Abstract: Contamination of water, due to the discharge of untreated industrial wastewaters into the ecosystem, has become a serious problem for many countries. In this study, bioadsorbents based on chitosan-g-poly(acrylamide) and montmorillonite (MMt) clay (CTS-g-PAAm/MMt) hydrogel nanocomposites were prepared via free‐radical grafting copolymerization and crosslinking of acrylamide monomer (AAm) onto natural polysaccharide chitosan (CTS) as backbone, in presence of various contents of MMt clay as nanofiller. Then, they were hydrolyzed to obtain highly functionalized pH‐sensitive nanomaterials with uppermost swelling properties. Their structure characterization was conducted by X-Ray Diffraction (XRD) and Scanning Electron Microscopy (SEM) analyses. The adsorption performances of the developed nanohybrids were examined for removal of methylene blue (MB) cationic dye from aqueous solutions. The factors affecting the removal of MB, such as clay content, pH medium, adsorbent dose, initial dye concentration and temperature were explored. The adsorption process was found to be highly pH dependent. From adsorption kinetic results, the prepared adsorbents showed remarkable adsorption capacity and fast adsorption rate, mainly more than 88% of MB removal efficiency was reached after 50 min in 200 mg L-1 of dye solution. In addition, the incorporating of various content of clay has enhanced adsorption capacity of CTS-g-PAAm matrix from 1685 to a highest value of 1749 mg g-1 for the optimized nanocomposite containing 2 wt.% of MMt. The experimental kinetic data were well described by the pseudo-second-order model, while the equilibrium data were represented perfectly by Langmuir isotherm model. The maximum Langmuir equilibrium adsorption capacity (qm) was found to increase from 2173 mg g−1 until 2221 mg g−1 by adding 2 wt.% of clay nanofiller. Thermodynamic parameters revealed the spontaneous and endothermic nature of the process. In addition, the reusability study revealed that these bioadsorbents could be well regenerated with desorption efficiency overhead 87% and without any obvious decrease of removal efficiency as compared to starting ones even after four consecutive adsorption/desorption cycles, which exceeded 64%. These results suggest that the optimized nanocomposites are promising as low cost bioadsorbents.
Abstract: Graphite intercalation compound (GIC) has been demonstrated to be a useful, low capacity and rapid adsorbent for the removal of organic micropollutants from water. The high electrical conductivity and low capacity of the material lends itself to electrochemical regeneration. Following electrochemical regeneration, equilibrium loading under similar conditions is reported to exceed that achieved by the fresh adsorbent. This behavior is reported in terms of the regeneration efficiency being greater than 100%. In this work, surface analysis techniques are employed to investigate the material in three states: ‘Fresh’, ‘Loaded’ and ‘Regenerated’. ‘Fresh’ GIC is shown to exhibit a hydrogen and oxygen rich surface layer approximately 150 nm thick. ‘Loaded’ GIC shows a similar but slightly thicker surface layer (approximately 370 nm thick) and significant enhancement in the hydrogen and oxygen abundance extending beyond 600 nm from the surface. 'Regenerated’ GIC shows an oxygen rich layer, slightly thicker than the fresh case at approximately 220 nm while showing a very much lower hydrogen enrichment at the surface. Results demonstrate that while the electrochemical regeneration effectively removes the phenol model pollutant, it also oxidizes the exposed carbon surface. These results may have a significant impact on the estimation of adsorbent life.
Abstract: The study of microbial ecology and their function in anaerobic digestion processes are essential to control the biological processes. This is to know the symbiotic relationship between the microorganisms that are involved in the conversion of complex organic matter in the industrial wastewater to simple molecules. In this study, diversity and quantity of bacterial community in the granular sludge taken from the different compartments of a full-scale upflow anaerobic sludge blanket (UASB) reactor treating brewery wastewater was investigated using polymerase chain reaction (PCR) and real-time quantitative PCR (qPCR). The phylogenetic analysis showed three major eubacteria phyla that belong to Proteobacteria, Firmicutes and Chloroflexi in the full-scale UASB reactor, with different groups populating different compartment. The result of qPCR assay showed high amount of eubacteria with increase in concentration along the reactor’s compartment. This study extends our understanding on the diverse, topological distribution and shifts in concentration of microbial communities in the different compartments of a full-scale UASB reactor treating brewery wastewater. The colonization and the trophic interactions among these microbial populations in reducing and transforming complex organic matter within the UASB reactors were established.
