scholarly journals Occurrence and Fate of Heavy Metals in Municipal Wastewater in Heilongjiang Province, China: A Monthly Reconnaissance from 2015 to 2017

Water ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 728 ◽  
Author(s):  
Peng Du ◽  
Lingrong Zhang ◽  
Yuntao Ma ◽  
Xinyue Li ◽  
Zhenglu Wang ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Urban Areas ◽  
Municipal Wastewater ◽  
Flow Analysis ◽  
Material Flow Analysis ◽  
Wastewater Sludge ◽  
County Level ◽  
Heilongjiang Province ◽  
Municipal Wastewater Treatment ◽  
Modeling Tools

As one of the major sources of pollutions in the environments, effluents from municipal wastewater recently became a hot topic. This study quantified monthly county-level releases of five heavy metals, i.e., lead (Pb), cadmium (Cd), chromium (Cr), arsenic (As), and mercury (Hg), from municipal wastewater into the environment in the Heilongjiang Province of China, based on sampling, measurement, and modeling tools. Wastewater samples were collected from 27 municipal wastewater treatment plants (MWTPs) in 15 county-level cities of Heilongjiang every month from 2015 to 2017. The concentrations of five heavy metals were analyzed in both influents (Pb: 160 ± 100 μg/L; Cd: 15 ± 9.0 μg/L; Cr: 170 ± 64 μg/L; Hg: 0.67 ± 1.5 μg/L; As: 6.2 ± 4.8 μg/L) and effluents (Pb: 45 ± 15 μg/L; Cd: 5.2 ± 5.1 μg/L; Cr: 57 ± 13 μg/L; Hg: 0.28 ± 0.12 μg/L; As: 2.6 ± 1.4 μg/L). The removal ratios of the five heavy metals ranged from 50% to 67%. Inflow fluxes of Pb, Cr, and Cd displayed increasing trends first then decreased after reaching a maximum value, whereas those of Hg and Pb remained stable. Material flow analysis reveals that constructions of MWTPs are conducive to significantly reduce the releases of heavy metals from urban areas into the aquatic environment in the study area. Additionally, municipal wastewater sludge (used as fertilizer or spread on the land) could be a significant source of heavy metals in the land.

Physical properties of dewatered wastewater sludge for landfilling

1996 ◽  
Vol 34 (3-4) ◽  
pp. 533-540 ◽  
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.

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

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.

scholarly journals STUDY ON SLUDGE TREATMENT BY THE AEROBIC STABILIZATION PROCESS COMBINES WITH BULKING AGENT AND HEATED AIR SUPPLY

2020 ◽  
Vol 58 (5A) ◽  
pp. 190
Author(s):  
Khoi Diep Ngoc Vo
Keyword(s):  
Urban Areas ◽  
Municipal Wastewater ◽  
Organic Fertilizer ◽  
Treatment Plant ◽  
Bulking Agent ◽  
Municipal Wastewater Treatment ◽  
Treatment Technology ◽  
Sludge Treatment ◽  
Stabilization Process ◽  
Heated Air

The paper presents the results of the evaluation of sludge decomposition ability from a municipal wastewater treatment plant by an aerobic process on the Mishimax device (MK-50). The principle of the process was based on the microorganisms activated by the bulking agent as a bio-carrier to decompose organics composition and increase the evaporation by heating. An average sludge amount of 30 kg/day was added into MK-50, with the moisture of 80.2 – 83.6 %, with the C/N ratio of around 22 - 35. The heated air with 50 oC in temperature was supplied into a rotary bioreactor during the experiment period. After every 30 days of fermentation, the results from three experiments showed that the sludge volume decreased from 83 - 85 %, the stabilization efficiency by dry weight of sludge reached at 32 - 39 %, corresponding to the average decomposition rate is 12 g/kg.day, the evaporation efficiency was more than 95 %. Sludge after stabilization process had the colour of brown-grey, pH of about 6.5 - 7.2, the humus particles with the size of less than 1 mm accounted for over 60 %, the evaluation of product indexes according to nutrients like TOC, T-N meet the standard of 10TCN 526:2002/BNN&PTNT. The stabilized sludge was used for growth plant test and compared to a market organic fertilizer under the same conditions of cultivation and monitoring. The initial results of this study were a basis for research of sludge treatment technology approaches to waste recycling orientation in urban areas in Vietnam.

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

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.

