NTU Turbidity Research Articles

상수원수 및 정수처리공정별 가시아메바 분포특성에 관한 연구

The free-living amoeba and Acanthamoeba sp. are widely distributed in fresh water, soil, air and dust in the world. We studied distribution of amoeba from low Nakdong River(Mulgum and Maeri) and removal efficiency in water treatment process of Busan metropolitan city. During this investigation, water quality showed pH , water temperature , turbidity NTU, chlorophyll-a , BOD mg/L, COD mg/L and total coliform MPN/100 mL. The free-living amoeba were detected highly than Acanthamoeba sp., 11 out of 22 in raw water samples were positive (50%) for Acanthamoeba sp. from February 2005 to December 2005. The seasonal characteristics of tree-living amoeba and Acanthamoeba sp. in raw water were mainly distributed through the spring to the early fall. When tree-living amoeba and Acanthamoeba sp. were passed through the water treatment of pilot-plant, approximately 80% was sure to be removed through pre-ozonation, sedimentation, send filtration. 100% was removed after post-ozonation process. All of the isolated amoebas from Nakdong River were Acanthamoeba sp. AC311 18S ribosomal RNA gene with 98% nucleotide sequence homology.

Bentonite used as Adsorbent Agent of the Coupling Adsorption Ultrafiltration of the Secondary Effluents for their Reuse

This present study has for principal objective to treat secondary effluents of the Staoueli purification plant (Algeria) with the average characteristics in the Chemical Oxygen Demand (COD) is 76 mg L-1and 16 NTU of turbidity by adsorption ultrafiltration coupling for its reuse in irrigation or in industry to reduce the water demand. A mineral ultrafiltration tubular membrane of CARBOSEP M2 (15 Kg mol-1) in dynamic mode with a transmembrane pressure ΔP = 1 bar and a cross flow velocity U = 3 m sec-1 was used for this purpose. The adsorbent choice was made on an Algerian bleaching ground: the bentonite available on the market with low cost. It has sorptives properties and ions exchange with specific area 250 m2 g-1. In the first step, we considered the organic matter adsorption on bentonite in static mode (jar test). The optimal conditions were determined corresponding to the best elimination of the Chemical Oxygen Demand with a final value equal to 30.6 mg L-1 and turbidity, in jar test with 1.5 NTU value for an optimal bentonite concentration equal to 10 g L-1. In the second step, the adsorption ultrafiltration coupling, showed a final value in COD equal to 9.2 mg L-1 and final turbidity equal to 1.2 NTU. An improvement of the permeate flux was showed equal to 48.8% for the optimal concentration bentonite 10 g L-1. The adsorption significantly improves the ultrafiltration performances.

Application of the flexible fiber filter module (3FM) filter to sea water filtration

The new 3FM filter (Flexible Fiber Filter Module), implementing very fine nylon fibers as filtration media was tested at pilot scale for the first time on sea water. The objective was to improve the quality of raw sea water to produce water for injection into offshore wells for extraction purposes on oil-bearing fields. Particles larger than 5 microm must be removed from the water of injection to avoid clogging at the point of injection into the porous rock. The purpose of the tests carried out over several months at Palavas Les Flots (France) was to specify the optimal operating conditions of the 3FM filter. Various coagulants and combinations of reagents were tested at velocities ranging between 50 and 200 m(3)/m(2)/h (ground filtration velocity). On raw sea water of about 1 NTU turbidity and at velocities of 100 m(3)/m(2)/h, the filtered water contained about 300 particles per mL larger than 1 microm, and less than 15 particles larger than 5 microm per mL. The filter runs range from one hour to few hours, variable according to the raw water turbidity, the reagent dosing rate and the filtration velocity. Backwashes, a succession of air scours at high air flow rates combined with water phases, the total duration of which did not exceed 1 minute, were shown to be efficient during the three months testing period. 3FM filter performance was promising for many other possible applications.

Fabrication of glassy ceramic membrane filters for filtration of spring water with clogging phenomena

Ceramic membrane filters consisting of a filtration layer of varying thickness coated on a tubular porous support made of quartz-based materials and with a pore size of about 10 μm were fabricated. The filtration performance for spring water clarity was examined. The coatings were prepared by a filtration process with a dilute particle suspension of quartz-natural zeolite–lead borosilicate glass mixture. The filter matrix was of quartz type and the additives (frit glass and zeolite) made the filters with glassy pore walls as the sintering temperature applied was above their fusion temperature. The pores of the filtration layer have a relatively coarse size distribution and thus lead to clogging phenomena within the glassy pores during filtration operation. The pore clogging is a benefit for producing clear filtrate and the glassy pore walls favour the filter cleaning and recovery. It was observed that a sufficiently thick coating (>62 μm) was required for good enough filtrate clarity (0.2 NTU turbidity) and cleaning of the filter was possible by filtrate backflushing and air blowing.

