Kinetic studies on phosphorus sorption by selected soil amendments for septic tank effluent renovation

A systematic kinetic study of phosphorus (P) sorption by various materials in the soil infiltration system of septic tanks was undertaken by following the time course of P sorption by sorbents in contact with various P solutions over periods up to 360 days. Uptake of P seemed to consist of two distinct stages. Initial uptake was very rapid and this phase was completed in 4 days or less. A slower removal stage followed for some materials over many months. Phosphorus sorption during the fast reaction stage appeared to be associated with the soluble Ca content of the materials. The fast reaction of calcareous materials accounted for the bulk (>70%) of the total P removed. Merribrook loamy sand exhibited the highest proportion of P sorption during the slow phase. It should be noted, however, that for solution P concentrations in the range found in typical effluents (∼ ∼20 mg L⁻¹) the fast reaction phase seemed to be responsible for virtually all P removed. None of the six kinetic formulae examined possessed the sophistication and detail needed to portray accurately the time course of P sorption for all the sorbents investigated. The Elovich equation and the kinetic modification of the Freundlich isotherm expression appeared to provide a reasonable fit of the experimental data.     

LAS对土壤中多环芳烃吸附行为的影响

研究了阴离子表面活性剂十二烷基苯磺酸钠（LAS）对PAHs在士壤中吸附行为的影响。结果表明，LAS改变了PAHs在土水体系中的吸附／解吸平衡，吸附态LAS可提高土壤对PAHs的吸附，而溶解态LAS则增加了PAHs的表观溶解度，这2种作用的综合结果改变了PAHs在土水体系中的吸附系数。凶此，文中用表观吸附系数来描述PAHs在土壤-水-LAS体系中的综合吸附行为。     

阿特拉津及其代谢物在砂质壤土中的吸附

采用批量平衡法研究了阿特拉津（AT）及其主要代谢物脱乙基阿特拉津（DEA）和脱异丙基阿特拉津（DIA）在砂质壤土中的吸附行为,讨论了离子强度和温度对吸附的影响.结果表明,3种化合物的吸附24h基本达到平衡,吸附量大小顺序为AT > DIA > DEA;二级动力学模型可以很好地预估平衡吸附容量和初始吸附速率常数,颗粒内扩散方程表明颗粒扩散不是唯一的控速手段,Elovich方程拟合所得AT、DEA和DIA的瞬时吸附占各自吸附总量的53%、85%和80%;Freundlich方程能很好地描述3种化合物在供试土壤中的吸附特性,吸附系数（K_f）范围为0.7992~1.3201mg^1-1/n·mL^1/n/kg,经验常数1/n范围为0.7440~0.7530.溶液的离子强度和温度影响土壤对化合物的吸附,温度升高,K_f值降低;CaCl₂从0~0.01mol/L,K_f值增大,再继续增加,吸附系数有降低的趋势.     

Respiratory Suspended Particulate (RSP) Concentration and its Implications to Roadside Workers: A Case Study of Hong Kong

The adsorption behaviour of Diphenylamine (DPAM), napthylamine ( NAM), napthylamine ( NAM)and aniline on pyrolusite and activated carbon has been studied.Pyrolusite shows remarkable sorption capacity for DPAM and NAM as compared to aniline; (the adsorption followed theorder:Activated Carbon: DPAM = NAM > AnilinePyrolusite: DPAM: NAM > NAM> Aniline)The maximum adsorption of NAM occurred in theconcentration range 4–20 g mL^-1 on pyrolusite (95%)and 4–50 g mL^-1 on activated carbon (100%). Theeffect of various doses of activated carbon on the adsorption of NAM confirm Langmuir and Freundlich isotherms where asFreundlich isotherm is obeyed by pyrolusite. The adsorption of NAM on both the absorbents is not affected in presence ofDPAM over a wide range of their initial concentrations (20–60g mL^-1). The desorption studies of NAM onpyrolusite was carried out by batch as well as column processes.Excellent results were obtained when a mixture of n-hexane andisopropanol (91:1) was used as eluent.     

