Amount Of Sludge Research Articles

Development of Density Control Technology for Improving Medical Radiation Shielding Performance of Waste Marble Powder Mixture

The marble used at construction sites creates a large amount of sludge after processing. Because waste marble has a high calcium oxide content, it is often used as a concrete mix building material. In this study, the use of waste sludge in the fabrication of radiation shields was investigated for medical shielding applications. A shielding sheet was produced by mixing a polymer and waste marble powder. A method for improving the density of the shielding sheet was developed to improve the shielding performance. To improve the density of the shielding sheet using the WMP mixture, the gap between particles was narrowed by making the WMP particles small and by mixing in a material with a proven shielding effect, such as bismuth oxide. In addition, a stirring defoaming process was used to reduce the voids between particles, and we presented a method to control the density by processing the WMP at a high temperature of 1200 °C. The experimental results revealed that the waste marble powder exhibited the highest shielding effect when mixed with radiation shielding materials such as bismuth oxide. The reduction of voids and the size of the particles used in preparing the shielding sheet proved to be effective in reducing the gap between the particles, resulting in an improvement of shielding of approximately 15% to 20%. The investigated shielding material based on waste marble powder was shown to be effective in shielding low-dose radiation.

Agricultural Use of Urban Sewage Sludge from the Wastewater Station in the Municipality of Alexandria in Romania

Considering the increase in the amount of sewage sludge as a result of the development of urbanization, and the pollution of the environment through the storage of this sludge, the objective of this paper is to analyze the effects of the action of different doses of urban sewage sludge as a fertilizer for agricultural soil. Starting from the legislative recommendations regarding the use of urban sewage sludge in agriculture, we analyzed the sludge resulting from the sewage treatment plant in the Municipality of Alexandria, Romania. This sewage treatment plant, with two technological lines of water and sludge treatment, produces urban sewage sludge without pathogenic bacteria. We highlighted that by applying sewage sludge doses of 15 t/ha and 25 t/ha to agricultural soils, on which we planted soybean and wheat crops. We obtained high yields, and the concentration of heavy metals in the roots, stems and grains of soybean and wheat crops did not exceed the maximum standard limits allowed. Having a high content of organic matter and nutrients important for plants such as nitrogen, ammonium, potassium and zinc, sewage sludge has improved the fertility, physical, chemical and biological properties of the soil, and is able to be used as a fertilizer for degraded soils.

Characteristics of Sludge from the Treatment of Soilless Plant Cultivation Wastewater in a Rotating Electrobiological Disc Contactor (REBDC)

Due to the high nitrogen and phosphorus concentrations in wastewater from soilless cultivation of tomatoes, the sludge formed during wastewater treatment can be used as a source of nutrients in agriculture. The effect of electrical direct current (DC) density (J) and hydraulic retention time (HRT) in a rotating electrobiological contactor (REBDC) on the quantity and quality of sludge generated in the process of tomato soilless cultivation wastewater treatment was determined. The cathode consisted of discs immobilized with biomass, while the anode was an aluminum electrode. HRTs of 4 h, 8 h, 12 h, 24 h and (J) of 0.63, 1.25, 2.50, 5.00, and 10.00 A/m2 were applied. The study showed that the increase in (J) caused an increase in the amount of sludge generated. The increase of (J) contributed to increased concentrations of biogenes in the sludge, whereas extension of HRT at a given current density contributed to increased concentrations of nitrogen and phosphorus (up to 6.2% and 0.8% respectively) and to the reduced content of organic matter (up to 23.04%). The examined sludge was stabilized, sanitary, and safe, and may be an alternative to mineral fertilizers. This study showed that larger sludge amounts are produced in a DC mode aerobic REBDC than in an alternating current anaerobic one.

