TSS Removal Research Articles

Effect of particle size distribution and acid treated coal bottom ash on TSS and COD removal from textile effluent using fixed bed column

Most wastewater treatment plant (WWTP) of textile industries in Bandung area have not operated optimally due to several reasons, such as high processing load and high operational cost. On the other hand, bottom ash which is a major pollutant generated from coal-fired boiler has good potential as adsorbent. In this paper bottom ash obtained from a textile industry in Bandung has been used to remove the organic contaminant from textile effluent in order to reduce the burden to WWTP. The ash was treated using acid solution prior to adsorption and filtration of waste, in order to avoid leaching of its metal content by wastewater and to enhance its adsorption capacity. The best contact time on COD removal and the adsorption capacity were obtained in batch processes. The effect of bed particle size to pressure drop, the influence of contact time, bed particle size on TSS filtration and COD removal were also studied using a fixed bed column. Acid treatment of ash was carried out using 0.25 M HCl solution. One gram of bottom ash was leached by 20 mL of acid solution to give 1.402 ppm of chromium effluent (below the threshold limit of 5 ppm). The highest adsorption of acid-treated bottom ash on Rhodamine B 233 was achieved on 2 h duration of adsorption, with adsorption capacity of 15.87 mg Rhodamine/g ash). Filtration of wastewater on fixed bed of finer grain (1.0625 mm) as well as coarser grain (1.200 mm) provided 55 % TSS reduction, 30% volumetric rate reduction, and 95% COD reduction in less than one hour.

INFLUENCE OF SUBSTRATE AND SPECIES ARRANGEMENT OF CULTIVATED GRASSES ON THE EFFICIENCY OF HORIZONTAL SUBSURFACE FLOW CONSTRUCTED WETLANDS

We aimed to evaluate the efficiency of six different horizontal subsurface flow constructed wetlands (HSSF-CWs), with different substrates (gravel and crushed PET bottles), which also varied in relation to the presence and arrangement of plant species (elephant grass and Tifton 85 bermudagrass) in the removal of pollutants from a bulk milk cooling tank (MTWW). Each bed was fed at a flow rate of 0.18 m3 d-1 and average organic load rate (OLR) of 318 kg ha-1 d-1 of BOD5, with hydraulic detention time (HRT) of 1.84 days in the gravel-filled HSSF-CWs (CWS-G) and 2.97 days in the PET-filled HSSF-CWs (CWs-P). The CWs-P were as efficient as the CWs-G in the removal of BOD5, COD, Total-P, and K-Total, being in some cases even more effective (turbidity, TS, TSS and Na). The gravel, on the other hand, provided greater removals of Total-N from the MTWW. In the non-cultivated CWs and those cultivated with elephant grass, in its first half and Tifton 85 grass in its second half, there were higher average efficiencies in COD and TSS removal sand, in the latter, the highest average removal of Total-N.

A small-scale low-cost water treatment system for removal of selected heavy metals, bacteria and particles

Abstract Two low-cost sand filtration systems incorporating granular activated carbon (GAC) and non-woven geotextile respectively were assessed for Point-of-Use water treatment. Laboratory scale models were evaluated in respect of selected heavy metals, bacterial and particulate removal when exposed to surface water for five months. System 1 (ISSF-1) incorporated GAC and system 2 (ISSF-2) incorporated non-woven geotextile. Filter-mats were placed on the filter surfaces of both systems. Flow rates ranged between 8 and 15 L/h for longer water contact with the GAC and bio-layer. On average, E.coli removals were 96% and 94%, while fecal coliform removals were 96% and 95%, by ISSF-1 and ISSF-2 respectively. Average TSS removals were 98% and 92%, while turbidity removals were 97% and 91%, by ISSF-1 and ISSF-2 respectively. Average metal removals were: Arsenic (21%), Cadmium (82%), Lead (36%), Iron (65%) and Manganese (94%) by ISSF-1, Arsenic (17%), Cadmium (<LoD), Lead (<LoD), Iron (92%) and Manganese (98%) by ISSF-2. Both models consistently met turbidity guideline (5 NTU) and can remove significant amounts of particles. Both systems can treat the poor-quality water used to provide relatively safe water and could be improved further for heavy metal removal. However, to guarantee continued safe-water supply, supplementary treatment by chlorination is recommended.

