Removal Efficiency Of Suspended Solids Research Articles

Effect of Cone-Plate Clarifier Structure Parameters on Flocculation Efficiency

In this study, a coal mine water flocculation system was established. A series of flocculation tests were carried out at different structural parameters (cylinder height, cone-plate insertion depth and cone-plate spacing) to better investigate the effect of the cone-plate clarifier on coal mine water treatment performance. Sixteen sampling points were set up in the system for data monitoring to generate the required data. The cone-plate clarifier was divided into five zones for flocculation analysis. The increased cylinder height facilitated the flocculation of particles in the micro flocculation zone and the settling of particles in the settlement zone. The chemicals used are polyaluminum chloride (PACl), Fe3O4 and polyacrylamide (PAM), corresponding to doses of 60 mg/L, 40 mg/L and 6 mg/L, respectively. Insufficient insertion depth of the cone-plate will cause the small flocs that have not been fully flocculated to enter the exit pipe zone directly through the cone-plate, while too much insertion depth will cause the large floc in the settlement zone to re-enter the exit pipe zone. The flocculation effect of small flocs increased as the cone-plate spacing decreased, which is consistent with the shallow pool theory. When the cone plate spacing was too narrow, the amount of fluid was reduced and the increase in fluid velocity reduced the flocculation effect. Curve fitting was conducted for Suspended solids(SS) and turbidity removal efficiency under each structural parameter to derive the variation of SS and turbidity removal efficiency under different structural parameters. The regression models of SS and turbidity removal efficiency on the cylinder height, cone-plate insertion depth and cone-plate spacing were established based on the curve fitting results, and the regression models were verified to be well fitted based on the comparison of experimental results. Finally, the optimal values of SS and turbidity removal efficiency were found based on the regression model. The flow rate of the cone-plate clarifier is 0.6 m3/h. The SS removal efficiency reached 96.82% when the cylinder height was 708 mm, the cone-plate insertion depth was 367 mm and the cone-plate spacing was 26 mm. The turbidity removal efficiency reached 86.75% when the cylinder height was 709 mm, the cone-plate insertion depth was 369 mm and the cone-plate spacing was 26 mm.

Optimisation of operating conditions during coagulation-flocculation process in industrial wastewater treatment using Hylocereus undatus foliage through response surface methodology.

In exploring the application of natural coagulants in industrial wastewater treatment, plant-based coagulants have been gaining more interests due to their potential such as biodegradability and easy availability. Hylocereus undatus foliage as a plant-based coagulant has been proven to be efficient during the coagulation-flocculation process; however, limited research has been reported focusing only on palm oil mill effluent (POME) and latex concentrate wastewater. In addition, no previous study has been carried out to determine the performance evaluation of Hylocereus undatus foliage in treating different types of wastewater incorporating different operating conditions using optimization techniques. Hence, this study employed response surface methodology (RSM) in an attempt to determine the performance evaluation of the coagulant in paint wastewater treatment. Four independent factors such as the pH value, coagulant dosage, rapid mixing speed and temperature were chosen as the operating conditions. Three water parameters such as turbidity, chemical oxygen demand (COD) and suspended solids (SS) were chosen as responses in this study. Results revealed that through central composite design (CCD) via Design Expert software, the optimum conditions were achieved at pH 5, coagulant dosage of 300mg/L, rapid mixing speed of 120rpm and temperature at 30°C. The experimental data was observed to be close to the model predictions with the optimum turbidity, COD and SS removal efficiencies found to be at 62.81%, 59.57% and 57.23%, respectively.

Forecasting effluent and performance of wastewater treatment plant using different machine learning techniques

