mL Of Wastewater Research Articles

Recovery of SARS-CoV-2 from Wastewater Using Centrifugal Ultrafiltration.

The COVID-19 pandemic is a global crisis and continues to impact communities as the disease spreads. Clinical testing alone provides a snapshot of infected individuals but is costly and difficult to perform logistically across whole populations. The virus which causes COVID-19, SARS-CoV-2, is shed in human feces and urine and can be detected in human waste. SARS-CoV-2 can be shed in high concentrations (>107 genomic copies/mL) due to its ability to replicate in the gastrointestinal tract of humans through attachment to the angiotensin-converting enzyme 2 (ACE-2) receptors there. Monitoring wastewater for SARS-CoV-2, alongside clinical testing, can more accurately represent the spread of disease within a community. This protocol describes a reliable and efficacious method to recover SARS-CoV-2 in wastewater, quantify genomic RNA levels, and evaluate concentration fluctuations over time. Using this protocol, viral levels as low as 10 genomic copies/mL were successfully detected from 30 mL of wastewater in more than seven-hundred samples collected between August 2020 and March 2021. Through the adaptation of traditional enteric virus methods used in food safety research, targets have been reliably detected with no inhibition of detection (RT-qPCR) observed in any sample processed. This protocol is currently used for surveillance of wastewater systems across New Castle County, Delaware.

Biomass productivity of Chlorella vulgaris cultivated in fish and dairy cattle wastewaters

The biomass productivity and nutrient composition of microalgae, such as Chlorella vulgaris, depend on the cultivation process and the nutrient content of growth media. Thus, in this study aimed to investigate the biomass productivity of C. vulgaris cultivated in fish and dairy cattle wastewaters. Thirty wastewater samples (2.5 L) were collected from system of production. Microalgae were cultivated in Erlenmeyer flasks containing 10 mL of microalgae and 1,790 mL of wastewater under constant light of 5,000 lux for 16 days at 25 ± 2.0 °C. Wastewater samples differed in composition. Biomass productivity was 47 % higher (P<0.0001) in dairy cattle than in fish wastewater, reaching 67.61 g m?3 day?1 (dry matter basis, DM) when compared by Student’s t-test (P<0.05). Cultivation media also had an effect on biomass chemical composition. The C. vulgaris grown in dairy cattle wastewater was higher in crude protein and ash contents (359.6 g kg?1 DM and 230.4 g kg?1 DM, respectively), whereas microalgae grown in fish wastewater had higher nitrogen-free extract content (347.8 g kg?1 DM). Crude fat content did not vary greatly (mean of 313.15 g kg?1 DM). The pH (8.0 – 8.7) and ammonia concentration (0.07 to 0.4 mg L?1) in fish wastewater was stable throughout the 16-day experimental period. In dairy wastewater, pH increased up (6.3 to 8.9) to the fourth day and remained constant thereafter, and ammonia concentration increased up (24.3 to 28.7 mg L?1) to the eighth day and then it declined (2.1 mg L?1). The C. vulgaris was successfully grown in both wastewaters, but productivity was higher in dairy cattle wastewater.

Effectiveness of Moringa Oleifera and Blends of Both Alum and Moringa as Coagulant in the Treatment of Dairy Wastewater

Food processing industries can cause some serious problems for the environment through the discharge of wastewater. There is little information on the effectiveness of Moringa Oleifera (MO)seeds on the treatment of dairy wastewater, this study therefore evaluated the effectiveness of MO seeds and blends of both alum and MO in the coagulation of diary wastewater. Wastewater collected from oriental food industry limited was kept in a 10L capacity plastic container covered using a black polyethene bag containing ice blocks and conveyed to the laboratory where it was kept in a refrigerator. Six different beakers (Nos 0-5) were filled with 200 mL of wastewater and different doses of the selected coagulant (alum, MO and a blend of both) was added to the six beakers ranging from 0-10mL at an increment of 2mL to treat the wastewater. The beaker with number 0 served as the control (no dosage) and this whole process was applied to both coagulants. This test was carried out at a settling time of 1 hour. The physicochemical characteristics of the treated dairy wastewater were determined using the standard methods. Data were analyzed using descriptive statistics and ANOVA. The analysis indicated that the raw wastewater had values of 932 NTU, 1690.99 mg/L, 7.2 and 685 mg/L for turbidity, BOD, pH and TSS respectively. The results revealed that at an optimum dosage and settling time of 10mL and 1hr respectively, the TSS removal efficiencies of 88.76, 82.63 and 86.42 % were obtained for blend of moringa and alum, alum and moringa respectively. The three types of coagulants did not have much effects on the BOD and there were no significant differences in the values. The use of the blend of moringa and alum is effective in the treatment of dairy wastewater.