Removal Efficiency of Nitrite and Sulfide Pollutants by Electrochemical Process by Using Ti/RuIrO<sub>2</sub> Anode

In general, wastewater treatment by physical, chemical and biological methods are only focused on TSS, BOD and COD removals that the effluent still contains anion pollutant as NO2- and S2-. Electrochemical technology is a proper method for those pollutants treatment due to its fast process, easy operation and minimum amount of sludge. Electrocatalytic reactor with 8 L capacity using Ti/RuIrO2 cylinder as anode and Fe plate as cathode was arranged and applied to treat anion pollutants. Hydraulic retention time (30, 60, 90 and 120 min), salt concentration (250, 500 and 750 mg/L) and voltage (4, 5, and 6 V) were chosen as operation variables and NO2- and S2- concentrations as parameter indicators. Nitrite removal efficiency reached 75 and 99.7% after 60 and 120 min of electrolysis, respectively, while sulfide could obtain higher efficiency, i.e., 97 and 99.9% after 60 and 90 min, respectively, at operation variables of potential of 5 V and salt of 500 mg/L. Removal process is dominated by indirect oxidation mechanism by HClO/ClO- oxidators generated at anode surface as intermediate products. The lifespan of electrode and electric consumption are two main factors of operation cost. Electric consumed was 0.452 kWh per 1 g nitrite removed.

SUSTAINABLE APPROACH OF RECYCLING PALM OIL MILL EFFLUENT (POME) USING INTEGRATED BIOFILM/MEMBRANE FILTRATION SYSTEM FOR INTERNAL PLANT USAGE

Palm oil mill effluent (POME) is a massive problem to the environment, primarily waterway as it contains a considerable range of pollutants. Therefore, while enjoying the high revenue from palm oil industry, the palm oil industry responsibility towards the POME treatment must be taken into consideration. Along with the development of sustainable engineering concept, many researchers have focused on inventing a system that does not compromise the natural environment or the ability of future generations to meet their own needs. This study aimed to investigate the feasibility of using integrated biofilm treatment/membrane filtration process in producing recyclable and reusable water by manipulating the biofilm carrier type and the biofilm treatment HRT. The combined system of biofilm and membrane had delivered 98.6, 99.98, 97.5, 100, and 99.87% of COD, Turbidity, MLSS, TSS, and ammoniacal nitrogen removal, respectively. The produced permeate from aerobic POME remediation by biofilm/ membrane filtration system meets the III and IV class of the National Water Quality standards of Malaysia for water supply (Extensive treatment is required), and fishery (livestock drinking) purpose.

Influence of experimental parameters in the treatment of tannery wastewater by electrocoagulation

ABSTRACTElectrocoagulation (EC) was carried out using a laboratory-scale system for the treatment of tannery wastewater (TWW). Statistical experimental design was applied to investigate the effect of various operating parameters (OP) including initial pH, electrode material (EM), and effluent load (EL). Analysis of variance showed that the proposed models fitted well with the removal of COD and TSS; high coefficient of determination values were obtained (R2 > 0.99). The results show that the EL was an important factor affecting pollutant removal from TWW. COD and TSS removals are principally controlled by EL and initial pH. However, EM has no significant effect on TSS removal and its effect on COD removal is contracted at neutral pH medium. The treatment of TWW with an EL = Eff.am (COD0: 5634 mg l−1, TSS0: 910 mg l−1, and Cr0: 75 mg l−1) at neutral pH allows removal of more than 64%, 96%, and 99% of COD, TSS, and chromium, respectively, as well as a significant color reduction. Working at 68 mA and after 15 min of electrolysis process time, under optimal OP, the EC reactor operational cost is 2.01 US$ m−3. EC technique coupled to an equalization basin could be recommended as an effective process on TWW treatment.

Efficiency analysis of the electrocoagulation and electroflotation treatment of poultry slaughterhouse wastewater using aluminum and graphite anodes.