Life cycle assessment of management/valorisation practices for metal-sludge from treatment of acid mine drainage

The treatment of acid mine drainage in sulphide mining generates large amounts of metal-rich sludge whose management suppose an environmental quandary worldwide. Although traditional practices have focused on safe disposal in landfills, more environmentally friendly solutions may be adopted. The environmental performance of these solutions can be evaluated using tools like Life Cycle Analysis (LCA) that allows the estimation of the cumulative environmental impacts resulting from all stages in the product life cycle. The main goal of this study is, for the first time, to perform a LCA on different management strategies (i.e., i), encapsulation and disposal in landfill; ii) metal recovery using a chemical scheme; iii) pellets manufacturing for phosphorus removal from wastewaters; and iv) brick fabrication) for the metal-rich sludge generated from an active treatment plant. The manufacturing of pelletized material exhibited the lowest impacts (−35 REQs) due mainly to the environmental benefits of wastewater treatment. Despite the undoubtedly economic interest of recovering metals from the sludge, this route exhibited the highest environmental impacts (38 REQs), especially in the categories of fossil depletion (20,943 kg oil eq), marine (64 kg 1,4-dB eq) and freshwater ecotoxicity (50 kg 1,4-dB eq) due to the use of toluene and trybutylphosphate (TBP). The manufacture of bricks could be also an alternative route by obtaining economic value while exhibiting low environmental impacts (0.32 REQs), mainly on marine and freshwater ecotoxicity (0.7 kg 1,4-dB eq). These impacts can be notably reduced if waste materials are used replacing clays or using renewable energies. The encapsulation of these wastes is also a suitable option with a low environmental impact (0.46 REQs), but slightly greater than the brick manufacturing and with no economic return.

Use of Sewage Sludge for the Substitution of Fine Aggregates for Concrete

This work analyzes the use of sewage sludge, generated in wastewater treatment plants, as an alternative for small aggregate to be used in concrete. Concrete cylindrical specimens with height h = 20 cm and diameter D = 10 cm were prepared using different amounts of sludge in the substitution of fine aggregates. Portland cement (CP II Z 32 RS cement) was used in all concrete mixtures, and two water-cement ratios and four cement-sludge mixtures were investigated. Compressive strength, sclerometer index, ultrasonic wave transmission velocity, and water absorption capillary tests were performed. The results showed that the use of sewage sludge as a replacement for fine aggregate to produce concrete exhibited a positive effect on both its compressive strength and its capillary water absorption. The results, even preliminary ones, demonstrated that the sludge could be used as an effective replacement for fine aggregate to produce concrete. The replacement of fine aggregate with 5% sewage sludge proved to be the optimal replacement value for the type of sewage sludge investigated.

Treatment of laundry wastewater by different processes: Optimization and life cycle assessment

Wastewater from industrial laundries is often difficult to treat because it usually presents high turbidity and chemical oxygen demand (COD). We studied several processes for the treatment of laundry wastewater which was provided by a hotel in the south of Gran Canaria, Spain. More specifically, we studied coagulation with iron (III) sulphate, Fenton, photo-Fenton and a biological treatment (using a biofilter, and a granular activated carbon, GAC, filtration). The coagulation and Fenton processes produced large amounts of sludge and could not meet the required standards for water reuse in Spain. The use of photo-Fenton and the BF resulted in complete turbidity removal and high COD removal. However, we found that the effluent from the BF did not meet the COD removal criteria for water reuse, and thus a GAC filtration post-treatment was employed to reduce COD to acceptable levels. The photo-Fenton process alone did meet the criteria for water reuse. The estimated cost to treat 1 m3 of wastewater was 6.72 € for photo-Fenton and 0.71 € for BF + GAC. The cost and life cycle assessment analyses that were also performed revealed that the acquisition of the necessary reagents is the main contribution to the overall economic and environmental costs for both options, and that the BF + GAC option is notably cheaper. Additionally, this option also causes much lower environmental impacts than photo-Fenton.

