Evaluation of the Inverse Fluidized Bed Biological Reactor for Treating High-Strength Industrial Wastewaters

The aim of this work was to investigate the aerobic degradation of high-strength industrial (refinery) wastewaters in the inverse fluidized bed biological reactor, in which polypropylene particles of density 910 kg/m3 were fluidized by an upward flow of gas through a bed. Measurements of chemical oxygen demand (COD) versus residence time t were performed for various ratios of settled bed volume to reactor volume (Vb/VR) and air velocities u. The largest COD reduction, namely, from 54,840 to 2,190 mg/l, i.e. a 96% COD decrease, was achieved when the reactor was operated at the ratio (Vb/VR) = 0.55, air velocity u = 0.046 m/s and t = 65 h. Thus, these values of (Vb/VR), u and t can be considered as the optimal operating parameters for a reactor when used in treatment of high-strength refinery wastewaters. In the treatment operation conducted in a reactor optimally controlled at (Vb/VR) = 0.55, u = 0.046 m/s and t = 65 h, the conversions obtained for all phenolic constituents of the wastewater were larger than 95%. The conversions of about 90% were attained for other hydrocarbons.

Impact of industrial wastewater disposal on surface water bodies in Mostord area, North Greater Cairo

The studied area (Shoubra El Khima, Bahteem and Mostorod) lies in the industrial area north of Greater Cairo. The area suffers from several environmental problems such as sewage and disposal of pollutants from the surrounding factories into the surface water pathways in the area. Water samples were collected seasonally from different waterways found in the area, domestic and or industrial liquid wastes from 12 discharge tubes of different factories (as a point source of pollution). Chemical characteristics of different water samples and its heavy metals content were determined using ion coupled plasma technique (ICP). Results indicate that industrial and domestic wastewater samples contain several toxic levels of tested heavy metals (Cd, Co, Pb and Ni) which have a serious impact on surface waterways in the area. Shebin El Qanater collector drain samples exhibited the highest levels of Cd, Co, Pb and Ni compared to other tested water bodies. Mostorod collector drain samples showed the highest levels of Zn and Cu. Industrial effluent samples collected from Cairo Company for Fabric industry had the highest amounts of total Zn Cu, Cd, Co and Pb, while Delta steel company discharges the highest amounts of total Fe and Mn. Al Ahleya Plastic Company discharges the highest amounts of total Ni. Generally, it is necessary to impose the environmental laws and its regulation regarding the industrial wastewater treatments and disposals to minimize the risk of the adverse effects of these pollutants.

Outline and management of industrial wastewater in China

The essay covers the discharge and percentage of treatment of industrial wastewater in China before 1992,the analysis of industrial wastewater pollution to the environment and the problems and corrective measures to prevent and control the pollution caused by industrial wastewater in China.Water pollution is one of main environrnental problems in China. And industrial wastewater is a very important source to make water pollution. It is a key task to prevent industrial wastewater pollution and protect water quality of rivers, lakes (reservoirs), underground water in Chinese water environmental management.

A review of modified and hybrid anaerobic baffled reactors for industrial wastewater treatment

This review discusses high-strength wastewater treatment using anaerobic baffled reactors(ABRs)and modified ABRs.The research findings and applications of ABRs in treating various types of high strength wastewater generated from food companies,livestock,and industries were summarized and reported.Measurement parameters affecting the performance of ABRs are briefly discussed.The state-of-the-art laboratory studies are compiled and critically reviewed.Critical challenges and suggestions for future investigation are also addressed.

Rapid recovery of rare earth elements in industrial wastewater by CuFe_2O_4 synthesized from Cu sludge

This study systematically evaluates the recovery of rare earth elements（REEs） from aqueous solution and industrial wastewater using magnetic nanoparticles CuFe2O4. The industrially manufactured CuFe2O4 displays a nonlinear isotherm for REEs adsorption, suggesting limiting binding sites on the CuFe2O4 surface. The recovery of REEs increases significantly from 0.1% to 99.99% with increasing pH（2.29-8.15）. At room temperature, the maxima recovery rates of Nd, La, and Ce are observed to be in a high capacity of 51.02, 42.02, and 40.16 mg/g, respectively. No significant attenuation of REE adsorption is observed with increasing NaCl concentration from 0.001 to 1.0 mol/L, showing high selectivity of REEs even in such high NaCl concentration matrix. In addition, desorption efficiency increases with the increasing concentration of HNO3 in the range of 0.005-0.05 mol/L. When HNO3 concentration is over 0.05 mol/L, the desorption efficiency can reach almost 100% in each batch experiment. Importantly, our results show that REEs can be sorbed and recycled from liquid crystal display（LCD） polishing wastewater, suggesting that CuFe2O4 may be a good candidate in the efficient and rapid recovery of REEs from industrial wastewater.

