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Adsorption offers an efficient, cost-effective, and eco-friendly method for the treatment of dye-laden wastewater. This work presents reactive red 198 (RR198) removal by adsorption using bentonite clay (BC) blended with sugar cane bagasse ash (SCBA). The adsorbent's surface morphologies, crystalline phase structures, functional groups, and specific surface before and after adsorption were examined using SEM, XRD, FTIR, and BET respectively. Central composite design (CCD) under response surface methodology (RSM) was applied to optimize independent and dependent variable values. The optimal parameters for RR198 removal using the blended adsorbent were 107 minutes contact time, 0.934 g/L adsorbent dose, and 15 mg/L initial dye concentration, and 85.2% RR198 removal efficiency was achieved. The sorption isotherms and kinetics were evaluated using various existing models. The Freundlich isotherm model (R2 = 0.95) and the pseudo-second-order equation best described the adsorption parameters and the RR198 adsorption kinetic mechanism, respectively. Desorption and reusability experiments in batch study confirmed that BC blended with SCBA can be used multiple times for dye removal from wastewater.

Ethiopia, albeit tagged as an underdeveloped nation, boasts astounding biodiversity, a vibrant culture, and the use of numerous traditional bio-techniques and processes. However, the adoption and a...

This study evaluated various industrial effluents’ effect on irrigation water quality and farm soil near Kombolcha town. Several industries such as brewery, steel iron, textile, and tannery have been installed near the Borkena River that crosses Kombolcha town. Representative samples of irrigation water and farm soil were collected from the upper and down part of Borkena river. The upper site was used as a control as it was not contaminated by industrial effluents. The analysis for selected parameters showed that the downstream irrigation water quality had mean concentrations of pH = 8.54, magnesium (Mg+2) = 5.27 mg/l, carbonate (CO3−2) = 1.25 mg/l, bicarbonate (HCO3−) = 9.10 mg/l, copper (Cu) = 0.21 mg/l, chromium (Cr) = 0.31 mg/l, and cadmium (Cd) = 0.03 mg/l which were above the permissible limit of the Food and Agriculture Organization’s (FAO’s) irrigation water quality standard. The mean concentrations of electric conductivity (EC) = 0.96 ds/m, sodium (Na+) = 3.35 mg/l, chloride (Cl−) = 7.67 mg/l, and total dissolved solids (TDS) = 612.98 mg/l were slightly and moderately restricted for irrigation. Moreover, the concentration of heavy metals, calcium (Ca+2) = 16.61 mg/l, iron (Fe) = 4.25 mg/l, manganese (Mn) = 0.18 mg/l, and lead (Pb) = 0.47 mg/l, was below the permissible limit of the FAO and nonrestricted. However, the mean concentration of EC, HCO3−, Cu, Cr, Cd, and TDS for downstream-irrigated farm soil samples was above the permissible limit of the FAO. The concentration of most selected parameters in downstream farm soil was also decreasing along with depth except pH, CO3−2, and HCO3-. Generally, there is a significant quality difference (at P ≤ 0.05) between the upstream and downstream irrigation water quality on the parameters of Mg+2, Cl−, Pb, and Cu.

Recently, the concentration of emerging contaminants is increasing in drinking water sources, industrial wastewater, and reclaimed water. It is not possible to remove the emerging contaminants using conventional methods, and the interest to use nanomembrane-based filtration is getting attention. A nanomembrane-based filtration can be manipulated without the use of any special equipment. Different research findings reported better removal of emerging contaminants has been achieved using nanomembrane-based filtration. Moreover, new developments have been examined and implemented at different levels and are expected to continue. Therefore, this chapter provides a brief overview of recent developments on nanomembrane-based filtration processes in the removal of emerging contaminants from drinking water sources, industrial wastewater, and reclaimed water.