Fabrication of porous mullite‐based ceramic bricks from Al‐rich water treatment sludge and kaolinitic‐based clay

Fabrication of porous mullite‐based ceramic bricks from Al‐rich water treatment sludge and kaolinitic‐based clay

Spatial analysis of renewable energy sources in Lviv region

The introduction of renewable energy sources makes it possible to expand the possibilities of development of branches of the national economy, in particular heat energy, to accelerate economic growth and reduce the release of greenhouse gases into the environment. Spatial analysis of renewable energy sources contributes to their effective use and allows for planning the local development of renewable energy. In this article, a spatial analysis of renewable energy sources in the Lviv region, such as wind energy, solar radiation, fuel wood, agricultural animal manure, and sewage sludge, is performed. It was established that the most promising district in terms of the availability of renewable energy sources is the Stryi district, since the amount of solar radiation and the amount of forest land in it are higher than the same indicators for other districts, in addition, the amount of sewage sludge is also one of the highest in the region. For the possibility of increasing the total share of renewable energy sources, the districts of the region can cooperate with other districts of both Lviv region and neighboring regions.

Utilization of compost derived from waste sludge of shrimp raising-ponds for crop cultivation

Compost, an organic fertilizer which is rich of nutrients, safe and environmentally friendly for crop cultivation. In this study, it was aimed at evaluatiton of the effects of the compost derived from shrimp pond waste sludge on plant growth of kohlrabi, white radish, and mustard green. The application of the compost produced in five districts (Quynh Luong, Nghi Hop, Dien Trung, Quynh Di, Hung Hoa) of Nghe An province resulted in remarkably higher plant growth. In which kohlrabi, white radish, and mustard green fertilized by the compost from Quynh Luong district had crop yields of 3.6 kg/m2, 3.4 kg/m2, 3.7 kg/m2 than the control without compost yielding 2.1-2.2 kg/m2. Similarly, other plant growth parameters of number and areas of leaves and survival rate of the plants were all significantly higher than that of the control. Moreover, the mustard greens yields applied the compost produced in the four districts including Nghi Hop, Dien Trung, Quynh Di, Hung Hoa were in the range of 3.1-3.6 kg/m2 all higher than that of the control unapplied fertilization determined as 2.2 kg/m2, but reaching relatively equivalent to that of the commercial organic fertilizer at 3.8 kg/m2, but slightly lower than that of the chemical fertilizer 4.4 kg/m2. The study revealed that the compost from shrimp pond waste sludge can be fertilized for crop cultivattion which was safe and contributing to reducing a large amount of waste sludge discharged from shrimp-raising ponds in Nghe An province.

Physio-chemical characterization of sewage sludge generated from sewage treatment plant at Varanasi, in relation to nutrients and heavy metals for agriculture use

Large amount of sewage sludge is generated during waste water treatment at sewage treatment plant (STP), as a result of the sedimentation and suspension of particles. The safe disposal and management of this concentrated sewage sludge posesa major challenge for town and city municipal corporations. However, this could also be used in agriculture as an input to partially replace recommended doses of fertiliser. Thus, the current study was conducted to investigate the physio-chemical and biological characteristics of sewage sludge (SS) and its potential application in agricultural fields as an organic manure. Sewage sludge samples were collected from sewage treatment plant (STP) at Bhagwanpur, Varanasi, India and sieved in 2 mm mesh before being analysed for various physical and chemical characteristics. The processed sewage sludge possessed both major [total nitrogen (1.76 %), total phosphorous (1.29%), total potassium (1.15%)] and micro nutrients (Fe, Mn, Zn and Cu) and significant amount of organic carbon (8.67 %). However, this sewage sludge was also containing considerable amount of heavy metals like Cadmium (7.3 mg kg-1), chromium (49.2 mg kg-1), nickel (total 27.43 mg kg-1), and lead (39.53 mg kg-1), which were reported to be harmful to human beings, but these were lower than threshold limit recommended by Council of the European Communities, 1988 for agricultural use. Further, Bulk density and water holding capacity was 1.18 g cm-3 and 54.5 % respectively. With respect to microfauna, fungi were found more dominating than actinomycetes and bacteria in this sewage sludge. Therefore,considering use of this sewage sludge for agriculture may decrease the use of chemical fertilisers and make it more sustainable. However, in order to increase soil health without posing an environmental risk, sewage sludge must be carefully evaluated before being applied to soil especially for heavy metals and other hazardous pollutants.

