Call for Comments on the Sinopec Water Treatment Agent Procurement Standards
Thread Content
1.1 The quality of 2,2-dibromo-3-azidopropionamide shall meet the technical requirements specified in Table 1. Technical requirements for 2,2-dibromo-3-nitrosopropamideItem Specification
Solid Type I Type II
Appearance White crystalline powder Transparent to amber liquid Transparent to amber liquid
Mass fraction of active ingredient (based on DBNPA)/% ≥99.0 5.0–7.0 20.0–22.0
pH 4.0–6.0 3.0–5.0 3.0–5.0
Density (20°C)/（g/cm3） – 1.10–1.20 1.20–1.30
Mass fraction of moisture/% ≤1.0 – –
Table 1: The inert component is polyethylene glycol; highly toxic diethylene glycol shall not be used. Contact unit: Water Treatment Chemicals Evaluation Center of Sinopec Group Corporation, No. 15, Fenghuangting Road, Yanshan, Fangshan District, Beijing, Postal Code: 102500. Telephone: 010-80344972 / 69341927. Fax: 010-80344867. Contact person: Zhang Jianmei. Deadline: November 30, 2010. E-mail: zhangjm05.bjhy@sinopec.com. Solicitation of opinions on the “Sinopec Water Treatment Chemicals Procurement Standards”. 21. Product classification: This product is divided into two categories. Class I: Prepared using glutaraldehyde and quaternary ammonium salts as the main active components. Class II: Prepared using glutaraldehyde as the main active component. 4.1 The quality of glutaraldehyde-based composite fungicides shall meet the technical requirements specified in Table 1. Table 1 Technical requirements for glutaraldehyde-based composite bactericides Item Specifications Class I Class II Appearance Homogeneous liquid, no precipitates Active ingredient Mass fraction of glutaraldehyde/% ≥ 10.0 15.0 Mass fraction of quaternary ammonium salt a (based on 1227)/% ≥ 5.0 – Formaldehyde (qualitative) Not detectable/
This post was last edited by cdpulin on 2010-11-14 at 20:43. Engineer Zhang, I saw you here and have a question to ask. I work for Baling Company; for determining COD in circulating water, the manganese method is generally used, while for wastewater discharge, the rapid spectrophotometry method specified by the Ministry of Environment is employed. The results obtained from these two analysis methods differ significantly, and since they are based on different standards, it’s difficult to standardize the analyses, which hinders efforts to ensure compliance with emission regulations. For example, the COD standard for sewage discharge is set at less than 60; the COD value measured using the manganese method for recycled water is usually around 5, which meets the standard. However, when the chromium method is used, this value may exceed 60. The recycled water system considers such levels to be within the acceptable range, while the sewage treatment system considers them to be above the standard. The monthly reports required by headquarters specify the use of the manganese method. How can this contradiction be resolved? Guidance is appreciated. My email is wuwang008@sina.com, thank you
The manganese method is primarily used for determining COD in water, via the potassium permanganate method, and is often employed for measuring COD in surface water. Chromium methods, namely the potassium dichromate method, are commonly used for wastewater treatment. The oxidizing power of the potassium dichromate method is much stronger than that of the potassium permanganate method; therefore, for the same water sample, the results obtained using these two methods differ significantly, with the potassium dichromate method yielding higher values.
The circulating water changes rapidly; generally, one cycle is completed in 25–40 minutes. Therefore, a fast detection speed is required. The Mn method takes around 30 minutes, which is sufficient to meet the requirements of circulating water. As long as the capacity of the monitoring tank is sufficient, wastewater can generally be stored for an extended period of time, with accurate data being required. The Cr method usually takes a little over 3 hours. Therefore, these two methods are determined based on different water conditions and requirements.