Reuse Options Research Articles

Evaluation of a New Electrochemical Concept for Vacuum Toilet Wastewater Treatment - Comparison with Ozonation and Perozone Processes

Over the last several years, the removal of more than 150 micropollutants was investigated. Many pharmaceuticals are persistent and pass the conventional wastewater treatment plants (WWTP). According to literature, the removal efficiency of various pharmaceuticals is between 0 and 50 % in activated sludge processes. For a standard analgesic such as Diclofenac, the removal efficiency is approx. 30 %. Therefore, additional treatment such as 4th treatment step is necessary, which is already implemented in some WWTPs in Europe, to save water bodies as much as possible. Options for the 4th treatment step are, for example, activated carbon adsorption, nanofiltration and advanced oxidation processes (AOP). By far one of the most cost efficient AOP is the ozonation. However, it is not able to remove X-ray contrast media sufficiently. For this purpose, electrochemical oxidation processes (EAOP) based on boron-doped diamond electrodes are much more effective. Keeping in mind that AOPs are still an emerging technology, especially for water reuse options and also might cause even toxic intermediates, one of the biggest disadvantages are the relatively high operational costs due to the electrical energy demand. Especially electrochemical reactors, which are based on two boron-doped diamond (BDD) electrodes are very cost-intensive, particularly in comparison to ozonation or perozone (ozone plus peroxide) processes. For that reason, a new electrochemical reactor concept, which promises lower CAPEX and OPEX costs, was investigated. This reactor concept consists mainly of one BDD electrode as anode and a gas diffusion electrode (GDE) as cathode. The innovative reactor concept combines the generation of highly reactive hydroxyl radicals on the anode surface and simultaneously hydrogen peroxide on the cathode surface, which is very efficient as there is a double use of the same applied power. Both electrodes are mounted in a membrane-less flow-through reactor in pilot-scale for direct treatment of wastewater. Due to the direct contact between the surfaces of both electrodes, the wastewater gets treated specifically, which leads to a high energy efficiency. First results already prove the more energy efficient removal of COD in an artificial wastewater with the new reactor concept. For a detailed evaluation, a defined artificial wastewater with compounds and concentration equal to vacuum toilet wastewater was treated by the new reactor concept as well as by ozonation and perozone process (ozone plus peroxide). COD removal as well as the associated energy demand were measured after defined intervals in each step of the treatment to determine the performance of the different processes. A comparison was made between the different kind of treatments (EAOP, ozonation, perozone) concerning COD degradation and the power demand. The evaluation is based on electrical energy per order (EEO) conception as well as degradation for given reaction kinetics.

Nitrogen Recovery With Source Separation of Human Urine—Preliminary Results of Its Fertiliser Potential and Use in Agriculture

The growing demand for food and the increasing costs of cultivation are posing a challenge for agriculture. Diminishing phosphorus reserves, as well as the energy intensive method of producing nitrogen fertilisers are drivers for more intensive reuse of different organic fertilisers, such as manures and excreta. Source separation and fertilisation with human urine can be one option for nutrient reuse. Urine contains all the main nutrients as well as micronutrients in soluble form, but it also contains chemicals, like pharmaceuticals and hormones. The aim of this study was to examine the efficiency and safety of the use of source separated human urine as a fertiliser for barley (Hordeum vulgare). The fertiliser efficiency of source-separated urine was examined in field-scale experiments for the first time in Finland. Two separate cultivation experiments in two fields and barley varieties were conducted. The efficiency of urine as a fertiliser was compared to corresponding amount of mineral fertiliser. No fertilizer was applied to one plot in order to create a reference treatment. The two experiments were conducted using variety Wolmari with 54 kg N ha-1 and variety Harbinger with 100 kg N ha-1. The barley grain and straw yield grown with urine fertiliser was equivalent to the yield in mineral fertilised plots. The growth of barley in both fertiliser treatments was slightly faster, compared to non-fertilised treatment. There were no significant differences between the treatments in terms of protein content of the grain although the results varied in terms of the thousand grain weight (TGW) and germination. The urine analyses indicated that there were no pathogen indicators, nor heavy metal concentrations, exceeding the limit values set by legislation. The main nutrient concentrations (N, P, K) would also meet the requirements for a fertiliser product according to Finnish legislation. Pharmaceuticals and hormones were found from the urine, but apart from progesterone, all of them presented extractable values in soil below the detection limits, and they were not detected in measurable amounts in barley grain at the end of the growing season. These results suggest that source separated urine could be an efficient fertiliser in crop cultivation.