Влияние нефтяного шлама на техническое показатели и фазовый состав легковесного кирпича на основе некондиционной глины

On the basis of substandard beidellite clay and oil sludge, a lightweight brick with high technical indicators was obtained. It is advisable to use oil sludge as a thinning agent and a burnout additive. The addition of an optimal amount of oil sludge (30%) to the ceramic mass makes it possible to obtain a lightweight brick of the M100 brand. Underthe optimal content of oil sludge in this work, such an amount is taken, at which the number of plasticity of the ceramic mass (charge) decreases from 18 to 10, since with a smaller number of plasticity of the charge, cracks appearon the products during molding. The study of the phase composition showed that the introduction of oil sludge into the composition of ceramic masses contributes to an increase in anorthite and the formation of diopside. Diopside contributes to the production of high-strength building ceramics in a composition with low-melting clays. Moreover,when diopside is introduced into the raw material, the hardening effect begins in the temperature range of 900-1050°C.

Treatment of Poultry Wastewater with Tannin as a Natural Coagulation Agent

The coagulation-flocculation process frequently employs chemical-based coagulants and flocculants. The disadvantages of utilizing these chemical substances have triggered researchers to investigate natural substances to replace or reduce the number of chemical-based coagulants and flocculants. Thus, this study investigates the potential use of tannin as a natural coagulant for slaughterhouse wastewater treatment. Results indicated that a pH of 6.9 and a dosage of 2mL of tannin resulted in the higher removal of different pollutants from slaughterhouse wastewater. Tannin was able to perform excellent elimination efficiency for all parameters under these ideal conditions. Turbidity, COD, colour, and TSS all had removal efficiencies of 93.7%, 76.2%, 95.7%, and 88.9%, respectively. Results were compared to alum, which was used as a coagulant, and it was found that pH 6.9 and dosage of 5mL were the optimum conditions for alum in slaughterhouse wastewater treatment. Alum achieved 92.8% for turbidity, 75.4% for COD, 93.1% for colour, and 91.7% for TSS, respectively. In contrast to alum, tannin is a natural substance that produces a small quantity of sludge while being safe for the environment and non-toxic. The tannin coagulant has the potential to be an efficient and productive coagulant agent for wastewater treatment from slaughterhouses.

Potential reuse of sludge from a potable water treatment plant in Al Hoceima city in northern Morocco

Producing potable water generates a large amount of sludge, which consumes energy and must be managed and controlled. A case study of a potable water production plant in Al Hoceima City in northern Morocco is described here. The plant produces 15000 ​m3 of potable water each day to meet the water demand of Al Hoceima City, and this causes 3 ​t of sludge to be produced each day. Sludge extracted while producing potable water was characterized, and the possibility of reusing the sludge rather than disposing of it directly to the environment was assessed. The pH, turbidity, aluminum content, and other characteristics of the sludge were determined. Jar tests were performed to determine the optimum coagulant (aluminum sulfate) dose to ensure that the minimum required amount of aluminum sulfate was used. The characterization results indicated that the sludge was stable and reusable. The jar-test results allowed the amount of coagulant used to be optimized and will lead to markedly less sludge being disposed of than is currently the case.

A View of Anaerobic Digestion: Microbiology, Advantages and Optimization

Anaerobic digestion is an efficient technology widely used in biodegradable waste treatment, in which both pollution control and energy recovery could be achieved. Sewage sludge generated by waste water treatment plants is an ideal candidate for anaerobic digestion, for the total amount of sludge could be considerably reduced during the digestion process with a large sum of biogas produced as energy resource for heating, electricity or vehicle power. Although complex microbial community structures and interrelationships in anaerobic digestion process lead to the difficult of managing and maintaining the system, there has been various advanced methods developed to optimize the anaerobic digestion technology. Co-digestion of feedstocks from different sources and pre-treatments with chemical agents, physical methods or biological organics are all proved to be effective methods for enhancement of anaerobic digestion technology in the aspects of pathogen destruction and biogas production.

