scholarly journals Identification of significant pressures and assessment of wastewater discharge on Krivaja River water quality

2017 ◽  
Vol 71 (5) ◽  
pp. 407-418
Author(s):  
Vesna Pesic ◽  
Milena Becelic-Tomin ◽  
Djurdja Kerkez ◽  
Bozo Dalmacija ◽  
Dejan Krcmar ◽  
...  
Keyword(s):  
Water Quality ◽  
Risk Assessment ◽  
Organic Matter ◽  
Surface Water ◽  
Impact Assessment ◽  
Water Body ◽  
Suspended Solids ◽  
Municipal Wastewater ◽  
Point Sources ◽  
Wastewater Discharge

One of the key stages of the process of preparing management plans for the river basin is the analysis of pressures and impacts, as well as the risk assessment of failing to achieve the environmental objectives. DPSIR framework (Driving Forces-Pressure-State-Impact-Response) was developed by the European Agency for the environmental protection, and makes the conceptual basis for the pressures and impacts analysis, taking into account the complexity of the interactions in the environment and represents the tool for their analysis. Impact assessment of the water body requires some quantitative information to describe the condition of the water body and/or the pressures that act on it. The aim of the study was to determine the effect of wastewater discharge on Krivaja watercourse. Impact assessment is carried out based on data of polluters? wastewater and monitoring information for water in Krivaja. For each site at which sampling was performed, the specific risk quotients for surface water were calculated, as the ratio of the each pollutant concentration in surface water at the sampling point and environmental quality standards for pollutants, as well as their sum that represents the risk index. In order to have the integrated perceive of processes in the Krivaja River, taking into account cumulative effects from point sources, the concept of total maximum daily load was applied, using which the pollution amount, that can be discharged daily in a water body without degrading his prescribed/required quality, was calculated. Comparison of emitted loads from pollution point sources with maximum allowable ones was performed. Wastewaters of different polluters located on Krivaja are, due to insufficient treatment, very loaded with organic matter and nutrients. Krivaja receives daily 1332 m3 of wastewater, 999 kg COD, 722 kg BOD, 144 kg of nitrogen, 4.3 kg of phosphorus and 627 kg of suspended solids. Of the total wastewater volume, the majority (69%) originates from municipal wastewater, 81% of the total amount of organic matter comes from the industry, while nutrients mostly originate from municipal wastewater. Loading of Krivaja with wastewater is major, uneven and unbalanced. Water quality of Krivaja is unsatisfactory. According to national legislation there is the exceedance of maximum permissible values for Class II for watercourse (good status) for most parameters, in all sampling locations and in both sampling periods. Parameters that exceeded the value for the Class II are dissolved oxygen, organic matter content, suspended solids, nutrients. Water flow in the river is not sufficient to receive the total amount of the pollutant load from point sources. Risk assessment, based on the monitoring results, indicates that the river Krivaja is possibly at risk of failing to meet the required water quality because the most of the values exceeded the limit values.

Monsoon and Post-monsoon Evaluation of Water Quality of Phewa Lake in Pokhara, Midwestern, Nepal

2012 ◽  
Vol 3 (1) ◽  
Author(s):  
Kriti Acharya ◽  
Krishna Raj Tiwari ◽  
Subodh Sharma ◽  
Chiranjibi Prasad Upadhyaya ◽  
Yajna Prasad Timilsina ◽  
...  
Keyword(s):  
Water Quality ◽  
Surface Water ◽  
Electric Conductivity ◽  
Suspended Solids ◽  
Surface Water Quality ◽  
Total Suspended Solids ◽  
Point Sources ◽  
Middle Point ◽  
Post Monsoon ◽  
Significant Difference

The study explored the lake as mesotrophic. Inflow streams to Phewa lake, lake itself and its outflow stream were sampled in monsoon and post-monsoon. Nine different sampling sites were chosen and physico-chemical parameters like pH, temperature, dissolved oxygen, electric conductivity were recorded at the spot and rest of the parameters (total nitrogen, total phosphorus and total suspended solids) were analyzed in the laboratory. The observed concentrations were compared with Standard of Surface water quality for sustaining aquatic life. There was no significant difference in DO level, pH, TSS whereas EC, TN and water temperature showed significant difference with respective seasons. The electric conductivity of Phirke khola (inflow stream to lake) was found high that means it was putting nutrient load to the lake. The total suspended solids were much higher (176 mg/l) at Harpan khola (inflow stream) in monsoon and maximum at the middle point of lake (11 mg/l) in post-monsoon. This showed that the TSS carried by Harpan khola are maximally deposited at middle point of lake and shortening the life of the lake. The study finally recommends controlling the discharge of pollution load and periodic surface water quality monitoring and vertical (depth wise) monitoring is necessary. Keywords - Aquatic Ecology, Wetlands, Point sources, mesotrophic, quality indicators, suspended solids, nutrient input, Phewa Lake, Pokhara, Nepal

