生物吸附研究进展

生物吸附法是目前处理含金属废水的一种较有效的方法,特别是对于低浓度废水的处理优势明显。生物吸附法处理废水亦可达到以废治废的目的。本文就生物吸附领域目前研究状况进行了概述,主要包括了生物吸附剂对金属离子的吸附作用,生物吸附机理以及固定化吸附的应用研究。     

生物吸附法处理含铀废水研究进展

生物吸附法处理含铀废水是新兴的研究领域。本文介绍了吸附铀的生物材料的来源以及影响吸附过程的各种因素，总结了生物吸附的机理、生物材料的改性和固定化、生物吸附的数学模型等方面的研究进展。     

黄孢原毛平革菌吸附Cd2+和Zn2+的研究

利用黑曲霉常用液体培养基对黄孢原毛平革菌进行扩大培养，得到的菌丝球用于吸附废水中的Cd^2＋和Zn^2＋。本研究考察了初始pH、吸附时间以及共存离子对P．chrysosporium菌丝球吸附Cd^2＋和Zn^2＋的影响。在相同的实验条件下，研究重金属溶液初始浓度对吸附的影响发现其吸附曲线呈L2型，对重金属终浓度以及吸附量进行线性转换，发现Langmuir和Freundlich吸附模型能较好的描述P．chrysosporium菌丝球对Cd^2＋和Zn^2＋的吸附。将P．chrysosporium吸附Zn^2＋和Cd^2＋前后的红外光谱图作比较，发现P．chrysosporium吸附Zn^2＋和Cd^2＋后的主要成分和结构保持完整，3302cm^-1叫峰位分别移动61cm^-1和94cm^-1。     

Effect of salinity on metal-complex dye biosorption by Rhizopus arrhizus

In this study the biosorption of Yellow RL, a metal-complex anionic dye, by dried Rhizopus arrhizus, a filamentous fungus, was investigated as a function of initial solution pH, initial dye concentration and initial salt (sodium chloride) concentration. The fungus exhibited the maximal dye uptake at pH 2 in the absence and in the presence of salt. Dye uptake increased with the dye concentration up to 1000 mg l^?1 and diminished considerably in the presence of increasing concentrations of salt up to 50 g l^?1. The fungus biosorbed 85.4 mg dye g^?1of dried biomass at 100 mg l^?1 initial dye concentration in the absence of salt. When 50 g l^?1 salt was added to the biosorption medium, this value dropped to 60.8 mg g^?1 resulting in 28.8% reduction in biosorption capacity. The Redlich–Peterson and Langmuir–Freundlich were the most suitable adsorption models for describing the biosorption equilibrium data of the dye both individually and in salt containing medium. The pseudo-second-order and saturation type kinetic models depicted the biosorption kinetics accurately for all cases studied. Equilibrium and kinetic constants varied with the level of salt were expressed as a function of salt concentration.     

有机物生物吸附研究进展

生物吸附是有效处理难降解有机物的技术之一。本文从生物吸附的概念、生物吸附过程、吸附剂的制备及再生、生物吸附影响因素等方面进行了综述，同时阐述了生物吸附有机物的技术研究进展和应用前景展望。     

染料废水脱色的物理化学处理技术

染料废水目前主要的脱色方法有吸附、混凝、氧化还原和生化法.活性炭吸附适用于低浓度的染料废水处理.聚硅硫酸铁混凝效果与Fe/SiO4摩尔比和pH值相关.氢氧化镁可有效去除印染废水中的直接红染料.有机絮凝剂往往需要和其它药剂复配.氧化法脱色率大,但成本高昂,且受染料废水的组成、氧化性及pH值影响.还原法药剂价格低廉,但还原降解产物具有毒性,必须经过二次处理.生物法成本较低,又受制于染料的生物降解性.因此发展多种手段联合应用已是当前染料废水处理的研究方向.     