Improved alkaline stabilization of municipal wastewater sludge

2002 ◽  
Vol 46 (10) ◽  
pp. 139-146 ◽  
Author(s):  
J.M. Mendez ◽  
B.E. Jiménez ◽  
J.A. Barrios
Keyword(s):  
Municipal Wastewater ◽  
Treatment Plant ◽  
Physicochemical Process ◽  
Wastewater Sludge ◽  
The Other ◽  
Stabilization System ◽  
Municipal Wastewater Treatment ◽  
Faecal Coliforms ◽  
Salmonella Spp ◽  
Closed Systems

In Mexico, physicochemical sludge contains high levels of pathogens; and alkaline stabilization is an alternative for their control. However, the odours caused mainly by ammonia generation represent a disadvantage. On the other hand, the ammonia is known as an effective disinfectant. The aim of this study was to evaluate the disinfectant properties of ammonia in sludge, and use it in a closed alkaline stabilization system, which, not only copes with odours but also increases the efficiency of the process. Raw sludge from a municipal wastewater treatment plant using a physicochemical process was used. Ammonia was applied in doses from 10 to 50% w/w; also, doses from 5 to 40% of CaO were applied in open and closed systems and raw and treated sludge quality was evaluated. Results showed that ammonia removed 6 and 5 logs of faecal coliforms and Salmonella spp., respectively and up to 94% of viable helminth ova. The closed system was more efficient than the open system when applying doses from 5 to 20% of CaO. Finally, the results indicate that the ammonia represents an alternative to disinfecting wastewater sludge and it can be used to enhance alkaline stabilization processes.

scholarly journals The Design of Sustainable City Multi-Floor Manufacturing Processes Under Uncertainty in Supply Chains

2020 ◽  
Vol 12 (22) ◽  
pp. 9439
Author(s):  
Tygran Dzhuguryan ◽  
Agnieszka Deja ◽  
Bogusz Wiśnicki ◽  
Zofia Jóźwiak
Keyword(s):  
Supply Chains ◽  
Urban Areas ◽  
Flow Analysis ◽  
Material Flow Analysis ◽  
Performance Model ◽  
Sustainable City ◽  
Sustainable Supply Chains ◽  
Capacity Loss ◽  
Proposed Model ◽  
The City

The application of multi-floor manufacturing (MFM) in huge cities is related to the rational use of urban areas and the solution to traffic problems. The operation of the city MFM clusters depends on the efficiency of production and transport management considering technical, economic, environmental, and other factors. The primary goal of this paper was to identify and analyze the drivers of sustainable supply chains (SSCs) that influence or encourage the design of sustainable processes in city MFM clusters under uncertainty in supply chains. This paper presents an SSC performance model for city MFM clusters under uncertainty. The proposed model is universal and is based on material flow analysis (MFA) methodology. The presented analysis helps to determine the conditions for rhythmic deliveries with the use of the multi-IRTs. The coefficients of rhythmic deliveries for multiple intelligent reconfigurable trolleys (IRTs) and the capacity loss of freight elevators allow us to periodically assess the sustainability processes in city MFM clusters related to the flow materials. These assessments are the basis for the decision-making and planning of SSCs.

scholarly journals The bottlenecks and causes, and potential solutions for municipal sewage treatment in China

2020 ◽  
Vol 15 (1) ◽  
pp. 160-169 ◽  
Author(s):  
Yeshi Cao ◽  
M. C. M. Van Loosdrecht ◽  
Glen. T. Daigger
Keyword(s):  
Wastewater Treatment ◽  
Nutrient Removal ◽  
Urban Areas ◽  
Municipal Wastewater ◽  
Wastewater Treatment Plants ◽  
Sewage Treatment ◽  
Integrated Design ◽  
Cost Effective ◽  
Municipal Sewage ◽  
Municipal Wastewater Treatment

Abstract Since about the 1990s China has achieved remarkable progress in urban sanitation. The country has built very extensive infrastructure for wastewater treatment, with 94.5% treatment coverage in urban areas and legally mandated nation-wide full nutrient removal implemented. However, municipal wastewater treatment plants (WWTPs) in China are still confronted with issues rooted in the unique sewage characteristics. This study compares energy recovery, cost of nutrient removal and sludge production between Chinese municipal WWTPs and those in countries with longer wastewater treatment traditions, and highlights the cause-effect relationships between Chinese sewage characteristics – high inorganic suspended solids (ISS) loads, and low COD and C/N ratio, and municipal WWTP process performance in China. Integrated design and operation guidelines for municipal WWTPs are imperative in relation to the unique sewage characteristics in China. Cost-effective measures and solutions are proposed in the paper, and the potential benefits of improving the sustainability of municipal WWTPs in China are estimated.

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