Expectation of wastewater quality in wastewater treatment plants (WWTPs) is significant and can decrease the sampling number, cost, decision time, and energy. This paper presents two methods for predicting and forecasting the removal efficiency of total suspended solids (TSS), chemical oxygen demand (COD), biological oxygen demand (BOD5), ammonia, and sulphide at El-Berka wastewater treatment plant, Egypt. The first method uses different prediction models, includes the use of traditional feed-forward (TF), deep feed-forward backpropagation (DFB), and deep cascade-forward backpropagation (DCB) networks. The TF was generated in three layers: input, hidden, and an output layer. The DFB network comprised of six layers: an input, four hidden, and an output layer. The DCB network was created with six layers (with skip connections): an input, four hidden, and an output layer. The other method is a forecasting model by using deep learning time series forecasting (DLTSF) with a long short-term memory (LSTM) network. The developed models were trained, validated, and tested on a real-life dataset over eight years. The results indicated that the presented models could effectively predict and forecast the future series values of the removal efficiency of the El-Berka WWTP. The DCB network achieved the highest accuracy as compared to those exhibited by the TF and DFB networks. The RMSE and R-squared for training with the DCB model are 1.95 and 0.90, respectively. The RMSE of DLTSF was 0.85 for forecasting of BOD5. Thus, the DCB and DLTSF models are recommended for evaluating and predicting the performance of WWTP.

Removal and Survival of Fecal Indicators in a Constructed Wetland after UASB Pre-Treatment

The experimentation plant, based on a sub-surface horizontal flow phytodepuration (SSHFP) unit with a pre-treatment by an upflow anaerobic sludge blanket (UASB) reactor, proved valuable in treating the sewage of a small rural community located in north Brazil. During a six-month trial, the plant achieved an average removal efficiency of 98.2% (1.74 log removal) for fecal coliforms (FC) and 96.0% (1.40 log removal) for Enterococci (EN), as well as 95.6% for BOD5, 91.0% for COD,00 and 95.4% for suspended solids (SS). The contribution of the UASB reactor to this overall performance was very significant as, alone, it achieved a yield of 62.7% for FC and 60% for EN, in addition to 65.2% for BOD5 and 65.0% for SS. EN was chosen, in addition to FC, because of its higher specificity and strong environmental persistence, leading to an increased risk to human health. In fact, the experimental results confirmed its lower removal efficiency compared to FC. The mechanical and biological mechanisms that led to such a removal efficiency of the two fecal indicators (FIs) are outlined in the article. The same mechanisms led to a good level of equivalence between the removal efficiency of the two FIs with the removal efficiency of SS and BOD5, for both the whole plant and the UASB reactor alone. The research demonstrated the close correlation between the concentrations of EN and FC for the plant effluent. This correlation can be explained by the following mathematical expression of the regression line Log EN = 0.2571 Log FC + 3.5301, with a coefficient of determination R2 = 0.912. This implies that the concentration of the more specific indicator EN could be calculated, with acceptable approximation, from the simple analysis of FC and vice versa. The experimental plant brought important health benefits to the local population. In particular, there were no significant odor emissions; moreover, the risk of fecal pathogenic diseases was drastically reduced; finally, there was no proliferation of insects and other disease vectors, due to the absence of stagnant or semi-stagnant water exposed to the atmosphere.

Hydraulic characteristics of integrated settler based biofilm reactor as onsite sanitation system

Abstract The present study identifies the hydraulic efficiency of a novel onsite sanitation system at variable hydraulic shock loading conditions. The system consisted of three chambers, each working as an up-flow anaerobic bioreactor, accommodated within a single unit. The hydraulic characteristics were identified with the help of residence time distribution (RTD) analysis by step feeding of lithium chloride (LiCl) solution into the system. The experiments were run at variable hydraulic loading conditions at different peak flow factors (PFF) of 1, 2, 4 and 6 while maintaining 24-h hydraulic retention time. As revealed in the RTD analysis, the biofilm reactor achieved a very good hydraulic efficiency that varied from 0.76 to 0.81 at PFF 1, 2 and 4. Although in the case of PFF6, it was comparatively low. It was noted that the dispersion number was always below 0.2 at variable hydraulic shock loading conditions under different PFFs, which indicated that the reactor behaved perfectly between mixed-flow and plug-flow reactor. The system was also able to achieve good pollutant removal efficiency for chemical oxygen demand (COD) and total suspended solids (TSS) under all PFFs, which was more than 68 and 75%, respectively.