Application of low-cost adsorbents for dye removal – A review

Dyes are an important class of pollutants, and can even be identified by the human eye. Disposal of dyes in precious water resources must be avoided, however, and for that various treatment technologies are in use. Among various methods adsorption occupies a prominent place in dye removal. The growing demand for efficient and low-cost treatment methods and the importance of adsorption has given rise to low-cost alternative adsorbents (LCAs). This review highlights and provides an overview of these LCAs comprising natural, industrial as well as synthetic materials/wastes and their application for dyes removal. In addition, various other methods used for dye removal from water and wastewater are also complied in brief. From a comprehensive literature review, it was found that some LCAs, in addition to having wide availability, have fast kinetics and appreciable adsorption capacities too. Advantages and disadvantages of adsorbents, favourable conditions for particular adsorbate–adsorbent systems, and adsorption capacities of various low-cost adsorbents and commercial activated carbons as available in the literature are presented. Conclusions have been drawn from the literature reviewed, and suggestions for future research are proposed.     

白腐真菌处理染料废水研究进展

本文针对染料废水处理中存在的问题，介绍了利用白腐真菌处理废水的一般机理及其优势。在此基础上。对该菌种在处理染料废水研究应用中的筛选与降解机理、主要工艺条件对处理效果的影响和反应器类型等方面的研究成果给予了分析与评述。     

Application of adaptive heuristic criticism control (AHCC) to dye wastewater

This paper presents an experimental application of AHCC to study the coagulation process of wastewater treatment in a dye plant. Also this study includes a series of tests in which an AHCC control was used for pH control. The performance results of the AHCC controller are compared with the results obtained by using a conventional proportional-integral-derivative (PID) algorithm. It is useful to compare PID with AHCC to illustrate the extreme range of the nonlinearity of the dye wastewater treatment process. Although the removal of pollutants from wastewater is similar with AHCC and PID, our results show excellent AHCC performance in the region where conventional PID control fails.     

生物吸附法处理水体中的重金属的现状与展望

对生物吸附法处理水体中的重金属进行了综述，得出微生物对重金属表现出良好的吸附性能，吸附机理比较复杂，与离子交换有密切关系，常用吸附等温线评价微生物对重金属的吸附能力。由于该研究历史比较短，生物吸附的工艺应用、机理分析、生物固定化等研究还不够深入，有待进一步的研究探索，使其应用于工业生产。     

茄子秸杆活性炭对染料废水的吸附性能研究

以茄子秸秆为原料,ZnCl2为活化剂制备粉末状活性炭,主要研究了活性炭对染料废水的吸附性能;以活性红X-3B和酸性蓝RL为模型染料,考察了染料初始浓度、pH值、活性炭投加量和吸附时间等对染料脱色率的影响。结果表明,染料初始浓度和活性炭投加量对染料脱色率影响较大。初始浓度为300mg／L时,活性炭的最佳投加量分别为1g／L和1．4g／L;在最佳工艺条件下,脱色率分别在93％和98％以上,COD去除率分别为94．5％和86．4％,出水水质达到国家一级《纺织染整工业水污染物排放标准》（GB 4287—1992）。     

壳聚糖吸附处理废水的研究进展

壳聚糖吸附处理废水的研究包括其对废水吸附性能和吸附机理的研究两个方面。壳聚糖表现出了良好的吸附废水中重金属离子、染料分子和其它易引起变异物质的能力;壳聚糖对金属离子和染料的吸附机理模型研究理论意义重大,它将进一步推动壳聚糖的实际工程应用。     

Electrocoagulation of blue reactive,red disperse and mixed dyes,and application in treating textile effluent

This study investigated the efficiency of electrocoagulation in removing color from synthetic and real textile wastewater. Two representative dye molecules were selected for the synthetic dye wastewater: a blue reactive dye (Reactive Blue 140) and a disperse dye (Disperse Red 1). The electrochemical technique showed satisfactory color removal efficiency and reliable performance in treating both individual and mixed dye types. The removal efficiency and energy consumption data showed that, for a given current density, iron was superior to aluminum in treating both the reactive dye and the disperse dye. With an initial dye concentration of 100 mg L^?1, the energy cost in achieving >95% color removal was on the order of 1 kWh m^?3 for both dyes. The effect of changing the initial pH of the samples on the removal efficiency and energy consumption was also studied. It was found that the design parameters used for the synthetic wastewater were less effective for treatment of real textile wastewater, with 1 in 5 tests on real wastewater failing.     

