Pilot-scale microsand-ballasted flocculation of wastewater: turbidity removal, parameters optimization, and mechanism analysis

2022 ◽  
Author(s):  
Yimin Sang ◽  
Taotao Lu ◽  
Xianchun Lu ◽  
Shuguang Wang ◽  
Xueting Shao ◽  
...  
Keyword(s):  
Pilot Scale ◽  
Parameters Optimization ◽  
Mechanism Analysis ◽  
Turbidity Removal

Pilot-Scale Microsand-Ballasted Flocculation of Wastewater: Turbidity Removal, Parameters Optimization, and Mechanism Analysis

2021 ◽  
Author(s):  
Yimin Sang ◽  
Taotao Lu ◽  
Xianchun Lu ◽  
Shuguang Wang ◽  
Xueting Shao ◽  
...  
Keyword(s):  
Process Parameters ◽  
Pilot Scale ◽  
Parameters Optimization ◽  
Optimum Dose ◽  
Mechanism Analysis ◽  
Recycled Water ◽  
Turbidity Removal ◽  
Drinking Water Standard ◽  
Jar Test ◽  
Simulated Wastewater

Abstract The flocs formed during microsand-ballasted flocculation (MBF) have attracted much attention. However, few studies have reported on comprehensive process parameters of MBF and its mechanism is still not well understood. Jar test and pilot-scale continuous experiments were here conducted on two kinds of simulated wastewater, labeled S1 (21.6-25.9 NTU) and S2 (96-105 NTU). Results revealed the hydraulic retention time ratio in the coagulation cell, injection & maturation cell, lamella settler of pilot-scale MBF equipment was 1: 3: 7.3. The optimum poly aluminum chloride doses for Samples S1 and S2 were 0.875 g/L and 1.0 g/L. Besides, the optimum size of microsand was 49-106 µm and the optimum dose was 1.0 g/L. Under aforementioned conditions, the effluent turbidity of S1 was below 0.47 NTU, lower than the Chinese drinking water standard; that of S2 was below 1.7 NTU, meeting the Chinese recycled water standard. Turbidity removal ranged from 98.0% to 98.8% for S1 and 98.5% to 99.5% for S2 when microsand was added. Therefore, microsand addition enhances MBF performance, where microsand serves as an initial core particle. Some microsand core particles bond together to form a dense core structure of micro-flocs by the adsorption bridging of inorganic polymeric flocculant. Moreover, the size of the largest micro-flocs may be controllable as long as the effective energy dissipation ɛ0 is adjusted appropriately through specific stirring speeds. This work provides comprehensive pilot-scale process parameters for using MBF to effectively treat wastewater and offers a clearer explanation of the formation mechanism of microsand-ballasted flocs.

Stormwater runoff treatment filtration system and backwashing system

2019 ◽  
Vol 79 (4) ◽  
pp. 771-778 ◽  
Author(s):  
Junho Lee ◽  
Myungjin Lee
Keyword(s):  
Particle Size ◽  
Removal Efficiency ◽  
Recovery Rate ◽  
Stormwater Runoff ◽  
Pilot Scale ◽  
Solid Loading ◽  
Filter Media ◽  
Turbidity Removal ◽  
Filtration System ◽  
Combined Sewer

