制革及毛皮加工项目污染治理措施建议

制革及毛皮加工行业具有排污量大、污水成分较复杂、企业环保意识不一、污染治理情况参差不齐、行业清洁生产推广力度较低等一系列问题。为有效控制制革及毛皮加工项目可能带来的环境影响,本文在查阅文献资料、进行数据分析和专家咨询、相关制革及毛皮加工项目实地调研的基础上,提出了制革及毛皮加工行业污染物治理措施建议。     

俄罗斯“爱克斯”皮革和毛皮废水处理技术

皮革和毛皮加工废水排放量大，污染物种类多，成份复杂，含量高，危害性大，直接排放到环境中将对自然环境造成严重污染和危害。这里介绍的俄罗斯水省设备厂研制的两种皮革和毛皮废水处理技术，可将皮革和毛皮加工厂废水处理达到循环利用，或达到农林业灌溉和水产养殖用水的水平。供国内同行参考借鉴，提高我国皮革和毛皮废水处理水平。     

环境保护部将推行皮革业更严厉排污标准

据悉,环境保护部将在明年对皮革产业加工环节实施更严厉的排污标准,占我国贸易顺差额近三成的皮革产品在产业升级道路上面临成本上升压力。在5月9日举行的＂中国毛皮行业环保政策宣贯会议暨毛皮产业可持续发展国际论坛＂上,环保部人士透露,针对皮革加工行业的水污染排放新标准将在2014年起实施。     

制革工业废水治理和综合利用

我国的制革厂一般规模小而分散,据1987年统计,全国约有制革厂500余家。制革生产过程中的准备、鞣制及其它湿加工工序要排出大量的废水,其废水中所含的污染物分有机物与无机物两类,有机物如蛋白质、油脂等;无机物有硫化物、三价铬、硫酸盐等。制革厂废水中含硫化物、三价铬和     

制革业铬鞣废水的治理研究

皮革加工是以动物皮为原料,经化学处理和机械加工而完成的.皮革加工过程中产生废水分为鞣前废水、鞣制废水、鞣后废水三部分.由于裸皮经铬鞣制后,皮革革身柔软丰满、细致、湿热稳定性好,因此铬盐作为鞣制剂被广泛运用于皮革生产中,研究表明皮革结合铬约占使用量77%,过多的铬则留在废铬液中被排放.铬鞣废波是制革废水的重要组成部分,其中含有大量Cr3 (40%),过多的铬如果不经处理就直接随废水排放,将对环境造成重大影响.本文通过查阅大量资料,对国内外目前常采用铬鞣废水治理方法进行综合叙述.     

制革废水的治理

制革废水不仅成份复杂,而且间歇排放,水质水量变化系数大,属于典型的高浓度有机废水。在各污染大户中,制革工业的污染危害仅次于造纸业而居第二位。废水来源主要是准备、鞣制两个生产阶段。生皮进厂首先进行浸水、脱毛工序,除去毛发、油脂等,操作大多在水溶液中进行。脱毛工序产生的废水主要含有氢氧化钙、硫化钠、硫氢化钠、角质、蛋白质、油脂、毛等,一般占总废水量的10％～15％;第二大工序是鞣制,是用铬盐使胶原稳定的工段,包括脱灰、浸酸、鞣制等,操作也在水溶液中进行。多数使用矿物鞣制硫酸铬和植物鞣制。铬鞣废水含有铬盐、硫酸钠等,其他各工序产生低浓度废水,废水污染物含量较低。对于这类废水的治理,目前在国际上还没有一套     

加强环保工作促进制革行业科学发展

我国皮革、毛皮及其制品行业有加工企业2万余家，其中制革企业2900多家、皮鞋企业9300多家、皮衣企业2200多家、皮具企业5900多家、毛皮及制品企业1200多家。“十五”期间，我国皮革工业保持了快速、稳定的增长。制革的污染问题是制约制革发展的关键，加强环保，污染防治、节能减排是制革科学发展的必由之路。     

2006~2009年工业COD和SO2减排分解研究

通过运用分解模型,将工业COD和工业SO2减排分解为规模效应、结构效应、清洁技术效应和污染治理效应,并根据模型测算了2006~2009年各种效应的大小.结果表明:规模效应值为58.68%,即经济规模扩张增加工业COD和工业SO2排放,结构效应、清洁技术效应和污染治理效应效应值分别为-0.63%、-49.34%和-29.79%,即促进工业COD和工业SO2减排;分行业来看,农副食品加工业和非金属矿物制品业发展迅速,需要严格控制其发展速度;化学纤维制造业的COD产生强度和电力、热力的生产和供应业、有色金属矿采选业、石油加工、炼焦及核燃料加工业的SO2产生强度升高,需要加强清洁生产控制;燃气生产和供应业、皮革毛皮羽毛(绒)及其制品业的COD去除率和非金属矿采选业、非金属矿物制品业和燃气生产和供应业的SO2去除率降低,需要加强污染治理控制.     