Modeling energy requirements for a biogas-supported decentralized Water treatment systems for communities in chambishi (Zambia) and diepsloot (South Africa) townships

An analytical model to determine energy requirements for a Biogas-supported Decentralized Water Treatment Systems was carried out based on energy consumption in Zambia and energy produced during water reclamation from wastewater in South Africa.For Zambia, the power consumption of the pumps for water abstraction, suction, distribution and treatment was the basis for determining energy required per hour. This energy was provided by biogas which was produced from a mixed feedstock of equal proportions made up of food leftovers, sewage sludge and fecal matter. This energy and amount of feedstock were used to design the biodigester. The model determined that a 1400 m3 biodigester with biogas output of 8.6 ML/day could yield 57 kW electricity. These results compare proportionally very closely with those of the Safi Sana plant which has a 2500 m3 biodigester and produces 100 kW electricityFor South Africa, energy requirements were modeled using experimental data obtained from water reclamation of wastewater and using sludge residue to produce biogas for electricity. This experimental model determined that 618 ML/day of wastewater could be processed to yield power generation of 4.2 MW h, an upscale from the current 97 ML of wastewater per day that generates 1.1 MW h.

Chemical Treatment in Industrial Wastewater of Polyester Synthetic Fiber Made from Recycled Polyethylene Terephthalate Bottles: Minimize Environmental Impacts

The Polyester synthetic fiber (PSF) industry has recycled Polyethylene Terephthalate (PET) bottle into raw material and converted them into economically valuable textile materials. This study was aimed to provide an overview of wastewater treatment from PSF industry in minimizing its impact on the environment. The study of wastewater treatment from PSF industry has been carried out in chemical-physical treatment. The Jar Test experiment has been conducted with coagulant and flocculant addition into 1,000 mL of wastewater inside a 1 L beaker glass. Wastewater was treated with 3 coagulants and flocculant doses variation with range of PAC 175-225 mg/L and PE 0.25 mg / L. The results showed that the dose utilization of 200 mg/L of 5% Poly Aluminum Chloride (PAC) coagulant solution and 0.25 mg/L dose of 0.02% Poly Electrolyte (PE) flocculant solution could produce a treated wastewater that has complied with the effluent quality standards. The application of this optimum dose can reduce wastewater pollutants subtances of PSF industry which can minimize its impact on the environment.

SARS-CoV-2 RNA monitoring in wastewater as a potential early warning system for COVID-19 transmission in the community: A temporal case study

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the virus which causes coronavirus disease (COVID-19), has spread rapidly across the globe infecting millions of people and causing significant health and economic impacts. Authorities are exploring complimentary approaches to monitor this infectious disease at the community level. Wastewater-based epidemiology (WBE) approaches to detect SARS-CoV-2 RNA in municipal wastewater are being implemented worldwide as an environmental surveillance approach to inform health authority decision-making. Owing to the extended excretion of SARS-CoV-2 RNA in stool, WBE can surveil large populated areas with a longer detection window providing unique information on the presence of pre-symptomatic and asymptomatic cases that are unlikely to be screened by clinical testing. Herein, we analysed SARS-CoV-2 RNA in 24-h composite wastewater samples (n = 63) from three wastewater treatment plants (WWTPs) in Brisbane, Queensland, Australia from 24th of February to 1st of May 2020. A total of 21 samples were positive for SARS-CoV-2, ranging from 135 to 11,992 gene copies (GC)/100 mL of wastewater. Detections were made in a Southern Brisbane WWTP in late February 2020, up to three weeks before the first clininal case was reported there. Wastewater samples were generally positive during the period with highest caseload data. The positive SARS-CoV-2 RNA detection in wastewater while there were limited clinical reported cases demonstrates the potential of WBE as an early warning system to identify hotspots and target localised public health responses, such as increased individual testing and the provision of health warnings.

