested.National Science Centre (Poland) grant number NN523 561638

Temperature influence on ordinary concrete modified with fly ashes from thermally conversed municipal sewage sludge strength parameters

Concrete is the most commonly used structural material, without which modern construction could not function. It is a material with a high potential to adapt to specific operating conditions. The use of this potential is made by its material modification. The aim of the performed investigations was the assessment of rational application possibilities of fly ashes from thermally conversed municipal sewage sludge as an alternative concrete admixture. A concrete mix was designed, based on the Portland cement CEM I 42.5R and containing various quantity of ash, amounting to 0–25% of cement mass. The samples were conditioned and heated in a furnace at the temperature of 300 ◦C, 500 ◦C, and 700 ◦C. Physical and chemical properties of the ashes as well as utility properties of the concrete, i.e., density, compressive strength after 28, 56, and 90 days of maturation, frost resistance, and compressive strength in high temperature were determined. The tests were performed at cubic samples with 10 cm edge. The replacement of a determined cement quantity by the fly ashes enables obtaining a concrete composite having good strength parameters. The concrete modified by the fly ashes constituting 20% of the cement mass achieved its average compressive strength after 28 days of maturation equal to 50.12 MPa, after 56 days 50.61 MPa and after 90 days 50.80 MPa. The temperature growth weakens the composite structure. The obtained results confirm the possibility of waste recycling in the form of fly ashes as a cement substitute in concrete manufacturing.This research was co-financed from EU funds, grant number POIR.04.04.00-00-0004/15

Removing heavy metals from the soil with phytoremediation

Günümüzde insan sağlığını olumsuz yönde etkileyen önemli faktörlerin başında çevresel kirlilikler gelmektedir. Hayat standartlarının artması, kentlerdeki hızlı nüfus artışı ve bunun yanında sanayinin gelişmesi ile birlikte oluşan atıklar çevreyi olumsuz yönde etkilemektedir. Endüstriyel faaliyetler sonucunda çevreye yayılan kirleticilerin giderilmesi için çeşitli yöntemler kullanılmaktadır. Bu yöntemlerin çoğunda ileri teknolojiler kullanılır. Bu ise yüksek yatırım ve işletme maliyetlerinin yanında yetişmiş eleman ihtiyacını da zorunlu kılar. Gelişmiş ülkeler bu olumsuz koşulları dikkate alarak son yıllarda diğerlerine nazaran daha çevre dostu bir arıtma sistemi olan fitoremediasyonu (bitkisel ıslah sistemleri) geliştirmişlerdir. Bitkisel ıslah olarak da bilinen fitoremediasyon ortamda bulunan kirleticilerin giderilmesinde veya etkisiz hale getirilmesinde çeşitli bitkilerin kullanılması şeklinde tanımlanmaktadır. Diğer ıslah teknolojileri ile karşılaştırıldığında fitoremediasyon; yerinde arıtım sağlaması, estetik açıdan memnun edici ve düşük maliyetli olması gibi avantajlara sahiptir. Hardal (Brassicajuncea), Kırmızı Yumak (Festucarubra), Karahindiba (Taraxacumofficinale) gibi hiperakümülatör bitkiler ağır metalleri bünyelerinde tutup gaz formuna dönüştürerek doğaya saldıkları bilinmektedir. Bu çalışmada, toprak kirliliğinin giderilmesinde kullanılabilecek fitoremediasyon teknolojisi, bitki türleri ve ülkemiz açısından uygulanabilirliği ortaya konulmaktadır.Environmental pollution is one of the most critical factors adversely affecting human health. Improvement in living standards, the rapid increase of urban populations, and widespread industrial production, all result in the generation of huge amounts of environment-polluting waste. Various methods are used to remove the pollutants generated by industrial activity but most of these methods require advanced technologies, involving a large financial investment and qualified personnel. Taking these costs and overheads into consideration, some economically developed countries have recently started working with phytoremediation (plantbased remediation) which, compared with the alternatives, is a much more environment-friendly waste treatment system. Also known as plant-based remediation, phytoremediation is defined as the use of various plants to stabilize or reduce contamination in the environment. Compared with other remediation technologies, phytoremediation offers the advantages of on-site treatment, aesthetic value, and low costs. Hyperaccumulators such as Indian Mustard (Brassica juncea), Red Fescue (Festucarubra), and Dandelion (Taraxacum officinale) are known to absorb heavy metals, releasing them into the atmosphere in the form of gas. This study examines phytoremediation technology, the plant species that could be used for this purpose, and the feasibility of using phytoremediation in Turkey