Abstract: A continuous copper precipitation treatment (CCPT) system was conceived at Intel Chandler Site to serve as a first-of-kind (FOK) facility-scale waste copper (Cu), nickel (Ni), and manganese (Mn) co-precipitation facility. The process was designed to treat highly variable wastewater discharged from a substrate packaging research factory. The paper discusses metals co-precipitation induced by internal changes for manufacturing facilities that lack the capacity for hardware expansion due to real estate restrictions, aggressive schedules, or budgetary constraints. Herein, operating parameters such as pH and oxidation reduction potential (ORP) were examined to analyze the ability of the CCPT System to immobilize various waste metals. Additionally, influential factors such as influent concentrations and retention times were investigated to quantify the environmental variability against system performance. A total of 2,027 samples were analyzed and statistically evaluated to measure the performance of CCPT that was internally retrofitted for Mn abatement to meet environmental regulations. In order to enhance the consistency of the influent, a separate holding tank was cannibalized from another system to collect and slow-feed the segregated Mn wastewater from the factory into CCPT. As a result, the baseline influent Mn decreased from 17.2+18.7 mg1L-1 at pre-pilot to 5.15+8.11 mg1L-1 post-pilot (70.1% reduction). Likewise, the pre-trial and post-trial average influent Cu values to CCPT were 52.0+54.6 mg1L-1 and 33.9+12.7 mg1L-1, respectively (34.8% reduction). However, the raw Ni content of 0.97+0.39 mg1L-1 at pre-pilot increased to 1.06+0.17 mg1L-1 at post-pilot. The average Mn output declined from 10.9+11.7 mg1L-1 at pre-pilot to 0.44+1.33 mg1L-1 at post-pilot (96.0% reduction) as a result of the pH and ORP operating setpoint changes. In similar fashion, the output Cu quality improved from 1.60+5.38 mg1L-1 to 0.55+1.02 mg1L-1 (65.6% reduction) while the Ni output sustained a 50% enhancement during the pilot study (0.22+0.19 mg1L-1 reduced to 0.11+0.06 mg1L-1). pH and ORP were shown to be significantly instrumental to the precipitative versatility of the CCPT System.
Abstract: Phenol is a hazardous material found in many industrial wastewaters. Photocatalytic degradation and furthermore catalyst doping are promising techniques in purpose of effective phenol removal, which have been studied comprehensively in this decade. In this study, Fe, Cr codoped TiO2 were prepared by sol-gel method, and its photocatalytic activity was investigated through degradation of phenol under visible light. The catalyst was characterized by XRD, SEM, FT-IR, BET, and EDX. The results showed that nanoparticles possess anatase phase, and the average size of nanoparticles was about 21 nm. Also, photocatalyst has significant surface area. Effect of experimental parameters such as pH, irradiation time, pollutant concentration, and catalyst concentration were investigated by using Design-Expert® software. 98% of phenol degradation was achieved after 6h of irradiation.
Abstract: The tamarind based resin containing hydroxypropane sulphonic acid groups has been synthesized and their adsorption behavior for heavy metal ions has been investigated using batch and column experiments. The hydroxypropane sulphonic acid group has been incorporated onto tamarind by a modified Porath's method of functionalisation of polysaccharides. The tamarind hydroxypropane sulphonic acid (THPSA) resin can selectively remove of heavy metal ions, which are contained in industrial wastewater. The THPSA resin was characterized by FTIR and thermogravimetric analysis. The effects of various adsorption conditions, such as pH, treatment time and adsorbent dose were also investigated. The optimum adsorption condition was found at pH 6, 120 minutes of equilibrium time and 0.1 gram of resin dose. The orders of distribution coefficient values were determined.
Abstract: A huge of dark color palm oil mill effluent (POME) cannot pass the discharge standard. It has been identified as the major contributor to the pollution load into ground water. Here, lignin-degrading yeast isolated from a termite nest was tested to treat the POME. Its lignin-degrading and decolorizing ability was determined. The result illustrated that Galactomyces sp. was successfully grown in POME. The decolorizing test demonstrated that 40% of Galactomyces sp. could reduce the color of POME (50% v/v) about 74-75% in 5 days without nutrient supplement. The result suggested that G. reessii has a potential to apply for decolorizing the dark wastewater like POME and other industrial wastewaters.