Remediation of Oil and Gas Sewage Effluents Using Physical Treatments


 
 
 
 The industrial effluents from the oil and gas industry contain harmful contaminants that bring detrimental effects to the aquatic life and human population. The primary concerns are the high value of Chemical Oxygen Demand (COD), Total Suspended Solids (TSS), turbidity and heavy metal content such as ferum and copper in the effluents, which did not comply with the Environmental Quality Act (1974) Industrial Effluent (Regulations) 2009 of Malaysian Department of Environment (DOE). This research aims to study the efficiency of natural bio-coagulants in treating the industrial effluent from the oil and gas industry. The industrial effluent sample was treated by using two natural biocoagulants F.A and F.B and three commercial treatment agents (bio-solvent, alum, and poly aluminium chloride (PAC)). Different beakers consisting of 7.5 wt% of each agent were added into 1.5 L of wastewater sample and left for a week without mechanical assistance. For the second stage, only F.A and alum were used during the experiment. By using five different weight percentages: 2.5%, 5.0%, 7.5%, 10.0%, and 12.5%, the treatment agents were added into 100 ml of wastewater and left for a week without any mechanical assistance. Then, the samples were analyzed for each of the five parameters. The results showed F.A is the best agent in COD treatment, with 41% reduction; followed by alum with 36%, PAC with 26% and bio-solvent with 22% reduction, respectively. The obtained results also showed that F.A and alum are at optimum performances at 7.5 wt%. The F.A and alum efficiency are deteriorating when the dosage is below and above 7.5 wt%.
 
 
 

Electrochemical Treatment of High Concentration Ammonia using RuO2/Ti Anode and TiO2 Nanotube Cathode

Objectives:In this study, the treatment potential of ammonia in wastewater generated by S company odor removal process was tested by using electrochemical reactor with RuO2/Ti anode and TiO2 nanotube cathode. The effect of chlorine ion concentration and current density on ammonia oxidation were investigated by comparing the treatment efficiencies.Methods:380 mL of wastewater was electrolyzed for 3 h using 4 anodes and 5 cathodes and pH, NH3-N, NO3--N, and TN were measured and analyzed every 30 minutes.Results and Discussion:As the addition of chlorine ion increases, about 1,700 mg/L of ammonia in the wastewater was found to increase in oxidation reaction rate due to an increase in chlorine based oxidizing agent. An increase in chlorine based oxidizing agent leads to an increase in indirect oxidation. As a result, total nitrogen removal was increased. Ammonia oxidation rate was increased as the current density increased. Nitrate, ammonia oxidation byproduct, was accumulated at a current density from 20 to 40 mA/cm2. At higher than 50 mA/cm2, nitrate was accumulated for a while and then decreased. Total nitrogen removal rate increased as the current density increased. During electrochemical oxidation of ammonia to nitrate, hydroxyl ions were consumed by the reaction. The hydroxyl ion consumed during ammonia oxidation was less than that produced from nitrate reduction.Conclusions:Thus, ammonia in actual wastewater was completely removed using RuO2/Ti anode and TiO2 nanotube cathode and the possibility of reducing nitrate was confirmed. We confirmed the applicability of the two electrodes to the real industry.

