Soil Treatment Plant Research Articles

Growth of complete ammonia oxidizers on guanidine

Guanidine is a chemically stable nitrogen compound that is excreted in human urine and is widely used in manufacturing of plastics, as a flame retardant and as a component of propellants, and is well known as a protein denaturant in biochemistry1–3. Guanidine occurs widely in nature and is used by several microorganisms as a nitrogen source, but microorganisms growing on guanidine as the only substrate have not yet been identified. Here we show that the complete ammonia oxidizer (comammox) Nitrospira inopinata and probably most other comammox microorganisms can grow on guanidine as the sole source of energy, reductant and nitrogen. Proteomics, enzyme kinetics and the crystal structure of a N. inopinata guanidinase homologue demonstrated that it is a bona fide guanidinase. Incubation experiments with comammox-containing agricultural soil and wastewater treatment plant microbiomes suggested that guanidine serves as substrate for nitrification in the environment. The identification of guanidine as a growth substrate for comammox shows an unexpected niche of these globally important nitrifiers and offers opportunities for their isolation.

Improved Cadmium Removal Induced by Interaction of Nanoscale Zero-Valent Iron and Microplastics Debris

Nanoscale zero-valent iron (nZVI) is one of the most prevalently used engineered nanomaterials for heavy metals removal. Microplastics (MPs) have been detected extensively in the environment, such as soil, surface water, groundwater, and water treatment plant. PVC MPs and Cd coexist in a variety of environment, and Cd compounds are often used as stabilizers in PVC production, which increases the likelihood of their coexistence. In this work, the influence of aged PVC MPs on Cd2+ removal with nZVI was evaluated. Spent nZVI after reaction with Cd2+ with and without MPs was characterized with scanning transmission electron microscopy (STEM), energy-dispersive spectroscopy (EDS), scanning electron microscope (SEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectrometer (FTIR), and Brunauer-Emmett-Teller (BET). The results showed that when MPs coexisted, the removal rate of Cd2+ with nZVI increased by up to 73.4%. Spent nZVI has more extensive oxidation, and has looser structure and higher specific surface area in a mixed contamination solution with trace MPs, resulting in high removal efficiency of Cd2+. Interaction between PVC MPs and nZVI shows positive promotion toward removal of Cd2+ with nZVI; thus, nZVI may have great potential for remediation of Cd in the water environment rich in PVC MPs.

Towards quantifying microbial dispersal in the environment.

Towards quantifying microbial dispersal in the environment.

Enhancing control of multidrug-resistant plasmid and its host community with a prolonged thermophilic phase during composting.

The plasmid-mediated horizontal transfer of antibiotic resistance genes (ARGs) among bacteria facilitates the evolution and dissemination of antibiotic resistance. Broad-host-range plasmids can be transferred to different bacterial hosts in soil, plant rhizospheres, and wastewater treatment plants. Although composting is an effective way to convert organic waste into fertilizer and reduce some ARGs, few studies have focused on its effects on the spread of ARG-carrying plasmids and their bacterial host communities during composting. In this study, a fluorescently labeled Pseudomonas putida (P. putida) harboring a broad-host-range plasmid RP4 carrying three ARGs was inoculated into a raw material microcosm and composted with different durations of the thermophilic phase. The fate of the donor and RP4 in composting was investigated. The prolonged thermophilic composting removed 95.1% of dsRed and 98.0% of gfp, and it inhibited the rebound of P. putida and RP4 during the maturation phase. The spread potential of RP4 decreased from 10−4 to 10−6 transconjugants per recipient after composting. In addition, we sorted and analyzed the composition of RP4 recipient bacteria using fluorescence-activated cell sorting combined with 16S rRNA gene amplicon sequencing. The recipient bacteria of RP4 belonged to eight phyla, and Firmicutes, accounting for 75.3%–90.1%, was the dominant phylum in the transconjugants. The diversity and richness of the RP4 recipient community were significantly reduced by prolonged thermophilic periods. Overall, these findings provide new insights for assessing the contribution of composting in mitigating the dissemination of plasmid-mediated ARGs, and the prolonged thermophilic phase of composting can limit the transfer of multidrug-resistant plasmids.