Performance of a small-scale wastewater treatment plant for removal of pathogenic protozoa (oo)cysts and indicator microorganisms

ABSTRACTThe protozoa Giardia and Cryptosporidium are associated with numerous outbreaks of waterborne diseases worldwide. This study aimed to evaluate the concentration of Giardia spp. cysts, Cryptosporidium spp. oocysts, total coliforms, Escherichia coli and Clostridium perfringens in raw wastewater and their removals at UASB reactor, activated sludge system (operated conventionally and extended aeration) and slow sand filtration. Giardia spp. cysts were present in 100% and Cryptosporidium spp. oocysts in 31.4% of the analysed wastewater samples. The UASB reactor followed by activated sludge system obtained approximately 2.0 log of removal for total coliforms and E. coli, whereas for C. perfringens and Giardia spp. cysts, it obtained 1 log. There was a high percentage of (oo)cysts still viable after secondary treatment, therefore, the risk of contamination of water courses and, consequently, for public health is considerable. However, after tertiary filtration, no (oo)cysts were found in any of the filtered effluent samples, being a good option for future reuse. Seasonal variations did not affect the concentrations and removals of microorganisms observed. Lack of correlations of concentrations of indicator microorganisms and (oo)cysts raise caveats and doubts regarding the true microbiological quality when using only indicator microorganisms.

Disclosing water-energy-economics nexus in shale gas development

Shale gas has gained importance in the energy landscape in recent decades. However, its development has raised environmental concerns, especially, those associated with water management. Thus, the assessment of water management aspects, which inevitably impact the economic aspects, is crucial in evaluating the merits of any project exploiting this energy source. This paper provides a review of the economic and environmental implications of shale gas development around the world. Furthermore, to demonstrate the interplay between the various technical, environmental and economic factors in concrete terms, we report on a specific set of case studies conducted using an integrated decision-support tool that has been implemented to model and optimize shale gas development projects. The case study results confirm that the gas breakeven price decreases with expansion in scale of the shale gas development, i.e. increasing the number of well-pads in the system. However, scale also increases the options for water re-use and recycle in drilling and fracturing operations, which can result in lower freshwater withdrawal intensity. Moreover, under water scarcity scenarios, the choice of well-pad designs that are inherently less water intensive was found to be more cost-effective than water re-use or/and recycle strategies at reducing net freshwater demand. Similar trends were observed when the impact of wastewater quality, i.e. total dissolved solids concentration, on the optimal development strategy of shale gas plays was investigated. The results of these case studies reveal that greater efforts are needed at characterizing freshwater availability and wastewater quality for the evaluation of both the economic and environmental aspects of shale gas development.

A statistical approach of zinc remediation using acidophilic bacterium via an integrated approach of bioleaching enhanced electrokinetic remediation (BEER) technology

The aim of the present study was to isolate an indigenous acidophilic bacterium from tannery effluent contaminated sludge (TECS) sample and evaluate its potentiality towards the removal of zinc using an integrated approach of bioleaching enhanced electrokinetic remediation (BEER) technology in zinc spiked soil at an initial concentration of 1000 mg/kg. The isolated acidophilic bacterium was characterized by biochemical and 16S rRNA molecular identification and was named as Serratia marcescens SMAR1 bearing an accession no. MG742410 in NCBI database. The effect of pH and inoculum dosage of SMAR 1 strain showed an optimal growth at pH 5.0 and 4% (v/v) respectively. Based on these experimental data, a statistical analysis was done using Design Expert computer software, v11 to study the interaction between the process parameters with respect to zinc reduction as an output response. Electrokinetic experiments were conducted in a customised EK cell under optimised process conditions, employing titanium electrodes. Experiments for zinc removal were demonstrated for bioleaching, electrokinetic (EK) and BEER technology. On comparing, the integrated process was found to evidence as an excellent metal remediation option with a maximum zinc removal of 93.08% in 72 h than plain bioleaching (72.86%) and EK (56.67%) in 96 h. This is the first report of zinc removal in a short period of time using Serratia marcescens. It is therefore concluded that the BEER approach can be regarded as an effective technology in cleaning up the metal contaminated environment with an easy recovery and reuse option within short period of time.