Abstract This study has been carried out to evaluate the applicability of the pilot scale hybrid type of stormwater runoff treatment system for treatment of combined sewer overflow. Also, to determine the optimum operation parameter such as coagulation dosage concentration, effectiveness of coagulant usage, surface loading rate and backwashing conditions. The pilot scale stormwater filtration system (SFS) was installed at the municipal wastewater plant serving the city of Cheongju (CWTP), Korea. CWTP has a capacity of 280,000 m3/day. The SFS consists of a hydrocyclone coagulation/flocculation with polyaluminium chloride silicate (PACS) and an upflow filter to treat combined sewer overflows. There are two modes (without PACS use and with PACS use) of operation for the SFS. In case of no coagulant use, the range of suspended solids (SS) and turbidity removal efficiency were 72.0–86.6% (mean 80.0%) and 30.9–71.1% (mean 49.3%), respectively. And, the recovery rate of filter was 79.2–83.6% (mean 81.2%); the rate of remaining solid loading in filter media was 16.4–20.8% (mean 18.8%) after backwashing. The influent turbidity, SS concentrations were 59.0–90.7 NTU (mean 72.0 NTU), 194.0–320.0mg/L (mean 246.7mg/L), respectively. The range of PACS dosage concentration was 6.0–7.1mg/L (mean 6.7mg/L). The range of SS and turbidity removal efficiency was 84.9–98.2 (mean 91.4%) and 70.7–96.3 (mean 84.0%), respectively. It was found that removal efficiency was enhanced with PACS dosage. The recovery rate of filter was 92.0–92.5% (mean 92.3%) the rate of remaining solid loading in filter media was 6.1–8.2% (mean 7.2%) after backwashing. In the case of coagulant use, the particle size of the effluent is bigger than influent particle size. The results showed that SFS with PACS use more effective than without PACS use in SS and turbidity removal efficiency and recovery rate of filter.

scholarly journals Turbidity removal by rapid sand filter using anthracite coal as capping media

2021 ◽  
Vol 4 (1) ◽  
pp. 69-73
Author(s):  
Gopal Tamakhu ◽  
Iswar Man Amatya
Keyword(s):  
Comparative Analysis ◽  
Water Treatment ◽  
Bituminous Coal ◽  
Pilot Scale ◽  
Sand Filters ◽  
Turbidity Removal ◽  
Sand Filter ◽  
Filter Materials ◽  
Water Treatment Plants ◽  
Anthracite Coal

Rapid sand filters are very common in all conventional water treatment plants. Capping of existing rapid sand filters can be the promising method of improving the performance of rapid sand filters. Capping is process in which upper sand bed layer of few cm is replaced with capping material. However, this technique is limited in India due to unavailability of filter materials apart from sand. Some materials suitable for capping are anthracite coal, PVC granules, bituminous coal, broken bricks, etc. The attempt is made to study the effect of capping of Rapid sand filters by the use of anthracite coal as a capping media by pilot scale study. A series of test runs and experiments using different influent turbidity were tried. The pilot scale study has shown very encouraging results. Comparative analysis shows that higher rate of filtration is possible along with higher filter run and less backwash requirement. In the present work, conventional rapid sand filter and capped rapid sand filter are compared.

Competitive mechanism of ammonia, iron and manganese for dissolved oxygen using pilot-scale biofilter at different dissolved oxygen concentrations

2015 ◽  
Vol 16 (3) ◽  
pp. 766-774 ◽  
Author(s):  
Qingfeng Cheng
Keyword(s):  
Dissolved Oxygen ◽  
Pilot Scale ◽  
Turbidity Removal ◽  
Manganese Removal ◽  
Start Up ◽  
Competitive Mechanism ◽  
Iron And Manganese ◽  
Oxygen Concentrations

In this study, the competitive mechanism of ammonia, iron and manganese for dissolved oxygen (DO) in a biofilter was investigated, and a new start-up method of a biofilter for ammonia, iron and manganese removal was approved, which can effectively shorten the start-up period from 3–4 months to 51 days. The results demonstrated that when DO was sufficient (about 8 mg · L−1), ammonia, iron and manganese could be completely removed. When DO decreased from 6.5 to 4 mg · L−1, the concentration of ammonia in the effluent increased accordingly, though iron and manganese were removed efficiently. When DO was as low as 3 mg · L−1, only iron was removed, whereas most of the ammonia and manganese still existed in the effluent. In addition, the oxidizing rates of the pollutants were not affected significantly with DO decrease. Turbidity removal in the biofilter was also investigated, and the results demonstrated that the turbidity decreased to less than 0.5 NTU at 0.4 m depth of the filter.

