The transformation of aluminium species in the processes of coagulation, sedimentation and filtration

2006 ◽  
Vol 53 (7) ◽  
pp. 225-233 ◽  
Author(s):  
H.Z. Zhao ◽  
H.W. Yang ◽  
Y.T. Guan ◽  
Z.P. Jiang
Keyword(s):  
Removal Rate ◽  
Aluminium Toxicity ◽  
Raw Water ◽  
High Concentration ◽  
Filtration Process ◽  
Chloride System ◽  
System A ◽  
Doc Concentration ◽  
High Turbidity ◽  
Aluminium Species

The aluminium toxicity is closely related to aluminium species. In this work aluminium was fractionated into seven forms: Al(T), Al(Sus), Al(C + S), Al(S), Al(C), Al(O) and Al(I). Four Al-based coagulants and simulated raw water were used in the laboratory to investigate the aluminium transformation in coagulation, sedimentation and filtration processes. It is the use of Al-based coagulants that contributes more to the increase of the residual aluminium for the low-turbidity raw water, while the Al-based coagulants, especially the polymeric aluminium coagulants, work to remove the aluminium from the high-turbidity raw water. In the case of traditional coagulants, the increase of the turbidity or the dissolved organic carbon (DOC) concentration in the raw water results in a high concentration of Al(C + S). The removal rate of aluminium species in the filtration process is not only related to its size: RAl(Sus) > RAl(C + S), RAl(C) > RAl(S), but also to the physicochemical properties of aluminium species and filter. For the kaolin-polyaluminium chloride system, a lower removal rate of aluminium species results is due to the complexation of humic acid and aluminium species.

Suspended Solids Removal Efficiencies of a Barrier Board that Pre-Treats High-Turbidity Raw Water

2012 ◽  
Vol 253-255 ◽  
pp. 969-974
Author(s):  
Jian Liang Chen ◽  
Yi Kuo Chang ◽  
Chin Hsing Lai ◽  
Yun Hwei Shen
Keyword(s):  
Suspended Solids ◽  
Removal Rate ◽  
Initial Period ◽  
Raw Water ◽  
High Concentration ◽  
Solids Concentration ◽  
Gravity Settling ◽  
High Turbidity ◽  
Solids Removal

It tends to produce high-turbidity raw water during the initial period of typhoons or storms and affect the operation of the purifying system. In this research, Raw water suspended solids roughly to 5,000-9,000 mg/l, the removal rate can be to about 70%-90 %, and reduced to 800 mg/l or less, 8 ml/s minimum about 100-400 mg/l. Overall, the quality of effluent water with the overflow water height increased removal rate rose gradually reduce the suspended solids concentration, gravity settling and effective appear, especially the section Ⅳ region (40 cm) removal are more than 80 %, flow 100 ml/s to 84 %, compared with I (10 cm) with 100 ml/s for 74 %, with obvious benefits. The overflow height of the flow of 8 ml/s, and suspended solids by the inlet concentration at 7,400 mg/l to 8,700 mg/l, down to the effluent concentrations are below 300 mg/l, which overflow height of 20, 30, and 40 cm can be reduced to below 200 mg/l, showing that gravitational sedimentation can significantly remove the high concentration of suspended solids.

Research on the Implementation and Analysis of High-Turbidity Raw Water Pre-Treatment with a Barrier Board

2012 ◽  
Vol 610-613 ◽  
pp. 1402-1408
Author(s):  
Jian Liang Chen ◽  
Yi Kuo Chang ◽  
Yun Hwei Shen ◽  
Kun Liao Chen
Keyword(s):  
Removal Rate ◽  
Experimental Result ◽  
Raw Water ◽  
Turbidity Removal ◽  
Gravity Settling ◽  
Bottom Mud ◽  
High Turbidity ◽  
Different Depths ◽  
Pre Treatment

The purpose of this Research is to simulate the water quality of varied High-turbidity Raw Water at different depths under the water’s surface. During the experiment, a Barrier Board was used to extend the flowing route and to change the overflow level for carrying out the pre-treatment of High-turbidity Raw Water through the changes of varied flow rates in order to study the changes and the removal rate of the turbidity for the influent and effluent; with the settled bottom mud surveyed, the operating requirements of the Surface Overflow Rate (SOR). The experimental result indicated that the turbidity of High-turbidity Water can be reduced by means of an inertia restrained flow, extending the flowing route and heightening the overflow level. The results indicated that the turbidity of the effluent was mostly between 380-1,000 NTU in presenting an over 50% removal rate and even up to 93%. When the SOR of the Sedimentation Basin is set at 19.l m/d, a 54-86% turbidity removal rate can be achieved; whereas, a 50-72% removal rate can be achieved when set at 38.3 m/ d. It has indicated that a significant effect could be achieved for turbidity treatment by employing the properties of high-turbidity substances and the convenient physical theory of gravity settling. As such, a visible removal effect could be achieved to exhibit the effect of pre-treatment.