Cloth Media Filtration and Membrane Microfiltration: Serial Operation

A combined system comprised of a cloth media filter and a membrane microfilter operated in series was used to treat secondary effluent. The study objective was to investigate the effect of premembrane filtration on the maximum sustainable membrane flux, transmembrane pressure, and effluent quality. The maximum sustainable time-averaged flux under predefined operating conditions (i.e., 15-minute process cycle, 24-hour chemical cleaning cycle, and 30-day intensive cleaning cycle) was 127 L/m(2)x h. Typical flux rates for secondary effluent ranged from 40 to 55 L/m(2) x h. Effluent water quality from the combined system was high and independent of membrane flux and influent quality. Average membrane effluent water quality values were 0.04 NTU for turbidity and 1.4 mg/L for 5-day biochemical oxygen demand. Neither total nor fecal coliforms were detected. Based on the results presented herein, prefiltration would provide an annualized cost savings of approximately 12% over microfiltration alone for a 3.8 x 10(3) m(3)/d treatment facility.

Effect of natural coagulant application on microfiltration performance in treatment of secondary oxidation pond effluent

A secondary oxidation pond effluent was treated using hollow-fibre crossflow microfiltration and coagulation process. Preliminary tests were carried out to find the optimum dosage of Moringa oleifera (a natural coagulant) for the coagulation process. Optimum dosage of Moringa oleifera was recorded as 100 mg/L for turbidity of secondary oxidation pond effluents ranging between 30 and 100 NTU. Turbidity removal achieved ranged between 50 and 57%. The performance of microfiltration coupled with coagulation using optimum dosage of Moringa oleifera was investigated. Better flux performance and lower rate of fouling were achieved when combining microfiltration with coagulation. Pseudo-steady state flux of 3 L/m 2.h at a relatively constant suction pressure of less than 0.6 bar was obtained after 300 h of filtration time. Results showed that the values of COD, BOD 5, alkalinity, VSS, TS, turbidity and pH in the filtrate were not influenced significantly by incorporation of coagulation using Moringa oleifera. The filtrate quality of about 50 mg/L COD, 25 mg/L BOD 5, 2 mg CaCO 3/L alkalinity, 1 NTU turbidity, 1 mg/L TSS and VSS respectively was produced when using microfiltration with and without coagulation.

PHYSICAL CHEMISTRY TREATMENT OF WASTEWATER FROM BIODIESEL PURIFICATION

Biodiesel, a biodegradable renewable product that obeys the carbon cycle, comes detaching more each time in the national scene due to the National Program of Production and Use of Biodiesel from the Federal Government, that stipulates a 2% obligatory addition of biodiesel to the Diesel oil starting at 2008. However the possibility of massive production of biodiesel in Brazil represents a serious threat to the drinking water sources, since one of the critical stages that guarantee the fuel quality is the laudering with water to the removal of biodiesel's by-products, such as the glycerin, the residual alcohol and the catalyst that still mixed in the renewable fuel. This water enters in the process of production not contaminated (some times also potable) and returns to the environment contaminated, presenting pH = 11, oils and greases near of 500 mg L-1, color equal to 3,000 mg L-1, turbidity equal to 905 NTU, beyond a chemical demand of oxygen equal to 16,564 mg L-1. This values are in disagreement with the Conama Resolution nº357. However after treatment it obtains pH = 6, nothing detected for oils and greases and color, 0,64 NTU for turbidity and chemical demand of oxygen equal to 5,000 mg L-1.