Sustainable practice for the food industry: assessment of selected treatment options for reclamation of washwater from vegetable processing

Water reclamation has become a feasible option due to water scarcity in many regions of the USA. Industrial fresh produce processing wastewater streams usually do not actively employ water recycling despite the large quantities of water being consumed. Further, there is a paucity of information on water reuse options for this sector. Therefore, this study assessed selected treatment processes for washwater from vegetable processing. The work focused on turbidity, chemical oxygen demand, dissolved organic carbon at ambient and low-temperature vegetable processing environments (4 °C). Microfiltration, ultrafiltration, reverse osmosis, and novel biocatalyst composites were evaluated using both synthetic washwater and composite washwater samples collected from a commercial produce processing plant. Results showed that ultrafiltration and microfiltration were able to substantially reduce turbidity, but achieved only minimal chemical oxygen demand and dissolved organic carbon reduction. A majority of the constituents contributing to these two parameters were dissolved compounds, causing challenges for physical separation treatment techniques. The biocatalyst system demonstrated good efficiency at both 22 and 4 °C, with respect to the removal of chemical oxygen demand (72 and 66%, respectively), and dissolved organic carbon (74 and 70%, respectively). Reverse osmosis generated high-quality water that could be employed in vegetable production line; however, extensive pretreatment processes were required. This study demonstrated the potential to recover washwater in produce processing industry. Moreover, the results showed that the biocatalyst treatment could be applied at low temperature and potentially applied to water recycling schemes for wastewater streams from food industries that operate under low operating temperatures.

Repurposing end of life notebook computers from consumer WEEE as thin client computers – A hybrid end of life strategy for the Circular Economy in electronics

Abstract This paper presents an investigation into the feasibility of repurposing end-of-life notebook computers as thin client computers. Repurposing is the identification of a new use for a product that can no longer be used in its original form and has the potential to become a hybrid re-use/recycling end-of-life strategy for suitable e-waste when direct reuse is not economically or technically feasible. In this instance, it was targeted to produce thin client computers using motherboards, processors and memory from used laptops while recycling all other components. Notebook computers are of interest for this type of strategy due to having a substantial environmental impact in manufacturing but often not having the option of direct reuse as they are prone to damage and experience a rapid loss of value over time. They also contain multiple critical raw materials with very low recycling rates. The notebook computers were sourced from Civic Amenity sites (CA) and originated from business-to-consumer (B2C) channels. A total of 246 notebook computers were collected and analysed. The paper outlines a methodology developed to identify, test, analyse, and disassemble suitable devices for repurposing. The methodology consists of the following stages with associated pass rates; Visual Inspection & Power-on Test (32%) the Initial-stage functionality test comprised of Functionality Test (56%), Diagnostics (100%) and Benchmarking (86%). The Disassembly stage had a pass rate of 100% and the Post-Disassembly Test comprised of a Validation test (86%). The Final-stage functionality test had a pass rate of 61%. The overall results show that 9% of the notebook computers were suitable for repurposing as thin client computers. It recommends the following design changes to notebooks/laptops that would support repurposing; 1) PCB mounted Fan and Heatsink assembly, 2) Eliminate daughter and I/O boards, 3) A separate Power Button assembly, 4) Reduction in size of the motherboards surface area or physical size. These design changes would allow for a more efficient transition for a change of role. A streamlined lifecycle analysis based on Cumulative Energy Demand (CED) was undertaken to compare the impact of repurposed notebook computers with new thin client computers. The results indicated that there are significant potential savings to be made by extending lifetimes and offsetting the production of new thin client computers under a range of assumptions.

Investigating calcined filter backwash solids as supplementary cementitious material for recycling in construction practices

Backwashing of filter beds in the water treatment plant produces a large volume of spent filter backwash water containing finer solid particles as waste/residue. In this study, solids present in the spent filter backwash water have been collected, processed, and calcined at 800 °C to prepare calcined filter backwash solids (CFBS) and investigated for its potential utilization as supplementary cementitious material in construction industry. Up to 20% replacement of 43 grade ordinary Portland cement, the cement-CFBS mixture complies the Indian standard specification required for construction. The study concludes that WTS obtained from filtration units in the form of CFBS is one of the best sustainable and beneficial reuse options.