The fate of filter materials and microbial communities during the vermifiltration process were studied for 5 months while treating the concentrated greywater. Four filters were filled with 10 cm gravel of which a layer of medium size gravel (5 cm thickness, aggregate size 20–40 mm) at the bottom and a layer of coarse gravel (5 cm thickness, aggregate size 10–20 mm) at the top, then filled with 20 cm sand (d60 = 0.2 mm, d10 = 0.118 mm). Finally, Vermifilter 1 (VF1), control unit and Vermifilter 2 (VF2), were filled with 40 cm fine sawdust (0.05–5 mm) but Vermifilter 3 (VF3), was filled with 40 cm cow dung (0.05–5 mm). Three filters were inoculated with 200 individuals of Eudrilus eugeniae except for the control unit which was filled with sawdust. Five sampling ports were installed on the wall of the filters at 10 cm intervals with reference to the surface of the top layer. Three of the filters were supplied with concentrated greywater and VF1 was supplied with drinking water at the hydraulic loading rate of 16 L m−2.d−1 on batch basis, i.e., four times a day at 8:00 a.m., 11:00 a.m., 2:00 p.m. and 5:00 p.m. Weekly, samples from influent and effluent, and monthly, samples of filter materials collected via sampling ports, were collected and analyzed.The removal efficiencies of biological oxygen demand (BOD5), total chemical oxygen demand (tCOD), and dissolved chemical oxygen demand (dCOD) of VF2 and VF3 were 5–7% higher than the control unit, but little differences were observed in terms of total suspended solids (TSS). However, the removal efficiencies of nutrients for the control unit was slightly better than VF2 and VF3. The pH and Moisture content (MC) of filter materials increased along the depth, but percentage of volatile solids to total solids (VS/TS) decreased through time due to the high number of microbial communities and earthworms dominating the top layer compared to the bottom. The performance of VF2-sawdust was slightly better than VF3-cow dung to treat concentrated greywater., Highlights • Fate of filter materials and microbial communities during vermifiltration process were studied. • Ratio of volatile solids to total solids decreased during vermifiltration process in filter materials. • The bacteria, actinomycetes and fungi intensified where earthworms dominated. • VF2-Sawdust performed slightly better than the VF3-Cow dung.

In this study, activated carbon was prepared from locally available bamboo (Arundinaria alpina) in Ethiopia to remove Pb (II) from wastewater. Various effects such as solution pH, initial Pb (II) ion concentration, and adsorbent dose were investigated and accordingly discussed, and the process was carried out on a batch adsorption base. Dried Arundinaria alpina stem was activated with potassium hydroxide (KOH) at a ratio of 1 : 1 (w/v) and carbonized in a furnace at three temperature ranges (500oC, 600oC, and 700oC) for 3 h. The physicochemical of Arundinaria alpina stem activated carbon (AASAC) was investigated and the resultant of 500oC treatment setup is found as ideal in terms of yield (40.6 g), ash (3.5%), porosity (0.704%), moisture (7.7%), and iodine number (814.69 mg/g). The further characterization of ideal AASAC was carried out by scanning electron microscopy (SEM), X-ray diffraction (XRD) spectroscopy, and Fourier transform infra-red (FTIR). The optimum Pb (II) removal efficiency of AASAC was 99.8% at pH 5 in a synthetic solution, but the efficiency declined to 60.42% on real industrial wastewater due to the presence of its mixed pollutant nature. Freundlich isotherm model is more favorable than Langmuir with a high correlation coefficient (R2-0.9496) for Pb (II) adsorption. The study revealed that AASAC has a potential adsorption efficiency to remove the Pb (II) ion from the aqueous solution which is also recommended as an adsorbent for real industry wastewater treatment.

Dyes and other chemicals laden wastewater is a main environmental concern for increasing the textile industries in many parts of the world. Textile industries consume different kinds of manmade dyes or other chemicals and release huge extents of highly polluted water into the environment. This excessive dye laden wastewater has great impacts on photosynthetic activity in aquatic plants and animals, for example, fish. It may also affect human health due to the presence of components like heavy metals and chlorine in manmade dyes. Thus, wastewater effluent from textile industries must be treated before discharge into the water body. Treatment technologies observed in this review paper include biological treatment methods (fungi, algae, bacteria, and microbial fuel cells), chemical treatment methods (photocatalytic oxidation, ozone, and Fenton’s process), and physicochemical treatment methods (adsorption, ion exchange, coagulation, and filtration). This review also includes the hybrid treatment methods and their cost per m3 of treated wastewater analysis. There are alternative wastewater treatments systems at different steps of effluent generated from the textile operational unit recommend in this review work.