Trends in Methane Fermentation Treatment System and Sludge Recycling Technology for Biomass Utilization

Recently, utilization of biomass (i.e. domestic waste, excess sludge, food processing waste, etc.) is getting an attention as a promising way to realize economical low-carbon society goal. This paper provides a summary of current trends in biomass utilization regarding methane fermentation and sludge recycling technology. Methane fermentation is the process involved the conversion of organic waste to methane gas, which is being used for electricity generation and as fuel. As a plentiful of excess sludge is generated from sewage and night soil treatment plants daily, the recycle technology for biomass utilization is developed. For example; excess sludge and night soil are efficiently dewatered by shaft sliding screw press (to achieve 70% or lower moisture content) and utilized as a combustion improver. In addition, phosphorus in the thickening filtrate generated from the dewatering system is recovered through phosphorus recovery system and utilized as an agricultural fertilizer.

Results and prospects for the development of scientific research in FSBSI FSVC

The article reflects the issues of the current state of scientific research at the FSBSI FSVC, shows the directions and prospects for the development of selection and seed production of vegetable crops. The main mission of the selection and seed-growing work of the FSVC is the creation and reproduction of varieties and hybrids of vegetable and melon crops of a new generation, characterized by resistance to abiotic and biotic stressors, high productivity and product quality. One of the main ways to increase the efficiency of the breeding process is the use of modern methods of biotechnology and molecular genetics, which make it possible to obtain new genotypes and reduce the time of breeding. Success has been achieved in the creation of homozygous lines of cabbage, squash, cucumber, carrots. For the first time, it was possible to complete a full cycle of obtaining doubled radish haploids in microspore culture in vitro. The institution pays special attention to immunological research on the resistance of crops and new varieties to diseases, as well as protecting plants from pests and diseases. Phytosanitary monitoring, assessment and selection of resistant genotypes are carried every years. One of the important theoretical and practical problems solved at the institution is the development of environmentally friendly products based on preparations obtained from plants with a high content of biologically active compounds with adaptogenic properties. In the center, a new direction of research in traditional breeding has received significant development - the creation of varieties of vegetable plants with an increased content of biologically active substances and antioxidants, on the basis of which functional products are created. The persistence of modern varieties and hybrids of table carrots, depending on the biochemical composition, has been studied. Methods for enriching vegetable plants with micronutrients are being developed. A large amount of scientific research is being carried out on the development of technologies for the cultivation of new varieties and hybrids, as well as technologies for their seed production. At the branches located in different soil and climatic conditions, hospitals were established to study the interaction of factors controlling soil fertility and the productivity of vegetable crops in agrocenoses (crop rotation, soil treatment systems, fertilizers and plant protection). In general, at the FSBSI FSVC, all research is aimed at developing and improving methods in breeding and seed production of vegetable crops, creating new breeding achievements and developing varietal technologies for their cultivation.

A Case Study on UAV-assisted Construction Surplus Soil Treatment Plant Management in Taiwan

Construction surplus soil tracking management has been the key management issue in Taiwan since 1991. This is mainly due to the construction surplus soils were often regarded as disposable waste and were disposed openly without any supervision, leading to environmental pollution. Even though the surplus soils were gradually being viewed as reusable resources, some unscrupulous enterprises still dump them freely for their own convenience. In order to dispose these surplus soils, site offices are required to confirm with the soil treatment plant regarding the approximate soil volume for hauling vehicle dispatch. However, the excavated soil volume will transform from bank volume to loose volume upon excavation, which may differ by a certain speculative coefficient (1.3), depending on the excavation site and geological condition. For managing and tracking the construction surplus soils, local government authorities frequently performed plant site spot check, but the lack of rapid assessment tools for soil volume estimation increased the evaluation difficulty for plant site inspectors. This study adopted unmanned aerial vehicle (UAV) in construction surplus soil tracking and rapidly acquired plant site photography and point cloud data, the excavated soil volume can be determined promptly after post-processing and interpretation, providing references to future surplus soil tracking management.