Comparative life cycle sustainability assessment of urban water reuse at various centralization scales

Population growth and urbanization lead to increasing water demand, putting significant pressure on natural water sources. The rising amounts of domestic wastewater (WW) in urban areas may be treated to serve as an alternative water source that may alleviate this pressure. This study examines sustainability of utilizing reclaimed domestic wastewater in urban households for toilet flushing and garden irrigation. It models a city characterized by water scarcity, using a coal-based electricity mix. Four approaches were compared: (0) Business-as-usual (BAU) alternative, where the central WW treatment plant effluent is discharged to nature; (1) central WW treatment and urban reuse of the effluent produced; (2) semi-distributed greywater treatment and reuse, at cluster scale; (3) Distributed greywater treatment and reuse, at building scale. Environmental life cycle assessment (LCA), social LCA (S-LCA), and life cycle costing (LCC) were applied to the system model of the above scenarios, with seawater desalination as the source for potable water. System boundaries include water supply, WW collection, and treatment facilities. Analytical hierarchy process (AHP), a multi-criteria decision analysis (MCDA) methodology, was integrated into the life cycle sustainability assessment (LCSA) framework as a means for weighting sustainability criteria through judgment elicitation from a panel of 20 experts. Environmentally and socially, the two distributed alternatives perform better in most impact categories. Socially, semi-distributed (cluster scale) reuse is somewhat advantageous over the fully distributed alternative (building scale), due to the benefits of community engagement. Economically, the cluster-level scenario is the most preferable, while the building-scale scenario is the least preferable. A hierarchical representation of the problem’s criteria was constructed, according to the principals of AHP. Each criterion was weighted and those of extreme low importance were eliminated, while maintaining the integrity of the experts’ judgments. Weighted and aggregated sustainability scores revealed that cluster level reclamation, under modeled conditions, is the most sustainable option and the BAU scenario is the least sustainable. The other two alternatives, centralized and fully distributed reclamation, obtained similar intermediate scores. Distributed urban water reuse was found to be more sustainable than current practice. Different alternative solutions are advantageous in different ways, but overall, the reclamation and reuse of greywater at the cluster level seems to be the best option among the three reuse options examined in this assessment. AHP proved an effective method for aggregating the multiple sustainability criteria. The hierarchical view maintains transparency of all local weights while leading to the final weight vector.

Re-reuse of regenerated brownfields: Lessons from an Eastern European post-industrial city

Abstract Brownfields constitute a substantial portion of the land area in post-industrial cities. Many brownfields have been regenerated for various uses, addressing a range of extant problems in urban areas. However, re-use plans for current brownfields are driven by market demand and public sector prioritization and do not always meet the requirements of local residents and visitors. In this paper, we investigate how a range of brownfields re-use options are perceived by residents and visitors to the Landek area in the city of Ostrava (Czech Republic). By analysing the results of the questionnaire survey (n = 180) we found that future brownfields uses such as culture/sport and children's park are the most popular options. We found that gender was a statistically significant predictor of preferred reuse options. Women are strong supporters of the above-mentioned re-use options, while men tend to favour re-use options which promote industry. Remarkably, respondents, in general, lacked concrete ideas concerning alternative re-use options of brownfields, suggesting that professional urban planners can be of assistance in the planning of the future use of brownfield sites.

REUSE OF A CLOSED LANDFILL SITE FOR INSTALLATION AND OPERATION OF A BIOMASS UTILIZATION PLANT

The professional management of landfills during operation and after landfill capping is an important task to prevent environmental impacts. Landfill maintenance after closure can become economically favourable if landfill sites can be reused. Several approaches and experiences for reuse of capped landfills exist for example in livestock farming or installation and operation of solar power plants. Also the utilization for spare time activities after green capping and recreation or the industrial reuse for the development of a waste utilization plant is a common practice in Europe. The feasibility of reuse options depend on the site conditions including size and location of the landfill, the climatic conditions and the interests of the involved stakeholders. For the urban landfill site Gò Cát in Ho Chi Minh City (HCMC) experts from Germany and Vietnam developed a variant assessment for the preferred reuse options. One of three investigated options is considering the reuse of the landfill site for the development of a biomass utilization plant. In terms of the above described approach for Gò Cát the landfill operator is strongly involved in the landfill closure and long term maintenance works (leachate treatment, landfill gas utilization). Moreover, the operator can reuse the landfill site for an additional or new business. The design and operation criteria for the biomass utilization plant and best practice examples are presented. Beside the economic evaluation results of water and landfill gas balance will be discussed.