Fish Feed Formulation with the Addition of Sludge of Dairy Wastewater and Fermented Wheat Bran

HighlightColloids in dairy wastewater could be destabilized by adding ferric chlorideAspergillus niger could increase protein and decreased the crude fiber in wheat branWheat bran fermentation could be carried out in room temperature during three daysFish feed formulation was conducted by solving simultaneous linear equationsSludge of dairy wastewater and fermented wheat bran could be utilized as fish feedAbstractDairy wastewater contains suspended solids, which are very difficult to settle naturally. This waste could be treated by using ferric chloride, due to its ability to bind suspended solid and to form brown solid of Iron (III) hydroxide. The optimal amount of FeCl3 in coagulating dairy wastewater was 0.15 g of FeCl3 for every 250 mL of wastewater. This sludge could be utilized into something useful for the organism. The sludge of dairy wastewater could be mixed with other ingredients to make fish feed. Wheat bran, one of the ingredients used to make fish feed, was fermented using Aspergillus niger to increase the crude protein content and to lower crude fiber content. The addition of fermented wheat bran in fish feed formulation could increase the crude protein content in feed B (which had 0.085% iron) by 5.78% and feed C (which had 1.703% iron) by 5.17%. By using simultaneous linear equations, fish feed formulation was conducted by adding sludge of dairy wastewater, fermented wheat bran, rebon flour, starch, and vitamin C. In this research, two variations of fish feeds were made (feed B and feed C). The results indicated that feed B and feed C had better stability and buoyancy than feed A, as the commercial feed. Feed C also had the biggest crude protein of all feeds, amounting to 32.057%. Feed C also gave the best result in increasing nile tilapia’s growth rate. The result showed that sludge of dairy wastewater and fermented wheat bran could be added to fish feed formulation.

Mineralization of mefenamic acid from hospital wastewater using electro‐Fenton degradation: Optimization and identification of removal mechanism issues

AbstractMefenamic acid (MFA) is a nonsteroidal anti‐inflammatory drug widely used for the short‐term treatment of mild to moderate pain as well as treatment of primary dysmenorrhea and for decreasing the pain and blood loss during menstrual periods. Since MFA has been detected in raw and sewage water worldwide, the current work deals with the optimizing of removal of MFA from hospital wastewater using the electro‐Fenton (E‐Fenton) process. A cylindrical Pyrex reactor containing 250 ml of wastewater was employed for treatment investigation. The effects of main variables on the removal process were investigated and the optimum experimental condition was obtained with adequate desirability under the response surface methodology. The obtained results revealed that the removal efficiency of 95.3% was achieved under the optimal experimental condition, including MFA initial concentration of 7.0 mg L−1, the H2O2 dosage of 700 μl/L, the current density of 6.6 mA cm−2, and the reaction time of 12 min. The removal mechanism studies showed that •OH as the dominant radical species plays the main role in E‐Fenton process. The MFA removal followed the pseudo‐first‐order kinetic model. Under the optimum condition of the E‐Fenton process, the removal efficiency of MFA from synthetic wastewater was in satisfactory agreement with the real hospital wastewater treatment.

Treatment of hydroxyquinone-containing wastewater using precipitation method with barium salt

Hydroxyquinone compounds, such as 1,4-dihydroxyanthraquinone and alizarin sulfonate, are widely used in dye manufacturing, pharmaceutical manufacturing, and other industries. However, the treatment of hydroxyquinone-containing wastewater has seldom been examined. This study used a precipitation method with barium salt to treat nano-silver industrial wastewater. The results show that barium chloride was a suitable reagent for significantly degrading COD and color from nano-silver wastewater. When the initial pH value was 10.5, 8 g of BaCl2⋅2H2O were added to 100 mL of wastewater. After reaction at 15°C for 1 h, the removal efficiencies of COD and color in the nano-silver wastewater were 85.6% and 97.1%, respectively. Simulated wastewater containing sodium alizarin-3-sulfonate (ARS) or purpurin was used to further investigate the removal mechanism of hydroxyquinone compounds. Fourier transform infrared spectroscopy, X-ray diffraction, and some related experiments showed that hydroxyquinone compounds can directly react with barium ions in the solution so as to transfer from wastewater to precipitate. In addition, the newly produced barium sulfate particles have positive surface charges, which can improve the removal efficiency of hydroxyquinone compounds due to electrostatic attraction.

