某皮革厂皮革废水处理工程案例分析

皮革废水属于高浓度难降解有机工业废水,具有排放水量大、水质水量不均、污染物成分复杂等特点,给皮革废水处理带来极大的难度。以河北省辛集市某皮革厂废水处理工程为例,简要描述了该皮革厂皮革的生产工序、废水水量及水质特征,重点论述了皮革废水的处理方法、投资费用、运行费用及运行效果,并对该工艺所采用的理念、方法及效果进行了探讨。     

猪粪污厌氧发酵沼液SS、COD的混凝预处理效果研究

通过混凝沉淀试验,运用无机、有机高分子混凝剂对猪粪污厌氧发酵沼液进行预处理,考察其悬浮物(SS)和COD的去除效果,探索混凝沉淀工艺对降低该类沼液后续处理难度的可行性。研究表明,投加2.6 g/L混凝剂N可去除沼液SS为44.9%~67.6%,同时添加5.0 mg/L阳离子型助凝剂,SS去除率最高,并同时可去除COD为33.3%,添加阳离子型助凝剂对SS和COD的去除均具有较好的促进作用,混凝沉淀处理后沼液SS与COD呈极显著正相关,说明可通过对SS进行优化去除的方式进一步协同削减沼液COD。     

基于污水处理的微藻培养研究进展

培养生长速度快、环境适应性强的微藻与污水处理工艺的联合应用具有理想的经济、环境和社会效益。阐述了利用微藻进行污水净化的国内外研究现状,并对可进行微藻培养的污水特点、污水预处理方法及藻体高附加值产物利用等方面进行分析,最后对微藻处理污水并获得的生物质原料方面的应用进行展望。     

Improving biodegradation potential of domestic wastewater by manipulating the size distribution of organic matter

Carbon source is a critical constraint on nutrient removal in domestic wastewater treatment. However, the functions of particulate organic matter (POM) and some organics with high molecular weight (HMW) are overlooked in the conventional process, as they cannot be directly assimilated into cells during microbial metabolism. This further aggravates the problem of carbon source shortage and thus affects the effluent quality. Therefore, to better characterize organic matter (OM) based MW distribution, microfiltration/ultrafiltration/nanofiltration (MF/UF/NF) membranes were used in parallel to fractionate OM, which obtained seven fractions. Hydrolysis acidification (HA) was adopted to manipulate the MW distribution of dissolved organic matter (DOM) and further explore the correlation between molecular size and biodegradability. Results showed that HA pretreatment of wastewater not only promoted transformation from POM to DOM, but also boosted biodegradability. After 8 hr of HA, the concentration of dissolved organic carbon (DOC) increased by 65%, from the initial value of 20.25 to 33.48 mg/L, and the biodegradability index (BOD5 (biochemical oxygen demand)/SCOD (soluble chemical oxygen demand)) increased from 0.52 to 0.74. Using MW distribution analysis and composition optimization, a new understanding on the characteristics of organics in wastewater was obtained, which is of importance to solving low C/N wastewater treatment in engineering practice.     

Advanced treatment of wet-spun acrylic fiber manufacturing wastewater using three-dimensional electrochemical oxidation

A three-dimensional electrochemical oxidation(3D-EC) reactor with introduction of activated carbon(AC) as particle micro-electrodes was applied for the advanced treatment of secondary wastewater effluent of a wet-spun acrylic fiber manufacturing plant. Under the optimized conditions(current density of 500 A/m~2, circulation rate of 5 mL/min, AC dosage of 50 g, and chloride concentration of 1.0 g/L), the average removal efficiencies of chemical oxygen demand(COD_(cr)), NH3–N, total organic carbon(TOC), and ultraviolet absorption at 254 nm(UV_(254)) of the 3D-EC reactor were 64.5%, 60.8%, 46.4%, and 64.8%, respectively; while the corresponding effluent concentrations of COD_(cr), NH_3–N, TOC, and UV_(254) were 76.6, 20.1, and42.5 mg/L, and 0.08 Abs/cm, respectively. The effluent concentration of COD_(cr) was less than 100 mg/L, which showed that the treated wastewater satisfied the demand of the integrated wastewater discharge standard(GB 8978-1996). The 3D-EC process remarkably improved the treatment efficiencies with synergistic effects for COD_(cr), NH_3–N, TOC, and UV_(254) during the stable stage of 44.5%, 38.8%, 27.2%, and 10.9%, respectively, as compared with the sum of the efficiencies of a two-dimensional electrochemical oxidation(2D-EC) reactor and an AC adsorption process, which was ascribed to the numerous micro-electrodes of AC in the 3D-EC reactor. Gas chromatography mass spectrometry(GC–MS) analysis revealed that electrochemical treatment did not generate more toxic organics, and it was proved that the increase in acute biotoxicity was caused primarily by the production of free chlorine.     

