scholarly journals Effects of Phosphate on Nitrifying Activity in a Water Treatment Plant at Low Temperature.

2002 ◽  
Vol 38 (1) ◽  
pp. 21-28 ◽  
Author(s):  
TAKAYUKI NISHIO ◽  
TARO YOSHIKURA ◽  
ISAO FUKUNAGA
2011 ◽  
Vol 6 (2) ◽  
Author(s):  
C. Jeuch-Trommsdorff ◽  
A. Benz ◽  
R. Moser ◽  
A. Ulli

A common valorization of digester gas and composting gas increases the efficiency of the co-generator installation by 10% to 15%. In this case study, a green waste fermentation and composting platform and its neighboring waste water treatment plant (WWTP) opted for a common co-generator: about 600,000 m3 of digester gas and 1,900,000 m3/year of fermentation gas (biogas) transformed into electricity and heat. The energy content of this combined gas source is about 13,800 MW/a, out of which about 38% is transformed into electricity, about 42% is converted into heat, and 20% is lost. The electrical energy produced (600 kW) is sold to the Swiss electrical grid (Swissgrid Program) as Ökostrom, or “green power,” at a higher price than that of normal power. The heat produced (660 kWh) is used to heat the composter (60 kWh), the digester (125 kWh), and the buildings (25 kW). The excess heat (450 kWh) could also be used for a future low-temperature biosolids drying project, whose life-cycle costs would be counterbalanced by the reduction in disposal costs. This project allows for an optimal use of the energy content of biogas and digester gas. Once drying is implemented, the environmental impact will be even more beneficial with a reduction in transport and the facilitation of phosphorous recovery from dried biosolids. In this case study, the large amount of biogas produced would enable the implementation of low-temperature biosolids drying using the excess heat of the co-gen facilities. The ratio of the biogas to the digester gas production has to be at least 2.5 to 3.0 in order to produce sufficient excess heat for a low-temperature dryer. Low-temperature drying is the most ecological and sensible way of using locally produced waste-heat all year long.


Author(s):  
Fuguo Qiu ◽  
Huadong Lv ◽  
Xiao Zhao ◽  
Dongye Zhao

Climate change has often caused failure in water treatment operations. In this study, we report a real case study at a major surface water treatment plant in Alabama, USA. Following a severe winter storm, the effluent water turbidity surged to >15.00 Nephelometric Turbidity Units (NTU), far exceeding the 0.30 NTU standard. As a result, the plant operation had to be shut down for three days, causing millions of dollars of losses and affecting tens of thousands of people. Systematic jar tests were carried out with sediment samples from 22 upstream locations. The coagulation and settleability of sediment particles were tested under simulated storm weather conditions, i.e., low temperature (7 °C) and in the presence of various types and concentrations of natural organic matter (NOM) that was extracted from the local sediments. Experimental results proved that elevated NOM (6.14 mg·L−1 as Total Organic Carbon, TOC) in raw water was the root cause for the failure of the plant while the low temperature played a minor but significant role. Pre-oxidation with permanganate and/or elevated coagulant dosage were found effective to remove TOC in raw water and to prevent similar treatment failure. Moreover, we recommend that chemical dosages should be adjusted based on the TOC level in raw water, and a reference dosage of 0.29 kg-NaMnO4/kg-TOC and 19 kg- polyaluminum chloride (PACl) /kg-TOC would be appropriate to cope with future storm water impacts. To facilitate timely adjustment of the chemical dosages, the real time key water quality parameters should be monitored, such as turbidity, TOC, Ultraviolet (UV) absorbance, pH, and color. The findings can guide other treatment operators to deal with shock changes in the raw water quality resulting from severe weather or other operating conditions.


2019 ◽  
Vol 10 (1) ◽  
pp. 16
Author(s):  
V. MANE-DESHMUKH PRASHANT ◽  
B. MORE ASHWINI ◽  
B. P. LADGAOKAR ◽  
S. K. TILEKAR ◽  
◽  
...  

