Disinfection Performance in Wastewater Stabilization Ponds in Cold Climate Conditions: A Case Study in Nunavut, Canada

Throughout history, gardens and garden designing has been in the attention of Persian architects who had special expertise in the construction of gardens. The appearance of Islam and allegories of paradise taken from that in Koran and Saints’ sayings gave spirituality to garden construction. Climate conditions have also had an important role in this respect but little research has been done about it and most of the investigations have referred to spiritual aspects and forms of garden. The cold and dry climate that has enveloped parts of West and North West of Iran has many gardens with different forms and functions, which have not been paid much attention to by studies done so far. The aim of this paper is to identify the features and specifications of cold and dry climate gardens with an emphasis on Tabriz’s Gardens. Due to its natural and strategic situation, Tabriz has always been in the attention of governments throughout history; travellers and tourists have mentioned Tabriz as a city that has beautiful gardens. But, the earthquakes and wars have left no remains of those beautiful gardens. This investigation, by a comparative study of the climates in Iran and the effect of those climates on the formation of gardens and garden design, tries to identify the features and characteristics of gardens in cold and dry climate. The method of study is interpretive-historical on the basis of written documents and historic features and field study of existing gardens in this climate. The results show that, with respect to natural substrate, vegetation, the form of water supply, and the general form of the garden; gardens in dry and cold climate are different from gardens in other climates.

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Candidate areas for wastewater stabilization ponds utilizing GIS and metal adsorption capacities of native clayey deposits: Mornag case study (NE Tunisia)

Bulletin of Engineering Geology and the Environment ◽

10.1007/s10064-018-1376-5 ◽

2018 ◽

Vol 78 (6) ◽

pp. 4567-4578

Author(s):

Jamel Ayari ◽

Rim Azouzi ◽

Abdelkrim Charef ◽

Amor Smati

Keyword(s):

Metal Adsorption ◽

Adsorption Capacities ◽

Stabilization Ponds ◽

Wastewater Stabilization Ponds

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Pathogen removal mechanisms in anoxic wastewater stabilization ponds

Water Science & Technology ◽

10.1016/0273-1223(96)00348-4 ◽

1996 ◽

Vol 33 (7) ◽

Cited By ~ 7

Keyword(s):

Pathogen Removal ◽

Stabilization Ponds ◽

Removal Mechanisms ◽

Wastewater Stabilization Ponds

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A Weighted-Time-Lag Method to Detect Lag Vegetation Response to Climate Variation: A Case Study in Loess Plateau, China, 1982–2013

Remote Sensing ◽

10.3390/rs13050923 ◽

2021 ◽

Vol 13 (5) ◽

pp. 923

Author(s):

Qianqian Sun ◽

Chao Liu ◽

Tianyang Chen ◽

Anbing Zhang

Keyword(s):

Climate Change ◽

Loess Plateau ◽

Time Lag ◽

New Method ◽

Climate Factors ◽

The Loess Plateau ◽

Climate Conditions ◽

Vegetation Growth ◽

Lag Effect

Vegetation fluctuation is sensitive to climate change, and this response exhibits a time lag. Traditionally, scholars estimated this lag effect by considering the immediate prior lag (e.g., where vegetation in the current month is impacted by the climate in a certain prior month) or the lag accumulation (e.g., where vegetation in the current month is impacted by the last several months). The essence of these two methods is that vegetation growth is impacted by climate conditions in the prior period or several consecutive previous periods, which fails to consider the different impacts coming from each of those prior periods. Therefore, this study proposed a new approach, the weighted time-lag method, in detecting the lag effect of climate conditions coming from different prior periods. Essentially, the new method is a generalized extension of the lag-accumulation method. However, the new method detects how many prior periods need to be considered and, most importantly, the differentiated climate impact on vegetation growth in each of the determined prior periods. We tested the performance of the new method in the Loess Plateau by comparing various lag detection methods by using the linear model between the climate factors and the normalized difference vegetation index (NDVI). The case study confirmed four main findings: (1) the response of vegetation growth exhibits time lag to both precipitation and temperature; (2) there are apparent differences in the time lag effect detected by various methods, but the weighted time-lag method produced the highest determination coefficient (R2) in the linear model and provided the most specific lag pattern over the determined prior periods; (3) the vegetation growth is most sensitive to climate factors in the current month and the last month in the Loess Plateau but reflects a varied of responses to other prior months; and (4) the impact of temperature on vegetation growth is higher than that of precipitation. The new method provides a much more precise detection of the lag effect of climate change on vegetation growth and makes a smart decision about soil conservation and ecological restoration after severe climate events, such as long-lasting drought or flooding.

