锰渣-赤泥吸附剂制备及其对铜（Ⅱ）吸附性能

锰渣是锰矿石生产硫酸锰过程产生的酸性过滤渣,赤泥是拜耳法生产氧化铝过程产生的碱性废渣,两种废渣排放量大,综合利用程度低。以锰渣和赤泥为原料,混合焙烧制备锰渣-赤泥吸附剂,实现了两种废渣的中和,制得的吸附剂pH接近中性。研究了锰渣-赤泥吸附剂对溶液中2价铜离子的吸附性能,为废渣的综合利用提供新途径。考察了吸附时间、溶液初始铜离子质量浓度、溶液pH等条件对吸附剂吸附溶液中铜离子的影响。结果表明：不同焙烧温度制得的吸附剂对铜离子的吸附平衡时间为22 h;焙烧温度为700 ℃制得的吸附剂（A700）对铜离子的吸附效果最好,在固液质量体积比（g/L）为0.4∶1条件下,达到平衡时溶液中铜离子的质量浓度可从20 mg/L降低到0.053 mg/L,平衡吸附量为45.739 2 mg/g,对铜离子的吸附去除率达到99.72%。吸附剂A700对铜离子的吸附符合准一级动力学模型和Langmuir等温吸附模型。     

铝基锂吸附剂制备及其吸附性能研究

以氯化锂、无水氯化铝为原料,通过正交实验优化反应合成条件,采用“一步法”制备LiCl·2Al（OH）₃·nH₂O型铝基锂吸附剂。分别探究了吸附时间、吸附温度、溶液初始pH、溶液初始Li⁺浓度对吸附性能的影响,对吸附前后的无机铝吸附材料做了表征,并考察了吸附剂的离子选择吸附性及稳定性能。结果表明：最佳吸附条件为在45 ℃下pH=7的锂溶液中吸附2 h,吸附容量高达到8.66 mg/g。XRD、FT-IR表征结果表明：所制吸附材料有良好的稳定性。且该吸附剂对Li⁺分配系数（K=10.06）远高于其他金属阳离子,吸附材料经5次循环使用后,吸附容量仍能保持原来的91.5%。在西藏龙木错盐湖卤水中,对锂的吸附量达到5.24 mg/g。吸附平衡数据拟合结果表明：铝基锂吸附剂符合Langmuir等温吸附模型,吸附是发生在吸附剂表面的单层吸附;吸附过程符合伪二级动力学,是典型的化学吸附过程。     

牛血清白蛋白纳米球接枝杨梅单宁的制备以及吸附去除水体中Pb2+的性能

采用去溶剂法和杨梅单宁-戊二醛固化接枝制备得到杨梅单宁（BT）接枝牛血清白蛋白（BSA）纳米球（BSA-BT-NSs）吸附材料，并系统探讨了其在不同吸附条件下对水体中Pb²⁺的吸附去除性能。研究结果表明：50%用量杨梅单宁（基于BSA-NSs量）接枝固化得到的BSA-BT-NSs具有较好的球形结构和良好的分散性。在吸附实验中，Pb²⁺初始浓度为250mg/L、pH 5.0、温度为298K 条件下吸附20min，BSA-BT-NSs（0.4g/L）对Pb²⁺的吸附效果最佳，最大吸附容量为76mg/g，优于多数同类型吸附材料。BSA-BT-NSs对Pb²⁺吸附过程符合Langmuir方程和准二级吸附动力学模型，且吸附后的BSA-BT-NSs经0.1mol/L 硝酸进行解吸取得了92.04％的良好解吸效果，并可再次重复使用。进一步分析其Pb²⁺吸附机理，表明BSA-BT-NSs中的氨基氮原子、羟基和羧基氧原子作为电子供体参与了与Pb²⁺的空轨道发生配位作用。     