Response surface optimization of acid red 119 dye from simulated wastewater using Al based waterworks sludge and polyaluminium chloride as coagulant

In this research, the performance of Polyaluminium Chloride (PAC) and Polyaluminium Chloride sludge (PACS) as coagulants for acid red 119 (AR119) dye removal from aqueous solutions were compared. The sample of PACS was collected from "Baba Sheikh Ali" water treatment plant (Isfahan, Iran) where PAC is used as a coagulant in the coagulation/flocculation process. A response surface methodology was applied to evaluate the simple and combined effects of the operating variables including initial pH, coagulant dosage and initial dye concentration and to optimize the operating conditions of the treatment process. Results reveal that the optimal conditions for dye removal were initial pH 3.42, coagulant dosage of 4.55 g dried PACS/L and initial dye concentration of 140 mg/L for PACS, while the optimal initial pH, coagulant dosage and initial dye concentration for PAC were 3.8, 57 mg/L and 140 mg/L, respectively. Under these optimal values of process parameters, the dye removal efficiency of 94.1% and 95.25% was observed for PACS and PAC, respectively. Although lower amount of PAC in comparison with PACS was needed for specific dye removal, the reuse of PACS as a low-cost material can offer some advantages such as high efficiency for AR119 dye removal and economic savings on overall water and wastewater treatment plant operation costs.     

Application of a chemically modified green macro alga as a biosorbent for phenol removal

Phenol and substituted phenols are toxic organic pollutants present in tannery waste streams. Environmental legislation defines the maximum discharge limit to be 5–50 ppm of total phenols in sewers. Thus the efforts to develop new efficient methods to remove phenolic compounds from wastewater are of primary concern. The present work aims at the use of a modified green macro alga (Caulerpa scalpelliformis) as a biosorbent for the removal of phenolic compounds from the post-tanning sectional stream. The effects of initial phenol concentration, contact time, temperature and initial pH of the solution on the biosorption potential of macro algal biomass have been investigated. Biosorption of phenol by modified green macro algae is best described by the Langmuir adsorption isotherm model. Biosorption kinetics of phenol onto modified green macro algal biomass were best described by a pseudo second order model. The maximum uptake capacity was found to be 20 mg of phenol per gram of green macro algae. A Boyd plot confirmed the external mass transfer as the slowest step involved in the biosorption process. The average effective diffusion coefficient was found to be 1.44 × 10⁻⁹ cm²/s. Thermodynamic studies confirmed the biosorption process to be exothermic.     

Treatment of Agro‐Based Industry Wastewater by the Electro‐Oxidation Method: Comparative Results From Iron and Aluminum Metal Plate

Among the various technologies available to treat wastewater from sugar production, electro‐oxidation, or electrocoagulation, is considered one of the best. Moreover, it is a cost‐effective method. Although it is considered an advanced form of chemical coagulation, it does not require the addition of chemical coagulants, as the coagulant is generated through the dissolution of the sacrificial anodes that are connected to the electric current in the treatment chamber. This article examines how an electro‐oxidation system can be established and explores the variables that affect the process.     