Silver nanoparticles (AgNPs) in urea solution in laboratory tests and field experiments with crops and vegetables

Nanotechnology and nanomaterials, including silver nanoparticles (AgNPs), are increas-ingly important in modern science, economics, and agriculture. Their biological activity involvesinfluencing plant health, physiological processes, growth, and yields, although they can also be toxicin the environment. A new fertiliser was made based on a urea solution with a relatively low contentof AgNPs obtained by the reduction of silver nitrate V. Laboratory tests were used to assess theeffect of a fertiliser solution containing 10 ppm AgNPs on the germination of agricultural plant seeds(barley, peas, oilseed rape) and vegetables (radish, cucumber, lettuce) and its foliar application onchlorophyll content, stomatal conductance, and seedling biomass. Field experiments were conductedto assess the effect that a foliar application of 15 ppm AgNPs in working liquid had on physiologicalplant parameters and yields of rape and cucumber. The AgNPs in the tested fertiliser reducedinfestation of the germinating seeds by pathogens and positively affected the physiological processes,productivity, and yields of plants. Plant response depended on plant species and habitat conditions.Reduced pathogen infestation of seeds, higher germination energy, increased chlorophyll content andstomatal conductance, and higher seedling masses all occurred under the influence of AgNPs, mainlyin oilseed rape and cucumber, and especially under thermal stress. The beneficial effect of AgNPson the yield of these plants occurred in years of unfavourable weather conditions. The positiveagricultural test results, especially under stress conditions, indicate that fertiliser produced withAgNPs as an ingredient may reduce the use of pesticides and highly concentrated mineral fertilisers.Such a fertiliser is fully in line with the idea of sustainable agriculture. However, research on theeffects that AgNPs and fertiliser have on the environment and humans should continue

Immobilization of potentially toxic elements (PTE) by mineral-based amendments: Remediation of contaminated soils in post-industrial sites

In many post-industrial sites, the high contents and high mobility of different potentially toxic elements (PTEs) make the soils unsuitable for effective management and use. Therefore, immobilization of PTE seems to be the best remediation option for such areas. In the present study, soil samples were collected in post-industrial areas in Northeastern Poland. The analyzed soil was characterized by especially high contents of Cd (22 mg·kg−1), Pb (13 540 mg·kg−1), and Zn (8433 mg·kg−1). Yellow lupine (Lupinus luteus L.) and two types of mineral-based amendments were used to determine their combined remediation effect on PTE immobilization. A greenhouse pot experiment was conducted to evaluate the influence of chalcedonite and halloysite on plant growth, chlorophyll a fluorescence, the leaf greenness index (SPAD), PTE uptake, and the physicochemical properties and toxicity of soil. The application of chalcedonite resulted in the greatest increase in soil pH, whereas halloysite contributed to the greatest reduction in the contents of Ni, Pb, Zn, and Cr in soil, compared with the control treatment. The addition of halloysite significantly increased plant biomass. The application of mineral-based amendments increased the ratio of variable fluorescence to maximum chlorophyll fluorescence (Fv/Fm) in yellow lupine leaves. The leaf greenness index was highest in plants growing in soil amended with chalcedonite. The results of this study suggest that mineral-based amendments combined with yellow lupine could potentially be used for aided phytostabilization of multi-PTE contaminated soil in a post-industrial area

Successful outcome of phytostabilization in Cr(VI) contaminated soils amended with alkalizing additives