Improving the quality of stabilization pond effluents using hybrid constructed wetlands

Water shortage and excessive use of water resources in arid and semi-arid regions, such as Iran, highlights the importance of using treated wastewater, especially for the highly demanding agricultural sector. Constructed wetlands (CWs) are among green technologies that offer an efficient and cost-effective wastewater treatment. This study investigates the complementary treatment of effluent from the Fooladshahr wastewater treatment plant, Isfahan, Iran, using pilot-scale CWs with horizontal (H-CW) and horizontal-vertical flow (HV-CW). The performance of two substrates, pumice and gravel, and the effect of using plants (Phragmites australis) was compared. Maximum removal efficiencies of total suspended solids (TSS) and biochemical oxygen demand (BOD5) were observed in the case of unplanted and planted HV-CW with pumice bed, respectively. In the case of gravel bed, planted H-CWs demonstrated maximum chemical oxygen demand (COD) removal efficiency. The highest mean outflow concentrations for TSS, BOD5 and COD were obtained in unplanted H-CW with pumice bed, likely due to shorter retention times compared to HV-CWs, as well as due to the absence of plants providing the required physicochemical and biological conditions for high performance treatment. Phosphate (PO43−) removal efficiency demonstrated seasonal dependency, where the highest values were obtained in warm seasons. In the case of fecal coliforms (FC), no significant differences were observed between the studied HV-CWs during the whole study period. Based on our results, planted H-CW with gravel bed provided an optimum removal efficiency while requiring a smaller footprint and lower expenditure than HV-CWs. This study demonstrates the application of CWs as an affordable solution for treating domestic wastewater for various reuse application in developing countries with water crisis, such as Iran.

Enhancing the biogas production and the treated effluent quality via an alternative Palm Oil Mill Effluent (POME) treatment process: Integration of thermal pretreatment and dewatering

To address the limitations associated with the disposal management and the treatment process of POME, an alternative process that consists of eliminating the cooling ponds and integrating a pretreatment technology combined with a dewatering device was proposed. Since the proposed treatment process has not been tested previously, the objective of this study is to investigate the effect of thermal pretreatment and solid loading alteration via dewatering on a thermophilic continuous set up consisting of an upflow anaerobic sludge blanket – hollow centered packed bed (UASB-HCPB) bioreactor. It was established that the best performing solid loading was the 40S:60L, which is made up of 40% by volume of POME settled solids and 60% of clarified liquid. Thermally pretreated 40S:60L solid loading had a significantly enhanced biogas production, methane purity, chemical oxygen demand (COD), biological oxygen demand (BOD), and total suspended solids (TSS) removal efficiencies. The reactor exhibited stability owing to the low volatile fatty acid/alkalinity ratio obtained throughout the run. With a reactor capacity of 5L, thermally pretreated 40S:60L achieved a daily biogas production volume of 48L and a methane purity of 77.2%. The COD, BOD, and TSS removal efficiencies of the thermally pretreated 40S:60L solid loading were evaluated to be 97.5, 95.1, and 94.5%. The enhanced process performance is due to the consistent solids concentration, which allowed a more effective mass transfer and transport in the medium. Meanwhile, thermal pretreatment promoted cell lysis, making the intercellular organic matter readily available for the bacteria consortium.

Improving the performance of vertical flow constructed wetlands by modifying the filtering media structure.

The aim of this research was to study the influence of the bed media configuration and particle size on the treatment efficiency of subsurface vertical flow (VF) constructed wetlands (CWs) treating municipal wastewater. Two outdoor pilot units (VF1 and VF2, planted with Phragmites australis) with the configuration C1 were operated in parallel for 2 years at similar surface loading rates of 9.7 ± 3.2 (VF1) and 10.1 ± 3.3 (VF2) g biological oxygen demand (BOD5)/m2·day (19.5 ± 6.4 (VF1) and 20.4 ± 6.2 (VF2) g chemical oxygen demand (COD)/m2·day). A different configuration C2 was used during the third year at 16.9 ± 4.6 (VF1) and 18.2 ± 3.0 (VF2) g BOD5/m2·day and 26.0 ± 7.2 (VF1) and 28.0 ± 4.7 (VF2) g COD/m2·day. Two different filtering materials (1-3-mm sand for VF1 and 2-6-mm fine gravel for VF2) were used for configuration C1. The same units were modified after 2 years of operation by adding a 10-cm layer of fine sand (0-2 mm) on the top (configuration C2). In C1 conditions, the unit with the coarse material VF2 showed significantly (p < 0.05) lower removal efficiencies of total suspended solids (TSS) and BOD5 than VF1, and both units failed to meet the BOD5 discharge limit. In C2 conditions, removal efficiencies reached 82% TSS, 97% BOD5, 76-81% ammonia, and 60-66% TN, without significant differences between VF1 and VF2 units. Removal efficiencies were significantly higher for configuration C2 than that for C1, due to the positive effect of the upper fine sand layer. The presence of this fine sand layer doubled the water retention time and increased the removal rates, while the infiltration rates were high enough for an operation free of clogging.