The application of electrocoagulation (EC) and electroflotation (EF) was investigated for the treatment of poultry slaughterhouse wastewater in a bench scale unit cell electrolyzer with different EC-to-EF ratios at current densities of 3, 9, and 15mAcm-2. The EC-to-EF ratio was controlled by current reversal using aluminum and graphite electrodes. The electrochemical treatment showed satisfactory removal efficiencies for Al coagulant loads greater than 51.8mgL-1. The 4/5 EC to EF ratio (69.1mgL-1 Al and 32.2NmLL-1 additional EF gas) and 3/5 (51.8mgL-1 Al/64NmLL-1 additional EF gas) presented the best results for the removal of COD (76-85%), color (93-99%), and turbidity (95-99%), with the additional benefit of reducing the electrode consumption and sludge disposal costs proportionally to the EC-to-EF ratio. The effects of the EC-to-EF ratio and the current density on efficiency of the electrochemical treatment for the removal of COD, apparent color, turbidity, TSS, TSD, and NH3-N were discussed in the light of the physicochemical and electrochemical processes underlying the removal mechanism for each parameter. In particular, the blow-off mechanism seems to play an important role in the NH3-N removal, whereas indirect electrooxidation mechanism accounts for a fraction of the soluble COD removal for the electrodes configuration used in the treatment.

Optimization of hydraulic efficiency and wastewater treatment performances using a new design of vertical flow Multi-Soil-Layering (MSL) technology

The study gives a new method for contaminants removal from domestic wastewater using a novel design of Multi-Soil-Layering (MSL) eco-technology. Two MSL reactors were built and operated under laboratory conditions: a standard and modified MSL design (S-MSL and M-MSL). A tracer test using KCl indicated varying degrees of dispersion, short-circuiting, dead space, effective volume ratio and hydraulic efficiency in two MSL reactors. The new MSL design was found to be most effective in improving hydrodynamic flow conditions. The M-MSL reactor increased the mean HRT from 15.79 to 22.07 h, and decreased the dead space rate from 38% to 8%. The early arrival of the distribution peak, indicator of short-circuiting, was mainly noted in the case of S-MSL RTD which is around 57% of the nominal HRT. A high dead space rate was found to occur in the S-MSL reactor, and produced a poor hydraulic performance. The large difference between the nominal and mean HRT confirms the presence of zones of stagnation in the S-MSL system. The new MSL design increased the effective volume ratio from 0.62 to 0.92. The hydraulic efficiency was increased from 0.26 to 0.84 and reached a good level (λ ≥ 0.75) highlighting the excellent hydraulic performance of the M-MSL design. Obtained results revealed that M-MSL had an optimal hydraulic profile and enhanced sanitary and physicochemical performances compared to S-MSL. The mean log reduction of total coliforms, fecal coliforms and fecal streptococci was increased from 1.25, 1.26 and 1.15 log units for the S-MSL to 2.36, 2.38 and 2.11 log units for the M-MSL reactor. Both MSL reactors achieved high and satisfactory TSS and organics removal. The M-MSL reactor accomplished a 92% removal of TN, while the S-MSL achieved a slightly less effective result. The M-MSL reactor was also found to be more efficient in reducing TP by 98% compared to a removal rate of 76% in the S-MSL reactor. Therefore, the new design of MSL eco-technology could be adopted as an alternative to the current design for efficient domestic wastewater treatment.

Mitigation and treatment of pollutants from railway and highway runoff by pocket wetland system; A case study