Biomethane Recovery from Fresh and Dry Water Hyacinth Anaerobic Co-Digestion with Pig Dung, Elephant Dung and Bat Dung with Different Alkali Pretreatments

Biomethane was produced from water hyacinth (Eichhornia crassipes (Mart.) Solms), an aquatic weed plant, comprising of cellulose, hemicellulose and lignin by using two steps of methods. The first was that fresh and dry water hyacinth in the length of 1 cm, were pretreated with 2 different alkali solutions; 2%(w/v) of NaOH and 10% (w/v) of Lime. The optimum condition was selected from 100, 120 and 140oC for 4 hr at ratio of 1g plant per 15 ml of treatment solution. The yields of sugar from NaOH pretreatments were higher than lime conditions. The highest of sugar yield at 60 g sugar /g substrate was observed from 140oC by using dry water hyacinth, whereas fresh hyacinth had yield at 36.7 g sugar /g substrate. The second method was 12 sets of anaerobic co-digestions with 3 types of dung; pig dung, elephant dung and bat dung, and 2 types plants; fresh and dry hyacinth that pretreated by sodium hydroxide and calcium hydroxide. The mixtures of sugar solution and treated plant solid from both hyacinths were used as substrates by using 200 ml of waste water from sweet corn industrial as starter. The co-digestions were achieved at 1:1 ratio of dung and mixture solutions and at 37±2°C under anaerobic condition for 45 days. The COD removal in rang of 51-69% were absorbed from all 12 conditions. The digestions from all lime treated plants showed higher methane concentration than NaOH treated plants. The lime treated fresh hyacinth had highest values of biochemical methane potential (BMP) and methane concentration were at 59.3% and 63.65 vol.%, respectively. They were equivalent to heating value at 12.58 MJ/m3. The second was lime treated dry hyacinth that showed 32.4% BMP and 43.15 vol.% of methane, respectively.

Nutrient Budgeting as an Approach to Assess and Manage the Impacts of Long-Term Irrigation Using Abattoir Wastewater

Disposal and management of abattoir wastewater have been a long-term concern in a high meat-consuming country like Australia. Land-based application of wastewater is considered to be the most economically viable disposal method and is widely used by abattoirs. In this study, we assessed the effects of long-term abattoir wastewater irrigation on soil physical and chemical characteristics of calcareous soils. Soil samples were collected from 16 different locations with seven 5 cm depths intervals down to 35 cm. Soil properties including soil type, bulk density, moisture holding capacity, pH, electrical conductivity (EC), nitrogen (N), phosphorus (P), carbon (C) and micronutrients were measured. Soil characteristics were compared with non-irrigated soils. The study area receives annually about 327 ML of wastewater with high concentration of N and P (186 and 30.4 mg/L). Overall, the site retained 0.6 t N/ha, 0.1 t P/ha and 0.4 t of K per hectare. Irrigation for over a decade onto the study site has caused a significant change in the soil fertility. Soil total N was increased by 82% compared to non-irrigated. Similarly, soil total P concentration was increased more than sixfold. The overall results showed that the abattoir wastewater irrigation to soil caused very significant changes in soil nutrient levels. These changes indicate need to recapture the surplus nutrient, in particular N, to avoid potential leaching and off-site effects.

LIQUID EXTRACTION CLEANING OF WASTEWATER OF EDIBLE OIL PRODUCTION

Ensuring of ecological plants safety where food products are produced as well as elimination of wastes influence upon the environment is our subject problem. Moreover it creates a significant environmental problem, as is the pollution of surface waters by organic substances. So that is why finding ways of industrial wastewater treatment is an urgent task. Our previous goal was the emulsions destruction, which are the main wastewater polluter component. Now our task is to continue further illuminated water purification method using liquid extraction. The methodology of experimental research is as follows: 50 ml of wastewater and 50 ml extractant (40 ml ethyl acetate (butyl acetate) and 10 ml of the appropriate alcohol) is mixed in the mixer for 30 minutes, then in the sump separated into two layers, extract and raffinate. The concentration of the contaminant in wastewater is determined by photocolorimetry analysis. To achieve the maximum degree of wastewater treatment we have chosen extractant, which has selective solubility with respect to pollutants. The authors have learnt that the increase in molar mass of alcohol leads to increasing the concentration of pollutants in the extract. From the list of studied alcohols, the most appropriate for using is butyl alcohol (butanol). Target component distribution between the liquid phases is defined by balance conditions. The authors have constructed line workers that allowed determining the transfer degrees number to the system using two types of extractants such as ethyl atсetat-butanol and butyl acetate – butanol. From the huge amount of liquid-extraction devices designs that can be recommended for oil wastewater treatment plants the most rational is mixing – extractors slop. As a research result suitable extractants are selected – a mixture of ethyl acetate and butyl acetate with butanol, the maximum alcohol content that provides heterogeneous region in the extraction system is defined as well. An operating line and equilibrium line and also transfer steps number are identified. The multistage extraction installation is the most appropriate and gives strong results for sewage treatment from oil production plants.