Study on the performance of an up-flow aerated biofilter (UAB) in municipal wastewater treatments

1994 ◽  
Vol 30 (11) ◽  
pp. 25-33 ◽  
Author(s):  
Yoshimasa Watanabe ◽  
Satoshi Okabe ◽  
Tomochika Arata ◽  
Yuji Haruta
Keyword(s):  
Organic Matter ◽  
Suspended Solids ◽  
Municipal Wastewater ◽  
Unique Feature ◽  
Aeration Rate ◽  
Loading Rates ◽  
Hydraulic Loading ◽  
Running Cost ◽  
And Performance ◽  
Activated Sludge Systems

A comprehensive wastewater treatment system that accomplishes oxidation of organic matter, nitrification, and denitrification was developed, and its characteristics and performance were investigated. A municipal wastewater was treated by an up-flow aerated biofilter (UAB), in which biofilms were developed on stainless meshes installed horizontally. This UAB exhibited a great potential ability of oxidation of organic matter, SS stabilization, and nitrification due to a unique aeration mechanism giving high DO concentrations with relatively low aeration rates. Another unique feature of the UAB was that attached biofilms on stainless meshes physically filtered out and/or adsorbed suspended solids in the wastewater in addition to the biological oxidation of organic matter. A stable nitrification could be achieved at HRT=10 hours corresponding to a hydraulic loading of 86 L m−2 d−1 and at a ratio of aeration rate to wastewater flow rate (A/W) of 2, which is considerably low as compared to aeration rates of typical activated sludge systems. This UAB system also could handle relatively high hydraulic loading rates. The UAB used in this study still have enough space to install more stainless meshes so as to reduce hydraulic loading rates resulting in the reduction of HRT and aeration rate, which leads to improvement of the system performance as well as reduction of the running cost.

Effects of Fe addition on sediment P dynamics in a eutrophic lake

2021 ◽  
Author(s):  
Melanie Münch ◽  
Rianne van Kaam ◽  
Karel As ◽  
Stefan Peiffer ◽  
Gerard ter Heerdt ◽  
...  
Keyword(s):  
Water Quality ◽  
Organic Matter ◽  
Surface Water ◽  
Water Column ◽  
Sediment Cores ◽  
Surface Water Quality ◽  
Water Interface ◽  
Eutrophic Lakes ◽  
Fe Addition

<p>The decline of surface water quality due to excess phosphorus (P) input is a global problem of increasing urgency. Finding sustainable measures to restore the surface water quality of eutrophic lakes with respect to P, other than by decreasing P inputs, remains a challenge. The addition of iron (Fe) salts has been shown to be effective in removing dissolved phosphate from the water column of eutrophic lakes. However, the resulting changes in biogeochemical processes in sediments as well as the long-term effects of Fe additions on P dynamics in both sediments and the water column are not well understood.</p><p>In this study, we assess the impact of past Fe additions on the sediment P biogeochemistry of Lake Terra Nova, a well-mixed shallow peat lake in the Netherlands. The Fe-treatment in 2010 efficiently reduced P release from the sediments to the surface waters for 6 years. Since then, the internal sediment P source in the lake has been increasing again with a growing trend over the years.</p><p>In 2020, we sampled sediments at three locations in Terra Nova, of which one received two times more Fe during treatment than the other two. Sediment cores from all sites were sectioned under oxygen-free conditions. Both the porewaters and sediments were analysed for their chemical composition, with sequential extractions providing insight into the sediment forms of P and Fe. Additional sediment cores were incubated under oxic and anoxic conditions and the respective fluxes of P and Fe across the sediment water interface were measured.</p><p>The results suggest that Fe and P dynamics in the lake sediments are strongly coupled. We also find that the P dynamics are sensitive to the amount of Fe supplied, even though enhanced burial of P in the sediment was not detected. The results of the sequential extraction procedure for P, which distinguishes P associated with humic acids and Fe oxides, as well as reduced flux of Fe(II) across the sediment water interface in the anoxic incubations, suggest a major role of organic matter in the interaction of Fe and P in these sediments.</p><p>Further research will include investigations of the role of organic matter and sulphur in determining the success of Fe-treatment in sequestering P in lake sediments. Based on these data in combination with reactive transport modelling we aim to constrain conditions for successful lake restoration through Fe addition.</p>

scholarly journals The role of wastewater treatment plants in surface water contamination by plastic pollutants

