MUNICIPAL WASTEWATER IN EXPERIMENTS ON RECLAMATION OF LOPARITE ORE DRESSING TAILINGS

Introduction. This paper discusses the effectiveness of using clarified municipal wastewater (CMW) and wastewater sludge (WS) to form stable phytocenoses at the waste storage facilities of the rare metal industry in Murmansk Region. The restoration of the vegetation cover at tailing dumps is limited by the low content of organic matter and associated nitrogen, and the low bioavailability of plant nutrients (K, Ca, Mg, P). The use of WS and other ameliorants of organic nature is a type of chemical amelioration aimed primarily at improving the edaphic properties of man-made soils. Methods. We examined the loparite ore dressing tailings sampled in the operating field of the tailing dump of a rare metal industry enterprise in the center of the Kola Peninsula. In the course of the study, we determined the suitability of the man-made soil for reclamation. To form seeded phytocenosis in a laboratory experiment, seeds of meadow fescue (Festuca pratensis Huds.) were used. The laboratory experiment involved the introduction of CMW, WS, a mixture of WS with silica clay into the soil, and a check. Analysis of the soil and plants was performed using inductively coupled plasma mass spectrometry. The quality of seeded cenosis was assessed according to the following parameters: green biomass, plant height, and projective cover. Results. The preliminary assessment of the man-made soil suitability for reclamation showed the following: the loparite ore dressing tailings have unfavorable characteristics both for the natural regeneration of the vegetation cover and biological reclamation. The introduction of ameliorants had a stimulating effect on the growth of terrestrial biomass during the formation of phytocenosis under laboratory conditions. The results of leaf analysis confirmed the effectiveness of the surface application of organic additives with regard to the loparite ore dressing tailings. Conclusion. In the laboratory experiment with the simulation of surface application, the stimulating effect of unconventional ameliorants (clarified municipal wastewater, wastewater sludge, and its mixture with silica clay) on the supply of nutrients to the reclaimed loparite ore dressing tailings was confirmed. The investigated ameliorants can be recognized as suitable for the biological reclamation of the dressing tailings of the rare metal industry, which does not require costly earthing and the application of protective polymer coatings.

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Modelling of the Chemical Halo of Dust Pollution Migration in Loparite Ore Tailings Storage Facilities

Minerals ◽

10.3390/min11101077 ◽

2021 ◽

Vol 11 (10) ◽

pp. 1077

Author(s):

Eugenia Krasavtseva ◽

Victoria Maksimova ◽

Dmitriy Makarov ◽

Eugeniy Potorochin

Keyword(s):

Maximum Permissible Concentration ◽

Rare Metal ◽

Meteorological Conditions ◽

Storage Site ◽

Dust Pollution ◽

North West ◽

The North ◽

Geotechnical Characteristics ◽

Murmansk Region ◽

Ore Dressing

The article presents a study of the environmental impact of dusting tailing dumps of rare-metal ore dressing in the Murmansk region of Russia. The purpose of the study was to establish patterns in the atmochemical halo migration of the dust pollution of loparite ore dressing tailings. The geotechnical characteristics and material composition of the tailings material have been investigated. Potentially dusty areas identified. Models of dispersion of inorganic dust under different meteorological scenarios are constructed: at low wind load, normal and unfavorable meteorological conditions. The modeling of the spread of pollutants in the area exposed to dust at the storage site was carried out in the program for modeling atmospheric pollution Ecolog-4.60. Calculation of the dispersion of inorganic dust containing 20–70% SiO2 showed that the atmochemical halo of tailings dust pollution spreads over tens of kilometers, and already at a wind speed of about 8 m/s, the concentration of suspended solids at the border of the enterprise sanitary protection zone exceeds the maximum one-time maximum permissible concentration is 3–3.3 times, and under unfavorable meteorological conditions—Dusting reaches the boundaries of the residential area (inhabited locality Revda), located in the north-west of the enterprise, and exceeds the MPCm.o. 1.5 times.