Abstract: This study was performed to optimise the react time (RT) and study its effects on the removal rates of nitrogen compounds in a sequencing batch reactor (SBR) treating synthetic industrial wastewater. The results showed that increasing the RT from 4 h to 10, 16 and 22 h significantly improved the nitrogen compounds’ removal efficiency, it was increased from 69.5% to 95%, 75.7 to 97% and from 54.2 to 80.1% for NH3-N, NO3-N and NO2-N respectively. The results obtained from this study showed that the RT of 22 h was the optimum for nitrogen compounds removal efficiency.
Abstract: In this preliminary work, locally available husk of Cajanus cajan (commonly known in India as Tur or Arhar), a bio-waste, has been used in its physically treated and chemically activated form for the removal of binary Cu (II) and Zn(II) ions from the real waste water obtained from an electroplating industry in Bangalore, Karnataka, India and from laboratory prepared binary solutions having almost similar composition of the metal ions, for comparison. The real wastewater after filtration and dilution for five times was used for biosorption studies at the normal pH of the solutions at room temperature. Langmuir's binary model was used to calculate the metal uptake capacities of the biosorbents. It was observed that Cu(II) is more competitive than Zn(II) in biosorption. In individual metal biosorption, Cu(II) uptake was found to be more than that of the Zn(II) and a similar trend was observed in the binary metal biosorption from real wastewater and laboratory prepared solutions. FTIR analysis was carried out to identify the functional groups in the industrial wastewater and EDAX for the elemental analysis of the biosorbents after experiments.
Abstract: Worldwide, about two-thirds of industrial and domestic wastewater effluent is discharged without treatment, which can cause contamination and eutrophication of the water. In particular, for Mediterranean countries, irrigation with treated wastewater would mitigate the water stress and support the agricultural sector. Changing global weather patterns will make the situation worse, due to increased susceptibility to drought, which can cause major environmental, social, and economic problems. The study was carried out in open field in an intensive agricultural area of the Apulian region in Southern Italy where freshwater resources are often scarce. As well as providing a water resource, irrigation with treated wastewater represents a significant source of nutrients for soil–plant systems. However, the use of wastewater might have further effects on soil. This study thus investigated the long-term impact of irrigation with reclaimed agro-industrial wastewater on the chemical characteristics of the soil. Two crops (processing tomato and broccoli) were cultivated in succession in Stornarella (Foggia) over four years from 2012 to 2016 using two types of irrigation water: groundwater and tertiary treated agro-industrial wastewater that had undergone an activated sludge process, sedimentation filtration, and UV radiation. Chemical analyses were performed on the irrigation waters and soil samples. The treated wastewater was characterised by high levels of several chemical parameters including TSS, EC, COD, BOD5, Na+, Ca2+, Mg2+, NH4-N, PO4-P, K+, SAR and CaCO3, as compared with the groundwater. However, despite these higher levels, the mean content of several chemical parameters in the soil did not show relevant differences between the irrigation treatments, in terms of the chemical features of the soil.
Abstract: The textile industry produces high amount of colored effluent each year. The management or treatment of these discharges depends on the applied techniques. Adsorption is one of wastewater treatment techniques destined to treat this kind of pollution, and the performance and efficiency predominantly depend on the nature of the adsorbent used. Therefore, scientific research is directed towards the development of new materials using different physical and chemical treatments to improve their adsorption capacities. In the same perspective, we looked at the effect of the heat treatment on the effectiveness of diatomite, which is found in abundance in Algeria. The textile dye Orange Bezaktiv (SRL-150) which is used as organic pollutants in this study is provided by the textile company SOITEXHAM in Oran city (west Algeria). The effect of different physicochemical parameters on the adsorption of SRL-150 on natural and modified diatomite is studied, and the results of the kinetics and adsorption isotherms were modeled.
Abstract: Sludge originates from the process of treatment of wastewater. It is the byproduct of wastewater treatment containing concentrated heavy metals and poorly biodegradable trace organic compounds, as well as potentially pathogenic organisms (viruses, bacteria, etc.) which are usually difficult to treat or dispose of. China, like other countries, is no stranger to the challenges posed by increase of wastewater. Treatment and disposal of sludge has been a problem for most cities in China. However, this problem has been exacerbated by other issues such as lack of technology, funding, and other factors. Suitable methods for such climatic conditions are still unavailable for modern cities in China. Against this background, this paper seeks to describe the methods used for treatment and disposal of sludge from industries and suggest a suitable method for treatment and disposal in Chongqing/China. From the research conducted, it was discovered that the highest treatment rate of sludge in Chongqing was 10.08%. The industrial waste piping system is not separated from the domestic system. Considering the proliferation of industry and urbanization, there is a likelihood that the production of sludge in Chongqing will increase. If the sludge produced is not properly managed, this may lead to adverse health and environmental effects. Disposal costs and methods for Chongqing were also included in this paper’s analysis. Research showed that incineration is the most expensive method of sludge disposal in China/Chongqing. Subsequent research therefore considered optional alternatives such as composting. Composting represents a relatively cheap waste disposal method considering the vast population, current technology and economic conditions of Chongqing, as well as China at large.
