Research on the Preparation of Polyferric Silicate Chloride (PFSC) and Application on Algae Wastewater Treatment

2010 ◽  
Vol 154-155 ◽  
pp. 230-234 ◽  
Author(s):  
Li Ping Wang ◽  
Xiao Fei Yan ◽  
Xia Xu ◽  
Ai Bin Xu ◽  
Nai Yuan Gao
Keyword(s):  
Wastewater Treatment ◽  
Reaction Time ◽  
Chlorophyll A ◽  
Influencing Factors ◽  
Sodium Silicate ◽  
Silicic Acid ◽  
Raw Materials ◽  
Coagulation Performance ◽  
Coagulation Mechanism ◽  
Removal Efficiencies

A new polyferric silicate chloride(PFSC) was prepared by using sodium silicate, ferric chloride as raw materials, at the same time, its coagulation performance and the influencing factors were observed. The water containing algae was processed by PFSC coagulant and coagulation mechanism were discussed. The results showed that the best reaction time of PFSC preparation was 1h, temperature was 40°Cand Fe/Si mole ratio was 1. The removal efficiencies of chlorophyll a and turbidity were 82.40% and 94.97% respectively at 14mgFe•L-1 of dosage. Coagulation mechanism of PFSC is considered as the cooperation of oxidization/adsorption/charge-neutralization, adsorption-bridging and sweeping, which is the effect of silicic acid, iron and iron hydrolysate on the suspended particles in wastewater.

Research on the Preparation and Turbidity Removal Efficiency of Polysilicate Iron and Zinc(PSFZn) Coagulant

2011 ◽  
Vol 233-235 ◽  
pp. 537-540
Author(s):  
Li Ping Wang ◽  
Ai Bin Xu ◽  
Xia Xu ◽  
Er Deng Du ◽  
Xiao Fei Yan
Keyword(s):  
Reaction Time ◽  
Removal Efficiency ◽  
Raw Materials ◽  
Preparation Condition ◽  
Molar Ratio ◽  
Turbidity Removal ◽  
Coagulation Performance ◽  
Coagulation Mechanism ◽  
Iron And Zinc ◽  
Combined Action

A new coagulant polysilicate iron and zinc (PSFZn) was prepared by using sodium silicate, inorganic acid, ferric chloride, zinc chloride as raw materials, the factors of (Fe+Zn):Si molar ratio, Fe:Si molar ratio, reaction temperature, reaction time and the dosage on coagulation performance were tested. The results showed that the best preparation condition of PSFZn were 60min of reaction time preparation, 30°C of temperature and 4:2:3 of n(Fe):n(Zn):n(SiO2). When the dosage was 0.4mL·L-1, the removal efficiency of turbidity was the best which could reach 98.07%. At the same time, it could be concluded that the coagulation mechanism of PSFZn was the combined action of the electric neutralization, the adsorption bridging and sticks the attachment to sweep, which was also the action of the silicic acid, the metal ions and the ions hydrolysate to the muddy colloid pellet in the simulated water sample.

scholarly journals Preparation of composite coagulant of PFM-PDMDAAC and its coagulation performance in treatment of landfill leachate

2015 ◽  
Vol 5 (2) ◽  
pp. 177-188 ◽  
Author(s):  
Simin Li ◽  
Yongkang Lv ◽  
Zhanmeng Liu
Keyword(s):  
Landfill Leachate ◽  
Raw Materials ◽  
Oxygen Demand ◽  
X Ray Diffraction ◽  
Mechanical Mixing ◽  
Coagulation Performance ◽  
Coagulation Mechanism ◽  
As Adsorption ◽  
Co Precipitation ◽  
Composite Coagulant

A novel inorganic–organic composite coagulant, poly-ferric-magnesium (PFM) polydimethyldiallylammonium chloride (PDMDAAC), was prepared using FeSO4, MgSO4 and PDMDAAC as raw materials and was introduced to treat landfill leachate. The coagulation performance of the new reagent was evaluated and compared with those of other coagulants. The new reagent was characterized in terms of the analysis of ferron-timed spectroscopy, X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR). The coagulation mechanism was investigated by measuring the ζ-potential reduction and chemical oxygen demand removal at different dosages. Coagulation experiments revealed that the new reagent exhibited better coagulation performance compared with the simple PFM and the PFM + PDMDAAC. Ferron-timed spectroscopy showed that the new reagent exhibited increased effective polymer species concentration. XRD and FTIR spectroscopy showed that the new reagent was not a simple mechanical mixing of PFM and PDMDAAC, but a composite system with inorganic–organic complex interpenetration networks. The predominant coagulation mechanism of the new reagent was charge neutralization at low dosages, as well as adsorption bridging and co-precipitation netting at high dosages, when treating landfill leachate.