This study performed in Sapanca Lake catchment area, used as a drinking water resource. Two highways located at northern and southern shores, and a railway at its south are significant sources of pollution. As a possible solution for protecting water quality a pocket wetland constructed and operated. Performances statistically interpreted by Spearman's Correlation test and univariate analysis of variance on collected data. The mean removal efficiencies obtaited were 52% (TSS), 4% (Nitrate), 26% (TN), −5% (TOC), 63% (TP), 4.5% (Chloride), 3% (Sulfate), 33% (Cr), 39% (Co), −19.5% (Ni), 7% (Cu), 55% (Zn), 36% (As), 38% (Cd) and 18% (Pb). TSS removal was in positive significant medium correlation with Co, Cu, Zn, and Pb removal respectively (p < 0.05). Other statistically significant positive high correlations calculated between removal efficiency of Nitrate–TN, Chloride–Sulfate, Cr–Co–Cu–As–Cd. According to ANOVA and Kruskal-Wallis test results, removal efficiencies of TSS and TOC partially affected by different temperature (p < 0.1 for TSS and p < 0.05 for TOC) and pH ranges (p < 0.1 for both removal efficiencies), TP removal efficiency significantly affected by different pH ranges (p < 0.001), and Chloride and Sulfate removal efficiencies were significantly (p < 0.001) affected by different temperature ranges. Regardless of geographical location and climatic factors, pocket wetland systems can be relied upon for minimizing heavy metals such as Cr, Co, Zn, As, Cd and Pb and critical pollutants such as TP and TSS caused by highway runoff.

Performance study on organic carbon, total nitrogen, suspended solids removal and biogas production in hybrid UASB reactor treating real slaughterhouse wastewater

The performance of slaughterhouse wastewater treatment was studied in Hybrid Upflow Anaerobic Sludge Blanket Reactor (HUASBR) consisting of polypropylene media as attached growth surface. During acclimation phase, the amount of real slaughterhouse wastewater was gradually increased, whereas the amount of synthetic wastewater was proportionally decreased in a mixed feed to the reactor. The batch performance was evaluated by feeding 1000 ml of raw slaughterhouse wastewater and observing consistent Chemical Oxygen Demand (COD) removal over a batch period of 72 h. After attaining maximum COD removal efficiency and maximum methane gas production, the reactor was operated under continuous mode with gradually increasing Total Organic Carbon (TOC) loading rate. The reactor showed steady increase in the TOC removal efficiency as well as incremental biogas production. In this study, TOC loading rate was varied in the range of (1.12–14.19)kg TOC/m3/d corresponding to decremental Hydraulic Retention Time (HRT) of (24–6) hours. The HUASBR enhanced the TOC removal efficiency in slaughterhouse wastewater up to maximum of 95.85% under the TOC loading rate of 6.97 kg TOC/m3/d for 10 h HRT. The TSS removal efficiency was observed to be in the range of (72–98) % throughout the study. Similarly, The TN removal was also recorded between (48–78) % out of all the continuous operations. The maximum methane gas production rate was observed as 61.5 L/d at 10 h HRT.

Composting leachate: characterization, treatment, and future perspectives

The increasing production of waste has led to one of the major environmental challenges of today: waste management. A solution to this problem is the composting of organic wastes. While the composting process transforms organic wastes into biologically stable compost, large amounts of highly contaminated leachates that present a direct risk to the environment are also produced. First off, this review discusses the origin and nature of contaminants found in composting leachates. In a general perspective, composting leachates are characterized by the presence of high concentrations of moderately biodegradable organic matter and nutrients and contain toxic pollutants such as heavy metals and plasticizers. Treatment technologies that have been studied are subsequently reported and discussed (treatment efficiencies and operating costs). This review highlights the lack of available solutions to efficiently remove all contaminants found in these leachates, which is a major concern considering the increasing number of composting facilities. While both, membrane bioreactors and reverse osmosis, show promising results with NH4, COD and TSS removals of > 70, > 85 and > 99.9%, respectively, the resulting effluent remains hazardous for the environment. Further studies are required to assess the use of a combination of biological and advanced oxidation process for the production of a safely disposable effluent.

PENGOLAHAN AIR LINDI DENGAN PROSES BIOFILTER ANAEROB-AEROB DAN DENITRIFIKASI

Most of the leachate treatment in Indonesia using pond system, that is maturation ponds, anaerobic ponds, stabilization ponds, and continued using wetland. The weakness of this technology is long retention time (between 30-50 days), thus the building a pond requires a wide area. In addition, the processed leachate is over quality standards to be discharged into the environment agency. To overcome these problems, one alternative is to use a combination of processing leachate within anaerobic-aerobic biofilter and denitrification. The technology is expected to shorten the residence time, so that the land required for the processing of leachate is not too extensive . The processed leachate is also expected to meet the quality standards are allowed to be discharged into the environment. Leachate treatment using anaerobic - aerobic biofilter and the denitrification process with a total hidraulic retention time of 12 day, the retention time in the anaerobic reactor 8 ( eight ) days , the retention time in the aerobic reactor 3 (three) days and retention time in the denitrification reactor 1 (one) day can be generated COD removal efficiency of 97 %, ammonia removal efficiency of 97.56 %, TSS removal efficiency 87.5 % , and nitrate removal efficiency of 86.4 % Keywords : Anaerob-aerob biofilter, denitrification, leachate.