Influence of Backwashing Time on Iron, Manganese, Ammonia and Turbidity Removal Using a Pilot-Scale Biological Filter

2013 ◽  
Vol 807-809 ◽  
pp. 1097-1102
Author(s):  
Qing Feng Cheng ◽  
Dong Li ◽  
Xiang Kun Li ◽  
Ling Wei Meng ◽  
Jie Zhang
Keyword(s):  
Removal Efficiency ◽  
Pilot Scale ◽  
Average Concentration ◽  
Total Iron ◽  
Operational Parameters ◽  
Turbidity Removal ◽  
Biological Filter ◽  
The Media ◽  
Iron Manganese

Backwashing time is one of the most critical operational parameters for biological filter. In order to investigate the effect of backwashing time on iron, manganese, ammonia and turbidity removal, three backwashing time (5 min, 4 min and 3 min) were adopted. Results showed that the average concentration of total iron, manganese and ammonia in effluent was 0.025 mg/L, 0.007 mg/L, and 0.022 mg/L; 0.012 mg/L, 0.001 mg/L and 0.017 mg/L; 0.013 mg/L, 0.000 mg/L and 0.016 mg/L, respectively, which illustrated varying backwashing time had little influence on the removal efficiency of them. The turbidity in effluent was 0.28 NTU, 0.38 NTU, 0.57 NTU, respectively. The shorter backwashing time, the higher turbidity in effluent. Turbidity was almost completely removed in 0~0.4m of the media. After backwashing, the turbidity in effluent was decreased to less than 1 NTU in 40 min, droped to less than 0.5 NTU in 90 min.

Comparison on Permanganate and Ozone as Pre-Oxidation Agents

2014 ◽  
Vol 955-959 ◽  
pp. 3408-3413 ◽  
Author(s):  
Hong Wei Sun
Keyword(s):  
Drinking Water ◽  
Treatment Process ◽  
Removal Rate ◽  
Oxygen Demand ◽  
Drinking Water Treatment ◽  
Pilot Scale ◽  
Turbidity Removal ◽  
Trihalomethane Formation Potential ◽  
Water Treatment Process ◽  
Oxidation Reactor

Comparative study on permanganate and ozone as pre-oxidation agents were performed on pilot scale with traditional drinking water treatment process, chemical oxygen demand (COD), total organic carbon (TOC), UV254, turbidity, trihalomethane formation potential (THMFP) were examined at each reactor’s effluent. The results show that at pre-oxidation reactor, the total organic remained stable after by the two agents, while for UV254, pre-ozonation has a removal rate of 34%, comparing that of 17% by permanganate. At the sedimentation process, 0.4 mg/L permanganate improves the removal rate of turbidity and COD by 0.99 % and 8.4%, respectively; while a positive COD removal of 11.8 % was achieved by 0.9 mg/L pre-ozonation, and an average of-10.08% turbidity removal was achieved at applied dosage (0.5, 0,9 and 1.5 mg/L), which can be made up for in the followed sand filtration reactor. Both permanganate and pre-ozonation show higher removal rate of THMFP for the finished water.

Impact of operational parameters on biofiltration performance: organic carbon removal and effluent turbidity

2016 ◽  
Vol 16 (6) ◽  
pp. 1683-1692 ◽  
Author(s):  
Vivek A. Nemani ◽  
Lizbeth Taylor-Edmonds ◽  
Nicolas M. Peleato ◽  
Robert C. Andrews
Keyword(s):  
Energy Consumption ◽  
Surface Water ◽  
Organic Carbon ◽  
Dissolved Organic Carbon ◽  
Contact Time ◽  
Lake Ontario ◽  
Pilot Scale ◽  
Operational Parameters ◽  
Turbidity Removal ◽  
The Impact

The objectives of this pilot-scale study were to optimize backwash frequency and empty bed contact time (EBCT) of biofilters treating ozonated surface water from Lake Ontario. Performance was benchmarked in terms of the reduction of turbidity, dissolved organic carbon (DOC), disinfection by-product (DBP) precursors, and ultrafiltration foulants (biopolymers). Increasing the EBCT from 4 to 8 min resulted in a higher reduction of DOC (5%), trihalomethane (THM4) and haloacetic acid (HAA9) precursors (∼12%) without negatively impacting effluent turbidity (consistently below 0.4 NTU), while biopolymer removal remained unaffected (2%). The impact of varying backwash frequency (5, 10, and 25 day intervals) was also compared for biofilters operated at an EBCT of 4 min. Results showed no impact of extended run times (up to 25 days) on DOC or DBP precursor removal; however turbidity removal was affected beyond 15 days of operation. Backwashing biofilters at 10 vs 5 day intervals would result in a reduction of backwash water, energy consumption and amount to nearly $17,000 in savings for the utility.

