Raw Effluent Research Articles

Performance evaluation of membrane bioreactor for treating industrial wastewater: A case study in Isfahan Mourchekhurt industrial estate

Aims: The aim of this study was to evaluate a membrane bioreactor (MBR) system for optimization effluent quality by feeding of the influent (raw wastewater and anaerobic reactor effluent) in Isfahan - Mourchekurt Industrial Estate Centralized Wastewater Treatment Plant. Materials and Methods: The MBR was equipped with two flat sheets membrane with 0.2 μm pore size, were operated in parallel style and feed simultaneously with raw industrial wastewater (MBR1) and anaerobic reactor effluent (MBR2). The average organic loading rates in two reactors were 1.37 and 0.52 (kg chemical oxygen demand [COD]/m 3 .day), respectively. All analyses were implemented according to the standard methods procedure. Results: The average concentration of COD was lower than 100 mg/L and 50 mg/L in both reactor effluent, respectively, and it was 1000 MPN/100 mL for MBR1 and these were Conclusion: The MBR technology was used to treat the combined industrial wastewater was efficient, and its effluent can be perfectly used for water reuse. The MBR performance was improved by applying an anaerobic pretreatment unit.

Reduction of Toxic Parameters in Effluents Through Coagulation and Flocculation Using Natural Plant Fibers

The present study deals with the determination of physical and chemical parameters inthe treatment process of waste water by flocculation and coagulation processes using natural coagulants and assessing their feasibility for water treatment by comparing the performance with each other and with a synthetic coagulant. Initial studies were done on the synthetic waste water to determine the optimal pH and dosage, the activity of natural coagulant, followed by the real effluent from tannery waste. The raw tannery effluent was bluish-black in colour, mildly basic in nature, with high COD 4000mg/l and turbidity in the range 700NTU, was diluted and dosed with organic coagulants, AloeVera, MoringaOleifera and Cactus (O.ficus-indica).. The study observed that coagulant Moringa Oleifera of 15 mg/L dose at 6 pH gave the best reduction efficiencies for major physicochemical parameters followed by Aloe Vera and Cactus under identical conditions. The study reveals that the untreated tannery effluents can be treated with environmental confirmative naturally occurring coagulants.

Optimized Preparation of Directional Modified Attapulgite and its Application to Adsorbance of Humic Acid in Polluted Raw Water Effluent

Optimized Preparation of Directional Modified Attapulgite and its Application to Adsorbance of Humic Acid in Polluted Raw Water Effluent

Influent Constituent Characteristics of the Modern Waste Stream from Single Sources: Literature Review

A literature review was conducted to assess the current status of knowledge on the composition of raw wastewater and primary treated effluent (i.e., septic tank effluent) from single source onsite wastewater systems. The overall goal of this research project is to characterize the extent of conventional constituents, microbial constituents, and organic wastewater contaminants in single source onsite raw wastewater and primary treated effluent to aid onsite wastewater system design and management. Information obtained was evaluated using cumulative frequency distributions to compare individual constituent concentrations in various waste streams and by using data qualifiers to enable assessment of parameters that might affect single source waste stream composition. To supplement information on the single source raw wastewater and primary treated effluent composition, state agencies responsible for onsite wastewater regulation were contacted to assess the prevalence of different system types installed and in operation. Selected demographics that capture differences in lifestyle habits that could affect raw wastewater composition were also assessed. A large amount of data was captured by this literature review, however information gaps were identified. The information presented here will be used to guide future project monitoring and assessment of modern raw wastewater waste streams. This title belongs to WERF Research Report Series ISBN: 9781843397731 (eBook)

Synthesis of cryptocrystalline magnesite–bentonite clay composite and its application for neutralization and attenuation of inorganic contaminants in acidic and metalliferous mine drainage