Optimal heat pump integration in industrial processes

Among the options for industrial waste heat recovery and reuse which are currently discussed, heat pumping receives far less attention than other technologies (e.g. organic rankine cycles). This, in particular, can be linked to a lack of comprehensive methods for optimal design of industrial heat pump and refrigeration systems, which must take into account technical insights, mathematical principles and state-of-the-art features. Such methods could serve in a twofold manner: (1) in providing a foundation for analysis of heat pump economic and energetic saving potentials in different industries, and further (2) in giving directions for experimentalists and equipment manufacturers to adapt and develop heat pump equipment to better fit the process needs.This work presents a novel heat pump synthesis method embedded in a computational framework to provide a basis for such analysis. The superstructure-based approach is solved in a decomposition solution strategy based on mathematical programming. Heat pump features are incorporated in a comprehensive way while considering technical limitations and providing a set of solutions to allow expert-based decision making at the final stage.Benchmarking is completed by applying the method on a set of literature cases which yields improved-cost solutions between 5% and 30% compared to those reported previously. An extended version of one case is presented considering fluid selection, heat exchanger network (HEN) cost estimations, and technical constraints. The extended case highlights a trade-off between energy efficiency and system complexity expressed in number of compression stages, gas- and sub-cooling. This is especially evident when comparing the solutions with 3 and 5 compression stages causing an increase of the COP from 2.9 to 3.1 at 3% increase in total annualized costs (TAC).

Characterization and constructive utilization of sludge produced in clari-flocculation unit of water treatment plant

All water treatment plants produce waste/residue amid the treatment of raw water. This study selectively investigates the clariflocculator sludge for its physicochemical characteristics and potential reuse options. Sieve analysis, XRF, SEM, XRD, FTIR, and TG-DTA instrumental techniques have been used to characterize the sludge sample. Results show that clariflocculator sludge contains about 78% fine sand having grain size range 150–75 μm. SiO2, Al2O3, Fe2O3 and CaO constitute the maximum percentage of chemical compounds present in the sludge and quartz is the main crystalline phase of the sludge. Recycling and reuse of this sludge, especially, as fine sand in preparing mortar, concrete mix and other civil engineering products would pave the way for constructive utilization with safe and sustainable sludge management strategies.

Phytoremediated marine sediments as suitable peat-free growing media for production of red robin photinia (Photinia x fraseri)

Sediments dredged by an industrial port, slightly contaminated by heavy metals and petroleoum hydrocarbons, were phytoremediated and used as peat-free growing media for the red robin photinia (Photinia x fraseri L.). Plants were grown on sediment only (S), sediment mixed with composted pruning residues (S + PR), sediment fertilized with controlled release fertilizers (S + F) and peat-based growing media as control (C). Plant elongation and dry weight, leaf contents of chlorophyll, malondialdehyde (MDA), macronutrients and heavy metals were determined at the end of one growing season. Environmental impact related to the use of sediment-based as compared to peat-based growing media was assessed by the Life Cycle Analysis (LCA). Sediment-based growing media presented significantly higher bulk density, pH and electrical conductivity values, lower C and N contents, and significantly higher total and available P. Red robin photinia grown on S + F growing media showed morphological and chemical parameters similar to those of control plants (C), whereas plants grown on S and S + PR showed lower growth. Leaf concentration of nutrients and heavy metals varied depending on the considered element and growing media, but were all within the common values for ornamental plants, whereas the highest MDA concentrations were found in plants grown on traditional growing media. The LCA indicated the use of sediments as growing media reduced the C footprint of ornamental plant production and the contribute of growing media to the environmental impact per produced plant. We concluded that sediments phytoremediation and use in plant nursery is a practical alternative re-use option for dredged sediments.