Performance application of ultraviolet disinfection technique for raw water

Microbial water disinfection with UV rays is a universal technology. Disinfection is a method used to treat drinking water. This can be accomplished using physical and/or chemical processes. Physical Methods: Heating and UV rays are two main methods - UV rays to destroy cells and kill bacteria. The physical process generally gives drinking water an instant purification without producing harmful substances. However, there is no pollution in the water to ensure continuous cleaning. This study’s primary goal is to obtain environmentally safe drinking water in situations of water shortages and homes that lack clean water. Therefore, resort to appropriate home treatment. Therefore, an experimental laboratory has been established to test the ceramic filter’s efficiency in removing turbidity and plankton and everything that would change the properties of drinking water. Thus, several stages in water purification are shortened, as in the case of water treatment plants. To determine the efficiency of UV sterilization in killing bacteria, especially fecal coliform bacteria and E-coli bacteria. Work has taken place by taking samples of river water near Al Wahda water treatment plant. This technique works on water according to special criteria before entering the sterilizer. A commercially available ceramic filter was used for this. The ceramic filter is excellent at reducing turbidity with removal efficiency (96 ∼ 97%), suspended solids removal efficiency (99 ∼ 100%), iron removal efficiency (100%), bacteria removal efficiency (45 ∼ 50 %) which is good removal rate because it is a commercial filter. The efficiency of the UV sterilizer in killing bacteria reached (100%). This technique is very excellent as it does not produce secondary substances and does not change color, taste, or smell.

Optimization of continuous electrocoagulation-adsorption combined process for the treatment of a textile effluent

Experimental setup: (a): Real schematic of pilot, (b): 3D scheme of pilot/ 1: tank with untreated effluent, 2: variable frequency pump, 3: Electrocoagulation reactor, 4: adsorption reactor, 5: mechanical stirrer, 6: tank for sedimentation, 7: acrylic container of the suspension of clay, 8: mechanical mixer of the suspension of clay, 9: 12 Volt peristaltic pump, 10: control panel of current supplier, 11: 10 parallel iron electrodes. • The full continuous combined process based on electrocoagulaion-adsorption on crude clay is a very efficient process for textile effluent decontamination. • The achieved removal efficiencies of color, COD and TSS were respectively 96.87%, 89.77% and 84.46%. • The achieved treated effluent fulfill the Tunisian standards of rejected wastewater and could be used in preparation process or in irrigation. • Treatment efficiencies were enhanced at neutral pH range, slow effluent flow rate, high voltage and high adsorbent suspension flow rate. The aims of this study is to design and optimize the functioning of a full continuous combined process based on electrocoagulaion-adsorption on crude Tunisian clay to treat a real textile effluent. The clay characterization shows that the used clay is a rich-smectite clay. The response surface methodology (RSM) technique based on Box-Behnken design (BBD) was used to optimize the process. At optimum conditions which are initial pH solution of 8.24, effluent flow rate of 0.5 L·min −1 , voltage of 70 V, and added suspension of clay flow rate of 100 ml·min −1 the achieved color, chemical oxygen demand (COD) and total suspended solid (TSS) removal efficiencies were respectively 96.87%, 89.77% and 84.46% with 0.75USD·m −3 as total cost. The additional laboratory experiments at optimum conditions agree with the predicted results, which confirm the accuracy and the capability of RSM to predict results in the defined space. Finally the designed process could be a good eco-friendly alternative to treat and reuse wastewater in industrial process with reasonable cost.