Impact of Raw Water Ammonia on the Surface Water Treatment Processes and Its Removal by Nitrification

1970 ◽  
Vol 24 (2) ◽  
pp. 85-89 ◽  
Author(s):  
M Alamgir Hossain ◽  
ANM Fakhruddin ◽  
Sirajul Islam Khan
Keyword(s):  
Water Quality ◽  
Water Treatment ◽  
Surface Water ◽  
Removal Rate ◽  
Treatment Plant ◽  
Ammonia Removal ◽  
Raw Water ◽  
High Concentration ◽  
Treated Water ◽  
Treatment Processes

Impact of raw water ammonia on the treated water quality and removal of ammonia from surface water were studied. Raw water ammonia and physicochemical quality of treated water of Saidabad Water Treatment Plant were analyzed for the period of one year (January through December 2006). The monthly averages of maximum (7.55 mg/l) and minimum (0.34 mg/l) ammonia-N level of the raw water were recorded in March and September 2006 respectively. During dry season raw water containing high concentration of ammonia reacted with chlorine at pre-chlorination step of treatment processes and disrupted the total treatment system. It was found from the study that when the concentration of ammonia was high in raw water the aesthetic characters such as turbidity, colour, taste, odour, alkalinity, total dissolved solids (TDS), conductivity, total chlorine etc. of the treated water were changed significantly. Chemical consumption is increased as a result water treatment costs is increased. To mitigate the above problems of the treated water nitrification was used for the removal of ammonia from raw water. Ammonia removal rate was monitored with some other water quality parameters during the study. In the nitrification process ammonia was removed from raw water very effectively, i.e., maximum about 98% raw water ammonia was removed during the study. Additionally other water quality factors were improved significantly.Keywords: Raw water, Treated water, Raw water ammonia, Water quality, NitrificationDOI: http://dx.doi.org/10.3329/bjm.v24i2.1249 Bangladesh J Microbiol, Volume 24, Number 2, December 2007, pp 85-89

Research on the Implementation and Analysis of High-Turbidity Raw Water for Particle Pre-Treatment with a Barrier Board

2012 ◽  
Vol 610-613 ◽  
pp. 1432-1438
Author(s):  
Jian Liang Chen ◽  
Yi Kuo Chang ◽  
Yun Hwei Shen ◽  
Kun Liao Chen
Keyword(s):  
Water Quality ◽  
Removal Rate ◽  
Operating Time ◽  
Raw Water ◽  
Detention Time ◽  
Sedimentation Basin ◽  
Large Size ◽  
Treatment Experiment ◽  
High Turbidity ◽  
Pre Treatment

In this research, the raw water presenting turbidity was sampled to simulate the change of the water quality. A barrier board was used to extend the flowing route and the level change of the overflow; carry out the pre-treatment of high-turbidity raw water. Particle detention time and the average flowing speed analyzed as well for comparing the removal effect with that in the physical field. The particle detention time is as follows: At 4-141 min, the operating time can be shortened; when this is less than 90 min, the effluent still can maintain a 50-88% turbidity removal rate and the water quality of the effluent can even drop to 530 NTU. During the test, most of the average flowing speed was within the operating scope of the rectangular Sedimentation Basin for which the removal rate was 61%-93% and the effluent turbidity was below 1,000 NTU and even up to the optimal 380 NTU. A total of 3 items meet the operating requirements of the Inclinometer Sedimentation Basin, presenting a 54%-72% removal rate and 1,000-1,650 NTU of effluent turbidity; and one item exceeds the operating requirements of the Inclinometer Sedimentation Basin, presenting a lowered 1,900 NTU of effluent turbidity from 3,800 NTU and a 50% removal rate. Large-size particles exist in the high-turbidity raw water, which tends to settle under the gravity effect during after a long-route flowing journey. For example, the turbidity of the influent is 4,300-5,300 NTU which was reduced to 920-750 NTU after the pre-treatment experiment presenting a 79-86% or higher removal rate.