Phytoextraction of rhenium by lucerne (Medicago sativa) and erect milkvetch (Astragalus adsurgens) from alkaline soils amended with coal fly ash

Coal fly ash (CFA) is an industrial waste generated in huge amounts worldwide, and the management of CFA has become an environmental concern. Recovery of valuable metals from CFA is one of the beneficial reuse options of CFA. Rhenium (Re) is one of the rarest metals in the Earth's crust and one of the most expensive metals of strategic significance in the world market. A CFA at the Jungar Thermal Power Plant, Inner Mongolia, China, contains more Re than two alkaline soils in the surrounding region. Pot experiments were undertaken to grow lucerne (Medicago sativa) and erect milkvetch (Astragalus adsurgens) in a loessial soil and an aeolian sandy soil amended with different rates (5%, 10%, 20%, and 40%) of CFA. The results show that plant growth was considerably enhanced and Re concentration in plants was significantly increased when CFA was applied to the alkaline soils at rates of ≤20%; while in some cases plant growth was also markedly enhanced by the 40% CFA treatment, which increased plant Re concentration the most of all treatments. Both lucerne and erect milkvetch showed potential for phytoextracting Re from CFA-amended alkaline soils. Using CFA for soil amendment not only offers a potential solution for the waste disposal problem of CFA, but the phytoextraction of Re by both lucerne and erect milkvetch may also bring an economic profit in the future.

Improved Optimization for Wastewater Treatment and Reuse System Using Computational Intelligence

River water pollution by wastewater can cause significant negative impact on the aquatic sustainability. Hence, accurate modeling of this complicated system and its cost-effective treatment and reuse decision is very important because this optimization process is related to economic expenditure, societal health, and environmental deterioration. In order to optimize this complex system, we may consider three treatment or reuse options such as microscreening filtration, nitrification, and fertilization-oriented irrigation on top of two existing options such as settling and biological oxidation. The objective of this environmental optimization is to minimize the economic expenditure of life cycle costs while satisfying the public health standard in terms of groundwater quality and the environmental standard in terms of river water quality. Particularly, this study improves existing optimization model by pinpointing the critical deficit location of dissolved oxygen sag curve by using analytic differentiation. Also, the proposed formulation considers more practical constraints such as maximal size of irrigation area and minimal amount of filtration treatment process. The results obtained by using an evolutionary algorithm, named a parameter-setting-free harmony search algorithm, show that the proposed model successfully finds optimal solutions while conveniently locating the critical deficit point.

Characterization of the Physicochemical and Biological Properties of Kombolcha Brewery Wastewater Treatment Plant Bio-solid in Relative to Agricultural Uses

Agro-industrial sectors in Ethiopia are highly expanding and offering environmental problems. Some brewery factories in Ethiopia had installed advanced wastewater treatment technologies. Sludge generated from waste treatment plants are recognized as good alternative options for agricultural reuse. However, the difference in sludge properties due to the wastewater action process variation and the inconstant nature of contaminant inputs to the original wastewater, the fertilizer prospective and contaminant risks should be evaluated. Hence, the goal of this study was to illustrate the physical, chemical and biological properties of Kombolcha brewery wastewater treatment plant bio-solid in relative to agricultural reuse. The physicochemical and biological characteristics of the brewery sludge were 7.85, 2.35 mScm-1, 54%, 92.9%, 49.1%, 84.6%, 3.84%, 5.92%, 12.78:1, 5.46 x 106 MPN/ml and 3.06 x 104 MPN/ml for pH, EC, WHC, TS, OC, OM, TKN, P2O5, C/N ratio and TFC (as fresh and dry weight) respectively. The secondary and other plant nutrient contents of the BS were 0.24%, 1.61 mg/Kg for K2O and K, 4.74%, 3.19 mg/ Kg for CaO and Ca, 0.76%, 1.19 mg/Kg for MgO and Mg, 0.86%, 0.37 mg/Kg for Na2O and Na, 2.94% for Al2O3, 27.98% for SiO2 and 0.18% for TiO2 with the detected heavy metals concentration of 0.07, 0.05, 10211.5 and 0.77 mg/Kg for Zn, Pb, Fe and Cu respectively. Overall, the result revealed that the sludge has high OM and P2O5 content that fulfills the suggested standards for the fertilizer value of sludge, optimum pH and EC values, substantial qualities of nitrogen and high WHC and deficient secondary plant nutrients (calcium, magnesium, potassium and sodium), all able to contribute beneficial improvement of soil properties. In line with this, the very lower heavy metals concentration, existed below both the EPA and Canadian class A limits and ideal C/N ratio, meets the fertilizer value of sludge and make it to serve as a valuable organic fertilizer. However, the higher pathogen contents are stabilized to the required standard (<103 MPN/g) for unrestricted reuse of the sludge for agricultural application.