Electrochemical mineralization of abattoir wastewater with continuous system

This study aims to determine the effects of initial pollutant concentration level (1/1–1/4), flow rate (10–40 mL/min), NaCl concentration (0.1–1 M), pH (3–9) and current density (4.73–23.67 mA/cm2) parameters on the removals of total suspended solids, total organic carbon, chemical oxygen demand, total nitrogen and color for economic treatment of cattle-abattoir wastewater using mesh-type Ti/Pt anodes with continuous EO system. Total suspended solids, total organic carbon, chemical oxygen demand, total nitrogen and color analyses were carried out according to photometric method, catalytic oxidation method, closed reflux colorimetric method, nitrogen cell test method and platinum–cobalt method, respectively. The effluent chloride levels were analyzed according to the argentometric titration method. According to results, all operational parameters had an impact on removal efficiencies but the most effective parameters on energy consumption were NaCl concentration and applied current density. Although two possible system conditions were determined according to removal efficiencies the operating conditions with the lowest energy consumption are considered to be optimal. The optimum operating conditions were determined as NaCl concentration of 1 M, CD of 4.73 mA/cm2, initial pH of 7.03, reaction temperature of 25 °C and FR of 10 mL/min. Under these conditions removal efficiencies (%) for total suspended solids, total organic carbon, chemical oxygen demand, total nitrogen and color were found as; 98.28, 93.03, 97.44, 95.53 and 99.80, respectively. The energy consumption values were calculated as 2.42 kWh/kg COD and 19.43 kWh/m3. The approximate cost to treat 1 m3 wastewater was calculated as $ 6.43. The kinetic behavior abided by a pseudo-first-order model.

Efficient Treatment of Domestic Wastewaters by Using a Dynamic Membrane Bioreactor System

Membrane bioreactor (MBRs) technology is a crucial treatment process having enhanced solid/liquid separation in the way of biological wastewater treatment. However, clogging problem in MBRs is a critical drawback. Dynamic membrane (DM) technology has recently taking more attention to eliminate the clogging problem. DM is known as a self-forming cake layer on a support layer determining the rejection properties of the system. Recently, there is a great concern and more research need to understand and model the complex structure of DM and find proper support material. This study focused on the development of an efficient DM system with different textile fabric support materials in order to treat domestic wastewater. The applicability of two textile fabrics as cotton textile fabric (TF) and metal braided one (MBTF) as support layers with ultrafiltration membrane (UF) were investigated based on the chemical oxygen demand (COD), suspended solids (SS), specific resistance to filtration (SRF), and cake depth parameters. COD and SS removal efficiencies showed that TF support layer provided better reductions.

Characterization of pistachio processing industry wastewater and investigation of chemical pretreatment

This study was carried out in two stages; in the first stage of the study, wastewater characterization of wastewater originating from the pistachio industry was primarily completed, and in the second stage, chemical pre-treatment studies were completed. Pistachio wastewater used in the study was obtained from a pistachio processing factory located in Gaziantep province. In chemical treatment studies, montmorillonite clay, AlCl3, Al2(SO4)3, Fe2(SO4)3 and FeCl3 were used as coagulants. As a result of chemical treatability tests, AlCl3 was determined to be the best coagulant. With AlCl3 at optimum dosage and optimum pH value, 99.6% suspended solid (SS) removal efficiency, 65.8% chemical oxygen demand (COD) removal efficiency and 85.5% total phenol (TP) removal efficiency were obtained.

The impact of seasonal variations about temperature and photoperiod on the treatment of municipal wastewater by algae-bacteria system in lab-scale

The co-cultivation of microalgae and bacteria has become an attractive approach for treating wastewater. This approach can achieve both cost-effective nutrient removal and biomass resource recovery. However, the development of full-scale algae-bacteria systems or enhanced pond systems has been limited, because of the complexity and changeability of environmental factors in this process. This study investigated the effects of seasonal variations about temperature and photoperiod on municipal wastewater treatment by algae-bacteria system in lab-scale. Nutrient removal, biomass growth, settling ability, and community structures were examined using cultures of Chlorella vulgaris, Scenedesmus obliquus, Spirulina platensis, and aerobic activated sludge in raw municipal wastewater. Results showed that the nutrient removal and biomass yield varied with seasonal conditions. High removal rates and biomass production percentages were achieved in summer and autumn conditions with aeration. The highest specific growth rate was 0.46 d−1; the highest total nitrogen removal rate was 2.34 d−1; and the highest total suspended solids removal efficiency was 96.3 ± 2.1% in summer conditions with aeration. The highest total phosphorus removal rate was 1.67 d−1 in the autumn season with aeration. An overall analysis indicated that Chlorella vulgaris and Scenedesmus obliquus, combined with bacteria (Proteobacteria, Firmicutes, Bacteroidetes, Chloroflexi) can effectively use different carbon, nitrogen, and phosphorus sources from wastewater in summer and autumn conditions. Further research should focus on methods for effectively and inexpensively improving nutrient removal and recovering biomass at low temperatures and with short photoperiods.