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Microbial contamination in groundwater supply in a cold climate and coarse soil: case study of norovirus outbreak at Lake Mývatn, Iceland

Hydrology Research ◽

10.2166/nh.2013.076 ◽

2013 ◽

Vol 44 (6) ◽

pp. 1114-1128 ◽

Cited By ~ 13

Author(s):

M. J. Gunnarsdottir ◽

S. M. Gardarsson ◽

H. O. Andradottir

Keyword(s):

Rural Areas ◽

Microbial Contamination ◽

Removal Rate ◽

Late Summer ◽

Cold Climate ◽

Systematic Evaluation ◽

Septic Systems ◽

Groundwater Velocity ◽

Groundwater Supply

This paper explores the fate and transport of microbial contamination in a cold climate and coarse aquifers. A confirmed norovirus outbreak in a small rural water supply in the late summer of 2004, which is estimated to have infected over 100 people, is used as a case study. A septic system, 80 m upstream of the water intake, is considered to have contaminated drinking water. Water samples tested were negative for coliform and strongly positive for norovirus. Modelling predicts that a 4.8-log10 removal was possible in the 8 m thick vadose zone, while only a 0.7-log10 and 2.7-log10 removal in the aquifer for viruses and Escherichia coli, respectively. The model results support that the 80 m setback distance was inadequate and roughly 900 m aquifer transport distance was needed to achieve 9-log10 viral removal. Sensitivity analysis showed that the most influential parameters on model transport removal rate are grain size diameter and groundwater velocity, temperature and acidity. The results demonstrate a need for systematic evaluation of septic systems in rural areas in lesser studied coarse strata at low temperatures, thereby strengthening data used for regulatory requirements for more confident determination on safe setback distances.

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Model Based Biomass System Design of Feedstock Supply Systems for Bioenergy Production

Volume 2B: 33rd Computers and Information in Engineering Conference ◽

10.1115/detc2013-13559 ◽

2013 ◽

Cited By ~ 9

Author(s):

Kara G. Cafferty ◽

David J. Muth ◽

Jacob J. Jacobson ◽

Kenneth M. Bryden

Keyword(s):

Supply Chain ◽

Corn Stover ◽

Cellulosic Ethanol ◽

Supply System ◽

Cellulosic Biomass ◽

Systems Dynamics ◽

Climate Conditions ◽

Unit Operations ◽

Supply Systems

Engineering feedstock supply systems that deliver affordable, high-quality biomass remains a challenge for the emerging bioenergy industry. Cellulosic biomass is geographically distributed and has diverse physical and chemical properties. Because of this feedstock supply systems that deliver cellulosic biomass resources to biorefineries require integration of a broad set of engineered unit operations. These unit operations include harvest and collection, storage, preprocessing, and transportation processes. Design decisions for each feedstock supply system unit operation impact the engineering design and performance of the other system elements. These interdependencies are further complicated by spatial and temporal variances such as climate conditions and biomass characteristics. This paper develops an integrated model that couples a SQL-based data management engine and systems dynamics models to design and evaluate biomass feedstock supply systems. The integrated model, called the Biomass Logistics Model (BLM), includes a suite of databases that provide 1) engineering performance data for hundreds of equipment systems, 2) spatially explicit labor cost datasets, and 3) local tax and regulation data. The BLM analytic engine is built in the systems dynamics software package Powersim™. The BLM is designed to work with thermochemical and biochemical based biofuel conversion platforms and accommodates a range of cellulosic biomass types (i.e., herbaceous residues, short-rotation woody and herbaceous energy crops, woody residues, algae, etc.). The BLM simulates the flow of biomass through the entire supply chain, tracking changes in feedstock characteristics (i.e., moisture content, dry matter, ash content, and dry bulk density) as influenced by the various operations in the supply chain. By accounting for all of the equipment that comes into contact with biomass from the point of harvest to the throat of the conversion facility and the change in characteristics, the BLM evaluates economic performance of the engineered system, as well as determining energy consumption and green house gas performance of the design. This paper presents a BLM case study delivering corn stover to produce cellulosic ethanol. The case study utilizes the BLM to model the performance of several feedstock supply system designs. The case study also explores the impact of temporal variations in climate conditions to test the sensitivity of the engineering designs. Results from the case study show that under certain conditions corn stover can be delivered to the cellulosic ethanol biorefinery for $35/dry ton.