层迭灵芝子实体及其制备炭吸附Cd2+的研究

以大型真菌层迭灵芝（Ganoderma lobatum）子实体及制备炭作为吸附材料用于吸附Cd²⁺,研究了吸附剂用量、初始pH值、反应时间、初始Cd²⁺质量浓度对吸附的影响。结果表明,当Cd²⁺质量浓度为10 mg/L时,层迭灵芝子实体及制备炭吸附Cd²⁺的最佳条件为吸附剂用量0.2 g,pH值为7,吸附时间为480 min,在此条件下Cd²⁺最大去除率分别为94.50%和92.75%。子实体对Cd²⁺的吸附速率显著高于制备炭,但子实体和制备炭吸附Cd²⁺的吸附能力之间无显著差异。采用Langmuir和Freundlich等温吸附模型研究子实体和制备炭吸附Cd²⁺的过程,子实体对Cd²⁺的吸附过程符合Freundlich模型,而制备炭更符合Langmuir模型。吸附动力学研究表明子实体和制备炭对Cd²⁺的吸附过程均符合准二级动力学模型。     

氧化铈-二氧化硅介孔材料制备及对铜离子的吸附性能

采用共沉淀法和沉淀浸渍法制备了纳米氧化铈-二氧化硅（CeO₂-SiO₂）介孔材料吸附剂,主要考察了其对水中铜离子（Cu²⁺）的吸附行为。通过X射线衍射（XRD）、扫描电镜（SEM）和氮吸附（BET）等手段对合成的介孔材料进行了性能表征,并通过静态吸附实验分析了溶液pH、溶液初始金属离子质量浓度、吸附剂用量、吸附时间等条件对介孔材料吸附Cu²⁺性能的影响。结果表明：共沉淀法制备的纳米CeO₂-SiO₂介孔材料对Cu²⁺的去除效果较沉淀浸渍法要好;当溶液pH=7.0时CeO₂-SiO₂介孔材料对Cu²⁺的吸附效果最好,20 min时基本达到吸附平衡;溶液初始Cu²⁺浓度增大Cu²⁺去除率降低,Cu²⁺累计吸附量增大;随着吸附剂用量增加Cu²⁺去除率增大,当CeO₂-SiO₂吸附剂用量为0.15 g/L时对Cu²⁺的去除率趋于稳定;CeO₂-SiO₂吸附剂对不同金属离子吸附性能由大到小的顺序为Cu²⁺、Fe²⁺、Mn²⁺,该吸附过程均符合准二级动力学模型。     

碳羟基磷灰石/钾长石复合材料对镍的吸附性能研究

以钾长石为原料,用液相合成法制备碳羟基磷灰石/钾长石吸附剂（CHAK）去除水中的重金属镍,用静态吸附实验考察了CHAK添加量、溶液初始pH、吸附时间、镍初始浓度等因素对镍去除效果的影响,并结合动力学及热力学拟合探究吸附机理。结果表明：随着CHAK量的增加,对Ni ²⁺的去除率增加,但吸附量会降低;溶液pH=6时吸附效果达到最佳;吸附时间为10 h时吸附达到平衡;Ni ²⁺溶液的初始质量浓度为50~4 000 mg/L时,CHAK对Ni ²⁺的吸附量呈先增长后平稳趋势,饱和吸附量与原材料相比增大7.1倍。动力学及热力学拟合结果显示：准二级模型更符合描述该吸附行为。ΔH>0,表明该吸附过程为吸热反应,升温有利于吸附。ΔG<0,表明该反应能自发进行。     

氨基磺酸改性海藻酸钠的制备及对Fe3+的吸附

为有效防止尾矿坝化学堵塞可在排水设施上涂覆海藻酸钠基吸附材料。以海藻酸钠(SA)为基体, 高碘酸钠为氧化剂, 氨基磺酸为改性材料, 制备了一种吸附材料氨基磺酸改性海藻酸钠(MSA), 使用FT-IR、SEM对其进行表征, 并研究了MSA对Fe³⁺的吸附行为。研究结果表明: —NHSO₃H被成功引入到海藻酸二醛(ADA)上制得MSA; MSA吸附Fe³⁺后分子尺寸增大, 分子链空隙增大。MSA吸附Fe³⁺的较佳吸附条件为Fe³⁺初始质量浓度200 mg/L、Fe³⁺溶液pH值2、吸附时间240 min, 吸附温度25 ℃, 此时MSA对Fe³⁺的吸附量最大, 为151 mg/g。吸附过程符合准二级动力学模型和Langmuir吸附等温式, MSA对Fe³⁺的吸附是单分子层化学吸附; 吸附热力学分析表明吸附过程是一个自发的过程, 且温度升高不利于吸附反应的进行。     

Hydrothermal synthesis of zeolitic material from circulating fluidized bed combustion fly ash for the highly efficient removal of lead from aqueous solution