Developments in Biological Treatment of Industrial Wastewaters

The characteristics and biological treatment technologies of several kinds of industrial wastewater are summarised. Biological treatment of industrial wastewater is a well established system with applications going back for over a century. However, developments are still taking place but at the design stage, more emphasis will be placed on small “footprint” systems, odour control and minimization of excess sludge production.

Highly selective and sensitive colorimetric chemosensor based on tricarboyanine for detection of Ag^(+) in industrial wastewater

An efficient fluorescent probe 1 based on tricarbocyanine derivative was designed and synthesized,which can detect Ag^(+) in real industrial wastewater.UV-V is absorption and fluorescent emission spectra of probe 1 were carried out and indicated this probe can bind Ag^(+) via complexation reaction,then leading to a remarkable color change from blue to light red.Furthermore,probe 1 showed high sensitive performance and excellent selectivity toward Ag^(+) over other common metal ions in neutral pH.The sensing mechanism was proposed and further confirmed by ^(1)H NMR,which demonstrate analyte-induced destruction of the π-electron system could be shorten by the disruption of the pull-push π-conjugation system in probe 1.Moreover,a test strip was prepared by filter paper immersing in probe 1 solution,which further provide its potential application for trace Ag^(+) detection in real industrial wastewater.

Study on Treatment Technologies of High Concentrations of Industrial Organic Wastewater

The characteristics and harm of high concentrations of organic wastewater were introducecl firstly, and then several treatment processes and effects of high concentrations of organic wastewater were summarized, which can provide theoretical references for the choice of wastewater treatment process.

On-Line Measurement of the Chemical Oxygen Demand in Wastewater in a Pulp and Paper Mill Using Near Infrared Spectroscopy

Although near infrared (NIR) spectroscopy has been evaluated for numerous applications, the number of actual on-line or even on-site industrial applications seems to be very limited. In the present paper, the attempts to produce online predictions of the chemical oxygen demand (COD) in wastewater from a pulp and paper mill using NIR spectroscopy are described. The task was perceived as very challenging, but with a root mean square error of prediction of 149 mg/l, roughly corresponding to 1/10 of the studied concentration interval, this attempt was deemed as successful. This result was obtained by using partial least squares model regression, interpolated reference values for calibration purposes, and by evenly distributing the calibration data in the concentration space. This work may also represent the first industrial application of online COD measurements in wastewater using NIR spectroscopy.

Removal Effect of Fluoride Ions by Aluminum Salt in Wastewater

To study a kind of high-efficiency fluoride removal agent based on aluminum salt,through theoretical and experimental research,the influence of different factors(dosage of agent,concentration of fluoride ions,pH,TDS,hardness and alkalinity,etc.)on the removal effect of fluoride ions by fluoride removal agent in industrial wastewater,especially mine water was analyzed.The results show that the fluoride ion removal agent based on aluminum salt could achieve efficient removal of fluoride ions,and the optimal mass ratio of fluoride ion concentration and compound reagent was 1∶130.The concentration of fluoride ions in the water produced after precipitation was≤1 mg/L under the optimal pH condition.As the pH of the solution was 6.5-7.5,the effect of fluoride removal by the agent was the highest.When the pH of the solution was>10.5 or<5,there was no effect of fluoride removal.Under the conditions of optimal pH and reagent dosage,the removal rate of fluoride ions rose with the increase of fluoride ion concentration in wastewater,up to 87.4%.It is also verified that TDS had no obvious effect on fluoride removal,and the smaller the hardness and alkalinity,the better the effect of fluoride removal.