石化废水易降解成分对活性污泥耗氧抑制毒性评价的干扰因素

为评价某石化混合废水的毒性,采用活性污泥耗氧速率抑制试验研究不同φ(石化废水)对活性污泥中不同菌群的抑制及其影响因素. 结果表明,所用石化废水对活性污泥中的硝化细菌具有明显毒性,其EC₅₀(半抑制效应浓度,以φ计)为9%左右;同时,该废水对异养菌的耗氧具有较强的促进作用,φ(石化废水)为100%时I_H(异养菌耗氧速率抑制率,131%)最高,这种促进作用对R_T(总耗氧速率)测定有显著影响(R=0.991,P<0.05),因此,仅以R_T评价废水毒性容易造成对废水真实毒性的低估. 5种常见易降解基质(乙酸钠、葡萄糖、甲醇、生活污水、丙酸钠)中,ρ(甲醇)为15 mg/L时对异养菌促进效果显著(P<0.05),促进率达50%以上;而在高浓度条件下,乙酸钠、葡萄糖、甲醇、丙酸钠对异养菌均有显著促进作用(P<0.05),R_H(异养菌耗氧速率)最高提高了182%. 研究显示,石化废水中的乙酸盐等易降解成分是活性污泥耗氧速率抑制试验的重要干扰因素.      

一株石油降解赤红球菌(Rhodococcus rubber)特性及处理含油废水研究

从石油污染土壤筛选出一株高效石油降解菌JC-106,经细菌形态学、生理生化及16S r DNA序列分析鉴定为赤红球菌(Rhodococcus rubber).在温度15~40℃、初始p H 6~8、盐度0~4%条件下培养生长良好.该菌能利用十二烷、二十四烷、正辛烷、邻苯二酚、蒽、萘为唯一碳源生长.在较低温度下能有效降解原油,在15和35℃培养15 d对原油降解率分别为41.61%和58.18%,GC-MS分析发现原油组分中正构烷烃(C14~C44)降解率达到96.13%.在含1000 mg·L~(-1)原油的人工废水中加入2%(V/V)赤红球菌JC-106菌悬液,采用SBR间歇式活性污泥法处理含油废水,15 d后出水COD、NH_4+-N、TP平均去除率分别为96.49%、96.88%、99.15%,原油去除率为92.43%,对照组原油去除率仅为53.80%.JC-106在含油废水中稳定生长,数量维持在4.8×1010~1.0×1011cfu·mL~(-1)左右.     

生物接触氧化-滴滤工艺处理水产养殖废水的效能研究

为了高效处理水产养殖废水,采用了生物接触氧化-滴滤(以陶粒为滤料)组合工艺,并对该组合工艺的处理效果进行考察。以生物接触氧化池中组合填料的密度、停留时间以及滴滤的水力负荷作为研究对象,通过对CODMn、氨氮、TN等参数的分析,得到了该组合工艺的处理效果。研究表明:当工艺中组合填料密度(组合填料与废水的体积比)为9.24%,生物接触氧化水力停留时间为0.85 h,滴滤的水力负荷为27.2 m3/(m2·d)时,CODMn、氨氮、TN、TP的去除率可分别高达55.31%、34.31%、57.64%和20.25%。证明采用该组合工艺净化水产养殖废水具有可行性。     

磁分离技术在水处理中的研究与应用进展

磁分离技术具有分离速率快、效率高、无二次污染、占地少、投资低、操作方便等优点,在水处理领域得到了越来越多的研究和应用,特别是随着超导高梯度磁分离技术以及磁分离器设计的进一步发展,其在水处理领域极具潜能.因此,本文通过文献调研,分析和总结了目前主要磁分离技术(例如,磁场直接应用、磁絮凝-磁分离、磁吸附-磁分离、磁催化-磁分离及磁分离耦合技术)在水处理领域的研究进展,介绍了近年来磁分离技术在国内水处理行业中的研究与实际工程应用推广现状,分析了磁分离技术应用于水处理领域的优势和当前应用中存在的限制,并对其未来发展方向进行了展望.虽然磁分离技术目前已经成为水处理领域一项广泛应用的分离技术,但在机理研究、特异性磁种制备、磁体技术与磁分离器设计、磁分离工艺优化及实际的工程应用推广上仍存在一定的滞后,需要进一步的开展研究工作.     

含硫废水受控氧化及单质硫团聚过程研究

采用过氧化氢在常温常压下对模拟含硫废水进行受控氧化,探讨了受控氧化过程对单质硫收率的影响,并对氧化过程中固相产物的形态特性进行了研究.结果表明,在过氧化氢投加量为9 m L·L-1、初始p H为6、反应时间为10min条件下,将反应体系氧化还原电位(ORP)控制在(30±5)m V时能较好实现含硫废水的受控氧化,此时单质硫收率达76.35%,当体系ORP由(-50±5)m V升高至(50±5)m V时,副产物S2O2-3收率显著下降,由26.54%下降至5.32%.X射线衍射分析表明,氧化过程中的固相产物主要为正交晶系斜方硫;扫描电子显微镜分析表明,液相中的单质硫由多个极小的颗粒聚集而成,其粒径由纳米级逐渐增大至微米级.同时,通过向反应体系中加入分散剂证明了单质硫颗粒增大的主要原因是颗粒间发生了团聚.