The utilization of coal fly ash derived from circulating fluidized bed combustion (CFBFA) still faces great challenges because of its unique characteristics. In this study, a zeolitic material with Na-P1 zeolite as the main phase was successfully synthesized via a hydrothermal method by using CFBFA as the raw material. The effects of hydrothermal temperature, time, and added CTAB amount on the characterizations of synthesized materials were investigated by XRD, SEM, and XPS. The properties of the optimal zeolitic material and its adsorption performance for Pb²⁺ in aqueous solution were evaluated. The influences of pH, initial concentration, dosage, and temperature on Pb²⁺ adsorption were also examined. Results revealed the following optimal parameters for the synthesis of zeolitic material:NaOH concentration of 2 mol·L^-1, solid-to-liquid ratio of 1:10 g·ml^-1, hydrothermal temperature of 110℃, hydrothermal time of 9 h, and CTAB amount of 1 g (per 100 ml solution). The adsorption capacities of the zeolitic material reached 329.67, 424.69, and 542.22 mg·g^-1 when the pH values of aqueous solution were 5, 6, and 7, respectively. The Pb²⁺removal efficiency can reach more than 99% in aqueous solution with the initial concentrations of 100-300 mg·L^-1 under pH 6 and suitable adsorbent dosage. The adsorption and kinetics of Pb²⁺ on the zeolitic material can be described by Langmuir isotherm and pseudo-second-order kinetic models, respectively. The ion exchange between Pb²⁺ and Na⁺ and chemisorption are the main adsorption mechanism. All these findings imply that the synthesis of low-cost adsorbent for Pb²⁺ removal from weak acid and neutral aqueous solution provides a highly effective method to utilize CFBFA.     

水泥浆粉去除废水中铅离子效果及行为研究

水泥浆粉含有可吸附重金属离子的成分,可作为吸附剂来处理重金属离子废水。本文利用硅酸盐水泥制备了不同水化龄期的水泥浆粉来处理含Pb²⁺废水,通过X射线衍射仪、同步热分析仪、电感耦合等离子体发射光谱仪等测试方法,研究了水泥浆粉龄期、浆粉用量、Pb²⁺浓度、pH值、温度、时间对Pb²⁺去除效果及吸附行为的影响。结果表明,水泥浆粉对废水中的Pb²⁺去除率普遍大于80%。在35 ℃、pH=2、吸附时间200 min时,0.04 g水灰比为0.50、水化龄期为60 d的水泥浆粉对初始浓度为700 mg/L的Pb²⁺溶液的Pb²⁺去除率为96.06%,吸附容量为336.22 mg/g。水泥浆粉对Pb²⁺的吸附热力学符合Freundlich吸附等温模型,吸附动力学符合拟一级动力学模型。     

Enhanced adsorptive removal of Cr(VI) in aqueous solution by polyethyleneimine modified palygorskite

Polyethyleneimine (PEI) modified palygorskite (Pal) was used for the adsorption of Cr(VI) in aqueous solution. The absorbent was characterized by Fourier transform infrared spectroscopy (FT-IR) and thermogravimetric analysis (TGA). Characterized results confirmed that the Pal has been successfully modified by PEI. The modification of PEI increased the Cr(VI) adsorption performance of the Pal by the adsorption combined reduction mechanism, and amino groups of the adsorbent play the main role in the enhanced Cr(VI) adsorption. The maximum adsorption capacity was 51.10 mg·g^-1 at pH 4.0 and 25 ℃. The adsorption kinetics of Cr(VI) on the adsorbent conforms to the Langmuir isotherm model. The maximum adsorption occurs at pH 3, and then the adsorption capacity of PEI-Pal was decreased with the increase of pH values. The adsorption kinetics of Cr(VI) on PEI-Pal was modeled with pseudo-second-order model. The addition of Cl^-, SO₄^2- and PO₄^3- reduced the Cr(VI) adsorption by competition with Cr(VI) for the active sites of PEI-Pal. The Cr(VI) saturated PEI-Pal can be regenerated in alkaline solution, and the adsorption capacity can still be maintained at 30.44 mg·g^-1 after 4 cycles. The results demonstrate that PEI-Pal can be used as a potential adsorbent of Cr(VI) in aqueous solutions.     