Two-dimensional nanomaterials confined single atoms: New opportunities for environmental remediation

Two-dimensional(2D)supports confined single-atom catalysts(2D SACs)with unique geometric and electronic structures have been attractive candidates in different catalytic applications,such as energy conversion and storage,value-added chemical synthesis and environmental remediation.However,their environmental appli-cations lack of a comprehensive summary and in-depth discussion.In this review,recent progresses in synthesis routes and advanced characterization techniques for 2D SACs are introduced,and a comprehensive discussion on their applications in environmental remediation is presented.Generally,2D SACs can be effective in catalytic elimination of aqueous and gaseous pollutants via radical or non-radical routes and transformation of toxic pollutants into less poisonous species or highly value-added products,opening a new horizon for the contami-nant treatment.In addition,in-depth reaction mechanisms and potential pathways are systematically discussed,and the relationship between the structure-performance is highlighted.Finally,several critical challenges within this field are presented,and possible directions for further explorations of 2D SACs in environmental remediation are suggested.Although the research of 2D SACs in the environmental application is still in its infancy,this review will provide a timely summary on the emerging field,and would stimulate tremendous interest for designing more attractive 2D SACs and promoting their wide applications.

Study on the Recycling of P in Phosphogypsum Leachate

After washing and curing, P is transported from the phosphogypsum to the leachate during the phosphogypsum detoxification process, providing two ideas for phosphorus recovery from phosphogypsum leachate: 1) preparation of calcium hydrogen phosphate for feed;2) preparation of calcium phosphate. A ready-to-use calcium oxide slurry was used to recover P from phosphogypsum leachate at a slurry concentration of 20% and a quantitative link between calcium to phosphorus ratio and fixation rate was fitted by mixed use batch experiments, reaction kinetics and thermodynamics, and theoretical calculations were used to demonstrate that phosphorus cannot be completely reused in the preparation of calcium hydrogen phosphate. The findings demonstrated that: a) the residual phosphorus concentration was in the range of 1300 - 1500 mg/L for the preparation of type I feed grade calcium hydrogen phosphate from phosphogypsum leachate;b) the P removal effect could reach 99.99% for the preparation of calcium phosphate from phosphogypsum using the theoretical equation: fixation rate = 87.91 - 10.96(Ca/P) + 3.22(Ca/P)2 (R2 = 0.9954);c) The procedure follows the suggested secondary kinetics, and according to the Freundlich isothermal model, the reaction process is under the control of the chemical reaction, with a reaction index of 0.7605. This study can be used as a theoretical guide for the recovery of P from phosphogypsum leachate, the preparation of products to bring about economic by-products, and the purification of wastewater for reuse.

Natural marmatite photocatalyst for treatment of mineral processing wastewater to help zero wastewater discharge

Mineral processing wastewater(MPW)with large discharge and high toxicity affects environmental safety,and the realizing zero discharge of MPW is of great significance for reducing environmental pollution,saving water resources,and promoting the sustainable development of the mining industry.In this study,we reported natural marmatite(NM)as a low-cost and efficient photocatalyst for the treatment of MPW to help zero wastewater discharge.The photocatalytic activity of NM was evaluated by the removal of total organic carbon(TOC)from MPW under visible-light illumination,and the optimal degradation conditions were discussed.Results showed that superoxide free radicals(^(·)O_(2)^(-))were the dominant active species responsible for organic pollutants degradation,and 74.25%TOC removal was obtained after 120 min reaction under the optimum treatment conditions.Meanwhile,the wastewater treated by NM photocatalysis can be reused in the flotation system without adverse impact on the product index.Based on these findings,a model of zero wastewater discharge for flotation with the help of photocatalytic treatment was established,it indicated that the water of the whole system can be balanced without affecting the ore dressing index,which showed that visible light-driven photocatalyst has a promising application prospect in the treatment and recycling of industrial wastewater.

Review of MXenes as a component in smart textiles and an adsorbent for textile wastewater remediation

Two-dimensional(2D)MXenes have emerged as an archetypical layered material combining the properties of an organic-inorganic hybrid offering materials sustainability for a range of applications.Their surface functional groups and the associated chemical properties'tailorability through functionalizing MXenes with other materials as well as hydrophilicity and high conductivity enable them to be the best successor for various applications in textile industries,especially in the advancement of smart textiles and remediation of textile wastewater.MXene-based textile composite performs superb smartness in high-performance wearables as well as in the reduction of textile dyes from wastewater.This article critically reviews the significance of MXenes in two sectors of the textile industry.Firstly,we review the improvement of textile raw materials such as fiber,yarn,and fabric by using MXene as electrodes in supercapacitors,pressure sensors.Secondly,we review advancements in the removal of dyes from textile wastewater utilizing MXene as an absorbent by the adsorption process.MXene-based textiles demonstrated superior strength through the strong bonding between MXene and textile structures as well as the treatment of adsorbate by adsorbent(MXene in the adsorption process).We identify critical gaps for further research to enable their real-life applications.