Performance and mechanism of free nitrous acid on the solubilization of waste activated sludge.

Free nitrous acid (FNA) is a promising chemical reagent for excess sludge reduction. The distinctive properties of FNA treatment on waste activated sludge (WAS) disposal have previously been demonstrated, however, the cellular response, permeabilization, and disruption caused by low-concentration FNA and the direct cell solubilization of WAS using concentrated FNA should be better understood. In this study, the parameters that influence the sludge solubilization efficiency were optimized over a wide range of FNA concentrations. The sludge solubilization efficiency was found to be superior when the sludge was exposed to FNA (when the dosage of NaNO2 was 0.12 g g−1 TSS and the pH was 3.0, FNA = 20.94 mg L−1) for 10 h at 25 °C, and the TSS removal and COD dissolution efficiencies were found to be prominent at 38% and 7%, respectively. In the FNA treatment of WAS, some FNA-tolerable cells increased the K+, Ca2+, and H+ effluxes under low concentrations of FNA, and finally achieved ion homeostasis based on the results using a scanning ion-selective electrode measurement technique. This could cause the cells in WAS to maintain cytoactivity and integrity under a low-concentration FNA treatment. Furthermore, flow cytometry was used to assess the permeabilization and disruption of sludge cells toward a concentration gradient of FNA. Flow cytometry results indicated that cells in sludge flocs were disrupted within 30 minutes when the FNA concentration was above 8 mg L−1.

Role of UASBs in River Water Quality Conservation in India

Appropriate low-cost treatment technologies are a prerequisite for sound management of natural water resources against pollution in developing countries. Among the existing technologies available, UASB is found to be economically viable for India when considering all factors including operation and maintenance cost and treatment efficiency. However, this technology suffers setbacks in meeting the effluent guidelines prescribed by the government of India. Post treatment is supplemental to this process to meet the effluent standards in terms of removal of organic matter, suspended solids, pathogens and nutrients. Recent stringent effluent guidelines notified by the Ministry of Environment, Forests and Climate Change, Government of India has further reduced the limits of BOD by 3 times, COD and TSS by 5 times, NH4-N and total Nitrogen by 10 times as compared to the previous guidelines. Fecal Coliforms has been specified as &lt;100MPN/100mL. In this paper, the present scenario of UASB based STPs and their role in river conservation is reviewed against the backdrop of stringent effluent guidelines. The minimum removal rates of BOD, COD and TSS in these plants are around 42 – 44% and the average removal rates are reported to be 66%, 61% and 65% respectively. The enhanced removal of BOD (97%), COD (98%) and TSS has been reported in STPs in conjunction with post treatment facilities such as facultative aerated lagoons, aeration tanks and polishing ponds.

Development of Natural Fiber as a Filter Media in Removing Organic Pollutants from Greywater

Greywater is a wastewater originating from shower, bathtub, bathroom sink, kitchen sink and laundry. Despite the fact of wastewater in Malaysia may also include a complex mixture of organic matter, suspended solids, bacteria and common household chemicals, when used wisely and in a manner that is protective to public health and the environment, it can helps preserve limited water supply. This study aims the efficiency of adsorption of organic pollutants in greywater by using natural fibers such as Kenaf dust and Chitosan powder to treat the colour of water and the cause of odours from the greywater. The objective of this research is to identify the characteristics of greywater according to standard effluent discharge, as well as to characterize the physical properties of Kenaf (Hibiscus Cannabinus L.) and to determine the percent removal parameters of greywater by using Kenaf dust and Chitosan powder as organic removal. Raw greywater samples were taken at main drain Kompleks Parit Raja. The results for raw greywater samples obtained such as COD (253 mg/l), TSS (1800 mg/l), pH (5.89) and turbidity (47.5 NTU) were compared to Effluent Standard Discharge (EQA 1974). The COD removal efficiencies by using kenaf dust and chitosan powder amounted to 51% and 50 %, also TSS removal 89% and 100%. The pH and turbidity amounted to 6.76 and 7.04, 46 NTU and 4.46 NTU respectively. The overall removal of organic pollutants increased with different mass of adsorbents, then the optimum adsorbents were selected 30%, 40% and 50% to form as beads.