Ammonia Removal from Raw Water by using Adsorptive Membrane Filtration Process

2021 ◽  
pp. 118757
Author(s):  
Rosiah Rohani ◽  
Izzati Izni Yusoff ◽  
Nadiah Khairul Zaman ◽  
Arshid Mahmood Ali ◽  
Nadiatul Atalia Balqis Rusli ◽  
...  
Keyword(s):  
Membrane Filtration ◽  
Ammonia Removal ◽  
Raw Water ◽  
Filtration Process ◽  
Adsorptive Membrane

scholarly journals Ti/RuO2-IrO2-SnO2 Anode for Electrochemical Degradation of Pollutants in Pharmaceutical Wastewater: Optimization and Degradation Performances

2020 ◽  
Vol 13 (1) ◽  
pp. 126
Author(s):  
Guozhen Zhang ◽  
Xingxing Huang ◽  
Jinye Ma ◽  
Fuping Wu ◽  
Tianhong Zhou
Keyword(s):  
Removal Rate ◽  
Inorganic Compounds ◽  
Oxide Coating ◽  
X Ray Diffraction ◽  
Pharmaceutical Wastewater ◽  
High Concentration ◽  
Dimensionally Stable Anodes ◽  
X Ray ◽  
Initial Ph ◽  
Cod Removal Rate

Electrochemical oxidation technology is an effective technique to treat high-concentration wastewater, which can directly oxidize refractory pollutants into simple inorganic compounds such as H2O and CO2. In this work, two-dimensionally stable anodes, Ti/RuO2-IrO2-SnO2, have been developed in order to degrade organic pollutants from pharmaceutical wastewater. Characterization by scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), and X-ray diffraction (XRD) showed that the oxide coating was successfully fabricated on the Ti plate surface. Electrocatalytic oxidation conditions of high concentration pharmaceutical wastewater was discussed and optimized, and the best results showed that the COD removal rate was 95.92% with the energy consumption was 58.09 kW·h/kgCOD under the electrode distance of 3 cm, current density of 8 mA/cm2, initial pH of 2, and air flow of 18 L/min.

scholarly journals Heterogeneous Photo-Fenton Catalytic Degradation of Practical Pharmaceutical Wastewater by Modified Attapulgite Supported Multi-Metal Oxides

Water ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 156
Author(s):  
Manjing Lu ◽  
Jiaqi Wang ◽  
Yuzhong Wang ◽  
Zhengguang He
Keyword(s):  
Photocatalytic Oxidation ◽  
Removal Rate ◽  
Catalytic Degradation ◽  
Gas Chromatography Mass Spectrometry ◽  
Pharmaceutical Wastewater ◽  
High Concentration ◽  
Modified Attapulgite ◽  
Cod Removal Rate ◽  
Pre Treatment ◽  
Almost All

Chemical synthetic pharmaceutical wastewater has characteristics of high concentration, high toxicity and poor biodegradability, so it is difficult to directly biodegrade. We used acid modified attapulgite (ATP) supported Fe-Mn-Cu polymetallic oxide as catalyst for multi-phase Fenton-like ultraviolet photocatalytic oxidation (photo-Fenton) treatment with actual chemical synthetic pharmaceutical wastewater as the treatment object. The results showed that at the initial pH of 2.0, light distance of 20 cm, and catalyst dosage and hydrogen peroxide concentration of 10.0 g/L and 0.5 mol/L respectively, the COD removal rate of wastewater reached 65% and BOD5/COD increased to 0.387 when the reaction lasted for 180 min. The results of gas chromatography-mass spectrometry (GC-MS) indicated that Fenton-like reaction with Fe-Mn-Cu@ATP had good catalytic potential and significant synergistic effect, and could remove almost all heterocycle compounds well. 3D-EEM (3D electron microscope) fluorescence spectra showed that the fluorescence intensity decreased significantly during catalytic degradation, and the UV humus-like and fulvic acid were effectively removed. The degradation efficiency of the nanocomposite only decreased by 5.8% after repeated use for 6 cycles. It seems appropriate to use this process as a pre-treatment for actual pharmaceutical wastewater to facilitate further biological treatment.