2018 ◽  
Vol 45 ◽  
pp. 00054 ◽  
Author(s):  
Bozena Mrowiec
Keyword(s):  
Wastewater Treatment ◽  
Surface Water ◽  
Water Contamination ◽  
Membrane Filtration ◽  
Municipal Wastewater ◽  
Wastewater Treatment Plants ◽  
Point Sources ◽  
Municipal Sewage ◽  
Municipal Wastewater Treatment ◽  
Surface Water Contamination

The aim of this paper was to review the literature data regarding the physico-chemical characteristic of plastic pollutants discharged with municipal sewage, the practical possibility of removing microplastic particles from wastewater during different treatment steps in WWTPs and the problem of surface water contamination within them. Microplastics (the size range of 1 nm to < 5 mm), have been recognized as an emerging threat, as well as an ecotoxicological and ecological risk for water ecosystems. Municipal wastewater treatment plants (WWTPs) are mentioned as the main point sources of microplastics in an aquatic environment. Microplastic particles can be effectively removed in the primary treatment zones via solids skimming and sludge settling processes. Different tertiary treatment processes such as: gravity sand filtration, discfilter, air flotation and membrane filtration provide substantial additional removal of microplastics, and the efficiency of wastewater treatment process can be at a removal level of 99.9%. Nevertheless, given the large volumes of effluent constantly discharged to receivers, even tertiary level WWTPs may constitute a considerable source of microplastics in the surface water.

Features of Water Function Zoning of the Surface Water in Sichuan Province

2015 ◽  
Vol 730 ◽  
pp. 221-229
Author(s):  
Rui Kun Cai ◽  
Fu Quan Ni ◽  
Yu Deng
Keyword(s):  
Water Quality ◽  
Surface Water ◽  
Water Resources ◽  
Agricultural Production ◽  
Production Management ◽  
Sichuan Province ◽  
Wastewater Discharge ◽  
Agricultural Wastewater ◽  
Key Points ◽  
Water Quality Deterioration

In this study, based on the water function zoning and the related analyses on the current situations and tendency of the pollutions on water environments in Sichuan province, concluded that the primary cause responsible for the deterioration of water resources is the discharge of agriculture wastewater, and the strengthening of agricultural production management as well as the reduction of the agricultural wastewater discharge are the key points to alleviate the water-quality deterioration.

Suspended particles in the drinking water of two distribution systems

2001 ◽  
Vol 1 (4) ◽  
pp. 237-245 ◽  
Author(s):  
V. Gauthier ◽  
B. Barbeau ◽  
R. Millette ◽  
J.-C. Block ◽  
M. Prévost
Keyword(s):  
Water Quality ◽  
Drinking Water ◽  
Organic Matter ◽  
Distribution System ◽  
Distribution Systems ◽  
Suspended Solids ◽  
Suspended Particles ◽  
Raw Water ◽  
Remote Locations ◽  
Dissolved Matter

The concentrations of suspended particles were measured in the drinking water of two distribution systems, and the nature of these particles documented. The concentrations of particulate matter were invariably found to be small (maximum 350 μg/L). They are globally in the very low range in comparison with dissolved matter concentrations, which are measured in several hundreds of mg/L. Except during special water quality events, such as turnover of the raw water resource, results show that organic matter represents the most important fraction of suspended solids (from 40 to 76%) in treated and distributed water. Examination of the nature of the particles made it possible to develop several hypotheses about the type of particles penetrating Montreal's distribution system during the turnover period (algae skeleton, clays). These particles were found to have been transported throughout the distribution systems quite easily, and this could result in the accumulation of deposits if their surface charge were ever even slightly destabilised, or if the particles were to penetrate the laminar flow areas that are fairly typical of remote locations in distribution systems.

scholarly journals Risk Assessment for the Selected Surface Water Intake

2020 ◽  
Vol 50 (4) ◽  
pp. 147-163
Author(s):  
Dawid Szpak ◽  
Janusz R. Rak ◽  
Krzysztof Boryczko ◽  
Izabela Piegdoń ◽  
Jakub Żywiec
Keyword(s):  
Water Quality ◽  
Risk Assessment ◽  
Drinking Water ◽  
Surface Water ◽  
Water Intake ◽  
Security Measures ◽  
Efficient System ◽  
Factors Affecting ◽  
Risk Definition ◽  
Water Supply Company

AbstractThe purpose of the work is to analyze the risk for surface water intake, taking into account factors affecting the water quality. A three-parameter risk definition was proposed. It was found that the analyzed water intake has an efficient system that protects consumers against drinking water of inadequate quality (multibarier system). The task of the water supply company is to maintain its security measures (including a caution and warning station, biomonitoring) in a state of efficiency.

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