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Nitrification in bulk water and biofilms of algae wastewater stabilization ponds

Water Science & Technology ◽

10.2166/wst.2007.354 ◽

2007 ◽

Vol 55 (11) ◽

pp. 93-101 ◽

Cited By ~ 4

Author(s):

M.A. Babu ◽

M.M. Mushi ◽

N.P. van der Steen ◽

C.M. Hooijmans ◽

H.J. Gijzen

Keyword(s):

Model Equation ◽

Bulk Water ◽

Balance Model ◽

Nitrification Rate ◽

Relative Contribution ◽

Activity Test ◽

Stabilization Ponds ◽

Wide Range ◽

Water Columns ◽

Wastewater Stabilization Ponds

Nitrogen removal in wastewater stabilization ponds is poorly understood and effluent monitoring data show a wide range of differences in ammonium. For effluent discharge into the environment, low levels of nitrogen are recommended. Nitrification is limiting in facultative wastewater stabilization ponds. The reason why nitrification is considered to be limiting is attributed to low growth rate and wash out of the nitrifiers. Therefore to maintain a population, attached growth is required. The aim of this research is to study the relative contribution of bulk water and biofilms with respect to nitrification. The hypothesis is that nitrification can be enhanced in stabilization ponds by increasing the surface area for nitrifier attachment. In order to achieve this, transparent pond reactors representing water columns in algae WSP have been used. To discriminate between bulk and biofilm activity, 5-day batch activity tests were carried out with bulk water and biofilm sampled. The observed value for Rnitrbulk was 2.7 × 10−1 mg-N L−1 d−1 and for Rbiofilm was 1,495 mg-N m−2 d −1. During the 5 days of experiment with the biofilm, ammonia reduction was rapid on the first day. Therefore, a short-term biofilm activity test was performed to confirm this rapid decrease. Results revealed a nitrification rate, Rbiofilm, of 2,125 mg-N m−2 d−1 for the first 5 hours of the test, which is higher than the 1,495 mg-N m−2 d−1, observed on the first day of the 7-day biofilm activity test. Rbiofilm and Rnitrbulk values obtained in the batch activity tests were used as parameters in a mass balance model equation. The model was calibrated by adjusting the fraction of the pond volume and biofilm area that is active (i.e. aerobic). When assuming a depth of 0.08 m active upper layer, the model could describe well the measured effluent values for the pond reactors. The calibrated model was validated by predicting effluent Kjeldahl nitrogen of algae ponds in Palestine and Colombia. The model equation predicted well the effluent concentrations of ponds in Palestine.

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Catchment-scale evaluation of pollution potential of urban snow at two residential catchments in southern Finland

Water Science & Technology ◽

10.2166/wst.2013.466 ◽

2013 ◽

Vol 68 (10) ◽

pp. 2164-2170 ◽

Cited By ~ 10

Author(s):

Nora Sillanpää ◽

Harri Koivusalo

Keyword(s):

Snow Water Equivalent ◽

Hydrological Cycle ◽

Cold Climate ◽

Road Maintenance ◽

Catchment Scale ◽

Small Surface ◽

Climate Conditions ◽

Snow Water ◽

High Level ◽

Mass Loads

Despite the crucial role of snow in the hydrological cycle in cold climate conditions, monitoring studies of urban snow quality often lack discussions about the relevance of snow in the catchment-scale runoff management. In this study, measurements of snow quality were conducted at two residential catchments in Espoo, Finland, simultaneously with continuous runoff measurements. The results of the snow quality were used to produce catchment-scale estimates of areal snow mass loads (SML). Based on the results, urbanization reduced areal snow water equivalent but increased pollutant accumulation in snow: SMLs in a medium-density residential catchment were two- to four-fold higher in comparison with a low-density residential catchment. The main sources of pollutants were related to vehicular traffic and road maintenance, but also pet excrement increased concentrations to a high level. Ploughed snow can contain 50% of the areal pollutant mass stored in snow despite its small surface area within a catchment.

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