Domestic Wastewater Disinfection Using Solar Radiation for Agricultural Reuse

A study was performed in Viosa, Minas Gerais, Brazil, to determine the feasibility of using solar radiation to disinfect treated domestic wastewater (TDWW). The effluent from a residential development, after passing through a pre-treatment unit (bar screen and grit channel) and a septic tank, was used as supply. After the septic tank, the TDWW had mean values of 286 mg L-1 COD, 54 mg L-1 TSS, and 65 NTU turbidity. A square cement block reactor was constructed (located at 20 45' 14 S, 42 52' 53 W) and used to disinfect the reclaimed TDWW. Fixed depths of water (0.05, 0.10, 0.15, and 0.20 m) were tested at different exposure times from November 2004 to May 2005. Solar UV disinfection (SODIS) was effective in reducing mean concentration of indicator microorganisms, i.e., total coliform (TC) and Escherichia coli (E. coli), after 8 h of exposure to direct sunlight. Statistical analysis showed that the inactivation rates of E. coli did not significantly vary due to turbidity or dissolved oxygen. A model was developed to estimate the surviving E. coli population after SODIS from its initial population, depth of water treated, and solar energy received. The model indicated that, for a fluence accumulated of 32.91 MJ m-2, a 4 log reduction of E. coli population was achieved with a wastewater depth of 0.05 m in the SODIS reactor.

Optimization of Coagulation−Flocculation Process for Palm Oil Mill Effluent Using Response Surface Methodology

The coagulation-flocculation process incorporated with membrane separation technology will become a new approach for palm oil mill effluent (POME) treatment as well as water reclamation and reuse. In our current research, a membrane pilot plant has been used for POME treatment where the coagulation-flocculation process plays an important role as a pretreatment process for the mitigation of membrane fouling problems. The pretreated POME with low turbidity values and high water recovery are the main objectives to be achieved through the coagulation-flocculation process. Therefore, treatment optimization to serve these purposes was performed using jar tests and applying a response surface methodology (RSM) to the results. A 2(3) full-factorial central composite design (CCD) was chosen to explain the effect and interaction of three factors: coagulant dosage, flocculent dosage, and pH. The CCD is successfully demonstrated to efficiently determine the optimized parameters, where 78% of water recovery with a 20 NTU turbidity value can be obtained at the optimum value of coagulant dosage, flocculent dosage, and pH at 15 000 mg/L, 300 mg/L, and 6, respectively.

Response Surface Methodology for the Development of Self-Nanoemulsified Drug Delivery System (SNEDDS) of All-Trans-Retinol Acetate

The purpose was to prepare, characterize, and optimize a self-nanoemulsified drug delivery system (SNEDDS) of a model lipophilic compound, all-trans-retinol acetate. As part of the optimization process, the main effects, interaction effects, and quadratic effects of the formulation ingredients were investigated. Method. A three-factor, three-level Box-Behnken design was used to explore the quadratic response surfaces and construct a second-order polynomial model in the form: Y = A + A1X1+ A2X2+ A3X3+ A4X1X2+ A5X2X3+ A6X1X3+ A7X12+ A8X22+ A9X32+ E. Amount of added oil (X1), surfactant (X2), and cosurfactant (X3) were selected as the factors. Particle size (Y1), turbidity (Y2), and cumulative amount of the active ingredient emulsified after 10 (Y3) and 30 (Y4) min were the observed variables. Response surface plots were used to demonstrate the effect of factors (X1), (X2), and (X3) on the response (Y4). Amount of added soybean oil (X1), Cremophor EL (X2), and Capmul MCM-C8 (X3) showed a significant effect on the emulsification rates, as well as on the physical properties of the resultant emulsion (particle size and turbidity). Observed and predicted values of Y4 obtained from the constructed equations were in close agreement. Response surface methodology was then used to predict the levels of factors X1, X2, and X3 under the constrained variables for an optimum response. Applied constraints were 0 < Y1 < 0.5, 1 < Y2 < 20, 60 < Y3 < 80, and 90 < Y4 < 100. The predicted values were 0.0704 µm for particle size (Y1), 18.95 NTU for turbidity (Y2), 88.88% for drug release after 10 min (Y3), and 110.7% drug release after 30 min (Y4). Two new formulations were prepared according to the predicted levels. The observed and predicted values were in close agreement.

Removal of natural organic matter (NOM) in drinking water treatment by coagulation–microfiltration using metal membranes

Drinking water sources in Norway are characterized by high concentrations of natural organic matter (NOM), low pH, low alkalinity and low turbidity. The removal of NOM is therefore in many cases a general requirement in producing potable water. Drinking water treatment plants are commonly designed with coagulation direct filtration or with NF spiral wound membrane processes. This study has investigated the feasibility and potential of using inorganic metal microfiltration membranes in a submerged membrane configuration with coagulation pre-treatment for drinking water production. Variations in operating modes and conditions were tested, from dead-end operation to semi sequencing batch operation using air scouring and backwashing cycles for membrane cleaning and fouling control. Fluxes around 180 LMH at transmembrane pressures below 0.3 bar where achieved over production cycles in excess of 50 h. Treatment efficiencies in general showed >95% colour removal, ∼85% UV removal, 65–75% TOC removal and <0.2 NTU turbidity and non-detectable suspended solids in the permeate. The initial results show that MF metal membranes is an interesting alternative to sand filtration in coagulation/direct filtration for treating drinking water.