The introduction of resource-saving technology in water treatment plants

The purpose of a technological research is the development of a technology that would allow eliminating the discharge of untreated washing water from a water station in Omsk into the Irtysh, with their repeated use. The paper presents the results of a technological research, which made it possible to determine the optimal technology option for reuse of wash water filters. The studies were carried out by the trial coagulation method, introducing a different amount of contaminated wash water from 10 to 30% into the initial river water and the reagents used in the waterworks. When the combined purification of river and untreated washing water, the turbidity in the settling process decreases to 4.35 mg / l. The efficiency of purification increases with an increase in the amount of raw washing water also increases up to 30%. The technological solutions adopted on the basis of the conducted studies formed the basis for the design documentation for the facilities aimed at developing the re-use of wash water from the Omsk waterworks. The facilities have been built and are being successfully operated now. The proposed solutions made it possible to reduce the intake of water from the source by 10-16.5% and to eliminate the discharge of the contaminated wastewater from the station into the river of Irtysh up to a volume of 51 thousand m3/day.

Archiving the Past While Keeping up with the Times

The e-depot for Dutch archaeology started as a project at Data Archiving and Networked Services (DANS) in 2004 and developed into a successful service, which has ever since been part of the national archaeological data workflow of the Netherlands.While continuously processing archaeological datasets and publications and developing expertise regarding data preservation, various developments are taking place in the data landscape and direct involvement is necessary to ensure that the needs of the designated community are best met. Standard protocols must be defined for the processing of data with the best guarantees for long-term preservation and accessibility. Monitoring the actual use of file formats and the use of their significant characteristics within specific scientific disciplines is needed to keep strategies up-to-date.National developments includes the definition of a national metadata exchange protocol, its accommodation in the DANS EASY self-deposit archive and its role in the central channelling of information submission. In international context, projects such as ARIADNE and PARTHENOS enable further developments regarding data preservation and dissemination. The opportunities provided by such international projects enriched the data by improving options for data reuse, including allowing for the implementation of a map-based search facility on DANS EASY. The projects also provide a platform for sharing of expertise via international collaboration.This paper will detail the positioning of the data archive in the research data cycle and show examples of the data enrichment enabled by collaboration within international projects.

Dry screening – Assessing the effectiveness of contaminant reduction in recovered landfill soils

Landfill mining - an alternative to landfill closure - is designed to recover resources. As landfills consist mainly of soils, the soil quality and possible reuse options are crucial for the economical assessment. The objective of this study is to redistribute contaminants – primarily chemical -- in excavated landfill soils for off-site reuse using exclusively mechanical processing equipment. The waste from two full-scale landfill remediation projects were processed in four different processing plants. The efficiency of contaminant redistribution in soils at each processing plant was investigated using statistical methods.At all four processing plants considerable lower concentrations of heavy metals, polycyclic aromatic hydrocarbons (PAH), total organic carbon (TOC) and sulphate were observed in the coarse-grained soils appropriate for off-site use. In contrast, the differences in leachate analyses (pH, electrical conductivity, chloride, fluoride, barium, dissolved organic carbon) proved to be heterogeneous, less pronounced between fines and coarse-grained soils. Fluoride and chloride sometimes even showed higher concentrations in the coarse-grained. Screens with a mesh size of 50 mm performed more efficiently in terms of contaminant reduction and proportion of material flows (unders and overs) compared to openings of 35 mm or of 70 mm and larger. However, the results indicated an optimum between 35 mm and 50 mm. To ensure the reuse of soils, the determination of contaminants and the grain size distribution should be established in preliminary investigations which are an indispensable requirement for selecting optimal processing equipment and appropriate screen openings.