Experimental Studies on Enhanced Coagulation of Tail Water

2013 ◽  
Vol 295-298 ◽  
pp. 1478-1481
Author(s):  
Feng Xun Tan ◽  
Jiu Mei Wang ◽  
Dao Ji Wu

Traditional wastewater treatment methods can no longer remove effectively nitrogen and phosphorus that are the direct murderers of water eutrophication hazard. Enhanced coagulation method was adopted to improve the treatment effect by dosing suitable coagulants and coagulant aids. The raw water was from the reclaimed water in a University. TP and ammonia nitrogen removal of the water had been researched through an enhanced coagulation process with dosing ferric chloride, aluminum sulfate, polymeric ferric chloride, and poly-aluminum chloride (PAC) in this study. The coagulants effects were estimated by determining the removal rate of ammonia nitrogen, TP, COD and turbidity. When dosing the raw water with 80 mg/L PAC, the removal rates of ammonia nitrogen, TP, COD and turbidity are respectively 6.12%, 67.79%, 26.21%, 85.41%. The experimental results can be used as a reference of water treatment in the reclaimed water station.

2013 ◽  
Vol 361-363 ◽  
pp. 785-788
Author(s):  
Xiao Jie Wang ◽  
Xiao Jing Li ◽  
Shuang Wang ◽  
Yun Zhe Ji

The influences of coagulant species, dose, water turbidity, and pollution situation of raw water on the results of enhanced coagulation have been investigated targeted at water contaminated by chemical agent. Ferric trichloride and polymeric aluminum ferric chloride (PAFC) acted as coagulant, poly dimethyl diallyl ammonium chloride (HCA) worked as coagulant aid and paraoxon acted as simulation agent of chemical agent VX in this process. The results show that: enhanced coagulation process cannot remove effectively chemical agent (paraoxon) in raw water; the result of treatment by PAFC and PAFC+HCA is better than that by FeCl3 and FeCl3+HCA; the addition of certain amount of HCA based on the condition that coagulant has been added will improve removal rate of both chemical agent and turbidity; the bigger the turbidity of raw water is, the higher the removal rate of paraoxon will be.


2019 ◽  
Vol 80 (9) ◽  
pp. 1763-1773 ◽  
Author(s):  
Chuanmin Chen ◽  
Yu Wang ◽  
Songtao Liu ◽  
Rongrong Feng ◽  
Xingjia Gu ◽  
...  

Abstract A biological method was developed for reusing urban reclaimed water in circulating cooling water systems (CCWS), in which the compound microorganism preparation (CMP) mainly included nitrobacteria, Bacillus subtilis, photosynthetic bacteria and Thiobacillus denitrificans, was used to control the scaling, corrosion and biofouling of CCWS. The abundant carbon, nitrogen and phosphorus in urban reclaimed water met the needs of microbial growth. Compared with chemical agents, CMP had the advantages of high efficiency, no additional chemicals and being more economical. The research results showed that CMP improved water quality and decreased ammonia nitrogen (NH3-N) and chemical oxygen demand (COD). The concentration ratio of CCWS reached 3.87 using CMP. The corrosion inhibition rate of CMP and the removal rate on biofouling achieved 99.69% and 22.21%, respectively. The mechanisms of CMP to control scaling, corrosion and biofouling were discussed, and the surface characteristics and chemical compositions of corrosion products and biofouling were analyzed.


Author(s):  
Yu Li ◽  
Leigang Li ◽  
Reham Yasser Farouk ◽  
Yuanyuan Wang

Flocculation can remove large amounts of nitrogen and phosphorus from wastewater, and the resulting nitrogen- and phosphorus-rich floc can be used to produce organic fertilizer. For biogas slurries containing high levels of nitrogen and phosphorus, ordinary flocculants can no longer meet the flocculation requirements. In this study, to fully utilize the advantages of the two flocculants and achieve efficient removal rates of nitrogen and phosphorus from a biogas slurry, chitosan (CTS) and polyaluminum chloride (PAC) were used as a composite flocculation agent to flocculate pig biogas slurries. The response surface method was used to study the effect of PAC added (PACadded) to the composite flocculant (CF), composite flocculant added (CFadded) to the biogas slurry and the pH on flocculation performance, and optimize these three parameters. In the tests, when the PACadded was 6.79 g·100 mL−1CF, the CFadded was 20.05 mL·L−1 biogas slurry and the pH was 7.50, the flocculation performance was the best, with an absorbance of 0.132 at a wavelength of 420 nm. The total phosphorus (TP) concentration was reduced from 214.10 mg·L−1 to 1.38 mg·L−1 for a removal rate of 99.4%. The total ammonia nitrogen (TAN) concentration was reduced from 1568.25 mg·L−1 to 150.27 mg·L−1 for a removal rate of 90.4%. The results showed that the CF could form larger flocs, and had greater adsorption capacity and more stable flocculation performance than ordinary flocculants. Furthermore, the CF could exhibit better chelation, electrical neutralization and bridge adsorption.