Use of Transparency Tubes for Rapid Assessment of Total Suspended Solids and Turbidity in Streams

ABSTRACT Studies were conducted to evaluate the use of transparency tubes to predict total suspended solids concentrations (TSS) and NTU turbidity in streams. Linear regression of data collected from 29 sample stations (12 streams) in northeast Ohio revealed a highly predictive correlation for both parameters using the Ohio Sediment Sticko. Laboratory studies showed significant differences between water clarity readings among individual observers using the Ohio Sediment Sticko. The type of visual end point target used in the tube had no effect on water clarity readings. A table to predict TSS concentrations based upon water clarity was developed for the Ohio Sediment Sticko. A comparison of three tubes of differing design (e.g., Minnesota Pollution Control Agency tube, NOAA GLOBE tube, and Ohio Sediment Sticko) found no significant differences in the relationship of water clarity measurement vs. TSS concentrations or NTU turbidity among tubes. Our data indicate that predictive equations developed for the Ohio Sediment Sticko can be applied with statistical confidence to both the MPCA tube and the NOAA GLOBE tube. When appropriately used, transparency tubes can be an effective and inexpensive monitoring tool to estimate relative sediment loads to lakes from different watersheds.

How particles affect UV light in the UV Disinfection of Unfiltered Drinking Water

This study assessed the impact of suspended particles on both ultraviolet (UV) dose transmission and spectrophotometric absorbance measurement for unfiltered raw water with turbidity up to 10 ntu. Results from bench‐scale collimated beam experiments indicated that a low percentage of total incident UV light was attenuated by particles at 5 ntu turbidity. However, at a set applied UV dose, when particles were added to achieve turbidity from 1 to 10 ntu, the average dose in the collimated beam reactor decreased from 5 to 33%, respectively. This suggests that spikes in particles entering a UV reactor, if not adjusted and accounted for, may compromise lethal delivery of UV energy. UV absorbance coefficients, measured using direct and integrating sphere spectroscopy (which accounts for scattering effects by particles) were significantly different, suggesting that suspended particles in unfiltered water both absorb and scatter UV light. When absorbance, measured using the direct method, was used to model the average irradiance in a UV reactor, the average UV irradiance was underestimated by 3 to 20% at turbidity of 3 to 10 ntu, respectively, compared with irradiance calculations made using integrating sphere absorbance measurements. This analysis suggests that UV systems designed based on direct absorbance measurements of unfiltered waters with turbidity above 3 ntu may be overly conservative.

An analysis of particle monitor sensitivity in potable water treatment

The sensitivity of particle counters, relative to conventional turbidimeters, is shown to follow an inverse power relationship with turbidity. It is argued that particle counters are best used as fine-tuning instruments below 0.1 NTU turbidity. A sample9s particle size distribution is also shown to influence monitor sensitivity. The model provided can be used to assess the value of using particle counters at a treatment works. It can also be used to compare the sensitivity of different particle monitors as well as anomalous particle monitor readings.

Examination of plant performance and filter ripening with particle counters at full‐scale water treatment plants

Filter performance has traditionally been assessed using turbidity as the main water quality parameter. However interest in process optimization and the ability to accurately monitor filtration and particle removal has led to particle counting becoming increasingly more popular. The objective of this research was to evaluate filtration performance and filter ripening at four full‐scale water treatment plants. Most of the plants investigated in this study were capable of achieving 2 log total particle removal as well as an effluent turbidity of 0.1 NTU. In some cases 2 log removal was achieved in the lower particle size ranges of 2–5 and 5–10 μm. Log removals in this study compare particle counts in the filtered and raw water. For water treatment plants that do not filter to waste, the ripening period following a filter backwash represents a time where the plant may be most vulnerable to breakthrough of waterborne pathogens. For the plants studied, the ripening period which was defined as the time required to reach peak particle removal and a turbidity of 0.1 NTU, were very similar in duration. The ripening period generally lasted for one hour after the backwash event had been completed. Because the times to reach 2 log total particle removal and 0.1 NTU are similar, the practice of using 0.1 NTU turbidity as a measure of filter ripening may be a useful benchmark for utilities that do not have particle counters.