Vermifiltration technology using Eudrilus Eugeniae could be an alternative low-cost option for the treatment of urban greywater, which is highly polluted with high concentrations of surfactants, so...

This study focused on the evaluation of Aloe steudneri gel for textile wastewater clarification with identification of major phytochemical groups and physicochemical characteristics of Aloe steudneri. Optimization of pH, flocculant dose, mixing speed and time were studied for Aloe steudneri gel and synthetic polyacrylamide. A jar test was used to perform the flocculation at optimum conditions (pH 7.3, flocculant dose 33 ml, mixing time 20 minutes and speed 61 rpm). Phytochemical groups like tannins, flavonoids and saponins were identified and the gel showed a good result of 1.9 g H2O/dry polymer for swelling capacity and 6.2 g oil/weight for fat adsorption capacity. At the optimum conditions, the turbidity removal was 92.3% for Aloe steudneri gel and 92.7% for polyacrylamide. Moreover, the removal efficiencies for chemical oxygen demand, 5-day biological oxygen demand, total suspended solids and lead were 76.8%, 83.5%, 57.9% and 77% for Aloe steudneri gel and 78%, 89%, 51% and 72% for polyacrylamide, respectively. Therefore, it is possible to conclude that Aloe steudneri gel can substitute the polyacrylamide as there are no significant differences in their removal efficiencies.

The treatment of greywater collected from an urban slum area of Ouagadougou, Burkina Faso, by vermifiltration (VF) was investigated using locally available sawdust as bedding material and Eudrilus eugeniae earthworm. The filtration system was made up of layers of sand, and fine and coarse gravel from the top to the bottom, which was spread inside a cylindrical DN200-PVC pipe. The fine sawdust and density of 6370 worms/m2 were added while the same filtration system without earthworms was used as an experimental control. Batch experiments were conducted at ambient temperature, with hydraulic loading rate of 64 and 191 L m−2 d−1. The raw greywater was highly concentrated with biochemical oxygen demand (BOD5) varying from 690 to 2200 mg/L and pH varying from 4.37 to 7.32. The results showed that Eudrilus eugeniae were able to tolerate temperatures above 40 °C and avoided odour and clogging problems inside the filter. The removal efficiencies of BOD5, chemical oxygen demand, total suspended solid, E. coli and thermotolerant coliforms were better in the vermifilter than in the control system. Moreover, the pH at the exit of the system was close to neutral. Therefore, VF could be applied as an alternative low-cost technology to treat greywater for the urban poor in hot climate areas.

A comparative investigation was conducted for 10 months with sand and fine sawdust vermifilters and a control unit to treat concentrated grey water generated from a poor urban household in Ouagadougou, Burkina Faso. Each of the filters was made up of cylindrical DN200-PVC pipes and filled with 10 cm of gravel at the bottom. On top of the gravel layer, filter 1 (fully sand, F1) was completed with 40 cm of sand and 10 cm of fine sawdust, filter 2 (partially sand, F2) with 20 cm of sand and 30 cm of fine sawdust, respectively, and filter 3 (fully sawdust, F3) and 4 (control, F4) with 50 cm of fine sawdust only. Two hundred Eudrilus eugeniae earthworms were inoculated in each of the vermifilters. The vermifiltration system was supplied with grey water four times per day at a hydraulic loading rate of 64 L/m(2)/day on a batch basis. The removal efficiencies of biological oxygen demand, total chemical oxygen demand, and dissolved chemical oxygen demand (dCOD) by the vermifilters were 25-30% higher than the control, but little differences were observed in terms of total suspended solids and coliform removal efficiencies. Though there was no significant difference in the performance of the three vermifilters (p 0.05), except for dCOD removal efficiency, the lifespan of F2 and F3 was longer than that of F1. Therefore, fine sawdust can substitute sand as a filter medium in vermifilters.