【摘要】：制革行業(yè)是我國輕工行業(yè)中的支柱產業(yè),同時也是污染較嚴重的行業(yè)。制革廢水因含有高濃度的蛋白質、脂肪,以及生產過程中加入的硫化鈉、鉻鞣劑、染料、無機鹽、石灰等化工原料使其成為較難處理的工業(yè)廢水。盡管自2011年3月1日實施的HJ2003-2010《制革及毛皮加工廢水治理工程技術規(guī)范》對制革廢水治理工程設計、施工、驗收和運行管理的技術要求提出明確規(guī)定,但2014年3月1日實施的GB30486-2013《制革及毛皮加工工業(yè)水污染物排放標準》,明確增加了制革廢水排放應重點控制的總氮等特征污染物項目指標,并收緊了排放限值和基準排水量指標,使制革行業(yè)環(huán)保治理水平的全面提升勢在必行。本課題以某年產85萬張真皮革企業(yè)2500m3/d制革廢水處理工程為實例,在掌握各類廢水污染特征、設計處理負荷與工藝設計參數(shù)等基礎上,通過現(xiàn)場調試闡明運行主要存在問題,擬定試驗方案,科學獲取各工藝處理單元真實因果關系,進而優(yōu)化構建各項水質指標全面穩(wěn)定達標排放完整的組合處理工藝,對規(guī)范制革廢水處理及實現(xiàn)行業(yè)可持續(xù)健康發(fā)展具有積極的現(xiàn)實意義。研究結果表明,廢水預處理是保證綜合廢水生化系統(tǒng)發(fā)揮功效進而實現(xiàn)全面穩(wěn)定達標排放的關鍵,原含硫廢水預處理采用“催化氧化+混凝沉淀”工藝,受pH、催化劑投加量、催化氧化時間、供氧量、溫度等諸多因素影響,其中工程建設時一般不采取催化氧化反應加溫措施,致使冬季低溫時催化氧化效率降低而對含硫廢水預處理不徹底,造成綜合廢水中硫化物含量超過微生物抑制濃度;優(yōu)化后含硫廢水預處理采用“催化氧化+化學沉淀”工藝,即使催化氧化反應試驗溫度10℃時,也可使預處理后含硫廢水平均出水COD_(Cr)3589mg/L、去除效率70.2%,S2-41.2mg/L、去除效率96.7%,完全滿足綜合廢水生化系統(tǒng)正常穩(wěn)定運行條件。原綜合廢水采用“物化+兩級A/O+好氧”組合主體處理工藝,其中“兩級A/O+好氧”構成的兩段好氧均為活性污泥法,平均出水COD_(Cr)270mg/L、去除效率88.5%,NH_4~+-N60mg/L、去除效率82.9%,TN180mg/L、去除效率63.6%,難以使污水處理站出水水質TN指標達到GB30486-2013《制革及毛皮加工工業(yè)水污染物排放標準》表2新建企業(yè)間接排放限值140mg/L的規(guī)定要求;優(yōu)化后綜合廢水采用“物化+兩級A/O+厭氧/生物接觸氧化+物化”組合主體處理工藝,即將原后段好氧改造成厭氧/生物接觸氧化,形成獨特的泥膜混合法,通過高效微生物載體,提高了整個生化處理系統(tǒng)去碳脫氮能力,再輔以物化處理單元進行混凝沉淀,平均出水COD_(Cr)175mg/L、去除效率93.5%,NH_4~+-N35mg/L、去除效率90.3%,TN80mg/L、去除效率86.6%,確保了污水處理站各項出水水質指標全面穩(wěn)定達標排放。
[Abstract]:Leather industry is a pillar industry in light industry of our country, and it is also a serious pollution industry. Tannery wastewater contains high concentration of protein, fat, sodium sulfide, chrome tanning agent, dyestuff, inorganic salt, lime and other chemical raw materials to make it more difficult to treat industrial wastewater. Although the HJ2003-2010 Technical Specification for the treatment of Tannery and Fur processing Wastewater has been implemented since March 1, 2011, the technical requirements for the design, construction, acceptance and operation management of the tannery wastewater treatment project are clearly stipulated. However, on March 1, 2014, the GB30486-2013 "discharge Standard of Water pollutants in Tannery and Fur processing Industry" has clearly increased the project indexes of characteristic pollutants such as total nitrogen which should be controlled emphatically in the discharge of tannery wastewater. It is imperative to improve the environmental protection management level of leather industry by tightening the emission limit and the standard water displacement index. Taking the 2500m3/d tannery wastewater treatment project of an annual production of 850000 genuine leather enterprises as an example, on the basis of mastering the pollution characteristics of various kinds of wastewater, design treatment load and process design parameters, the main problems in operation are explained through field debugging. Draw up the test plan, scientifically obtain the real causality of each process treatment unit, and then optimize and construct the combined treatment process which is comprehensive and stable to meet the discharge standard of each water quality index. It has positive practical significance for standardizing the treatment of tannery wastewater and realizing the sustainable and healthy development of the industry. The results show that the pretreatment of wastewater is the key to ensure the comprehensive wastewater biochemical system to exert its function and achieve the overall and stable discharge standard. The original sulfur-containing wastewater pretreatment adopts the process of "catalytic oxidation coagulation and sedimentation" and is added by pH, catalyst. The catalytic oxidation time, oxygen supply, temperature and so on are affected by many factors. In engineering construction, the catalytic oxidation reaction is not heated, which results in the reduction of catalytic oxidation efficiency at low temperature in winter and the incomplete pretreatment of sulfur-containing wastewater. The sulphide content in the wastewater exceeds the microbial inhibition concentration. The pre-treatment of sulfur-containing wastewater after optimization uses the process of "catalytic oxidation chemical precipitation". Even when the reaction temperature of catalytic oxidation test is 10 鈩，

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