This study analysed the effect of three alkalizing soil amendments (limestone, dolomite chalcedonite) on aided phytostabilization with Festuca rubra L. depending on the hexavalent chromium (Cr(VI)) level in contaminated soil. Four different levels of Cr(VI) were added to the soil (0, 50, 100 and 150 mg/kg). The Cr contents in the plant roots and above-ground parts and the soil (total and extracted Cr by 0.01 M CaCl2) were determined with flame atomic absorption spectrometry. The phytotoxicity of the soil was also determined. Soil amended with chalcedonite significantly increased F. rubra biomass. Chalcedonite and limestone favored a considerable accumulation of Cr in the roots. The application of dolomite and limestone to soil contaminated with Cr(VI) contributed to a significant increase in pH values and was found to be the most effective in reducing total Cr and CaCl2-extracted Cr contents from the soil. F. rubra in combination with a chalcedonite amendment appears to be a promising solution for phytostabilization of Cr(VI)-contaminated areas. The use of this model can contribute to reducing human exposure to Cr(VI) and its associated health risks. © 2020 by the authors.Ministerstwo Nauki i Szkolnictwa Wyższego: MNiS

Chemical composition and hazardous effects of leachate from the active municipal solid waste landfill surrounded by farmlands

Landfill leachates are potentially harmful to the environment and to human health.The objective of this study was to characterize leachates in order to analyze whether a relationshipexists between the stored waste and the composition of leachates, and to detect possible leakages ofpollutants into the environment. To achieve these objectives, field data, Global Positioning Systemdata and physico-chemical data were used. Biological tests are becoming increasingly popularin determining leachate toxicity; therefore, two toxicity tests were performed with the seeds ofwhite mustard (Sinapis albaL.) and duckweed (Lemna minorL.). Leachates were sampled from theleachate pond. Groundwater quality was monitored by using drill holes. The research and analysiscarried out are important to determine their potential impact on agricultural areas located near thelandfill. Demonstrably increased (P<0.05) concentrations of heavy metals were detected only inthe leachate pond which closes the landfill body, where it links up with the landfill insulation layer.Water sampled from drill holes reaching into groundwater was not contaminated. The results showedthat the leachates did not leak outside the landfill. Nevertheless, they were found to be phytotoxic.Both toxicity tests showed that the increasing amount of leachates resulted in the increasing growthinhibition of the tested plants. The proper handling of leachates should have been ensured.The research was funded by the Ministry of Agriculture of the Czech Republic, institutional support MZE-RO1720

Evaluation of surface water quality by using Canadian Council of Ministers of the Environment Water Quality Index (CCME WQI) method and discriminant analysis method: a case study Coruh River Basin

In this study, the water quality of the Coruh River Basin, which is located in the Eastern Black Sea Region of Turkey, was evaluated. The water quality data measurement results obtained by the State Hydraulic Works 26th Regional Directorate from four different sites over a course of 4 years between the years 2011 and 2014 in the Coruh River Basin were used as the data. In this study, the water quality was evaluated by using the Canadian Council of Ministers of the Environmental Water Quality Index (CCME WQI) method and discriminant analysis (DA). The water quality of the Coruh River Basin was calculated as 30.4 and 71.35 by using the CCME WQI and classified as "poor," "marginal," and "fair". These values show that the water of the Coruh River Basin is degraded and under threat and its overall quality is not close to natural or desired levels. The monitoring sites were divided into two groups by the cluster analysis (CA). DA is a multivariate analysis technique used to divide individuals or objects into different groups and assign them into predetermined groups. As a result of DA, calcium (Ca) and sulfate (SO4) were determined to be significant parameters in the determination of the water quality of the Coruh River Basin. The success of DA depends on the percentage of correct classification. As a result of the analysis, 23% of the parameters in the first measurement point, 69.2% of the parameters in the second and third measurement points, and 76.9% of the parameters in the fourth measurement point were classified correctly. Since the second measurement point is the discharge point of a copper mine, it can be said that the water quality parameters measured may provide accurate results in detecting pollution at this point