Application of microfiltration with a novel fouling control method for reuse of wastewater from a large-scale resort complex

A study was conducted to investigate the treatability of a new microfiltration system utilizing agitator-induced flushing of the membrane to prevent fouling for wastewater reclamation. A hollow-fiber membrane was immersed in the tank and permeate was filtered through the membrane by intermittent suction using a pump. Influent from the large-scale resort complex was used. In the tank an agitator was operated at 350 rpm, with clockwise (4s) - stop (1s) - counter-clockwise (4s) rotation cycle. Membrane pore size, permeate flux and suction mode were studied. The optimal operational setting was determined to be 0.02 m/h flux, with 10-min suction and 2-min idle permeate pumping cycle. This setting was capable of 77 days of continuous operation without chemical cleaning. Below 20 mg/L of COD, 3.5 mg/L of TOC, 0.2 NTU of turbidity and no suspended solids were contained in the effluent. This system was adequate for the reuse of wastewater for secondary applications such as in toilet flushing.

Treatment of domestic wastewater using microfiltration for reuse of wastewater

This study was conducted to evaluate the applicability of microfiltration in treating domestic wastewater for reuse. A hollow fiber microfiltration membrane was used in the pilot test. The pore size of the membrane was 0.1 μm and effective surface area was 20 m 2. The maximum capacity of the pilot plant was 10m 3/d. The microfiltration system could be operated for 120 days without any cleaning procedure. It was found that agitation in the membrane tank had an effect on fouling prevention. In particular, the bi-directional agitation significantly reduced fouling. Chemical cleaning was effective in recovering of permeate flux and resistance, but in spite of chemical cleaning, fouling slowly progressed. According to the particle size distribution, in the membrane tank particles were transformed into smaller size by agitator-induced shear force. Based on mass balance analysis, about 60% of dissolved TOC mass removal in the system was attributed to biodegradation, indicating its important role. But suspended solids and colloidal matter were removed by the sieve mechanism of the membrane. Effluent quality was found to be lower than 30 mg/L of COD, 10 mg/L of BOD, 10 mg/L of TOC, 1 NTU of turbidity and 2 mg/L of SS, respectively. It satisfies the standard for wastewater reuse.

Wastewater reclamation at Rancho Murieta, California; golf course irrigation with upgraded pond effluent meeting California's strictest requirements for wastewater reuse

Rancho Murieta is an exclusive 1,400 ha (3,500 acre) master-planned golf-course-oriented community and is located approximately 39 km (24 miles) southeast of Sacramento, the capital of California. The community located along the banks of the Cosumnes River, one of the last pristine rivers in California, is situated in the great Central Valley of California which enjoys a Mediterranean-like semi-arid climate. The community has a present population of 3,500 people and is projected to have an ultimate population of 15,600. The Rancho Murieta Community Services District provides wastewater collection treatment and disposal services, among others within the community. In the early 1980s, the District obtained 55 ha (135 acres) of land for a wastewater treatment facility from the original developer of the community. Despite the immediate proximity of the plant to the Cosumnes River, the District was not allowed to discharge any plant effluent to the river. In favor of preserving the pristine qualities of the river, a “zero discharge” was required. Therefore, the District had to provide for some form of reuse of its effluent, a land disposal alternative. After considerable study, a plan was developed to integrate the community's two proposed championship golf courses into a comprehensive wastewater reclamation program. In addition to significantly decreasing the demand for treated domestic water within the community, a comprehensive program to irrigate the golf courses with reclaimed wastewater would also significantly lower the summertime demand for water from the river, thereby providing increased flows to downstream agricultural users along the river, a true “win-win” situation for all parties concerned. In order to provide treatment to an acceptable level for irrigation of golf courses surrounded by dwellings, it was decided that a tertiary treatment plant would be designed to meet California's wastewater reclamation requirements. The current treatment plant was constructed in three phases. California has very strict standards for effluent reuse and they are described in Title 22 of the California Code of Regulations. Use of reclaimed wastewater for most golf courses requires oxidation, coagulation, filtration and disinfection. The effluent has to meet a 2 NTU turbidity and 2.2 MPN/100 coliform standard. To comply with these standards, the District developed a unique treatment process that has allowed the District to be in full compliance since start-up without a single violation of the plant's discharge requirements. The initial treatment process consists of oxidation ponds. Mechanical aerators are located on the ponds to ensure that sufficient oxygen is provided at all times for treatment and most importantly for odor control. The pond effluent is discharged into two large reservoirs. These two reservoirs are sized to store wastewater for up to 150 days during periods of non-irrigation. When irrigation can be performed on the golf course, the tertiary treatment process is activated. It consists of dissolved air flotation for algae removal, filtration for polishing, and disinfection. Treatment design parameters, effluent quality results and capital and operating costs are presented.