Abstract: This study was carried out to investigate the adverse
effect of industrial wastewater on surface water quality in Gebeng
industrial estate, Pahang, Malaysia. Surface water was collected from
six sampling stations. Physicochemical parameters were
characterized based on in-situ and ex-situ analysis according to
standard methods by American Public Health Association (APHA).
Selected heavy metals were determined by using Inductively Coupled
Plasma Mass Spectrometry (ICP MS). The results revealed that the
concentration of heavy metals such as Pb, Cu, Cd, Cr and Hg were
high in samples. The results also showed that the value of Pb and Hg
were higher in the wet season in comparison to dry season.
According to Malaysia National Water Quality Standard (NWQS)
and Water Quality Index (WQI) all the sampling station were
categorized as class IV (highly polluted). The present study revealed
that the adverse effects of careless disposal of wastes and directly
discharge of effluents affected on surface water quality. Therefore,
the authorities should implement the laws to ensure the proper
practices of wastewater management for environmental sustainability
around the study area.
Abstract: The biodegradable family of polymers
polyhydroxyalkanoates is an interesting substitute for convectional
fossil-based plastics. However, the manufacturing and environmental
impacts associated with their production via intracellular bacterial
fermentation are strongly dependent on the raw material used and on
energy consumption during the extraction process, limiting their
potential for commercialization. Industrial wastewater is studied in
this paper as a promising alternative feedstock for waste valorization.
Based on results from laboratory and pilot-scale experiments, a
conceptual process design, techno-economic analysis and life cycle
assessment are developed for the large-scale production of the most
common type of polyhydroxyalkanoate, polyhydroxbutyrate.
Intracellular polyhydroxybutyrate is obtained via fermentation of
microbial community present in industrial wastewater and the
downstream processing is based on chemical digestion with
surfactant and hypochlorite. The economic potential and
environmental performance results help identifying bottlenecks and
best opportunities to scale-up the process prior to industrial
implementation. The outcome of this research indicates that the
fermentation of wastewater towards PHB presents advantages
compared to traditional PHAs production from sugars because the
null environmental burdens and financial costs of the raw material in
the bioplastic production process. Nevertheless, process optimization
is still required to compete with the petrochemicals counterparts.
Abstract: Anaerobic modeling is a useful tool to describe and
simulate the condition and behaviour of anaerobic treatment units for
better effluent quality and biogas generation. The present
investigation deals with the anaerobic treatment of brewery
wastewater with varying organic loads. The chemical oxygen demand
(COD) and total suspended solids (TSS) of the influent and effluent
of the bioreactor were determined at various retention times to
generate data for kinetic coefficients. The bio-kinetic coefficients in
the modified Stover–Kincannon kinetic and methane generation
models were determined to study the performance of anaerobic
digestion process. At steady-state, the determination of the kinetic
coefficient (K), the endogenous decay coefficient (Kd), the maximum
growth rate of microorganisms (μmax), the growth yield coefficient
(Y), ultimate methane yield (Bo), maximum utilization rate constant
Umax and the saturation constant (KB) in the model were calculated to
be 0.046 g/g COD, 0.083 (d¯¹), 0.117 (d-¹), 0.357 g/g, 0.516 (L
CH4/gCODadded), 18.51 (g/L/day) and 13.64 (g/L/day) respectively.
The outcome of this study will help in simulation of anaerobic model
to predict usable methane and good effluent quality during the
treatment of industrial wastewater. Thus, this will protect the
environment, conserve natural resources, saves time and reduce cost
incur by the industries for the discharge of untreated or partially
treated wastewater. It will also contribute to a sustainable long-term
clean development mechanism for the optimization of the methane
produced from anaerobic degradation of waste in a close system.