制革工业废水处理技术

一、制革工业的生产工艺及废水特性制革工业以动物皮(猪、牛、羊等)为原料,产品分轻革和重革两种.制革工业生产包括准备、鞣制和整理三道工序.前两道是湿法工序,最后一道是干加工工序.制革工业的废水从湿法工序中产生.准备工序包括浸水、浸灰、脱毛、膨胀,其目的是准备半制品,去除附着在原皮上的毛、蹄尾及血污、泥沙、防腐剂等.去除皮肉油脂及非纤维性蛋白质,使生皮的纤维结构适当分离和松散,便于鞣制和以后的整理.     

皮革和毛皮加工废水处理技术

采用混凝沉淀-酸化水解-悬挂链曝气-生物接触氧化组合工艺处理皮革和毛皮加工生产废水。实验结果表明;进水COD为2400mg/L,处理后出水COD≤100mg/L,去除率≥95.8%。各项水质指标均稳定地达到了GB8978-96污水综合排放一级标准。     

Cleaner tanning practices for tannery pollution abatement: Role of enzymes in eco-friendly vegetable tanning

Concern about pollution related problems in the global scenario are persuading all the processing industries to adopt cleaner manufacturing practices. Thus, the leather industry is also under pressure to look for effective alternative tanning materials for chromium. Natural products like vegetable tannins are regaining importance. However, there are limitations in the use of vegetable tanning materials because of its high organic load in the effluent, which are difficult to degrade leading to high chemical oxygen demand (COD). Moreover, conventional vegetable tanning process requires partial pickling that involves the use of sodium chloride, to suppress osmotic swelling. This results in very high amount of total dissolved solid (TDS) content in wastewaters. In this investigation, an attempt has been made to design an eco-friendly vegetable tanning process combining pickle-free tanning and application of proteolytic enzymes to improve the exhaustion of vegetable tannins. Such an approach has resulted in more than 95% tannin exhaustion in the case of the experimental process, an increase of 10% compared with the conventional vegetable tanning process. The tanned leathers showed slight improvement in hydrothermal stability. Physical and tactile evaluation of experimental leathers has been better than conventionally tanned leathers. Surface colour values illustrated negligible variation in colour and shade between control and experimental leathers. The resultant leather showed opened up, split compact fibre structure that has been well coated, indicating that the enzyme assisted tanning process did not bring about any major change or destruction on the fibre structure of the leathers. The optimized system has been field tested in a commercial tannery. The results showed that the enzyme assisted tanning process is efficient in terms of improved quality of leather and also led to reduction in total solids (TS), chlorides and COD loads. The enzyme assisted tanning system presented appears to be a viable option for combating pollution arising from the conventional vegetable tanning system.     

Studies on the use of power ultrasound in solid–liquid myrobalan extraction process

Focus on eco-friendly processing techniques makes vegetable tanning a viable option in leather processing and establishes the subsequent need for the more efficient methods of extraction in tannin manufacture. Application of ultrasound has been tried in the extraction of tannins from myrobalan nuts in order to improve the extraction efficiency, to perform the extraction under milder process conditions and to reduce the process time. The influence of process parameters such as ultrasonic output power, time and temperature has been studied. Scale-up trials and the use of ultrasound in pulse mode have also been attempted. The results show that a three- to fivefold improvement is possible with ultrasonic output from 20 to 100 W. Extraction efficiency has been calculated from the maximum extractable materials from myrobalan nuts. Extraction efficiency is found to be 90% for ultrasound, 100 W without external heating as compared to 77% for control process at 70 °C for 4 h. Therefore, ultrasound could be employed even dispensing with provision for temperature controls. The use of ultrasound in pulse mode offered 70% extraction efficiency of continuous mode. Scale-up trials indicate that there exists an optimum ultrasonic output power depending on the amount of nuts used, to achieve better extraction efficiency. The effectiveness of ultrasonically extracted tannin solution has also been tested in the tanning process for its applicability. The degree of tanning efficacy has been assessed by shrinkage temperature measurement. The results indicate that ultrasonically extracted tannin solution is suitable for tanning process. Therefore, application of ultrasound in tannin extract manufacture is a viable option with added advantages.     

An improved product-process for cleaner chrome tanning in leather processing

Severe restrictions imposed by the pollution control authorities on the disposal of chromium, total dissolved solids and chlorides in tannery effluents have forced the tanners to look for low-waste, high exhaust chrome tanning salts. An improved chrome syntan with more than 90% uptake of chrome has been developed. The new product serves both as tanning and retanning agent and can be applied directly to delimed pelts thus eliminating the conventional pickling stage in the leather processing. This modified process helps to reduce the chemical oxygen demand (COD), total dissolved solids (TDS) and chlorides in the spent tan liquor by 51, 81 and 99%, respectively. The product offers full, soft leathers having shrinkage temperature comparable to conventional chrome tanned skins. Since the developed product is highly reactive, it saves time and reduces the water requirement when compared to the conventional chrome tanning method. Thus the novel product/process developed not only has advantages in reducing pollution loads but also seems to be techno-economically viable.     