Single and competitive adsorption affinity of heavy metals toward peanut shell-derived biochar and its mechanisms in aqueous systems

Converting peanut shells into biochar by pyrolysis was considered an environmentally friendly and efficient method for agricultural solid waste disposal. The properties of peanut shell-derived biochar (PBC) under different temperature and its adsorption capacity of heavy metals were investigated. It was found that PBC400 exhibited the highest cumulative capability for heavy metals elimination in single solute because of its high specific surface area and rich functional groups. Furthermore, the competitive adsorption revealed that PBC had a substantial difference in adsorption affinity from diverse heavy metal ions, sorption capacity decreased as Pb²⁺ > Cu²⁺ > Cd²⁺ > Ni²⁺ > Zn²⁺, which was lower than in a single solute. The adsorption process using selected biochar was optimized with respect to pH, reaction time, adsorbent dose, and initial concentration of heavy metals. The kinetic data was well fitted with PSO model, and the Langmuir model was adopted for adsorption equilibrium data in both cases of single solutes and mixed solutes for all heavy metals, which indicated that the removal course was primarily explained by monolayer adsorption, and chemical adsorption occupied an important role. Therefore, peanut shells derived biochar could be a potential and green adsorbent for wastewater treatment.     

钢渣对Ni2+与Cu2+的竞争吸附研究

将转炉钢渣磨碎筛分,从钢渣投加量、吸附时间、酸性条件等方面探究其对水溶液中Ni²⁺的吸附性能及吸附机理,并讨论Cu²⁺对钢渣吸附Ni²⁺的影响。研究结果表明,100 mL浓度为50 mg·L^-1的Ni²⁺溶液,用200目(0.074 mm)0.15 g的钢渣处理30 min,Ni²⁺的吸附率为99.88%。钢渣吸附Ni²⁺的过程符合准二级动力学模型和Freundlich等温模型。钢渣吸附Cu²⁺与吸附Ni²⁺属于竞争吸附,且钢渣对Cu²⁺的吸附能力优于对Ni²⁺的吸附能力。钢渣吸附Ni²⁺的过程以化学吸附为主,伴随着物理吸附,且随着钢渣表层吸附位点的减少,钢渣对Ni²⁺的物理吸附作用会逐渐减弱。该研究对处理工业含Ni²⁺与Cu²⁺的废水具有一定的指导意义。     

氨基功能化铝麦羟硅钠石吸附Hg2+性能研究

以水热合成的铝麦羟硅钠石（简称AlMag）为基体,以氨丙基三乙氧基硅烷为功能化试剂,制备氨基功能化的新型吸附剂材料AlMag-NH₂,研究氨基改性过程对材料结构的影响及其对水溶液中Hg²⁺的吸附效果。表征结果显示,氨基官能团成功嫁接于AlMag基体上,功能化的AlMag-NH₂由初始的玫瑰花苞形貌变为片层状形貌,层间距和平均孔径增大,比表面积略微减小,pH_PZC升高。优化吸附实验条件,当溶液pH=5.0、吸附时间为360 min、Hg²⁺初始质量浓度为10 mg/L时,AlMag-NH₂的去除率达到88.82%,是相同条件下AlMag去除率的2.4倍。AlMag-NH₂的Hg²⁺饱和吸附量为20.62 mg/g,吸附过程符合准二级动力学和Langmuir模型,该过程主要为化学吸附。     

Recovery of lithium using H4Mn3.5Ti1.5O12/reduced graphene oxide/polyacrylamide composite hydrogel from brine by Ads-ESIX process

Powdery Li⁺-imprinted manganese oxides adsorbent was widely used to the recovery of Li⁺, but there are some difficulties, such as poor stability in acid solution, inconvenience of operation and separation. In this work, a useful hydrogel composite based H₄Mn_3.5Ti_1.5O₁₂/reduced graphene oxide/polyacrylamide (HMTO-rGO/PAM) was fabricated by thermal initiation method with promising stable, conductive and selective properties. The resulting materials were characterized by field emission scanning electron microscope, infrared absorption spectrum, X-ray diffraction, X-ray photoelectron spectroscopy and electrochemical techniques. The recovery of Li⁺ was investigated using HMTO-rGO/PAM from brine by a separated two-stage sorption statically and electrically switched ion exchange desorption process. The adsorption capacity of 51.5 mg·g^-1 could be achieved with an initial Li⁺ concentration of 200 mg·L^-1 in pH 10, at 45 ℃ for 12 h. Li⁺ ions could be quickly desorbed by cyclic voltammetry (CV) in pH 3, 0.1 mol·L^-1 HCl/NH₄Cl accompanying the exchange of Li⁺ and H⁺(NH₄⁺) and the transfer of LMTO-rGO/PAM to HMTO-rGO/PAM.     