The primary aim of this study was to synthesize cryptocrystalline magnesite–bentonite clay composite by mechanochemical activation and evaluate its usability as low cost adsorbent for neutralization and attenuation of inorganic contaminants in acidic and metalliferous mine drainage. The composite was synthesized at 1:1 weight to weight ratio. The capacity of the composite to neutralize acidity and remove toxic chemical species from synthetic and field AMD was evaluated at optimized conditions. Interaction of the composite with AMD led to an increase in pH (pH>11) and lowering of metal concentrations. The removal of chemical species was optimum at 20min of equilibration and 1g of dosage. The composite removed ≈99% (Al3+, Fe3+, and Mn2+) and ≈90% (SO42−) from raw mine effluent. Adsorption kinetics fitted better to pseudo-second-order kinetic than pseudo-first-order kinetic hence confirming chemisorption. Adsorption data fitted better to Freundlich adsorption isotherm than Langmuir hence confirming multisite adsorption. Gibbs free energy model predicted that the reaction is spontaneous in nature for Al, Fe and sulphate except for Mn. Geochemical model indicated that Fe was removed as Fe(OH)3, goethite, and jarosite, Al as basaluminite, boehmite and jurbanite, Al(OH)3 and as gibbsite and diaspore. Al and Fe precipitated as iron (oxy)-hydroxides and aluminium (oxy)-hydroxides. Mn precipitated as rhodochrosite and manganite. Ca was removed as gypsum. Sulphate was removed as gypsum, and Fe, Al hydroxyl sulphate minerals. Mg was removed as brucite and dolomite. It was concluded that the composite has the potential to neutralize acidity and attenuate potentially toxic chemical species from acidic and metalliferous mine drainage.

Occurrence, abundance and distribution of benthic macroinvertebrates in the Nyando River catchment, Kenya

A baseline study was conducted of the occurrence of macroinvertebrates at 26 sites in the Nyando River catchment in 2005–2006. A total of 13 orders and 16 families of Arthropoda, Mollusca, Platyhelminthes and Annelida were collected, with the order Ephemeroptera being most abundant in the up- and mid-stream reaches, followed by Hemiptera and Plecoptera respectively. The downstream sections of the river were dominated by Hirudinea and tubificids, as the water quality deteriorated mainly due to local land use, raw sewage effluent discharge and annual floods. Insects and annelids were the main invertebrates found and the extent of pollution increased from mid-section (Site 15) downwards as the river flowed into the Winam Gulf. Stringent management measures are required to safeguard the environment and ecosystems of Lake Victoria.

Recovering humic substances from the dewatering effluent of thermally treated sludge and its performance as an organic fertilizer

The biologic treatment of the dewatering effluent from thermally treated sludge is difficult due to the high concentration of refractory humic substances. On the other hand, humic substances are an important source of organic fertilizer. In this study, a novel process using ferric coagulant was developed to recover humic substances from dewatering effluent for use as an organic fertilizer. When ferric coagulant was applied to raw dewatering effluent, up to 70% of humic substances were enmeshed by hydrolyzed ferric ions at an optimum pH of 4.5. The proper mass ratio of iron ions to humic substances was 0.6. In the recovered material, humic substances accounted for 24.2% of the total dry solids, and the amount of phosphorus (equivalent phosphorus pentoxide) was 6.2%. Heavy metals and other components all met the legal requirements for organic fertilizer. When the recovered material was applied to soybeans, the germination and growth of the seeds was significantly improved.

Occurrence and removal of butyltin compounds in a waste stabilisation pond of a domestic waste water treatment plant of a rural French town.

The aim of this study was to investigate the fate and behaviour of butyltin pollutants, including monobutyltin (MBT), dibutylin (DBT), and tributyltin (TBT), in waste stabilisation ponds (WSP). The study was conducted as part of a baseline survey and included five sampling campaigns comprising bottom sludge and the water column from each pond from a typical WSP in France. Butyltins were detected in all raw wastewater and effluents, reflecting their widespread use. Our results revealed high affinity between butyltins and particulate matter and high accumulation of butyltins in the sludge taken from anaerobic ponds. The dissolved butyltins in the influent ranged from 21.5 to 28.1 ng(Sn).L(-1) and in the effluent, from 8.8 to 29.3 ng(Sn).L(-1). The butyltin concentrations in the sludge ranged from 45.1 to 164 and 3.6-8.1 ng(Sn).g(-1) respectively in the first and last ponds. Our results showed an average treatment efficiency of 71% for MBT, 47% for DBT, 55% for TBT. Laboratory sorption experiments enabled the calculation of a distribution coefficient (Kd = 75,000 L.kg-1) between TBT and particulate matter from the WSPs. The Kd explained the accumulation and persistence of the TBT in the sludge after settling of particulate matter. The continuous supply of contaminated raw wastewater and the sorption-desorption processes in the ponds led to incomplete bio- and photolytic degradation and to the persistence of butyltins in dissolved and particulate matrices throughout the survey period. It is thus recommended to use shallow ponds and to pay particular attention when sludge is used for soil amendment.