Green sustainable technology for biotreatment of actual dairy wastewater in constructed wetland

AbstractBACKGROUNDDue to the environmental problems caused by food processing wastewaters and their complex and expensive treatment methods, it becomes mandatory to seek a sound, sustainable and environmentally friendly solution such as constructed wetland (CW). This study aimed to investigate the potential of treating real dairy wastewater in CW. Six horizontal subsurface flow CW microcosms were set up using different conventional and cost‐effective supporting media, which were gravel, soil and sand. All the CWs were fueled continuously with real fresh dairy wastewater. Five of the six CW microcosms were planted with Canna indica. The remaining CW microcosm was kept unplanted and was considered as a control microcosm.RESULTSThe results revealed significant removal efficiencies of organic matter (as chemical oxygen demand) up to 89.92%, 97.6%, 95.8%, 97.2%, 97.3% and 98.2%, for CW1, CW2, CW3, CW4, CW5 and CW6, respectively. Also, high removal efficiencies of ammonium were observed in the range of 98.4–82.0%, whereas removal efficiencies of total suspended solids were in the range of 99.2–93.4%.CONCLUSIONThe results demonstrated that the dominant mechanisms for organics and ammonium removal were biodegradation processes. These promising results confirmed the validity of using constructed wetland as a sustainable cost‐effective approach for dairy wastewater treatment. © 2020 Society of Chemical Industry

Co-pretreatment of Municipal Wastewater and Landfill Leachate by Chemical Coagulation Using Ferric Chloride and Aluminum Sulfate

In this study, co-pretreatment of municipal wastewater (MW) and landfill leachate (LL) was investigated by means of coagulation using ferric chloride and aluminum sulfate. The effects of operating conditions on process performance were examined, which included pH, coagulant type and coagulant dose. For both coagulants, the best removal efficiency was achieved at the initial pH of 5. At this pH, the removal efficiencies of chemical oxygen demand (COD), suspended solids (SS) and turbidity were 82%, %99 and %99, respectively with ferric chloride and 72%, 98% and 98.5%, respectively with aluminum sulfate. For the ratios ranging between 10:1 and 5:1 of MW to LL, the optimum dose was determined as 500 mg/L for both coagulants. When the ratio of MW to LL was reduced from 5:1 to 1:1, the coagulant dose required was raised from 500 to 1000 mg/L and the removal efficiency of pollutants reduced. Better removal efficiencies were achieved by ferric chloride in comparison to aluminum sulfate. The results revealed that coagulation could be applied as pretreatment for co-treatment of MW and LL.

Partitioning of Mercury into Several Size Fractions in Highway Runoff

Due to their large impervious coverage, highways are ideal sites for the transport of pollutants to either treatment units or direct discharge to waterways. Mercury, a highly toxic and ubiquitous environmental contaminant, is rarely studied in stormwater runoff. Removal of particulate-bound mercury in a dry detention basin was analyzed for the five size fractions: <0.45 μm, 0.45–8 μm, 8–20 μm, 20–100 μm, and >100 μm. The highest concentration of mercury for both influent and effluent is observed in the 8–20 μm size fraction. Treatment units are often characterized by suspended solids removal efficiency and particle-bound pollutants correlated to suspended solids removal; however, different suspended solids removal efficiency may occur in specific particle size fractions. Therefore, the benefits of treatment units may be different than originally anticipated, especially if the particle-bound concentrations are greater in fractions more efficiently removed. For sedimentation-based treatment units, the removal is dependent on size fraction, and when one size fraction is captured more efficiently, the removal rate calculated using the entire sample might indicate particle-bound pollutant removal quite different than actually occurring.