聚苯乙烯接枝聚乙烯亚胺树脂合成及Cu2+吸附

将聚苯乙烯经氯乙酰化后与聚乙烯亚胺（PEI）反应合成了带有多胺结构的聚苯乙烯接枝PEI树脂PSACP，考察了溶剂、温度、物料比、反应时间等因素对接枝反应的影响，其中，N,N-二甲基甲酰胺为溶剂，物料比为6:1，50℃反应5h时制得的PSACP全交换容量达到5.21mmol/g。PSACP对水溶液中的Cu²⁺具有明显的吸附作用，吸附量受溶液温度、pH和Cu²⁺初始浓度影响，45℃下对pH=5.7、初始浓度为0.5mg/mL的Cu²⁺水溶液的平衡吸附量为2.42mmol/g，吸附符合Langmuir单分子层吸附，经过三次循环，吸附容量仍然较高。25℃下对Cu²⁺的动态吸附容量达到2.74mmol/g，Cu²⁺可经1mol/L HCl洗脱，脱附率为83.8%且无拖尾现象。     

木醋液改性羟基磷灰石对溶液中Cd2+的吸附特性

水体中存在Cd²⁺会危害人体健康,Cd²⁺污染的去除是一个需要解决的问题。以羟基磷灰石(HAP)和低成本的木醋液(WV)为原料,通过水浴搅拌制备了木醋液改性羟基磷灰石(WV-HAP),并将其应用于去除溶液中Cd²⁺的研究。利用XRD、FT-IR、SEM、BET对WV-HAP进行了表征,通过吸附试验探究溶液初始pH、初始离子浓度、接触时间和温度对WV-HAP对Cd²⁺吸附特性的影响。结果表明:在吸附剂添加量2 g/L、温度298 K、Cd²⁺初始浓度100 mg/L、pH=5、吸附时间4 h时,WV-HAP的平衡吸附容量为46.43 mg/g;WV-HAP对Cd²⁺的吸附过程符合Langmuir等温吸附模型和准二级动力学模型;热力学研究表明吸附过程是吸热的;通过对吸附Cd²⁺前后的WV-HAP进行表征,发现吸附机制主要是表面吸附、孔道吸附和离子交换。WV-HAP表现出优于HAP的对溶液中Cd²⁺的吸附能力,是一种潜在的Cd²⁺吸附材料。     

电纺zein-SLS纤维膜的制备及其离子吸附性能研究

选用玉米醇溶蛋白（zein）作为鞘层包裹材料、木质素磺酸钠（SLS）作为芯层强化材料，采用同轴电纺技术制备了可有效吸附重金属离子的zein-SLS纤维膜。优化了膜制备工艺条件，确定纺丝电压适宜为14 kV，芯鞘层进料速率比适宜为1∶1。TEM证实，SLS被成功包埋于zein纤维膜中，但其负载量、包埋率和流失率受溶液pH的影响。离子吸附测试结果表明，SLS的加入可强化zein纤维膜对三种金属离子Ni²⁺、Zn²⁺、Cd²⁺的吸附效果，其中对Zn²⁺吸附能力的强化效果最为显著，上述吸附过程符合准二级吸附动力学模型。同时，在酸性条件下，随着pH的上升，zein纤维膜对Ni²⁺、Zn²⁺、Cd²⁺的吸附能力逐渐提高。     

Adsorption of Pb, Cu and Cd in FDU-1 silica and FDU-1 silica modified with humic acid

