Sludge characterization at Kadahokwa water treatment plant, Rwanda

2010 ◽  
Vol 10 (5) ◽  
pp. 848-859 ◽  
Author(s):  
A. Uwimana ◽  
I. Nhapi ◽  
U. G. Wali ◽  
Z. Hoko ◽  
J. Kashaigili

A study was carried out to characterize the sludge produced at Kadahokwa Water Treatment Plant (KWTP) in Butare to assess the effectiveness of the sludge treatment and potential impacts of sludge disposal on the environment. Parameters analyzed were chromium, nickel, cadmium, lead, copper, zinc, iron, manganese, aluminium, total nitrogen, total phosphorus, potassium and cation exchange capacity (CEC). The results showed that 450±244.5 tons (dry weight) of sludge are produced annually. The concentrations of heavy metals in the sludge were below the standard limits for land application set by different countries. The high concentrations of nickel (42.3±2.5 ppm), chromium (29.9±6.2 ppm), cadmium (1.1±0.3 ppm) and lead (31.6±3.7 ppm) in the dried sludge posed a pollution risk for the wetland. The CEC was 28.4–33.3 cmol (+)/kg and pH was 6.50–7.45. It was concluded that the KWTP sludge is a poor source of total carbon, a moderate source of nutrients (NPK), and an important source of micronutrients, making it generally suitable for reuse for crop production. The CEC showed that the sludge could improve soil nutrient and water holding capacity. The higher concentration of aluminium (280 ppm) in the sludge creates an opportunity for recycling.

2020 ◽  
Vol 21 (11) ◽  
Author(s):  
Irawati Wahyu ◽  
REINHARD PINONTOAN ◽  
TRIWIBOWO YUWONO

Abstract. Irawati W, Pinontoan R, Yuwono T. 2020. Indigenous copper resistant bacteria isolated from activated sludge of water treatment plant in Surabaya, Indonesia. Biodiversitas 21: 5077-5084. Biological wastewater treatment using activated sludge is a promising wastewater treatment solution for removing heavy metals. To improve the effectiveness of biological wastewater treatment, activated sludge must consist of bacteria that can remove heavy metals through the process of bioaccumulation and biosorption. This study was aimed to isolate indigenous copper resistant bacteria and determining their resistance to copper, as well as analyzing their ability to accumulate and remove copper. Copper resistant bacteria were isolated from activated sludge of water treatment plant in industrial plant in Rungkut, Surabaya. Resistance to copper was analyzed by determining the value of minimum inhibitory concentration (MIC). The ability of bacterial isolates to remove copper was analyzed by atomic absorption spectrophotometer. A total of six highly copper resistant bacteria were isolated and designated as B6.1, C8.1, C9.3, C9.4, C9.5, C10.4 isolates. All isolates were categorized as high resistant bacteria with the MICs of 9-11 mM CuSO4. The two highest copper resistant bacteria were isolates C10.4 and C9.4. The ability of the two isolates to accumulate copper was 8.02 mg and 4.83 mg per gram dry weight of cells and to remove of copper up to 20.45% and 17.66%, respectively.


2018 ◽  
Vol 147 ◽  
pp. 04006 ◽  
Author(s):  
Muhammad Yudha Ramdhani ◽  
M. Rangga Sururi ◽  
Siti Ainun

Leachate is the liquid waste from anaerobic decomposition in a landfill. The ozonation process can be used for leachate treatment. Sludge from sedimentation in water treatment plant contains 5.96% of Al and 9.35% of Si which can affect of its cation exchange capacity and affects the active site in the catalyst. This study aims to determine the effectivity of sludge in the ozonation process to treat leachate. A 1,5 L semi-batch reactor containing 1 L sample was used in this experiment with the rate of oxygen supply was at 4 L/min taken from ambient air. Two groups of sludge weighing 1.5 grams, 3.0 grams and 4.5 grams were used and activate with physically and chemically activated. The best result was obtained by the physically activated sludge with mass of 4.5 gram O3-L-4,5 AF. The differences of removal efficiency between O3-L-4,5 AF with the control (O3) for turbidity were respectively 13.02% and 7.81%, for EC were 10.57% and 8.29%, for COD were 49.44% and 37.50%, and for residual ozone concentration at the end of contact time were 7.6 mg/L and 9.7 mg/L. It can be concluded that activaed sludge and ozonation can be used as a catalyst in leachate treatment.


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.


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