Biosorption of Cu and Zn from aqueous solutions by dried marine green macroalga Chaetomorpha linum

The biosorption of the heavy metals Cu²⁺ and Zn²⁺ by dried marine green macroalga (Chaetomorpha linum) was investigated. The biosorption capacities of the dried alga for copper and zinc were studied at different solution pH values (2–6), different algal particle sizes (100–800 μm) and different initial metal solution concentrations (0.5–10 mM). An optimum pH value of 5 was found suitable for both metal ions biosorption for both metal ions. At the optimum particle size (100–315 μm), biosorbent dosage (20 g/l) and initial solution pH (pH 5), the dried alga produced maximum copper and zinc uptakes values (q_max) of 1.46 and 1.97 mmol/g respectively (according to the Langmuir model). The kinetic data obtained at different initial metal concentrations indicated that the biosorption rate was fast and most of the process was completed within 120 min. This study illustrated an alternative technique for the management of unwanted biological materials using processed algal material. C. linum is one of the fast-growing marine algae in the lake of Tunis and could be utilized as a biosorbent for the treatment of Cu²⁺ and Zn²⁺ contaminated wastewater streams.     

Determination of optimum operating conditions for industrial dye wastewater treatment using adaptive heuristic criticism pH control

For a pilot-scale application, pH control in the treatment of highly contaminated dye industrial wastewater containing metallic compounds as the main pollutants has been investigated with a method using adaptive heuristic criticism control (AHCC). Subsequent experimentation on between 12 and 18 l of the wastewater was carried out using statistical experimental design methodology to evaluate the effects of three critical factors: slaked lime (calcium hydroxide, Ca(OH)(2)) concentration, iron chloride (FeCl(3)) concentration and wastewater volume. With these critical factors, the wastewater treatment process is modeled as an appropriate quadratic cost function of the turbidity of the clarified water. The model is optimized with Rosenbrock's method. Response surface topology of the wastewater treatment is given in terms of optimal concentrations of lime water and FeCl(3) and optimal wastewater volume at pH 11.     

Removal of the hazardous dye rhodamine B through photocatalytic and adsorption treatments

This paper reports on photocatalytic and adsorptive treatment of a hazardous xanthene dye, Rohdamine B, in wastewater. The photocatalytic degradation was carried out in the presence of the catalyst TiO(2) and the effects of pH, concentration of the dye, amount of TiO(2), temperature and electron acceptor H(2)O(2) on the degradation process were observed. It was found that photocatalytic degradation by TiO(2) is an effective, economical and faster mode of removing Rohdamine B from aqueous solutions. Attempts were also made to utilize activated carbon and rice husk as potential adsorbents to remove Rhodamine B from wastewater. The adsorption studies were carried out at 40, 50 and 60 degrees C, and the effects of pH, temperature, amount of adsorbents, concentration of adsorbate, etc., on the adsorption were measured. On the basis of adsorption data the Langmuir and Freundlich adsorption isotherm models were also confirmed. The adsorption isotherm constants thus obtained were employed to calculate thermodynamic parameters like Gibb's free energy, change in enthalpy and entropy. In order to observe the quality of wastewater COD measurements were also carried out before and after the treatments. A significant decrease in the COD values was observed, which clearly indicates that both photocatalytic and adsorption methods offer good potential to remove Rhodamine B from industrial effluents.     

Analysis of constraints and potentials for wastewater management in the coastal city of Manado, North Sulawesi, Indonesia

Manado is the largest and most densely populated coastal city in North Sulawesi Province, Indonesia. The city is facing problems of wastewater discharged from various sources. These problems are driven by high population pressure, increasing economic activity, and low household income, in combination with inadequate organizational structure of government institutions for addressing the wastewater problems as well as for law enforcement. There have been no community initiatives to prevent or mitigate wastewater problems. Therefore, a wastewater management plan is urgently needed to prevent and mitigate pollution caused by discharged wastewater. In this paper we analyze the current situation with respect to environmental state, sources and treatment of wastewater, socio-economic and institutional capacities as well as community awareness. Constraints and potentials are discussed to give recommendations for an integrated wastewater management plan for the city of Manado.