A chemo-enzymatic pathway leads towards zero discharge tanning

Leather processing has been an important industrial activity, which has gained significant economic relevance in India. The recent practices of leather manufacture cause difficulties with regard to environmental challenges. The conventional method for making the skins ready for tanning and the tanning by itself employs a wide variety of chemicals which result in an increase in chemical oxygen demand (COD), total dissolved solids (TDS), chlorides, sulfates and chromium in the tannery effluent. In this study, an integrated chemo-enzymatic methodology has been explored which would minimize or to some extent eradicate the unsafe chemicals involved in the process to provide a clean environment. The sequence involves an enzymatic dehairing, NaOH based fibre opening and a pickle-less chrome tanning. The modified process results in decrease in COD and TS (total solids) loads by 67 and 78%, respectively, as compared with control process. The process explored appears to be economically viable.     

基于鞣制工艺参数的铬污泥产污系数核算方法

针对无明确化学计量关系、均相或非均相封闭系统的一次性化工过程中产生的具有固定组成的污染物,其单位产品污染物产生量(即产污系数)的实测会因产品加工周期与污染物产出量相脱节而得不到准确值.制革行业铬鞣工段的诸多工艺参数对皮中铬的吸收率具有显著影响,通过实验室试验及历年工艺手册数据整理,在建立单一工艺参数与铬吸收率之间的关系基础上,采用逐步优化回归分析法,建立了鞣制工艺参数与铬污泥产生量之间的定量关系,并与企业实测铬污泥数据进行了对比.结果表明,通过工艺参数计算的铬污泥产污系数完全可以反映实际情况.      

Minimization of the environmental impact of chrome tanning: a new process reusing the tanning floats

A chrome tanning process which allows the reuse of tanning floats has been developed. The most commonly used chromium salts were replaced by highly masked and basified ones. This substitution eliminates basification operation and prevents pH change and the considerable neutral salts concentration increase in the tanning float. Consequently, tanning float can be reused several times. An optimum chromium salt concentration in the tanning float between 10% and 12.5% has been determined. It has been shown that the number of times the tanning float can be reused depends on the quality of the leather grain to be manufactured. In the best case, a saving of 18 L of water per kilogram of tanned leather is calculated. This means savings of 90% of water normally used.     

制革行业土壤铬污染特征及其影响因素

为了解制革场地土壤Cr(Ⅵ)污染情况和分布特征,选取我国3种典型制革企业用地的土壤和污泥样品,分析了制革行业土壤铬污染特征。结果表明:调查的Ⅰ型制革企业场地土壤Cr(Ⅵ)含量最高为48 mg/kg,超过GB 36600—2018《土壤环境质量建设用地土壤污染风险管控标准(试行)》筛选值,存在环境风险。调查的Ⅱ型制革企业环保设施完善,场地土壤Cr(Ⅵ)含量低于GB 36600—2018筛选值,土壤Cr(Ⅵ)环境风险低。Ⅱ型制革企业危险废物暂存间污泥总铬含量高达85377 mg/kg, Cr(Ⅵ)含量最高为1455 mg/kg。调查的Ⅲ型制革企业场地泥土混合物总铬含量为1564~28000 mg/kg, Cr(Ⅵ)含量最高为250 mg/kg,相较于Ⅰ型和Ⅱ型制革企业场地,受到严重污染。总体上,制革企业用地土壤铬污染物以Cr(Ⅲ)形态为主,Cr(Ⅵ)形态占比少,不足1%。     

SWOT分析模型在四川制革行业中的应用研究

文章在分析四川省制革行业发展现状的基础上,采用定性与定量结合的SWOT分析方法,分析了制革行业在四川省制革行业发展所面临的机会和威胁、所处的优势和劣势。结果表明,极坐标（ρ,θ）=（0．536,71．89°）处于坐标轴的第一象限,四川省制革行业应采取相对开拓的优势机会型战略,并据此提出相应具体战略措施。     

Recouping the wastewater: a way forward for cleaner leather processing

Leather processing employs copious amounts of water. This leads to the generation of enormous amounts of liquid effluent. The high effluent volume requires huge investments for effluent treatment plants in order to meet the required specification for the discharge of liquid effluents to various water bodies. Increasingly therefore, water use minimization in leather processing assumes greater significance due to increased treatment costs. End-of-pipe treatment methods alone do not meet the requirements and hence, in-plant control measures are gaining importance. The new era of cleaner technology has begun in leather processing. Pre-tanning and tanning operations contribute about 57% of the water consumption in leather processing and the washings about 35%. The proper adoption of integrated cleaner technologies provides a viable solution to the conservation of water in leather processing. This paper presents an integrated approach for water use minimization through recycling and optimization in leather processing. The integrated approach provides considerable reduction in the use of process water.     

改性羽毛处理铬鞣废水中Cr(Ⅲ)的研究

以甲基丙烯酸甲酯对羽毛进行接枝改性,以改性羽毛角蛋白处理铬鞣废水,探讨了铬鞣废水的处理量、铬鞣废水pH值、吸附时间等对铬离子吸附的影响,确定了最佳吸附条件:1.5g改性羽毛处理22mL铬鞣废水,铬鞣废水pH为4.5,静态吸附20h。