2010 ◽  
Vol 62 (2) ◽  
pp. 330-339 ◽  
Author(s):  
Y. J. Zhang ◽  
X. L. Zhao ◽  
X. X. Li ◽  
Ch. Liu ◽  
L. L. Zhu

The enhanced coagulation of algae-rich raw water from Lake Taihu in summer was studied by use of composite coagulants. The composite coagulants were composed of polyaluminum chloride (PAC) and polydimethyldiallylammonium chloride (PDM) with various intrinsic viscosity values (0.55–3.99 dL/g) and different mass percentages (5–20%) in the formulation. For raw water with temperature of 28–29°C and algae content of 3.60 × 104–3.70 × 104 cells/ml, the algae-removal rates of 89.0% and 89.3–93.1% could be realized by using PAC and PAC/PDM (0.55/5%–3.99/20%) with dosages of 8.37 mg/L and 5.93–3.58 mg/L, respectively, when 2 NTU residual turbidity of treated water after sedimentation was required. Compared with using PAC only, the removal rate of CODMn using PAC/PDM increased at least 4.4% when the dosage was 8 mg/L, and increased at least 5.0% when the dosage was 10 mg/L. The composite coagulants could still function well when raw water quality deteriorated and algae content reached 8.00 × 104 cells/ml. The enhanced coagulation efficiency of PAC/PDM (0.55/5%) could be better than that of PAC combined with prechlorination process when the same dosages are used.


2014 ◽  
Vol 955-959 ◽  
pp. 360-365
Author(s):  
Min Han ◽  
Cheng Hong Feng ◽  
Shun Li Wang ◽  
Ye Quan Fu ◽  
Li Qing An ◽  
...  

To explore purification approach of anaerobic-digested-slurry from cattle dung, this study translated a technology in inorganic coagulation. Under the same condition, a coagulation experiment was carried out by three kinds inorganic coagulants such as polyaluminium chloride (PAC), aluminum sulfate and ferric chloride, respectively, then measured indicators of pH value, BOD5 value, CODcr value, ammonia nitrogen value, turbidity value. Results showed that there was a varying degree of purification effect, and the removal rate of the above indicators increased as the coagulant dosage increasing, the ferric chloride with the dosage of 960mg/L was the best one in purifying effect among the three coagulants. It is feasible that coagulation technology was used to pretreatment biogas slurry from cattle dung, and most of the indicators reached Chinese national standard basically (GB 18596-2001).


2012 ◽  
Vol 588-589 ◽  
pp. 55-58
Author(s):  
Yong Feng Li ◽  
Jian Yu Yang ◽  
Guo Cai Zhang

Simulate sewage were used in an anaerobic-anoxic-aerobic biological nutrient removal system(A2O process), by observing the pHs in different compartments and its reflected changes in nitrogen and phosphorus removal, studied on the effects of different pHs on the removal of pollutants. The experiments indicates that the anaerobic phosphorus release showed the main performance of the decline of pH, denitrification in anoxic zone caused the rise of pH, uptake of phosphate in the aerobic zone mainly caused the continuous rise of pH. There is no evidently changes in COD removal, ammonia nitrogen get the highest removal as the pH value was between 8.0-8.5, when pH was at 6.5-7.5, the TN have the maximum removal rate, TP can keep in a high level when the pH was above 6.0.


2010 ◽  
Vol 113-116 ◽  
pp. 735-739
Author(s):  
Xing Bin Sun ◽  
Fu Yi Cui ◽  
Zhao Chao Hou ◽  
Lin Meng

Chironomus kiiensis larvae which cannot be exterminated by conventional disinfection process propagates prolifically in eutrophic water body, and it therefore turns to be a potential problem encountered in drinking water quality. In this work, the quantitative experimental studies were carried out on removal of Chironomus kiiensis larvae in raw water by coagulation-sedimentation process. The coagulation jar test showed that the Chironomus kiiensis larvae could be partially removed from water by coagulation-sedimentation process. Based on it, removal effect of pre-oxidation combined with coagulation-sedimentation process on Chironomus kiiensis larvae was evaluated. The results showed that chlorine dioxide pre-oxidation possessed better removal performance than prechlorinion, and Chironomus kiiensis larvae in the raw water could be completely removed by chlorine dioxide pre-oxidation in combination with the coagulation-sedimentation process at chlorine dioxide dosage of 0.8mg/L. The pH in the range of 6-8 did not affect the inactivation efficiency of chlorine dioxide, whereas pH 10 resulted in around 10% decrease in removal rate. Meanwhile, the removal rate of Chironomus kiiensis larvae improved with the temperature increasing within the range investigated of 15-30°C. The removal rate was reduced by 6.7% when temperature reduced from 30°C to 15°C.