Production of Lightweight Ceramsite from the Yellow River Silt and its Performance Investigation in a Biological Aerated Filer (BAF) Reactor

2013 ◽  
Vol 699 ◽  
pp. 829-834 ◽  
Author(s):  
Shan Ping Li ◽  
Xiao Hong Cao ◽  
Xiang Ru Ma ◽  
Jie Xu ◽  
Yan Wen Dong
Keyword(s):  
Wastewater Treatment ◽  
Sodium Silicate ◽  
Hydraulic Retention Time ◽  
Yellow River ◽  
The Yellow River ◽  
Curing Time ◽  
Hospital Wastewater ◽  
Sintering Process ◽  
Operation Condition ◽  
Removal Efficiencies

This study discussed the possibility of employing the Yellow River Silt (YRS) as the starting materials to produce lightweight ceramisite (LWC) by a non-sintering process. Cement and sodium silicate were used as additives. The performance of the LWC serving as a biomedium in a biological aerated reactor (BAF) for hospital wastewater treatment was investigated and the optimum operation condition was studied. Results presented that: (1) YRS could be used to prepare the LWC under the propitious condition (the ratio of YRS to cement was 75:25, the percentage of sodium silicate was 7% and the curing time was 5 d); (2) LWC could be used as a packing medium in the BAF. The BAF has large removal efficiencies on COD¬cr and NH3-N when the hydraulic retention time (HRT), the ratio of air to liquid (A/L) and the height of packing medium were 6 h, 5:1 and 80 cm respectively.

The Effect of Preparation Method of Precursor on Synthesis of BiFeO3 by a Hydrothermal Method

2014 ◽  
Vol 906 ◽  
pp. 178-182
Author(s):  
Yang Xiao ◽  
Zhen Zhu Cao ◽  
Ru Yi Shao ◽  
Wei Yan He ◽  
Yan Fang Gao ◽  
...  
Keyword(s):  
Reaction Time ◽  
Hydrothermal Method ◽  
Influencing Factors ◽  
Preparation Method ◽  
Raw Materials ◽  
Bismuth Ferrite ◽  
Precipitation Method ◽  
Molar Ratio ◽  
Precipitation Process ◽  
Co Precipitation

The precursor of bismuth ferrite BiFeO3 powders were prepared by the normal co-precipitation and reversed co-precipitation method. The key influencing factors including the reaction time, the concentration of mineralizer and the molar ratio of raw materials in the normal co-precipitation are systematically studied. Pure BiFeO3 powder has been obtained by adjusting the molar ratio of raw materials. Based on the results of the normal co-precipitation, a simple reversed co-precipitation process has been developed.

scholarly journals Optimization of sequencing batch reactor for wastewater treatment using chemically enhanced primary treatment as a pre-treatment

Water SA ◽  
2018 ◽  
Vol 44 (3 July) ◽  
Author(s):  
Haroon R Mian ◽  
Sajjad Haydar ◽  
Ghulam Hussain ◽  
Gul -e-Hina
Keyword(s):  
Wastewater Treatment ◽  
Reaction Time ◽  
Sequencing Batch Reactor ◽  
Batch Reactor ◽  
Phase 1 ◽  
Oxygen Demand ◽  
Scale Model ◽  
Phase 2 ◽  
Removal Efficiencies ◽  
Raw Wastewater