Study on RDF-5 Production from Oil Sludge and Municipal Solid Wastes

This study mainly used waste oil sludge with different agricultural wastes to conduct experiments. Suitable raw materials were selected to create refuse derived fuel-5 (RDF-5) for a blending and testing analysis to explore the optimal proportions. Different hardeners were added to reduce the processing costs, improve the RDF grain quality, and attain homogeneous fuel. The results revealed that when the oil sludge quantity was too much to be adsorbed by the mushroom grow bag, it could not be granulated. When the proportion of added oil sludge was fixed, adding a higher proportion of polyethylene (PE) increased the particle granulation ratio and completeness. In addition, the particle hardness could be enhanced. If the proportion of added PE was overly high, the material easily aggregated at the melting point (120–130°C), which often caused clogging of the granulation machine dies, thereby overheating and stopping the machine. Results of the calorific value analysis revealed that the calorific values of RDFs of Groups A and B were between 5,214 cal/g and 7,891 cal/g. The calorific values were comparable to that of commonly used solid fuels, indicating that the proposed RDF could be used as an excellent substitute. RDF could be used alone for boilers as the main fuel or used in mixture with other fuels. So far, biomass energy development includes options more than biodiesel and bioalcohol. Considering technological thresholds, market size, and completeness of the upstream and downstream supply chain, this study argued that RDF-5 has many advantages as an energy option and is worthy of biomass energy practitioners’ consideration

Forecasting the municipal sewage sludge amount generated at wastewater treatment plants using some machine learning methods

Forecasting the municipal sewage sludge amount generated at wastewater treatment plants using some machine learning methods

HYDRO-MECHANICAL DRILLING OF WELLS

The solution to the problems of the construction of deep wells is possible when creating downhole tools on a fundamentally new ideological basis, involving physical principles, technical solutions unconventional in the field of drilling equipment. It is important to take into account the energy resources that increase with depth. Following this concept, based on the tasks of geological exploration, a downhole layout has been developed and introduced into the production of drilling wells, with design features and technological capabilities focused on a comprehensive solution to the problems of well wiring. Structurally, the downhole layout aimed at maximizing the potential energy of the working fluid is universal, designed for drilling wells with core sampling of increased diameter (100 mm or more), and with a solid face. In addition to the outer pipe and core receiver, the downhole layout is equipped with diamond drill heads with a stepped matrix, with a separate system of flushing channels, collectively realizing the effect of hydro-mechanical destruction of rocks. By introducing into the composition of the bottom-hole layout, converting the ascending flow into a rotational-ascending one, the problem of removing sludge from under the end of the stepped matrix is effectively solved. Production tests of the downhole layout with core sampling were carried out at the polymetals deposit of Central Kazakhstan, solid face during drilling of groundwater wells in the territory of the Almaty region. According to the results of production tests, it was found that the hydro-mechanical destruction of rocks is especially effective in combination with diamond drill heads with a stepped matrix. The presence of a turbulator-expander in the bottom-hole layout made it possible to significantly increase the amount of incoming sludge of drilled rock in the well sump, especially when drilling wells with a solid face. In comparable geological and technical conditions of drilling wells, serial core sets HQ with a drilling diameter of 95.6 mm had the following indicators: energy consumption – 2.1-2.4 kW / hour, core yield with a diameter of 63 mm – 93%, specific lumpiness of the core – 5-8 pcs / per linear meter of drilling, drilling was carried out at an axial load of 2200-2500 kgf, rotation speed 500-700 rpm. Similar indicators of the downhole layout: energy consumption – 1.2-1.5 kW / hour, core yield – 98-100% with a diameter of 112 mm, specific lumpiness – 2-3 pieces, axial load – 700-900 kgf, rotation speed – 300-400 rpm.