Stormwater solids removal characteristics of a catch basin insert using geotextile

Suspended solids in urban runoff have multiple adverse environmental impacts and create a wide range of water quality problems in receiving water bodies. Geotextile filtration systems inserted within catch basins have the potential to mitigate these effects, through flow attenuation and pollutant removal. This study modelled a catch basin in a column and assessed the hydraulic and solids removal characteristics of a new type of non-woven geotextile (NWG1) in the capture of solids from stormwater runoff. The new geotextile was compared with two others readily available on the market (NWG2, NWG3). Synthetic stormwater containing TSS (200mg/L) was used with two particle size distributions of 0–180μm (P1; D50:106μm) and 0–300μm (P2; D50:150μm). The results revealed that the desired stormwater TSS concentration (<30mg/L; ANZECC, 2000) could be achieved with a short ripening process (e.g., 1–2kg/m2 of suspended solids loading) for trials using the larger particle size distribution (P2). In addition, 36% more suspended solids were captured in trials using the soil with the larger range of particle sizes (P2) than for the soil with smaller particle sizes (P1). Geotextile fibre pattern appeared to have a significant influence on the TSS removal capacity. The NWG1 has higher permittivity than NWG3 but similar to NWG2. NWG1 could capture overall more TSS (which also resulted in earlier clogging) than NWG2 and NWG3 because of the special fibre structure of NWG1. The experimental data shows that these geotextiles may start to clog when the hydraulic conductivity reaches below 1.36×10−5m/s. The overall hydraulic performances of geotextiles showed that the NWG1 has better potential for use in CBIs because of its higher strength and multiple reuse capability.

Hybrid natural systems for treatment of olive mill wastewater

AbstractBACKGROUNDThis study examines the efficiency of various natural systems in treating untreated OMW before it is discharged to the environment. The experimental set‐up consisted of two hybrid pilot‐scale natural systems. The first hybrid system (HS‐A) comprised two open tanks (OTs), one vertical flow (VF) constructed wetland (CW) and one free water surface flow (FWS) CW and the second one (HS‐B) comprised two OTs and one FWS CW.RESULTSRegarding the HS‐A system, TSS, COD, TKN and phenols (PHE) removals in the two OTs were 83.0%, 21.6%, 62.3% and 12.9%, and cumulative removals in the VF and FWS CW systems were 52.0%, 54.1%, 44.4% and 60.1%, respectively. Regarding the HS‐B system, TSS, COD, TKN and PHE mean removals in the two OTs were 80.7%, 32.2%, 64.1% and 24.7%, and in the FWS CW were 72.0%, 49.4%, 26.9% and 51.1%, respectively. The final pollutant effluent concentrations remained high for disposal in water bodies or reuse for irrigation; further reduction could be achieved by adding additional FWS CWs in series.CONCLUSIONHybrid natural systems can be used in efficiently and economically treating OMW. Such hybrid systems could be applied to small family‐owned olive oil producing enterprises to treat OMW economically. © 2017 Society of Chemical Industry

Performance Assessment of Moratuwa- Ratmalana Biological Nutrient Removal Industrial Wastewater Treatment Plant