一种新型环境矿物材料在废水治理中的应用研究--硅质磷块岩吸附水溶液中镉离子的研究

硅质磷块岩对水溶液中镉离子的吸附实验结果表明,硅质磷块岩对水溶性镉离子具有良好的去除效果,主要影响因素有介质的酸度、作用时间、镉离子的初始浓度和样品用量.在pH=6,作用时间为15 min,初始Cd2+浓度为30mg/L的实验条件下,硅质磷块岩对镉离子的去除率可达98%,有可能利用动态法进行工业废水的连续处理.初步研究结果显示,磷块岩对水溶性镉离子的吸附作用符合Langmuir等温吸附模型,不同产地的硅质磷块岩S1和S2对镉离子的最大吸附容量分别为4.43 mg/g和3.88 mg/g.     

人工神经网络模拟芳基脲土壤吸附系数研究

对38种芳基脲类化合物的土壤吸附系数进行了定量结构－活性相关研究。利用量子化学的AM1方法提取化合物的结构参数，运用多元回归分析和人工神经网络对该化合物进行比较研究。研究结果表明，神经网络法所得结果优于多元回归分析结果，并对分析结果进行了吸附机理讨论。     

Simulation study on vertical transport of atrazine in soil column

ＩｎｔｒｏｄｕｃｔｉｏｎＡｔｒａｚｉｎｅ (2 ｃｈｌｏｒｏ 4 ｅｔｈｙｌａｍｉｎｏ 6 ｉｓｏｐｒｏｐｙｌａｍｉｎｏ ｓ ｔｒｉａｚｉｎｅ)ｉｓｏｎｅｏｆｔｈｅｍｏｓｔｗｉｄｅｌｙｕｓｅｄｈｅｒｂｉｃｉｄｅａｎｄｍａｉｎｌｙｕｓｅｄｆｏｒｃｏｎｔｒｏｌｏｆｃｅｒｔａｉｎａｎｎｕａｌｂｒｏａｄｌｅａｆａｎｄｇｒａｓｓｗｅｅｄｓａｎｄｐｒｉｍａｒｉｌｙｈａｓｂｅｅｎｃｏｍｍｏｎｌｙｕｓｅｄｉｎｃｏｒｎｏｒｉｎｃｏｒｎ ｗｈｅａｔｄｏｕｂｌｅｃｒｏｐｐｉｎｇｓｙｓｔｅｍｉｎＮｏｒｔｈｅａｓｔａｎｄＮｏｒｔｈｏ…     

新型离子交换纤维去除水中砷酸根离子的研究

制备了一种新型离子交换纤维。研究表明,该离子交换纤维对砷酸根离子具有较高的吸附容量和较快的吸附速度,吸附动力学数据完全符合Lagergren二级速度方程,在所研究的砷浓度范围内,Freundlich型吸附等温式能很好地描述吸附平衡数据,去除砷酸根离子的最佳pH值范围是3．5－7．0。离子交换纤维柱吸附实验表明了较好的动态附特性,稀NaOH溶液是砷酸根离子的有效洗脱剂,30mL 0.5mol/L NaOH溶液可定量将96．0mg/g吸附量的砷从纤维柱上洗脱。     

Zr、Hf在水合氧化铁上的吸附实验研究

制备了两种不同n(Zr)／n(Hf)的Zr、Hf混合溶液,测定了实时生成的水合氧化铁和预先生成的水合氧化铁在不同pH条件下对Zr、Hf的吸附量,并对其吸附等温线进行了研究。研究结果表明:等价元素Zr、Hf在HFO上的吸附是非线性的,在吸附过程中二者发生了分异,Zr的吸附能力要大于Hf;在天然水体pH值范围内(pH≥6),Zr、Hf的吸附量Q及n(Zr)／n(Hf)不随pH发生变化,显示了Zr、Hf相对惰性的行为;Zr、Hf在吸附过程中表现出惊人的一致性行为,Zr、Hf数据间的相关系数R2在0.98以上;Zr、Hf在HFO上的吸附可能是表面羟基与Zr、Hf表面络合反应的结果,并且络合能力Zr>Hf。     

Cr3+改性膨润土对苯胺的吸附性能研究

研究了Cr^3 改性膨润土吸附苯胺的性能及适宜条件．结果表明，Cr^3 改性膨润土对苯胺具有很好的吸附效果，吸附过程很快达到平衡，酸性和中性环境均有利于吸附过程的进行．绘制了不同初始浓度下苯胺溶液在平衡浓度达国家工业废水第二类污染物三级排放标准和二级排放标准时，Cr^3 改性膨润土的用量和吸附等温线，并将吸附效果与原钙基膨润土、钠化膨润土和有机改性膨润土进行了对比。