The effects of water quality, epilithic algae and organic matter on communities of stone-dwelling invertebrates in a Hong Kong river

1994 ◽  
Vol 24 (1) ◽  
pp. 327-336
Author(s):  
She Sang Shea
Keyword(s):  
Water Quality ◽  
Organic Matter ◽  
Hong Kong ◽  
Epilithic Algae

Water Quality in the Priority Watercourses of Hong Kong in Respect of Various Environmental Control Measures

1991 ◽  
Vol 23 (1-3) ◽  
pp. 85-91 ◽  
Author(s):  
Ho Kin-chung
Keyword(s):  
Water Quality ◽  
Hong Kong ◽  
Environmental Control ◽  
Control Measures ◽  
Livestock Waste ◽  
Water Control ◽  
Control Zone ◽  
Town Development ◽  
Control Scheme ◽  
Term Monitoring

The water quality in the 12 priority watercourses of Hong Kong was appraised in respect of the various environmental control measures being undertaken. It was noted that water quality in Lam Tsuen River had been significantly improved since 1983. This is attributed to recent resumption of unsewered lands for town development, training of river basin to increase flow, and declaration of the catchment as a “Water Control Zone” under the Water Pollution Control Ordinance. In contrast with the other heavily polluted watercourses to which little abatement measures were implemented, the water qualities of Shing Mun River and Tuen Mun River were slightly upgraded because of the efforts to rectify unauthorized industrial discharges back to foul sewer and provision of interceptors and sewers to villages. The 10 year Livestock Waste Control Scheme enforced on 24 June 1989 was found in parallel with BOD and suspended solids decrease in watercourses. To assess its effectiveness, however, a longer term monitoring is required to get a conclusive result.

Impact of Organic Matter from Stormwater on Water Quality in an Urban River

2015 ◽  
Vol 2015 (9) ◽  
pp. 1462-1481
Author(s):  
Jacob Richardson ◽  
R. Ryan Dupont ◽  
Joan E McLean
Keyword(s):  
Water Quality ◽  
Organic Matter ◽  
Urban River

Study on De-Nitrification of Improved Step-Feed Progress

2014 ◽  
Vol 703 ◽  
pp. 171-174
Author(s):  
Bing Wang ◽  
Yi Xiao ◽  
Shou Hui Tong ◽  
Lan Fang ◽  
Da Hai You ◽  
...  
Keyword(s):  
Water Quality ◽  
Organic Matter ◽  
Fluidized Bed ◽  
Removal Efficiency ◽  
Nitrogen Removal ◽  
Removal Rate ◽  
Operating Conditions ◽  
Removal Mechanism ◽  
Aerobic Zone

Improved step-feed de-nitrification progress combined with biological fluidized bed was introduced in this study. The progress had good performance and capacity of de-nitrification and organic matter. The experiment result showed that the de-nitrification efficiency of the improved biological fluidized bed with step-feed process was higher than the fluidized bed A/O process under the same water quality and the operating conditions. When the influent proportion of each segment was equal, the system showed good nitrogen removal efficiency with the change of influent C/N ratio, HRT and sludge return ratio. The removal rate of TN reached up to 88.2%. It showed that the simultaneous nitrification and de-nitrification phenomenon happened in the aerobic zone. The nitrogen removal mechanism was also studied.

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>

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 Natural organic matter removal by ion exchange at different positions in the drinking water treatment lane

2013 ◽  
Vol 6 (1) ◽  
pp. 1-10 ◽  
Author(s):  
A. Grefte ◽  
M. Dignum ◽  
E. R. Cornelissen ◽  
L. C. Rietveld
Keyword(s):  
Water Quality ◽  
Drinking Water ◽  
Organic Matter ◽  
Water Treatment ◽  
Organic Carbon ◽  
Natural Organic Matter ◽  
Drinking Water Treatment ◽  
Biological Stability ◽  
Sand Filtration ◽  
Slow Sand Filtration

Abstract. To guarantee a good water quality at the customers tap, natural organic matter (NOM) should be (partly) removed during drinking water treatment. The objective of this research was to improve the biological stability of the produced water by incorporating anion exchange (IEX) for NOM removal. Different placement positions of IEX in the treatment lane (IEX positioned before coagulation, before ozonation or after slow sand filtration) and two IEX configurations (MIEX® and fluidized IEX (FIX)) were compared on water quality as well as costs. For this purpose the pre-treatment plant at Loenderveen and production plant Weesperkarspel of Waternet were used as a case study. Both, MIEX® and FIX were able to remove NOM (mainly the HS fraction) to a high extent. NOM removal can be done efficiently before ozonation and after slow sand filtration. The biological stability, in terms of assimilable organic carbon, biofilm formation rate and dissolved organic carbon, was improved by incorporating IEX for NOM removal. The operational costs were assumed to be directly dependent of the NOM removal rate and determined the difference between the IEX positions. The total costs for IEX for the three positions were approximately equal (0.0631 € m−3), however the savings on following treatment processes caused a cost reduction for the IEX positions before coagulation and before ozonation compared to IEX positioned after slow sand filtration. IEX positioned before ozonation was most cost effective and improved the biological stability of the treated water.

scholarly journals Pengaruh Aerasi Injeksi Udara terhadap Beberapa Parameter Kualitas Air di Lokasi Budidaya Ikan Waduk Ir. H. Djuanda

Omni-Akuatika ◽  
2016 ◽  
Vol 12 (3) ◽  
Author(s):  
Lismining Pujiyani Astuti ◽  
Niken TM Pratiwi
Keyword(s):  
Water Quality ◽  
Organic Matter ◽  
Organic Materials ◽  
Fish Farming ◽  
Observation Point ◽  
Organic Matter Decomposition ◽  
Air Injection ◽  
Cage Culture ◽  
Perforated Pipe

Waste of fish farming in floating net are fish feces, urine and undigested feed which is one source of organic matter inputs in Ir. H. Djuanda. Waste organic materials can cause eutrophication of waters. Air injection is one way aeration to increase oxygen to help the process of organic matter decomposition. The purpose of this study was to assess the effect of air injection on some parameters of water quality in fish farming side. This research was conducted at the location of fish farming Ir. H. Djuanda in June-September 2013. Injection of air using a compressor with a pressure of 3 atm as a source of air and perforated pipe at a depth of 3.6 m. Air injection carried out for 8 hours. Observation point vertically at a depth of 3.6 m and horizontally at a distance of -1.5 m (behind the diffuser pipe); 0 (the diffuser pipe); 1.5 m (right and left pipe); +1.5; +3 And +6 m (in front of the pipe diffuser) and a distance of 17 m of pipe which is control. After eight hours of aeration showed that the concentration of organic matter, free carbondioxide, N-NO2 tend to belower in cages aerated but N-NO3 concentration was higher in locations aeration cage than controls cageKeywords: air injection aeration, water quality, fish cage culture, Ir. H. Djuanda Reservoir

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