Municipal Wastewater and Sludge Treatment Detection Technology in Water Environment Protection

In the process of municipal development in China, we should give top priority to the conservation of water resources. Currently, environmental pollution is the most important environmental problem in the development of municipalization in China. The construction scale of municipal wastewater treatment plant has been further expanded, and the relevant municipal wastewater treatment process has been improved. In the process of municipal wastewater treatment, a large amount of sludge will be produced. Under the action of rainwater seepage, a large amount of wastewater from wastewater will flow into the river around the city, resulting in secondary pollution. Therefore, the municipal treatment plant for wastewater should pay attention to sludge treatment during wastewater treatment, the introduction of new wastewater treatment technology, improve the wastewater treatment process, to avoid more sludge in the wastewater treatment process, so as not to give rise to secondary pollution to the rivers around the city.

Relevance of Pyrolysis Products Derived from Sewage Sludge for Soil Applications

The recovery of sludge produced in the wastewater treatment process in WWTPs is often limited by the high content of toxic forms of contaminants of both an inorganic and organic nature. One of the options for the effective treatment of the world’s ever-increasing quantities of sewage sludge is the pyrolysis process. Thermochemical conversion of sewage sludge is emerging as a promising method for treating these heterogeneous and highly complex wastes with increasing research work. Pyrolysis-treated sewage sludge (PM) prepared at 603–615 °C was characterized by pH, EC, and CHN-S analysis; total and bioavailable concentrations of P and heavy metals (Cd, Cu, Fe and Zn); fractionation of bound forms of P and heavy metals in the material and determination of the presence of polycyclic aromatic hydrocarbons (PAHs). The studied material was subjected to ecotoxicological tests (Daphnia pulex L.) and cultivation tests (Lactuca sativa L.). Elemental analysis revealed the concentrations of heavy metals in PM: Fe (137,600 mg/kg), Zn (2602 mg/kg), Cu (582 mg/kg), Cr (107 mg/kg), Pb (87 mg/kg), Ni (67 mg/kg), As (<1 mg/kg), Hg (<2 mg/kg) and Cd (<1 mg/kg). The highest values of extractability of the investigated heavy metals from PM were found in the cases of Zn (HCl) and Fe (Mehlich 3), both values not exceeding 500 mg/kg. BCR sequential extraction showed the major concentrations of Cu and Fe were predominantly bound in the residual fraction (F4) and Zn in the reducible fraction (F2) of PM. The results of heavy metal bioavailability suggest that the addition of PM does not negatively affect the growth of lettuce biomass and the metal contents of plant tissues. Based on the results obtained, the pyrolysis material prepared from municipal sewage sludge seems to be a promising and innovative soil additive and a potential alternative to conventional inorganic fertilizers.

Mechanical Strength, Permeability, and Micromechanics of Municipal Sludge Modified with Calcium-Containing Industrial Solid Waste and Powdered Construction Waste

Each year, China produces a substantial amount of municipal sludge, industrial waste (slag, fly ash, and desulfurized gypsum), and construction waste, while its recycling rate is low. If not disposed in a properly and timely manner, this inequity can have serious environmental impacts. This study aimed to prepare a new type of modified sludge material with high strength, low shrinkage, and low permeability by curing municipal sludge with industrial waste (slag, desulfurized gypsum, and fly ash) and powdered construction waste. At specific maintenance ages, the modified sludge material was examined for shrinkage deformation, water content, compressive strength, and hydraulic conductivity. The modified sludge material was also tested by scanning electron microscopy (SEM + EDS), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR) tests. The hydration products, micromorphology, and elemental composition of modified sludge were also analyzed at specific maintenance ages. These analyses revealed the mechanism of solidification of municipal sludge by industrial waste and powdered construction waste and the changes in the microstructure of the sludge. The results showed that the compressive strength of the modified sludge ranged from 3.83 to 8.63 MPa, volumetric shrinkage ranged from 2.12 to 12.68%, and hydraulic conductivity ranged from 1.65 × 10−8 to 2.21 × 10−7 cm/s after 28 d of maintenance. The active substances, such as SiO2, Al2O3, and CaO, in the industrial waste, powdered construction waste, and municipal sludge were subjected to a hydration reaction in an alkaline environment to produce dense blocks, agglomerates of C-S-H, ettringite, gismondine, and other hydration products. The compressive strength of the modified sludge increased, and its internal structure was dense.