Biofilter pretreatment for the control of microfiltration membrane fouling

2002 ◽  
Vol 2 (2) ◽  
pp. 193-199 ◽  
Author(s):  
J. Park ◽  
S. Takizawa ◽  
H. Katayama ◽  
S. Ohgaki
Keyword(s):  
Membrane Fouling ◽  
Metal Removal ◽  
Removal Rate ◽  
Experimental Period ◽  
Pilot Scale ◽  
Major Effect ◽  
Water Turbidity ◽  
Turbidity Removal ◽  
Time Variations ◽  
Fouling Reduction

A pilot scale biofilter pretreatment - microfiltration system (BF-MF) was operated to investigate the effect of biofilter treatment in fouling reduction of microfiltration. Biofiltration was expected to reduce the membrane fouling by removal of turbidity and metal oxides. The hollow-fiber MF module with a nominal pore size of 0.1 μm and a surface area of 8m2 was submerged in a filtration tank and microfiltration was operated at a constant flux of 0.5 m/d. Biofiltration using polypropylene pellets was performed at a high filtration velocity of 320 m/d. Two experimental setups composed of MF and BF/MF, i.e. without and with biofilter pretreatment, were compared. Throughout the experimental period of 9 months, biofilter pretreatment was effective to reduce the membrane fouling, which was proved by the result of time variations of trans-membrane pressure and backwash conditions. The turbidity removal rate by biofiltration varied between 40% to 80% due to the periodic washing for biofilter contactor and raw water turbidity. In addition to turbidity, metals, especially Mn, Fe and Al were removed effectively with average removal rates of 89.2%, 67.8% and 64.9%, respectively. Further analysis of foulants on the used membranes revealed that turbidity and metal removal by biofiltration was the major effect of biofiltration pretreatment against microfiltration fouling.

Pilot-scale fluoride-containing wastewater treatment by the ballasted flocculation process

2013 ◽  
Vol 68 (1) ◽  
pp. 134-143 ◽  
Author(s):  
Bin-yuan Wang ◽  
Zhong-lin Chen ◽  
Jia Zhu ◽  
Ji-min Shen ◽  
Ying Han
Keyword(s):  
Calcium Fluoride ◽  
Fluoride Concentration ◽  
Pilot Scale ◽  
Fluoride Removal ◽  
Turbidity Removal ◽  
Factors Affecting ◽  
Flocculation Efficiency ◽  
Sludge Recycling ◽  
Efficiency Factors ◽  
Flocculation Process

A pilot-scale ballasted flocculation system was used to remove fluoride from one type of industrial wastewater. The system included the formation of calcium fluoride (CaF2) using calcium hydroxide followed by coagulation sedimentation. Calcium fluoride was recycled as nuclei for enhancing CaF2 precipitation and as a ballasting agent for improving fluoride removal and flocculation efficiency. Factors affecting fluoride and turbidity removal efficiencies, including pH in the CaF2-reacting tank and coagulation-mixing tank, sludge recycling ratio, and dosages of FeCl3 and polyacrylamide (PAM), were investigated in the pilot-scale system. The recycled CaF2 precipitates improved CaF2 formation kinetics, enhanced fluoride removal and flocculation performance. Under the optimized condition, the ballast flocculation process reduced fluoride concentration from 288.9 to 10.67 mg/L and the turbidity from 129.6 NTU to below 2.5 NTU.

Sign in / Sign up

Export Citation Format

Share Document