PEMANFAATAN KULIT JENGKOL SEBAGAI ADSORBEN DALAM PENYERAPAN LOGAM Cd (II) PADA LIMBAH CAIR INDUSTRI PELAPISAN LOGAM


 The aim of this research is to study the effect of activation processes to iodine number of ngapi nut peel adsorbent and to study the optimum adsorbent mass to reduce metallic Cadmium (Cd) concentration in electroplating wastewater. Ngapi nut peel was cleaned and mashed to a size of 100 mesh of sieve tray and then activated using nitric acid (HNO3) 4 N with specific ratio ngapi nut peel : nitric acid while heated at specific activation temperature and duration. Adsorbent dried in oven at specific temperature and duration of drying. Adsorbent with optimum iodine number then used in batch adsorption that carried out by using variations of mass in 50 mL of wastewater. The results showed that the optimum ratio of ngapi nut peel : nitric acid is 20:1 mg/mL at activation temperature 90°C, duration of activation 120 minutes, drying temperature 110 °C and duration of drying 120 minutes with iodine number 634.50 mg/g. The optimum mass of adsorbent is 1 g with capacity of adsorbent 1,326 mg/g.

PENENTUAN BILANGAN IODIN ADSORBEN KULIT JENGKOL DAN APLIKASINYA DALAM PENYERAPAN LOGAM Pb (II) PADA LIMBAH CAIR INDUSTRI PELAPISAN LOGAM


 The aim of this research is to study the effect of activation processes to iodine number of ngapi nut peel adsorbent and to study the optimum adsorbent mass to reduce metallic lead (Pb) concentration in electroplating wastewater. Ngapi nut peel was cleaned and mashed to a size of 100 mesh of sieve tray and then activated using nitric acid (HNO3) 4 N with specific ratio ngapi nut peel : nitric acid while heated at specific activation temperature and duration. Adsorbent dried in oven at specific temperature and duration of drying. Adsorbent with optimum iodine number then used in batch adsorption that carried out by using variations of mass in 50 mL of wastewater. The results showed that the optimum ratio of ngapi nut peel : nitric acid is 20:1 mg/mL at activation temperature 90°C, duration of activation 120 minutes, drying temperature 110 °C and duration of drying 120 minutes with iodine number 634.50 mg/g. The optimum mass of adsorbent is 1 g with percent of removal 69,19 %.

Simple determination of hydrazine in waste water by headspace solid-phase micro extraction and gas chromatography-tandem mass spectrometry after derivatization with trifluoro pentanedione

A headspace solid-phase micro extraction (HS-SPME) and gas chromatography-tandem mass spectrometric (GC-MS/MS) method is described to detect hydrazine after derivatization with 1,1,1-trifluoro-2,4-pentanedione (1,1,1-TFPD) to 3-methyl-5-(trifluoromethyl) pyrazole in industrial waste water. The following optimal HS-SPME conditions were used: 85 μm-carboxen-polydimethylsiloxane fibre, 100 mg L−1 TFPD, saturated NaCl, an extraction/derivatization temperature of 80 °C, a heating time of 40 min, and a pH of 9.5. Under the established conditions, the detection and quantification limits were 0.002 μg L−1 and 0.007 μg L−1 by using 5 mL of waste water and the intra- and inter-day relative standard deviations were less than 10.2% at concentrations of 0.02 and 0.1 μg L−1. The calibration curve showed good linearity, with r2 = 0.998; the accuracy was in the range of 98.0–103%; and the precision of the assay was less than 10.2% in industrial waste water. Hydrazine was detected over a concentration range of 0.011–0.074 μg L−1 in 5 of 20 waste water samples.