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Physical properties of dewatered wastewater sludge for landfilling

Water Science & Technology ◽

10.2166/wst.1996.0473 ◽

1996 ◽

Vol 34 (3-4) ◽

pp. 533-540 ◽

Cited By ~ 10

Author(s):

A. Koenig ◽

J. N. Kay ◽

I. M. Wan

Keyword(s):

Shear Strength ◽

Hong Kong ◽

Municipal Wastewater ◽

Compressibility Factor ◽

Wastewater Sludge ◽

Municipal Wastewater Treatment ◽

Intrinsic Resistance ◽

Coefficient Of Consolidation ◽

Minimum Requirement ◽

Geotechnical Stability

In the context of landfilling dewatered wastewater sludge in Hong Kong, with landfills up to 140 m high, one of the most significant properties of sludge is its physical nature with regard to moisture characteristics and associated geotechnical stability. Commonly, lower limits are set on total solids content, but no geotechnical stability criteria are applied with the exception of Germany where a minimum requirement for vane shear strength is set at 25 kN/m2. The purpose of this study was to determine and evaluate dewatered wastewater sludge from three Hong Kong municipal wastewater treatment plants with regard to the following physical and geotechnical properties: (i) vane shear strength; (ii) consolidation characteristics such as compression index, compressibility factor, coefficient of consolidation and compressibility coefficient; and (iii) hydraulic characteristics such as permeability and intrinsic resistance. Although dewatered sludge exhibits quite different characteristics as compared to soils, predictive logarithmic relationships may be established between various properties which are consistent with the critical state model for soils, conventional filtration and consolidation theory. Such representation provides a valuable basis for understanding the sludge characteristics and behaviour to landfill design.

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Hydrothermal liquefaction of municipal wastewater sludge and nutrient recovery from the aqueous phase

Biofuels ◽

10.1080/17597269.2020.1863627 ◽

2021 ◽

pp. 1-6

Author(s):

Vinod Kumar ◽

Krishna Kumar Jaiswal ◽

Mikhail S. Vlaskin ◽

Manisha Nanda ◽

M. K. Tripathi ◽

...

Keyword(s):

Aqueous Phase ◽

Municipal Wastewater ◽

Hydrothermal Liquefaction ◽

Wastewater Sludge ◽

Nutrient Recovery

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Anaerobic thermophilic digestion of sewage sludge with a thickened sludge recycle

Water Science & Technology ◽

10.2166/wst.2012.783 ◽

2012 ◽

Vol 65 (3) ◽

pp. 403-409 ◽

Cited By ~ 2

Author(s):

A. Ya. Vanyushina ◽

Yu. A. Nikolaev ◽

A. M. Agarev ◽

M. V. Kevbrina ◽

M. N. Kozlov

Keyword(s):

Retention Time ◽

Municipal Wastewater ◽

Hydraulic Retention Time ◽

Biogas Production ◽

Wastewater Sludge ◽

Recycling Process ◽

Digested Sludge ◽

Volatile Solids ◽

Solids Retention ◽

Thermophilic Digestion

The process of anaerobic thermophilic digestion of municipal wastewater sludge with a recycled part of thickened digested sludge, was studied in semi-continuous laboratory digesters. This modified recycling process resulted in increased solids retention time (SRT) with the same hydraulic retention time (HRT) as compared with traditional digestion without recycling. Increased SRT without increasing of HRT resulted in the enhancement of volatile substance reduction by up to 68% in the reactor with the recycling process compared with 34% in a control conventional reactor. Biogas production was intensified from 0.3 L/g of influent volatile solids (VS) in the control reactor up to 0.35 L/g VS. In addition, the recycling process improved the dewatering properties of digested sludge.

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Wastewater sludge treatment at the municipal wastewater treatment facilities with the purpose of its further utilization

Vodosnabzhenie i sanitarnaia tehnika ◽

10.35776/vst.2021.09.07 ◽

2021 ◽

pp. 46-51

Author(s):

Ю.А. Егорова ◽

В.И. Кичигин ◽

О.И. Нестеренко ◽

А.А. Юдин

Keyword(s):