Feasibility Study on UAV-assisted Construction Surplus Soil Tracking Control and Management Technique

Construction surplus soil tracking management has been the key management issue in Taiwan since 1991. This is mainly due to the construction surplus soils were often regarded as disposable waste and were disposed openly without any supervision, leading to environmental pollution. Even though the surplus soils were gradually being viewed as reusable resources, some unscrupulous enterprises still dump them freely for their own convenience. In order to dispose these surplus soils, site offices are required to confirm with the soil treatment plant regarding the approximate soil volume for hauling vehicle dispatch. However, the excavated soil volume will transform from bank volume to loose volume upon excavation, which may differ by a certain speculative coefficient (1.3), depending on the excavation site and geological condition. For managing and tracking the construction surplus soils, local government authorities frequently performed on-site spot check, but the lack of rapid assessment tools for soil volume estimation increased the evaluation difficulty for on-site inspectors. This study adopted unmanned aerial vehicle (UAV) in construction surplus soil tracking and rapidly acquired site photography and point cloud data, the excavated soil volume can be determined promptly after post-processing and interpretation, providing references to future surplus soil tracking management.

Higher alkyl sulfatase activity required by microbial inhabitants to remove anionic surfactants in the contaminated surface waters.

Biodegradation of anionic surfactants, like sodium dodecyl sulfate (SDS) are challenged by some bacteria through the function of the enzyme alkyl sulfatases. Therefore, identifying and characterizing bacteria capable of degrading SDS with high alkyl sulfatase enzyme activity are pivotal. In this study, bacteria isolated from surfactant contaminated river water were screened for their potential to degrade SDS. Primary screening carried out by the conventional enrichment culture technique and assessment of SDS-degrading ability through methylene blue active substance assay revealed 12, out of 290, SDS-degrading surface water bacteria with maximum SDS degrading abilities of 46-94% in 24-54 h. The isolates exhibited optimum growth at SDS concentration of 1 g/L, but tolerated up to 15-75 g/L. Eleven isolates were identified as the species of Pseudomonas and one isolate was identified as Aeromonas through 16S rRNA sequencing. Proteolytic activity of alkyl sulfatases in the identified isolates was shown by using native-PAGE analysis. The determined enzyme activities changed in between 1.32 and 2.90 U/mg in the crude extracts. Preliminary experiments showed that the isolates with the alkyl sulfatase enzyme activities ≥2.50 U/mg were strong gratuitous degraders. However, their relative importance in soil, sewage, and wastewater treatment plants remains to be assessed.

薬剤と微生物処理を併用したし尿汚泥の減量化技術の開発

新規に開発した汚泥減量化システムについて，し尿処理場への適用を検討した。本減量化システムは化学処理と微生物処理を組み合わせたもので，第1段階ではアルカリ処理によって減量化され，後段の微生物処理によってさらなる減量化が進行する。2か所のし尿処理場より採取した汚泥について，まずアルカリ回分処理により，その減量化特性を評価した。次に，微生物処理も組み合わせた連続処理を実施し，30～50 %の汚泥減量化率が得られた。この結果は，本技術のし尿処理場への適用可能性を示唆するものと考えられた。

Progressive Plant Extension Applied to the Soil Treatment Facility of the “Arge Ground Unit”, Particularly Enhancement of the Treatment Range and Optimization of the Product Flows: An Example for Successful Urban Mining

The wet-mechanical soil treatment plant (soil washing plant) of the consortium “Arge Ground Unit”, located at the industrial area Linz (Upper Austria), was extended progressively. Particular mineral processing techniques were applied for the enrichment of contaminants and a continuous optimization process was implemented, pertaining all material flows from coarse gravel fraction to filter cake. Considerable quality control improvement and cost reduction were achieved by optimizing the wet-mechanical soil treatment plant. Particularly the disintegration and pre-separation of low-density material from the contaminated input material, the efficiency of the process water cycle and the decontamination of the sand fraction 0/4 mm were improved significantly in regard to higher PAH-contaminated material from the high priority remediation site ‘Cookery Linz (O76)’. In addition, flotation tests were performed with contaminated sand and dewatered filter cake, which finally led to the final extension step of integrating a two-step froth floatation unit into the existing plant concept for the treatment of the highly-contaminated thickener sludge. Owing to the plant expansion, the CO2 reduction within the operation period of 2009–2015 was in a considerable range of 2,280 metric tons. The current status and insights gained are subject of this technical note.