Evaluation of distribution and sources of sewage molecular marker (LABs) in selected rivers and estuaries of Peninsular Malaysia.

This is the first extensive report on linear alkylbenzenes (LABs) as sewage molecular markers in surface sediments collected from the Perlis, Kedah, Merbok, Prai, and Perak Rivers and Estuaries in the west of Peninsular Malaysia. Sediment samples were extracted, fractionated, and analyzed using gas chromatography mass spectrometry (GC-MS). The concentrations of total LABs ranged from 68 to 154 (Perlis River), 103 to 314 (Kedah River), 242 to 1062 (Merbok River), 1985 to 2910 (Prai River), and 217 to 329 ng g(-1) (Perak River) dry weight (dw). The highest levels of LABs were found at PI3 (Prai Estuary) due to the rapid industrialization and population growth in this region, while the lowest concentrations of LABs were found at PS1 (upstream of Perlis River). The LABs ratio of internal to external isomers (I/E) in this study ranged from 0.56 at KH1 (upstream of Kedah River) to 1.35 at MK3 (Merbok Estuary) indicating that the rivers receive raw sewage and primary treatment effluents in the study area. In general, the results of this paper highlighted the necessity of continuation of water treatment system improvement in Malaysia.

Toxicity evaluation of parboiled rice effluent using sperm quality of zebrafish as bioindicator

This study aimed to assess the acute toxicity of raw and treated wastewater generated by the rice parboiling industry using zebrafish (Danio rerio) sperm quality as a bioindicator. Toxicity bioassays were conducted comparing physicochemical parameters of sperm quality for zebrafish at sublethal conditions (n=150 fish, 50 per treatment). Acute toxicity was detected in all sperm quality parameters assessed for both raw and treated wastewater, when contrasted to the control (p<0.05). For zebrafish exposed to raw effluent, negative correlations with parameters of sperm quality were observed for the concentration of iron, phosphorus and total suspended solids (p<0.05). Salinity, the biochemical oxygen demand and the concentration of total suspended solids were negatively correlated with parameters of sperm quality for zebrafish exposed to treated effluent (p<0.05). In comparison with the levels observed for the raw effluent, most physicochemical parameters of the treated effluent were reduced to levels within the limits required by the environmental legislation. Despite the physical and chemical parameters measured in the treated wastewater meeting environmental legislation thresholds, acute toxicity persisted. These results show that the sperm quality can be used as a bioindicator for wastewater toxicity and release of wastewater to surface water could affect the fertility of fishes.

Potential application of a bioemulsifier-producing actinobacterium for treatment of vinasse.

Vinasse is a complex effluent created during production of ethyl alcohol, which can present serious pollution hazard in areas where it is discharged. A variety of technologies, many based upon recovery of the effluent via microbial pathways, are continually being evaluated in order to mitigate the pollution potential of vinasse. The present work reports on initial advances related to the effectiveness of the actinobacterium Streptomyces sp. MC1 for vinasse treatment. Alternative use of raw vinasse as a substrate for producing metabolites of biotechnological interest such as bioemulsifiers, was also evaluated. The strain was able to grow at very high vinasse concentrations (until 50% v/v) and remove over 50% of the biodegradable organic matter in a time period as short as 4 d. Potentially toxic metals such as Mn, Fe, Zn, As, and Pb were also effectively removed during bacterial growth. Decrease in the pollution potential of treated vinasse compared to raw effluent, was reflected in a significant increase in the vigour index of Lactuca sativa (letucce) used as bioremediation indicator. Finally, significant bioemulsifier production was detected when this strain was incubated in a vinasse-based culture medium. These results represent the first advances on the recovery and re-valuation of an actual effluent, by using an actinobacterium from our collection of cultures.