Wastewater Treatment ◽

Municipal Wastewater ◽

Wastewater Sludge ◽

Mineral Fertilizers ◽

Municipal Wastewater Treatment ◽

Urban District ◽

Sludge Treatment ◽

Technological Waste ◽

Treatment Facilities ◽

Water And Wastewater

Осадки городских очистных канализационных сооружений являются самым массовым технологическим отходом, создающим проблемы утилизации для любого города. Рассмотрены возможные методы обработки осадков сточных вод на городских очистных канализационных сооружениях городского округа Самара с целью их последующей утилизации. Обозначены причины и приведены документальные подтверждениянекорректности возложения ответственности за обращение с такими отходами только на организации водопроводно-канализационного хозяйства. Рассмотрен способ захоронения обезвоженного осадка сточных вод в обвалованном полигоне. Установлено, что обработанные на очистных сооружениях осадки относятся к V классу опасности для окружающей среды. Обработанные, стабилизированные, подсушенные, обезвреженные отходы осадков сточных вод (малоопасный осадок с песколовок при очистке хозяйственно-бытовых и смешанных сточных вод, практически не опасный осадок с песколовок при очистке хозяйственно-бытовых и смешанных сточных вод и избыточный ил биологических очистных сооружений в смеси с сырым осадком) могут быть использованы в качестве наполнителей бетонно-цементных смесей и органоминеральных удобрений или переданы для утилизации сторонним организациям. Sludge from the municipal wastewater treatment facilities is the most massive technological waste that causes trouble for any city. Possible methods of wastewater sludge treatment at the municipal wastewater treatment facilities of the Samara Urban District with the purpose of its further utilization are considered. The reasons are indicated and documentary evidence of the incorrectness of assigning the responsibility for processing such wastes only to the water and wastewater utilities is provided. The method of landfilling dewatered wastewater sludge in a ridged landfill is considered. It has been established that the sludge processed at the wastewater treatment facilities is referred to the V class of environmental hazard. Sludge subjected to the treatment, stabilization, drying and neutralization (low hazardous sludge from grit chambers for domestic and mixed wastewater treatment; almost non-hazardous sludge from grit chambers for domestic and mixed wastewater treatment and excess sludge from biological treatment facilities mixed with raw sludge) can be used as fillers for concrete-cement mixtures and organo-mineral fertilizers or transferred for disposal to outside companies.

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Comparison of Different Electricity-Based Thermal Pretreatment Methods for Enhanced Bioenergy Production from Municipal Sludge

Molecules ◽

10.3390/molecules23082006 ◽

2018 ◽

Vol 23 (8) ◽

pp. 2006 ◽

Cited By ~ 14

Author(s):

E. Hosseini Koupaie ◽

T. Johnson ◽

C. Eskicioglu

Keyword(s):

Energy Production ◽

Municipal Wastewater ◽

Wastewater Sludge ◽

Conventional Heating ◽

P Value ◽

Net Energy ◽

Rf Heating ◽

Thermal Pretreatment ◽

Bioenergy Production ◽

Sequential Pretreatment

This paper presents results for a comprehensive study that compares the performance of three electricity-based thermal pretreatment methods for improving the effectiveness of anaerobic digestion (AD) to process municipal wastewater sludge. The study compares thermal pretreatment using conventional heating (CH), microwave (MW), and radio frequency (RF) heating techniques. The effectiveness of the pretreatment methods was assessed in terms of chemical oxygen demand (COD) and biopolymers solubilization, AD bioenergy production, input electrical energy, and overall net energy production of the sequential pretreatment/AD process. The heating applicators for the bench-scale testing consisted of a custom-built pressure-sealed heating vessel for CH experiments, an off-the-shelf programmable MW oven operating at a frequency of 2.45 GHz for MW heating experiments, and a newly developed 1 kW RF heating system operating at a frequency of 13.56 MHz for RF heating experiments. Under identical thermal profiles, all three thermal pretreatment methods achieved similar sludge disintegration in terms of COD and biopolymer solubilization as well as AD bioenergy production (p-value > 0.05). According to the energy assessment results, the application of CH and MW pretreatments resulted in overall negative energy production, while positive net energy production was obtained through the sequential pretreatment/AD process utilizing RF pretreatment.

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Investigating the effects of different cationic charge flocculation polymers on municipal wastewater sludge dewatering

Water Practice & Technology ◽

10.2166/wpt.2021.046 ◽

2021 ◽

Author(s):

Megan Abrahams ◽

Mujahid Aziz ◽

Godwill Kasongo

Keyword(s):

Municipal Wastewater ◽

Wastewater Treatment Plants ◽

Operating Cost ◽

Wastewater Sludge ◽

Municipal Wastewater Treatment ◽

Bench Scale ◽

Treated Effluent ◽

Solids Concentration ◽

Municipal Wastewater Treatment Plants ◽

Polymer Flocculant

Abstract The minimization of sludge produced by municipal wastewater treatment plants (MWWTPs) is critical as its handling accounts for approximately 50% of the total operating cost. The challenges in predicting dewatering performance can be overcome by optimizing the sludge treatment process, especially conditioning and dewatering. This study aimed to investigate sludge dewaterability at four different MWWTPs, using a gravity drainage test unit and a bench-scale press. The effect of differently treated effluent used as a solvent to mix the flocculation polymers was observed during dewatering. The membrane bioreactor (MBR) treated effluent yielded the highest filtrate volume in the lowest amount of time, with the least polymer flocculant dosage. The Box Behnken Design model fitted the data and proved a relationship between polymer dosage, cake solids concentration, and cake height during the bench-scale press tests.

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