The sequencing batch reactor (SBR) is a wastewater treatment option feasible for low flows. The objective of this research was to optimize SBR by varying its operational parameters, viz. (i) settling time and (ii) reaction time. The study was conducted in two phases. In Phase 1, raw wastewater was fed into the SBR after conventional settling, while in Phase 2 raw wastewater was fed into the SBR after coagulation-flocculation-sedimentation. A bench-scale model was set up and domestic wastewater was used for this study. Performance of the treatment system was evaluated through 5-day biochemical oxygen demand (BOD), chemical oxygen demand (COD) and total suspended solids (TSS). The results demonstrated that reaction time was reduced to 4 h in Phase 2 compared to 10 h in Phase 1. The BOD, COD and TSS removal efficiencies observed in Phase 1 were 80%, 80% and 73%, respectively, and for Phase 2 the removal efficiencies were 74%, 75% and 80% respectively. National Environmental Quality Standards (NEQS) were met in both cases and the treatment cost per cubic metre of wastewater for Phase 2 was 2.5 times lower compared to Phase 1.

Experience from 10 Years Advanced Wastewater Treatment – Technology and Results

1982 ◽  
Vol 14 (1-2) ◽  
pp. 121-133
Author(s):  
C Forsberg ◽  
B Hawerman ◽  
B Hultman
Keyword(s):  
Wastewater Treatment ◽  
Urban Population ◽  
Municipal Wastewater ◽  
Wastewater Treatment Plants ◽  
Municipal Wastewater Treatment ◽  
Treatment Technology ◽  
Removal Efficiencies ◽  
Municipal Wastewater Treatment Plants ◽  
Operational Modes ◽  
Polluted Waters

Experience from advanced municipal wastewater treatment plants and recovery of polluted waters are described for the last ten years in Sweden. Except in municipalities with large recipients, the urban population is served by treatment plants with combined biological and chemical treatment. Most of these plants are post-precipitation plants. Several modified operational modes have been developed in order to improve the removal efficiencies of pollutants and to reduce the costs. Results are presented on the recovery of specially investigated lakes with a lowered supply of total phosphorus and organic matter.

Water Pollution Abatement in Small Paper Mills in India

1988 ◽  
Vol 20 (1) ◽  
pp. 37-48 ◽  
Author(s):  
L. Panneerselvam
Keyword(s):  
Water Pollution ◽  
Wastewater Treatment ◽  
Raw Materials ◽  
Pollution Abatement ◽  
Pulp And Paper ◽  
Operating Costs ◽  
Small Scale ◽  
Pulp And Paper Mills ◽  
Paper Mills ◽  
Recovery System

In order to reduce the demand for the forest based raw materials by the organised industrial sectors like the large integrated pulp and paper mills, the Government of India started promoting several small-scale pulp and paper mills based on non-wood agricultural residue raw materials. However promotion of these small mills has created another environmental problem i.e. severe water pollution due to non-recovery of chemicals. Because of the typical characteristics like high silica content etc. of the black liquor produced and the subsequent high capital investment needed for a recovery system, it is not economically feasible for the small Indian mills to recover the chemicals. While the quantity of wastewater generated per tonne of paper produced by a small mill is same as from a large integrated pulp and paper mill with a chemical recovery system, their BOD load is four times higher, due to non recovery of chemicals. However the existing wastewater disposal standards are uniform for large and small mills for e.g. 30 mg BOD/l. To meet these standards, the small mills have to install a capital intensive wastewater treatment plant with heavy recurring operating costs. Therefore the feasible alternative is to implement various pollution abatement measures, with the objective of not only reducing the fibre/chemical loss but also to reduce the investment and operating costs of the final wastewater treatment system. To illustrate this approach, a case study on water pollution abatement and control in a 10 TPD mill, will be discussed.

Modelling the performance of anaerobic wastewater stabilization ponds

1995 ◽  
Vol 31 (12) ◽  
pp. 171-183 ◽  
Author(s):  
M. M. Saqqar ◽  
M. B. Pescod
Keyword(s):  
Wastewater Treatment ◽  
Water Temperature ◽  
Removal Efficiency ◽  
Wastewater Treatment Plant ◽  
Suspended Solids ◽  
Treatment Plant ◽  
Pond Water ◽  
Removal Efficiencies ◽  
Wastewater Stabilization Ponds ◽  
Raw Wastewater

