NOTICE OF 2023 ANNUAL GENERAL MEETING

Hong Kong Exchanges and Clearing Limited and The Stock Exchange of Hong Kong Limited take no responsibility for the contents of this notice make no representation as to its accuracy or completeness and expressly disclaim any liability whatsoever for any loss howsoever arising from or in reliance upon the whole or any part of the contents of this notice.Datang Environment Industry Group Co. Ltd.* (A joint stock company incorporated in the People’s Republic of China with limited liability) (Stock Code: 1272) NOTICE OF 2023 ANNUAL GENERAL MEETING NOTICE IS HEREBY GIVEN that the annual general meeting of Datang Environment Industry Group Co. Ltd.* (the “Company”) for the year of 2023 (the “2023 AGM”) will be convened at 3:30 p.m. on Friday 28 June 2024 at No. 120 Zizhuyuan Road Haidian District Beijing the PRC for the purpose of considering and if thought fit passing the following matters (whether amended or not).Terms used in this notice shall have the same meanings as those defined in the circular of the Company dated 29 May 2024 (the “Circular”) unless otherwise specified.Ordinary Resolutions (1) To consider and approve the Report of the Board for 2023; (2) To consider and approve the Report of the Supervisory Committee for 2023; (3) To consider and approve the Independent Auditor’s Report and the Audited Financial Statements for 2023; (4) To consider and approve the Final Financial Accounts for 2023; (5) To consider and approve the Financial Budget Report for 2024; (6) To consider and approve the Profit Distribution Plan for 2023 and the Proposed 2023 Final Dividend; (7) To consider and approve the Remuneration Reports for Directors and Supervisors for 2023; and (8) To consider and approve the Investment Plan for 2024. * For identification purpose only - 1 -Special Resolution (9) To consider and approve the Proposed Amendments to the Articles of Association. The main texts of resolutions at the 2023 AGM are set forth in the Circular which is available on the website of the Stock Exchange (www.hkexnews.hk) and on the website of the Company (www.dteg.com.cn).By order of the Board Datang Environment Industry Group Co. Ltd.* Zhu Liming Chairman Beijing the PRC 29 May 2024 As of the date of this notice the executive Director is Mr. Zhu Liming; the non-executive Directors are Mr. Wang Junqi Mr. Shen Zhen Mr. Wu Daqing Mr. Chen Kan and Mr. Song Yunpeng; and the independent non-executive Directors are Mr. Ye Xiang Mr. Mao Zhuanjian and Mr. Gao Jiaxiang.Notes: i. In order to ascertain the entitlements of the Shareholders to attend and vote at the 2023 AGM the register of members of the Company will be closed from Tuesday 25 June 2024 to Friday 28 June 2024 (both days inclusive). Shareholders whose names appear on the register of members of the Company on Friday 28 June 2024 are entitled to attend and vote at the 2023 AGM.To be eligible to attend and vote at the 2023 AGM all transfer documents must be lodged with the H Share Registrar Computershare Hong Kong Investor Services Limited at Shops 1712-1716 17th Floor Hopewell Centre 183 Queen’s Road East Wanchai Hong Kong (for holders of H Shares) or the Company’s board office in the PRC at No. 120 Zizhuyuan Road Haidian District Beijing the PRC 100097 (for holders of Domestic Shares) no later than 4:30 p.m. on Monday 24 June 2024. ii. Each Shareholder entitled to attend and vote at the 2023 AGM may by completing the form of proxy of the Company appoint one or more proxies to attend and vote at the 2023 AGM on its behalf. A proxy need not be a Shareholder. With respect to any Shareholder who has appointed more than one proxy the proxy holders may only vote on a poll.iii. The instrument to appoint a proxy shall be signed by the appointer or his/her attorney duly authorised in writing or in the case of a legal person must be either executed under its common seal or under the hand of its directors or attorney duly authorised.iv. To be valid the form of proxy must be lodged with the H Share Registrar Computershare Hong Kong Investor Services Limited at 17M Floor Hopewell Centre 183 Queen’s Road East Wanchai Hong Kong (for holders of H Shares) or the Company’s board office in the PRC at No. 120 Zizhuyuan Road Haidian District Beijing the PRC 100097 (for holders of Domestic Shares) within 24 hours prior to the holding of the 2023 AGM. If such instrument is signed by another person under a power of attorney or other authorisation documents given by the appointer such power of attorney or other authorisation documents shall be notarised. The notarised power of attorney or other authorisation documents shall - 2 -together with the instrument appointing the proxy be deposited at the specified place at the time set out in such instrument. Completion and return of the proxy form will not preclude Shareholders from attending and voting in person at the 2023 AGM or any adjourned meetings should you so wish.v. Shareholders shall produce their identity documents and supporting documents in respect of Shares held when attending the 2023 AGM. If corporate Shareholders appoint authorised representative to attend the 2023 AGM the authorised representative shall produce his/her identity documents and a notarised certified copy of the relevant authorised documents signed by the Board or other authorised parties of the Shareholders or other notarised certified documents allowed by the Company. Proxies shall produce their identity documents and the proxy forms signed by the Shareholders or their attorney when attending the 2023 AGM. vi. The Company has the rights to request a proxy who attends the 2023 AGM on behalf of a Shareholder to provide proof of identity.vii. The 2023 AGM is expected to be held for less than half a day. Shareholders who intend to attend the 2023 AGM shall bear their own transportation and accommodation expenses. viii. In case of joint Shareholders the vote of the most senior one (in person or by proxy) will be accepted to the exclusion of the votes of other joint Shareholders and for this purpose the seniority shall be determined by the order in which the names of such joint Shareholders stand in the register of members of the Company.ix. H Share Registrar Computershare Hong Kong Investor Services Limited is situated at Shops 1712- 1716 17th Floor Hopewell Centre 183 Queen’s Road East Wanchai Hong Kong and with the fax number: +852 2865 0990.x. The contact details of the Company’s board office in the PRC are as follows: Address: No. 120 Zizhuyuan Road Haidian District Beijing the PRC 100097 Fax number: +86 10 5838 9860 xi. All dates and time in this notice refer to Hong Kong dates and time.