2021 ◽  
Vol 2021 ◽  
pp. 1-14
Author(s):  
Tingyu Fan ◽  
Miao Wang ◽  
Xingming Wang ◽  
Yingxiang Chen ◽  
Shun Wang ◽  
...  

Nitrogen and phosphorus are commonly recognized as causing eutrophication in aquatic systems, and their transport in subsurface environments has also aroused great public attention. This research presented four natural clay minerals (NCMs) evaluated for their effectiveness of NH4+ and PO43- adsorption from wastewater. All the NCMs were fully characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), BET analysis, and adsorption kinetics and isotherms to better understand the adsorption mechanism-property relationship. The results show that the adsorption efficiency of the four NCMs for phosphate was better than that for ammonia nitrogen. The removal rate of phosphate was higher than 65%, generally in the range of 80%-90%, while the removal rate of ammonia nitrogen was less than 50%. The adsorption kinetic behavior followed the pseudo-second-order kinetic model. The ammonia nitrogen adsorption isotherm was in good agreement with the Freundlich isotherm equilibrium model, and the phosphate adsorption isotherm matched the Langmuir model. Among all the NCMs studied, bentonite (7.13 mg/g) and kaolinite (5.37 mg/g) showed higher adsorption capacities for ammonia nitrogen, while zeolite (0.21 mg/g) and attapulgite (0.17 mg/g) showed higher adsorption capacities for phosphate. This study provides crucial baseline knowledge for the adsorption of nitrogen and phosphate by different kinds of NCMs.


PLoS ONE ◽  
2021 ◽  
Vol 16 (2) ◽  
pp. e0246841
Author(s):  
Long Yun ◽  
Wei Wang ◽  
Yingying Li ◽  
Mei Xie ◽  
Ting Chen ◽  
...  

In recent years, marine red yeasts have been increasingly used as feed diets for larviculture of aquatic animals mainly due to their rich nutrition and immunopotentiation, however little attention is given to their other probiotic profits. In this study, a marine red yeast strain YLY01 was isolated and purified from farming water and it was identified as a member of Rhodosporidiums sphaerocarpum by the phylogeny based on 18S rDNA sequence. The strain YLY01 could effectively remove ammonia nitrogen from an initial 9.8 mg/L to 1.3 mg/L in 48 h when supplemented with slight yeast extract and glucose in water samples and the removal rate of ammonia nitrogen was up to 86%. Shrimps (Litopenaeus vannamei) in experimental group incubated with the yeast YLY01 exhibited a higher survival rate than those in blank control group and positive control group challenged by Vibrio harveyi, and it manifested that the strain has high biosecurity to at least shrimps. The strain YLY01 could inhibit the growth of Vibrio cells when a small quantity of carbon source was added into farming water. In addition, a nutrition composition assay showed the contents of protein, fatty acids, and total carotenoids of the yeast YLY01 were 30.3%, 3.2%, and 1.2 mg/g of dry cell weight, respectively. All these results indicated that the marine red yeast YLY01 has a great potential to be used as a versatile probiotic in aquaculture and to be developed as a microbial agent for high-ammonia tail water treatment.


2010 ◽  
Vol 178 ◽  
pp. 137-142
Author(s):  
Hong Han ◽  
Xu Gu ◽  
Jin Long Jiang ◽  
Dong Li ◽  
Wen Wang

Attapulgite clay and Poly aluminum chloride (PAC) combination process was adopted for enhanced coagulation on micro-polluted raw water, TOC and NH3-N served as water quality indexes. Results showed that, when the dosage of PAC was 15 mg/L and the dosage of attapulgite clay after 350 °C heat modification was 200 mg/L, the removal rates of TOC and NH3-N reached 82.5% and 75.3% respectively under optimal cogulation conditions, which increased by 72.2% and 230.3% respectively compared with traditional PAC process, and spared 1/4 of PAC dosage. Attapulgite clay and PAC enhenced process reflected advantages of low cost, easy handling, high removal rate, accelerated settlement, sludge reduction, less residual aluminium, chemical and biological safety, and so on. Its application in water supply treatment field was in good prospect.


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