Impact of Biologically Treated Effluent on the Physico-chemical Quality of a Receiving Stream in Ile-Ife, Southwest Nigeria

This study was carried out to investigate the impact of biological treated effluent on the physico-chemical properties of receiving waterbodies and also to establish its suitability for other purposes. It focused on the changes of some physic-chemical variables as one move away from the point of discharge downstream of the waterbodies. Water samples were collected from 14 sampling stations made up of the untreated effluent, treated effluent and receiving streams (before and after treated effluent discharge) over a period of 6 months spanning the dry and rainy seasons. Analyses were carried out on the following: temperature, turbidity, pH, conductivity, major anions and cation, dissolved oxygen, percentage oxygen Saturation, biological oxygen demand (BOD), solids (total solids, suspended solids and dissolved solids), nitrates, phosphates, organic matter and flow discharge using standard analytical methods. The relationships between investigated sites with regards to their physico-chemical properties were analyzed using student-t statistics. Also changes in the treated effluent receiving streams after treated effluent outfall was discussed fully. The physico-chemical water quality of the receiving water bodies meets most of the general water requirements for both domestic and industrial uses. The untreated effluent quality was shown to be of biological origin based on the biological oxygen demand, chloride, dissolved oxygen, total solids, pH and organic matter. The treated effluent showed significant improvement over the raw untreated effluent based on most parameters assessed. There was a significant difference (p<0.05) between the physico-chemical quality of untreated effluent and the treated effluent for the most of the investigated physico-chemical quality. The difference between the discharged treated effluent and the unimpacted section of the receiving waterbodies was also significant (p<0.05) for the most of the physico-chemical parameters.

Raw dark fermentation effluent to support heterotrophic microalgae growth: microalgae successfully outcompete bacteria for acetate

ABSTRACT Coupling dark fermentation (DF), which produces hydrogen from diverse effluents or solid waste, and heterotrophic cultivation of microalgae, which produces lipids, carbohydrates and proteins, is a promising and innovative solution for developing sustainable biorefineries. The use of a raw DF effluent, containing acetate and butyrate, to support the heterotrophic growth of Chlorella sorokiniana was investigated. All the acetate in sterilized and unsterilized DF effluent was exhausted in less than three days of heterotrophic cultivation, whereas butyrate was not used by the microalgae. The microalgae biomass reached 0.33 g L− 1 with a carbon yield on acetate of 55%. The algal yield was higher than previously reported for synthetic DF effluent. It was concluded that compounds other than volatile fatty acids were present in the DF effluent and these could be consumed by the microalgae. After the acetate had been exhausted, butyrate was consumed by facultative and strict aerobic bacteria originating from the DF effluent. The concentration of the bacterial community increased during the experiment but did not have any significant impact on heterotrophic microalgae growth. A high microalgal biomass yield was achieved without requiring the DF effluent to be sterilized.

Integration of nanofiltration and reverse osmosis for metal separation and sulfuric acid recovery from gold mining effluent

Abstract This work assessed the viability of implementing sequential stages of microfiltration (MF), nanofiltration (NF) and reverse osmosis (RO) to recover sulfuric acid, separate noble metals, and produce high quality reuse water from a gold mining effluent, specifically from a pressure-oxidation process effluent. Additionally, lime demand for neutralization of the proposed treatment streams and current lime demand were compared. It was observed that the NF attained high sulfuric acid permeation, equivalent to 82%, and a substantial acid purification of approximately 77% in relation to feed solution. Moreover, the RO increased the acid content by 99% in relation to feed solution considering a recovery rate of 50%. The final RO permeate had low conductivity and reduced content of total solids and contaminants, thus showing promising potential for industrial reuse. Furthermore, the acid recovery did not led to an important loss of metals of high commercial value which were present in the raw effluent since their retention in the concentrates of the MF and NF was above 95%. The neutralization of the MF and NF concentrates allowed for a 20% reduction in lime consumption in relation current demand.