2017 ◽  
Vol 16 (10) ◽  
pp. 2303-2315 ◽  
Author(s):  
Djamel Ghernaout ◽  
Abdelmalek Badis ◽  
Ghania Braikia ◽  
Nadjet Mataam ◽  
Moussa Fekhar ◽  
...  

2008 ◽  
Author(s):  
Angelina Johnston ◽  
Kevin O'Connor ◽  
Todd Criswell

2001 ◽  
Vol 1 (3) ◽  
pp. 91-96 ◽  
Author(s):  
L.J. Hem ◽  
E.A. Vik ◽  
A. Bjørnson-Langen

In 1995 the new Skullerud water treatment plant was put into operation. The new water treatment includes colour removal and corrosion control with an increase of pH, alkalinity and calcium concentration in addition to the old treatment, which included straining and chlorination only. Comparative measurements of internal corrosion were conducted before and after the installation of the new treatment plant. The effect of the new water treatment on the internal corrosion was approximately a 20% reduction in iron corrosion and a 70% reduction in copper corrosion. The heavy metals content in standing water was reduced by approximately 90%. A separate internal corrosion monitoring programme was conducted, studying the effects of other water qualities on the internal corrosion rate. Corrosion coupons were exposed to the different water qualities for nine months. The results showed that the best protection of iron was achieved with water supersaturated with calcium carbonate. Neither a high content of free carbon dioxide or the use of the corrosion inhibitor sodium silicate significantly reduced the iron corrosion rate compared to the present treated water quality. The copper corrosion rate was mainly related to the pH in the water.


2002 ◽  
Vol 2 (1) ◽  
pp. 233-240 ◽  
Author(s):  
J. Cromphout ◽  
W. Rougge

In Harelbeke a Water Treatment Plant with a capacity of 15,000 m3/day, using Schelde river water has been in operation since April 1995. The treatment process comprises nitrification, dephosphatation by direct filtration, storage into a reservoir, direct filtration, granular activated carbon filtration and disinfection. The design of the three-layer direct filters was based on pilot experiments. The performance of the plant during the five years of operation is discussed. It was found that the removal of atrazin by activated carbon depends on the water temperature.


1991 ◽  
Vol 24 (10) ◽  
pp. 161-170 ◽  
Author(s):  
M. D. Sinke

Until a century ago, The Hague's waste water was discharged directly into the city's canals. However, the obnoxious smell and resultant pollution of local waters and beaches then necessitated the implementation of a policy of collecting and transferring waste water by means of a system of sewers. By 1937, it was being discharged, via a 400 metre-long sea outfall, directly into the North Sea. By 1967, however, the increasing volume of waste water being generated by The Hague and the surrounding conurbations called for the construction of a primary sedimentation plant. This had two sea outfalls, one 2.5 km long and the other 10 km long, the former for discharging pre-settled waste water and the latter for discharging sludge directly into the North Sea. This “separation plant” was enlarged during the period 1986-1990. On account of the little available area - only 4.1 ha - the plant had to be enlarged in two stages by constructing a biological treatment section and a sludge treatment section with a capacity of 1,700,000 p.e. (at 136 gr O2/p.e./day). In order to gain additional space, a number of special measures were introduced, including aerating gas containing 90% oxygen and stacked final clarifiers. Following completion of the sludge treatment section, it has become possible, since 1st May 1990, to dump digested sludge into a large reservoir (“The Slufter”), specially constructed to accommodate polluted mud dredged from the Rotterdam harbours and waterways. As a result of these measures, there has been a reduction of between 70% and 95% in North Sea pollution arising from the “Houtrust” waste water treatment plant. Related investment totalled Dfl. 200 million and annual operating and maintenance costs (including investment charges) will amount to Dfl. 30 million. Further measures will have to be taken in the future to reduce the discharge of phosphorus and nitrogen. So this enlargement is not the end. There will be continued extension of the purification operations of the “Houtrust” waste water treatment plant.


Sign in / Sign up

Export Citation Format

Share Document