The performance of the primary anaerobic pond at the Alsamra Wastewater Treatment Plant in Jordan was monitored over 48 months. Overall averages for the removal efficiencies of BOD5, COD and suspended solids were 53%, 53% and 74%, respectively. An improvement in removal efficiency with increase in pond water temperature was demonstrated. A model, which takes into account the variability of raw wastewater at different locations, has been developed to describe the performance of a primary anaerobic pond in terms of a settleability ratio for the raw wastewater. The model has been verified by illustrating the high correlation between actual and predicted pond performance.

scholarly journals The Variation on Sediment Reworking with Influencing Factors by a Sand Bubbler Crab, Scopimera globosa, in Intertidal Sediments of the Anmyeon Island, Korea

2021 ◽  
Vol 13 (10) ◽  
pp. 5703
Author(s):  
Jaehwan Seo ◽  
Bon Joo Koo
Keyword(s):  
Chlorophyll A ◽  
Influencing Factors ◽  
Surface Sediment ◽  
Intertidal Sediments ◽  
Daily Production ◽  
Chlorophyll A Concentration ◽  
Sediment Reworking ◽  
Pellet Production ◽  
Crab Density ◽  
Annual Sediment

Though biological and ecological characteristics of Scopimera globosa have been intensively investigated, little has been understood on bioturbation, especially sediment reworking. This study was designed to evaluate variation on sediment reworking of S. globosa based on feeding pellet production (FP) and burrowing pellet production (BP) with influencing factors and estimating the chlorophyll content reduction within the surface sediment by its feeding. The FP and BP largely fluctuated according to chlorophyll a concentration and crab density, but both were not influenced by temperature. The FP was enhanced by chlorophyll a concentration, whereas both FP and BP were restricted by crab density. The daily individual production was highest in spring, followed by fall and summer, with values of 25.61, 20.70 and 3.90 g ind.−1 d−1, respectively, while the total daily production was highest in fall, followed by summer and spring 2150, 1660 and 660 g m−2 d−1, respectively. The daily sediment reworking based on the FP and BP of Scopimera was highest in fall, followed by summer and spring, with values of 1.91, 1.70 and 0.77 mm d-1 and the annual sediment reworking rate of this species was calculated 40 cm year−1 based on its density in this study area. The chlorophyll a reduction ratio was estimated from 11 to 24% in one day by its feeding. These results imply that the sediment reworking of S. globosa is regulated by food abundance and its density, and Scopimera is an important bioturbator, greatly influencing biogeochemical changes in the intertidal sediments.

scholarly journals Chemical Removal of Cu and Zn from Swine Feces before Soil Application

Agriculture ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 377
Author(s):  
Moo-Joon Shim ◽  
Seung-Mok Lee
Keyword(s):  
Reaction Time ◽  
H2so4 Solution ◽  
Optimum Conditions ◽  
Liquid Ratio ◽  
Optimal Method ◽  
Zn Concentration ◽  
Swine Feces ◽  
Removal Efficiencies ◽  
Cu And Zn ◽  
Oxalic Acids

Cu and Zn are known to be abundant in swine feces; hence, concentrations of these metals need to be lowered before swine feces are applied to land in order to prevent potential environmental problems. The main objective of this study was to develop an appropriate chemical process to remove Cu and Zn from swine feces using acid extractions. The removal efficiencies of Cu and Zn decreased in the order of H2SO4 > HNO3 > organic acids (citric and oxalic acids). Owing to the highest removal efficiencies of Cu and Zn by using H2SO4, it was selected for further elimination of Cu and Zn from swine feces. By using H2SO4, the optimal concentration, solid-to-liquid ratio, and reaction time were 2%, 1:50, and 8 h, respectively. At the optimum conditions, Cu concentration was decreased from 198 mg/kg to 40.1 mg/kg and Zn concentration from 474 mg/kg to 80.0 mg/kg, with removal rates of 79.7% and 83.1%, respectively. The low Cu removal efficiency, resulting from the strong complexation between Cu and organic matter of swine feces, was improved by the increase in the reaction time and H2SO4 solution concentrations. However, about half of the total nitrogen (TN) was also removed by using H2SO4, indicating that the swine feces treated with H2SO4 may have poor value as fertilizer. Additional studies are required to find an optimal method to maintain TN concentrations while simultaneously removing Cu and Zn.

Sign in / Sign up

Export Citation Format

Share Document