The role of sludge conditioning and dewatering in the fate of nonylphenol in sludge-amended soils

2008 ◽  
Vol 57 (3) ◽  
pp. 329-335 ◽  
Author(s):  
V. N. Kouloumbos ◽  
A. Schäffer ◽  
P. F.-X. Corvini

One of the main concerns associated with the recycling of biosolids to arable land is their contamination by organic pollutants, like endocrine disruptors. Conditioning and dewatering are usually the last steps of the sewage sludge treatment, before its further utilization. The choice of the specific conditioning/dewatering method may have an effect, not only on the amount of residues in the biosolids, but also on the fate of these compounds in amended soils. Anaerobically digested wastewater sludge was conditioned at lab-scale by means of physical and chemical methods and subsequently dewatered by centrifugation. The produced biosolids plus non-conditioned and non-dewatered sludges were amended separately to soil and spiked with 14C radiolabelled single isomer of nonylphenol. The persistence and leaching potential of nonylphenol after an incubation period of three months were correlated to the sludge treatment method. In comparison to non-conditioned sludge, 54% and 72% higher amount of pollutant residues were extractable when freeze-thawed and limed sludge, respectively, were used. Conditioning of sludge with cationic polymer decreased the leaching potential of nonylphenol in sludge-amended soils, while liming increased it. Fractions of the model compound recovered as extractable and bound residues were analyzed in order to interpret nonylphenol fate.

Author(s):  
N. E. Gutorova ◽  
◽  
O. V. Dymnikova ◽  

Introduction. The article deals with the problems of treatment of organic sludge from the purification of municipal wastewater in Rostov-on-Don. To solve this problem, a method of anaerobic (methane) digestion of sewage sludge was proposed. Problem Statement. The objective of this study is to determine the role of anaerobic stabilization for Rostovvodokanal company. Theoretical Part. The differences between mesophilic and thermophilic modes of sediment digestion were determined, a technological line for preparing biogas for use was proposed. Calculations of the main parameters of the anaerobic digestion process in the digester have been made. Conclusion. The results of the analysis showed that with the help of this modernization, the main problems are solved.


2021 ◽  
Author(s):  
Samaneh Tahervand ◽  
Mohsen Jalali ◽  
Wolfram Buss

Abstract Biochar production via pyrolysis is a promising option to be used for sewage sludge treatment. Here we investigated the uptake of potentially toxic elements (PTEs) from sewage sludge and its biochar (450°C) into cherry tomato plants and its fruits in pot experiments (2, 5 and 10%) to assess the health risks associated with fruit consumption. We further studied the ability of the PTE-rich amendments to immobilize PTEs already present in soil through spiking of soil (pH 7.4) with Cd, Cu and Zn. Our findings suggest that tomato consumption is not a human health risk when grown in soil amended with sewage sludge and its biochar; in most treatments PTE uptake into fruits was similar to the control. Vegetative plant growth was highest in sewage sludge-amended soils. Yet 5 and 10% biochar-amended soils significantly increased tomato fruit yield compared to untreated sewage sludge application (400–500% higher than 10% sewage sludge-amended soil) and significantly decreased fruit uptake of Cu and Zn. Importantly, biochar also significantly immobilized PTEs present in contaminated (spiked) soil. As expected, available (DTPA-extractable) PTE contents were typically lower in biochar-amended soil and sequential extraction indicated that the PTEs were predominantly bound in more recalcitrant soil fractions (organic matter associated and Fe-Mn oxides-bound). We conclude that pyrolysis can be a key technology for sewage sludge treatment and subsequent use of the biochar in urban, and potentially even contaminated, horticultural sites.


2017 ◽  
pp. 188-196
Author(s):  
Hanna Värri ◽  
Jouni Havukainen ◽  
Mika Horttanainen Horttanainen

Insufficient wastewater treatment causes serious problems for the environment and health in the Leningrad Region. Even though wastewater treatment has been improving during the last decade, almost no attention has been paid to the wastewater sludge treatment. Nutrient emissions from the organic wastes, including wastewater sludge, are among the most significant sources of the eutrophication of the Baltic Sea. Disposal of sludge causes also significant greenhouse gas emissions, polluting local water resources and filling up the landfill sites. Currently the main treatment method of wastewater sludge in Russia is so called aging. This means that sludge is stored in piles from some months up to some years, and after that the sludge is disposed to landfills. In order to develop wastewater sludge treatment, it is essential to know the properties of the material treated. In Russia, wastewater sludge is often expected to contain high amounts of heavy metals. This is a significant challenge for material or energy recovery from the sludge. Different possible treatment methods of wastewater sludge are discussed in this paper. The properties and composition of wastewater sludge from two different municipal wastewater treatment plants are defined and discussed in the paper. The main properties are volatile and total solids, moisture and ash content, inorganic compounds, heavy metal contents, and the lower heating value of dry matter. The effect of the properties on energy and nutrient recovery purposes are evaluated.


2019 ◽  
Vol 1 (7) ◽  
pp. 65-71
Author(s):  
O. A. Egorova ◽  
K. A. Novikov

Presented current data on the etiology of rosacea, the main aspects of pathogenesis, clinical forms of the disease. Reflects trigger factors leading to rosacea, as well as complicating its course. Modern methods of treatment are described, including the use of new safe preparations of ivermectin and brimonidine, providing a good, lasting effect of clinical manifestations of rosacea. The role of laser technology, actively occupying a leading place in the choice of physiotherapeutic treatment method, is noted. The need for an individual approach in the choice of therapy for each patient with rosacea is emphasized.