Abstract: The heavy metals pollution in water, sediments and fish of Lake Manzala affected form the disposal of wastewater, industrial and agricultural drainage water into the lake on the environmental situation. A pilot plant with an industrial discharge flow of 135L/h designed according to the activated sludge plant to simulate between the biological and chemical treatment with the addition of alum to the aeration tank with dosages of 100, 150, 200 and 250 mg/L. The industrial discharge had concentrations of Lead and BOD5 with an average range 1.22, 145mg/L respectively. That means the average Pb was high up to 25 times than the allowed permissible concentration. The optimization of the chemical-biological process using 200mg/L Alum dosage compared has improvement of Lead and BOD5 removal efficiency to 61.76% and 56% respectively.
Abstract: Textile industry processes are among the most environmentally unfriendly industrial processes; because, they produce color wastewater that is heavily polluted the environment. Therefore, textile industry wastewater has to be treated before being discharged into the environment. In this study, experiments were conducted for different process parameters like nutrient dosage and dilution ratio against the pH and contact time to remove COD and color in a textile industrial wastewater using aquatic macrophytes Lemna minor L. The experimental results showed that the maximum percentage reduction of COD and color in a textile industry wastewater by Lemna minor L. was obtained at an optimum nutrient dosage of 50g, dilution ratio of 8, pH of 8 and contact time of 4 days. Similarly, the results of validation experiments showed that the experiments were able to reproduce the obtained optimum process parameters. The maximum removal percentage of color in an aqueous solution (86.35%) is higher than the removal of color in a textile industry wastewater (82.85). Further, the first order kinetic model was fitted well with the experimental data of this present study. Finally, this study concluded that Lemna minor L. may be used for removing all types of parameters in any type of textile industry wastewater.
Abstract: Conventional coagulation, advance oxidation process (AOPs), and the combined process were evaluated and compared for its suitability to treat the stabilized cutting-oil wastewater. The 90% efficiency was obtained from the coagulation at Al2(SO4)3 dosage of 150 mg/L and pH 7. On the other hands, efficiencies of AOPs for 30 minutes oxidation time were 10% for acoustic oxidation, 12% for acoustic oxidation with hydrogen peroxide, 76% for Fenton, and 92% sono-Fenton processes. The highest efficiency for effective oil removal of AOPs required large amount of chemical. Therefore, AOPs were studied as a post-treatment after conventional separation process. The efficiency was considerable as the effluent COD can pass the standard required for industrial wastewater discharge with less chemical and energy consumption.
Abstract: The sonochemical decolorization and degradation of azo dye Methyl violet using Fenton-s reagent in the presence of a high-frequency acoustic field has been investigated. Dyeing and textile effluents are the major sources of azo dyes, and are most troublesome among industrial wastewaters, causing imbalance in the eco-system. The effect of various operating conditions (initial concentration of dye, liquid-phase temperature, ultrasonic power and frequency and process time) on sonochemical degradation was investigated. Conversion was found to increase with increase in initial concentration, temperature, power level and frequency. Both horntype and tank-type sonicators were used, at various power levels (250W, 400W and 500W) for frequencies ranging from 20 kHz - 1000 kHz. A 'Process Intensification' parameter PI, was defined to quantify the enhancement of the degradation reaction by ultrasound when compared to control (i.e., without ultrasound). The present work clearly demonstrates that a high-frequency ultrasonic bath can be used to achieve higher process throughput and energy efficiency at a larger scale of operation.
Abstract: The treatment of the industrial wastewater can be
particularly difficult in the presence of toxic compounds. Excessive
concentration of Chromium in soluble form is toxic to a wide variety
of living organisms. Biological removal of heavy metals using natural
and genetically engineered microorganisms has aroused great interest
because of its lower impact on the environment. Ralston
metallidurans, formerly known as Alcaligenes eutrophus is a LProteobacterium
colonizing industrial wastewater with a high content
of heavy metals. Tris-buffered mineral salt medium was used for
growing Alcaligenes eutrophus AE104 (pEBZ141). The cells were
cultivated for 18 h at 30 oC in Tris-buffered mineral salt medium
containing 3 mM disodium sulphate and 46 mM sodium gluconate as
the carbon source. The cells were harvested by centrifugation,
washed, and suspended in 10 mM Tris HCl, pH 7.0, containing 46
mM sodium gluconate, and 5 mM Chromium. Interaction among
induction of chr resistance determinant, and chromate reduction have
been demonstrated. Results of this study show that the above bacteria
can be very useful for bioremediation of chromium from industrial
wastewater.