Wastewater reclamation at Rancho Murieta, California; golf course irrigation with upgraded pond effluent meeting California's strictest requirements for wastewater reuse

Rancho Murieta is an exclusive 1,400 ha (3,500 acre) master-planned golf-course-oriented community and is located approximately 39 km (24 miles) southeast of Sacramento, the capital of California. The community located along the banks of the Cosumnes River, one of the last pristine rivers in California, is situated in the great Central Valley of California which enjoys a Mediterranean-like semi-arid climate. The community has a present population of 3,500 people and is projected to have an ultimate population of 15,600.The Rancho Murieta Community Services District provides wastewater collection treatment and disposal services, among others within the community. In the early 1980s, the District obtained 55 ha (135 acres) of land for a wastewater treatment facility from the original developer of the community. Despite the immediate proximity of the plant to the Cosumnes River, the District was not allowed to discharge any plant effluent to the river. In favor of preserving the pristine qualifies of the river, a “zero discharge” was required.Therefore, the District had to provide for some form of reuse of its effluent, a land disposal alternative. After considerable study, a plan was developed to integrate the community's two proposed championship golf courses into a comprehensive wastewater reclamation program. In addition to significantly decreasing the demand for treated domestic water within the community, a comprehensive program to irrigate the golf courses with reclaimed wastewater would also significantly lower the summertime demand for water from the river, thereby providing increased flows to downstream agricultural users along the river, a true “winwin” situation for all parties concerned.In order to provide treatment to an acceptable level for irrigation of golf courses surrounded by dwellings, it was decided that a tertiary treatment plant would be designed to meet California's wastewater reclamation requirements. The current treatment plant was constructed in three phases.California has very strict standards for effluent reuse and they are described in Title 22 of the California Code of Regulations. Use of reclaimed wastewater for most golf courses requires oxidation, coagulation, filtration and disinfection. The effluent has to meet a 2 NTU turbidity and 2.2 MPN/100 coliform standard. To comply with these standards, the District developed a unique treatment process that has allowed the District to be in full compliance since start-up without a single violation of the plant's discharge requirements.The initial treatment process consists of oxidation ponds. Mechanical aerators are located on the ponds to ensure that sufficient oxygen is provided at all times for treatment and most importantly for odor control. The pond effluent is discharged into two large reservoirs. These two reservoirs are sized to store wastewater for up to 150 days during periods of non-irrigation. When irrigation can be performed on the golf course, the tertiary treatment process is activated. It consists of dissolved air flotation for algae removal, filtration for polishing, and disinfection.Treatment design parameters, effluent quality results and capital and operating costs are presented.

Enhanced Coagulation Efficiency of Moringa Oleifera Seeds Through Selective Oil Extraction

In this laboratory based study, varying quantities of oil, corresponding to 20 % w/w, 25 % w/w and 30 % w/w kernel weight extracted from Moringa oleifera seeds ( S1, S2, S3) respectively were applied in the coagulation of model turbid water (kaolin suspension) and turbid river water samples from River Batang Kali and River Selangor in Malaysia to determine the percentage oil removed which gave the best coagulation efficiency. For model turbid water (kaolin suspension) coagulation of low turbidity of 35 NTU, medium turbidity of 100 NTU and high turbidity of 300 NTU, sample S2 gave the best turbidity removal corresponding to 91.7%, 95.5% and 99% respectively. Application of sample S2 to River Batang Kali with low initial turbidity of 32 NTU and high initial turbidity of 502 NTU gave a highest turbidity removal of 69% and 99% respectively. Application to River Selangor with medium initial turbidity- of 87 NTU and high initial turbidity of 466 NTU gave a highest residual turbidity' of 94% and 98.9%, respectively.Key words: Moringa oleifera seed, selective oil extraction, coagulation, model turbid water (kaolin suspension), river water, turbidity removal.