Sorption and biodegradation of artificial sweeteners in activated sludge processes

There is limited information on the occurrence and removal of artificial sweeteners (ASs) in biological wastewater treatment plants, and in particular, the contribution of sorption and biodegradation to their removal. This study investigated the fate of ASs in both the aqueous and solid phases in a water reclamation plant (WRP). All the four targeted ASs, i.e. acesulfame (ACE), sucralose (SUC), cyclamate (CYC) and saccharine (SAC), were detected in both the aqueous and solid phases of raw influent and primary effluent samples. The concentrations of CYC and SAC in secondary effluent or MBR permeate were below their method detection limits. ACE and SUC were persistent throughout the WRP, whereas CYC and SAC were completely removed in biological treatment (>99%). Experimental results showed that sorption played a minor role in the elimination of the ASs due to the relatively low sorption coefficients (Kd), where Kd<500L/kg. In particular, the poor removal of ACE and SUC in the WRP may be attributed to their physiochemical properties (i.e. logKow<0 or logD<3.2) and chemical structures containing strong withdrawing electron functional groups in heterocyclic rings (i.e. chloride and sulfonate).

Necessity of meat-processing industry's wastewater treatment—a one-year trial in Serbia

The emission of untreated or insufficiently treated wastewater is very common in developing countries and consequently has harmful effects on the environment. The aim of this study was to analyse 24 physico-chemical parameters in raw wastewater and effluent after tertiary treatment (denitrification and disinfection) derived from meat-processing plants in Serbia during four sampling campaigns conducted for one year. The biochemical oxygen demand (BOD5) and chemical oxygen demand (COD) were measured at high concentrations up to 6,960 and 14,160 mg/L, respectively, indicating a large amount of uncollected blood, solubilized fat, urine and faeces in discharged wastewater. Required limits of emission in all samples according to the European and national legislation for most of the studied parameters were exceeded. According to the obtained results, there is an imperative need for pretreatment of wastewater from meat industry before discharging it into the sewer. The applied wastewater treatment improved the quality of water by reducing BOD5 and COD values to 97.97 and 98.08%, respectively, while phosphorus removal efficiency varied from 15.29 to 68.48%.

Effect of inorganic amendments for in situ stabilization of cadmium in contaminated soils and its phyto-availability to wheat and rice under rotation.

Cadmium (Cd) toxicity is a widespread problem in crops grown on contaminated soils, and little information is available on the role of inorganic amendments in Cd immobilization, uptake, and tolerance in crops especially under filed conditions. The effect of three amendments, monoammonium phosphate (MAP), gypsum, and elemental sulfur (S), on Cd immobilization in soil and uptake in wheat and rice plants, under rotation, were investigated under field conditions receiving raw city effluent since >20 years and contaminated with Cd. Three levels of each treatment, 0.2, 0.4, and 0.8% by weight, were applied at the start of the experiment, and wheat was sown in the field. After wheat harvesting, rice was sown in the same field without application of amendments. Both crops were harvested at physiological maturity, and data regarding grain yield, straw biomass, Cd concentrations, and uptake in grain and straw, and bioavailable Cd in soil and soil pH were recorded. Both MAP and gypsum application increased grain yield and biomass of wheat and rice, while S application did not increase the yield of both crops. MAP and gypsum amendments decreased gain and straw Cd concentrations and uptake in both crops, while S application increased Cd concentrations in these parts which were correlated with soil bioavailable Cd. We conclude that MAP and gypsum amendments could be used to decrease Cd uptake by plants receiving raw city effluents, and gypsum might be a better amendment for in situ immobilization of Cd due to its low cost and frequent availability.