This study evaluates the performance of Moratuwa-Ratmalana Biological Nutrient Removal (BNR) plant during the dry period of 2016. This treatment plant is 1st ever reverse A2/O (anoxic/ anaerobic/ aerobic) treatment plant in Sri Lanka which was established by the National Water and Drainage Board (NWDB) in 2013. This study was confined to the dry period. This study was carried out to achieve two objectives. First objective is to monitor and evaluate the overall efficiency of the treatment plant in terms of removing pollutants from the influent. Second objective is to analyze nitrogen and phosphorous removing ability in each compartment. Samples were collected weekly for a stretch of 15 weeks from February to May. The sampling method utilized in this study was ‘grab sampling’ and ‘composite sampling’. First samples from each three layers of each of the three compartments were collected through grab sampling and then composite samples for each layer was prepared by using the grab samples. Composite samples were used for final testing. In addition samples were also collected for influent and effluent from the composite sampler which is located in the treatment plant. The analysis was carried out to test for physical (pH, Temperature) and chemical (BOD, COD, TSS, TP, TN) parameters of each collected sample. The performance evaluation has indicated that 88.52% COD removal, 97.05% TSS removal, 94.12% BOD removal, 84.23% of TP removal and 81.65% of TN removal efficiencies have been achieved. Also the analytical measurements obtained of the treated effluent are compatible with the discharge water quality standards issued by CEA, Sri Lanka. In addition it was shown that each compartment of the treatment plant meets the design expectations regarding Nitrogen and Phosphorous removing abilities. Keywords: Wastewater Treatment, Plant performance, Reverse A2/O

Effect of Temperature on the Performance of an Up-flow Anaerobic Sludge Fixed Film (UASFF) Bioreactor Treating Palm Oil Mill Effluent (POME)

This study investigates the performance of anaerobic digestion of palm oil mill effluent (POME) in an up-flow anaerobic sludge fixed film (UASFF) bioreactor at four different temperatures (24, 38, 50 and 60 °C) under optimized operating conditions (feed flow rate (QF) of 1.5 L day and up-flow velocity (Vup) of 0.75 m/h). Influent COD concentration was 14150 mg/L. Six quality parameters viz. COD removal, methane yield, TSS removal, oil and grease removal, effluent volatile fatty acids (VFA) and pH were monitored as the process response. COD removal and methane yield of 92% and 0.325 CH4/g CODremoved day were achieved respectively in mesophilic temperature (38 °C) at HRT of 1.5 day. Higher values (94% COD removal and 0.331 CH4/g CODremoved day) were obtained under thermophilic condition (50 °C). A 94% oil and grease removal was achieved at a temperature of 50 °C while it was 85 and 65% at 38 and 24 °C, respectively. The granules structure and activity did not undergo any changes at temperature of 50 °C. An increase in temperature from 50 to 60 °C caused a detrimental effect on treatment efficiency as the methanogenic activity was relatively terminated within <6 days.

Performance assessment of a Canna indica assisted vermifilter for synthetic dairy wastewater treatment

Abstract Two lab-scale vertical flow vermifilter were designed, one aided with Canna indica (MAVF) and the other without it (VF), but Eisenia fetida was inserted in both the systems. The experimental phase continued for ten weeks with a hydraulic loading rate of 0.65 m3 m−2 day−1. Results indicated that MAVF possess maximum organic and nitrogen degradation capacity during the treatment process and it was working steadily without sign of clogging, but vermifilter without macrophyte (VF) was clogged within the first few weeks of its operation. Removal efficiencies of BOD were 80.6% for MAVF and 71% for VF, while for COD it was 75.8% and 66.1%, respectively. TSS removal for MAVF and VF was found to be 84.8% and 73.8%, respectively, but TDS removal was insignificant in both the filters. Interlayer analysis presented that maximum organics and solids removed in the 1st layer or worm active zone. MAVF removed 42.6% TN, and effluent NH4+-N concentration in MAVF and VF were as low as 8.4 mg/L and 13.2 mg/L, respectively. However, TP concentration in effluent increased gradually may be due to the actions of phosphorus solubilizing microorganisms (PSM) and phosphatase enzymes secreted by earthworm. Growth characteristics of C. indica and E. fetida were also observed during the experimental period. Different physical and biochemical changes in soil due to plant and earthworm activity were analysed through FTIR, SEM and humic component analysis. The performance of MAVF was found to be superior to VF with high longevity.