Rapidly extracted (0.02 M CaCl2-soluble) reactive aluminum as a measure of aluminum toxicity in soils

Soil Research ◽  
1989 ◽  
Vol 27 (4) ◽  
pp. 663 ◽  
Author(s):  
EA Close ◽  
HKJ Powell
Keyword(s):  
Salicylic Acid ◽  
White Clover ◽  
Aluminum Toxicity ◽  
Maximum Yield ◽  
Acid Soils ◽  
Aluminium Toxicity ◽  
Field Method ◽  
Colorimetric Analysis ◽  
Aluminium Species

This paper examines the use of short extraction times, and the determination of aluminium with chrome azurol S (CAS), for the estimation of 0.02 M CaCl2-soluble aluminium in soils. It reports the correlation between CAS-reactive aluminium in 5 min extracts and percent maximum yield of white clover (Trifolium repens) for a series of acid soils. The reactivity of soluble and colloidal aluminium species with the metallochromic reagent CAS has been assessed. ~ l ( a q ) ~ + , simple hydroxy species and complexes of weakly binding ligands (salicylic acid, tannins) are CAS-reactive (2 rnin). In contrast, complexes of strongly binding ligands (citric acid, fulvic acid) are not CAS-reactive ([Al] ~ [L] ~ [CAS] ~ 1-2~10-5 M). For a series of six limed phosphated topsoils and subsoils (pH 4.2-5.5), 0.02 M CaCl2- soluble aluminium, as determined with CAS, was negatively correlated against the percent maximum yield of white clover; r2 = -0.73** (5 min extraction), n = 20. This correlation is similar to that for yield against total aluminium as determined by atomic absorption spectroscopy after 60 min extraction (r2 = -0.77**). However, the colorimetric analysis is more convenient and sensitive; further, it does not measure colloidal and polymeric aluminium species (which may not be plant-available). The satisfactory correlation achieved for short extraction times suggests use of CAS for a rapid field method for aluminium toxicity in soils.

scholarly journals Pyromorphite formation from montmorillonite adsorbed lead

Mineralogia ◽  
2011 ◽  
Vol 42 (2-3) ◽  
pp. 75-91 ◽  
Author(s):  
Tomasz Bajda ◽  
Tomasz Marchlewski ◽  
Maciej Manecki
Keyword(s):  
Ion Exchange ◽  
Aqueous Solutions ◽  
Phosphate Concentration ◽  
High Concentration ◽  
Exchange Effect ◽  
System A ◽  
New Phase

Pyromorphite formation from montmorillonite adsorbed lead The reaction of Pb-adsorbed montmorillonite with aqueous solutions of PO4 and Cl ions results in the decrease in phosphate concentration associated with the formation of a new phase - pyromorphite Pb5(PO4)3Cl. Pyromorphite crystals range in size from hundreds of nm to several tens of μm, depending on the PO4, K, and Ca concentrations in the reacting system. A strong ion-exchange effect of K+ and Ca2+ cations on desorption of Pb2+ from Pb-adsorbed montmorillonite was observed. Also, a high concentration of cations leads to a rapid desorption of Pb and the formation of fine pyromorphite crystals. In contrast, low PO4, K and Ca concentrations result in the formation of relatively large euhedral crystals. Final Pb concentrations are much lower in experimental sets than in control experiments with no phosphate present.

BEHAVIOR-BASED ACTIVE VISION

1994 ◽  
Vol 08 (06) ◽  
pp. 1493-1526
Author(s):  
CLAUDIO S. PINHANEZ
Keyword(s):  
Vision System ◽  
Active Vision ◽  
Implementation Process ◽  
High Concentration ◽  
Subsumption Architecture ◽  
System A ◽  
Saccadic Movement ◽  
Building Process ◽  
Sensor Structure ◽  
Behavior Based

A vision system was built using a behavior-based model, the subsumption architecture. The so-called active eye moves the camera’s axis through the environment, detecting areas with high concentration of edges, with the help of a kind of saccadic movement. The design and implementation process is detailed in the article, paying particular attention to the fovea-like sensor structure which enables the active eye to efficiently use local information to control its movements. Numerical measures for the eye’s behavior were developed, and applied to evaluate the incremental building process and the effects of the saccadic movements on the whole system. A higher level behavior was also implemented, with the purpose of detecting long straight edges in the image, producing pictures similar to hand drawings. Robustness and efficiency problems are addressed at the end of the paper. The results seem to prove that interesting behaviors can be achieved using simple vision methods and algorithms, if their results are properly interconnected and timed.

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