2007 ◽  
Vol 2 (1) ◽  
Author(s):  
Petia Mijaylova Nacheva ◽  
G. Moeller-Chávez ◽  
E. Ramírez-Camperos ◽  
L. Cardoso-Vigueros

The tropical regions have specific problems associated with high pathogenic density in the sewage sludge. The aim of this study was to select an adequate sludge stabilization and valorization system comparing the performance of four technologies: anaerobic stabilization without heating, aerobic stabilization, alkaline treatment with lime and aerobic composting. The study was performed in a pilot plant which was built and operated during six months. The main problem for the beneficial use of the sludge was its pathogenicity. All the systems allowed obtaining stabilized products which met the bacteriological criteria for some kind of use. The compost and the alkalinized sludge were bacteriologically safe for use without restrictions in accordance with the Mexican regulations. The accomplishment of the parasitological criteria for use was however impossible with the anaerobic and with the aerobic systems. The compost obtained at 55-60°C with 25d aeration time and the alkaline sludge fulfill the criteria established by for forest and agriculture use and for soil conditioning. The composting could reach the requirements for unrestricted use when operated at temperatures 65-70°C during 45 days which makes it the most adequate sludge treatment system for hot climate regions.


2007 ◽  
Vol 2 (1) ◽  
Author(s):  
A. Meda ◽  
C. Schaum ◽  
M. Wagner ◽  
P. Cornel ◽  
A. Durth

TIn 2004, the German Association for Wastewater, Water and Waste (DWA) carried out a survey about the current status of sewage sludge treatment and disposal in Germany. The study covered about one third of the wastewater treatment plants and about two thirds of the entire treatment capacity (expressed in population equivalents) in Germany. This provides an up-to-date and representative database. The paper presents the most important results regarding sludge treatment, process engineering, current disposal paths and sewage sludge quality.


1989 ◽  
Vol 21 (8-9) ◽  
pp. 909-916
Author(s):  
A. M. Spaull ◽  
D. M. McCormack ◽  
E. B. Pike

Samples of sewage sludges, taken over a 12-month period from 9 Scottish sewage works, contained on average 0.24 cysts of Globodera spp. (potato cyst-nematodes) of which 11% were viable. The incidence was not significantly related to season or to the presence of vegetable-processing effluent. Exposure of cysts in sludge to mesophilic anaerobic digestion (35 °C, 30 min) cold anaerobic digestion (9 weeks), pasteurisation (70 °C, 30 min) and aerobic thermophilic digestion (60 °C, ld) reduced viability of eggs within the cysts by almost 100%. Sludges so treated can therefore be considered to be free from infection risk to potato crops, although the non-infective cysts may still be recovered. Treatment with lime at pH 11.5 (20 °C, 24 h), by aerobic stabilisation in an oxidation ditch (7 weeks) and by activated-sludge treatment (5d) did not reduced viability acceptably. Accelerated cold digestion did not reduce viability sufficiently after the usual 15 weeks but rendered eggs completely non-viable after 21 weeks. The results show that even sludge treated to destroy viable cysts should not be applied to land used for growing seed potatoes and subject to testing for freedom from infestation. Treatment destroying viability should increase the acceptability of sludge for ware potato growers, although the numbers of cysts applied in untreated sludge would be unlikely to increase significantly levels of cysts in soils already infested.


Energies ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2697
Author(s):  
Gabriel Gerner ◽  
Luca Meyer ◽  
Rahel Wanner ◽  
Thomas Keller ◽  
Rolf Krebs

Phosphorus recovery from waste biomass is becoming increasingly important, given that phosphorus is an exhaustible non-renewable resource. For the recovery of plant nutrients and production of climate-neutral fuel from wet waste streams, hydrothermal carbonization (HTC) has been suggested as a promising technology. In this study, digested sewage sludge (DSS) was used as waste material for phosphorus and nitrogen recovery. HTC was conducted at 200 °C for 4 h, followed by phosphorus stripping (PS) or leaching (PL) at room temperature. The results showed that for PS and PL around 84% and 71% of phosphorus, as well as 53% and 54% of nitrogen, respectively, could be recovered in the liquid phase (process water and/or extract). Heavy metals were mainly transferred to the hydrochar and only <1 ppm of Cd and 21–43 ppm of Zn were found to be in the liquid phase of the acid treatments. According to the economic feasibility calculation, the HTC-treatment per dry ton DSS with an industrial-scale plant would cost around 608 USD. Between 349–406 kg of sulfuric acid are required per dry ton DSS to achieve a high yield in phosphorus recovery, which causes additional costs of 96–118 USD. Compared to current sewage sludge treatment costs in Switzerland, which range between 669 USD and 1173 USD, HTC can be an economically feasible process for DSS treatment and nutrient recovery.


Energies ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 276
Author(s):  
Francesco Facchini ◽  
Giovanni Mummolo ◽  
Micaela Vitti

The sewage sludges are the byproducts of the wastewater treatment. The new perspective of the wastewater value chain points to a sustainable circular economy approach, where the residual solid material produced by sewage sludge treatments is a resource rather than a waste. A sewage sludge treatment system consists of five main phases; each of them can be performed by different alternative processes. Each process is characterized by its capability to recover energy and/or matter. In this paper, a state of the art of the sludge-to-energy and sludge-to-matter treatments is provided. Then, a scenario analysis is developed to identify suitable sewage sludge treatments plants that best fit the quality and flowrate of sewage sludge to be processed while meeting technological and economic constraints. Based on the scientific literature findings and experts’ opinions, the authors identify a set of reference initial scenarios and the corresponding best treatments’ selection for configuring sewage sludge treatment plants. The scenario analysis reveals a useful reference technical framework when circular economy goals are pursued. The results achieved in all scenarios ensure the potential recovery of matter and/or energy from sewage sludges processes.


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