Combined dual-size foam glass media filtration process with micro-flocculation for simultaneous removal of particulate and dissolved contaminants in urban road runoff

In this study, a combined media filtration process with micro-flocculation (CMF) was developed, to simultaneously treat particulate and dissolved contaminants in urban road runoff. Dual-size foam glass media with stone and sand layers were applied and the efficiency of road runoff treatment was investigated according to filtration and micro-flocculation under various experimental conditions (stone/sand layer ratio, linear velocity, and coagulant types). Moreover, the removal efficiencies of suspended solids (SS), phosphorus, organic carbon, and heavy metals (Zn, Cu, Pb, Cd) by CMF were evaluated. The removal rate of SS was maintained to be above 84.1% for 1 h filtration by the dual-size foam glass, regardless of increasing pressure. The removal of phosphorus by micro-flocculation was more suitable in alum than ferric due to a higher initial floc growth rate and an increased particle size. The performance of the CMF was significantly improved over media filtration only process (MF) in removing both particulate and dissolved contaminants. The removal efficiency of all particulate pollutants by CMF was found to be more than 90%, and notably, the dissolved phosphorus, which was mostly not removed by MF, was also removed by 97.4%. Meanwhile, the backwash efficiency of CMF was half that of MF. Physical removal mechanisms, such as internal diffusion, dominated MF, whereas chemical removal mechanisms, such as adsorption and surface precipitation, dominated CMF. These results show the potential of the CMF process for the treatment of urban road runoff and identify the removal mechanisms of the filtration process that use micro-flocculation with dual-size foam glass.

Determination on inhibition effects of coagulants used in wastewater treatment plants on anaerobic digester.

Domestic wastewaters causing pollution contain inorganic and/or organic materials. When the domestic wastewater outflows to the receiving waters, it causes physical, chemical, and biological pollution in them, and deteriorates the ecological balance of those waters. In the treatment of wastewater, various treatment methods are available depending on the pollution strength of the wastewater. Besides mechanical and biological methods, wastewater treatment with physicochemical methods is still one of the most effective and economical options. Particularly in wastewater with a high concentration of suspended solids, this method is very successful, and obtaining high suspended solids removal efficiencies is very possible. In this study, the effects of the use of coagulant and coagulant aid to be used in a treatment plant where domestic wastewater treatment is carried out are determined to increase the treatment efficiency of a biological treatment that comes later in the stages of the treatment. The effluent of the pre-settling tank may contain a lot of suspended solids. This presence of excess suspended solids decreases the efficiency at other levels of treatment and causes energy loss. In the experiments, the standard jar and inhibition tests are done as a method. As a result of the conducted studies, it is determined that the FeCl3, Synthetic coagulant LP 526, FeClSO4, and the combination of anionic polyelectrolyte yield the best results in the removal of the parameters of chemical oxygen demand (COD), total suspended solids (TSS), and volatile suspended solids (VSS). While FeCl3, APE 65, APE 85, Synthetic coagulant LP 526, and FeClSO4 did not show any inhibition effect in the sludge, APE 67, CPE 84, and (Al2(SO4)3 are found to cause inhibition in the sludge.

Evaluating Electrocoagulation Process for Water Treatment Efficiency Using Response Surface Methodology

The electrocoagulation process became one of the most important technologies used for water treatment processes in the last few years. It’s the preferred method to remove suspended solids and heavy metals from water for treating drinking water and wastewater from textile, diary, and electroplating factories. This research aims to study the effect of using the electrocoagulation process with aluminum electrodes on the removal efficiency of suspended solids and turbidity presented in raw water and optimizing by the response surface methodology (RSM). The most important variables studied in this research included electrode spacing, the applied voltage, and the operating time of the electrocoagulation process. The samples were taken from the Al Qadisiyiah water treatment plant. The treatment set up was in a batch mode; two parallel plates of aluminum were used as electrodes. Experimental results showed that the maximum removal efficiency of 96% for turbidity and 97% for TSS were obtained at operating time 60 minutes, voltage 30 V, and electrode spacing 1.7cm. Two models for predicting removal efficiency obtained, the first model was for turbidity with a correction factor of 94.7%, and the second one was for the TSS with a correction factor of 94.85%.