Evaluation of performance of Planococcus sp. TRC1 an indigenous bacterial isolate monoculture as bioremediator for tannery effluent

An indigenous bacterial isolate Planococcus sp. TRC1 was found to tolerate Cr(VI) solution up to 500 mg/L concentration when grown in mineral salt media. Gene sequencing of the isolated strain using 16S rDNA technique and phylogenetic analysis confirmed that the species was 96% close to Planococcus maritimus (KP8). Studies on cell dynamics in batch bioreactor showed the maximum specific cell growth rate (μmax) to be 0.276 h−1. Removal of Cr(VI) was observed to be dependent on initial chromium concentration and the maximum removal of Cr(VI) (75 ± 3%) was obtained at 25 mg/L Cr(VI) solution for an incubation period of 72 h. Above this value, the removal of Cr(VI) was declined. Scanning electron microscope and Fourier transform infrared spectroscopic studies indicated that the Cr(VI) removal took place by the adsorption process on the cell outer membrane. It is observed that the adsorption process follows the Freundlich adsorption isotherm (R2 = 0.987). Planococcus sp. TRC1 reduced 80 ± 5% chemical oxygen demand (COD) of tannery effluent (COD 7,270 ± 45 mg O2/L) within 48 h of batch treatment. The elimination of cytotoxicity and genotoxicity imparted by the raw tannery effluent and Cr(VI) solution after bacterial treatment is an important observation which reflects the eco-friendly behavior of the Planococcus sp. TRC1 mediated tannery effluent and aqueous Cr(VI) solution treatment. The results revealed the applicability of Planococcus sp. TRC1 in both tannery waste and Cr(VI) reduction without affecting our environment.

Integrated System of Phytodepuration for Agroindustrial Wastewater: Three Different Case Studies

The effluents deriving from agricultural industries are sources of wastewater sensibly different from common civil wastewater treatment plants effluents, because they are characterized by significant amounts of nutrients and organic load. Agricultural industries require considerable water volumes for processing the farm products, in doing so generating huge volumes of wastewater, with high concentration of chemical oxygen demand (COD), nitrogen (N) and phosphorus (P). Advanced and low cost techniques for water depuration are required in such circumstances, as the use of Integrated System of Phytodepuration (ISP). In the present work, three different case studies (a dairy, a pig feedlot and a vinegar industry) are investigated: the performances of the ISPs were evaluated analyzing raw wastewaters and final effluents over a period ranging from 2 to 4 years. The results obtained show that the designed ISPs are characterized by a mean efficiency value higher than 85% for COD removal, 73% for N and 85% for P. Moreover, for the pig feedlot the ISP final effluent is characterized by a quality level not only suited for the release into surface waters but also for irrigation, while for the other two case studies is possible to release the final effluent in surface water.

An application of response surface methodology for optimizing coagulation process of raw industrial effluent using Cassia obtusifolia seed gum together with alum

Coagulation is effective, simple to operate, and widely used in treatment of industrial effluent. However, commonly used inorganic coagulants pose detrimental effects on human health and living organisms in long run, and generate large amount of toxic sludge. Thus, this study investigated the optimized use of Cassia obtusifolia alone or combination of alum with lower dosages in treatment of industrial effluent. In this study, raw pulp and paper mill effluent (PPME) was used as a model wastewater in confirming the potential use of C. obtusifolia seed gum as a plant-based coagulant or coagulant aid together with the alum. Response surface methodology (RSM) enabled the study of interactive effects between operating treatment conditions, and to determine the optimal treatment conditions. The analysis of variance results obtained in the present study reflected significant quadratic models and strong correlations between operating conditions and treatment performance. In addition, current findings suggested that the coagulation mechanisms using C. obtusifolia seed gum together with the alum were most likely based on adsorption with inter-particle bridging and charge neutralization. Floc characterization also showed distinctive results, indicating the presence of active functional groups and the thermal stability of floc formed using C. obtusifolia seed gum and alum. Using RSM, optimal dosages of 0.17 and 0.09g/L of C. obtusifolia seed gum and alum, respectively were required to achieve maximum total suspended solids and chemical oxygen demand removals (89.6 and 55.4%, respectively) under natural pH of raw PPME and slow-mixing time of 3.40min. By combining the use of both coagulants, coagulant dosages of C. obtusifolia seed gum and alum could be reduced up to 90.5 and 62.5%, respectively. The present study revealed C. obtusifolia seed gum could be used as a potential plant-based coagulant or coagulant aid in treatment of raw and complex industrial effluent together with reduced dosage of alum.