Metal removal studied by a laboratory scale immobilized microalgal reactor

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Development of low-and non-waste technologies in China

Water pollution is one of the most serious environmental problems in China. In order to reduce the discharge of waste water per RMB 1000 Yuan of the industrial output value, the author offered a proposal on the development of low-and non-waste technologies as follows: 1. Changing distribution and structures of industrial production; 2. Innovation in techniques and eliminating industrial wastewater in the process of manufacture; 3. Comprehensive utilization of wastes and wastewater; 4. Strengthening environmental management and supervision of industrial enterprises.

Carbon materials in electrocatalytic oxidation systems for the treatment of organic pollutants in wastewater:A review

Carbon materials are widely used as catalysts in electrocatalytic oxidative(EO)degradation of wastewater due to their large specific surface area and low cost.Carbon materials can also be used as catalyst carriers for EO reactions due to their ease of functionalization with other heteroatoms and metals/metal oxides.To improve the catalytic activity and current efficiency of carbon materials,modifying the structural and physicochemical properties of conventional carbon materials are common improvement method.This review briefly outlines the recent research progress of carbon materials in EO for organic pollutants degradation.It also discusses the modification strategies and corresponding electrocatalytic properties of various carbon materials(carbon nanomaterials and porous carbon materials),and explores the EO mechanism.Finally,some summaries of the remaining challenges and future developments of carbon materials in the field of electrocatalysis are given.

Coking wastewater treatment for industrial reuse purpose: Combining biological processes with ultrafiltration, nanofiltration and reverse osmosis

A full-scale plant using anaerobic, anoxic and oxic processes （A1/A2/O）, along with a pilot-scale membrane bioreactor （MBR）, nanofiltration （NF） and reverse osmosis （RO） integrated system developed by Shanghai Baosteel Chemical Co. Ltd., was investigated to treat coking wastewater for industrial reuse over a period of one year. The removals reached 82.5% （COD）, 89.6% （BOD）, 99.8% （ammonium nitrogen）, 99.9% （phenol）, 44.6% （total cyanide （T-CN））, 99.7% （thiocyanide （SCN-）） and 8.9% （fluoride）, during the A1/A2/O biological treatment stage, and all parameters were further reduced by over 96.0%, except for fluoride （86.4%）, in the final discharge effluent from the currently operating plant. The pilot-scale MBR process reduced the turbidity to less than 0.65 NTU, and most of the toxic organic compounds were degraded or intercepted by the A1/A2/O followed MBR processes. In addition, parameters including COD, T-CN, total nitrogen, fluoride, chloride ion, hardness and conductivity were significantly reduced by the NF-RO system to a level suitable for industrial reuse, with a total water production ratio of 70.7%. However, the concentrates from the NF and RO units were highly polluted and should be disposed of properly or further treated before being discharged.

Capability of phenol-degrading biofilm

The degradation rate of phenol-degrading biofilm was studied.The biofilm of the biofilm was a kind of phenol-degrading bacteria.The bacteria was separated from coal chemical industry wastewater.The carbon source adopted four kinds of phenols,including phenol,methyl phenol,2-methyl phenol and resorcinol.Stenotrophomonas maltophilia K279a was gained.Twelve ratio of artificial phenol mixture was designed.The degradation rate of the twelve groups was all 99.9% in 16 h.The degradation rate from high to low was phenol,resorcinol,methyl phenol,2-methyl phenol.Phenol improved the degradation of the other phenols.The coal chemical wastewater contained 980 mg/L COD and 805 mg/L phenol.The degradation rate of COD and phenol was 70% and 77%,respectively.The domesticated biofilm (D) and the biofilm without domestication (WD) respectively used 45 h and 56 h.The results showed that the biofilm can be applied to the aerobic treatment process with high proportion of total phenol.