PRELIMINARY STUDIES OF BENZOTHIAZOLE AND BENZOTRIAZOLE MICROBIOLOGICAL DEGRADATION BY ACTIVATED SLUDGE ISOLATES

Benzothiazoles (BTs) and benzotriazoles (BTAs) are aromatic heterocyclic compounds which have been detected in aquatic environment, soil and wastewater treatment plants. These compounds demonstrate toxicity towards activated sludge microorganisms, as well as towards higher organisms, thus they are regarded as a threat to biological wastewater treatment. Studies performed on activated sludge as a mixed culture show that the transformation of BTs and BTAs is possible, in some cases also biologically. In this experiment it was revealed that BTA is degraded more easily and more efficiently than BT by activated sludge isolates. The decrease in the concentration of these compounds was not drastic but none of the isolated cultures were enriched or prepared to such a process performance. As a confirmation of these studies the next step in the analysis should be the culture pre-treatment (such as enrichment) or cometabolic degradation together with a more easily degradable carbon source.

Abundance and diversity of ammonia-oxidizing archaea in response to various habitats in Pearl River Delta of China, a subtropical maritime zone

Ammonia-oxidizing archaea (AOA) are widely considered key to ammonia oxidation in various environments. However, little work has been conducted to simultaneously investigate the abundance and diversity of AOA as well as correlations between archaeal amoA genotypes and environmental parameters of different ecosystems at one district. To understand the abundance, diversity, and distribution of AOA in Pearl River Delta of China in response to various habitats, the archaeal amoA genes in soil, marine, river, lake, hot spring and wastewater treatment plant (WWTP) samples were investigated using real-time fluorescent quantitative PCR and clone libraries. Our analyses indicated that the diversity of AOA in various habitats was different and could be clustered into five major clades, i.e., estuary sediment, marine water/sediment, soil, hot spring and Cluster 1. Phylogenetic analyses revealed that the structure of AOA communities in similar ecological habitats exhibited strong relation. The canonical correspondence method indicated that the AOA community structure was strongly correlated to temperature, pH, total organic carbon, total nitrogen and dissolved oxygen variables. Assessing AOA amoA gene copy numbers, ranging from 6.84 × 106 to 9.45 × 107 copies/g in dry soil/sediment, and 6.06 × 106 to 2.41 × 107 copies/L in water samples, were higher than ammonia-oxidizing bacteria (AOB) by 1–2 orders of magnitude. However, AOA amoA copy numbers were much lower than AOB in WWTP activated sludge samples. Overall, these studies suggested that AOA may be a major contributor to ammonia oxidation in natural habitats but play a minor role in highly aerated activated sludge. The result also showed the ratio of AOA to AOB amoA gene abundance was positively correlated with temperature and less correlated with other environmental parameters. New data from our study provide increasing evidence for the relative abundance and diversity of ammonia-oxidizing archaea in the global nitrogen cycle.

High-Throughput Analysis of Ammonia Oxidiser Community Composition via a Novel, amoA-Based Functional Gene Array

Advances in microbial ecology research are more often than not limited by the capabilities of available methodologies. Aerobic autotrophic nitrification is one of the most important and well studied microbiological processes in terrestrial and aquatic ecosystems. We have developed and validated a microbial diagnostic microarray based on the ammonia-monooxygenase subunit A (amoA) gene, enabling the in-depth analysis of the community structure of bacterial and archaeal ammonia oxidisers. The amoA microarray has been successfully applied to analyse nitrifier diversity in marine, estuarine, soil and wastewater treatment plant environments. The microarray has moderate costs for labour and consumables and enables the analysis of hundreds of environmental DNA or RNA samples per week per person. The array has been thoroughly validated with a range of individual and complex targets (amoA clones and environmental samples, respectively), combined with parallel analysis using traditional sequencing methods. The moderate cost and high throughput of the microarray makes it possible to adequately address broader questions of the ecology of microbial ammonia oxidation requiring high sample numbers and high resolution of the community composition.