Ordered mesoporous silica with cubic structure, type FDU-1, was synthesized under strong acid media using B-50-6600 poly(ethylene oxide)–poly(butilene oxide)–poly(ethylene oxide) triblock copolymer (EO₃₉BO₄₇EO₃₉) and tetraethyl orthosilicate (TEOS). Humic acid (HA) was modified to the synthesis process at a concentration of 1.5 mmol per gram of SiO₂. Thermogravimetry, small angle X-ray diffraction, nitrogen adsorption and high resolution transmission electron microscopy were used to characterize the samples. The pristine FDU-1 and FDU-1 with incorporated 1.5 mmol of HA were tested for adsorption of Pb²⁺, Cu²⁺ and Cd²⁺ in aqueous solution. Incorporation of humic acid into the FDU-1 silica afforded an adsorbent with strong affinity for Cd²⁺, Cu²⁺ and Pb²⁺ from single ion solutions. Adsorption of Cu²⁺ was significantly enhanced after incorporation of humic acid, a fact that can be explained by the formation of complexes with carboxylic and phenolic groups at low concentrations of the metal cation. The results demonstrated the potential applicability of FDU-1 with incorporated HA in the removal of low concentrations of heavy metal cations from aqueous solution, such as wastewaters, after usual precipitation of metal hydroxides in alkaline medium and proper pH conditioning in the range between 6 and 7.     

交联氧化铝-壳聚糖新杂化吸附剂的制备及去除废水中Cu(Ⅱ)(英文)

A novel biosorbent was developed by coating chitosan,a naturally and abundantly available biopolymer,on to activated alumina based on oil shale ash via crosslinking.The adsorbent was characterized by various techniques,such as Fourier transform infrared spectroscopy,scanning electron microscopy,thermogravimetric-differential thermal analysis,and X-ray photoelectron spectroscope.Batch isothermal equilibrium adsorption experiments were condcted to evaluate the adsorbent for the removal of Cu(Ⅱ) from wastewater.The effect of pH and agitation time on the adsorption capacity was also investigated,indicating that the optimum pH was 6.0.The equilibrium adsorp-tion data were correlated with Langmuir and Freundlich models.The maximum monolayer adsorption capacity of chitosan coated alumina sorbent as obtained from Langmuir adsorption isotherm was found to be 315.46 mg·g-1 for Cu(Ⅱ).The adsorbent loaded with Cu(Ⅱ) was readily regenerated using 0.1 mol?L?1 sodium hydroxide solution.All these indicated that chitosan coated alumina adsorbent not only have high adsorption activity,but also had good stability in the wastewater treatment process.     

Green synthesis of nickel nanoparticles using Ocimum sanctum and their application in dye and pollutant adsorption

Nickel nanoparticles as an eco-friendly adsorbent was biosynthesized using Ocimum sanctum leaf extract. The phys-iochemical properties of green synthesized nickel nanoparticles (NiGs) were characterized by UV–Vis spectroscopy (UV–Vis), Fourier Transform Infrared Spectroscopy (FTIR), X-ray diffraction (XRD), Scanning Electron Microscope (SEM) and Transmission Electron Microscope (TEM). NiGs were used as adsorbent for the removal of dyes such as crystal violet (CV), eosin Y (EY), orange I (OR) and anionic pol utant nitrate (NO3?), sulfate (SO42?) from aqueous solution. Adsorption capacity of NiGs was examined in batch modes at different pH, contact time, NiG dosage, initial dye and pol utant concentration. The adsorption process was pH dependent and the adsorption capacity increased with increase in contact time and with that of NiG dosage, whereas the adsorption capacity decreased at higher con-centrations of dyes and pol utants. Maximum percentage removal of dyes and pol utants were observed at 40, 20, 30, 10 and 10 mg·L?1 initial concentration of CV, EY, OR, NO3?and SO42?respectively. The maximum adsorption capacities in Langmuir isotherm were found to be 0.454, 0.615, 0.273, 0.795 and 0.645 mg·g?1 at pH 8, 3, 3, 7 and 7 for CV, EY, OR, NO3?and SO42?respectively. The higher coefficients of correlation in Langmuir isotherm sug-gested monolayer adsorption. The mean energies (E), 2.23, 3.53, 2.50, 5.00 and 3.16 kJ·mol?1 for CV, EY, OR, NO3?and SO42?respectively, calculated from the Dubinin–Radushkevich isotherm showed physical adsorption of adsor-bate onto NiGs. Adsorption kinetics data was better fitted to pseudo-second-order kinetics with R2 N 0.870 for al dyes and pol utants. NiGs were found to be an effective adsorbent for the removal of dyes and pol utants from aque-ous solution and can be applied to treat textile and tannery effluents.