VISIBLE LIGHT SOLAR PHOTOCATALYTIC DEGRADATION OF PULP AND PAPER WASTEWATER USING DYE-SENSITISED TIO2

With the growing number of industries there are large volumes of wastewater generated every day. Pulp and paper mills are highly polluting as they release effluents containing organic pollutants, and high levels of Biological Oxygen Demand (BOD) and Chemical Oxygen Demand (COD). Even though well-established processes exist to treat these effluents, there are only a few processes which are energy efficient. Conventional treatment methods are not effective for the degradation of toxic organic pollutants, hence other treatment techniques are necessary. One of the recent developments in this field is the Advanced Oxidation Process (AOP). Solar photocatalysis is a type of AOP which utilises UV light to activate semiconductor photocatalyst in order to produce highly reactive radical species. TiO2 is a widely used catalyst for this purpose, to oxidise or reduce the organic pollutants in industrial wastewater. However, photocatalysis using visible light has been receiving increased attention hence, modification of TiO2 is necessary for its enhanced response to visible light. There are many methods for modifying TiO2, such as doping and photo-sensitisation. This study focusses on the modification of TiO2 using the method of dye-sensitisation (photo-sensitisation) with the dyes rhodamine B and methylene blue. Solar photocatalytic experiments were carried out for the degradation of pulp and paper wastewater, at different conditions like varying catalyst loading (500mg, 600mg, 750mg and 1000mg of catalyst for 300ml of aqueous wastewater) and effluent concentration (20ml, 25ml, 30ml and 35ml of wastewater). Preliminary tests were done to determine the best conditions for photocatalytic degradation, and these were applied for final tests

Utilization of Fertilizers for Improving The Process Rate of Organic Material Degradation in Anaerobic Reactor

This study aimed to assess utilization of fertilizers as nutrient in the anaerobic reactor. Nutrient is one important characteristic of waste for the treatment. Nutrient is required for the growth and reproduction process of microorganisms which involved in the anaerobic process. The wastewater used in this research is tofu wastewater. Gandasil B fertilizer has N 6 mg/l and P 20 mg/l. While for Gandasil D fertilizer has N 20 mg/l and P 15mg/l. Anaerobic reactor has 1000 ml of capacity which contain 600 ml of wastewater, 100 ml of liquid fertilizer, and 300 ml of space blank. Anerobic reactor observed for 14 days with 5 observed parameters. Those parameters are TSS, VSS, COD, N, and P. After 14 days, added of Gandasil B fertilizer decreased the concentration of TSS, VSS, COD, N, and P amounted to 57,56%, 26,84%, 80,08%, 96,75%, and 93,18%. compared to the 0th day. While the addition of Gandasil D fertilizer decreased the parameters amounted to 3,48%, 6,21%, 86,72%, 58,10%, and 90,78%. In conclusion, Gandasil B fertilizer in the anaerobic reactor improves the rate of organic material degradation more effectively than Gandasil D fertilizer. Keywords - Anaerobic reactor, COD, fertilizer, N, nutrient, P, TSS, VSS

Effects of wastewater irrigation on accumulation of heavy metals in soil and spinach; optimization by response surface methodology (RSM)

As a result of urbanization, urban wastewater has increased fast, so reusing urban wastewater has become a research topic for a long time. The goals of this study were effects of wastewater irrigation on accumulation of heavy metals in soil and spinach, and optimization by response surface methodology (RSM). The plants were transplanted into pots containing 7 kg of soil, and were irrigated with 400 mL of wastewater to water mixture (in different ratio) every day. The response surface methodology and central composite design have been used to clarify the experimental plan and determine the optimum settings of the independent variables and their responses. The independent factors were ratio of wastewater to water mixture (20, 40 and 60%; v/v) and different lengths of time for taking samples (10, 20 and 30 days). The results showed that the irrigation by wastewater led to accumulation of Mn and Ni in soil and plant. At the optimum time for taking samples (29.99 days) and ratio of wastewater to water mixture (59.85%; v/v) the maximum accumulation of Mn and Ni in soil,