Effect of Dose-Response of Zinc and Manganese on Siderophores Production

Problem statement: This study was conducted to find and determine whether the siderophores of the four environmental Pseudomonas spp. isolates possess a sequestering activity towards essential transition metals (Zn and Mn) other than iron. Approach: Four fluorescent Pseudomonads isolated from various environments, were characterized analytically (Isoelectric focusing), biologically (pyoverdine-mediated uptake) and genetically (16S rDNA sequencing). By means of spectrophotometric measurements, it was possible to establish and compare the levels of pyoverdine production, in two different nutrient-poor media. Results: The strains were assigned, by sequencing, to P. fluorescens, P. aeruginosa, P. putida and P. mosselii isolated, respectively from soil, compost, sea water and waste water treatment plant. These bacterial strains were recognized as producing diver’s yellow-green siderophores types, when grown under conditions of iron starvation. The highest metabolite concentration was obtained with PsC132 and PsTp171 strains isolated respectively from compost and waste water treatment plant, in CAA medium. Strains grown in CAA medium exhibit a higher PVD level compared to SM medium. Mn (II) was found to promote pyoverdine biosynthesis, but rather, Zn (II) had no significant effect on siderophore production when compared to control medium. For both strains PsS29 and PsC132, the increase of iron concentration quenched siderophore production especially above 20 μM. Pyoverdine level declined with the high concentration of zinc but increased with Manganese concentration ranging up to 70 μM (in case of PsC132) and 300 μM (in case of PsS29). Conclusion/Recommendations: The ability of fluorescent Pseudomonas, isolated from wastewater treatment plant and from compost, to sequester zinc, point to a unique advantage of these species for divers bioremediation applications.

Emission of Nitrous Oxide from the Reaction Chambers of the Night Soil Treatment Plants of High Loading Type

Emission of Nitrous Oxide from the Reaction Chambers of the Night Soil Treatment Plants of High Loading Type

Exhaust gas components of night soil treatment plant by Zimmerman Process

Exhaust gas components of night soil treatment plant by Zimmerman Process

Emission and Control of Nitrous Oxide from Nitrification and Denitrification in A Night Soil Treatment Plant Employing Intermittent Aeration

Emission and Control of Nitrous Oxide from Nitrification and Denitrification in A Night Soil Treatment Plant Employing Intermittent Aeration

Characterizing the Oxygen Isotopic Composition of Phosphate Sources to Aquatic Ecosystems

The oxygen isotopic composition of dissolved inorganic phosphate (delta18Op) in many aquatic ecosystems is not in isotopic equilibrium with ambient water and, therefore, may reflect the source delta18Op. Identification of phosphate sources to water bodies is critical for designing best management practices for phosphate load reduction to control eutrophication. In order for delta18Op to be a useful tool for source tracking, the delta18Op of phosphate sources must be distinguishable from one another; however, the delta18Op of potential sources has not been well characterized. We measured the delta18Op of a variety of known phosphate sources, including fertilizers, semiprocessed phosphorite ore, particulate aerosols, detergents, leachates of vegetation, soil, animal feces, and wastewater treatment plant effluent. We found a considerable range of delta18Op, values (from +8.4 to +24.9 per thousand) for the various sources, and statistically significant differences were found between several of the source types. delta18Op measured in three different fresh water systems was generally not in equilibrium with ambient water. Although there is overlap in delta18Op values among the groups of samples, our results indicate that some sources are isotopically distinct and delta18Op can be used for identifying phosphate sources to aquatic systems.

Study of biodiversity of Klebsiella sp.

Microorganisms provide the largest gamut of genetic and physiological diversity in nature. The determination of the biodiversity of microbes is necessary for the exploitation of their inestimable population, which remains unexplored in the environment. In our study, we have isolated 20 different Klebsiella sp. from contaminated soil and effluent treatment plants and determined their genetic diversity using molecular tools. The phylogenetic result based on 16S rDNA sequencing, shows genetic variation among the strains, which was further confirmed by Randomly Amplified Polymorphic DNA (RAPD) analysis. The occurrence of a broad spectrum of Klebsiella sp. variants in polluted and stress environments portrays the ability of this genus to survive abundantly under stress conditions.